The s a us o biological in asions
and hei managemen in
Sou h A ica in 2022
2022
Lead edi o s: Tsungai A. Zengeya1,2, John R. Wilson1,3
Chap e lead au ho s: Ka elyn T. Faulkne 1,4, Lau a Fe nández Winze 1,3, Michelle G e e5, Sab ina Kumschick1,3, Emily J. McCull-
och-Jones1,3, Siyasanga Miza1, Pe e C. le Roux5, Ma hán Thea 6, B ian W. an Wilgen3, John R. Wilson1,3 & Tsungai A. Zengeya1,2
Wi h con ibu ions om: Julie A. Coe zee7, Nicholas Cole8, Whi ney Engelb ech 1, Ma in P. Hill9, Ca ol Jacobs6, Cha lene Jan-
ion-Scheepe s10, Phe ole Manyama1, Themba G. Mnguni6, Zacha iah Mokganye6, Debbie Mui 6, Wilma J. Nel11, T udy Paap11, Iain D.
Pa e son9, Mashudu V. Phalanndwa12, Leoni P e o ius13, Roge E. P ice13, Tama a B. Robinson3, A iwe Si uba1, Louise S a o d14, Anne
M. T easu e15,16, And ew A. Tu ne 17, Ka abo Wanjau6, And ew Wannenbu gh6, Mike J. Wing ield11, An on C. Wol aa d 18 & Cos as Zach-
a iades13,19
Re e ence and Ad iso y Commi ee: Kay Mon gome y20 (Chai ), Amanda D i e 1, Llewellyn C. Foxc o 8,3, The essa F an z1, Lele hu
U.P. Heshula21, Ma in P. Hill9, Ba ney Kgope6, Bonani Madikizela22, Je ey Manuel1, Phyllys as R. Mmakola23, Mpume N lokwana23,
And ew L. Skowno1, Fa ai Te e ai1,3 & And ew Wannenbu gh6
Expe e iew o he e ised d a : Andy W. Sheppa d & E ol Douwes
Technical edi ing: Nicole L. Meye
P oo eade : Yolande S eenkamp
Design, layou & co e design: Elizma Fouché
Co e pho og aphs: (clockwise om op le ): Lan ana cama a (© Juan Ca los Fonseca Ma a); Mic op e us salmoides
(©Ma nus E asmus); Acacia saligna (© Suzaan K i zinge -Kloppe ); My ilus gallop o incialis (©Ta-
ma a Robinson); Euwallacea o nica us (© Ga yn Townsend); Psi acula k ame i (© De ek Kea s)
Inside co e pho og aph: Caesalpinia gilliesii (© SAPlan s)
Ci ing his publica ion:
Fo ci a ions in he scien i ic li e a u e: Zengeya, T.A. & Wilson, J.R. (eds). 2023. The s a us o biological in asions and hei man-
agemen in Sou h A ica in 2022. Sou h A ican Na ional Biodi e si y Ins i u e, Ki s enbosch and DSI-NRF Cen e o Excellence o
In asion Biology, S ellenbosch. pp. 122. h p://dx.doi.o g/10.5281/zenodo.8217182.
Fo ci a ions in policy documen s: SANBI and CIB. 2023. The s a us o biological in asions and hei managemen in Sou h A ica
in 2022. Sou h A ican Na ional Biodi e si y Ins i u e, Ki s enbosch and DSI-NRF Cen e o Excellence o In asion Biology, S el-
lenbosch. pp. 122. h p://dx.doi.o g/10.5281/zenodo.8217182.
Example o a ci a ion o an indi idual chap e : Faulkne , K. T. 2023. Chap e 1: Pa hways. In Zengeya, T.A. & Wilson, J.R. (eds), The
s a us o biological in asions and hei managemen in Sou h A ica in 2022. Sou h A ican Na ional Biodi e si y Ins i u e, Ki s en-
bosch and DSI-NRF Cen e o Excellence o In asion Biology, S ellenbosch. pp. 15–25. h p://dx.doi.o g/10.5281/zenodo.8217182.
ISBN: 978-1-928224-67-9
P in ed by: Ha y’s P in e s Tshwane, 69 P e o ius S ee , P e o ia, 0002 Sou h A ica; el. no. +27 12 326 4514.
Copy igh © (2024) Sou h A ican Na ional Biodi e si y Ins i u e (SANBI). Tel.: +27128435000. Websi e: www.sanbi.o g.
All igh s ese ed. No pa o his epo may be ep oduced in any o m wi hou w i en pe mission o he copy igh owne s.
This wo k is licensed unde CC BY-NC 4.0.
The iews and opinions exp essed do no necessa ily e lec hose o SANBI. The publishe has made hei bes e o s o p epa e his epo and
makes no ep esen a ion o wa an ies o any kind wi h ega d o he comple eness o accu acy o he con en s he ein. All images in his epo ha e
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1Sou h A ican Na ional Biodi e si y Ins i u e
2DSI-NRF Cen e o Excellence o In asion Biology, Depa men o Zo-
ology and En omology, Uni e si y o P e o ia
3DSI-NRF Cen e o Excellence o In asion Biology, Depa men o Bo -
any and Zoology, S ellenbosch Uni e si y
4Depa men o Zoology and En omology, Uni e si y o P e o ia
5Depa men o Plan and Soil Sciences, Uni e si y o P e o ia
6Depa men o Fo es y, Fishe ies and he En i onmen
7Cen e o Biological Con ol, Bo any Depa men , Rhodes Uni e si y
8Sou h A ican Na ional Pa ks
9Cen e o Biological Con ol, Depa men o Zoology and En omolo-
gy, Rhodes Uni e si y
10Depa men o Biological Sciences, Uni e si y o Cape Town
11Fo es y and Ag icul u al Bio echnology Ins i u e, Depa men o Bio-
chemis y, Gene ics and Mic obiology, Uni e si y o P e o ia
12Ci y o Cape Town
13Ag icul u al Resea ch Council – Plan Heal h and P o ec ion
14The Na u e Conse ancy
15Sou h A ican Pola Resea ch In as uc u e
16Depa men o Bo any and Zoology, S ellenbosch Uni e si y
17CapeNa u e
18Bi dLi e Sou h A ica
19School o Li e Sciences, Uni e si y o KwaZulu-Na al
20In asi e Species Sou h A ica
21Depa men o Zoology and En omology, Uni e si y o Fo Ha e
22Wa e Resea ch Commission
23Depa men o Ag icul u e, Land Re o m and Ru al De elopmen
iii
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table o Con en s
Fo ewo d by he Minis e o Fo es y, Fishe ies and he En i onmen ......................................... i
P e ace by he Chai o he Boa d o he Sou h A ican Na ional Biodi e si y Ins i u e .......................... iii
P e ace by he Chie Execu i e O ice o he Sou h A ican Na ional Biodi e si y Ins i u e ..................... x
Lis o ac onyms ............................................................................................ xii
Glossa y .................................................................................................... xiii
Summa y o key messages .................................................................................. x i
Table o key messages ................................................................................. x ii
A) How alien species a e in oduced and mo e a ound he coun y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
B) The s a us and impac s o alien species ........................................................... xxi
C) How si es a e in aded and impac ed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii
D) Wha has been done o add ess he p oblem ..................................................... xx
E) The s a us and managemen o in asions in he P ince Edwa d Islands ............................. xx iii
In oduc ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The signi icance o biological in asions o Sou h A ica ................................................. 1
Sou h A ica’s egula o y amewo k ega ding biological in asions and he speci ic manda e o he hi d
s a us epo ..................................................................................... 1
The b oade manda e, pu pose and s uc u e o he hi d s a us epo .................................. 2
The ‘Summa y o key messages’ and communica ing he deg ee o con idence .......................... 4
P ocess o he compila ion o he epo ............................................................... 6
Indica o s ............................................................................................. 9
Wo k lows and p o ocols .............................................................................. 10
Aspec s o biological in asions ha a e no co e ed .................................................... 12
Box 0.1.
The In e go e nmen al Science-Policy Pla o m on Biodi e si y and Ecosys em Se ices’ Thema ic
Assessmen Repo on In asi e Alien Species and hei Con ol (IPBES IAS Assessmen )
........... 12
Box 0.2. The Kunming-Mon eal Global Biodi e si y F amewo k (GBF) o he Con en ion on Biological Di-
e si y (CBD) ................................................................................. 12
Chap e 1: Pa hways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Findings o pa hways ................................................................................. 15
Gap o pa hways ...................................................................................... 15
Indica o s co e ed in he pa hways chap e ............................................................ 16
1.1 In oduc ion pa hway p ominence ............................................................... 16
1.2 In oduc ion a es ................................................................................ 18
1.3 Wi hin-coun y pa hway p ominence ............................................................. 20
1.4 Wi hin-coun y dispe sal a es .................................................................... 20
Box 1.1. Wo k o imp o e he pa hway indica o s ...................................................... 22
1.5 T ends in pa hway indica o s ..................................................................... 23
Chap e 2: Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Findings o species ................................................................................... 27
Gaps o species and si es .............................................................................. 28
i
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o s co e ed in he species chap e .............................................................. 28
2.1 Numbe and s a us o alien species ............................................................... 28
2.2 Ex en o alien species ............................................................................ 29
2.3 Abundance o alien species ...................................................................... 31
2.4 Impac o alien species ........................................................................... 32
Box 2.1. Na i e-alien popula ions ..................................................................... 33
2.5 T ends in species indica o s ...................................................................... 34
Chap e 3: Si es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Findings o si es ...................................................................................... 37
Gaps o species and si es .............................................................................. 38
Indica o s co e ed in he si es chap e ................................................................. 38
3.1 Alien species ichness ............................................................................ 38
3.2 Rela i e in asi e abundance ..................................................................... 40
3.3 Impac o in asions .............................................................................. 42
Box 3.1. Es ima ing he mone a y cos o biological in asions o Sou h A ica .......................... 43
3.4 T ends in si es indica o s ......................................................................... 44
Chap e 4: In e en ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Findings o in e en ions ............................................................................. 47
Gaps o in e en ions ................................................................................. 48
Indica o s co e ed in he in e en ions chap e ........................................................ 49
4.1 Inpu – quali y o he egula o y amewo k ....................................................... 49
4.2 Inpu – money spen ............................................................................. 52
4.3 Inpu – planning co e age ....................................................................... 56
4.4 Ou pu – pa hways ea ed ....................................................................... 59
4.5 Ou pu – species ea ed ......................................................................... 60
4.6 Ou pu – si es ea ed ............................................................................ 62
4.7 Ou come – e ec i eness o pa hway ea men s .................................................. 63
4.8 Ou come – e ec i eness o species ea men s ................................................... 64
4.9 Ou come – e ec i eness o si e ea men s ....................................................... 65
Box 4.1. The egula ion o in asi e species used in comme cial imbe plan a ions ..................... 66
Box 4.2. The G ea e Cape Town Wa e Fund ........................................................... 67
Box 4.3. Success ul biological con ol o wa e hyacin h on a eu ophic sub opical wa e body .......... 68
4.10 T ends in in e en ions indica o s ................................................................ 69
Chap e 5: The s a us o biological in asions and hei managemen in he P ince Edwa d Islands . . . . . . . 75
Findings o he P ince Edwa d Islands (PEIs) ........................................................... 75
Gaps o he PEIs ...................................................................................... 76
Indica o s co e ed in he PEIs chap e .................................................................. 77
5.1 Pa hways ........................................................................................ 78
5.2 Species .......................................................................................... 82
5.3 Si es ............................................................................................. 85
5.4 In e en ions .................................................................................... 87
5.5 T ends in indica o s o he PEIs ................................................................... 93
Chap e 6: Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Chap e s uc u e and gaps ............................................................................ 101
6.1 P og ess since he las epo ..................................................................... 102
6.2 Indica o s – imp o ing how in asions a e measu ed and p o iding a link o o he epo s .......... 107
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
6.3 Pa hways – acking in asions ac oss Sou h A ica ................................................. 107
6.4 Species and si es – mapping in asions in space and o e ime ..................................... 107
6.5 Species and si es – de e mining he impac s and cos s ............................................ 107
6.6 In e en ions – he need o an o e a ching policy and s a egy ................................... 108
6.7 In e en ions – measu ing e ec i eness .......................................................... 108
6.8 Gaps iden i ied in he book Biological in asions in Sou h A ica ..................................... 109
6.9 Sugges ions o addi ional wo k o ex ensions o he scope o he epo .......................... 109
6.10 The way o wa d ................................................................................. 111
Acknowledgemen s ........................................................................................ 112
Re e ences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Links o supplemen a y ma e ial and appendices ............................................................ 122
Passi lo a edulis (© Dinesh Valke).
i
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Ms Ba ba a C eecy, MP
Biological in asions a e a signi ican and g owing h ea o Sou h
A ica’s na u al, ag icul u al and u ban ecosys ems, as well as hu-
man li elihoods. Gi en he impo ance o hese in asions, i is
i al o us o egula ly assess hei s a us, as well as he e ec-
i eness o ou ini ia i es o espond o he p oblem. The Sou h
A ican Na ional Biodi e si y Ins i u e has aken he lead in p o-
ducing hese epo s, wi h suppo om a wide ange o en i ies
wi hin na ional, p o incial and local go e nmen , as well as he
p i a e sec o . Sou h A ica can ake p ide in he ac ha i is
he only coun y globally ha egula ly epo s on he h ea o
biological in asions, and hei managemen a a na ional le el. In
addi ion, my depa men p o ides subs an ial suppo o bo h
s a e and p i a e landowne s o assis hem wi h he manage-
men o in asi e alien species, while also c ea ing much-needed
employmen oppo uni ies h ough he Expanded Public Wo ks
P og amme ha unds he Wo king o Wa e P og amme. Sou h
A ica has demons a ed ha we can achie e biodi e si y ou -
comes by managing he h ea s o alien and in asi e species,
while a he same ime c ea ing much-needed jobs.
The epo on he s a us o biological in asions and hei man-
agemen in Sou h A ica is published ollowing he launch in
Sep embe 2023 by IPBES o he i s comp ehensi e global as-
sessmen , he Thema ic assessmen epo on in asi e alien species
and hei con ol. The iming o his publica ion s a egically posi-
ions Sou h A ica o lea n om he IPBES p ocess, and o suppo
he implemen a ion o he Kunming-Mon eal Global Biodi e si-
y F amewo k and he Sus ainable De elopmen Goals.
The indings o his epo pain a sobe ing pic u e. Sou h A ica
is con on ed wi h a mul i ude o in asi e species ha ha e aken
oo in ou ecosys ems, al e ing na i e habi a s, ou compe ing
indigenous species, and dis up ing essen ial ecological p ocess-
es. These in ade s, in oduced h ough human ac i i ies such as
ade and a el, ha e demons a ed hei abili y o sp ead apid-
ly and w eak ha oc on ou agile ecosys ems.
I is essen ial o ecognise ha he impac s o biological in a-
sions ex end beyond he ealm o biodi e si y alone. They ha e
a - eaching consequences on ou economy, ag icul u e, wa e
esou ces and public heal h. In asi e species can de as a e ag-
icul u al lands, leading o educed c op yields and inc eased
p oduc ion cos s. They can also impai wa e quali y, clog wa e -
ways and impac on ou abili y o access clean d inking wa e .
Addi ionally, some in asi e species pose isks o human heal h
by ac ing as ca ie s o diseases o causing alle gic eac ions.
Fo ewo d by he Minis e o Fo es y,
Fishe ies and he En i onmen
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Acacia longi olia (© K zysz o Zia nek).
ii
Add essing he challenges posed by biological in asions equi es a coo dina ed and collabo a i e e o . No single en-
i y can ackle his issue alone. Go e nmen s, scien is s, ci il socie y o ganisa ions, communi ies and indi iduals mus
come oge he , pooling hei knowledge, esou ces and expe ise o de elop e ec i e p e en ion, ea ly de ec ion and
con ol s a egies.
Fo una ely, his epo also highligh s he p og ess we ha e made in managing biological in asions. Sou h A ica has
ecen ly e ised egula ions pe aining o he managemen o biological in asions. We ha e suppo ed nume ous e-
sea ch ins i u ions and ne wo ks dedica ed o s udying in asi e species and de eloping inno a i e managemen ech-
niques. Mo eo e , ou pa ne ships wi h in e na ional o ganisa ions and neighbou ing coun ies ha e s eng hened
ou collec i e abili y o comba his sha ed h ea .
The e is, howe e , s ill much wo k o be done. We mus enhance ou e o s o p e en he in oduc ion o new in a-
si e species h ough igilance a ou bo de s and isk analyses. Ea ly de ec ion and apid esponse sys ems should be
s eng hened o iden i y and e adica e in ade s be o e hey become es ablished. We mus con inue in es ing in e-
sea ch and inno a ion, suppo ing s udies ha enhance ou unde s anding o in asi e species dynamics and de elop
e ec i e managemen s a egies.
The na ional s a us epo on biological in asions se es as a cla ion call o ac ion. I eminds us o he u gency o he
si ua ion and he impe a i e o ac decisi ely. By wo king oge he , we can p o ec ou na u al he i age, es o e dam-
aged ecosys ems and secu e a sus ainable u u e o Sou h A ica.
As he Minis e esponsible o en i onmen al s ewa dship, I u ge all s akeholde s o emb ace he indings o his e-
po . Le us uni e in ou esol e o add ess he challenges o biological in asions, ensu ing ha Sou h A ica emains
a beacon o biodi e si y and a sanc ua y o ou p ecious indigenous plan s, animals and ecosys ems ha suppo
sus ainable de elopmen and human well being.
Toge he , we can make a di e ence.
xi
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Includes bo h na u al sp ead and he acciden al o in-
en ional illegal human-media ed dispe sal o li e o -
ganisms om he si e o cap i i y o cul i a ion.
es ablished: see na u alised.
ex en (c . abundance, dis ibu ion): he b oad-scale
a ea o e which an o ganism occu s. The spa ial scale
o e which ex en is measu ed needs o be speci ied.
The occupancy o si es a a ine-spa ial scale is o en
equi alen o he abundance.
ex alimi al: see na i e-alien popula ions
impac : he e ec o an alien species on he physical,
chemical and biological en i onmen . Impac can in-
clude bo h nega i e and posi i e e ec s.
incu sion: an isola ed popula ion o a pes , weed o
alien species ha usually has a limi ed spa ial ex en
and has been ecen ly de ec ed a a si e. In gene al, he
managemen o incu sions is e e ed o as incu sion e-
sponse.
indica o : a se o measu emen s ha gi e speci ic in o -
ma ion abou he s a e o some hing.
in e en ions: he ull a ie y o ac ions aken in e-
sponse o biological in asions, including di ec ac ions,
e.g., con ol and indi ec ac ions, e.g., moni o ing, eg-
ula ion, and esea ch.
in oduced: see in oduc ion.
in oduc ion: he mo emen o an alien species (ei he
acciden ally, in en ionally and legally, o in en ionally
and illegally) by human ac i i y o a egion ou side i s
na i e ange. In oduc ions can also e e o species ha
we e in oduced o one coun y by humans and sp ead
na u ally o neighbou ing coun ies. In he con ex o in-
oduc ions, he e m ‘acciden al’ is p e e ed o he syn-
onymous e m ‘unin en ional’.
in oduc ion pa hway p ominence: an indica o used
o assess he s a us o in oduc ion pa hways. The in-
dica o assesses he in oduc ion oppo uni ies ha a e
a ailable o alien o ganisms o be in oduced o a coun-
y om o he egions. The indica o conside s in oduc-
ion oppo uni ies in e ms o how socioeconomically
ac i e he pa hways a e (e.g., amoun o ballas wa e e-
leased), a he han how many o ganisms a e in oduced
h ough a pa hway.
in asion: see biological in asions.
in asi e alien species: see in asi e species.
in asi e species: alien species ha sus ain sel -
eplacing popula ions o e se e al li e cycles, p oduce
ep oduc i e o sp ing, o en in e y la ge numbe s a
conside able dis ances om he pa en and/o si e o in-
oduc ion, and ha e he po en ial o sp ead o e long
dis ances. In asi e species can be plan s, animals, un-
gi o mic o-o ganisms, and a e ound ac oss he wo ld
h oughou eshwa e , ma ine and e es ial en i on-
men s.
moni o ing: a sys ema ic p ocess o collec ing and an-
alysing in o ma ion o ack p og ess owa ds eaching
s a ed goals ha acili a es he assessmen o he e ica-
cy o in e en ions.
na i e-alien popula ions (syn. ex alimi al; c . alien
species, na i e species): a popula ion o a axon ha is
na i e o a pa o Sou h A ica, bu ha was ounded by
indi iduals mo ed by di ec human agency, o e a bio-
geog aphical ba ie , o an a ea beyond he species’ na-
i e ange (i.e., i can be conside ed a biological in asions)
(see Box 2.1). This does no include na i e species ha
ha e ex ended hei dis ibu ion by na u al dispe sal.
na i e species (syn. indigenous species, c . alien spe-
cies, na i e-alien popula ion): species ha a e ound
wi hin hei na u al ange whe e hey ha e e ol ed
wi hou human in e en ion (in en ional o acciden al).
Also includes species ha ha e expanded hei ange as
a esul o human modi ica ion o he en i onmen ha
does no di ec ly impac dispe sal (e.g., popula ions a e
s ill conside ed na i e i hey esul om an inc ease in
ange as a esul o wa e ed ga dens, bu a e conside ed
alien i hey esul om an inc ease in ange as a esul o
sp ead along human-c ea ed co ido s linking p e ious-
ly sepa a e biogeog aphic egions).
na u alised (syn. es ablished): alien species ha sus-
ain sel - eplacing popula ions o se e al li e cycles o
o e a gi en pe iod o ime wi hou di ec in e en ion
by people o despi e human in e en ion.
na u al dispe sal (syn. unaided): he dispe sal o an
alien species h ough na u al sp ead om a egion
whe e i was p e iously in oduced h ough di ec hu-
man agency o ano he egion whe e i is no na i e.
Includes bo h sel -p opelled mo emen and mo emen
wi h na u al bio ic (e.g., bi ds) and abio ic (e.g., wind o
wa e ) ec o s.
pa hway (c . ec o ): a b oadly de ined e m ha e e s
o he combina ion o p ocesses and oppo uni ies ha
esul in he mo emen o alien species om one place
o ano he . Includes he cause o eason why he o gan-
ism is anspo ed, he ou e along which i is anspo -
ed and he ec o ha ca ies he o ganism.
x
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
pe mi : an o icial documen issued in e ms o Chap e
7 o he NEM:BA.
pes : an o ganism ha causes nega i e impac s. The a -
ec ed sec o migh be speci ied, so an ag icul u al pes
will impac nega i ely on ag icul u al p oduc ion. Pes s
can be alien o na i e species, and a e usually aken o
e e o animals, wi h pes plan s o en a he e e ed o
as weeds and pes ungi o mic obes e e ed o as dis-
eases o pa hogens.
policy: a high-le el o e all plan, adop ed by he Ex-
ecu i e Au ho i y, o achie ing iden i ied ou comes
h ough speci ied me hods o p inciples ha guide
decision-making. A policy on biological in asions
would be a high-le el plan, which iden i ies goals con-
ce ning biological in asions in Sou h A ica and iden-
i ies he in e en ions ha should be used o achie e
hose goals.
egula ion: 1) a law o ule made by he Execu i e Au-
ho i y in e ms o o iginal legisla ion o egula e con-
duc (in his case he NEM:BA A&IS Regula ions); 2)
he ac o egula ing, i.e., o go e n o di ec acco ding
o ule, o o make egula ions (au ho i a i e ules) o
ce ain conduc .
elease (c . escape): he in en ional in oduc ion o an
alien species o a si e ou side o cap i i y o cul i a-
ion. This e e s o bo h legal and illegal in oduc ions,
howe e i a legally in oduced alien species is illegally
eleased ou side o cap i i y o cul i a ion hen i is clas-
si ied as an escape.
e u ns on in es men : he amoun o alue ha is
gained as a esul o a pa icula amoun spen on an
in e en ion. This can be calcula ed as a bene i : cos
a io whe eby each and spen ( he cos ) is se agains
he amoun o ands gained (bene i ). An in e en ion is
echnically cos -e ec i e i he bene i :cos a io is g ea -
e han one, al hough mo e gene ally cos e ec i eness
is abou maximising he a io.
isk: he likelihood and consequence o an e en , in his
epo he e en is a biological in asion.
isk analysis: he p ocess o iden i ying and assessing
he likelihood and consequence o an e en (i.e., isk as-
sessmen ), as well as conside a ions as o how o man-
age and communica e he isk.
isk assessmen : a componen o isk analysis ha o-
cuses on e alua ing he likelihood and consequence o
an e en aking place. In he con ex o his epo , such
an e en is he likelihood o an alien species becom-
ing an in asi e species and he nega i e impac s ha
would esul . No e in he 2020 NEM:BA A&IS Regula-
ions he e m isk assessmen is used as a synonym o
isk analysis, i.e., isk managemen conside a ions a e
included.
si e: a de ined spa ial a ea, o example a p o ec ed a ea
(as de ined by he Na ional En i onmen al Manage-
men : P o ec ed A eas Ac , 2003); o an adminis a i e
uni (wi h na ional and p o incial adminis a i e bound-
a ies as de ined by he Cons i u ion o he Republic o
Sou h A ica, 1996).
sp ead: see dispe sal
s a us: he s a e, condi ion o s age o a ai s a a pa ic-
ula ime.
s owaway: he acciden al in oduc ion o an alien
species a ached o o wi hin a anspo ec o o hei
associa ed equipmen and media. The o ganism is ans-
po ed by chance, and he e is no speci ic, na u al asso-
cia ion wi h he ec o .
s a egy: a high-le el plan o achie ing managemen
goals in a speci ic ime ame unde condi ions o unce -
ain y.
axon (pl. axa): a g oup o o ganisms ha all sha e
pa icula p ope ies (usually e olu iona y his o y). The
g ouping can be below, a , o abo e he species le el.
h ea : he nega i e impac s ha may occu i an e en
happens (c . isk whe e he likelihood is explici ).
unaided: see na u al dispe sal.
un egula ed in oduc ion: an in oduc ion ha was
no app o ed by he ele an Sou h A ican au ho i ies
unde he ele an egula ions p io o he da e a which
i a i ed in he coun y.
ec o (c . pa hway): he physical means o agen ha
anspo s he alien species. Can be bo h human medi-
a ed (e.g., ballas wa e , clo hing, animal eed o land e-
hicles) o na u al (e.g., wind, wa e , bi ds).
Wa e Managemen A ea: an a ea es ablished as a
managemen uni in he na ional wa e esou ce s a e-
gy wi hin which a ca chmen managemen agency con-
duc s he p o ec ion, use, de elopmen , conse a ion,
managemen and con ol o wa e esou ces.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
x i
Solanum sea o hianum (© Don McCulley).
Biological in asions a e a majo h ea o Sou h A ica’s
wa e secu i y, exace ba e i es, h ea en sus ainable
ag icul u e, and a e ha ing ongoing majo nega i e im-
pac s on Sou h A ica’s unique and globally impo an
biodi e si y. This phenomenon is no unique o Sou h
A ica o o any one pa o he coun y, and hus ad-
d essing biological in asions equi es in eg a ed go -
e nance om in e na ional o local le els. O immedia e
conce n, howe e , is ha he numbe o alien species is
inc easing, he a ea in aded is g owing, bu Sou h A i-
ca’s esponse has been declining.
These issues a e add essed in de ail in his epo The s a us
o biological in asions and hei managemen in Sou h A ica
in 2022. The key messages om his epo a e summa ised
he e in he o m o a single headline ollowed by explana o-
y ex wi h c oss- e e ences (in cu ly b acke s) o he ele-
an sec ions o he epo . Each s a emen is also asc ibed
one o ou con idence le els (inconclusi e, un esol ed,
es ablished bu incomple e and well es ablished) as pe he
guidelines o he In e go e nmen al Science-Policy Pla -
o m on Biodi e si y and Ecosys em Se ices (IPBES) (see
he In oduc ion Chap e o u he de ails).
The messages a e g ouped a ound i e hemes wi h
co esponding indica o s o each heme: A) how alien
species a e in oduced and mo e a ound he coun y
(‘pa hways’); B) he s a us and impac s o alien species
(‘species’); C) how si es a e in aded and impac ed (‘si es’);
D) wha has been done o add ess he p oblem (‘in e -
en ions’); and E) he s a us and managemen o in a-
sions on he P ince Edwa d Islands (PEIs), Sou h A ica’s
sub-An a c ic e i o ies. These messages a e speci ically
in ended o help gauge p og ess wi h managemen and
ad ise hose asked wi h de eloping policy esponses,
hough he messages should also p o ide use ul gene al
insigh s o all hose in e es ed and a ec ed by biological
in asions.
Summa y o key messages1
1This summa y o key-messages is p oduced as pa o ul illing SANBI’s manda e unde he NEM:BA (Ac 10 o 2004) and i s A&IS Regula ions o 2020
o submi a epo on he s a us o in asi e species and he e ec i eness o measu es o comba hem o he Minis e o Fo es y, Fishe ies and he
En i onmen e e y h ee yea s. This is he hi d such epo and p esen s an upda e on issues iden i ied in he i s and second epo s. This summa y
will be a ailable bo h as a s and-alone documen and as pa o he ull epo . Fo ci a ions o his summa y please ci e he ull epo : SANBI and CIB
2023. The s a us o biological in asions and hei managemen in Sou h A ica in 2022. Sou h A ican Na ional Biodi e si y Ins i u e, Ki s enbosch and
DSI-NRF Cen e o Excellence o In asion Biology, S ellenbosch. pp. 122. h p://dx.doi.o g/10.5281/zenodo.8217182.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table o key messages
A1: New alien species con inue o a i e in Sou h A ica e e y yea h ough se e al di -
e en pa hways.
A2: Na i e and alien species a e sp ead by humans a ound Sou h A ica.
A3: In en ional legal in oduc ions a e well egula ed; he new Na ional Bo de Man-
agemen Au ho i y p omises o imp o e he p e en ion o illegal and acciden al
in oduc ions.
B1: The p ocess o documen ing alien species in he coun y has been subs an ially
imp o ed and is now anspa en ; his will acili a e managemen and egula o y
decisions.
B2: Knowledge o he dis ibu ion o alien species has been imp o ed by ci izen sci-
ence and he digi isa ion o his o ical eco ds; s uc u ed su eillance emains es-
sen ial o in o m managemen and ack ends.
B3: In asi e species, in pa icula ees and eshwa e ishes, ha e ‘Majo ’ nega i e im-
pac s on people and na u e ac oss he coun y.
C1: In asions a e dis ibu ed ac oss he coun y including in p o ec ed a eas.
C2: The impac o in asions on wa e esou ces, angeland p oduc i i y and biodi e -
si y a e se e e; imp o ed wo k lows o ack hese impac s a e i al o p io i ising
in e en ions.
D1: The Sou h A ican go e nmen in es ed o e 1.5 billion Rand o add ess biologi-
cal in asions 2020–2022; al hough his in es men has declined ecen ly, he e a e
se e al majo p i a ely unded ini ia i es.
D2: Sou h A ica has an inno a i e egula o y sys em o add ess biological in asions;
his has been e ised and decisions a e now mo e di ec ly in o med by he a ail-
able scien i ic e idence.
D3: Biological in asions ha e been success ully managed in some cases, pa icula ly
h ough biological con ol; planning and moni o ing is needed o hese successes
o be eplica ed.
D4: Wi h judicious in es men and in eg a ed go e nance he impac o in asions on
Sou h A ican socie y can be educed.
E1: In asi e species a e de as a ing he unique and sensi i e biodi e si y o he P ince
Edwa d Islands.
E2: Biological in asions a e being add essed h ough e ec i e biosecu i y and on-is-
land managemen . These p ocesses could be s eng hened by ocussing on egu-
la ions and planning speci ic o he P ince Edwa d Islands.
E3: Bold plans o e adica e he house mouse p omise o sa e Ma ion Island’s seabi ds.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Robinia pseudoacacia (© Agnieszka Kwiecień).
x iii
xix
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A) How alien species a e in oduced
and mo e a ound he coun y
Head-line indica o T end Con idence No es
1. Ra e o in oduc ion
o new un egula ed
species
→low O e he las decade (2013–
2022) app oxima ely h ee
new axa we e in oduced
pe yea ei he acciden ally o
in en ionally bu illegally. This is
simila o p e ious es ima es.
Indica o T end Con idence
1.1 In oduc ion pa hway p ominence →medium
1.2 In oduc ion a es →low
1.3 Wi hin-coun y pa hway p ominence no assessed
1.4 Wi hin-coun y dispe sal a es no assessed
→ no change; ↗ an inc ease; ↘ a dec ease.
A1: New alien species con inue o a i e e e y yea in Sou h
A ica h ough se e al di e en pa hways
New alien species con inue o a i e e e y yea in Sou h A ica (well es ablished) {1.1, 1.2},
wi h he a e o hei in oduc ion emaining s able a a ound h ee species pe yea (es-
ablished bu incomple e) {1.1, 1.2}. These species ha e been in oduced in a ious ways
including acciden ally as con aminan s o nu se y ma e ial, o ho icul u e, and h ough
a igh ly egula ed p ocess o classical biological con ol (es ablished bu incomple e)
{1.2}. While biocon ol agen s ha e o en signi ican ly educed he nega i e impac s o
in asions (well es ablished) {4.8}, o he new alien species a e adding o he ange, com-
plexi y and in ensi y o he nega i e impac s caused (es ablished bu incomple e) {2}. Fo
example, he ungus Sei idium neocup essi, which causes he disease cyp ess canke , was
i s eco ded in Sou h A ica in 2021 on na i e ees [Widd ing onia nodi lo a (moun ain
cyp ess)] (well es ablished) {1.2}. The oppo uni ies o in asi e species o a i e a e ex-
pec ed o inc ease as he olume o ade and a el inc eases; app op ia e biosecu i y
can ensu e such ade is sus ainable.
A2: Na i e and alien species a e sp ead by humans a ound Sou h A ica
Alien species a e being mo ed a ound he coun y (well es ablished) {1.3, 1.4}. Fo exam-
ple, species ha e been in oduced o p o ec ed a eas acciden ally on isi o s’ shoes and
ehicles (es ablished bu incomple e) {1.4}. Na i e species a e also being mo ed and in o-
duced o pa s o he coun y whe e hey a e no na i e (well es ablished) {1.4, Box 2.1}.
A leas 77 na i e species ha e o med 132 na i e-alien popula ions (es ablished bu in-
comple e) {1.4, Box 2.1}. Mos o hese na i e-alien popula ions a e o namen al plan s and
mammals in oduced o game a ms, bu acciden al in oduc ions a e also occu ing, pa -
icula ly wi h anspo ed plan s and hei p oduc s (es ablished bu incomple e) {1.4}. P e-
en ing bo h na i e-alien popula ions and he u he sp ead o exis ing alien species will
equi e a g ea e ocus on acking and managing species mo emen s wi hin he coun y.
xx
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A3: In en ional legal in oduc ions a e well egula ed; he new na ional Bo de Managemen
Au ho i y p omises o imp o e he p e en ion o illegal and acciden al in oduc ions
All legal in oduc ions o new alien axa equi e impo pe mi s, wi h pe mi s issued only i he isks a e demons a ed
o be su icien ly low (well es ablished) {4.1}. Illegal and acciden al in oduc ions a e, howe e , con inuing (es ablished
bu incomple e) {1.2}. Fo example, phy osani a y inspec ions o ag icul u al goods egula ly in e cep alien species
no known o be p esen in he coun y {4.7}. T ade and a el con ols pu in place o p e en he sp ead o COVID-19
caused a empo a y decline in in oduc ion oppo uni ies, bu hese a e e u ning o p e-pandemic le els (es ablished
bu incomple e) {1.1}. A majo de elopmen o imp o e he in eg a ed go e nance o Sou h A ica’s biosecu i y was he
es ablishmen o he na ional Bo de Managemen Au ho i y (BMA) in 2020, ha became ully ope a ional in 2023. The
BMA p omises o imp o e he p e en ion o illegal and acciden al in oduc ions.
Sou h A ica’s 72 o icial po s o en y (see Sec ion S1.3).
xxi
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
B) The s a us and impac s o alien species
Head-line indica o T end Con idence No es
2. Numbe o in asi e
species ha ha e
‘Majo ’ impac s
↗low
(many
axa s ill
need o be
assessed)
The impac o 36 in asi e
species has been assessed
using he me hodology o he
IUCN’s EICAT scheme. O hese,
19 a e epo ed o cause ‘Majo ’
o ‘Massi e’ impac s in mainland
Sou h A ica.
Indica o T end Con idence
2.1 Numbe and s a us o alien species ↗high
2.2 Ex en o alien species →medium
2.3 Abundance o alien species no assessed
2.4 Impac o alien species ↗medium
→ no change; ↗ an inc ease; ↘ a dec ease.
B1: The p ocess o documen ing alien species in he coun y has
been subs an ially imp o ed and is now anspa en ; his
will acili a e managemen and egula o y decisions
The e has been signi ican p og ess in colla ing a lis o alien species in he coun y, wi h
in o ma ion, whe e a ailable, on hei dis ibu ions, impac s and managemen (es ab-
lished bu incomple e) {2, 4.1, 4.5, 4.8}. The de elopmen o documen ed and epea able
wo k lows ensu es i is clea why species a e included on he lis and acili a es upda es
o he lis (es ablished bu incomple e) {Appendix 4}. To da e he lis includes eco ds o
o e 3500 alien species p esen ou side o cap i i y o cul i a ion in Sou h A ica, a leas
a hi d o which a e eco ded as in asi e (es ablished bu incomple e) {2.1}. As da a a e
cap u ed and colla ed hese numbe s will inc ease: key sou ces s ill need o be e i ied
and in eg a ed in o he lis (pa icula ly species in cul i a ion); and many alien species
a e ye o be de ec ed and documen ed. A comp ehensi e lis will acili a e acking he
numbe and s a us o alien species o e ime, eeding in o managemen planning and
acili a ing egula o y decisions.
B2: Knowledge o he dis ibu ion o alien species has been imp o ed by
ci izen science and he digi isa ion o his o ical eco ds; s uc u ed
su eillance emains essen ial o in o m managemen and ack ends
Ci izen science pla o ms ha e inc eased knowledge o he dis ibu ion o some alien
species and inc eased communi y engagemen wi h issues a ound in asi e species (es-
ablished bu incomple e) {2.2}. The digi isa ion o his o ical eco ds, o example h ough
he Na ional Collec ions Facili y and by he F eshwa e Biodi e si y In o ma ion Sys em,
means ha ield obse a ions and eco ds o physical specimens can be accessed h ough
na ional and in e na ional da abases (well es ablished) {2.1}. A hia us in he Sou he n A -
ican Plan In ade s A las (SAPIA) has inhibi ed he abili y o ack plan in asions ac oss
Sou h A ica. Ensu ing he long- e m sus ainabili y o s uc u ed su eillance e o s and
xxii
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
in eg a ing hese wi h his o ical da a and ci izen science obse a ions will suppo managemen planning and acili-
a e egula o y decisions.
B3: In asi e species, in pa icula ees and eshwa e ishes, ha e ‘Majo ’
nega i e impac s on people and na u e ac oss he coun y
The nega i e impac s o in asi e species on biodi e si y and people’s li elihoods a e known o be subs an ial (es ab-
lished bu incomple e) {2.4}. Ele en (11) ee o sh ub species, i e ish species, wo g ass species and one in e eb a e
species ha e been assessed o cause ‘Majo ’ o ‘Massi e’ nega i e impac s a a na ional le el (es ablished bu incom-
ple e) {2.4}. This numbe is based on 36 assessmen s using he IUCN’s En i onmen al Impac Classi ica ion o Alien Taxa
(EICAT) me hodology. The need o mo e s udies and assessmen s on he impac o in asi e species has been high-
ligh ed as a esea ch p io i y o Sou h A ica. The de elopmen and implemen a ion o coun y-le el species-speci ic
managemen s a egies in o med by impac assessmen s would help p o ec biodi e si y and ensu e ha ecosys em
se ices essen ial o human wellbeing a e main ained.
Examples o alien species wi h ‘Majo ’ impac s in Sou h A ica (see Sec ion 2.4). Pho og aphs ( om le o igh ): Acacia saligna (©
Suzaan K i zinge -Kloppe ); Lan ana cama a (© Juan Ca los Fonseca Ma a); Mic op e us salmoides (© Ma nus E asmus).
xxiii
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
C) How si es a e in aded and impac ed
Head-line indica o T end Con idence No es
3. Ex en o a ea
ha su e s
‘Majo ’ impac s
om in asions
no eassessed Biological in asions con inue
o cause majo impac s on
biodi e si y, ecosys em
se ices and human li elihoods
by educing Sou h A ica’s
wa e esou ces, deg ading
pas u elands and exace ba ing
i es. These es ima es,
howe e , need o be upda ed
and egula ly e ised.
Ongoing wo k includes he
de elopmen o sys ema ic
p ocesses o e alua ing
impac s udies and wo k lows
ha link o o he biodi e si y
assessmen s and p e ious
s udies.
Indica o T end Con idence
3.1 Alien species ichness ↗low
3.2 Rela i e in asi e abundance →low
3.3 Impac o in asions no eassessed
→ no change; ↗ an inc ease; ↘ a dec ease.
C1: In asions a e dis ibu ed ac oss he coun y including in p o ec ed a eas
In asi e species a e dis ibu ed ac oss he coun y, wi h mos b oad-scale adminis a-
i e uni s and biogeog aphical egions being in aded by a a ie y o axa (es ablished
bu incomple e) {3.1}. Mos alien species a e ound in he Wes e n Cape, Eas e n Cape,
and KwaZulu-Na al (es ablished bu incomple e) {3.1}, and a ound majo u ban cen es
(es ablished bu incomple e) {3.1}. This is likely because some species a e commensal wi h
humans, mos we e i s in oduced o u ban cen es, and because o g ea e sampling
a ound u ban a eas (in pa icula he e has been a apid, ecen inc ease in obse a ions
om ci izen scien is pla o ms such iNa u alis ) (es ablished bu incomple e) {3.1}. Robus
and eliable moni o ing sys ems ha consis en ly ack he dis ibu ion and abundance
o alien species ac oss he coun y a e, howe e , lacking. This means ha he ex en o
in asions and he e ec i eness o in e en ions canno be assessed wi h a high deg ee
o ce ain y. Da a on he dis ibu ion and abundance o alien species need o be col-
lec ed, colla ed and in eg a ed in o na ional and global da abases o acili a e he plan-
ning o in e en ions. All p o ec ed a ea complexes a e in aded o some deg ee (well
es ablished) {3.1}, wi h es ima es o ela i e in asi e abundance anging om mino o
ex ensi e (no la ge ecen changes ha e been no ed) (es ablished bu incomple e) {3.1}.
O e 700 in asi e e es ial and eshwa e species (excluding biological con ol agen s)
a e epo ed o occu ac oss p o ec ed a eas managed by SANPa ks and CapeNa u e
(well es ablished) {3.1}, wi h a ew p o ec ed a eas epo ing pa icula ly high numbe s o
in asi e species (well es ablished) {3.2}.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Eucalyp us g andis (© John Robe McPhe son).
1
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
The signi icance o biological in asions o Sou h A ica
Biological in asions a e amongs he leading causes o global change – hey ha e had p o ound nega i e impac s on
people and na u e o cen u ies; a e cu en ly a signi ican d ain on Sou h A ica’s sus ainable de elopmen and a e
nega i ely impac ing na i e biodi e si y; and pose a majo h ea o bo h he quali y o li e o u u e gene a ions and
he globally unique lo a and auna ha a e an in eg al pa o his coun y (Pyšek e al. 2020; Van Wilgen e al. 2020).
The p oblem is complica ed and se o g ow (Chap e s 1 and 6). In asi e species come om many di e en axa, in ade
di e en habi a s, and cause a ious ypes o impac s, some imes in ways which a e no ye ully unde s ood bu ha
will ha e p o ound e ec s on he abili y o ecosys ems o deli e se ices o people (Chap e s 3, 4 and 6; Van Wilgen e
al. 2020).
Thank ully, signi ican p og ess has been made in educing impac s and p e en ing new in asions (Chap e 4). Ta ge -
ed in e en ions can be highly cos -e ec i e, and so, whils in e en ions can be complica ed and cos ly, by wo king
oge he as a socie y we can p o ec ou biodi e si y and na u al capi al om biological in asions. The na u e o he
impac s and he ypes o esponses needed means ha biological in asions a e a signi ican c oss-cu ing issue o
Sou h A ica ha is managed by a ange o s akeholde s using a a ie y o app oaches.
Sou h A ica’s egula o y amewo k ega ding biological
in asions and he speci ic manda e o he hi d s a us epo
The speci ic manda e o he s a us epo o iginally a ose om Sec ion 11 o he Na ional En i onmen al Managemen :
Biodi e si y Ac , which s a ed:
11. (1) The Ins i u e1—
(a) mus moni o and epo egula ly o he Minis e on-...
(iii) he s a us o all lis ed in asi e species;
This equi emen was elabo a ed in he Alien and In asi e Species Regula ions (NEM:BA A&IS Regula ions) ha we e
published on 1 Augus 2014 and p omulga ed in Oc obe 2014. Re ised egula ions we e published on 18 Sep embe
2020 and p omulga ed on 1 Ma ch 2021, wi h Sec ion 13 s a ing:
13. (1) The Ins i u e o a body designa ed by he Ins i u e mus , o he pu pose o epo ing as con empla ed in sec ion
11(1)(a)(iii) o he Ac , submi a epo on he s a us o lis ed in asi e species o he Minis e wi hin h ee yea s o he
da e on which hese egula ions come in o e ec , and a leas e e y h ee yea s he ea e 2.
(2) A epo con empla ed in sub- egula ion (1) mus con ain a summa y and assessmen o —
(a) he s a us o lis ed in asi e species and o he species ha ha e been subjec ed o a isk assessmen ; and
In oduc ion
Au ho s: John R. Wilson & Tsungai A. Zengeya
1 The Sou h A ican Na ional Biodi e si y Ins i u e (SANBI).
2Technically his epo is due Ma ch 2024, al hough in keeping wi h a h ee-yea cycle, he epo was p oduced by Oc obe 2023.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
(b) he e ec i eness o hese egula ions and con ol measu es based in e alia on in o ma ion om—
(i) no i ica ions ecei ed om owne s o land ega ding lis ed in asi e species occu ing on hei land;
(ii) pe mi s issued o lis ed in asi e species;
(iii) In asi e Species Moni o ing, Con ol and E adica ion Plans ecei ed om o gans o s a e and managemen
au ho i ies o p o ec ed a eas; and
(i ) eme gency in e en ions and en o cemen ac ions in ol ing lis ed in asi e species.
(3) In p epa ing a epo con empla ed in sub- egula ion (1), he Ins i u e mus ca y ou he esea ch and moni o ing
necessa y o iden i y he ma e s con empla ed in sub- egula ion (2).
The ‘in asi e species’ e e ed o in he Ac and he Regula ions a e hose ha appea on a lis o axa published in he
Go e nmen Gaze e. These axa a e egula ed in se e al di e en ways [see Wilson (2023) o he ull lis s]. The 2020
NEM:BA A&IS Lis s ( ha came in o e ec Ma ch 2021) lis ed 560 alid axa, as well as all hyb ids be ween na i e and
alien species o amphibians, bi ds, mammals and ep iles. In p e ious e sions o he lis s a u he 562 axa had been
lis ed, many o hese p e iously lis ed axa we e lis ed as ‘p ohibi ed’ wi h he implica ion ha hey a e no cu en ly
p esen in he coun y; he lis o p ohibi ed axa was emo ed and no included in he 2020 lis s (see Sec ion 4.1). A
u he 153 ha e been p oposed o lis ing. Fo he ull lis s see Wilson (2023). A hand ul o addi ional axa ha e had
‘ isk assessmen s’ conduc ed on hem bu a e no cu en ly o his o ically lis ed. These lis s o med he s a ing poin
o his and p e ious epo s; howe e , p oducing a epo based simply on hese axa would no comple ely ul il he
manda e, no add ess he b oade issue o biological in asions.
The b oade manda e, pu pose and
s uc u e o he hi d s a us epo
The issue o biological in asions has ecei ed signi ican ecen global a en ion in pa icula wi h he p oduc ion and
elease in Oc obe 2023 o he In e go e nmen al Science-Policy Pla o m on Biodi e si y and Ecosys em Se ices (IP-
BES)’s Thema ic Assessmen Repo on In asi e Alien Species and hei Con ol (Box 0.1); and he Kunming-Mon eal Global
Biodi e si y F amewo k (GBF) ha was ag eed unde he Con en ion on Biological Di e si y (CBD) in Decembe 2022
(Box 0.2). This hi d s a us epo si s i mly wi hin his con ex . The s a us epo aims o s eng hen he links be ween
basic esea ch, policy and managemen , by p o iding suppo o decision make s ha is policy ele an bu no policy
p esc ip i e (Figu e S0.1).
Sagi a ia la i olia (© Michel Gaube ).
2
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
The i s epo was p oduced in 2017 and eleased in 2018, and he second p oduced in 2020 and eleased in 2021.
Bo h we e s uc u ed a ound an indica o amewo k ha explici ly conside s biological in asions in e ms o pa hways,
species, si es and in e en ions (wi h indica o s on in e en ions di ided in o hose conside ing inpu s, ou pu s and
ou comes). This indica o amewo k p o ides a anspa en and objec i e me hod o he es ablishmen o a baseline
agains which o assess ends, se ealis ic managemen a ge s, and o highligh ing impo an gaps in he e idence
needed o suppo decision-making. This hi d epo ou lines ends o e he pas h ee yea s o he ou headline
indica o s and o he 20 indica o s acking pa hways, species, si es and in e en ions. I akes ime o compile, e ise
and p oduce hese epo s. The e o e, a cu -o da e is needed, a e which no new da a a e conside ed. This hi d epo
is hus en i led The s a us o biological in asions and hei managemen in Sou h A ica in 2022, as i epo s on he s a us
up o he end o 2022, al hough was inalised by Oc obe 2023 and eleased ea ly in 2024. None heless key e en s ha
happened in 2023 (e.g., Box 0.1) a e acknowledged.
The epo comp ises chap e s based on he amewo k (i.e., on pa hways, species, si es and in e en ions). Each
chap e s a s wi h a summa y o he indings, and hen a discussion o key changes o he indica o s and ecen
no ewo hy e en s, wi h impo an case s udies in he o m o ex boxes. In addi ion, o his epo , a chap e -leng h
case s udy is p o ided on ‘The s a us o biological in asions and hei managemen in he P ince Edwa d Islands’. The
P ince Edwa d Islands (Ma ion Island and P ince Edwa d Island) lie in he Sou he n Ocean, 1400km om con inen al
Sou h A ica, and a e dis inc om he mainland bo h in e ms o he na u e o biological in asions and how hey a e
managed. A inal chap e e alua es he deg ee o which gaps iden i ied in he p e ious epo s ha e been illed, looks
a addi ional key gaps ha need o be add essed in u u e epo s, and iden i ies ecommenda ions ele an o how
Sou h A ica unde s ands and manages biological in asions. Much o he de ail unde lying he p oduc ion o he
epo is con ained wi hin he appendices and supplemen a y ma e ial a ailable online (see p. 122 o links o hese
documen s).
A ocus o his epo is o p oduce wo k lows and ensu e da a a e FAIR1 and idy2 in line wi h in e na ional bes p ac ice
(IPBES 2018). In so doing, he epo p ocess should be mo e sus ainable in ha he p ocesses used a e documen ed
and can be epea ed. The longe - e m plan is o de elop an online esou ce wi h indica o alues upda ed as soon as
new in o ma ion becomes a ailable (i.e., a dashboa d) ha can be used o p oduce epo s on demand, and o m he
basis bo h o semi-au oma ed annual epo s and less equen comp ehensi e epo s (see Sec ion S.0.2, no ing ha
such plans will need o be compa ible wi h egula o y equi emen s – cu en ly iennial epo s a e manda ed). The
in en ion o his epo is hus o p o ide an upda e o he second epo , and ocus on he p ocess, ecognising ha all
iden i ied da a sou ces ha e no ye been inco po a ed (e.g., see Table S2.1 o a lis o sou ces ha ha e o need o be
inco po a ed in he lis o alien axa).
T achemys sc ip a subsp. elegans (© Johannes Maximilian).
3
1Findable, Accessible, In e ope able and Reusable: www.go- ai .o g/.
2As de ined by Wickham (2014), see Sec ion S0.4 o mo e de ails.
4
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
The ‘Summa y o key messages’ and
communica ing he deg ee o con idence
The epo begins wi h a summa y o key messages. This is o ma ed so ha i can be p oduced and p in ed as a
s and-alone documen . The key messages om his epo a e summa ised in he o m o a single headline ollowed
by explana o y ex wi h c oss- e e ences o he ele an sec ions o he epo . Each s a emen is also asc ibed one
o ou con idence le els as pe he guidelines o he In e go e nmen al Science-Policy Pla o m on Biodi e si y and
Ecosys em Se ices (IPBES; Figu e 0.1).
Figu e 0 .1 . The In e go e nmen al Science-Policy Pla o m on Biodi e si y and Ecosys em Se ices (IPBES)’s ou -box model o
quan i a i e communica ion o con idence. Con idence inc eases owa ds he op- igh co ne , as sugges ed by he inc easing
s eng h o shading (IPBES 2018). Well es ablished: he e is a comp ehensi e me a-analysis o o he syn hesis o mul iple inde-
penden s udies ha ag ee; Es ablished bu incomple e: he e is gene al ag eemen , al hough only a limi ed numbe o s udies
exis , he e is no comp ehensi e syn hesis and/o he s udies ha exis add ess he ques ion imp ecisely; Un esol ed: mul iple
independen s udies exis bu hei conclusions do no ag ee; and Inconclusi e: he e is limi ed e idence and a ecogni ion o
majo knowledge gaps.
low
high
Es ablished bu incomple e Well es ablished
Inconclusi e Un esol ed
low
high
obus
Ce ain y scale
Le el o ag eemen
Quan i y and quali y o e idence
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Schinus molle (© SAplan s).
5
6
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
P ocess o he compila ion o he epo
The p ocess was b oadly simila o he i s wo epo s (Figu e 0.2), wi h la gely he same eam, consis ing o he Sou h
A ican Na ional Biodi e si y Ins i u e as he lead ins i u e, he Cen e o In asion Biology as a collabo a ing pa ne ,
and a ious manage s, esea che s, p i a e indi iduals and ins i u ions p o iding in o ma ion and commen s on d a
epo s.
Re iew o elease o he second epo and essen ial wo k lows iden i ied: The SANBI-CIB d a ing eam e lec ed on he
epo launch and how he epo was ecei ed, and in pa icula iden i ied he need o close engagemen wi h a ec -
ed go e nmen depa men s. In pa icula , i was no ed ha by p o iding an oppo uni y o e alua e he indings and
de elop app op ia e esponses ahead o he epo launch, a ec ed agencies would be in a be e posi ion o espond
o and up ake he indings. The d a ing eam also iden i ied essen ial wo k lows o he p oduc ion o he epo ha
needed o be se up du ing his epo cycle.
Appoin a e e ence and ad iso y commi ee (RAC): a RAC was es ablished o p o ide o e sigh o he p ocess and e iew
documen s p oduced. The i s mee ing o he RAC was on 22 Feb ua y 2022 a which a p oposed able o con en s was
app o ed. A d a o he epo was sen o he RAC on 9 Sep embe 2022, and discussed a he second mee ing o he
RAC on 28 Sep embe 2022. The epo was e ised and sen ou o public commen on 20 Decembe 2022. The second
d a o public commen was sen o he RAC a he same ime as i was made public, and a mee ing held on 26 June
2023. The Chai o he RAC also e iewed how he commen s ecei ed du ing all ounds o e iew we e add essed, i.e.,
ac ed in a e iew edi o ole. Finally, he RAC p o ided ad ice bo h in e ms o he public elease o he epo and on
e lec ing on he p ocess.
Colla e and e iew a ailable in o ma ion: In o ma ion was inco po a ed in o he epo p ima ily om published li e -
a u e and unpublished in o ma ion p o ided by s akeholde s. In o ma ion con ained in he epo is based on da a
a ailable o he epo w i ing eam as o he end o Decembe 2022 (see Supplemen a y Ma e ial o each chap e ).
S akeholde engagemen : Du ing epo p oduc ion, s akeholde engagemen was an ongoing p ocess linked o he
o he ac i i ies. Ini ially he d a ing eam engaged di ec ly wi h specialis con ibu o s o ob ain in o ma ion ha was
no eadily accessible and iden i ied s akeholde s o be con ac ed o inpu and e iew. Con ibu o s we e iden i ied
ini ially based on hose iden i ied p e iously. Those who p o ided commen s we e asked o upda es. New po en ial
con ibu o s we e con ac ed on an ad hoc basis as in o ma ion became a ailable and in esponse o he public con-
sul a ion. Con ibu ions came om academic ins i u ions; esea ch ins i u es and science councils; na ional, p o incial,
and local go e nmen depa men s; and om p i a e indi iduals who we e in e es ed and a ec ed. Con ibu ions
om he iden i ied s akeholde s we e in he o m o da a p o ision and commen ing on d a s.
The epo p ocess is ongoing. The e a e in o ma ion sou ces a ailable ha , gi en cons ain s, could no be ully inco -
po a ed in his hi d epo (in pa icula see Table S2.1 o in o ma ion sou ces ha need o be inco po a ed in o he
species lis ). In cases whe e in o ma ion was belie ed o be a ailable bu was no o hcoming, he lack o in o ma ion is
lagged ei he in he epo o in he Supplemen a y Ma e ial. Finally, some in o ma ion is simply no a ailable. Impo -
an da a ha e ei he no been ga he ed o app op ia ely cu a ed. Fo a discussion on gaps see Chap e 6.
Re iew o d a epo s: A d a was comple ed in Sep embe 2022 and sen o he RAC o in e nal e iew. This was
hen discussed a a mee ing o he RAC on 28 Sep embe 2022, e ised and sen ou o public e iew by expe s and
s akeholde s o a pe iod o 10 weeks (20 Decembe 2022–28 Feb ua y 2022). The eques o e iew was submi ed o
a Sou h A ican lis se e on biological in asions (in asi es@wo dlink.co.za), heads o ele an na ional and p o incial
go e nmen depa men s, heads o ele an academic depa men s and ins i u ions, and p o essional socie ies and o-
ums (including he Royal Socie y o Sou h A ica; he Akademie i We enskap en Kuns; he Zoological, En omological
and Bo anical Socie ies; Bi dli e Sou h A ica; and he Wildli e and En i onmen Socie y o Sou h A ica). A copy o he
i s d a o public commen was a ached o he o mal no ice and was a ailable o download online (h p://dx.doi.
o g/10.5281/zenodo.7414804).
In June 2023, he nex d a o he epo was p oduced and sen o public commen o six weeks using he same con-
ac s as p e iously (20 June 2023–31 July 2023). In addi ion, he epo was sen o one independen expe om Sou h
7
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Figu e 0 .2 . Key s eps in he p oduc ion o he epo The s a us o biological in asions and hei managemen in Sou h A ica in 2022.
The Minis e is he Sou h A ican Minis e o Fo es y, Fishe ies and he En i onmen ; he RAC is he esea ch and ad iso y com-
mi ee; and SANBI is he Sou h A ican Na ional Biodi e si y Ins i u e.
Re e enceandad iso ycommi ee
S akeholde engagemen
S a us epo eam e iew he elease o he second epo and iden i y wo k�ows
needed o he hi d epo (Jun–Dec 2021)
Second s a us epo launched (28 May 2021)
Second s a us epo �nalised (2 No 2020)
Mee ing
(22 Feb 2022)
Re iew d a
Mee ing
(28 Sep 2022)
Re iew o e ision
and esponse o
commen s
Mee ing
(26 Jun 2023)
Check esponses
o commen s
ecei ed
Mee ing
(5 Dec 2023)
D a able o con en s (Feb 2022)
Assign alues o indica o s
P oduce d a epo
(Sep 2022)
Re ised d a o public commen
(Dec 2022–Feb 2023)
Re ise d a a e public commen s
(Feb–Jun 2023)
Re ised d a o public commen
(Jun–Jul 2023)
Final e isions
(Jul–Aug 2023)
Submi o SANBI Boa d (Oc 2023)
Submi o Minis e (Feb 2024)
Public elease
Re�ec on he p ocess
Con e ence and
wo kshop
p esen a ions
S akeholde
e iew
(Dec 2022–
Feb 2023)
Second ound
o s akeholde
e iew &
addi ional
expe e iew
(Jun–Jul 2023)
Engage wi h
go e nmen on
hei esponse
o key �ndings
Media enqui ies
S akeholde
wo kshop
S akeholde
wo kshop
Colla e and
e iew a ailable
in o ma ion
Iden i y and
engage
specialis
con ibu o s
Appoin a
RAC (Jan 2022)
Iden i y
s akeholde s
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A ica, one in e na ional expe and membe s o he RAC. A copy o he second d a o public commen was a ached
o he o mal no ice and was a ailable o download online (h p://dx.doi.o g/10.5281/zenodo.8037187).
Du ing he i s ound o ex e nal public e iew, commen s we e ecei ed om 19 sou ces, ep esen ing en ins i u ions
including he DFFE and he DWS. Du ing he second ound o ex e nal public e iew, commen s we e ecei ed om 13
sou ces, ep esen ing nine ins i u ions (some commen ed in hei p i a e capaci y). All eedback was eco ded and he
commen s esponded o in line wi h in e na ional bes p ac ice (IPBES 2018). The inpu s and esponses o he eques s
o e iew we e documen ed and he esponses we e discussed wi h he RAC (wi h he RAC ac ing in he ole o a e-
iew edi o ). The commen da abase is a ailable o sc u iny om SANBI on eques . On he second ound o e iew,
se e al commen s we e ecei ed a e he deadline o 31 July 2023. These commen s we e cap u ed in a sepa a e da a-
base and, in cases whe e he commen s could no be add essed be o e he epo wen in o p oduc ion, he commen s
will be used o in o m u u e epo s.
P oduce and elease he inal epo : A e add essing he commen s in he inal ound o e iew he epo was edi ed,
and a comple e e sion sen on 20 Sep embe 2023 o he SANBI G aphics eam o copy edi ing, layou , design and
p in ing. In pa allel, a copy o he epo was also submi ed o he SANBI Boa d in Oc obe 2023 o hei conside a ion.
A e boa d app o al, he epo was laid ou and p in ed, and hen he SANBI CEO submi ed he epo o he Minis e
o Fo es y, Fishe ies and he En i onmen . A he same ime a copy o he epo was submi ed o he DFFE and he
DALRRD as he key ecei e s o he epo . This p o ided he depa men s wi h an oppo uni y o p epa e o espond-
ing o media enqui ies o public conce ns aised and o seek cla i ica ion om he epo d a ing eam as needed,
no ing ha no changes could be made o he epo du ing his pe iod sa e o any edi o ial changes made by SANBI
G aphics & Edi ing. As wi h p e ious epo s, in o ma ion will be included in he Sou h A ican S a e o he En i onmen
Repo p ocess (h p://soe .en i onmen .go .za/soe /).
Re lec on he p ocess: A e he public elease o he epo he s a us epo eam will con ene a mee ing wi h key
s akeholde s (including membe s o he RAC) o e lec on he p ocess used o compile he epo and o iden i y a eas
o imp o emen o subsequen epo s (see Chap e 6).
Neph olepis co di olia (© Fo es and Kim S a ).
8
9
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o s
This epo is s uc u ed a ound ou g oups o indica o s (24 in o al) as ou lined in Wilson e al. (2018) (Figu e 0.3) and adhe es b oadly o he published indica o ac -
shee s (a ailable o download a h ps:// inyu l.com/5n6 bymh). Howe e , he e ha e been sligh upda es and co ec ions o how some hings we e sco ed, and he
numbe ing o he indica o s has changed sligh ly o e lec hei hie a chy. As such, he indica o s should be ead in conce wi h he me ada a o he species lis and o he
wo k lows, wi h he mo e ecen documen s aking p ecedence. The echnical de ails on sco ing he indica o s a e a ailable in he Supplemen a y Ma e ial. Fully e ised
and upda ed indica o ac shee s will be p o ided oge he wi h he nex epo .
No ably, he baselines p oposed in p e ious epo s needed o be e ised in some ins ances (e.g., due o e o s in he o iginal alues). This means ha i is no always ap-
p op ia e o compa e alues be ween he epo s, and in some cases he epo calcula ed he alues ha should ha e been in p e ious epo s. Changes o e ime om
hese e ised baselines a e p esen ed and discussed in his epo and di e ences in he calcula ion me hods used be ween he epo s a e no ed in he Supplemen a y
Ma e ial. Indica o s a e highligh ed in bold h oughou he main epo , bu a e in plain ex in he summa y o policy-make s
Figu e 0 .3 . Indica o s used in he epo [based on Wilson e al. (2018)].
1.2 In oduc ion a es
1.1 In oduc ion pa hway p ominence
3.3 Impac o in asions
3.2 Rela i e in asi e abundance
s
n
o
i
n
e
e
n
I
OUTCOMES
4.7 Effec i eness o
pa hway ea men s
OUTPUTS
4.4 Pa hways ea ed
INPUTS
4.8 Effec i eness o
species ea men s
4.1 Quali y o egula o y
amewo k
4.5 Species ea ed 4.2 Money spen
4.9 Effec i eness o si e
ea men s 4.6 Si es ea ed 4.3 Planning co e age
1. Ra e o un egula ed in oduc ion
o new species
2. Numbe o in asi e species ha
ha e 'Majo ' impac s
3. Ex en o a ea ha suffe s 'Majo '
impac s om in asions
4. Le el o success in managing
in asions
2.3 Abundance o alien species
2.2 Ex en o alien species
3.1 Alien species ichness
2.4 Impac o alien species
2.1 Numbe and s a us o alien species
1.4 Wi hin-coun y dispe sal a es
1.3 Wi hin-coun y pa hway p ominence
s
e
i
S
s
y
a
w
h
a
P
16
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o s co e ed in he pa hways chap e
1.2 In oduc ion a es
1.1 In oduc ion pa hway p ominence
1.4 Wi hin-coun y dispe sal a es
1.3 Wi hin-coun y pa hway p ominence
s
y
a
w
h
a
P
Fo all pa hway indica o s, he pa hway classi ica ion amewo k o he Con en ion on Biological Di e si y was used
(CBD 2014). The pa hways a e shown in Figu e 1.1 and de ails on he pa hways, including desc ip ions and de ini ions,
a e p o ided in Ha owe e al. (2018), an open access documen . Speci ic de ails o alues a e p o ided in Appendix 5
and me hodological changes om p e ious epo s and de ails o how he calcula ions we e made a e ou lined in he
Supplemen a y Ma e ial (e.g., Table S1.1).
1.1 In oduc ion pa hway p ominence
In oduc ion pa hway p ominence assesses, based on socio-economic da a, he oppo uni ies a ailable o alien
o ganisms o be in oduced o Sou h A ica om o he coun ies. This indica o does no conside how many in oduc-
ions hese oppo uni ies ha e esul ed in. I e ec i e biosecu i y is in place, hen a la ge o inc easing in oduc ion
pa hway p ominence (e.g., inc easing ood impo s) is no a conce n in e ms o biological in asions.
The e ha e been ew quali a i e changes o in oduc ion pa hway p ominence (Figu e 1.1). One excep ion is he p o-
mo ion o aquacul u e as a ood sou ce (Van De en e e al. 2019), wi h p oduc ion inc easing s eadily o 10500 onnes
by 2021 (an inc ease o 30% om 2016 and 14% om 2019). The in oduc ion pa hway p ominence o his pa hway
has inc eased om ‘Mino ’ o ‘Mode a e’. In oduc ion pa hway p ominence was es ima ed o he i s ime o wo
pa hways – conse a ion and impo s o machine y and ehicles, bo h o which ha e ‘Majo ’ in oduc ion pa hway
p ominence (Figu e 1.1).
The e ha e been quan i a i e changes, wi h mo e han a 10% decline, o e he pe iod 2020–2022, in he in oduc ion
oppo uni ies p o ided by nine o he 44 in oduc ion pa hways. Fo example, he numbe o ai c a a i als om in e -
na ional and egional des ina ions declined by 18%, and he numbe o people en e ing he coun y declined by 47%.
The con ols placed on ade and a el o p e en he sp ead o COVID-19 d o e hese ends. Howe e , hese changes
seem o ha e been empo a y, and a e no la ge enough o cons i u e a quali a i e change in he indica o alue. Fo
example, in he 2019/2020 inancial yea o e 50000 ai c a a i ed om egional and in e na ional des ina ions, and
while in 2020/2021 his numbe declined o ~13000, by 2021/2022 he numbe had inc eased o ~30000, and by
2022/2023 o ~42 000 (Figu e S1.14). The e o e, he numbe o ai c a a i als is e u ning o p e-pandemic le els, and
hus o his pa hway, in oduc ion pa hway p ominence has been ‘Mode a e’ h oughou (Figu e 1.1).
Recen esea ch on he pe ade and medicinal plan ade has con i med he indings epo ed in he second epo
ha bo h pa hways ha e a ‘Mode a e’ in oduc ion pa hway p ominence. The pe ade is di e se (Shi ambu e al.
2022a), wi h ecen esea ch ocussing on alien gas opods (Shi ambu e al. 2020), mammals (Shi ambu e al. 2021),
ep iles (Man in silili e al. 2022), and bi ds (Shi ambu e al. 2022b). Pe s a e aded bo h in physical shops and online,
wi h he as majo i y o he ade in highly popula ed a eas wi h ela i ely la ge economies, such as Gau eng, KwaZu-
lu-Na al and he Wes e n Cape (Shi ambu e al. 2021, 2022b; Man in silili e al. 2022). A consolida ed lis o 475 alien
plan axa used as adi ional medicine in Sou h A ica has ecen ly been published (Williams e al. 2021a). Al hough
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
17
Inc easing human ole
Mechanism o
en y
Pa hway
ca ego y Pa hway subca ego y #
# since
Dec 2019 IPP
IPP since
Dec 2019
Biological con ol 278 ↗Mod →
S abilisa ion & ba ie s 95 ↗Min →
Fishe y in he wild 17 →Mod →
Release Hun ing 34 →Maj →
Aes he ic elease 10 →PNP →
Conse a ion in wild 3 →Maj —
Release o use 9 →? ?
O he elease 0 →? ?
Ag icul u e 113 ↗Maj →
Aquacul u e 15 →Mod ↗
Bo anical ga dens & zoos 5 →Min →
Pe 56 →Mod →
Fa med animals 16 →Maj →
Commodi y Escape Fo es y 39 →Maj →
Fu a ms 1 →Min →
Ho icul u e 301 →Mod →
O namen al 277 ↗Mod →
Resea ch 21 →Min →
Li e ood & li e bai 2 →?→
O he escape 1 →Mod →
Nu se y ma e ial con aminan 14 ↗Mod →
Bai con aminan 15 →?→
Food con aminan 15 →Mod →
Con aminan o animals 9 →Maj →
Pa asi es o animals 36 →Maj →
Con aminan Con aminan o plan s 26 →Mod →
Pa asi es o plan s 30 →Mod →
Seed con aminan 40 →Mod →
Timbe ade con aminan 14 →Maj →
Habi a ma e ial con aminan 6 →?→
Fishing equipmen 0 →Mod →
Con aine & bulk ca go 13 →Maj →
Ai plane 3 →Mod →
Ship 26 →Mod →
Machine y & equipmen 1 →Maj —
T anspo ec o S owaway People & luggage 0 →Maj →
Packing ma e ial 4 →?→
Ballas wa e 62 →Mod →
Hull ouling 79 →Mod →
Land ehicles 1 →Maj →
O he s owaway 2 →?→
Canals & a i icial wa e ways 0 →Min →
Na u al sp ead Tunnels & b idges 0 →Min →
Unaided Na u al dispe sal 15 →Maj →
Figu e 1 .1 . Cu en s a us o he in oduc ion pa hways and changes o he pa hways ha ha e been eco ded du ing 2020–2022.
#: numbe o axa in oduced; # since Dec 2019: change o he numbe o axa in oduced since Decembe 2019 (↗ inc ease; →
no change); IPP: in oduc ion pa hway p ominence (Min: mino ; Mod: mode a e; Maj: majo ; PNP: pa hway no p esen ; ? no
known); IPP since Dec 2019: change o in oduc ion pa hway p ominence since Decembe 2019 [↗ inc ease; ↘ dec ease; → no
change; ? no known; – no applicable ( i s es ima e o new pa hway)].
Co ido
18
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
some o hese plan s a e ha es ed in Sou h A ica (see Sec ion 1.3), plan s a e also impo ed in o he coun y (Williams
e al. 2021b, 2022). These impo ed plan s en e Sou h A ica h ough ai , sea and oad anspo , and o en a i e
h ough he land bo de pos s sha ed wi h Zimbabwe and Mozambique (Williams e al. 2022).
New esea ch on wildli e anches has highligh ed he oppo uni ies o in oduc ion ha hese anches c ea e. The e
a e be ween 4.66 and 7.25 million he bi o ous game animals li ing on wildli e anches ac oss Sou h A ica (Taylo e al.
2021). These anches include eco ou ism and ophy hun ing p ope ies, and so in oduc ion pa hway p ominence
o he ela ed pa hways, hun ing and conse a ion, is ‘Majo ’. Al hough hese anches c ea e many oppo uni ies o
in oduc ions, Sou h A ica has many na i e ungula e species, and so he h ea his pa hway poses in e ms o he
a e o in oduc ion is likely o be low – only wo alien axa [Kobus leche (lechwe), including a ious subspecies, and
Dama dama (common allow dee )] we e eco ded on su eyed p ope ies (Taylo e al. 2021). Such in oduc ions (and
wi hin-coun y mo emen s) ha e he po en ial o sp ead pes s and diseases and impac na i e gene ic di e si y (see
Sec ions 1.3 and 1.4).
1.2 In oduc ion a es
In oduc ion a es conside s he numbe o new alien axa ha ha e been in oduced o e all ime o Sou h A ica
om o he coun ies h ough each o he in oduc ion pa hways, while he high-le el indica o a e o un egula ed
in oduc ion o new species es ima es he o al numbe o new alien axa in oduced acciden ally o illegally each
yea .
O e he las decade (2013–2022), 32 new alien axa
we e ei he illegally o acciden ally in oduced (i.e., un-
egula ed in oduc ions), a a e o app oxima ely h ee
in oduc ions pe yea (Figu e 1.2). This is sligh ly lowe
han he numbe s seen o 2010–2019 (an a e age o
abou ou new axa in oduced pe yea ). This decline is
likely due in pa o delays in he eco ding and epo -
ing o new in oduc ions (see Box 1.1; Table S1.5).
Fo he alien axa o which in oduc ion pa hways a e
known (~1100 alien axa) he in oduc ion pa hways a e
simila o hose p e iously epo ed (Figu e 1.1). Mos in-
oduc ions a e plan s in oduced ei he o o namen al
pu poses and/o ho icul u e (~28%), o o ag icul u e
(~10%). Many alien o ganisms (e.g., in e eb a e pes s)
ha e been acciden ally in oduced along wi h impo ed
plan s, animals o hei p oduc s (~13%); while shipping
has acili a ed many in oduc ions (~9%), h ough he
elease o ballas wa e , h ough bio ouling (including
on hulls), and when o ganisms hi chhike on he ship i -
sel [e.g., Co us splendens ( he house c ow)].
New in oduc ions ha e been epo ed o 22 o he 44
pa hways. Howe e , lags in epo ing and in how in o -
ma ion eeds h ough o his epo con inue o signi i-
can ly a ec he epo ed alues, and o 17 o hese
pa hways hese new in oduc ions we e all eco ded be-
o e 2020 (see Sec ion S1.6). Fo example, he polychae e
Dipolydo a socialis, was i s collec ed in he Knysna Es u-
a y in 2015 bu was only epo ed in 2021, ollowing ge-
ne ic analysis ha con i med i s iden i ica ion (Da id e
al. 2021). This polychae e was likely in oduced o Sou h
Time pe iod
0
20
40
60
80
100
120
Numbe o new alien axa
All in oduc ions Un egula ed in oduc ions
1950−
1959
1960−
1969
1970−
1979
1980−
1989
1990−
1999
2000−
2009
2010−
2019
2020−
2029
Yea
0
5
10
15
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022
Numbe o new alien axa
Figu e 1 .2 . Numbe o new alien axa eco ded in Sou h A ica
o e ime: A, o e he las eigh decades; B, du ing he las
decade. These a e alien axa no p e iously ound o known
o be p esen . The low numbe o ecen un egula ed in o-
duc ions (shaded in g ey) likely e lec s delays in de ec ing
and epo ing alien axa (see Box 1.1). Based on expe iences
om he pas wo epo ing cycles, he numbe o ecen
un egula ed in oduc ions a e likely se e ely unde - epo -
ed, and he numbe epo ed will inc ease as new da a be-
come a ailable (c . Table S1.5).
A
B
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A ica p io o 2015 h ough ballas wa e , hull ouling o wi h o ganisms impo ed o ma icul u e (Da id e al. 2021). In
2020, wo new alien g ass axa we e eco ded in he coun y, Poa humilis and Poa p a ensis subsp. p a ensis (So eng e al.
2020). These axa a e o en seeded o lawns, pas u e and soil s abilisa ion (So eng e al. 2020), and, he e o e, he e has
been an inc ease in he numbe o in oduc ions o e all ime h ough he o namen al, ag icul u e, and s abilisa ion
and ba ie s pa hways (Figu e 1.1). Impo an ly, while he subspeci ic en i y Poa p a ensis subsp. p a ensis may be new
o he coun y, Poa p a ensis (Ken ucky blueg ass) has long been in he coun y and was impo ed and cul i a ed a
pas u e esea ch s a ions om 1934 (Visse e al. 2017). A pa icula ly conce ning new in oduc ion, due o i s po en ial
o ha e nega i e impac s on na i e species, is he ungus Sei idium neocup essi (Wing ield e al. 2022). S. neocup essi,
which causes he disease Cyp ess canke , was i s eco ded in 2021 on he na i e species, Widd ing onia nodi lo a
(moun ain cyp ess) (Wing ield e al. 2022). The exac in oduc ion pa hway o his ungus is no known, bu i was mos
likely in oduced as a con aminan o nu se y ma e ial (Wing ield e al. 2022), and hus he e has been an inc ease in
he numbe o alien axa in oduced h ough his pa hway (Figu e 1.1).
In e ms o egula ed legal in oduc ions, six new biological con ol agen s ha e been eleased agains in asi e plan s
in 2021/2022 (see Sec ion 4.5). While he numbe o in oduc ions o biological con ol has, he e o e, inc eased (Fig-
u e 1.1), his is a well- egula ed pa hway and o minimal conce n in e ms o causing damaging in asions. O e he
pe iod 2020–2022 he e was also one pe mi issued o he impo o an alien axon ha was no al eady eco ded as
legally p esen in he coun y (see Appendix 6). The pe mi was issued o impo Me iones unguicula us, a ype o ge bil,
o be b ed in qua an ine acili ies and used in medical esea ch. Howe e , i appea s ha his axon is al eady p esen
in he pe ade (Shi ambu e al. 2021), hough he legali y o he ini ial impo (s) is no known. I is no known i he
pe mi has been exe cised.
Ac ido he es is is (© Shino Jacob Koo anad).
19
20
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
1.3 Wi hin-coun y pa hway p ominence
Wi hin-coun y pa hway p ominence conside s he oppo uni ies a ailable o he mo emen o o ganisms wi hin
he coun y, and does no ake in o accoun how many dispe sal e en s hese oppo uni ies esul in.
As in p e ious epo s, da a o wi hin-coun y pa hway p ominence we e no a ailable o mos pa hways, and so
he indica o could no be popula ed. Howe e , some gene al ends we e appa en , and ecen esea ch has p o ided
in o ma ion on he in oduc ion oppo uni ies p o ided by some dispe sal pa hways. As discussed abo e, oppo u-
ni ies o in oduc ions o he coun y we e impac ed by he con ols pu in place o educe he sp ead o COVID-19.
These con ols also impac ed he oppo uni ies a ailable, h ough some pa hways, o dispe sal wi hin he coun y.
Fo example, he decline o ~67% in he numbe o domes ic ai c a a i als in he 2020/2021 inancial yea (Figu e
S1.19) was simila o ha o in e na ional and egional ai c a a i als (a decline o 74%). Howe e , he e a e a wide
ange o pa hways ha c ea e dispe sal oppo uni ies wi hin he coun y, and i is likely ha no all we e impac ed o
his ex en . Fu he mo e, hese oppo uni ies a e e u ning o p e-pandemic le els ( o an example see Figu e S1.19).
Recen esea ch has highligh ed he la ge ole ha wildli e anching (Taylo e al. 2021), medicinal plan ade and he
pe ade (Shi ambu e al. 2022a) a e playing in mo ing o ganisms a ound he coun y. A su ey o pe shops indica ed
ha he sou ces o pe s in he ade a e o en local, wi h a leas 40% o he esponden s ob aining hei animals om
local sou ces such as animal escues and o he pe shops o b eeding hem hemsel es (Shi ambu e al. 2022a). Many
o he alien plan s in he medicinal plan ade a e also sou ced locally and mo ed a ound he coun y o his pu pose.
A su ey o he ade in Gau eng and KwaZulu-Na al showed ha 41% o he plan s o sale we e ha es ed in sou h-
e n A ica, wi h mos o hese plan s being sou ced in KwaZulu-Na al (Williams e al. 2021b). Alien plan s ha e been
inco po a ed in o local adi ional medicine no because hey a e used o ea di e en ailmen s han na i e axa, bu
because hey a e e sa ile in e ms o hei uses – hey can be used o many pu poses besides medicine – and many
ha e been in he coun y o a long ime (Yessou ou e al. 2021, 2022).
1.4 Wi hin-coun y dispe sal a es
Wi hin-coun y dispe sal a es conside s he numbe o alien axa ha ha e dispe sed wi hin he coun y h ough
he pa hways o dispe sal, including bo h axa alien o he coun y, and hose ha a e na i e o he coun y bu which
ha e been in oduced o pa s o he coun y whe e hey a e no na i e [so-called na i e-alien popula ions (Nelu ule
e al. 2022); see Box 2.1 o al e na i e e ms ha ha e been used (e.g., ex alimi al species) and easoning o he use
o his e m]. Da a o wi hin-coun y dispe sal ha e no been colla ed o axa ha a e alien o he coun y, and so
he indica o could no be popula ed. Howe e , based on he e iewed li e a u e, alien and na i e axa a e dispe sing
wi hin he coun y h ough a leas 30 o he 44 pa hways (68%) (see Appendix 5 o he da a and sou ces used in his
assessmen ).
O 132 na i e-alien popula ions ha could be ca ego ised wi h con idence, mos we e in en ionally anspo ed o
hei new anges (Nelu ule e al. 2023a) (Table S1.4) and we e ei he in en ionally eleased (44 popula ions o 25 axa) o
escaped om cap i i y and cul i a ion (34 popula ions o 24 axa). These in en ionally in oduced na i e-alien popula-
ions ended o be plan s used o o namen al pu poses (21 popula ions o 16 axa) and mammals in oduced o game
a ms (20 popula ions o 11 axa). The e ha e also been acciden al in oduc ions o na i e axa, including: insec s, gas-
opods, amphibians and ep iles acciden ally anspo ed wi h p oduc s (29 popula ions o 17 axa), especially, plan
p oduc s such as nu se y ma e ials; ep iles and ma ine c us acea anspo ed as s owaways on land ehicles and boa s
(7 popula ions o 3 axa); and ish ha ha e sp ead h ough in e -basin wa e ans e schemes (8 popula ions o 4
axa). No ably, as i is o en di icul o con iden ly asc ibe an in oduc ion pa hway, and as he na i e anges o species
being mo ed a ound a e o en no well delinea ed, i is expec ed ha he numbe o na i e-alien popula ions asc ibed
o he in oduc ion pa hways is likely o be signi ican ly unde es ima ed. This, as well as hei po en ial impac s [see
below example o Phacochoe us a icanus (wa hog) ansloca ions and Box 2.1], means ha he bene i s o managing
wi hin-coun y dispe sal a e likely o be much g ea e han sugges ed by cu en obse ed a es o wi hin-coun y
dispe sal.
21
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
In addi ion o he c ea ion o po en ially in asi e na i e-alien popula ions, he wi hin-coun y mo emen o na i e
axa could ha e a ious nega i e impac s, including ha m ul co-in oduc ions and he loss o na i e gene ic di e si y.
As discussed in Sec ion 1.3, wildli e anches a e acili a ing he mo emen o mammals a ound he coun y and, as a
consequence, mos o hese anches ha e a leas one na i e-alien popula ion, bu some ha e as many as 14 (Taylo
e al. 2021). The mos equen ly ound axa wi h na i e-alien popula ions on hese anches we e Aepyce os melampus
(impala) and T agelaphus angasii (nyala) (Taylo e al. 2021). A ecen gene ic analysis ound ha A ican Swine Fe e
Vi us, a con agious and le hal disease o domes ic pigs, is now ound in he sou h o he coun y, beyond he con olled
a ea decla ed in 1935 (C aig e al. 2022). The ansloca ion o li e Phacochoe us a icanus (wa hog) o game a ms and
na u e ese es ou side o hei his o ical ange has likely played a ole in he dispe sal o he i us (C aig e al. 2022).
Simila ly, a phylogeog aphic analysis o Xenopus lae is (A ican clawed og) and i s monogenean pa asi e P o opoly-
s oma xenopodis indica ed ha human-media ed ansloca ions o X. lae is had led o di e en lineages o he species
coming in o con ac (Schoeman e al. 2022). Bulk expo s o X. lae is om he sou hwes e n pa o he coun y o
u ban cen es in he no h o esea ch and eaching, wi h subsequen escapes, ha e likely played a ole (Schoeman e
al. 2022). Bu X. lae is is also used as bai by ec ea ional angle s, and while some o hese indi iduals escape, angle s
ha e appa en ly also eleased su plus bai and in en ionally s ock wa e bodies o u u e use. The e o e, i is likely ha
h ough ec ea ional ishing indi iduals o di e en lineages a e being mo ed o emo e a eas (Schoeman e al. 2022).
In e ms o he wi hin-coun y dispe sal o axa ha a e alien o he coun y, new esea ch has shown ha people and
ehicles a e acciden ally dispe sing hese o ganisms o he coun y’s p o ec ed a eas, and ha while he in en ional
mo emen o axa a ound by coun y is impo an , na u al dispe sal mechanisms a e also playing a ole a he na ional
le el. Samples aken om he shoes o ail unne s aking pa in aces in he Ga den Rou e Na ional Pa k we e ound o
con ain he seeds o 33 plan species, o which 18 (55%) we e alien o he coun y, and wo we e na i e o he coun y
bu alien o he Ga den Rou e Na ional Pa k (Smi h & K aaij 2020). Along Sani Pass in he Malo i–D akensbe g Pa k, alien
plan axa ha e expanded hei dis ibu ions om lowe o uppe ele a ions, wi h he pa e n o expansion indica ing
ha human-aided long-dis ance dispe sal is playing a ole, likely h ough he adhesion o plan p opagules o ehicles
and he shoes o hike s mo ing up he pass (Tu ne e al. 2021).
Humans also con inue o in en ionally mo e alien axa a ound he coun y o a ious pu poses, and he wi hin-coun-
y dispe sal o some axa is being d i en almos en i ely by hese p ocesses. In Sou h A ica asexual ep oduc ion is
solely esponsible o he na u al dispe sal o he aqua ic mac ophy e Pon ede ia co da a (picke el weed), which is
sp ead ia hizomes, and hus mos o i s wi hin-coun y dispe sal is likely pe pe ua ed by ga dene s and ho icul u is s
ha ade in he axon, and dump plan s and p opagules; and ish a me s and gol cou se owne s ha may be using
he axon o s abilise wa e bodies and banks (Wansell e al. 2022). A Bayesian dynamic species dis ibu ion model ha
was used o model he in asion o he plan Plec an hus ba ba us a . g andis (also known as Plec an hus ba ba us, Ab-
yssinian coleus) in he sou he n Cape, showed he in asion o his species was also la gely d i en by human-media ed
long-dis ance dispe sal ha o igina ed om he ci ies o i s in oduc ion (Bo ella e al. 2022). Wi hou human-medi-
a ed long-dis ance dispe sal, he maximum popula ion size o P. ba ba us a . g andis would ha e been only 30% o
he cu en popula ion size (Bo ella e al. 2022). Na u al p ocesses a e also playing an impo an ole in he dispe sal o
some alien axa. Compa isons be ween alien plan ichness a dump si es and in he p o inces in which he dump si es
a e ound, ha e indica ed ha alien plan p opagules a e being dispe sed be ween locali ies in Sou h A ica, wi h he
dispe sal o some o hese axa likely being acili a ed by omni o ous bi ds ha ly long dis ances (Moko jomela e al.
2022).
22
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Box 1.1. Wo k o imp o e he pa hway indica o s
The implemen a ion, o e h ee epo s, o he indica o s used he e o epo on he s a us o pa hways has high-
ligh ed se e al issues.
Pa hway amewo ks a e used o classi y simila pa hways in o disc e e ca ego ies. A pa hway amewo k p o-
posed by he CBD as a global s anda d (CBD 2014; Essl e al. 2015; Scale a e al. 2016) has been se as a global
biodi e si y s anda d by he Da win Co e (dwc:pa hway) (G oom e al. 2019). Because o his, he amewo k (see
Figu e 1.1) was inco po a ed in o he pa hway indica o s used in his epo (Wilson e al. 2018). Howe e , imple-
men ing he amewo k in he Sou h A ican con ex has been a challenge (Van Wilgen & Wilson 2018; Zengeya &
Wilson 2020), and a numbe o issues ha e been iden i ied (see Faulkne e al. 2020a). Wo k is cu en ly unde way
o de elop and es a amewo k ha will mee Sou h A ica’s needs, by acili a ing epo ing a bo h in e na ional
and na ional le els, and in o ming managemen ; his will be a ea u e o he nex epo .
The high-le el indica o a e o un egula ed in oduc ion o new species is based on he obse ed a e o
in oduc ions (Wilson e al. 2018). Howe e , his is well known o be a biased me ic ha can lead o misleading
pa e ns. A axon ecen ly eco ded o he i s ime in he coun y, could ha e been in he coun y o many
decades (Box Figu e 1.1), and his eco ding delay will impac he a e o in oduc ion i es ima ed based on aw
in oduc ion eco ds (Solow & Cos ello 2004; Belmake e al. 2009). The e o e, es ima es o in oduc ion a es mus
conside he a e o disco e y, which is o en unknown. To add ess his, an indica o a e o in asi e alien species
sp ead has been de eloped h ough he sTWIST p ojec [c . Box 0.2; and he p ep in by McGeoch e al. (2021)].
Mo eo e , Ta ge 6 o he Kunming Mon eal Global Biodi e si y F amewo k (Box 0.2) has a p oposed headline
indica o Numbe o in asi e alien species in oduc ion e en s. The nex epo will pilo hese app oaches o
ob ain unbiased es ima es o in oduc ion a es in line wi h he CBD’s Global Biodi e si y F amewo k.
Box Figu e 1 .1 . Examples o alien axa in Sou h A ica ha we e i s eco ded many yea s a e hey a e belie ed o ha e been
in oduced: A, Anisolabis ma i ima ( he ma i ime ea wig) (G i i hs 2018); B, Ra us anezumi ( he Asian house a ) (Bas os
e al. 2005, 2011); C, Euwallacea o nica us ( he polyphagous sho -hole bo e ) (S ou hame e al. 2017). Pho og aphs: A,© J.
Gallaghe ; B, © Nasse Halaweh; C, © Ga yn Townsend.
A B
C
23
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
1.5 T ends in pa hway indica o s
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
1. Ra e o
un egula ed
in oduc ion
o new
species
→low ↘O e he las decade (2013–2022)
app oxima ely h ee new axa we e
in oduced pe yea ei he acciden ally
o in en ionally bu illegally. This is
simila o p e ious es ima es.
Es ima ed a es o in oduc ion a e sensi i e o sea ch
e o and he e is o en a delay o se e al yea s be ween
in oduc ions happening and hem being o mally eco ded
(Box 1.1). New me hods and app oaches a e needed o
ensu e ha es ima es o a es o un egula ed in oduc ion
a e esponsi e and can be used o e alua e he e ec i eness
o in e en ions.
The a e o in oduc ion o un egula ed axa is expec ed o
be a unc ion o he olume o ade and a el. Howe e ,
his will depend on he deg ee o which key pa hways a e
iden i ied, p io i ised and managed. See Chap e 4 o de ails
on some posi i e de elopmen s ha could s eng hen
Sou h A ica’s biosecu i y.
1.1 In oduc ion
pa hway
p ominence
→medium no
applicable
13 in oduc ion pa hways play a majo
socio-economic ole.
The e ha e been ew quali a i e
changes o his du ing he pe iod
2020–2022 despi e empo a y
quan i a i e educ ions due o
COVID-19 esponse measu es. Fo
wo pa hways in oduc ion pa hway
p ominence was es ima ed o he i s
ime.
The ade and a el con ols pu in place o p e en
he sp ead o COVID-19 caused a empo a y decline in
some in oduc ion oppo uni ies, bu hese in oduc ion
oppo uni ies a e e u ning o p e-pandemic le els and
ends. Unless ends in a el and ade a e acked and
in e en ions espond o such changes, new ha m ul alien
species will con inue o be in oduced. I , howe e , e ec i e
biosecu i y measu es a e in place, he new biological
in asions caused by inc eases in a el and ade will be
educed.
→ no change; ↗ an inc ease; ↘ a dec ease.
24
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
1.2 In oduc ion
a es
→Low no
applicable
( o
egula ed
axa)
↘
( o
un egula ed
axa)
Fo egula ed axa: du ing 2020–2022,
six new axa we e legally in oduced o
biological con ol and one axon ha
was al eady in he coun y was legally
in oduced o o he pu poses.
Fo un egula ed axa: du ing 2020–
2022, one new axon was acciden ally
in oduced p obably as a con aminan
o nu se y ma e ials, and wo new axa
we e in oduced o o namen al o
ag icul u al pu poses, o o s abilise
soil. Howe e , se e al axa in oduced
and eco ded p io o 2020 we e
epo ed o he i s ime du ing 2020–
2022. These axa we e likely in oduced
h ough 17 di e en in oduc ion
pa hways. The e is no s ong e idence
ha he numbe o axa in oduced
h ough he di e en pa hways has
changed g ea ly.
In many cases egula ed axa ( o which he isks ha e been
analysed and ound o be accep able) a e expec ed o be
a ne bene i o he coun y, and in he case o biological
con ol, assis wi h he con ol o biological in asions.
S ingen p ocesses a e in place o minimise he isk ha
such in oduc ions esul in ha m ul in asions (Sec ion 4.1. in
Chap e 4).
Unless pa hways a e iden i ied, p io i ised and managed,
po en ially ha m ul alien axa will con inue o be
acciden ally and illegally in oduced.
1.3 Wi hin-
coun y
pa hway
p ominence
no assessed no
applicable
In o ma ion was only ob ained o
a ew pa hways. Many pa hways a e
likely playing an impo an socio-
economical ole, bu he ex en o his
ole and how i has changed ecen ly
is no known. Res ic ions on wi hin-
coun y ade and a el o p e en he
sp ead o COVID-19 had a sho - e m
impac on he wi hin-coun y dispe sal
oppo uni ies p o ided by some
pa hways.
In e nal ade and anspo a e expec ed o inc ease o e
ime. T ends in hese pa hways need o be acked o ensu e
in e en ions a e in place whe e hey a e needed. I his is
no done, ha m ul axa will con inue o sp ead, na i e axa
will be in oduced and possibly cause impac s in pa s o he
coun y whe e hey a e no na i e, and aluable asse s will
be pu a isk.
→ no change; ↗ an inc ease; ↘ a dec ease.
25
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
1.4 Wi hin-
coun y
dispe sal
a es
no assessed no
applicable
( o
egula ed
axa)
↘
( o
un egula ed
axa)
Alien and na i e axa a e dispe sing
wi hin he coun y h ough a leas 30
di e en pa hways. Na ional-scale da a
ha e ye o be colla ed o alien axa,
bu in o ma ion has become a ailable
o na i e-alien popula ions. Mos
eco ded na i e-alien popula ions a e
plan s in oduced o ho icul u e, o
mammals o aes he ics. Bu na i e-
alien popula ions a e also he esul o
acciden al in oduc ions, o example,
o ganisms mo ed wi h anspo ed
plan s o plan p oduc s, o ha
dispe se h ough in e -basin wa e
ans e schemes. Alien o ganisms a e
being in oduced, o en acciden ally,
o p o ec ed a eas, and while human-
aided dispe sal is d i ing he dispe sal
o some axa, na u al p ocesses a e also
playing an impo an ole a a na ional
scale.
Unless pa hways ha acili a e he wi hin-coun y dispe sal
o axa a e iden i ied, p io i ised and managed, he sp ead
o hese axa will inc ease, and so he e will be inc eases in
bo h he a e o expansion o cu en ly in asi e axa, and in
he likelihood ha alien axa will ind a sui able pa o he
coun y in which o become in asi e.
Na i e-alien popula ions likely di e in hei impac s o o he
alien popula ions, and o in o m pa hway managemen ,
he e is a need o imp o e ou unde s anding o he ex en
o his p oblem, and how hese popula ions a e being
in oduced.
→ no change; ↗ an inc ease; ↘ a dec ease.
32
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
2.4 Impac o alien species
A ecen e iew o he ecological and social impac s o biological in asions in Sou h A ica con i med p e ious indings.
Expe s belie e many in asi e species cause ‘Majo ’ nega i e impac s on biodi e si y. Howe e , he e a e ew s udies
ha o mally documen impac s (see Supplemen a y Ma e ial S2.5; Zengeya & Wilson 2020; Van Wilgen e al. 2022b).
An e alua ion o he mone a y cos s o in asions o Sou h A ica has ecen ly been comple ed using he In aCos me h-
odology (see Box 3.1), hough e en ewe s udies con ained ele an in o ma ion han hose analysed by Van Wilgen
e al. (2022b).
Na ional-le el EICAT assessmen s ha e been comple ed o 36 species (Table 2.2), wi h h ee o hese axa es ima ed
o ha e ‘Mode a e’ impac s, 18 ‘Majo ’ impac s and one a ‘Massi e’ impac . The seemingly high p opo ion o axa wi h
ha m ul impac s is, howe e , an a e ac as axa known o cause impac we e p io i ised o assessmen . As e o s o
colla e in o ma ion on he impac s o alien species using s anda dised p o ocols inc ease, a mo e comple e pic u e will
eme ge. Examples o plan axa assessed o da e include: Eucalyp us camaldulensis ( ed gum) ha o ms dense hicke s
along wa e ways and domina es o excludes na i e ege a ion (Te e ai e al. 2013; Hi sch e al. 2020); wo Nel uma
species (p e iously P osopis; mesqui e) ha compe i i ely displace na i e ege a ion, bi ds and in e eb a e commu-
ni ies (S eenkamp & Chown 1996; Dean e al. 2002; Schach schneide & Feb ua y 2013); i e Aus alian Acacia species
(wa les) ha cause ‘Majo ’ impac s on na i e species h ough compe i ion and changes o ecosys em unc ioning
(Jansen & Kumschick 2022); and Lan ana cama a (lan ana) and Ch omolaena odo a a ( i id weed) ha cause physical
changes o ecosys em s uc u e, leading o a change in in e eb a e species communi y composi ion wi h a decline in
some axa and a loss o o he s (Samways e al. 1996; Mgobozi e al. 2008). In e ms o animals, Linepi hema humile ( he
A gen ine an ) compe i i ely displaces and educes he abundance o na i e an s (Schoeman & Samways 2011). Few
na ional-le el Socio-Economic Classi ica ion o Alien Taxa (SEICAT) assessmen s ha e been done in Sou h A ica (see
Supplemen a y Ma e ial S2.5).
Alien species can cause bo h posi i e and nega i e en i onmen al impac s (Vime ca i e al. 2020). A majo ad ance
since 2019 in moni o ing he impac o alien species has been he de elopmen o he EICAT+ amewo k (Vime ca i
e al. 2022) ha enables he classi ica ion o posi i e impac s o alien axa on na i e biodi e si y. The amewo k can be
applied o all alien axa and a di e en spa ial and o ganisa ional scales. I EICAT+ is used in combina ion wi h EICAT, i
can help o o ecas unwan ed consequences o alien axa con ol. EICAT+ can also help quan i y he deg ee o which
es o a ion and biocon ol p og ammes based on alien species o e posi i e ou comes o na i e biodi e si y conse a-
ion (e.g., iden i y biological con ol agen s ha o e he highes posi i e impac s on na i e biodi e si y).
Table 2 .2 . The numbe o axa ha ha e impac assessmen s o Sou h A ica in e ms o he En i onmen al Impac Classi ica ion
o Alien Taxa (EICAT) as o Decembe 2022 (see Table S2.4 o mo e de ails). Only ou axa (all ees and sh ubs), ha e impac
assessmen s o Sou h A ica in e ms o he Socio-Economic Classi ica ion o Alien Taxa (SEICAT).
G oup Da a
De icien
Minimal
Conce n
Mino Mode a e Majo Massi e To al
G asses, annuals and ines 7 0 2 2 2 0 13
T ees and sh ubs 0 1 0 1 11 0 13
F eshwa e ishes 0 0 0 0 4 1 5
F eshwa e in e eb a es 4 0 0 0 0 0 4
Te es ial in e eb a es 0 0 0 0 1 0 1
To al 11 1 2 3 18 1 36
33
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Box 2.1. Na i e-alien popula ions
Species ha a e na i e o Sou h A ica ha e been in en ionally and acciden ally mo ed a ound he coun y by
humans and in oduced o pa s o he coun y whe e hey a e no na i e (see Sec ion 1.4 and Table S1.4. o de-
ails on pa hways o dispe sal). In a ecen pape , Nelu ule e al. (2022), sys ema ically e iewed he phenomenon
and de ined i as a ‘popula ion ha is: 1) wi hin a coun y o which he species is na i e, 2) ounded by indi iduals
mo ed by di ec human agency [o subs an ial indi ec human agency, see (Essl e al. 2018)], 3) o e a biogeo-
g aphical ba ie , and 4) o an a ea beyond he species’ na i e ange’. A a ie y o e ms ha e been used o his
phenomenon in Sou h A ica, including ‘ex alimi al in oduc ions’ (Ellende & Weyl 2014) and ‘domes ic exo ics’
(Measey e al. 2017); howe e , building on he e m used in he Global Regis e o In oduced and In asi e Spe-
cies (Pagad e al. 2018), and o mo e closely e lec exis ing e minology, he e m ‘na i e-alien popula ions’ was
adop ed (Nelu ule e al. 2022).
To acili a e up ake in o policy, managemen , and epo ing, Nelu ule e al. (2023b) de eloped a p o ocol o clas-
si y na i e-alien popula ions, and, using his p o ocol, colla ed an in en o y o na i e-alien popula ions in Sou h
A ica (Nelu ule e al. 2023a). The in en o y con ains in o ma ion on 77 na i e axa om nine classes ha ha e
o med 132 na i e-alien popula ions ac oss he e es ial (101 popula ions), eshwa e (26 popula ions), and
ma ine en i onmen s (5 popula ions). Mos o hese popula ions a e es ablished (59%), bu a ew a e in asi e
(18%). Some o hese na i e-alien popula ions ha e had signi ican nega i e impac s (Box Figu e 2.1). Al hough
he phenomenon appea s o be a e in compa ison o he numbe o alien species in oduced om o he coun-
ies (Sec ion 2.1), na i e-alien popula ions a e unde - epo ed.
Na i e-alien popula ions a e unde s udied globally and hey dese e mo e a en ion (Vi ule e al. 2019). This is
because al hough hese popula ions a e a subse o alien popula ions, hey end o di e om o he alien popula-
ions in e ms o hei in asion po en ial and he ype o impac s hey ha e. They also pose a speci ic managemen
and egula o y challenge, and as hei p e alence will likely inc ease wi h global change (Nelu ule e al. 2022). The
de ini ion, p o ocol, and da abase ha a e now a ailable will make i possible o moni o and epo on he s a us
o hese na i e-alien popula ions.
Box Figu e 2 .1 . Taxa wi h na i e-alien popula ions in Sou h A ica ha ha e h ea ened na i e biodi e si y h ough hyb idisa-
ion. A, popula ions o Labeo capensis (O ange Ri e mud ish) ansloca ed o he Eas e n Cape ha e hyb idised wi h L. um-
b a us (moggel), leading o in og ession and h ea ening moggel’s gene ic in eg i y (Ramoejane e al. 2020); B, Damaliscus
pyga gus subsp. phillipsi (blesbok) na i e-alien popula ions in he Wes e n Cape hyb idised wi h he endemic D. p. subsp.
pyga gus (bon ebok), and only h ough conce ed and in ensi e in e en ions was he ex inc ion o bon ebok p e en ed
(Van Wyk e al. 2017). Pho og aphs: A, © M. Desai; B, © B. Dupon .
A B
34
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
2.5 T ends in species indica o s
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
2. Numbe
o in asi e
species ha
ha e ‘Majo ’
impac s
↗low
(many
axa s ill
need o be
assessed)
↘The impac o 36 in asi e species has
been assessed using he me hodology
o he IUCN’s En i onmen al Impac
Classi ica ion o Alien Taxa (EICAT)
scheme. O hese, 19 a e epo ed o
cause ‘Majo ’ o ‘Massi e’ impac s in
mainland Sou h A ica.
The numbe o in asi es ha ha e ‘Majo ’ impac s will
inc ease as mo e impac assessmen s a e conduc ed. The
o mal assessmen o he impac o alien species p o ides
he a ionale o egula ion and managemen , can imp o e
compliance and implemen a ion o in e en ion measu es,
and assis o esol e con lic s. Howe e , impac assessmen s
a e hampe ed by a lack o eliable da a o mos species. I his
si ua ion pe sis s, egula ions will con inue o be ulne able o
legal challenges. I is e y di icul o con ol in asi e species
wi h ‘Majo ’ impac s in a way ha will educe such impac s
o ‘Mode a e’ o ‘Mino ’, bu his has a guably been achie ed
by biological con ol o o e 30 in asi e axa. Ongoing
in es men in biological con ol will likely esul in mo e such
successes. I alien species ha cu en ly ha e ‘Mode a e’ o
‘Mino ’ impac s a e p e en ed om inc easing in abundance
and ex en o he poin whe e hey ha e ‘Majo ’ impac s o ,
whe e easible, such species a e e adica ed om Sou h A ica,
hen signi ican e u ns on in es men migh also be made.
2.1 Numbe and
s a us o
alien species
↗high ↘
( o in asi e
species)
O 3511 alien axa sys ema ically
eco ded as p esen in Sou h A ica,
o e a hi d a e in asi e.
The p ocess o documen ing and
acking changes in he s a us o
alien species has been subs an ially
imp o ed h ough he de elopmen
o wo k lows o ensu e ha wo k is
p ope ly documen ed and epea able.
Sou h A ica aces a subs an ial in asion deb because mos
alien species a e no ye in asi e and new alien species
con inue o a i e. The numbe o alien species eco ded in
he coun y will inc ease i mo e e o is spen on de ec ion,
e en o well-s udied g oups like plan s. The upda ed alien
species lis con ained in his epo ep esen s a s ep owa ds
a na ional egis y o alien species in he coun y. I cap u es
he cu en s a e o knowledge o he s a us o each alien
species in a manne ha allows o he in o ma ion o be
easily e iewed and upda ed. This p omises o p o ide he
ounda ional biodi e si y in o ma ion ha is essen ial o
manage s and policymake s.
→ no change; ↗ an inc ease; ↘ a dec ease.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
2.2 Ex en o
alien species
→medium ↘The majo i y o alien species ha e
limi ed dis ibu ion bu many o hese
a e inc easing in ex en .
The majo i y o alien species a e localised and only a ew
a e widesp ead. Howe e , he po en ial o hem o inc ease
hei dis ibu ion is la ge and he ex en o mos species will
con inue o inc ease unless e ec i e con ol is pu in place.
2.3 Abundance
o alien
species
no assessed ↘No new da a we e a ailable on he
abundance o alien species.
Unde s anding ends in abundance is impo an i he
e ec i eness o managemen in e en ions is o be
moni o ed, and he magni ude o u u e impac s p edic ed.
2.4 Impac o
alien species
↗medium ↘19 species ha e been epo ed o cause
‘Majo ’ o ‘Massi e’ impac s using he
IUCN’s EICAT scheme. Howe e , as mos
in asi e axa ha e no been assessed,
his numbe is expec ed o inc ease
wi h ime.
This emains a majo gap whe e de ailed esea ch is needed.
Unless he impac s o in asi e species can be quan i ied,
a emp s o egula e hem will emain con en ious in many
cases.
→ no change; ↗ an inc ease; ↘ a dec ease.
A aujia se ici e a (© SAPlan s).
35
36
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Sphagne icola iloba a (© SAPlan s).
36
37
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
CHAPTER
3
SITES
Lead au ho s: Tsungai Zengeya,
Emily J. McCulloch-Jones & B ian
W. an Wilgen
Con ibu ing au ho s: Nicholas Cole &
And ew A. Tu ne
Findings o si es
• Alien species a e dis ibu ed ac oss he coun y, wi h mos
b oad-scale adminis a i e uni s and biogeog aphical egions
being in aded by a a ie y o axa. Mos alien species a e
ound in he Wes e n Cape, Eas e n Cape and KwaZulu-Na al.
Reco ded alien species ichness is also highes a ound ma-
jo u ban cen es. A ecen inc ease in eco ded alien species
ichness a ound u ban a eas is due o an inc ease in eco ds
om ci izen science pla o ms such as iNa u alis .
• The ela i e abundance o in asi e plan species has been es-
ima ed o p o ec ed a eas managed by SANPa ks and Cape-
Na u e. In asions in hese p o ec ed a eas we e ound o be
mino o ex ensi e and hese es ima es ha e no changed
since 2019.
• Biological in asions con inue o cause majo impac s on biodi-
e si y, ecosys em se ices, and human li elihoods by educ-
ing Sou h A ica’s wa e esou ces, deg ading pas u elands,
and exace ba ing i es. These es ima es need o be egula ly
eassessed. Wo k is ongoing o de elop sys ema ic p ocesses
o e alua e impac s udies, o scale up and link es ima es o
o he biodi e si y assessmen p ocesses, and o inco po a e
p e ious s udies o allow o acking ends o e ime.
Clea ing o alien plan s in he Wes e n Cape (© Wesley Black).
38
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Gaps o species and si es1
• Da a on he dis ibu ion and abundance o alien species need o be collec ed, colla ed and in eg a ed in o na ional
and global da abases o acili a e he planning o in e en ions.
• The sys ema ic quan i ica ion o he impac s o biological in asions would: acili a e he p io i isa ion o in e en-
ions a ge ing pa icula species and pa icula si es; p o ide he jus i ica ion o go e nmen in es men o con ol
biological in asions; and p o ide impo an backg ound o communica e he issue o socie y.
Indica o s co e ed in he si es chap e
1The gaps lis ed a e he same as in he second epo as he si ua ion has no changed.
3.3 Impac o in asions
3.2 Rela i e in asi e abundance
3.1 Alien species ichness
s
e
i
S
3.1 Alien species ichness
Alien species a e dis ibu ed ac oss he coun y, wi h mos b oad-scale adminis a i e uni s and biogeog aphical e-
gions being in aded by a a ie y o axa (Table 3.1 and Table S3.1–S3.3). A a p o incial scale, he e has been subs an ial
changes in alien species ichness (Table 3.1). Mos alien plan species a e ound in he Wes e n Cape, Eas e n Cape
and KwaZulu-Na al (Table 3.1a). The mos p ominen inc ease in he numbe o alien plan axa pe p o ince was in he
Wes e n Cape, Gau eng and Limpopo. The e we e mode a e o low inc eases in alien species ichness in he o he
p o inces (Table 3.1a). Alien plan species ichness was highes in Fynbos, Sa anna and G assland biomes, and lowes
in Dese and Fo es biomes (Table 3.1b). Alien species ichness doubled o mo e in mos biomes (Abany Thicke ,
Dese , Fynbos, Fo es and Succulen Ka oo) and inc eased by a leas a hal in he o he biomes. Twen y- h ee (23) alien
eshwa e ishes ha e been eco ded in Sou h A ica’s Wa e Managemen A eas (WMAs), wi h o e 10 species being
eco ded in he Be g, Koma i, Mkomazi, M olozi and Tugela (Table 3.1c). The e ha e been ew ecen changes o hese
numbe s.
The obse ed inc eases in alien species ichness a e la gely a esul o eco ds on iNa u alis ( o plan s) and digi isa-
ion o his o ical eco ds by he F eshwa e Biodi e si y In o ma ion Sys em ( o ish) eeding h ough o GBIF (Figu e
S2.1). Alien species ichness o ma ine eco egions was no upda ed. Comp ehensi e es ima es o alien species
ichness a e limi ed o small a eas and o pa icula axa [e.g., McLean e al. (2018); Baa d & K aaij (2019); Cheney e
al. (2019)]. B oad-scale alien species ichness es ima es a e usually eliably es ima ed only o in asi e species, no ing
ha he in oduc ion s a us o alien species (i.e., he deg ee o which a species has es ablished and become in asi e)
was also no upda ed in his epo .
39
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table 3 .1 . Alien species ichness in Sou h A ica o di e en b oad-scale adminis a i e uni s and biogeog aphical egions. The es-
ima es o change a e made wi h low con idence because mos epo ed inc eases a ise om he o mal eco ding o species ha
ha e p obably been p esen o some ime. The alues a e based on eco ds a ailable om GBIF (h ps://www.gbi .o g/) and he
Sou he n A ican Plan In ade s A las (SAPIA) o con inen al Sou h A ica; and Robinson e al. (2020) o ma ine eco egions. Fu he
de ails a e p o ided in he Supplemen a y Ma e ial, see Appendix 2 o he ull species lis . In o ma ion on alien species ichness in
he P ince Edwa d Islands is p esen ed in Chap e 5 and he accompanying appendices and Supplemen a y Ma e ial.
a) Alien e es ial and eshwa e plan species ichness pe
p o ince.
P o ince End o
2019
End o
2022
Inc ease
Eas e n Cape 463 615 152
F ee S a e 220 283 63
Gau eng 308 540 232
KwaZulu-Na al 542 708 166
Limpopo 277 467 190
Mpumalanga 344 457 113
No he n Cape 174 221 47
No h Wes 215 289 74
Wes e n Cape 504 841 337
b) Alien plan species ichness pe biome.
Biome End o
2019
End o
2022
Inc ease
Albany Thicke 99 261 162
Dese 5 10 5
Fynbos 300 660 360
Fo es 38 113 75
G assland 293 494 201
Indian Ocean
Coas al Bel
234 393 159
Nama-Ka oo 67 128 61
Sa anna 314 587 273
Succulen Ka oo 55 134 79
c) Alien eshwa e ish species ichness pe Wa e Manage-
men A ea.
Wa e
Managemen
A ea
End o
2019
End o
2022
Inc ease
A–Limpopo 8 9 1
B–Oli an s No h 9 10 1
C–Vaal 8 9 1
D–O ange 7 8 1
E–Oli an s Wes 7 7 0
F–Bu els 0 0 0
G–Be g 13 15 2
H–B eede 8 9 1
J–Gou i z 7 8 1
K–K om 9 10 1
L–Gam oos 6 7 1
M–Swa kops 6 6 0
N–Sundays 4 5 1
P–Bushmans 4 5 1
Q–G ea Fish 6 6 0
R–Keiskamma 6 6 0
S–Kei 10 10 0
T–Mzim ubu 8 9 1
U–Mkomazi 12 13 1
V–Tugela 16 17 1
W–M olozi 11 12 1
X–Koma i 11 12 1
40
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A a qua e -deg ee g id cell (qdgc) scale, only 9% o qdgcs (184 ou o 1966) had 50 o mo e alien axa. The eco ded
alien species ichness o bi ds and plan s appea s o be highes a ound majo u ban cen es (Figu e 3.1a, c). This is
likely because some species a e commensal wi h humans, mos we e i s in oduced o u ban cen es, and because o
g ea e sampling a ound u ban a eas. Inc eases in obse a ions om ci izen scien is pla o ms such as iNa u alis ( o
plan s) and he Sou he n A ican Bi d A las P ojec 2 ( o bi ds) will ha e con ibu ed o he inc eases in alien species
ichness a ound u ban a eas (Figu e 3.1b, d and S3.1).
In o ma ion on alien species ichness was also a ailable o SANPa ks and Cape Na u e p o ec ed a eas (Table 3.1e).
No p o ec ed a ea complex is alien- ee, bu he dis ibu ion o in asi es be ween p o ec ed a eas is highly skewed.
The numbe o in asi e species (excluding biocon ol agen s and ma ine species) ha a e epo ed o occu ac oss he
SANPa ks es a es a e 1014. O hese, he e a e 256 animal species and 758 plan species. O hese axa 333 a e lis ed
unde he A&IS Regula ions, he emaining 681 species a e unlis ed. Th ee p o ec ed a eas (Ga den Rou e Na ional
Pa k, K uge Na ional Pa k and Table Moun ain Na ional Pa k) had mo e han 100 in asi e species. In 2022, Cape Na u e
lis ed 759 in asi e species ac oss hei es a e o 31 p o ec ed a ea clus e s. The numbe o in asi e species included 502
plan s and 257 animals, o which 404 a e lis ed unde he A&IS Regula ions.
3.2 Rela i e in asi e abundance
The e a e no coun y-wide es ima es o he ela i e abundance o in asi e species. Es ima es a e a ailable o in asi e
plan s in p o ec ed a eas managed by he Sou h A ican Na ional Pa ks and Cape Na u e. Es ima es o ela i e in asi e
abundance in hese p o ec ed a eas om 2019 indica e ha in asions we e ‘Mino ’ o ‘Ex ensi e’ (Table 3.2). The e ha e
been no majo changes o hese es ima es.
d) Ma ine in asi e species ichness pe
ma ine eco egion (no upda ed o
2022).
Ma ine eco egion End o
2019
Agulhas 41
Na al 25
Delagoa 8
Sou he n Benguela 39
Sou heas A lan ic
(o sho e)
0
Sou hwes Indian
(o sho e)
0
e) In asi e species in p o ec ed a eas in Sou h A ica.
In asi e
species
ichness
Cape Na u e SANPa ks
End o
2019
Augus
2021
Inc ease End o
2019
End o
2022
Inc ease
0 0 0 0 0 0 0
1–10 3 3 0 0 0 0
10–20 10 10 0 6 6 0
21–30 4 4 0 3 3 0
31–40 10 10 0 4 4 0
41–50 3 3 0 1 1 0
>50 1 1 0 6 6 0
Table 3 .1 . (Con inued) Alien species ichness in Sou h A ica o di e en b oad-scale adminis a i e uni s and biogeog aphical e-
gions. The es ima es o change a e made wi h low con idence because mos epo ed inc eases a ise om he o mal eco ding o
species ha ha e p obably been p esen o some ime. The alues a e based on eco ds a ailable om GBIF (h ps://www.gbi .o g/)
and he Sou he n A ican Plan In ade s A las (SAPIA) o con inen al Sou h A ica; and Robinson e al. (2020) o ma ine eco egions.
Fu he de ails a e p o ided in he Supplemen a y Ma e ial, see Appendix 2 o he ull species lis . In o ma ion on alien species
ichness in he P ince Edwa d Islands is p esen ed in Chap e 5 and he accompanying appendices and Supplemen a y Ma e ial.
41
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table 3 .2 . Es ima es o ela i e in asi e abundance in Sou h A ica’s p o ec ed a eas based on pe cen age plan co e . Alien- ee
means ha no alien species we e eco ded in he p o ec ed a ea.
Rela i e in asi e
abundance
Numbe o Cape Na u e’s p o ec ed a eas Numbe o SANPa ks’ p o ec ed a eas
2018 2021 2019 2022
Alien- ee 0 0 0 0
Mino <2% 12 11 14 14
Mode a e 2–10% 5 7 2 2
Ex ensi e 10–50% 12 11 0 0
Dominan >50% 0 0 0 0
Figu e 3 .1 . Alien species ichness o bi ds and plan s in Sou h A ica pe qua e -deg ee g id cell (qdgc) as o Decembe 2022 and
he change in hese alues since Decembe 2019. A, alien bi d species ichness; B, inc eases in alien bi d species ichness; C, alien
plan species ichness; D, inc eases in alien plan species ichness. Maps a e based on occu ence eco ds om GBIF and SAPIA.
A
C
B
D
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Acacia cyclops (© SAPlan s).
48
• One hi d o he 560 axa lis ed unde he NEM:BA A&IS Regula ions and a u he 136 un egula ed species, ha e
been subjec ed o some o m o con ol o e he pas h ee yea s.
• Mos species subjec ed o con ol we e plan s (236 species) o insec s (76 species).
• The e ec i eness o con ol could only be es ima ed o 30% o he ea ed species. Se en een (17) species we e
assessed as being unde pe manen con ol and a u he 41 as being unde e ec i e con ol (based p edominan ly
on an assessmen o biological con ol).
• The a ea co e ed by cu en si e managemen plans has mo e han doubled ( om 2.4 o 5.3 millionha) since 2016;
and he e has been a subs an ial imp o emen in he adequacy o planning.
• Con ol ope a ions eached 1% o he es ima ed in aded a ea be ween 2020 and 2022. The e is e idence ha con-
ol e o s ha e educed he a ea in aded a some si es, bu mos in asi e species ha e con inued o expand hei
ange when assessed a a na ional scale.
Gaps o in e en ions1
• A comp ehensi e policy, and a s a egy o implemen such a policy, is needed o guide in e en ions on biological
in asions in Sou h A ica.
• A lack o adequa e planning wi h clea goals and he pauci y o moni o ing o he ou comes o in e en ions in
e ms o hei impac s on biological in asions emain cons ain s o e ec i e managemen and a subs an ial imped-
imen o assessing he e ec i eness o con ol measu es.
1These key gaps ha e no changed since he second epo .
49
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o s co e ed in he in e en ions chap e
OUTCOMES
4.7 Effec i eness o
pa hway ea men s
OUTPUTS
4.4 Pa hways ea ed
INPUTS
4.8 Effec i eness o
species ea men s
4.1 Quali y o egula o y
amewo k
4.5 Species ea ed 4.2 Money spen
4.9 Effec i eness o si e
ea men s 4.6 Si es ea ed 4.3 Planning co e age
s
n
o
i
n
e
e
n
I
4.1 Inpu – quali y o he egula o y amewo k
Be ween Janua y 2020 and Decembe 2022, he p ima y legisla ion go e ning biological in asions in Sou h A ica ( he
NEM:BA o 2004) has no changed1. Howe e , e isions o he NEM:BA A&IS Regula ions o 2014 and he Lis s o 2016
we e published in Sep embe 2020 (see Supplemen a y Ma e ial S4.1 o he ull de ails). The e ised egula ions and
lis s came in o o ce on 1 Ma ch 2021, wi h he inclusion o wo in asi e ou species, Onco hynchus mykiss ( ainbow
ou ) and Salmo u a (b own ou ), suspended un il u he no ice.
Se e al key changes a e highligh ed below ( o ull de ails see Supplemen a y Ma e ial S4.1):
• P o ision o ‘Ca ego y 1b Con ol Plans’ (includes axa in o he ca ego ies ha a e beyond pe mi ed o exemp
a eas).
• Po s o en y o impo a e speci ied.
• A gene al obliga ion is speci ied equi ing e o s o p e en sp ead and con ol any escapes o lis ed alien axa.
• The emo al o he p ohibi ed lis .
• Applica ions o pe mi s o lis ed alien axa need o include in o ma ion speci ied in he ‘Risk assessmen amewo k’.
• The issuing au ho i y mus no i y po en ially a ec ed municipali ies (no jus p o inces) o an applica ion o a pe mi .
1The Na ional En i onmen al Managemen Laws Amendmen Ac , 2022 came in o e ec 30 June 2023.
50
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
• Whe e o he egula o y p ocesses also go e n he es ic ed ac i i ies, and he issuing au ho i y is also he deci-
sion-make in e ms o he o he egula o y p ocesses, he applicable decision-making ime ames mus be aligned.
• Pe mi s may be issued o a pe iod no exceeding en yea s (p e iously i e) unde speci ic ci cums ances.
• I lis ed alien axa a e p esen on land ha is sold, pe mi s may be ans e ed o he new owne p o iding he new
owne con ac s he depa men (p e iously, he selle was obliga ed o no i y he buye o he p esence o alien and
in asi e species on he land and he buye had o apply o pe mi s); his does no apply o he sale o lis ed alien
axa.
• The heading ‘P ohibi ed alien and lis ed in asi e species di ec i es’ was emo ed. The obliga ion o keep a eco d o
di ec i es has been e ained bu mo ed o ano he egula ion.
• The e we e no changes o he annexu es.
The decision o emo e he p ohibi ed lis 1 was on he basis ha : a) all alien axa no legally p esen in Sou h A ica
equi e an impo pe mi ega dless o whe he hey a e lis ed as p ohibi ed; and b) he e idence as o why axa we e
included on he p ohibi ed lis was no a ailable. This does no a ec he ac i i ies ha a e p ohibi ed wi h ega d o
o he lis ed axa and he equi emen o apply o a pe mi o impo a axon no legally p esen in Sou h A ica s ill
emains.
O he han he p ohibi ed lis , he majo i y (almos 90%) o lis ings in 2020 we e as hey we e in 2016. The e we e
changes o he lis ings o 73 axa: ou axa we e added, all eshwa e ishes; 14 axa we e dele ed, mos ly bi ds; 20
axa p e iously p ohibi ed we e added o he lis s; o 19 plan axa he p o ision ha ‘s e ile cul i a s o hyb ids a e no
lis ed’ was emo ed, al hough his p o ision emains o 14 plan axa. Fo ull de ails o he changes see Wilson (2023)
and Supplemen a y Ma e ial S4.2. No ably, he cu en 2020 lis s s ill con ain se e al inconsis encies be ween he lis ed
name and he ecognised name as pe a ious axonomic backbones (261 ou o 560 axa see Table S4.3). In mos o
hese cases his is due o he lis ing o synonyms in he egula o y name, bu a leas wo egula ed axa a e lis ed unde
names ha a e no ecognised.
Reques s o change he lis ings o axa unde he NEM:BA A&IS Regula ions ha e, o da e, been deal wi h on an ad hoc
basis. A s anda dised o icial p ocess o publishing p oposals o e ise he egula o y lis s is unde de elopmen . To
suppo his, isk analyses a e p oduced in a consis en o ma using a isk analysis amewo k de eloped speci ically
o Sou h A ica (Kumschick e al. 2020b). These isk analyses a e e iewed by an independen scien i ic panel [ he Alien
Species Risk Analysis Re iew Panel (ASRARP); see Kumschick e al. (2020a) o mo e de ails] se up and un by SANBI on
DFFE’s behal . Howe e , he isk analyses hemsel es a e no ye in he public domain, and he amewo k is no ye an
o icial go e nmen documen .
Risk analyses on 68 axa we e e iewed by he ASRARP and p ocessed by SANBI be ween 2020 and 2022, his was a
signi ican inc ease on he p e ious pe iod ( isk analyses on 25 axa we e inalised in 2018 and 2019) (see Supplemen-
a y Ma e ial S4.4). O he 68 isk analyses, en we e on axa ha a e no lis ed, and o he emaining 58 lis ed axa, 33
sugges ed no change o he lis ing (changes o nomencla u e excep ed).
Te ms o e e ence o a go e nmen al decision-making body [The Risk Analysis Re iew Commi ee (RARC)] ha e been
ci cula ed o he RARC and he body had i s inaugu al mee ing on 2 Feb ua y 2023. The RARC, amongs o he unc ions,
in ends o e iew p oposals o change lis ings ecei ed by SANBI (based on ASRARP’s ecommenda ions). This p ocess
would acili a e egula e isions o he lis s as new in o ma ion becomes a ailable, as new eques s a e made and as
nomencla u e changes.
In e ms o pe mi s, 27 impo pe mi s we e issued by DFFE in 2020–2022 o 13 axa wi h some o hese o esea ch
and display pu poses; by compa ison 114 impo pe mi s we e issued on 25 axa in he pe iod 2015–2019 (no pe mi s
we e issued in 2014). This means hal he numbe o impo pe mi s we e g an ed pe yea in 2020–2022 compa ed
o he p eceding h ee yea s. This end was no seen o o he ypes o pe mi s. Du ing 2020–2022, 891 pe mi s we e
1In e p e ed he e as a lis o axa ha we e no legally in he coun y and ha may no be impo ed.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
issued (excluding impo pe mi s and pe mi s o esea ch, biocon ol o display pu poses ha can be issued o any
lis ed axon). A ~300 pe mi s pe yea his was sligh ly ewe ha he numbe issued in he p e ious yea s (an a e age
o ~350 pe yea o 2015–2019), bu he e was no no iceable decline du ing he COVID-19 lockdowns (Figu e S4.1).
No ably, o he 117 lis ed axa o which he e is p o ision o pe mi s o be issued o hei usage in he 2020 lis s (i.e.,
Ca ego y 2) 26 axa ha e ne e had a pe mi issued, a u he 39 axa ha e had i e o ewe pe mi s issued, bu he i e
mos equen ly pe mi ed axa ha e had o e 300 pe mi s issued each [in o de Kobus leche subsp. leche ( ed lechwe);
O eoch omis nilo icus (Nile ilapia); C enopha yngodon idella (g ass ca p and iploid g ass ca p); Dama dama ( allow
dee ); and Psi acula k ame i ( ose- inged pa akee )] (see Table S4.5; o he ull lis o pe mi s see Appendix 6). Pe mi s
o Ca ego y 2 ee species used in comme cial o es y a e subjec o p agma ic in e p e a ions o he egula ions,
which could ha e consequences o con aining he sp ead o he species used (Box 4.1).
The e we e no success ul p osecu ions unde he NEM:BA A&IS Regula ions in he pe iod co e ed by his epo . Two
cases wen o cou bu we e dismissed. In he i s case, he s a e ailed o p o e in en ion [ o he anspo o T a-
chemys sc ip a subsp. elegans ( ed-ea ed slide s)]. The second case in ol ed a pe shop ha had applied o a pe mi o
ade in Ca ego y 2 lis ed species, and hen sold hem be o e a pe mi was issued. The cou uled ha he DFFE had
aken an excessi ely long ime o issue he pe mi (i.e., exceeded he 60 days s ipula ed in he NEM:BA A&IS Regula ions
Sec ion 23 o each a decision a e ecei ing a isk assessmen epo ), hus un easonably p e en ing he ade om
conduc ing business and he case was dismissed.
The Na ional En i onmen al Laws Amendmen Ac , 2022 (NEMLAA) was assen ed by he P esiden in June 2022 and
came in o e ec on 30 June 2023. The Amendmen Ac amended, among o he Ac s, he NEM:BA. Unde he NEMLAA,
he NEM:BA has clea e de ini ions o he e ms ‘e adica e’ and ‘con ol’. I is also clea e om he ex ha in asi e
species mus be ei he e adica ed o con olled depending on wha is possible unde he ci cums ances, whe eas p es-
en ly, landowne s and o he ole-playe s a e equi ed o bo h e adica e and con ol in asi e species. Fu he mo e, he
NEM:BA no longe equi es landowne s o no i y compe en au ho i ies o he p esence o in asi e species on hei
land. The Minis e has he powe o speci y he ci cums ances unde which such no i ica ion mus be gi en o he
compe en au ho i y.
Melia azeda ach (© Zeynel Cebeci).
51
52
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
A na ional s a egy o biological in asions is unde de elopmen , led by he DFFE wi h inpu om o he depa men al
o icials and scien is s om SANBI. As o Oc obe 2023, a d a s a egy is ye o be made a ailable o public commen .
A Whi e Pape on he ‘Conse a ion and Sus ainable Use o Sou h A ica’s Biodi e si y’ was published on 14 June 2023.
Biological in asions we e e e ed o in one policy objec i e: ‘1.4. Iden i y and manage ha m ul, and po en ially ha m ul,
in asi e species, hei po en ial and exis ing in oduc ion pa hways and biological in asions.’ Fo de ails o he expec ed
ou pu s and ou comes see Supplemen a y Ma e ial S4.6. The Whi e Pape ep esen s an impo an s ep, bu as he
Whi e Pape does no co e all aspec s o biological in asions (e.g., he ocus is on biodi e si y a he han o he im-
pac s ha in asi e species can ha e on buil -in as uc u e and ood secu i y) i is unclea i i would nega e he need
o a policy speci ically on biological in asions. The Whi e Pape will be e alua ed in he nex epo . Howe e , Lukey
and Hall (2020) make i clea ha he law can be used o implemen policy. I a law does no make p o ision o a means
o implemen policy, i may be necessa y o in oduce new laws o egula ions. A Whi e Pape is a p ecu so o law, bu
he e is s ill no policy on biological in asions, so i is no immedia ely clea wha has in o med he d a ing o e e ences
o in asions in he Whi e Pape .
A an in e na ional le el, Sou h A ica is pa y o he Con en ion on Biological Di e si y (CBD) and, as such, he ecen ly
ag eed Kunming-Mon eal Global Biodi e si y F amewo k (GBF, Box 0.2), p o ides an impo an basis o de eloping
s a egic ac ion and de e mining moni o ing and epo ing ac ions.
4.2 Inpu – money spen
In o al, 14 o ganisa ions epo ed on money spen on biological in asions o 2020–2022, amoun ing o ~R1.5billion
(Table 4.1), alues epo ed he e a e adjus ed o 2020 alues o ZAR unless o he wise speci ied. A e ospec i e analysis
o he a ailable in o ma ion on spending by he DFFE’s Wo king o Wa e p og amme (W W) be ween 1999 and 2020
(Van Wilgen e al. 2022a) conside ed i e ca ego ies o spending: 1) e o s o con ol es ablished in asi e species; 2)
an incu sion esponse p og amme ha assessed and con olled alien plan axa ha we e ei he no lis ed o ha we e
e adica ion a ge s; 3) alue-added p ojec s; 4) high-al i ude si es; and 5) biological con ol esea ch and implemen a ion.
The o al amoun spen on hese i e in e en ions by he W W p og amme be ween 1999 and 2020 amoun ed o
ZAR7.1billion. The bulk o his (ZAR5.3 billion) was spen on he con ol o species ha we e well-es ablished. Annual
amoun s spen on con ac eams ose s eeply be ween 2000 and 2003, and hen s abilised un il 2010. Fu he inc eas-
es ollowed, peaking in 2015 and declining s eadily he ea e (see Supplemen a y Ma e ial S4.7). Some o he ela i e
decline in amoun spen on con ol p ojec s a e 2015 was due o unding being di e ed o alue-added p ojec s. Be-
ween 2015 and 2020, a ailable in o ma ion shows ha an a e age o ZAR62.7million was spen on biological con ol
esea ch and implemen a ion pe yea (2020 ZAR alues). O his, 87% was spen on loca ing, sc eening, eleasing and
moni o ing new biological con ol agen s, and 13% on mass- ea ing and elease p og ammes o es ablished agen s.
Ano he es ima e o he money spen was om an e o o consolida e in o ma ion om a ious sou ces using he
In aCos app oach (see Box 3.1). Fo Sou h A ica, he e was limi ed in o ma ion ega ding unding o p e-in oduc ion
managemen and no eco ds o cos s associa ed wi h o he p e-in asion e o s. To al managemen cos s om 1960 o
June 2023 amoun ed o ZAR9.6billion (exp essed in 2022 alues). This igu e is known o be an unde es ima e bu is
mode a ely highe han he es ima e o Van Wilgen e al. (2022a).
Jubase e al. (2021) su eyed he con ibu ions made by olun ee hack g oups in he Wes e n Cape. They b oadly
es ima ed ha hal o hese g oups clea ed nea ly 5300ha o land pe yea , wi h es ima ed labou con ibu ions o
ZAR5.1million pe yea when aligned wi h o mal s a e managemen cos es ima es. This was no included in he
abo e igu es. Maluleke e al. (2021) e ospec i ely es ima ed he ela i e he bicide cos -sa ing associa ed wi h he
use o biological con ol ins ead o chemical con ol. The s udy used a cos -bene i analysis amewo k wi h an 8% dis-
coun a e. The es ima ed cos o he biological con ol on ou in asi e aqua ic plan species [Azolla iliculoides (azolla),
My iophyllum aqua icum (pa o ’s ea he ), Pis ia s a io es (wa e le uce) and Sal inia moles a (Ka iba weed), in o de
o cos -e ec i eness], which a e unde comple e biological con ol in Sou h A ica, was abou ZAR7.8million. The es i-
ma ed cos o chemical con ol o achie e he same le el o con ol a ied be ween ZAR150million and ZAR1billion,
depending on he me hod o applica ion and numbe o ollow up ope a ions.
53
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table 4 .1 . Money epo ed as ha ing been spen on he managemen o biological in asions in Sou h A ica by di e en o ganisa ions be ween 2020 and 2022. The amoun s a e o alled o
h ee yea s, unadjus ed o in la ion. Inpu s om a ious o ganisa ions and many s akeholde s, pa icula ly in he p i a e sec o , we e no a ailable (and so he o e all igu e should be
iewed as a lowe es ima e). Howe e , i is also possible ha he e may be some double coun ing, as some o he money spen by implemen ing agencies may also ha e been epo ed
by he Depa men o Fo es y, Fishe ies and he En i onmen ’s (DFFE’s) Wo king o Wa e P og amme.
O ganisa ion Money spen on Money spen (ZAR) No es
Ag icul u al
Resea ch Council
Biological con ol esea ch 104495930 ZAR69700073 om he DFFE and ZAR34795857 om he ARC.
Bu alo Ci y (Eas
London)
P o ec ed a eas wi hin he municipal
bounda ies
9151000 This includes o he ac i i ies such as clea ing o ege a ion along oad
e ges.
Cape Na u e 31 p o ec ed a eas in he Wes e n Cape 9299189 Mos o his money came om he Wo king o Wa e p og amme and
so he e may be some double coun ing.
Cen e o Biological
Con ol, Rhodes
Uni e si y
Biological con ol esea ch and
implemen a ion
82000000 ZAR59million om Wo king o Wa e ; ZAR15million om he DST-NRF
ia he Sou h A ican Resea ch Chai s Ini ia i e; ZAR8million om o he
sou ces.
The bulk is spen a Rhodes Uni e si y, bu pa o he unding is
dis ibu ed o he uni e si ies o Cape Town, Wi wa e s and, KwaZulu-
Na al, Mpumalanga and Fo Ha e.
Ci y o Cape Town Managemen o in asi e species in
municipal p o ec ed a eas
Mass- ea ing o biological con ol agen s
106007412 The Ci y o Cape Town is he only municipali y ha epo ed ha hey
we e ac i ely con olling he polyphagous sho -hole bo e (Euwallacea
o nica us).
Ci y o Eku huleni
(Gau eng)
Managemen o aqua ic ecosys ems 17700000 Funding has been expended mos ly on Pon ede ia c assipes (wa e
hyacin h), A undo donax (gian eed) and Nymphaea mexicana (yellow
wa e lily) in ading aqua ic ecosys ems.
Depa men o
Ag icul u e, Land
Re o m and Ru al
De elopmen
Responsible o Conse a ion o
Ag icul u al Resou ces Ac (CARA) and
o he legisla ion
Main ains a p esence a all bo de pos s
No es ima e
a ailable
The expendi u e on hese ac i i ies was eques ed om DALRRD bu no
inpu was ecei ed.
DFFE animal con ol
p ojec s
Con ol o in asi e animals No es ima e
a ailable
The expendi u e on hese ac i i ies was eques ed om DFFE bu no
inpu was ecei ed.
54
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
O ganisa ion Money spen on Money spen (ZAR) No es
DFFE Biosecu i y Moni o ing ac i i ies aimed a
in e cep ion o alien species a OR Tambo
In e na ional Ai po
13820241 The igu e epo ed he e does no co e he cos s o all o he
biosecu i y ac i i ies unde aken by he DFFE, no does i include
depa men al o e heads.
DFFE high al i ude
eams
Specially ained eams deployed o
con ol in asi e plan s in inaccessible o
moun ainous e ain
255298699 Budge ed amoun o inancial yea s. The DFFE epo ed an amoun o
ZAR208237112 and 22.6% was added o accoun o o e heads (Van
Wilgen e al. 2022a).
DFFE Na u al
Resou ce
Managemen
p og ammes
(Wo king o Wa e )
App oxima ely 250 p ojec s o con ol
es ablished in asi e plan s ac oss all nine
p o inces
470972650 This co e s he pe iod 1 Janua y 2020 o 30 Ap il 2022. The DFFE was
no able o supply da a o he pe iod 1 May o 31 Decembe 2022. The
DFFE epo ed an amoun o ZAR384153875 and 22.6% was added o
accoun o o e heads (Van Wilgen e al. 2022a).
Funding (including o e heads) can be b oken down in o:
ZAR413206893 o widesp ead alien plan s (See Table 4.2 o
a b eakdown by he mos cos ly species); ZAR47812384 o
e adica ion a ge s; ZAR37336449 o na i e bush enc oache s; and
ZAR10475934 o alien aqua ic weeds.
DFFE alue added
indus ies
Es ablishmen and ope a ion o ac o ies
in ended o p oduce a ange o p oduc s
wi h biomass sou ced om alien plan
con ol ope a ions
237223158 Budge ed amoun o inancial yea s. The DFFE epo ed an amoun o
ZAR193493604 and 22.6% was added o accoun o o e heads (Van
Wilgen e al. 2022a).
Gau eng p o incial
ese es (No h)
Th ee p o ec ed a eas in he no h o
Gau eng
6000 Only includes cos s o he bicide and a pai o scisso s, s a ime no
included.
Gau eng p o incial
ese es (Sou h)
Th ee p o ec ed a eas in he sou h o
Gau eng
2300000
In asi e Fish Species
Managemen (IFSM)
Con ol o Cyp inus ca pio (common ca p)
in G oen lei Lake, Wes e n Cape.
450000 IFSM is an NGO in he Ga den Rou e. Amoun spen be ween 2018
and 2022 was ZAR750000 (es ima e supplied by he di ec o , Johnny
Snyman). Assuming an equal amoun spen each yea , he es ima e o
2020 o 2022 is ZAR450000.
Table 4 .1 . (Con inued) Money epo ed as ha ing been spen on he managemen o biological in asions in Sou h A ica by di e en o ganisa ions be ween 2020 and 2022. The amoun s
a e o alled o h ee yea s, unadjus ed o in la ion. Inpu s om a ious o ganisa ions and many s akeholde s, pa icula ly in he p i a e sec o , ha e no been included (and so he o e all
igu e should be iewed as a lowe es ima e). Howe e , i is also possible ha he e may be some double coun ing, as some o he money spen by implemen ing agencies may also ha e
been epo ed by he Depa men o Fo es y, Fishe ies and he En i onmen ’s (DFFE’s) Wo king o Wa e P og amme.
55
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
O ganisa ion Money spen on Money spen (ZAR) No es
Sou h A ican
Na ional
Biodi e si y Ins i u e
P epa a ion o s a us epo s, isk
analyses, incu sion esponse, axonomy,
esea ch, and human capaci y
de elopmen (placemen o in e ns)
145454000 Money ob ained on con ac om DFFE.
Sou h A ican
Na ional Pa ks
22 na ional pa ks ac oss Sou h A ica and
ou side o pa ks in bu e zones
3985260 SANPa ks epo ed an amoun o ZAR199263000, bu only 2% o his
came om he SANPa ks budge , he es om DFFE.
The G ea e Cape
Town Wa e Fund
Ca chmen s o he Be g and
Theewa e skloo dams, and A lan is
aqui e , Wes e n Cape
~100000000 Es ima ed amoun p o ided by he p ojec manage .
Volun ee g oups 52 olun ee g oups om he Wes e n
Cape who clea in asi e plan s
15318723 Da a om Jubase e al. (2021). This is he cu en cos o clea he
equi alen a ea ha has been clea ed by olun ee g oups.
Wo ld Wide Fund o
Na u e Sou h A ica
(WWF-SA)
11 S a egic Wa e Sou ce A eas in he
Wes e n Cape ynbos ca chmen s and
in he Eas e n Cape and KwaZulu-Na al
D akensbe g.
26603201 Some o his money may be included in he G ea e Cape Town Wa e
Fund es ima e.
Table 4 .1 . (Con inued) Money epo ed as ha ing been spen on he managemen o biological in asions in Sou h A ica by di e en o ganisa ions be ween 2020 and 2022. The amoun s
a e o alled o h ee yea s, unadjus ed o in la ion. Inpu s om a ious o ganisa ions and many s akeholde s, pa icula ly in he p i a e sec o , ha e no been included (and so he o e all
igu e should be iewed as a lowe es ima e). Howe e , i is also possible ha he e may be some double coun ing, as some o he money spen by implemen ing agencies may also ha e
been epo ed by he Depa men o Fo es y, Fishe ies and he En i onmen ’s (DFFE’s) Wo king o Wa e P og amme.
56
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
4.3 Inpu – planning co e age
Pa hway managemen plans: As epo ed in he p e ious epo , no o mally app o ed managemen plans o pa hways
ha e been de eloped by DFFE, and he e is no equi emen o pa hway managemen plans unde he NEM:BA A&IS
Regula ions. Howe e , managemen is in place o 39 o 44 pa hways. The e o e, i is assumed ha plans a e in place
o hose pa hways, hough no eco ds o he plans being o mally app o ed we e a ailable. In addi ion, ballas wa e
managemen plans ha e been de eloped, bu no implemen ed, hus 40 pa hways a e assumed o ha e plans in place
(see Supplemen a y Ma e ial S4.8).
Species managemen plans: The NEM:BA equi es [Sec ion 75(4)] he Minis e o ensu e he coo dina ion and implemen-
a ion o plans (called p og ammes in he Ac ) o he p e en ion, con ol and e adica ion o in asi e species. No plans
ha e been o mally adop ed, al hough, as epo ed p e iously, plans ha e been p epa ed o wo species [Pa henium
hys e opho us (pa henium) and Campuloclinium mac ocephalum (pom-pom weed)], wo gene a [Acacia (wa les) and
Nel uma (p e iously P osopis, mesqui e)], and one amily [Cac aceae (cac i)] o in asi e plan s. In addi ion, 22 plans
ha e been de eloped o species a ge ed o , o conside ed o , na ionwide e adica ion. O he 22 species manage-
men plans, 12 we e sco ed as adequa e, eigh as pa ially adequa e and wo as inadequa e. Mos (15) o hese species
a e Ca ego y 1a, he o he se en a e no cu en ly lis ed (see Supplemen a y Ma e ial S4.9 o how he plans we e
sco ed and Table S4.6 o he lis o axa).
Si e managemen plans: In e ms o he NEM:BA A&IS Regula ions he esponsibili y o d awing up managemen
plans o si es lies wi h indi idual landowne s (s a e o p i a e), because hey a e esponsible by law o he con ol
o lis ed alien axa on hei land. A da abase has been de eloped o ack planning co e age o si es (see Table 4.3
and Supplemen a y Ma e ial S4.10). All plans submi ed o SANBI o he i s h ee s a us epo s we e cap u ed in o
his da abase.
To da e, 99 plans co e ing 7.9millionha ha e been submi ed o SANBI o inclusion in his and p e ious epo s.
Assuming he e is no spa ial o e lap be ween plans, his amoun s o 19.5millionha o 40.5% o he es ima ed a ea
co e ed by in asions in Sou h A ica (Van Wilgen e al. 2022a). O hese, 67 plans a e conside ed o be cu en and 32
ha e lapsed and a e assumed no o ha e been upda ed. The e o e, i is assumed ha cu en plans co e 5.3millionha
Table 4 .2 . Money spen clea ing selec ed in asi e plan s in Sou h A ica by he Wo king o Wa e p og amme. This is o he pe iod
2020 o he end o Ap il 2022. Values include a 22.6% o e head. Spending on hese axa ep esen abou wo hi ds o all he
money disbu sed.
Taxon Money spen (ZAR) % o o al cos
Acacia mea nsii (black wa le) 88634536 18.8
Lan ana cama a (lan ana) 55549985 11.8
Acacia saligna (Po Jackson willow) 32342218 6.9
Nel uma species and hyb ids (mesqui e) 28605969 6.1
Acacia melanoxylon (Aus alian blackwood) 22182801 4.7
Acacia dealba a (sil e wa le) 21189774 4.5
Rubus cunei olius (Ame ican b amble) 13391654 2.8
Pinus pinas e (clus e pine) 13204338 2.8
Ch omolaena odo a a ( i id weed) 12114313 2.6
Acacia cyclops ( ooik ans) 9079521 1.9
Psidium guaja a (and possibly o he Psidium spp.) (gua a) 8307475 1.8
Eucalyp us camaldulensis (and possibly o he Eucalyp us spp.) ( i e ed gum) 8144657 1.7
57
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
O ganisa ion Si es o be managed A ea co e ed
by plans (ha)
Adequacy o plans No es
Depa men o
Fo es y, Fishe ies
and he En i onmen
Na u al Resou ce
Managemen
p og ammes (Wo king
o Wa e )
Wo king o Wa e has many p ojec s
ac oss all nine p o inces
0 NA No plans we e submi ed. Wo king o Wa e does
no p epa e managemen plans as his is he
esponsibili y o indi idual landowne s (p i a e
and s a e) o who hey p o ide suppo . Howe e ,
Wo king o Wa e has unded he de elopmen o
six demons a ion ‘managemen uni con ol plans’
(MUCPs)1 o he uppe ca chmen o he Be g Ri e ;
Cape Na u e’s Wa e al Cen e; he ca chmen s o
he Holsloo , Keu booms, and Ka a a a i e s; and
he G ea e Simonsbe g Conse ancy. They will be
assessed once hey a e ecei ed.
Cape Na u e P o ec ed a eas in he Wes e n Cape
P o ince
607142 Adequa e (486476ha)
Pa ially adequa e
(120666ha)
19 plans co e ing 31 p o ec ed a eas we e
submi ed by Cape Na u e; some plans co e mo e
han one p o ec ed a ea ‘complex’. In addi ion,
demons a ion ‘managemen uni con ol plans’
(see abo e) ha e been p epa ed o he uppe
ca chmen o he Be g Ri e and he Wa e al
complex, bo h managed by Cape Na u e.
Sou h A ican Na ional
Pa ks
Na ional Pa ks in Sou h A ica 3990856 Adequa e (3755927ha)
Pa ially adequa e
(214514ha)
Inadequa e (20415ha)
Sou h A ican Na ional Pa ks p o ided si e
managemen plans o 18 ou o 22 na ional pa ks.
Plans o he emaining na ional pa ks a e being
compiled.
Gau eng p o incial
ese es
Six p o ec ed a eas wi hin Gau eng 25000 Pa ially adequa e Plans we e p epa ed o he Abe Bailey, Alice
Glöckne , Leeuw on ein, Roodeplaa Dam,
Suike bos and Na u e Rese es, and he Ma ie ale
Bi d Sanc ua y.
1The MUCP so wa e can be downloaded om a si e main ained by And ew Wannenbu gh (awannenbu gh@d e.go .za) o he Ope a ional Suppo and Planning Di ec o a e in he Na u al Resou ce Managemen
p og ammes o he Depa men o Fo es y, Fishe ies and he En i onmen (h ps://si es.google.com/si e/w wplanning/moni o ingande alua ion).
Table 4 .3 . Managemen plans o biological in asions a pa icula si es. In cases whe e no plans we e submi ed o SANBI he a ea co e ed by he plans is conside ed o be ze o.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
species, 12% (nine species) we e lis ed unde he NEM:BA A&IS Regula ions (Niemann e al. 2022). In e es ingly, a su -
ey o pe shops a ound he coun y showed ha mos esponden s (68%) we e awa e o he NEM:BA A&IS Regula ions,
bu 71% we e agains he egula ion o he ade despi e 58% admi ing o losing o ganisms h ough escapes (Shi am-
bu e al. 2022a). Un o una ely, mos pe ade s (83%) we e no egis e ed wi h he associa ion o pe ade s, making
i di icul o moni o he ade (Shi ambu e al. 2022a).
4.8 Ou come – e ec i eness o species ea men s
Fo almos wo hi ds o he species ha we e epo ed o ha e been ea ed o e he 2020–2022 pe iod, he e ec i e-
ness o ea men s could no be e alua ed (Table 4.6). The e ec i eness o species ea men s could, in mos cases,
only be sco ed o plan o in e eb a e pes species unde biological con ol, wi h con ol sco ed as pe manen in
cases whe e biological con ol was assessed as comple e (P insloo & Uys 2015; Zacha iades 2021, see Supplemen a y
Ma e ial S4.15 o ull de ails).
Table 4 .6 . The numbe o in asi e species in di e en ca ego ies o con ol e ec i eness ha we e subjec ed o managemen in e -
en ions be ween 2020 and 2022.
G oup Ca ego y o con ol e ec i eness To al
Pe manen E ec i e Pa ially e ec i e Ine ec i e No e alua ed
Plan s 12 34 10 9 170 235
Bi ds 0 1 0 1 1 3
F eshwa e ish 0 0 1 1 0 2
Mammals 0 1 0 0 0 1
Insec s 5 5 12 2 52 76
Molluscs 0 0 1 0 0 1
Amphibians 0 0 0 0 1 1
To al 17 41 24 13 224 319
Neph olepis exal a a (© Fo es and Kim S a ).
64
65
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
In e ms o speci ic ou comes, Mo i soe e al. (2020) epo ed ha biological con ol o he alien aqua ic plan Sal inia
moles a (Ka iba weed) by he in oduced wee il Cy obagous sal iniae acili a ed he eco e y o epili hic algae and
aqua ic mac oin e eb a e communi ies. Coe zee e al. (2022) epo ed ha eleases o he biological con ol agen
Megamelus scu ella is a Ha beespoo Dam esul ed in a educ ion in co e o Pon ede ia c assipes (wa e hyacin h)
om o e 37% o less han 6% o e wo consecu i e yea s (Box 4.3). Cas añeda e al. (2020) moni o ed na i e ishes
o e i e yea s a e he e adica ion o in asi e Mic op e us dolomieu (smallmou h bass) om he Rondega Ri e in he
Wes e n Cape, and concluded ha he na i e ish communi y had eco e ed, bu ha he emo al o smallmou h bass
was no su icien o ull eco e y o all species (i.e., o he h ea s emained). Addi ional conse a ion measu es would
be needed o secu e he popula ion s abili y and pe sis ence o endange ed ishes.
4.9 Ou come – e ec i eness o si e ea men s
The ongoing sca ci y o o mal sys ems ha moni o he ou comes o si e ea men s emains an obs acle o he as-
sessmen o he e ec i eness o ea men s. The Wo king o Wa e p og amme, which p o ides ~80% o unding o
alien species con ol measu es in he coun y, does no compile managemen plans no moni o he ou comes o hei
unding. This is because he legal obliga ion o plan and moni o lies wi h indi idual landowne s, who a e suppo ed
by Wo king o Wa e , and no wi h Wo king o Wa e i sel . Wo king o Wa e ’s pe o mance is measu ed in e ms o
employmen c ea ed, money spen (inpu s), and a ea clea ed (an ou pu ), bu no in e ms o changes in he ex en o
in asions o es o a ion o ecosys em unc ion (ou comes). I he e o e plans o spend money, employ people and clea
si es, bu does no explici ly plan o achie e con ol.
No ecen esea ch epo s o publica ions we e ound ha ha e assessed he e ec i eness o si e ea men s. None-
heless, Cape Na u e assessed he e ec i eness o alien plan con ol measu es on 31 p o ec ed a ea clus e s, based
on es ima es o he co e o alien plan s as: e ec i e o i e p o ec ed a ea clus e s; pa ially e ec i e o 20 clus e s;
ine ec i e o h ee clus e s; and unknown o h ee clus e s (see Supplemen a y Ma e ial S4.16 o u he de ails).
No ably e ec i eness was exp essed in e ms o an inc ease o dec ease in he co e o in asi e plan s, and no in e ms
o he eco e y o biodi e si y and ecosys em unc ioning in he a ge ecosys em.
Kee e al. (2022) assessed he le el o compliance wi h he NEM:BA A&IS Regula ions by compa ing he numbe o lis -
ed alien plan s species in 36 ‘camps’ (s a illages, ange ou pos s and ou is a eas) in he K uge Na ional Pa k in 2001
wi h numbe s in 2020 (no ing he egula ions i s came in o e ec in 2014). The numbe o alien plan species almos
doubled a e he i s su ey ( om 231 o 438) likely due o a mo e sys ema ic sea ch by ained bo anis s. Despi e his
o e all inc ease, he e we e 38% ewe lis ed alien plan species ound du ing he 2020 su ey and he numbe o lis ed
aliens ound pe camp declined by 56%. The conclusion was ha he egula ions p o ided clea guidance o conse a-
ion manage s, and ha he e we e p omising signs o educ ions in a ge ed alien plan species.
O conce n is ha ew clea ing ope a ions explici ly link h ough o he biodi e si y ou comes, in pa icula as some
e idence sugges s ha ac i e es o a ion is necessa y a e he emo al o in asi e plan s. The cos s o ac i e es o-
a ion in e en ions migh , in some cases, be economically jus i iable, bu he cos o ully es o ing ecosys em s uc-
u e, unc ioning and composi ion in highly deg aded ecosys ems has a ely been deemed economically jus i iable in
Sou h A ica (Holmes e al. 2020; Van Wilgen e al. 2022a). Gene ally, go e nmen -suppo ed con ol ope a ions ha e
no included es o a ion e o s, a leas in pa because he e is li le o no unding o implemen ing ac i e es o a ion
p ojec s a he necessa y scale – mos si es a e le o passi e es o a ion (Van Wilgen e al. 2022a).
66
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Box 4.1. The egula ion o in asi e species used in comme cial imbe plan a ions
One o he majo sou ces o plan in asions in Sou h A ica is comme cial imbe plan a ions. This is ongoing
despi e he o es y sec o being hea ily egula ed. Se e al ee species used in plan a ions a e lis ed unde he
NEM:BA A&IS Regula ions, and a pe mi is equi ed o es ablish a new plan a ion o o ex end an exis ing plan-
a ion in ol ing hose species [see Appendix 6 o he pe mi s issued pe axon and Wilson (2023) o de ails o
he lis ed axa]. Be o e a pe mi o es ic ed ac i i ies in ol ing a lis ed alien species is issued, applican s mus
demons a e ha adequa e measu es will be aken o p e en sp ead. Impo an ly, he Minis e o Fo es y, Fish-
e ies and he En i onmen has, in e ms o he NEM:BA, exemp ed exis ing plan a ions – hose plan a ions ha
we e es ablished and ope a ional be o e 1 Augus 2014, when he A&IS Regula ions i s came in o ope a ion –
om he equi emen o ob ain a pe mi in e ms o he NEM:BA and he A&IS Regula ions.
Pe mi s issued unde he NEM:BA a e no he only egula o y ool ele an o plan a ions. Addi ional egula o y
equi emen s o plan a ion o es y include:
• A wa e use licence (WUL) in e ms o he Na ional Wa e Ac , 1998 (Ac No. 36 o 1998) (NWA) o any ‘s eam
low educ ion ac i i ies’, which includes he use o land o comme cial a o es a ion.
• En i onmen al au ho isa ion o a plan a ion exceeding 300ha in ex en in e ms o he Na ional En i onmen-
al Managemen Ac , 1998 (Ac No. 107 o 1998) (NEMA).
• A licence o es ablish o ecommission a plan a ion in a S a e Fo es in e ms o he Na ional Fo es s Ac , 1998
(Ac No. 84 o 1994) (NFA).
• Consen om he ele an au ho i ies o g ow speci ied in asi e plan species in a eas o he han hose iden i-
ied in WULs o o he speci ically dema ca ed a eas in e ms o he Conse a ion o Ag icul u al Resou ces Ac ,
1983 (Ac No. 43 o 1983) (CARA).
The addi ional egula o y app o als abo e may be subjec o app op ia e condi ions, bu hey do no equi e
he ope a o s o p e en he sp ead o he in asi e species beyond he app o ed a ea. This may well become
p oblema ic in he case o exis ing plan a ions ( hose es ablished be o e 1 Augus 2014) o which pe mi s issued
unde he A&IS Regula ions a e no equi ed.
While he e is a gene al du y o e adica e o con ol axa lis ed unde he A&IS Regula ions, ha esponsibili y only
applies o owne s o land on which he in asi e species is p esen . Comme cial o es y companies ha ope a e
exis ing comme cial plan a ions ( hose es ablished be o e 1 Augus 2014) in S a e Fo es s (owned by he S a e)
he e o e do no ha e ha gene al du y o ca e. In hose ins ances, he S a e bea s he du y o ca e. E iden ia y
p oo ha in asi e plan s ha e sp ead om a pa icula p ope y is o en also di icul o ob ain, especially whe e
he e a e mul iple plan a ions in an a ea. Thus, a subs an ial a ea o comme cial o es y emains as an un egula -
ed seed sou ce o ein ading adjacen a eas ha ha e been clea ed.
Box Figu e 4 .1 . Fo es y plan a-
ions (backg ound) a e a majo
and ongoing sou ce o p opa-
gules o in ading adjacen a -
eas ( o eg ound). Pho og aph:
© B ian an Wilgen.
67
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Box 4.2. The G ea e Cape Town Wa e Fund
Conce n abou he g owing impac o in asi e ees on Cape Town’s wa e supplies led o he es ablishmen o
he G ea e Cape Town Wa e Fund in 2018. The und was based on a easibili y s udy (Tu pie e al. 2017) and busi-
ness case (S a o d e al. 2018), which showed ha clea ing Cape Town’s p io i y wa e ca chmen s by emo ing
in asi e ees could gene a e annual wa e gains o 50billionli es wi hin i e yea s – equi alen o one-six h o
he ci y’s cu en supply needs. These gains could double o 100billionli es annually wi hin 30 yea s. This ap-
p oach was es ima ed o be signi ican ly mo e cos -e ec i e han o he wa e augmen a ion solu ions.
The und is co-o dina ed by he Na u e Conse ancy (a US-based NGO) and is a pa ne ship be ween na ional,
p o incial, and local go e nmen depa men s, co po a e sponso s (including Nedbank, Coca-Cola, AB-InBe , and
REMGRO), and NGOs ( he Na u e Conse ancy and he Sou h A ican b anch o he Wo ld Wide Fund o Na u e).
The und has a ge ed he ca chmen s o Cape Town’s majo supply dams a Theewa e skloo , Be g i e , Wemme -
shoek and S eenb as, as well as he echa ge basin o he A lan is aqui e . The und has a blended unding model
and a 30-yea ime ho izon. I has aised ZAR182million o he equi ed ZAR372million in unding o i s i s
six yea s o ope a ion, wi h con ibu ions om co po a e sponso s (28% o unds aised o da e), philan h opic
indi iduals and ounda ions (46%), and he Ci y o Cape Town (26%).
The und’s key objec i e is o educe he co e o ma u e alien ees o below 5% wi hin 30 yea s and es o e a
co e o na u al ege a ion whe e possible. The und has al eady spen ~ZAR100million and is now hal way o
achie ing i s ini ial six-yea a ge o clea ing 55300ha. Abou 75% o he clea ed a ea was uppe ca chmen s
in aded by alien pine (genus Pinus) ees. The und uses a cus om-buil decision suppo sys em o guide i s ope -
a ions. The sys em acks all clea ing and ollow-up ope a ions and p io i ises si es o in e en ions. In e en ions
a e also egula ly moni o ed o assess he e ec i eness o ope a ions, as well as ecosys em eco e y and social
bene i s gene a ed.
The implemen a ion o his und, which a ge s ca e ully p io i ised a eas, and includes he necessa y compo-
nen s o planning and moni o ing, p o ides an excep ional example o he implemen a ion o bes p ac ice in he
con ol o plan in asions wi h clea goals and ime ames. I is also unique in ha i ob ains unding om mul iple
sou ces and p o ides a model o he planning o simila in e en ions elsewhe e.
Box Figu e 4 .2 . Wo ke s om he G ea e Cape Town Wa e Fund emo ing in asi e pine ees om he ca chmen o he
Theewa e skloo Dam ( isible in he igh -hand backg ound). Pho og aph: © Louise S a o d.
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
68
Box 4.3. Success ul biological con ol o wa e hyacin h on a eu ophic sub opical wa e body
Pon ede ia c assipes (wa e hyacin h) has caused ‘Majo ’ impac s wo ldwide by co e ing wa e bodies in ege a-
ion, educing oxygen le els in he wa e , and he eby al e ing he di e si y o eshwa e ben hic communi ies
and impac ing he p o ision o ecosys em se ices (including oppo uni ies o ishing, swimming and boa ing).
Biological con ol has been highly success ul in opical a eas, bu in mo e sub opical, eu ophic wa e s biologi-
cal con ol has been less success ul, especially whe e coole win e clima es p e ail.
In Sou h A ica au ho i ies ha e eso ed, a conside able expense, o sp aying he bicides om ai c a and boa s.
Howe e , plan s a e able o e-colonise hese sp ayed a eas apidly, empo a ily escaping biological con ol. This
means ha sp aying ope a ions need o be cons an ly epea ed, adding ano he sou ce o chemical pollu ion o
he wa e s.
A ela i ely new addi ion o he sui e o biological con ol agen s was Megamelus scu ella is, which was i s e-
leased in Sou h A ica in 2013. This insec was p omising because i esponds well o mass ea ing, ep oduces
apidly, and eco e s quickly a e pe iods o coole empe a u es. In addi ion, i can be excep ionally damaging
o wa e hyacin h. Insec s we e mass- ea ed and eleased in a s and-alone in e en ion on Ha beespoo Dam in
2018 in he absence o he bicide ea men s.
Following equen inunda i e eleases o he agen s (i.e., many eleases each o a la ge numbe o insec s), Coe -
zee e al. (2022) epo ed ha wa e hyacin h co e was educed om o e 37% o less han 6% o e wo consecu-
i e yea s (Box Figu e 4.3). The ecommenda ion was o elease he insec s o en and in high numbe s o inunda e
and o e whelm he wa e hyacin h and o achie e con ol a a ac ion o he cos o he bicide applica ions. This
ep esen s a majo b eak h ough in he con ol o wa e hyacin h in Sou h A ica (and po en ially in o he sub-
opical and empe a e eu ophic wa e bodies wo ldwide).
Box Figu e 4 .3 . Declines in he co e o Pon ede ia c assipes (wa e hyacin h) be ween: A, Janua y 2017 and B, Feb ua y 2020
due o biocon ol by Megamelus scu ella is. Wa e hyacin h is he b igh g een agains he black wa e in he sa elli e imag-
es. This con ol happened in he absence o he bicide applica ions. Figu e om Coe zee e al. (2022).
A B
Ligus um ulga e (© K zysz o Golik).
69
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
4.10 T ends in in e en ions indica o s
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4. Le el o
success in
managing
in asions
no assessed ↗This indic o canno be calcula ed as he e
a e e y ew da a on he e ec i eness o
con ol o in asions a speci ic si es.
Making a easonably accu a e assessmen o he o e all
success o managing in asions emains challenging
due o he pauci y o s a ed goals in managemen plans
agains which o assess p og ess, as well as he sca ci y
o ac i i ies o egula ly moni o p og ess owa ds
goals. These issues need o be u gen ly add essed
because wi hou hem e ec i eness canno be known,
managemen canno be adap i e, and he impac s and
cos s o in asions will con inue o ise.
The d a na ional s a egy and ac ion plan on biological
in asions migh help add ess hese issues explici ly.
4.1 Quali y o
egula o y
amewo k
→Medium ↗The amendmen s o he NEM:BA and he
A&IS Regula ions and Lis s ha e imp o ed
he egula o y egime sligh ly. The law
e o m has cla i ied some concep s and
he changes may help go e nmen
o p io i ise sca ce law en o cemen
in e en ions. Howe e , he e is s ill an
absence o a comp ehensi e s a egy o
guide implemen a ion o he egula ions
and lack o lexibili y in he egula o y
egime.
A d a na ional s a egy on biological
in asions has been de eloped bu no , as
ye , sen o public commen .
The ecen publica ion o he Whi e Pape on he
‘Conse a ion and Sus ainable Use o Sou h A ica’s
Biodi e si y’ is an indica ion ha DFFE plans o amend
he NEM:BA in he nea u u e. Howe e , he Whi e
Pape does no add ess he p oblems wi h he cu en
egula o y egime and does no comp ehensi ely
add ess issues a ound biological in asions.
The de elopmen and implemen a ion o a na ional
s a egy o biological in asions has he po en ial o be a
miles one in he managemen o biological in asions in
Sou h A ica.
The de elopmen and implemen a ion o a p ocess o
egula ly and anspa en ly upda e he egula o y lis s
in o med by he bes a ailable scien i ic e idence is
p omising.
→ no change; ↗ an inc ease; ↘ a dec ease.
70
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.2 Money spen ↘Low ↗1An es ima ed ZAR1.5billion was spen
be ween 2020 and 2022. This is an
unde es ima e as no all go e nmen
en i ies, NGOs o he p i a e sec o ha e
p o ided es ima es. The amoun spen has
been declining in eal e ms since 2015
(Van Wilgen e al. 2022a).
Go e nmen ’s abili y o und he con ol o biological
in asions has been educed due o ad e se economic
condi ions ha ha e p e ailed o e he pas ew yea s.
La ge inc eases in unding a e unlikely in he nea u u e.
The G ea e Cape Town Wa e Fund may p o ide a new
model o und aising (Box 4.2).
4.3 Planning
co e age
→Medium ↗Pa hways: 40 o he 44 pa hways a e
assumed o ha e managemen plans in
place, bu hese ha e no necessa ily been
o malised. No o mal plans ha e been
de eloped by DFFE and he e is no legal
equi emen o do so. The e has been no
change since he p e ious epo .
Species: 22 (15 lis ed and 7 unlis ed)
species ha e managemen plans in
place. O hese plans, 13 we e sco ed as
adequa e, 8 as pa ially adequa e, and
2 as inadequa e. This is 2.8% o he 560
lis ed alien axa. None o hese plans
ha e been o mally adop ed, no is he
p ocess o o mal adop ion clea , al hough
landowne s a e equi ed by law o con ol
species on hei land in acco dance wi h
such plans, should hey exis [ he NEM:BA
Sec ions 75(4) and 75(5)].
The e is s ill a need o iden i y p io i y pa hways and
de elop and o mally adop plans o suppo he
managemen o hose pa hways.
The e is a simila lack o o mal planning p ocesses o
add ess species and si es. Wi hou such planning i will
no be possible o managemen o be s a egic and
di icul o managemen o be adap i e.
→ no change; ↗ an inc ease; ↘ a dec ease.
1Technically he end should be owa ds an es ima e o he money equi ed o cos -e ec i ely add ess he p oblem (e.g., so ha e u ns on in es men o addi ional spending on a e age end up as ze o). Howe e ,
es ima es o he money equi ed o b ing biological in asions unde e ec i e con ol sugges his igu e is oughly 4.6 imes g ea e han cu en budge s (Van Wilgen e al. 2016). A p esen , i spen s a egically,
he e a e signi ican e u ns on in es men o be had by spending money on con olling in asions, and he e o e he desi ed end is o an inc ease in he money spen .
71
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
Si es: Cu en managemen plans co e 7.9
million ha (all o which is no necessa ily
in aded). Planning co e age appea s
o ha e inc eased signi ican ly om he
p e ious epo , p obably because exis ing
plans we e no p e iously submi ed o
assessmen , no ing ha many mo e plans
likely exis bu we e s ill no ecei ed. Si e
plans ha we e esubmi ed we e assessed
as ha ing imp o ed
4.4 Pa hways
ea ed
→Low ↗All pa hways h ough which alien
o ganisms can be in oduced equi e
managemen , and cu en ly 39 o he
44 pa hways (89%) a e managed o
some ex en . Many o he pa hways (19
pa hways) ha a e managed a e pa ially
managed, bu mos (20 pa hways) ha e
comple e managemen . The e has been no
change since 2019.
The es ablishmen o he Bo de Managemen Au ho i y
should esul in mo e co-o dina ed managemen o
pa hways. The implemen a ion o he ballas wa e
managemen bill would also imp o e he si ua ion.
Howe e , unless p io i y pa hways a e iden i ied, and
pa hway- ocused managemen o hose pa hways is
implemen ed, ha m ul in asi e species will con inue o
be in oduced.
4.5 Species
ea ed
→Low ↗320 alien axa we e subjec ed o con ol
measu es du ing 2020–2022, o which 58%
we e lis ed. Mos e o is di ec ed owa ds
widesp ead o damaging axa o owa ds
axa ha a e po en ial e adica ion a ge s.
Se e al in asi e axa a e expanding hei anges apidly,
so capaci y o deal wi h all axa will be u he educed.
The d a na ional s a egy on biological in asions, in
conce wi h he GBF (Box 0.2) is likely o incen i ise
g ea e p io i isa ion o con ol e o s agains he mos
damaging lis ed alien axa and hose ha p esen he
g ea es u u e h ea s.
→ no change; ↗ an inc ease; ↘ a dec ease.
72
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.6 Si es ea ed no assessed ↗The a ea ha has been ea ed in 2020–
2022 is es ima ed o be 2003km2, his
includes all land pa cels ha ha e been
wo ked on by public wo ks alien plan
con ol eams. The es ima ed o al in aded
a ea in Sou h A ica is 194943km2, so
con ol ope a ions ha e he e o e eached
jus o e 1% o he es ima ed in aded
a ea. A ecen s udy es ima ed ha con ol
ope a ions be ween 1998 and 2020 had
eached 14% o he es ima ed a ea o e
22 yea s (Van Wilgen e al. 2022a). Because
con ol ope a ions a e no ollowed up
e e y yea , i may be necessa y o examine
he ex en o ea men o e longe
pe iods. The e a e subs an ial unce ain ies
ega ding he es ima ed ex en o in asion.
Con ol also o en does no co e he ull
a ea mapped as ha ing ecei ed con ol,
so he 1% (and he 14%) a e p obably
o e es ima es.
I is expec ed ha he a ea in aded in Sou h A ica will
inc ease. P ocesses a e, howe e , in place o ensu e
g ea e p io i isa ion o con ol e o s o ensu e p io i y
si es a e clea ed and kep clea (c . ou look o species
ea ed).
4.7 E ec i eness
o pa hway
ea men s
→Low ↗The e has been no change o he es ima ed
e ec i eness o pa hway managemen o
mos pa hways. Fo one pa hway, eleases
o conse a ion, he e ec i eness o
managemen could be es ima ed o he
i s ime and was es ima ed o be pa ially
e ec i e. Fi e pa hways a e no managed,
16 ha e ine ec i e managemen , one
has pa ially e ec i e managemen , six
ha e e ec i e managemen and one has
pe manen managemen .
The es ablishmen o he Bo de Managemen Au ho i y,
and h ough ha he co-o dina ion o he a -bo de
managemen o pa hways will hope ully imp o e he
e icacy o a -bo de managemen . Measu ing he
e icacy o managemen and implemen ing adap i e
managemen whe e equi ed would u he imp o e
biosecu i y.
→ no change; ↗ an inc ease; ↘ a dec ease.
73
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.8 E ec i eness
o species
ea men s
→Low ↗Fo mos (66%) o he 560 egula ed axa,
he e is no e idence ha any managemen
is aking place, and wi h he excep ion
o species unde biological con ol, he
e ec i eness o managemen is la gely
unknown.
Assessing he e ec i eness o species ea men s
a a na ional scale is based on changes in he size o
he popula ion ( o animals) o he ex en o in asion
( o plan s). These a e cu en ly no moni o ed excep
o some alien plan s ha a e he a ge o biological
con ol. The absence o a eliable baseline and egula
upda es will con inue o p e en accu a e assessmen s
o con ol e ec i eness, especially a a na ional scale.
When assessed a ine scales, he e a e examples o
pa ially e ec i e ea men s o species a some si es.
4.9 E ec i eness
o si e
ea men s
no assessed ↗The pauci y o managemen plans wi h
clea goals and egula moni o ing o
hose plans makes i di icul o assess
e ec i eness, which would ha e o be
exp essed in e ms o p og ess owa ds
achie ing he goal. Fo some si es
whe e in o ma ion is a ailable, he e a e
indica ions ha some in e en ions a e
a leas pa ially e ec i e, bu he goals
o managemen a e ypically uns a ed,
making such assessmen s di icul . The e
is no in o ma ion o sugges ha he
si ua ion has changed since he second
epo .
The e a e almos no ou inely collec ed da a o assess
he e ec i eness o si e ea men s, ei he in e ms o
changes in he ex en o he a ea in aded, o in e ms
o ecosys em eco e y ollowing con ol. Accu a e
assessmen s a e only possible o small si es ha ha e
been he subjec o esea ch s udies.
→ no change; ↗ an inc ease; ↘ a dec ease.
80
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Biological con ol aside, he mos ecen in en ional e-
lease in na u e was Salmo u a (b own ou ) in 1964
(Coope e al. 1992). None o hese in en ionally in o-
duced axa a e s ill p esen on he islands. Nowadays, no
alien axa may be in en ionally in oduced o he islands.
S ong biosecu i y measu es we e adop ed in he 2000s,
bu nume ous in oduc ions we e de ec ed despi e
hese e o s. The de ec ed o ganisms we e killed upon
de ec ion and ei he iden i ied in si u, sen o expe s
o iden i ica ion o simply disposed o . Taxa epo ed
by en i onmen al con ol o ice s (ECOs) in hei epo s
o he DFFE included cock oaches, house and ui lies,
c icke s, and a numbe o plan p opagules. The las de-
ec ion was a cock oach spo ed in 2022 a he esea ch
s a ion; a specimen was aken which is ye o be iden i-
ied (G e e pe s. comm. 2023). Gi en ha mos de ec-
ions a e no iden i ied o species le el, he cu en a e
o un egula ed in oduc ions is no known wi h ce ain-
y (e.g., o ganisms ound one yea migh be he same o
di e en species as in p e ious yea s). I is also di icul
o e alua e whe e he biosecu i y b each occu ed. Ne -
e heless, gi en he only en y poin o Ma ion Island is
he esea ch base, and ha biologis s a e s a ioned he e
yea - ound, he delay be ween in oduc ions and de ec-
ions is likely o be e y sho .
The only anspo essel ha egula ly isi s he islands is
he Sou h A ican go e nmen owned SA Agulhas II. The
SA Agulhas II isi s Ma ion Island in Ap il–May e e y yea
anspo ing people, ood and supplies o he island, and
b inging was e and people back. As he e is no dock on
he island, helicop e s a e used o anspo people and
supplies be ween he essel and he island. Occasionally,
he SA Agulhas II isi s he islands mo e han once a yea ,
and on e y a e occasions o he essels also isi (e.g.,
a documen a y c ew a elled o Ma ion Island in 2020).
Ma ion Island is inhabi ed yea - ound by app oxima ely 20 scien is s and suppo s a ; his g oup changes e e y yea
du ing he elie oyage o he SA Agulhas II. Du ing he elie oyage, o he people isi he island o app oxima ely
ou weeks o pe o m esea ch o main enance o he base and me eo ological s a ion. Howe e , no mo e han 80
people a e allowed o o e nigh on he island. No ou ism is allowed. Almos all ac i i y and esea che s a e based a he
esea ch base, al hough he e a e a numbe o esea ch hu s do ed a ound he island, which a e isi ed by esea ch s a .
Du ing he elie oyage he hu s ha e a high occupa ion a e; his is much lowe du ing he es o he yea . In o ma ion
on he numbe o isi o s pe yea o he islands has been eques ed om DFFE bu was no ecei ed by he ime his
epo was inalised.
Al hough qua an ine measu es a e adop ed a Cape Town ha bou be o e he ship can depa , his o ically a signi ican
numbe o p opagules (alien plan seeds) and li e insec s ha e been ound in, o on, con aine s and expedi ione ’s
clo hing and luggage (Lee & Chown 2009). The elease o ballas wa e o galley was e is p ohibi ed wi hin 200 nau ical
miles o he PEIs (DFFE 2010), bu his is s ill a po en ial pa hway, as is hull ouling (Lee & Chown 2007). Finally, alien
axa ha ha e been in oduced by humans o Ma ion Island could na u ally dispe se o P ince Edwa d Island by wind
o seabi ds (Ryan e al. 2003), i.e., he ‘unaided’ pa hway is po en ially ac i e.
The cu en PEIs Managemen Plan (DFFE 2010) p o ides p o ision o isi P ince Edwa d Island a mos e e y ou
yea s by a maximum o en expedi ione s o a pe iod o eigh days. P ince Edwa d Island was isi ed in 2010, bu only
again in No embe 2023. Resul s o he ecen isi could no be included in his epo .
0
20 000
40 000
60 000
80 000
Weigh (kg)
2014 2016 2018 2020
Yea
Food
Machine y
O he
Figu e 5 .2 . The olume o goods anspo ed o he PEIs
(2014–2021). The olume o ood and o he ca go ans-
po ed o he PEIs has been a iable o e ime and no
long- e m pa e n is appa en . Occasional wo k on he e-
sea ch base o upg ading o acili ies esul s in peaks in he
machine y anspo ed (c . 2018). These da a we e used o
es ima e in oduc ion pa hway p ominence o he ood
con aminan , con aine and bulk ca go, and machines and
equipmen pa hways. While bo h he ood con aminan
and machines and equipmen pa hways ha e ‘Mino ’ in o-
duc ion pa hway p ominence, he in oduc ion pa hway
p ominence o he con aine and bulk ca go pa hway is
‘Mode a e’ (Table 5.1).
81
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Table 5 .2 . Only h ee wi hin-coun y pa hways a e p esen on he P ince Edwa d Islands by which alien species a e known, o
s ongly suspec ed.
Pa hway ca ego y:
subca ego y
Wi hin-coun y
pa hway p ominence
Examples o wi hin-coun y dispe sal
T anspo -
s owaway: People/
equipmen
No known Lee and Chown (2011) ound 420 seeds ca ied on 225 di e en
clo hes i ems on expedi ione s ha we e e u ning o he
Sou h A ican mainland om Ma ion Island. These p opagules
could ha e po en ially been sp ead a ound he island (a leas
h ee seeds we e o in asi e plan species). The p ominence o
he pa hway on he island has no , howe e , been speci ically
moni o ed.
T anspo -
s owaway:
Con aine and bulk
ca go
Mino Sagina p ocumbens was possibly sp ead ac oss he island
du ing hu es ocking, when con aine s a e d opped a hu s by
helicop e . This happens once a yea . O he plan s could ha e
been sp ead by his means oo. The in asi e slug De oce as
pano mi anum has been sp ead a ound Ma ion Island h ough
wooden c a es ha a e packed a ound he esea ch s a ion p io
o ai c a and ship ope a ions (Chown e al. 2002).
Unaided Mode a e Se e al plan species ha e sp ead o e ai ly la ge dis ances on
P ince Edwa d Island du ing a ime when no humans isi ed he
island. I can be expec ed ha mos inc eases in he ange o
in asi e species on Ma ion Island a e simila ly unaided.
5.1.2. Wi hin-island pa hways
Ou o 44 pa hways, only h ee a e p esen wi hin he islands (Table 5.2). On he PEIs, wind and seabi ds likely c ea e
oppo uni ies o he dispe sal o in asi e plan s (Ryan e al. 2003). These a e classi ied he e as mode a e pa hways on
bo h islands as s ong winds a e equen and he e a e many seabi ds ( hough Ma ion Island has seen some dec eases
in seabi d popula ions as a esul o ca s and mice). Some species may sp ead wi h people and hei luggage as hey
a el a ound he island, bu he ex en o which people mo e a ound he island is no known. The s owaway ou e ( ia
helicop e s) is likely less p ominen due o he low equency o hese ypes o mo emen s ( his pa hway is usually p es-
en o h ee o ou weeks a yea , while humans a e p esen a all imes), and also less p ominen now han p e iously
as s ic e biosecu i y egula ions ha e been in oduced (DFFE 2010). The con idence o his anking is low.
On P ince Edwa d Island he dispe sal o in asi e plan s [e.g., Sagina p ocumbens (bi deye pea lwo ) and Poa annua
(annual meadow g ass)] has likely occu ed ia wind and wi h seabi ds (Ryan e al. 2003). E idence om P ince Edwa d
Island, whe e humans a e absen o yea s a a ime and whe e he sp ead o alien species is apid (Le Roux e al. 2013),
sugges s ha he unaided pa hway is impo an o alien plan s on he islands; his is likely a common pa hway o
dispe sal o alien species. On Ma ion Island, i is hough ha S. p ocumbens was sp ead om he esea ch base by heli-
cop e du ing annual es ocking o he hu s (G emmen & Smi h 1999). The cons uc ion o a s eel helicop e pad a he
new esea ch base has likely educed dispe sal h ough his pa hway, al hough he helicop e s ill lands on ege a ion
a he hu s and so migh be esponsible o sp eading p opagules. I is likely ha some p opagules a e sp ead by ield
wo ke s; his has no been in es iga ed.
82
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
5.2 Species
5.2.1. Numbe and s a us o alien species
Nine y-one (91) alien axa ha e been eco ded a some
poin on he PEIs; wo axa a e eco ded as c yp ogen-
ic (i.e., na i i y has no been con i med)1; and one plan ,
Oche ophila ine is ( loa ing-hea ) is hough o ha e
a i ed unaided ia ag an bi ds om Sou h Ame ica
since humans i s a i ed on he island (Kalwij e al. 2019)
and so is conside ed na i e (Appendix 7). Two spide spe-
cies (genus My o) we e ci ed as alien in he 1980s (Wa -
kins & Coope 1986) bu we e la e co ec ed o be na i e
(Chown & F oneman 2008). Ou o he 91 alien axa e e
eco ded, 44 a e s ill p esen , he p esence o six axa is
doub ul un il e adica ion is con i med and he emaining
41 a e no longe p esen . The e a e cu en ly no alien axa in cap i i y o unde cul i a ion. O he 44 alien axa cu en ly
p esen , 26 a e in asi e, 13 a e na u alised bu no in asi e, and i e canno be assigned o one o he basic in oduc ion
s a us ca ego ies (i.e., i is unclea i hey a e na u alised, in asi e o nei he ) (Figu e 5.3). The e o e, mo e han hal o he
alien axa p esen on he PEIs a e in asi e. O he 26 in asi e axa, 17 a e in e eb a es, se en a e plan s, one is a ungus and
one is a mammal (Figu e 5.4); he e a e no alien bi ds, ep iles o amphibians (see Supplemen a y Ma e ial S5.2). All alien
axa a e ei he e es ial o eshwa e species, as, despi e an ac i e sea ch, no ma ine alien species ha e been de ec ed o
da e (G e e e al. 2020).
5.2.2. Ex en o alien species
The mos widesp ead species on bo h islands a e Sagina p ocumbens (p esen in 166 hal -minu e g id cells, hmgcs2), P.
annua (204 hmgcs), and Ce as ium on anum (common mouse-ea chickweed; 162 hmgcs) (DFFE 2010; Le Roux e al.
2013; Mai al e al. 2022). The in asi e sp ing ail Pogonogna hellus la escens has inc eased i s dis ibu ion o highe al-
i udes due o ising empe a u es associa ed wi h clima e change (Kgopong 2019). Fo u he de ails see Appendix 7.
The ECOs on Ma ion Island ha e s a ed o map he ex en o in asions and o c ea e polygon maps o assess p og ess
on plan con ol measu es. DFFE p o ided da a o h ee species: Ag os is gigan ea (black ben g ass, 1.39ha); Rumex
ace osella (sheep so el, 0.1ha); and Luzula mul i lo a (wood ush, 1.2ha) (see maps in Supplemen a y Ma e ial S5.3).
5.2.3. Abundance o alien species
Plan co e has been assessed du ing 2018–2020 along a ious ansec s on Ma ion Island (G e e & Le Roux, unpublished
da a). Na i e plan s we e ound o ha e he highes pe cen age co e (54.6%), ollowed by ba e g ound/ ocks (42.8%),
and las ly alien plan co e (2.6%). O he alien plan s, S. p ocumbens had he highes abundance (mean co e = 0.9%),
ollowed by P. annua (0.39%), Ag os is s oloni e a (c eeping ben g ass; 0.1%), C. on anum (0.07%), and P. p a ensis (0.04%).
The abundance o in asi e (and c yp ogenic) in e eb a es has been assessed o di e en axonomic g oups [e.g.,
sp ing ails (Collembola) and mi es (Aca i)], in e ms o indi iduals pe squa e me e in di e en ege a ion ypes o
habi a s (Ba endse e al. 2002; Hugo e al. 2006; T easu e e al. 2019; Chown e al. 2022). In some s udies, mo e de ail
is p o ided (e.g., li e s age, sex; Khoza e al. 2005), bu he e ha e been no es ima es o o al popula ion sizes o any
1An uniden i ied mi e species om he amily Cillibidae was i s eco ded om Ma ion Island du ing 1996 o 1997 (Ma shall e al. 1999). This amily
had no p e iously been eco ded in he sub-An a c ic and his species was conside ed ‘likely’ an in oduced species (Ma shall e al. 1999). Howe e ,
since his ini ial collec ion no p og ess has been made in de e mining he iden i y o s a us o he species, despi e i equen ly being he nume ically
dominan mi e species in some habi a s (see e.g., Ba endse e al. 2002).
2hmgcs a e ~0.59km2, oughly 926m by 635m.
In asi e
Na u alised
P esen (no
na u alised)
Absen
0 10 20 30 40 50
A1
B1
B2
B3
C0
C1
C2
C3
D1
D2
E
Numbe o species
Figu e 5 .3 . The s a us o alien axa in oduced o he P ince Ed-
wa d Islands (PEIs) as pe he Uni ied F amewo k o Biologi-
cal In asions (Blackbu n e al. 2011). Species ha we e p es-
en bu a e no longe (A1) a e included. See Supplemen a y
Ma e ial S5.2 o a b eak-down in o unc ional g oups. The
in oduc ion s a us o i e axa is no known and hese a e
no shown on his igu e.
83
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Figu e 5 .4 . Di e en landscapes and axa on Ma ion Island: A, black la a ell ield and Lep inella plumosa–Poa annua coas al he b-
ield landscape; B, mi e-slope habi a wi h in e mi en black la a ou c ops, sco ia hill in he backg ound; C, in asi e De oce as
pano mi anum (Eu opean slug); D, in asi e Saginap ocumbens (bi deye pea lwo ) in ligh g een apidly in ading a habi a ha
was p e iously domina ed by he na i e cushion Azo ella selago; E, in asi e Mus musculus (house mouse) damaging a na i e
A. selago cushion; and F, na i e Endange ed alba oss a isk due o p eda ion by M. musculus. Pho og aphs: A, B, C, E, © Elsa an
Ginkel; D, © Michelle G e e; F, © An on Wol aa d .
A
C
E
B
D
F
84
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
in e eb a es on he PEIs. Fo bo h islands, he in asi e (and c yp ogenic) abundance o in e eb a es a ied s ongly
be ween habi a ypes and, o Ma ion Island, wi h al i ude (Figu e 5.5, Supplemen a y Ma e ial S5.4). Fo Ma ion Island,
in asi e sp ing ails we e mo e abundan in mi es cha ac e ised by Sanionia uncina a (40380indi iduals/m2), and mi es
we e mo e abundan in he sal -sp ay ege a ion domina ed by he na i e Co ula plumosa (2623indi iduals/m2) (Fig-
u e 5.5). Simila ly, on P ince Edwa d Island he sal -sp ay ege a ion ype o C. plumosa was he mos common habi a
o mi es (15039indi iduals/m2), al hough o sp ing ails he highes abundance was ound on slopes co e ed by he
na i e Blechnum penna-ma ina (234indi iduals/m2).
The highes densi y o mice on he island was 231.8mice/ha be ween 2008–2011, wi h a o al es ima ed popula ion
size o 1760740 (McClelland e al. 2018). Annual peak densi y o mice inc eased by 430% in he hi y yea s be ween
1979–1980 and 2008–2011 (McClelland e al. 2018).
5.2.4. Impac o alien species
The impac s o indi idual in asi e axa ha e been quan i ied in a ew cases o Ma ion Island: e.g., o he now e ad-
ica ed F. ca us (Van Rensbu g & Bes e 1988; Hun e 1990), o M. musculus (C a o d 1990; Jones e al. 2019) and o
Figu e 5 .5 . Abundance o : A, in asi e sp ing ails on P ince Edwa d Island; B, in asi e sp ing ails on Ma ion Island; C, c yp ogenic (i.e.,
unce ain o igin) mi es on P ince Edwa d Island; D, c yp ogenic mi es on Ma ion Island, in e ms o indi iduals pe squa e me e.
Labels on he x-axis indica e ege a ion ype and, whe e app op ia e, he plan species o he al i ude sampled wi hin he eg-
e a ion ype – Bio ic: Poa = Bio ic g assland and he b ield (Poa cookii); Azo ella = Azo ella selago; Sal -sp ay = Coas al sal -sp ay;
Co ula = Co ula plumosa; C assula = C assula moscha a; Acaena = Acaena magellanica; Blechnum = Blechnum penna-ma ina;
Blepha = Blepha idophyllum densi olium; high-al = high-al i ude; James = Jamesoniella colo a a; mid-al = mid-al i ude; Sanionia
= Sanionia uncina a. No e ha he y-axis limi s di e be ween panels.
P ince Edwa d Island
0
50
100
150
200
250
300
350
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: soil
Mi e
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Vege a ion ype
In asi e sp ing ail densi y
�ind�m��
P ince Edwa d Island
0
5 000
10 000
15 000
20 000
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: soil
Mi e
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Alien and c yp ogenic mi e densi y
�ind�m��
Vege a ion ype
Ma ion Island
0
500
1 000
1 500
2 000
2 500
3 000
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: epili hic
Mi e: Blepha
Mi e: high−al
Mi e: James
Mi e: mid−al
Mi e: Sanionia
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Alien and c yp ogenic mi e densi y
�ind�m��
Vege a ion ype
A
Ma ion Island
0
1 0000
20 000
30 000
40 000
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: �pili hic
Mi e: Blepha
Mi e: high
Mi e: Jameson
Mi e: Sanionia
Pola dese
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Bio ic: Poa
In asi e sp ing ail densi y
�ind�m��
Vege a ion ype
B
C D
85
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
he g ass A. s oloni e a (G emmen 1997; G emmen e al. 1998). O he 20 axa s ill p esen on he PEIs o which an
en i onmen al impac has been eco ded on he PEIs, he impac magni ude, as pe he EICAT scheme, is shown in
Table 5.3.
The g ea es eco ded impac s (i.e., ‘Massi e’) a e associa ed wi h he house mouse. The house mouse is o una ely
only p esen on Ma ion Island, bu i has had impac s a he ecosys em- (C a o d 1990) and species-le els, a ec ing
he island’s only sho ebi d (Huyse e al. 2000), seabi ds (Jones e al. 2019; Jones & Ryan 2010; Dilley e al. 2017), na i e
ege a ion (Phi i e al. 2009), and in e eb a es (Van Aa de e al. 2004). The house mouse has had nega i e impac s on
plan species su i al (Azo ella selago; Phi i e al. 2009) and ep oduc ion (Uncinia compac a; Chown & Smi h 1993), in-
e eb a e abundance, biomass and body size (Chown & Smi h 1993; C a o d & Schol z 1987; T easu e & Chown 2014;
McClelland e al. 2018), and alba oss chick su i al (Jones & Ryan 2010; Dilley e al. 2017). House mouse bu owing
also al e s sedimen mo emen a es (E iksson & Eld idge 2014) and likely impac s on nu ien cycling (C a o d 1990;
Smi h & S eenkamp 1990). E idence shows ha he e has been a shi in mouse beha iou wi h p eda ion on seabi ds’
chicks inc easing o e ime and ecen eco ds o mice a acking adul seabi ds (Jones e al. 2019). The ecen inc ease
in mouse impac s on seabi ds u he emphasises he impo ance o achie ing e adica ion soon.
Th ee in asi e plan species, including he g ass A. s oloni e a, ha e had ‘Majo ’ impac s on na i e ege a ion and soil
auna communi ies (G emmen 1997; G emmen e al. 1998). Ve y li le has been documen ed on he impac s o e es-
ial in e eb a es. Las ly, he ungal ascomyce e Bo yo inia uckeliana was ound o signi ican ly a ec he dis ibu ion
and abundance o a na i e plan species (Kloppe s & Smi h 1998).
5.3 Si es
5.3.1. Alien species ichness
Alien plan species ichness is highes close o he Ma ion Island base and me eo ological s a ion, and high along
he no he n and eas e n coas al a eas, pa icula ly in a eas wi h cu en o his o ic an h opogenic dis u bances (e.g.,
esea ch ield hu s; Le Roux e al. 2013). The highes alien plan ichness a he hmgc-scale was eigh species (a he
esea ch s a ion). Alien plan ichness on P ince Edwa d Island is mo e e enly sp ead ac oss he island, wi h he highes
ichness along he coas and he s eep esca pmen on he no hwes e n side o he island [maximum alien plan spe-
cies ichness a he hmgc-scale was h ee species; Le Roux e al. (2013)].
5.3.2. Rela i e in asi e abundance
Es ima es om a 2008 s udy sugges ed ha less han 5% o he PEIs had been co e ed by alien plan s (G emmen &
Smi h 2008). In a mo e ecen s udy, Le Roux e al. (2013) de e mined ha alien plan species we e p esen in 42% o
Ma ion Island’s hmgcs and in 53% o P ince Edwa d Island’s hmgcs. The mean co e o all in asi e plan species is 2.6%
Table 5 .3 . The numbe o alien axa wi h di e en le els o eco ded en i onmen al impac on he P ince Edwa d Islands (PEIs). Taxa
we e assigned o a ious ca ego ies o impac based only on s udies om he PEIs (G e e e al. 2017). See Supplemen a y Ma e ial
S5.2 o he app oach aken. This able only includes he 44 axa cu en ly p esen and so does no include ca s (which had caused
‘Majo ’ impac s).
Taxon En i onmen al Impac (~EICAT)
Da a De icien Minimal Mino Mode a e Majo Massi e
Mammals 0 0 0 0 0 1
Mic obial species 0 0 0 1 0 0
Te es ial and eshwa e plan s 6 4 2 3 3 0
Te es ial in e eb a es 24 0 5 1 0 0
86
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
on Ma ion Island (G e e unpublished da a). This es ima e is based on 501 plo s o 3x3m ha a e sp ead ac oss he
island, hough la gely excluding he pola dese in e io whe e no ascula plan s occu . Gi en ha hese plo s co e
only a small pe cen age o he island, con idence in his es ima e is low. The e is spa ial a ia ion in ela i e in asi e
abundance ac oss Ma ion Island. Coas al habi a s a e gene ally mo e in aded han inland habi a s. No da a a e a ail-
able on he ela i e abundance o alien plan s o P ince Edwa d Island.
Fo bo h islands, he ela i e in asi e abundance o in e eb a es a ied s ongly be ween habi a ypes and, o
Ma ion Island, along he al i udinal g adien (Figu e 5.6). Sp ing ails a e ela i ely well su eyed and ha e a ela i e
in asi e abundance ha a ies be ween 0 and 2% on P ince Edwa d Island and be ween 0 and 90% on Ma ion Island
(mean ela i e abundance = 28%; T easu e e al. 2019; Chown e al. 2022). The ela i e in asi e abundance o sp ing-
ails is highes a lowe al i udes and in b yophy e- and e n-domina ed ege a ion ypes. Spide s ha e only been ade-
qua ely sampled on Ma ion Island (and only om i e loca ions on he eas e n side o he island) o documen ela i e
in asi e abundance, and da a show ela i e in asi e abundance a ying om 0–98% (mean = 37%; Khoza e al.
2005). The ela i e abundance o alien spide s was lowes a he wo si es wi h he highes ele a ion. Alien mi es com-
p ise 0–26% o all mi es on P ince Edwa d Island (mean = 8%; Hugo e al. 2006) and 3–28 % o mi es on Ma ion Island
(mean = 14%; Ba endse e al. 2002). Howe e , due o unce ain y ega ding he iden i y (and s a us) o a mi e axon in
he Cillibidae, which comp ises 95–100% o he alien mi e indi iduals sampled om he islands, he e is conside able
unce ain y in hese es ima es. Rela i e in asi e abundance o Isopoda is 100% due o he absence o na i e isopods.
Figu e 5 .6 . Rela i e abundance o : A, in asi e sp ing ails on P ince Edwa d Island; B, in asi e sp ing ails on Ma ion Island; C, alien
and c yp ogenic (i.e., unce ain o igin) mi es on P ince Edwa d Island; D, alien and c yp ogenic mi es on Ma ion Island. Labels
on he x-axis indica e ege a ion ype and, whe e app op ia e, he plan species o he al i ude sampled wi hin he ege a ion
ype – Bio ic: Poa = Bio ic g assland and he b ield (Poa cookii); Azo ella = Azo ella selago; Sal -sp ay = Coas al sal -sp ay; Co ula
= Co ula plumosa; C assula = C assula moscha a; Acaena = Acaena magellanica; Blechnum = Blechnum penna-ma ina; Blepha =
Blepha idophyllum densi olium; high-al = high-al i ude; James = Jamesoniella colo a a; mid-al = mid-al i ude; Sanionia = Sanio-
nia uncina a. No e ha he y-axis limi s di e be ween panels.
P ince Edwa d Island
0
1
2
3
4
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: soil
Mi e
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Rela i e in asi e sp ing ail
abundance (%)
Vege a ion ype
0
10
20
30
40
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: soil
Mi e
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Rela i e alien and c yp ogenic mi e
abundance (%)
P ince Edwa d Island
Vege a ion ype
0
10
20
30
40
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: epili hic
Mi e: Blepha
Mi e: high−al
Mi e: James
Mi e: mid−al
Mi e: Sanionia
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Ma ion Island
Rela i e alien and c yp ogenic mi e
abundance (%)
Vege a ion ype
A
Ma ion Island
0
20
40
60
80
100
Bio ic: Poa
Fell�eld: Azo ella
Fell�eld: �pili hic
Mi e: Blepha
Mi e: high
Mi e: Jameson
Mi e: Sanionia
Pola dese
Sal −sp ay: Co ula
Sal −sp ay: C assula
Slope: Acaena
Slope: Blechnum
Bio ic: Poa
Vege a ion ype
Rela i e in asi e sp ing ail
abundance (%)
B
C D
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Sagina p ocumbens (© Nicolas Weghaup ).
87
Rela i e abundance da a o some axa (e.g., Insec a) a e no a ailable due o he lack o comple e su eys (i.e., no all
species wi hin he axon eco ded du ing sampling).
5.3.3. Impac o in asions
G emmen (1997) es ima ed ha in asion by g asses (plo s domina ed by A. s oloni e a bu wi h p esence o o he
aliens) led o a 50% dec ease in na i e ege a ion ichness in in aded d ainage lines. B yophy e biomass was also 16
imes lowe in hese habi a s, bu he species ichness o mac oin e eb a es and mi es was highe in in aded a eas
(G emmen e al. 1998). Gab iel e al. (2001) did no ind a nega i e impac o in asi e sp ing ails on ei he he ichness
o abundance o na i e sp ing ails ac oss 13 habi a s on Ma ion Island. Howe e , a compa ison o Ma ion and P ince
Edwa d islands wi h he unin aded Hea d Island sugges ed ha in asi e sp ing ails caused a leas a ou - old decline
in he densi y o h ee na i e sp ing ail species (Chown e al. 2022).
5.4 In e en ions
5.4.1. Inpu – quali y o egula o y amewo k
The PEIs ha e he highes le el o p o ec ion a o ded o any na u al a ea unde Sou h A ican law. The islands we e
decla ed a Special Na u e Rese e in 1995 and a e ese ed p ima ily o scien i ic esea ch and en i onmen al moni o -
ing (DFFE 2010). Rec ea ion ac i i ies a e p ohibi ed. The PEIs we e designa ed a Ramsa We land Si e o In e na ional
Impo ance in 2007, and in 2013, he P ince Edwa d Island Ma ine P o ec ed A ea was o mally decla ed (DFFE 2010).
Alien species a e no allowed o be in oduced o he PEIs.
The NEM:BA A&IS Lis s o 2020 include 13 o he 50 axa cu en ly p esen (o doub ul) on he islands. Howe e , wo
axa which a e being managed a e no cu en ly lis ed and ou axa which a e lis ed (and he e o e should be man-
aged) a e no being managed (Table 5.4). None o he in asi e species cu en ly lis ed o he PEIs a e lis ed on he
mainland. No isk analyses ha e been pe o med o axa lis ed on he PEIs (Table S4.4). Gi en ha ideally he PEIs
should be alien- ee an e alua ion o managemen op ions conduc ed and egula ly upda ed wi hin he scope o he
PEIs Managemen Plan would likely p o ide he necessa y and su icien in o ma ion o guide in e en ions a he han
conduc ing isk analyses solely o he PEIs.
88
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Scien i ic
name
Ve nacula
name
Regula o y
lis ing
In oduc ion
s a us
T ea ed o
moni o ed
No es on con ol implemen ed
Ag os is
cas ellana
ben g ass 1a PEI
1b MI
P esen bu no
na u alised
Yes In lo escences a e cu and bagged and he emaining pa s o he plan s sp ayed
wi h he bicide (Debbie Mui pe s. comm. 22 May 2023). Howe e , he o m o
A. cas ellana occu ing on MI is e y di icul o dis inguish om A. s oloni e a,
and u he e o s a e equi ed o cla i y he dis ibu ion o his species, likely
supplemen ed wi h DNA ba coding as a means o alida e iden i ica ion based on
mo phology.
Ag os is
gigan ea
black ben
g ass
1a Na u alised bu
no in asi e
Yes Mechanical emo al o abo eg ound biomass and he bicide applica ion
(Glyphosa e; 2.5% Kilo Max).
Ag os is
s oloni e a
c eeping
ben g ass
1a PEI
1b MI
In asi e No None implemen ed (success ul e adica ion deemed un easible; G e e e al. 2017).
Alopecu us
genicula us
ma sh
ox ail
1a Doub ul
(e adica ion o
be con i med)
Yes Manual emo al was conduc ed; assumed o be no longe p esen since 2012
(G e e e al. 2017).
Ce as ium
on anum
common
mouse-ea
chickweed
1b In asi e No None implemen ed because i is widesp ead (G e e e al. 2017; DEA & DST-NRF CIB
2021).
Elymus
epens1
couch g ass 1a Na u alised no
in asi e
Yes Mechanical emo al o abo eg ound biomass and he bicide applica ion
(Glyphosa e; 2.5% Kilo Max 700g/kg.)
Fes uca ub a c eeping
ed escue
1a Na u alised no
in asi e
Yes He bicide applica ion (Glyphosa e; 2.5 Kilo Max).
Holcus
lana us
common
el e g ass
No lis ed Doub ul
(e adica ion o
be con i med)
Yes The species was manually emo ed in 2012, si e and su ounding a eas ha e been
moni o ed mon hly since emo al o de ec any eg ow h o new plan s.
1Lis ed as Ely igia epens (L.) Des . ex Ne ski (= Ag opy on epens (L.) P. Beau ., Elymus epens (L.) Gould) unde he A&IS Lis s o 2020.
Table 5 .4 . Alien axa lis ed unde he NEM:BA A&IS Regula ions o 2020 o he P ince Edwa d Islands (PEIs) o o which an e adica ion plan has been de eloped [c . Appendix 7; Wilson
(2023)]. Only lis ings ele an o he PEIs a e included he e. In o ma ion on he implemen ed con ol measu e was ob ained mainly om he Depa men o En i onmen al A ai s (DEA)
and DST-NRF CIB 2012–2013, las upda ed in 2021, pe sonal communica ion wi h DFFE Specialis P og amme Manage Debbie Mui , o indica ed o he wise. Technically, as he PEIs a e
o -sho e islands, he ollowing a e also lis ed as 1b [Alec o is chuka (Chuka pa idge), O yc olagus cuniculus ( he Eu opean abbi ), Ra us no egicus, R. a us, and R. anezumi ( he No -
wegian, b own and Asian house a espec i ely)], and he ollowing as 1a [Cap a hi cus (goa ) and Felis ca us (domes ic ca )], bu none o hese a e cu en ly p esen on he island. PEI is
he P ince Edwa d Island and MI is Ma ion Island.
89
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Scien i ic
name
Ve nacula
name
Regula o y
lis ing
In oduc ion
s a us
T ea ed o
moni o ed
No es on con ol implemen ed
Juncus
e usus
common
ush
No lis ed Doub ul
(e adica ion o
be con i med)
Yes Po en ially e adica ed, cu en ly being moni o ed o con i m e adica ion.
Luzula
mul i lo a
wood ush 1a Na u alised no
in asi e
Yes He bicide applica ion (Glyphosa e; 2.5% Kilo Max). A gene ic s udy has been
ecommended o con i m ha i di e s om he na i e suban a c ic Luzula species
(and so unequi ocally alien).
Mus
musculus
house
mouse
1a MI In asi e Yes Bai ed aps a e deployed bo h ou side and inside he base and hu s o p o ec
ood and human heal h (Wol aa d pe s. comm. 2022). Mice a e no o he wise
subjec o con ol, al hough an e adica ion a emp is being planned h ough he
‘Mouse- ee Ma ion P ojec ’, due o s a in 2025 i enough unds a e aised.
Poa p a ensis Ken ucky
blueg ass
1a PEI
1b MI
In asi e No None implemen ed (G e e e al. 2017; DEA & DST-NRF CIB 2021).
Po cellio
scabe
common
ough
woodlouse
No lis ed Doub ul
(e adica ion o
be con i med)
Yes The woodlouse is belie ed o ha e been success ully e adica ed in 2012, bu his
needs o be moni o ed o con i ma ion. Con ol is ecommended ia applica ion o
py e h oid (Supe C ackdown).
Rumex
ace osella
sheep so el 1a Na u alised no
in asi e
Yes Mechanical emo al o abo eg ound biomass (in lo escence is cu and hen plan
pulled) (Debbie Mui pe s. comm. 22 May 2023).
Sagina
p ocumbens
bi deye
pea lwo
1b In asi e No None implemen ed (success ul e adica ion deemed un easible by G e e e al.
2017), bu he po en ial o classical biocon ol is unde in es iga ion.
S ella ia
media
common
chickweed
1a PEI
1b MI
Doub ul Yes I used o be sp ayed wi h he bicide (2.5% Kilo Max). I has no been seen by he
ECOs la ely, cu en ly being moni o ed.
Table 5 .4 . (Con inued) Alien axa lis ed unde he NEM:BA A&IS Regula ions o 2020 o he P ince Edwa d Islands (PEIs) o o which an e adica ion plan has been de eloped [c . Appendix 7;
Wilson (2023)]. Only lis ings ele an o he PEIs a e included he e. In o ma ion on he implemen ed con ol measu e was ob ained mainly om he Depa men o En i onmen al A ai s
(DEA) and DST-NRF CIB 2012–2013, las upda ed in 2021, pe sonal communica ion wi h DFFE Specialis P og amme Manage Debbie Mui , o indica ed o he wise. Technically, as he PEIs
a e o -sho e islands, he ollowing a e also lis ed as 1b [Alec o is chuka (Chuka pa idge), O yc olagus cuniculus ( he Eu opean abbi ), Ra us no egicus, R. a us, and R. anezumi ( he
No wegian, b own, and Asian house a espec i ely)], and he ollowing as 1a [Cap a hi cus (goa ) and Felis ca us (domes ic ca )], bu none o hese a e cu en ly p esen on he island.
PEI is he P ince Edwa d Island and MI is Ma ion Island.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
3.2 Rela i e
in asi e
abundance
↗low ↘Mean plan co e on Ma ion Island (MI)
2.6%; no plan da a o his indica o on PEI.
In e eb a es’ ela i e in asi e abundance
a ies be ween 0–2% o PEI sp ing ails o
28% on MI; o mi es be ween 8% a PEI
and 14% a MI; howe e , he unce ain y
o na i i y s a us o Cillibidae make his
es ima e e y low con idence. Spide s ha e
been s udied only on MI (37% mean ela i e
abundance) and he e a e no da a o insec s
due o a lack o comple e su eys.
Expec ed o inc ease as species sp ead ac oss he
islands, and also as clima e amelio a ion may make
he en i onmen mo e a ou able o gene alis
in ade s.
3.3 Impac o
in asions
↗low ↘Because abundance is inc easing, and
because he e a e some indica ions ha
he amelio a ion o clima e on he PEIs is
bene i ing in asi e o e na i e species, he
impac is assumed o inc ease. [e.g., mice
ha e inc eased popula ions, McClelland e
al. (2018)].
Expec ed o inc ease as species sp ead ac oss
he islands, inc easing island-wide impac s; bu
also expec ed o inc ease as clima e amelio a ion
may make he en i onmen mo e a ou able o
gene alis in ade s.
4. Le el o
success in
managing
in asions
→high ↗Some managemen ac ions ha e been
success ul and species a e being moni o ed
o con i m e adica ion. The dis ibu ion o
some o he axa has emained s able (in
some cases, due o axa being con olled).
Howe e , a ew axa ha e inc eased in
ex en . So o e all he e is no change and he
le el o success is pa ial.
Assessmen done in 2023 based on da a
om 2020–2022 we e compa ed o p e ious
assessmen o indica e changes and
achie emen s o managing in asions.
I success ul, he ‘Mouse- ee Ma ion’ P ojec would
be a signi ican achie emen , and al hough less
p essing, o he e adica ions would also lead o an
inc ease in his indica o .
→ no change; ↗ an inc ease; ↘ a dec ease.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.1 Quali y o
egula o y
amewo k
↗high ↗The cu en managemen plan was
de eloped in 2010. The e adica ion plan is
e ised and upda ed e e y yea . The quali y
o egula o y amewo k is conside ed
pa ial.
Regula ions a e in he p ocess o being e ised and
a new Managemen Plan is mean o go ou o
public commen in 2023. The p ocess o p io i ising
managemen a ge s will likely be mo e e ec i e
i decoupled om na ional-le el egula ions and
p ocesses.
4.2 Money spen ↗medium ↗The DFFE budge o he bicides and
equipmen o he con ol o alien species
on he PEIs du ing 2011–2022 was
ZAR58664. This is an unde es ima e, as a
ull alue was no p o ided. Fo example, he
cos o hou s in es ed by ECOs on con ol o
alien species has no been es ima ed.
A educ ion in o al cos s o in asi e clea ing
is expec ed in line wi h he in asi e species
managemen plan i e adica ion o cu en ly
doub ul species is con i med. Signi ican unds will
be spen in a sho pe iod o ime i he ‘Mouse F ee
Ma ion’ P ojec is implemen ed.
4.3 Planning
co e age
↗high ↗All se en ac i e human-media ed
pa hways ha e managemen plans in
place. The in asi e species managemen
plan is complian wi h he NEM:BA A&IS
Regula ions Sec ion 76 (A), Sec ion 70 (1)(2)
(3). The managemen plan co e s Ma ion
and P ince Edwa d Island, so all si es ha e
a managemen plan in place, al hough
ou da ed.
E adica ion plan o be upda ed a e second pa y
assessmen (Ap il/May 2023) o include his o ical
and ac i e species si es. A mapping sys em ha
can e lec his o ical and ac i e con ol me hods
will be a ailable. Mapping sys em can be used
o es ima ing changes in in asions, allowing o
adap i e managemen and upda e o e adica ion
plans.
4.4 Pa hways
ea ed
→high ↗All pa hways by which alien species can
be in oduced equi e managemen , and
hey a e all being managed unde s ic
biosecu i y measu es.
In o ma ion on biosecu i y b eaches (e.g.,
iden i ica ions) can be used o imp o e p o ocols.
*→ no change; ↗ an inc ease; ↘ a dec ease.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.5 Species
ea ed
→high ↗O he 13 lis ed alien axa (12 plan species
and one mammal), 8 plan s a e subjec ed
o some o m o managemen (ei he
in lo escences cu and bagged, plan s
pulled, o he bicide). Fi e po en ially
e adica ed species a e being moni o ed o
con i m s a us ( ou plan species and he
isopod). Mice a e only con olled a he
base and hu s. In asi e plan s’ his o ical
si es and ac i e si es a e being mapped and
moni o ed.
Con i ma ion o e adica ion o i e species will
only be done i hey ha e no been seen o ou
consecu i e second pa y assessmen s (12 yea s). I
he ‘Mouse F ee Ma ion’ e adica ion plan goes ahead
in 2025 a con ingency plan a e mass bai ing mus
be implemen ed.
4.6 Si es ea ed →high ↗Ma ion Island is ea ed on a egula basis;
howe e , P ince Edwa d Island can only be
isi ed e e y ou yea s (bu has no been
isi ed in he las en yea s), he e o e he e
is no managemen cu en ly applied on ha
si e.
Mapping and moni o ing plan will indica e his o ical,
as well as ac i e si es o indica e e ec i eness o
con ol plans.
4.7 E ec i eness
o pa hway
ea men s
no assessed ↗The necessa y quan i a i e da a o assess
his indica o a e no a ailable.
In o ma ion on biosecu i y b eaches (e.g.,
iden i ica ions) can be used o imp o e p o ocols.
4.8 E ec i eness
o species
ea men s
↗high ↗Many in asi e species a e subjec o
some o m o con ol and ou comes a e
moni o ed. The e a e 11 axa ha a e
e adica ion a ge s, wi h i e ha a e
po en ially e adica ed and ha ha e
become moni o ing a ge s, as hey ha e
no been seen o se e al consecu i e yea s.
DFFE h ee-yea assessmen esul s indica e
a educ ion in ac i e si es. Fou widesp ead
in asi e plan species a e conside ed
inapp op ia e a ge s o e adica ion and
he e o e a e no being ea ed.
Mapping and moni o ing p og amme will indica e
e ec i eness o con ol p og ammes in u u e.
New con ol echnologies will likely be needed i
cu en widesp ead in asi e axa, o he han he
house mouse, a e o be e ec i ely con olled.
→ no change; ↗ an inc ease; ↘ a dec ease.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Indica o T end Con idence Desi ed
end
Cu en s a us and end Ou look
4.9 E ec i eness
o si e
ea men s
↗high ↗Second pa y assessmen implemen ed
h ee-yea ly a Ma ion Island o quan i y
e ec i eness o ea men s and possible
educ ions o alien species popula ions
(plan s, isopod and mice).
Moni o ing plan da a will be used o amend and
upda e he in asi e species managemen plan.
→ no change; ↗ an inc ease; ↘ a dec ease.
Juncus e usus (© Josep Ges i).
100
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
Aga e sisalana (© Fo es and Kim S a ).
100
101
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
CHAPTER
6
GAPS
Au ho s: John R. Wilson, Ka elyn T.
Faulkne , Lau a Fe nández Winze ,
Emily J. McCulloch-Jones, B ian W.
an Wilgen & Tsungai A. Zengeya
Chap e s uc u e and gaps1
• This chap e e alua ed gaps using ou app oaches: 1) p og-
ess in colla ing in o ma ion needed o he indica o s used in
his epo was e alua ed and gaps in his p ocess no ed (Sec-
ion 6.1 and Table 6.1); 2) gaps iden i ied in he second epo
(including gaps in in o ma ion, managemen and go e nance)
we e e-e alua ed (Sec ions 6.2–6.7); 3) he key indings and
implica ions highligh ed in he book on biological in asions
(Van Wilgen e al. 2020) we e e alua ed (Sec ion 6.8 and Table
6.2); and 4) gaps in he scope o his epo iden i ied du ing
he e iew o he epo we e summa ised (Sec ion 6.9). The
chap e concludes wi h Sec ion 6.10: he way o wa d. Key
gaps a e highligh ed below.
• Tes ing he indica o s de eloped o his epo and aligning
hem o o he go e nmen epo ing p ocesses could im-
p o e he low o in o ma ion om obse a ions o policy and
managemen .
• The e is insu icien in o ma ion on how in asi e species mo e
and a e mo ed a ound Sou h A ica o de elop s a egies o
e ec i ely manage he sp ead o in asions.
• The planning o in e en ions would be acili a ed i da a on
he p esence, dis ibu ion and abundance o alien species
we e sys ema ically collec ed, colla ed and in eg a ed in o na-
ional and global da abases.
• The sys ema ic quan i ica ion o he impac s o biological in a-
sions is needed o acili a e he p io i isa ion o in e en ions,
1All bu he las wo key gaps a e he same as he second epo albei wi h some
mino eph asing. While he e has been p og ess add essing some o hese gaps,
none a e ully add essed ye (see Tables S6.1, S6.2).
Hippos su ounded by wa e hyacin h (© Ka elyn Faulkne ).
102
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
p o ide a de ensible a ionale o unde pin go e nmen in es men , and p o ide backg ound o e o s o commu-
nica e he se e i y o he issue.
• In e en ions on biological in asions in Sou h A ica a e occu ing wi hou a comp ehensi e policy o a s a egy o
guide and implemen such a policy. Exis ing and new policies only add ess pa o he issue o biological in asions.
A na ional s a egy is unde de elopmen .
• Fo mal p og ammes ha moni o p og ess owa ds educing he nega i e impac s o in asions (ou pu s and ou -
comes) a e no a ailable, bu , i es ablished, would allow o con ol measu es o be compa ed and imp o ed.
• Se e al gaps speci ic o he P ince Edwa d Islands we e iden i ied (e.g., in e ms o iden i ying incu sions and he
need o close co-ope a ion be ween managemen and esea ch); hese a e discussed in Chap e 5.
• The e has, o da e, been no sys ema ic e alua ion o how he epo is cu en ly used, wha can be done o imp o e
up ake, and how he epo can be e add ess s akeholde needs. B oad s akeholde engagemen exe cises ha e
been used e y e ec i ely in simila con ex s.
6.1 P og ess since he las epo
Fo each indica o , he e alua ion o he p og ess made owa ds ge ing an accu a e e lec ion o he ac ual si ua ion
was e alua ed by he epo au ho s based on he in o ma ion con ained in each chap e (Table 6.1).
Passi lo a cae ulea (© Alan Lo enzo).
102
103
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
a) Pa hway
indica o s
P og ess
2017–2019
P og ess
2020–2022
No es
1. Ra e o
un egula ed
in oduc ion
o new
species
minimal mode a e A da abase on his o ical in e cep ions o ag icul u al pes s
was ecen ly published, al hough his is s ill o be p ocessed
and included in he species lis . Wi h new indica o s being
de eloped, he e is a g ea e ecogni ion o he need o
sepa a e sea ch e o om obse a ions (Box 1.1). This
p omises o be an a ea whe e subs an ial p og ess can be
made.
1.1 In oduc ion
pa hway
p ominence
mode a e mode a e Recen esea ch on pa hways o in oduc ion means ha ou
unde s anding o ce ain pa hways, such as he pe ade and
medicinal plan ade, has imp o ed signi ican ly. Bu many
pa hways o in oduc ion emain poo ly s udied. A wo k low
has been de eloped o suppo his indica o .
1.2. In oduc ion
a es
mode a e mode a e While p og ess has been made (see indica o 1), he e a e
s ill signi ican gaps, e.g., in e ms o pa hways and da es o
in oduc ion. These da a a e being inco po a ed h ough he
new wo k low o add en ichmen da a o he species lis .
1.3 Wi hin-
coun y
pa hway
p ominence
none minimal The e ha e been insigh s in o ce ain pa hways due o
esea ch on he pe ade, medicinal plan ade and game
a ms, bu hese a e only a ew o he pa hways ac i e wi hin
Sou h A ica.
1.4 Wi hin-
coun y
dispe sal
a es
none mode a e A da abase o na i e-alien popula ions, including in o ma ion
on pa hways, has been cons uc ed. In o ma ion is also
a ailable o alien plan s in Sou h A ican Na ional Pa ks.
The pa hways o o he axa dispe sing wi hin he coun y,
howe e , emain unknown o he a ailable in o ma ion
needs o be colla ed.
Table 6 .1 . P og ess ga he ing in o ma ion equi ed o popula e he indica o s epo ed on in his epo : a) pa hway indica o s; b)
species indica o s; c) si e indica o s; and d) in e en ion indica o s (c . Figu e 0.3). The exac wo ding, he le el o knowledge and
in o ma ion gaps o he i s epo , he p oposed solu ion and he consequence i he gap is no illed a e p o ided in Table S6.1.
P og ess is sco ed as: eg ession – less in o ma ion is a ailable han p e iously; none – he in o ma ion is he same as in p e ious
epo s (wi h app op ia e upda es as needed); minimal – he e has been some mo e in o ma ion o p ocesses se up, bu hese
a e unlikely o be su icien o a ec he sco ing o he indica o s; mode a e – addi ional in o ma ion we e ob ained allowing o
some changes o be de ec ed o necessi a ing a e ised baseline; subs an ial – he p ocesses ha e seen a s ep change in wha
in o ma ion is a ailable and/o he in o ma ion ha could be ob ained. As he P ince Edwa d Islands chap e is new, he e was no
base-line o conside p og ess agains and i is no included below.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
b) Species
indica o s
P og ess
2017–2019
P og ess
2020–2022
No es
2. Numbe
o in asi e
species ha
ha e ‘Majo ’
impac s
minimal mode a e Imp o ed impac assessmen me hodologies ha e aided
in iden i ying highly impac ul species. The e is ongoing
de elopmen o amewo ks and models assessing po en ial
impac s and isks posed. The e is addi ional p og ess owa ds
de eloping s anda ds and assessing alien axa a a global
le el.
2.1 Numbe and
s a us o
alien species
subs an ial subs an ial The species lis has seen majo imp o emen s, wi h, in his
epo , clea e me ada a, he de elopmen o explici links
o axonomic backbones, and he p oduc ion o a wo k low
o adding species and en ichmen da a o he lis . The ocus
o he nex phase is o inc ease he numbe o da a-sou ces
inco po a ed in o he species lis and o o malise p ocesses
(e.g., o decla ing a axon alien and p esen ).
2.2 Ex en o
alien species
minimal minimal While in o ma ion om ci izen science pla o ms can be
use ul, he lack o ac i i y a ound he Sou he n A ican
Plan In ade s A las means ha a guably ou knowledge
o in asi e plan dis ibu ions has eg essed. Howe e ,
digi isa ion o eco ds h ough he Na ional Collec ions
Facili y and he F eshwa e Biodi e si y In o ma ion Sys em
ha e imp o ed he low o in o ma ion o p ima y eco ds
o na ional and in e na ional da abases. This is signi ican
p og ess. On balance he p og ess has been sco ed as
minimal.
2.3 Abundance
o alien
species
minimal none No addi ional p og ess has been made when compa ed o
he second epo .
2.4 Impac o
alien species
minimal minimal Imp o ed impac assessmen me hodologies ha e aided
in iden i ying highly impac ul species. The e is ongoing
de elopmen o amewo ks and models assessing po en ial
impac s and isks posed. The e is addi ional p og ess
de eloping s anda ds and assessing alien axa a a global
le el. Howe e , hese me hodologies ha e only been applied
o e y ew alien axa ound in Sou h A ica o da e.
Table 6 .1 . (Con inued) P og ess ga he ing in o ma ion equi ed o popula e he indica o s epo ed on in his epo : a) pa hway
indica o s; b) species indica o s; c) si e indica o s; and d) in e en ion indica o s (c . Figu e 0.3). The exac wo ding, he le el o
knowledge and in o ma ion gaps o he i s epo , he p oposed solu ion and he consequence i he gap is no illed a e p o-
ided in Table S6.1. P og ess is sco ed as: eg ession – less in o ma ion is a ailable han p e iously; none – he in o ma ion is he
same as in p e ious epo s (wi h app op ia e upda es as needed); minimal – he e has been some mo e in o ma ion o p ocesses
se up, bu hese a e unlikely o be su icien o a ec he sco ing o he indica o s; mode a e – addi ional in o ma ion we e ob-
ained allowing o some changes o be de ec ed o necessi a ing a e ised baseline; subs an ial – he p ocesses ha e seen a s ep
change in wha in o ma ion is a ailable and/o he in o ma ion ha could be ob ained. As he P ince Edwa d Islands chap e is
new, he e was no base-line o conside p og ess agains and i is no included below.
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The s a us o biological in asions and hei managemen in Sou h A ica in 2022
c) Si e
indica o s
P og ess
2017–2019
P og ess
2020–2022
No es
3. Ex en o
a ea ha
su e s ‘Majo ’
impac s om
in asions
minimal minimal Despi e se e al emo e sensing ini ia i es unde
de elopmen he e has s ill been li le angible p og ess.
3.1 Alien species
ichness
minimal none No p og ess has been made since he second epo .
3.2 Rela i e
in asi e
abundance
minimal none No p og ess has been made since he second epo .
3.3 Impac o
in asions
minimal mode a e
Economic es ima es o impac ha e been colla ed as pa o
his epo (c . Box 3.1), wi h an accompanying wo k low.
Some wo k has compa ed indica o s o he isk o ex inc ion
o he impac o alien species, howe e , he e is s ill a need o
look a o he measu es o impac (e.g., wa e loss and impac
on g azing po en ial) and o ensu e hese a e epea able.
d) In e en ion
indica o s
P og ess
2017–2019
P og ess
2020–2022
No es
4. Le el o
success in
managing
in asions
minimal none A ecen analysis o he e ec i eness o con ol (Van Wilgen
e al. 2022a) p o ided some use ul es ima es o he e o
aken, bu se ed o highligh he lack o moni o ing o
con ol e ec i eness meaning ha his indica o could no
be calcula ed.
Table 6 .1 . (Con inued) P og ess ga he ing in o ma ion equi ed o popula e he indica o s epo ed on in his epo : a) pa hway
indica o s; b) species indica o s; c) si e indica o s; and d) in e en ion indica o s (c . Figu e 0.3). The exac wo ding, he le el o
knowledge and in o ma ion gaps o he i s epo , he p oposed solu ion and he consequence i he gap is no illed a e p o-
ided in Table S6.1. P og ess is sco ed as: eg ession – less in o ma ion is a ailable han p e iously; none – he in o ma ion is he
same as in p e ious epo s (wi h app op ia e upda es as needed); minimal – he e has been some mo e in o ma ion o p ocesses
se up, bu hese a e unlikely o be su icien o a ec he sco ing o he indica o s; mode a e – addi ional in o ma ion we e ob-
ained allowing o some changes o be de ec ed o necessi a ing a e ised baseline; subs an ial – he p ocesses ha e seen a s ep
change in wha in o ma ion is a ailable and/o he in o ma ion ha could be ob ained. As he P ince Edwa d Islands chap e is
new, he e was no base-line o conside p og ess agains and i is no included below.
112
The s a us o biological in asions and hei managemen in Sou h A ica in 2022
The d a ing eam would like o hank he membe s o he Re e ence and Ad iso y Commi ee o hei guidance and
ad ice on he p ocess o compiling his hi d s a us epo , and o e iewing all he d a s o he epo (see page ii o a
lis o hose in ol ed). In addi ion, he ollowing a e hanked o hei insigh ul commen s on d a s o he s a us epo
and he summa y o key messages: Albe Chakona, Alex Ma sh, And ew Tu ne , Andy Sheppa d, Ca ol Poole, Claude e
James, Clin on Ca bu , Cos as Zacha iades, Da id Whi elaw, Dewidine an de Col , Diana Rod íguez Cala, Domi illa
Raimondo, E ol Douwes, Gio anni Vime ca i, Iain Pa e son, John Sco che , Koeb aa Pe e s, Lesley Hende son, Li hu-
wani Nnze u, Lize on S aden, Londiwe Mokeona, Ma in Hill, Mashudu Vic o Phalanndwa, Mlungele Nsikani, Nicholas
Cole, Philip I ey, Sab ina Kumschick, Sa ah Da ies, Sji k Gee s, Thenjiwe Si hole and Wa en Schmid .
The Sou h A ican Depa men o Fo es y, Fishe ies and he En i onmen (DFFE) p o ided he unding o his epo ,
no ing ha his epo does no necessa ily ep esen he iews o opinions o DFFE o i s employees. The wo k on indi-
ca o s was assis ed h ough sTWIST, which was suppo ed by sDi , he iDi Syn hesis Cen e (DFG FZT 118, 202548816).
Acknowledgemen s
The d a ing eam o he hi d s a us epo ( om le o igh ): Whi ney Engelb ech , Ka elyn Faulkne , A iwe Si uba, Emily McCulloch-
Jones, Lau a Fe nández Winze , Tsungai Zengeya, Siyasanga Miza, Fa ai Te e ai, and John Wilson. Inse : B ian an Wilgen.
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