The status of biological invasions and their management in South Africa in 2022 [FIRST DRAFT FOR PUBLIC COMMENT]

The Status of Biological Invasions and their Management in South Africa in 2022 [FIRST DRAFT FOR PUBLIC COMMENT] i Note to reader 1 We are inviting you to submit comments, corrections, and queries on this third status report on 2 biological invasions1. We have prepared a standard form for commenting that you can fill in if you 3 wish, but if you would prefer to send in your inputs in your own format, please indicate the page and 4 line numbers to which your comment refers. Many of the technical details (and data on which the 5 report is based like the list of alien species) are available in the appendices and supplementary 6 material (links available on the last page). Please also consider commenting on these. If you are in a 7 position to provide additional information, we would be very grateful, and will aim to ensure all 8 contributors are appropriately acknowledged. If you do not wish to be named, please let us know. We 9 would like as many people and organisations to make inputs as possible, so please pass the report on 10 to anyone you think might be able to contribute. We will capture all comments received during this 11 commenting period and track how they are responded to. A database of these comments and the 12 responses will be available on request once the report has been released. 13 Comments to be sent to: [email protected] By: 28 February 2023 14 Form for commenting: https://tinyurl.com/mr2mu6xz 15 This is a “first draft for public comment”. It outlines the format and sections of the intended report, 16 and provides some preliminary findings, but many of the estimates of indicator values will change as 17 a result of ongoing analysis, and because of inputs received during this review period. In particular 18 the report will be based on information up to the end of December 2022, this of course was not 19 possible in this draft. Therefore the results should viewed as demonstrative of what the final report 20 will look like rather than indicative of the current state. Footnotes are added to the text to indicate 21 where additional analyses are pending. 22 Thank you in advance for your comments, this report relies on the active participation of a wide range 23 of stakeholders, and we appreciate you taking the time to engage with us. 24 Yours sincerely, 25 Dr Tsungai Zengeya (on behalf of the third status report drafting team) 26 Kirstenbosch, 20 December 2022 27 1The previous status reports are available to download at http://iasreport.sanbi.org.za/ , links for on-line resources are available at end of this report. ii Citing this publication 28 For citations in the scientific literature: Zengeya, T.A. & Wilson, J.R. (Eds.), 2022. The status of 29 biological invasions and their management in South Africa in 2022 [FIRST DRAFT FOR PUBLIC 30 COMMENT]. South African National Biodiversity Institute, Kirstenbosch and DSI-NRF Centre of 31 Excellence for Invasion Biology, Stellenbosch. http://dx.doi.org/10.5281/zenodo.7414804 32 33 For citations in policy documents: SANBI and CIB 2022. The status of biological invasions and their 34 management in South Africa in 2022 [FIRST DRAFT FOR PUBLIC COMMENT]. South African National 35 Biodiversity Institute, Kirstenbosch and DSI-NRF Centre of Excellence for Invasion Biology, 36 Stellenbosch. http://dx.doi.org/10.5281/zenodo.7414804 37 38 ISBN: to be included in the final report 39 40 Authors 41 Lead editors: Tsungai A. Zengeya, John R. Wilson 42 Chapter lead authors: Katelyn T. Faulkner; Laura M. Fernandez Winzer; Michelle Greve; Siyasanga 43 Miza; Emily J. McCulloch-Jones; Peter C. le Roux; Marthán Theart; Brian W. van Wilgen; John R. 44 Wilson & Tsungai A. Zengeya 45 With contributions (to date) from: Julie A. Coetzee; Nicholas Cole; Whitney Engelbrecht; Martin P. 46 Hill; Carol Jacobs; Sabrina Kumschick; Debbie Muir; Wilma Nel; Leoni Pretorius; Roger Price; Tamara 47 B. Robinson; Aviwe Sifuba; Louise Stafford; Andrew A. Turner; Karabo Wanjau; Andrew Wannenburgh; 48 Anton Wolfaardt; Costas Zachariades 49 The authorship list is expected to expand in the next draft. 50 51 iii 52 Note to reader ....................................................................................................................................................................... i 53 Citing this publication ........................................................................................................................................................... ii 54 Authors ................................................................................................................................................................................. ii 55 Contents ................................................................................................................................................................................... iii 56 Preface by SANBI CEO .............................................................................................................................................................. iv 57 List of acronyms ....................................................................................................................................................................... iv 58 Glossary ..................................................................................................................................................................................... v 59 Executive summary ................................................................................................................................................................... x 60 Key findings and gaps ............................................................................................................................................................ x 61 Trends in indicators............................................................................................................................................................... x 62 Chapter 1: Introduction............................................................................................................................................................. 1 63 1.1 The importance of biological invasions to South Africa .................................................................................................. 1 64 1.2 The mandate, purpose, and structure of the third status report .................................................................................... 1 65 1.3 Process for the compilation of the report ...................................................................................................................... 3 66 1.4 Indicators ........................................................................................................................................................................ 7 67 1.5 Workflows and protocols ................................................................................................................................................ 7 68 1.6 Aspects of biological invasions that are not covered ...................................................................................................... 8 69 Chapter 2: Pathways ............................................................................................................................................................... 10 70 2.1 Introduction pathway prominence ............................................................................................................................... 11 71 2.2 Introduction rates ......................................................................................................................................................... 12 72 2.3 Within-country pathway prominence ........................................................................................................................... 15 73 2.4 Within-country dispersal rates ...................................................................................................................................... 16 74 Box 2.1. Work towards improving the pathways indicators ............................................................................................... 17 75 2.5 Trends in pathway indicators ........................................................................................................................................ 20 76 Chapter 3: Species ................................................................................................................................................................... 22 77 3.1 Number and status of alien species .............................................................................................................................. 23 78 3.2 Extent of alien species................................................................................................................................................... 24 79 3.3 Abundance of alien species ........................................................................................................................................... 25 80 3.4 Impact of aliens ............................................................................................................................................................. 25 81 Box 3.1 Native-alien populations ........................................................................................................................................ 26 82 3.5 Trend in species indicators ............................................................................................................................................ 28 83 Chapter 4: Sites ....................................................................................................................................................................... 30 84 4.1 Alien species richness ................................................................................................................................................... 31 85 4.2 Relative invasive abundance ......................................................................................................................................... 35 86 4.3 Impact of invasions ...................................................................................................................................................... 35 87 4.4 Trends in sites indicators .............................................................................................................................................. 37 88 Chapter 5: Interventions ......................................................................................................................................................... 38 89 5.1 Input—quality of the regulation framework ................................................................................................................. 40 90 5.2 Input—money spent ..................................................................................................................................................... 43 91 5.3 Input—planning coverage ............................................................................................................................................. 47 92 5.4 Output—pathways treated ........................................................................................................................................... 49 93 5.5 Output—species treated ............................................................................................................................................... 50 94 5.6 Output—sites treated ................................................................................................................................................... 52 95 5.7 Outcome—effectiveness of pathway treatments ......................................................................................................... 52 96 5.8 Outcome—effectiveness of species treatments ........................................................................................................... 53 97 5.9 Outcome—effectiveness of site treatments ................................................................................................................. 54 98 Box 5.1 The Greater Cape Town Water Fund...................................................................................................................... 55 99 Box 5.2 Successful biological control of water hyacinth on a eutrophic sub-tropical water-body ..................................... 56 100 5.11 Trends in interventions indicators .............................................................................................................................. 58 101 Chapter 6: The status of biological invasions and their management in the Prince Edward Islands.................................... 62 102 6.1 Pathways ....................................................................................................................................................................... 63 103 6.2 Species .......................................................................................................................................................................... 68 104 6.3 Sites ............................................................................................................................................................................... 71 105 6.4 Interventions ................................................................................................................................................................. 72 106 6.5 Trends in indicators ....................................................................................................................................................... 78 107 Chapter 7: Gaps ....................................................................................................................................................................... 79 108 Acknowledgements ................................................................................................................................................................. 79 109 References ............................................................................................................................................................................... 79 110 Links to supplementary material and appendices ................................................................................................................. 87 111 112 113 iv Preface by SANBI CEO 114 To be added—a preface will be drafted and finalised by in 2023. The preface will outline the purpose 115 of report, the scope, legal requirement, principal findings, and their implications. 116 List of acronyms1 117 ASRARP Alien Species Risk Analysis Review Panel 118 A&IS Alien and Invasive Species as referred to either in the regulations or the regulatory lists 119 published under the auspices of the National Environmental Management: Biodiversity 120 Act 121 CBD the Convention on Biological Diversity of the United Nations 122 CIB the Department of Science and Innovation-National Research Foundation Centre of 123 Excellence for Invasion Biology 124 DALRRD Department of Agriculture, Land Reform and Rural Development 125 DFFE Department of Forestry, Fisheries, and the Environment 126 EICAT Environmental Impact Classification for Alien Taxa 127 hmgc half-minute grid cell (used for mapping on the Prince Edward Islands) 128 NEM:BA the National Environmental Management: Biodiversity Act (Act No. 10 of 2004) 129 NEM:BA A&IS: see A&IS 130 NRM Natural Resource Management (a division of the DFFE) 131 PEIs the Prince Edward Islands 132 qdgc quarter-degree grid cell 133 RAC the Reference and Advisory Committee (of this third status report) 134 SANBI the South African National Biodiversity Institute 135 SAPIA the southern African Plant Invaders Atlas 136 SEICAT Socio-Economic Impact Classification for Alien Taxa 137 WfW Working for Water 138 ZAR South African Rands 139 140 1 These acronyms are used either in this report or in the supplementary material. For editorial conventions see supplementary material S1.1. v Glossary1 141 Abundance (cf. distribution, extent): a measure of the number of individuals, coverage, or biomass of 142 an organism in a specified site. 143 Adaptive management: a structured, iterative process that includes the setting of goals, regular 144 monitoring of progress towards the achievement of those goals, and, based on the findings of the 145 monitoring, the adaptation of management to improve its effectiveness or a revision of the goals. 146 Adaptive management is useful where the outputs and outcomes of management are uncertain, and 147 where an approach of learning-by-doing can reduce uncertainty over time. 148 Alien species (cf. extralimital, native species): a species that is present in a site outside its natural 149 range as a result of human action that has enabled it to overcome biogeographic barriers. 150 Assessment: a critical evaluation of information. 151 Benefit: cost ratio: see returns on investment 152 Biodiversity: the variability among living organisms from all sources including terrestrial, marine, and 153 other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity 154 within species, between species and of ecosystems. 155 Biological invasions: the phenomenon of, and suite of processes that are involved in determining, the 156 transport of organisms to sites outside their native range by human activities and the fate of the 157 organisms in their new ranges. 158 Biological control (syn. biocontrol): the use of specimens of one species for the purpose of preying 159 on, parasitizing on, damaging, killing, suppressing or controlling a specimen of another species. 160 Biocontrol: see Biological control. 161 Biome: a large naturally occurring community of plants and animals that have common characteristics 162 in similar physical environments, e.g., desert or forest. 163 Biosecurity: measures that are taken to stop the introduction or dispersal of organisms harmful to 164 human, animal, or plant life. 165 Contested species: alien species for which there is dispute about the appropriate (if any) regulatory 166 listing. Also referred to as conflict-generating species. Such species have in some cases been listed as 167 category 2 under the NEM:BA A&IS Regulations, whereby a permit can be issued to stakeholders to 168 conduct otherwise illegal activities with the listed alien species. The contestation may thereby be 169 resolved. 170 Compliance: The action or fact of complying with instructions, in this second report such instructions 171 primarily refer to the provisions of NEM:BA. 172 Compliance notice (also pre-compliance notice): an official document served by an environmental 173 management inspector on a person when there are reasonable grounds for believing that that person 174 has not complied with a provision of the law or with a term or condition of a permit, authorisation or 175 other instrument issued in terms of such law. A pre-compliance notice is a written notice of intention 176 1These definitions are based on those in the second report, Richardson et al. (2011), Wilson et al. (2017b), and van Wilgen et al (2020a) with consideration of definitions given in relevant South African and international legislation, specifically the NEM:BA and its A&IS Regulations, and the CBD ( https://www.cbd.int/invasive/terms.shtml). These cover terms used in this third report and in the supplementary material to the third report. For editorial conventions see supplementary material S1.1. vi to issue a compliance notice, which precedes the issuing of a compliance notice and invites the person 177 to whom it has been issued to make representations to the environmental management inspector. 178 Containment: the goal of preventing or reducing the spread of invasive species. 179 Contaminant: the accidental introduction of an alien species with an intentionally transported 180 commodity with which the organism has a specific, natural association. 181 Control: any action taken to prevent the recurrence, re-establishment, re-growth, multiplication, 182 propagation, regeneration or spreading of an alien species. 183 Conviction: a verdict of guilty issued by a competent court following the prosecution of a person 184 suspected of having committed a criminal offence. 185 Corridor: the natural spread of an alien species into a new region through a human-constructed 186 transport infrastructure that connects previously unconnected regions, and in the absence of which 187 dispersal would not have been possible. 188 Directive (also pre-directive): an official document served by an environmental management 189 inspector on a person when such person is: a) a permit holder and is suspected of not complying with 190 the conditions under which a permit has been issued or not taking all the required steps to prevent or 191 minimise harm to biodiversity by the alien species to which the permit relates; or b) a landowner and 192 is suspected of not fulfilling their duty of care in relation to listed alien species on their land. A directive 193 directs a person to take steps to remedy harm caused to biodiversity caused by such person’s non-194 compliance or failure to fulfil the landowner’s duty of care. A pre-directive is a written notice of 195 intention to issue a directive, which precedes the issuing of a directive and invites the person to whom 196 it is issued to make representations to the environmental management inspector. 197 Dispersal (syn. spread): movement of organisms within a defined site that is facilitated either 198 intentionally or accidentally by humans, or that occurs naturally. 199 Distribution: the extent and abundance of a species over a given site. 200 Eradication: the complete removal of all individuals and propagules of a population of an alien species 201 from a particular site to which there is a negligible likelihood of reinvasion. 202 Escape (cf. release): the spread of an alien species that was intentionally introduced and kept in 203 captivity or cultivation to sites outside of captivity or cultivation. Includes both natural spread and the 204 accidental or intentional illegal human-mediated dispersal of live organisms from the site of captivity 205 or cultivation. 206 Established: see naturalised. 207 Extent (cf. abundance, distribution): the broad-scale area over which an organism occurs. The spatial 208 scale over which extent is measured needs to be specified. The occupancy of sites at a fine-spatial 209 scale is often equivalent to the abundance. 210 Extirpation (cf. eradication): the result of a control operation whereby all individuals in a population 211 are removed. Other populations might be close by or pathways of introduction and dispersal are still 212 operating such that the probability of re-invasion is probable or not known. 213 Extralimital (cf. alien species, native species): a native species that has been introduced by humans 214 to a part of South Africa that is outside of the species’ native distribution range. It does not include 215 native species that have extended their distribution by natural dispersal. 216 Impact: the effect of an alien species on the physical, chemical, and biological environment. It can 217 include both negative and positive effects. 218 vii Incursion: an isolated population of a pest, weed, or alien species, that usually has a limited spatial 219 extent and has been recently detected at a site. In general, the management of incursions is referred 220 to as incursion response. 221 Indicator: a set of measurements that give specific information about the state of something. 222 Indigenous species: see Native species. 223 Interventions: the full variety of actions taken in response to biological invasions, including direct 224 actions, i.e., control, and indirect actions like monitoring, regulation, and research. 225 Introduced: see Introduction. 226 Introduction: the movement of an alien species (either accidentally, intentionally and legally, or 227 intentionally and illegally) by human activity, to a region outside its native range. Introductions can 228 also refer to species which were introduced to one country by humans and spread naturally to 229 neighbouring countries. In the context of introductions, the term ‘accidental’ is preferred to the 230 synonymous term ‘unintentional’. 231 Invasion: see Biological invasions. 232 Invasion debt: the potential increase in biological invasions at a site over a particular time frame in 233 the absence of any interventions (Rouget et al., 2016). It is composed of the number of new species 234 that will be introduced (introduction debt), the number of species that will become invasive (species-235 based invasion debt); the increase in area affected by invasions (area-based invasion debt); and the 236 increase in the negative impacts caused by introduced species (impact-based invasion debt). 237 Invasive alien species: see Invasive species. 238 Invasive species: Alien species that sustain self-replacing populations over several life cycles, produce 239 reproductive offspring, often in very large numbers at considerable distances from the parent and/or 240 site of introduction, and have the potential to spread over long distances. 241 Invasiveness: the features of an alien organism, such as their life-history traits and modes of 242 reproduction, that define their capacity to become an invasive species. 243 Listed alien species: species which are listed under the NEM:BA A&IS Regulations either as ‘listed 244 invasive species’ (which are intended to only include alien species that are present in South Africa) or 245 ‘prohibited alien species’ (which are intended to only be species that are absent from South Africa). 246 Monitoring: a systematic process of collecting and analysing information to track progress towards 247 reaching stated goals, that facilitates the assessment of the efficacy of interventions. 248 Native-alien populations: a population of a taxon that is native to a part of South Africa, but that was 249 founded by individuals moved by direct human agency, over a biogeographical barrier, to an area 250 beyond the species’ native range (i.e., it can be considered a biological invasions) (see Box 3.1). 251 Native species (syn. indigenous species, cf. alien species, extralimital): species that are found within 252 their natural range where they have evolved without human intervention (intentional or accidental). 253 Also includes species that have expanded their range as a result of human modification of the 254 environment that does not directly impact dispersal (e.g., populations are still considered native if 255 they result from an increase in range as a result of watered gardens, but are considered alien if they 256 result from an increase in range as a result of spread along human-created corridors linking previously 257 separate biogeographic regions). 258 Naturalised (syn. established): Alien species that sustain self-replacing populations for several life 259 cycles or over a given period of time without direct intervention by people, or despite human 260 intervention. 261 viii Natural dispersal: the dispersal of an alien species through natural spread from a region where it was 262 previously introduced through human assistance or action, to another region where it is not native. 263 Pathway: a broadly defined term that refers to the combination of processes and opportunities that 264 result in the movement of alien species from one place to another. 265 Permit: an official document issued in terms of Chapter 7 of National Environmental Management: 266 Biodiversity Act, 2004 (Act no. 10 of 2004). 267 Pest: an organism that causes negative impacts. The affected sector might be specified, so an 268 agricultural pest will impact negatively on agricultural production. Pests can be alien or native species, 269 and are usually taken to refer to animals, with pest plants often rather referred to as weeds and pest 270 fungi or microbes referred to as diseases. 271 Policy: a high-level overall plan, adopted by the Executive Authority, for achieving identified outcomes 272 through specified methods or principles that guide decision-making. A policy on biological invasions 273 would be a high-level plan which identifies goals concerning biological invasions in South Africa and 274 identifies the interventions that should be used to achieve those goals. 275 Pre-compliance notice: see compliance notice. 276 Pre-directive: see directive. 277 Propagule pressure: a concept that encompasses variation in the quantity, quality, composition and 278 rate of supply of alien organisms resulting from the transport conditions and pathways between 279 source and recipient regions. 280 Prosecution: the institution and conducting of legal proceedings, usually by the State, against a person 281 suspected of having committed a criminal offence. 282 Port of entry: an official point of entry or departure from South Africa through which goods and people 283 may enter or leave a country, for example a border post, airport or harbour. 284 Regulation: 1) a law or rule made by the Executive Authority in terms of original legislation to regulate 285 conduct (in this case the NEM:BA A&IS Regulations); 2) the act of regulating, i.e., to govern or direct 286 according to rule, or to make regulations (authoritative rules) for certain conduct. 287 Regulatory lists/listing: a list of alien species that are regulated under the NEM:BA A&IS Regulations1. 288 Release (cf. escape): the intentional introduction of an alien species to a site outside of captivity or 289 cultivation. This refers to both legal and illegal introductions, however if a legally introduced alien 290 species is illegally released outside of captivity or cultivation then it is classified as an escape. 291 Returns on investment: the amount of value that is gained as a result of a particular amount spent on 292 an intervention. This can be calculated as a benefit: cost ratio whereby each rand spent (the cost) is 293 set against the amount of rands gained (benefit). An intervention is technically cost-effective if the 294 benefit: cost ratio is greater than one, although more generally cost effectiveness is about maximising 295 the ratio. 296 Risk: The likelihood and consequence of an event, in this second report the event is a biological 297 invasion 298 Risk analysis: The process of identifying and assessing the likelihood and consequence of an event, as 299 well as considerations as to how to manage and communicate the risk (see Figure S5.1). 300 Risk assessment: a component of risk analysis that focuses on evaluating the likelihood and 301 consequence of an event taking place. In the context of this second report, such an event is the 302 1Definitions of the regulatory categories and the numbers in each category will be provided in the second order draft. For information from the second report see Table 5.2 and Supplementary Material S5.2 therein. 4 September 2022, and discussed at the second meeting of the RAC on 28 September 2022. The report 446 was revised and set out for public comment on 20 December 2022. The RAC reviewed the next draft 447 produced, before there was a second round of public comment. The Chair of the RAC also reviewed 448 how the comments received during all rounds of review were addressed, i.e., acted in a review editor 449 role. Finally, the RAC intends to provide advice both in terms of the public release of the report, and 450 on reflecting on the process. 451 Collate and review available information: Information was incorporated into the report primarily from 452 published literature and unpublished information provided by stakeholders. Information contained in 453 the report is based on data available to the report writing team as of the end of December 2022 (Box 454 1.1). 455 Stakeholder engagement: Stakeholder engagement was an on-going process linked to the other 456 activities. Initially the drafting team engaged directly with specialist contributors to obtain information 457 that was not readily accessible and identified stakeholders to be contacted for input and review. 458 Contributors were identified initially based on those identified previously, and those who provided 459 comments were asked for updates. New potential contributors were contacted on an ad hoc basis as 460 information became available and in response to the public consultation. Contributors came from 461 academic institutions; research institutes and science councils; national, provincial, and local 462 government departments; and from private individuals whom were interested and affected. 463 Contributions from the identified stakeholders were in the form of data provision and commenting on 464 drafts. 465 All feedback was recorded and the comments responded to in line with international best practice 466 (IPBES 2018). The inputs and responses to the requests for review, were documented and are available 467 for scrutiny from SANBI on request. 468 469 5 470 Figure 1.1 Key steps in the production of the report ‘the Status of Biological Invasions and their 471 Management in South Africa in 2022’. The Minister is the South African Minister of Forestry, Fisheries 472 and the Environment; the RAC is the research and advisory committee; and SANBI is the South African 473 National Biodiversity Institute. 474 Status report team review the release of the 2 nd report and identify workflows needed for the 3 rd report (Jun–Dec 2021) Collate and review available information Identify and engage specialist contributors Reference and advisory committee Assign values to indicators Draft for public comment (Dec 2022) Stakeholder engagement Identify stakeholders Stakeholder review (Dec 2022–Feb 2023) Produce revised draft (Apr 2023) Expert review ( May–Jun 2023 ) Production of report (Aug 2023) Media enquiries Submit to SANBI Board (Sep 2023) Submit to Minister (Oct 2023) Public release (Jan 2024) Reflect on the process Draft table of contents (Feb 2022) Meeting (22 Feb 2022) Appoint a RAC (Jan 2022) Conference and workshop presentations Review draft Review of revised draft, and response to comments received Meeting (~Dec 2023) Stakeholder review (Jun–Jul 2023) Check responses to comments received 2 nd status report finalised (2 Nov 2020) 2 nd status report launched (28 May 2021) Engage with government on their response to key findings (Oct–Dec 2023) Produce draft report (Sep 2022) Meeting (28 Sep 2022) Meeting (~Jun 2023) Produce revised draft (Jun 2023) 6 Produce and review of draft reports: A draft was completed in September 2022 and sent to the RAC 475 for internal review. This was then discussed at a meeting of the RAC on 28 September, revised, and 476 sent out for public review by experts and stakeholders for a period of about 8 weeks (December 2022–477 February 2022). The request for review was submitted to a South African list server on biological 478 invasions ([email protected]), heads of relevant national and provincial government 479 departments, heads of relevant academic departments and institutions, and professional societies and 480 forums (including the Royal Society of South Africa; the Akademie vir Wetenskap en Kuns; the 481 Zoological, Entomological, and Botanical Societies; Birdlife South Africa; and the Wildlife and 482 Environment Society of South Africa). A copy of the first draft for public comment was attached to the 483 formal notice and was available for download online (http://dx.doi.org/10.5281/zenodo.7414804) 484 In May 2023, the next draft of the report was produced and circulated to two independent experts 485 from South Africa, and one international expert, as well as members of the RAC (link to be added). 486 Their comments were addressed and a second draft for public comment was circulated as before 487 (June–July 2023). 488 Comments were received from …1 across the two rounds of review. 489 Produce and release the final report: A complete version of the report was sent in August 2023 to the 490 SANBI Graphics team for editing, layout, design, and printing and then submitted to the SANBI Board 491 in September 2023 for their consideration. After board approval, the SANBI CEO submitted the report 492 to the Minister of Forestry, Fisheries and the Environment. At the same time a copy of the report was 493 submitted to the DFFE and the DALRRD as the key receivers of the report. This provided the 494 departments with an opportunity to prepare for responding to media enquiries or public concerns 495 raised and to seek clarification from the report drafting team as needed, noting that no changes could 496 be made to the report during this period. To maximise publicity and media uptake of the report, the 497 report is intended to be released to the public in early January 2024 in time for the fresh news cycle 498 of the year. As with previous reports, information will be included in the South African State of the 499 Environment Report process (http://soer.environment.gov.za/soer/). 500 Reflect on the process: After the public release of the report the status report team will convene a 501 meeting with key stakeholders (including members of the RAC) to reflect on the process used to 502 compile the report and to identify areas of improvement for subsequent reports. 503 1the number of people and institutions commenting to be added later. 7 1.4 Indicators 504 This report is structured around the 20 indicators and 4 high-level indicators outlined in Wilson et al. 505 (2018) (Figure 1.2) and adheres broadly to the published indicator factsheets1. However, there have 506 been slight updates and corrections to how some things were scored, and so the indicators should be 507 read in concert with the metadata to the species list and other workflows, with the more recent 508 documents taking precedence. Specifically, the technical details on scoring the indicators and the high-509 level indicators are available in the supplementary material. Fully revised and updated indicator 510 factsheets will be provided together with the next report. 511 512 Figure 1.2 Indicators used in the report (based on Wilson et al. 2018). 513 Notably, the baselines proposed in previous reports needed to be revised in some instances (e.g., due 514 to errors in the original values). This means that it is not always appropriate to compare values 515 between the reports, and in some cases the report calculated the values that should have been in 516 previous reports. Changes over time from these revised baselines are presented and discussed in this 517 report, and differences in the calculation methods used between the reports are noted in the 518 supplementary material. 519 1.5 Workflows and protocols 520 Given the need for a repeatable, transparent process, various workflows were identified and 521 constructed to outline how the report was put together and to inform future report production. These 522 1The indicator factsheets can be downloaded at: https://tinyurl.com/5n6fbymh 5. Number and status of alien species 6. Extent of alien species 7. Abundance of alien species SPECIES SITES 9. Alien species richness 10. Relative invasive abundance PATHWAYS 1. Introduction pathway prominence 3. Within-country pathway prominence INTERVENTIONS 2. Introduction rates 4. Within-country dispersal rates 18. Effectiveness of pathway treatments OUTCOMES 8. Impact of alien species 11. Impact of invasions 19. Effectiveness of species treatments 20. Effectiveness of site treatments 15. Pathways treated OUTPUTS 16. Species treated 17. Sites treated 12. Quality of regulatory framework INPUTS 13. Money spent 14. Planning coverage HIGH LEVEL A. Rate of unregulated introduction of new species HIGH LEVEL B. Number of invasive species that have major impacts HIGH LEVEL C. Extent of area that suffers major impacts from invasions HIGH LEVEL D. Level of success in managing invasions 8 are discussed in the relevant chapters and presented in full in Appendix 4. They are listed here for 523 reference1: 524 • Introduction pathway prominence 525 • Tracking data sources 526 • Adding alien taxa and enrichment data to the species list 527 • Processing occurrence records to give species richness and abundance estimates at different 528 spatial units 529 • Alien taxa impact assessments 530 • Impacts on key ecosystem services 531 • Regulatory processes 532 • Money spent 533 • Evaluating control plans and their implementation 534 • Compliance and inspections and court cases 535 Mirroring the above workflows, a workflow was also established for sourcing, capturing, and reporting 536 information for the Prince Edward Islands (Chapter 6). 537 Some of these workflows required specific protocols where the intention is for these to be applied 538 outwith the report. For example, a protocol has been set up to classify native-alien populations 539 (Nelufule et al. 2022, Box 3.1). 540 1.6 Aspects of biological invasions that are not covered 541 The aspects not covered in this report are largely the same as those not covered in previous reports 542 (see supplementary material S1.6). The report recognises that COVID-19 has had profound impacts on 543 the lives of South Africans, but as no explicit analysis of the effect of the pandemic was available, the 544 impact of the lockdown on biological invasions is not considered here, except where there were 545 palpable impacts on the indicators (e.g., the significant drop in trade and travel affected the indicators 546 on introduction pathway prominence and within-country pathway prominence, cf. Figure S2.19) 547 548 1for this draft only three workflows are included: ‘Introduction pathway prominence’; ‘Tracking data sources’; and ‘Adding alien taxa and enrichment data to the species list’ 9 Box 1.1 The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services 549 (IPBES) thematic assessment of invasive alien species and their control (IAS Assessment) 550 The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is an 551 independent intergovernmental body established by States to strengthen the science-policy interface 552 for biodiversity and ecosystem services for the conservation and sustainable use of biodiversity, long-553 term human well-being and sustainable development. In 2018, a global IAS Assessment was initiated 554 and is to be presented to the IPBES plenary in May 2023 for approval by the parties to IPBES. The aim 555 of the IAS Assessment “is to critically evaluate available evidence on the severity of the threat of 556 biological invasions to underpin potential options for decision-making.”. The report is due to be 557 released to the public as part of the 10th IPBES Plenary that is due to run 28 August–2 September 2023. 558 As such it was not possible to include the findings in this third report. For details see 559 https://ipbes.net/invasive-alien-species-assessment 560 561 Box 1.2 The proposed Convention on Biological Diversity (CBD) target on biological invasions and 562 indicators to track this 563 One purpose of this report is to facilitate South Africa’s reporting to international bodies on biological 564 invasions, including to the CBD. As such the aim is to align this report with inter-governmental 565 reporting processes and indicators. However, while there has been significant progress and the need 566 for a target on biological invasions has been agreed, the CBD is, as of 1 December 2022, still to finalise 567 the wording for the 2030 and 2050 targets (Essl et al. 2020). 568 Parallel to this process there has been significant research globally into the most appropriate 569 indicators. For example, the working group sTwist “Theory and Workflows for Alien and Invasive 570 Species Tracking” (https://www.idiv.de/en/stwist.html) has proposed three indicators (McGeoch et 571 al. 2021). Rate of Invasive Alien Species Spread provides modelled rates of ongoing introductions of 572 species based on invasion discovery and reporting. Impact Risk estimates invasive species impacts on 573 the environment in space and time and provides a basis for nationally targeted prioritization of where 574 best to invest in management efforts; and Status Information on invasive alien species tracks 575 improvement in the essential dimensions of information needed to guide relevant policy and data 576 collection and in support of assessing invasive species spread and impact. 577 The applicability of these indicators to the South Africa context, and how they relate to the indicator 578 framework used in this report will be a focus of future reports. 579 580 10 Chapter 2: Pathways 581 Lead authors: Katelyn T. Faulkner, John R. Wilson 582 Contributing authors: Martin P. Hill, Wilma Nel, Leoni Pretorius, Tamara B. Robinson, Costas 583 Zachariades 584 Key findings 585 ● The trade and travel controls put in place to prevent the spread of Covid-19 had a short-lived, 586 quantitative, but not qualitative, impact on the opportunities provided by some pathways for 587 introductions. Introduction opportunities are diverse and are returning to pre-pandemic 588 levels. 589 ● New alien organisms continue to be legally, and illegally or accidentally introduced every year. 590 The rate of illegal and accidental introductions does not appear to have recently changed. 591 ● Native species are being moved and introduced to parts of the country where they are not 592 native. Most of these native-alien populations are ornamental plants, and mammals 593 introduced to game farms to attract tourists, but accidental introductions are also occurring, 594 particularly with transported plants or their products, and with land vehicles and boats. 595 ● Alien organisms are being accidentally moved into the country’s protected areas, with recent 596 emphasis on visitors’ shoes, and vehicles as a source of alien propagules. 597 Key gap 598 ● There is insufficient information on how invasive species move and are moved around South 599 Africa. A system to track within-country movement is required if South Africa is to manage the 600 spread of invasive species. 601 Indicators covered in this chapter 602 603 For all pathways indicators, the pathway classification framework of the Convention on Biological 604 Diversity is implemented (CBD 2014), with proposed changes by Harrower et al. (2018). Specific details 605 of values are provided in Appendix 5 and methodological changes from previous reports and details 606 of how the calculations were made are outlined in the Supplementary Materials (e.g., Table S2.1). 607 PATHWAYS 1. Introduction pathway prominence 3. Within-country pathway prominence 2. Introduction rates 4. Within-country dispersal rates HIGH LEVEL A. Rate of unregulated introduction of new species 11 2.1 Introduction pathway prominence 608 Introduction pathway prominence assesses, based on socio-economic data, the opportunities 609 available for alien organisms to be introduced to South Africa from other countries. Providing effective 610 biosecurity measures are in place, a large or increasing introduction pathway prominence is not, in 611 and of itself, undesirable in terms of biological invasions, as this indicator does not consider how many 612 introductions these opportunities have resulted in. 613 There has been a >10% decline, over the period 2020–2022, in the introduction opportunities provided 614 by 14 of the 44 introduction pathways. For example, the value of forestry product imports decreased 615 by ~35%, the number of aircraft arrivals from international and regional destinations declined by 43%, 616 and the number of people entering the country declined by 78%. The controls placed on trade and 617 travel to prevent the spread of Covid-19 drove these trends. However, for all these pathways the 618 changes are likely to be short-lived, and are not large enough to have a qualitative impact on the 619 indicator (e.g., whether introduction pathway prominence is major or moderate). For example, in the 620 2019/2020 financial year over 50 000 aircraft arrived from regional and international destinations, and 621 while in 2020/2021 this number declined to ~13 000, by 2021/2022 the number had increased to 622 ~30 000 (Figure S2.14). Therefore, for this pathway, introduction pathway prominence is ‘moderate’ 623 throughout (Figure 2.1). There have been few qualitative changes to introduction pathway 624 prominence (Figure 2.1). Aquaculture is currently being promoted as a source of food, and, 625 consequently, aquaculture production recently increased by 35% to 10 000 tonnes. The introduction 626 pathway prominence for this pathway has increased from ‘minor’ to ‘moderate’. Introduction 627 pathway prominence was estimated for the first time for two pathways – conservation, and imports 628 of machinery and vehicles, both of which have ‘major’ introduction pathway prominence (Figure 2.1). 629 The second report highlighted research on the pet trade and medicinal plant trade, and further work 630 has been done on these two introduction pathways. New research on the pet trade has highlighted 631 the diversity of the trade (Shivambu et al. 2022a) which includes alien gastropods (Shivambu et al. 632 2020), mammals (Shivambu et al. 2021), reptiles (Mantintsilili et al. 2022), and birds (Shivambu et al. 633 2022b). Furthermore, both brick and mortar and online pet shops continue to play an important role 634 in the trade, which is mostly concentrated in highly populated areas of the country with relatively 635 large economies, such as Gauteng, KwaZulu-Natal, and the Western Cape (Shivambu et al. 2021, 636 2022b, Mantintsilili et al. 2022). The information from these recent studies confirmed that the pet 637 trade has a ‘moderate’ introduction pathway prominence. A consolidated list of 475 alien plant taxa 638 used as traditional medicine in South Africa has recently been published (Williams et al. 2021b). 639 Although some of these plants are harvested in South Africa (see section 2.3), plants are also imported 640 12 into the country, often from the home countries of traders (Williams et al. 2021a, 2022). These 641 imported plants enter South Africa through air, road, and sea transport, with most plants traded by 642 African traders arriving through the land border posts shared with Zimbabwe and Mozambique 643 (Williams et al. 2022). This research has confirmed that the medicinal plant trade is an important 644 pathway, with a ‘moderate’ introduction pathway prominence. 645 New research on wildlife ranches has highlighted the opportunities for introduction that these ranches 646 create. There are between 4.66 and 7.25 million herbivores living on wildlife ranches across South 647 Africa (Taylor et al. 2021). These ranches include ecotourism and trophy hunting properties, and so 648 introduction pathway prominence for the related pathways hunting and conservation is ‘major’. 649 Although these ranches create many opportunities for introductions, South Africa has a high diversity 650 of native ungulates, and so the threat this pathway poses in terms of the rate of introduction is likely 651 to be low—only two alien taxa [Kobus leche (Lechwe), including various subspecies, and Dama dama 652 (common fallow deer)] were recorded on surveyed properties. 653 2.2 Introduction rates 654 Introduction rates considers the number of alien taxa that have been introduced to South Africa 655 through the introduction pathways. Of the alien taxa for which introduction pathways are known (~47 656 % of alien taxa), most are plants introduced for ornamental purposes and/or horticulture (~30%), but 657 many plants have also been introduced for agriculture (~10%; Figure 2.1). Many alien organisms (e.g. 658 invertebrate pests) have been accidentally introduced along with imported plants, animals, or their 659 products (~15%); while shipping has facilitated many introductions (~10%), through the release of 660 ballast water by ships, through hull fouling, and when organisms hitchhike on the ship itself (Figure 661 2.1). There has been little change to these trends over the 2020–2022 period. 662 New introductions have been reported for 15 pathways. However, lags in reporting and for 663 information to feed through into this report continue to significantly affect the reported values, and 664 for 13 of these pathways (forestry, research, nursery material contaminant, parasites of animals, 665 contaminants of plants, parasites of plants, timber trade contaminant, habitat material contaminant, 666 packing material, ships (excluding ballast water and hull fouling), ballast water, and hull fouling, and 667 unaided), these new introductions were recorded before 2020. For example, the introduction of 668 Dipolydora socialis, a polychaete collected in the Knysna estuary in 2015, was reported in 2021 669 following genetic analysis that confirmed its identification (David et al. 2021). This polychaete could 670 have been introduced to South Africa though ballast water, hull fouling, or with organisms imported 671 for mariculture (David et al. 2021). In 2020, two new alien grasses were recorded in the country, 672 Agrostis capillaris and Festuca rubra (Sylvester et al. 2021). These taxa were likely introduced as seed 673 13 contaminants, when mixtures of grass seeds were sown on the Tiffindell ski slopes (Sylvester et al. 674 2021) and, therefore, there has been an increase in introduction rates for this pathway (Figure 2.1). 675 There have also been new introductions of biological control agents, with five new agents released 676 against invasive plants in 2021/2022 (see section 5.5. in chapter 5 for further details). While the rate 677 of introduction for biological control has, therefore, increased (Figure 2.1), this is a well-regulated 678 pathway, with all of these being legal introductions. Biological control aside, over the period 2020–679 2022 there was one permit issued for the import of an alien taxon that was not already known to be 680 legally present in the country (see Appendix 6). A permit was issued to import Meriones unguiculatus, 681 a type of gerbil, to be bred in quarantine facilities and used in medical research. However, it appears 682 that this taxon is already present in the pet trade (Shivambu et al. 2021), though the legality of the 683 initial import(s) is not known. It is not known if the permit has been exercised. Between 2013 and 684 2022, 31 new alien taxa were either illegally or accidentally introduced, at a rate of three introductions 685 per year (Figure 2.2). Between 2010 and 2019, an average of four new taxa were introduced per year, 686 this is much closer to the numbers of 2000–2009 than those reported in the second report (average 687 of three taxa per year), due in part to delays in the recording and reporting of new introductions (see 688 Box 2.1). 689 20 2.5 Trends in pathway indicators 817 Indicator Trend1 Confidence Desired trend Current status and trend Outlook 1. Introduction pathway prominence → Medium Not applicable 13 introduction pathways play a major role socio-economically. There have been few qualitative changes to this during the period 2020– 2022 despite temporary quantitative reductions due to Covid19 response measures. For two pathways introduction pathway prominence was estimated for the first time. While the trade and travel controls put in place to prevent the spread of Covid-19 impacted the opportunities provided by some pathways for introductions, these effects have been quantitative rather than qualitative. The decline in introduction opportunities have been short-lived and they are returning to prepandemic levels. Please note, a large introduction pathway prominence is not, in and of itself, undesirable in terms of invasions, providing effective biosecurity measures are in place. 2. Introduction rates → Low Not applicable (for regulated taxa) ↘ (for unregulated taxa) There has been little change recently, and alien taxa continue to be intentionally and accidentally introduced through a wide variety of pathways. During the 2020–2022 period, five new taxa were legally introduced for biological control, and one taxon that was already in the country was legally introduced for other purposes. Two new taxa were accidentally introduce d as seed contaminants. In many cases regulated taxa (for which the risks have been analysed and found to be acceptable) are expected to be a net benefit to the country, and in the case of biological control, assist with the control of biological invasions. Therefore, no specific trend is desirable for regulated taxa, but what is desirable is that a process is in place to regulate them (section 5.1. in Chapter 5). The rate of introduction of unregulated taxa will increase as the volume of trade and travel i ncreases. The rate of introduction of unregulated taxa is, however, sensitive to the intensiveness of survey activities and is likely to be relatively unresponsive to changes in actual introductions (Box 2.1). Unless pathways are identified, prioritised an d managed, potentially harmful alien taxa will continue to be accidentally and illegally introduced. 1→ no change; ↗ an increase; ↘ a decrease 21 Indicator Trend1 Confidence Desired trend Current status and trend Outlook 3. Withincountry pathway prominence Not assessed Not applicable Information was only obtained for a few pathways. Many pathways are likely playing a role socio-economically within the country, but the extent of this role and how it has changed recently is not known. Restrictions on within-country trade and travel to prevent the spread of Covid-19 had a short-term impact on the withincountry dispersal opportunities provided by some pathways. There is no desired trend for withincountry pathway prominence as it is a function of internal trade and transport. However, trends in these pathways need to be tracked to ensure interventions are in place where they are needed. If this is not done harmful taxa will continue to spread, native taxa will be introduced and possibly cause impacts in parts of the country where they are not native, and valuable assets will be put at risk. 4. Withincountry dispersal rates Not assessed Not applicable (for regulated taxa) ↘ (for unregulated taxa) National-scale data have yet to be collated for alien taxa, but information has become available for native-alien populations. Most nativealien populations are plants introduced for horticulture, or mammals for aesthetics. But native-alien populations are also the result of accidental introductions, for example, organisms moved with transported plants or plant products, or that disperse through inter-basin water transfer schemes. Increases in the volume of trade and travel will lead to increases in the within-country dispersal rates of taxa known to be invasive, or that are considered likely to become invasive. Unless pathways that facilitate the within-country dispersal of taxa are identified, prioritised, and managed, the spread of these taxa will increase, and so there will be increases in both the rate of expansion of currently invasive taxa, and in the likelihood that alien taxa will find a suitable part of the country in which to become invasive. High level indicator A. Rate of unregulated introduction of new species → Low ↘ Over the last decade (2013–2022) approximately 3 new taxa were introduced per year either accidentally or intentionally, but illegally. This is similar to previous estimates. Opportunities for the introduction of alien taxa are expected to increase as the volume of trade and travel increases. Whether this results in the introduction of more invasive taxa will depend on the degree to which key pathways are identified and prioritised for management. Improvements to inspection, management, and incursion response at-border would strengthen South Africa’s biosecurity. See chapter 5 for details on some positive developments on this front. 818 22 Chapter 3: Species 819 Lead authors: Tsungai A. Zengeya; John R. Wilson 820 Contributing authors: Whitney Engelbrecht; Katelyn T. Faulkner; Laura M. Fernandez Winzer; Sabrina 821 Kumschick; Emily J. McCulloch-Jones; Siyasanga Miza; Aviwe Sifuba 822 Key findings1 823 to be added 824 Key gaps 825 • Data on the distribution and abundance of alien species need to be collected, collated, and 826 integrated into national and global databases to facilitate the planning of interventions. 827 • The systematic quantification of the impacts of biological invasions would: facilitate the 828 prioritisation of interventions targeting particular species and particular sites; provide the 829 justification for government investment to control biological invasions; and provide important 830 background to communicate the issue to society. 831 Indicators covered in this chapter 832 833 834 1the key findings will be added after the analysis is finalised. The gaps listed presented are the same as in 2019, but the situation has not changed 5. Number and status of alien species 6. Extent of alien species 7. Abundance of alien species SPECIES 8. Impact of alien species HIGH LEVEL B. Number of invasive species that have major impacts 23 3.1 Number and status of alien species 835 A major part of this report cycle was to ensure that the species list used was transparent and all 836 records are traceable. This process is on-going. In particular new species from additional key sources 837 will be added (Table 3.1; see supplementary material S3.2 for further details). Some progress has been 838 made, but a large part of the work still needs to be done and it is anticipated that it should be 839 completed for the second draft that goes out or public comment. All the revisions to the species list 840 (Appendix 2) will be incorporated in the analyses in the second round of public review. Readers are 841 kindly requested to interrogate the species list and provide detailed feedback; please also evaluate 842 the data sources that are to be incorporated and provide details of additional sources that should be 843 included. 844 Table 3.1. List of key sources that will be used to update the checklist of alien species that are known 845 to occur in South Africa as of December 2022. 846 Taxa or database Reference Species list from 2nd report http://dx.doi.org/10.5281/zenodo.3947659 Barcode of Life www.boldsystems.org Horticultural plants Hoy et al. 2021 Marine taxa Robinson et al. 2016; 2020; Hodgson et al. 2021, Bezuidenhout and Robinson 2020, Rodewald et al. 2021; Ma et al 2021; Singh et al. 2021; Zeeman et al. 2020; Makherana et al. 2022 Cultivated plants Glen 2003 Tree species in arboreta Cheek at al. 2022 Species in the pet trade Nelufule et al. 2020; Shivambu et al. 2020; Shivambu et al. 2021a,b; Mantintsilili et al. 2022; Niemann et al. 2022; Shivambu et al. 2022a,b Species in zoological gardens SANBI Alien species in the medicinal plant trade Williams et al. 2021a,b; Williams et al. 2022 Alien ferns McCulloch-Jones et al. 2021 Insects of cultivated plants and natural pastures Prinsloo & Uys, 2015 Interception data at ports of entry Saccaggi et al. 2021 Taxa for which permits have been issued under the NEM:BA A&IS Regulations Appendix 6 Citizen science iNaturalist Biocontrol agents of alien plants Centre for Biological Control Herbarium records and other species databases that may contain information on alien taxa BODATSA Alien bamboo species Canavan et al. 2021 Alien invertebrates Charlene Janion-Scheepers, University of Cape Town Biocontrol agents of agricultural pests Prinsloo & Uys 2015; Pretorius 2008 Encyclopaedia of biological invasions in South Africa van Wilgen et al. 2020 847 24 An interim analysis is presented in Figure 3.1, noting as has been remarked elsewhere that South Africa 848 is a particular hotspot for plant invasions and relatively (both to plant and to other regions) less 849 affected by animal invasions. 850 851 Figure 3.1 The number of alien species per kingdom recorded as present in South Africa as of 852 December 2022 (see Appendix 2). Many of these taxa are not invasive, and some are only known from 853 captivity or cultivation. The list is not comprehensive (many alien taxa in captivity or cultivation are 854 not included yet). However, for each taxon present here the evidence for their presence is clearly 855 specified in Appendix 2 and the names are valid according to the latest taxonomic sources. Given this 856 is a revised process, it is not yet possible to compare values with the previous report. 857 3.2 Extent of alien species 858 3.2.1 Number of broad-scale regions occupied per species 859 Table 3.2. The number of alien species that are recorded as present in a given number of provinces in 860 South Africa as of December 2022 based on occurrence records from GBIF and the change in these 861 values since December 2019. 862 Period Number of provinces 1 2 3 4 5 6 7 8 9 End of 2019 281 161 140 82 80 63 70 59 87 End of 2022 To be completed, both to see if the numbers have changed and if broad distribution patterns have changed 3.2.2 Number of quarter-degree grid cells occupied per species 863 25 To be added. Once the species list is finalised, Figure 3.1 will be updated based on GBIF data and 864 historical data, enabling an analysis of whether broad distribution patterns have changed; cases where 865 species range have notably expanded; and how different data sources provide additional information, 866 e.g., iNaturalist. Notably during this period the southern African Plant Invaders Atlas (SAPIA) was put 867 on a hiatus in the first quarter of 2020, this was a major project that provided standardised data on 868 the distribution of alien plants, notably the use of citizen science data cannot replace such active 869 surveillance efforts. 870 871 Figure 3.1. The increase in the recorded extent of selected alien species as presented in the previous 872 report. The figure will be updated for the period 2020–2022 and included as part of the next draft. 873 3.3 Abundance of alien species 874 In previous reports, estimates of the abundance of alien species were based on two sources of data 875 on terrestrial plants—a 1998 report to the Water Research Commission (Versfeld et al. 1998) and the 876 National Invasive Alien Plant Survey (Kotzé et al. 2010). This situation has not changed. There have 877 been some recent developments, for example, the National Invasive Alien Plant Survey approach was 878 recently further described (Kotzé et al. 2019) and applied at a small scale in the Agulhas Plain in South 879 Africa (Kotzé et al. 2020). 880 3.4 Impact of alien species 881 A recent review of the impacts of biological invasions in South Africa confirmed previous assertions 882 that, although it is clear that a significant number of species cause major negative impacts, there are 883 26 few studies that formally document the impacts of alien species on biodiversity (see supplementary 884 material S3.5; van Wilgen et al. 2022). There is an increasing effort to assess the impacts of alien 885 species using standardised protocols, but in the few cases where assessments have been done, there 886 is generally a lack of information (Zengeya et al. 2020; van Wilgen et al. 2022). In 2019, national-level 887 EICAT assessments had been completed for 32 species, this has increased slightly to 49 species in 2022 888 (see supplementary material S3.5). In addition, the number of species assessed as having major or 889 massive impacts increased from seven species in 2019 to 18 in 2022. These include tree species such 890 as the red gum (Eucalyptus camaldulensis) that forms dense thickets along waterways and dominates 891 or excludes native vegetation (Tererai et al. 2013, Hirsch et al. 2019); two Prosopis species that 892 competitively displace native vegetation (Schachtschneider and February 2013), birds (Dean et al. 893 2002), and invertebrate communities (Steenkamp and Chown 1996); five Acacia species that cause 894 major impacts on native species through competition and changes to ecosystem functioning (Jasen 895 and Kumschick 2022); as well as Lantana (Lantana camara) and Triffid weed (Chromolaena odorata) 896 that cause physical changes to ecosystem structure leading to a decline in, and local extirpation of, 897 some invertebrate species (Samways et al. 1996, Mgobozi et al. 2008). In terms of animals, the 898 Argentine ant (Linepithema humile) competitively displaces and reduces the abundance of native ants 899 (Schoeman and Samways 2011). 900 In 2019, there was a limited number of national-level SEICAT assessments done in South Africa and 901 this had not changed by 2022, with only a few additional assessments done on Acacia species (see 902 supplementary material S3.5). Alien species can cause both positive and negative environmental 903 impacts (Vimercati et al. 2020). A major advance since 2019 in monitoring the impact of alien species 904 has been the development of the EICAT+ framework (Vimercati et al. 2022) that enables the 905 classification of positive impacts of alien taxa on native biodiversity. 906 Box 3.1 Native-alien populations 907 Species that are native to South Africa have been intentionally and accidentally moved around the 908 country and introduced to parts of the country where they are not native (see Chapter 2 for details on 909 their pathways of dispersal). There are various working definitions for this phenomenon, and a variety 910 of terms have been in use, including ‘extralimital introductions’ (Ellender and Weyl 2014) and 911 ‘domestic exotics’ (Measey et al. 2017). But, recently Nelufule et al. (2022) proposed that the 912 phenomenon be defined as a “population that is: (1) within a country to which the species is native, 913 (2) founded by individuals moved by direct human agency [or substantial indirect human agency, see 914 Essl et al. (2018)], (3) over a biogeographical barrier and (4) to an area beyond the species’ native 915 range”. The term ‘native-alien populations’ has been proposed (Nelufule et al. 2022), and a protocol 916 27 for classifying these populations has been developed based on the proposed definition (Nelufule et al. 917 in prep-a). This means that there is now a process both to circumscribe the phenomenon and confirm 918 instances. Native-alien populations are understudied globally, but they deserve more attention (Vitule 919 et al. 2019). This is because although these populations are a subset of alien populations, they tend to 920 differ from other alien populations in terms of their invasion potential and the type of impact they 921 have, as they pose a specific management and regulatory challenge, and as their prevalence will likely 922 increase with global change (Nelufule et al. 2022). 923 In an effort to fill data gaps, an inventory of native-alien populations in South Africa has been 924 developed (Nelufule et al. in prep-b). The inventory contains information on 77 native species from 925 nine classes that have formed 132 native-alien populations across the terrestrial (101 populations), 926 freshwater (26 populations), and marine environments (5 populations). Most of these populations are 927 established (59%), but a few are invasive (18%). Some of these native-alien populations have had dire 928 impacts in South Africa (Box Figure 3.1). Although the phenomenon appears to be rare in comparison 929 to the number of alien species introductions from other countries (section 3.1), it is under-reported. 930 As the inventory follows, where possible, global data standards it can be easily integrated into the 931 species list of this report, thus making it possible to report on the status of these populations in future 932 reports. 933 934 Box Figure 3.1 Examples of taxa with native-alien populations in South Africa that have threatened 935 native biodiversity through hybridisation: A) populations of Orange River mudfish (Labeo capensis) 936 translocated to the Eastern Cape have hybridised with moggel (L. umbratus), leading to introgression 937 and threatening moggel’s genetic integrity (Ramoejane et al. 2020); and B) blesbok (Damaliscus 938 pygargus subsp. phillipsi) native-alien populations in the Western Cape hybridised with the endemic 939 bontebok (D. pygargus subsp. pygargus), and only through concerted and intensive interventions was 940 the extinction of bontebok prevented (van Wyk et al. 2017). 941 28 3.5 Trend in species indicators 942 Indicator Trend1 Confidence Desired trend Current status and trend Outlook 5. Number and status of alien species Not reassessed yet ↘ (for invasive species) This report contains details of XXX alien species that were known to occur in South Africa. Over XXX % of these were regarded as invasive. The process of documenting and tracking changes in the status of alien species has been substantially improved through the development of workflows to ensure that work is properly documented and repeatable. South Africa faces a substantial invasion debt because most alien species are not yet invasive, and new alien species will continue to arrive. The number of alien species recorded in the country will also increase if more effort is spent on detection, even for well-studied groups like plants. The updated alien species list contained in this report represents a step towards a national registry of alien species in the country. It captures the current state of knowledge of the status of each alien species in a manner that allows for the information to be easily reviewed and updated. This promises to provide the foundational biodiversity information that is essenti al for management and policymakers. 6. Extent of alien species Not reassessed yet ↘ Not reassessed yet In 2019, the majority of alien species were localised and only a few were widespread. However, the potential for them to increase their distribution is large and the extent of most species will continue to increase unless effective control is put in place. 7. Abundance of alien species Not assessed ↘ No new data were available on the abundance of alien species Understanding trends in abundance is important if the effectiveness of management interventions are to be monitored, and the magnitude of future impacts predicted. 8. Impact of alien species ↗ Medium ↘ 17 species have been assessed using an evidence-based framework since 2019. 11 species have been reported to cause major to massive impacts using EICAT and 5 using SEICAT. However, there was no reliable data for the majority of the assessed species. This remains a major gap where detailed research is needed. Unless the impacts of invasive species can be quantified, attempts to regulate them will remain contentious in many cases. 1→ no change; ↗ an increase; ↘ a decrease 29 Indicator Trend1 Confidence Desired trend Current status and trend Outlook High-level indicator B. Number of invasives that have major impacts ↗ ↘ In 2019, 32 species had national-level EICAT assessments, this has slightly increased to 49 species in 2022. The number of species that were assessed as having major or massive impacts increased from seven species in 2019 to 18 species in 2020 (five fish, two grasses, 10 trees, and one mammal species, one ant species). However, in many cases, there was a lack of reliable data. That is the number of alien species recorded to have major or massive negative impacts will increase as more species are formally assessed. The formal assessment of the impact of alien species provides the rationale for regulation and management, can improve compliance and implementation of intervention measures, and assist to resolve conflicts. However, impact assessments are hampered by a lack of reliable data for most species. If this situation persists, regulations will continue to be vulnerable to legal challenges. It is very difficult to control invasive species with major impacts in a way that will reduce such impacts to moderate or minor, but this has arguably been achieved by biological control for over 30 invasive taxa. On-going investment in biological control will likely result in more such successes. If alien species that currently have moderate or minor impacts are prevented from increasing in abundance and extent to the point where they have major impacts or, where feasible, such species are eradicated from South Africa, then significant returns on investment may also be made. 943 36 Box 4.1 Estimating the costs of invasions (damage and intervention)—InvaCost 1034 Biological invasions affect ecosystem functioning and hinder the delivery of ecosystem services, often 1035 leading to significant economic losses (Vaissière et al. 2022). Historically, the costs that biological 1036 invasions cause in damages and the costs spent trying to mitigate or prevent invasions have rarely 1037 been estimated in detail, and where estimates have been made, they are generally fraught with major 1038 assumptions (Cuthbert et al. 2020) and cannot easily be compared or tallied at national or global scales 1039 (Latombe et al. 2017; Diagne et al. 2020a). In an attempt to address this, Diagne et al. (2020b) 1040 developed a global-scale data repository of the reported economic costs associated with biological 1041 invasions (dubbed InvaCost). Costs are adjusted for inflation and categorised by various descriptors 1042 including whether they are observed or predicted; whether the method use has a high or low 1043 reliability; and whether the costs are for management or damage. 1044 InvaCost studies have been completed for a range of topics (for the latest list see 1045 https://invacost.fr/en/outcomes/), but not as yet for South Africa. Initial work from South Africa using 1046 observed, highly reliable cost entries, has placed the estimate at USD6.6 billion (all costs adjusted to 1047 2017 USD values). These costs are due to 42 (mostly plant) taxa. This total comprised a relatively even 1048 division between damage (USD3.22 billion) and management (USD3.44 billion), a finding very different 1049 to other existing national synthesis which show a clear dominance in damage costs (Zenni et al. 2021). 1050 There was almost no recorded spending pre-invasion management in the country; instead the 1051 majority of costs (USD3.28 billion) were for post-invasion management; with relatively small but still 1052 significant spending on communication and research (~USD15 million) and on other ancillary costs 1053 (USD 51.4 million). 1054 These figures are considerably higher than those estimated by van Wilgen et al. 2022, the reasons 1055 remain to be explored. There remain many cost-data gaps for the country, specifically as presented 1056 by the severe lack of cost information for various taxonomic groups and species. These costs are thus 1057 an incomplete reflection of the impacts and related cost of invasions in South Africa. There is a need 1058 to relate environmental impact studies to economic values as a means to better inform interventions 1059 and policy development. 1060 37 4.4 Trends in sites indicators 1061 Indicator Trend (confidence) 1 Desired trend Current status Outlook 9. Alien species richness Not reassessed yet ↘ (for invasive species) Not reassessed yet The development of a robust and reliable monitoring methodology should be seen as a priority, because in the absence of reliable information on species richness and relative abundance, neither the magnitude of impacts nor the effectiveness of management can be properly assessed. 10. Relative invasive abundance Not assessed ↘ There are no country-wide estimates for the relative abundance of invasive species, but estimates for invasive plants in protected areas managed by Cape Nature and SANParks invasions are minor to moderate. Achieving consistency in tracking relative abundance in protected areas could be facilitated by the inclusion of a standardised monitoring protocol in the criteria for the preparation of management plans which were developed by the DFFE in terms of the A&IS Regulations. It is expected that existing invasions will densify unless managed. The costs of control and the impacts caused often increase dramatically with the level of invasion. 11. Impacts of invasions Not reassessed yet ↘ Not reassessed yet Impacts are likely to increase as invasive species continue to spread, and as control efforts are scaled back in response to fiscal constraints. This underscores the importance of refocussing control efforts on agreed priority sites, and taking steps to improve control effectiveness. High level indicator C. Extent of areas that suffer major impacts from invasions Not reassessed yet ↘ If control efforts focus on priority sites (e.g. sites that provide water to Cape Town’s dams) then there will be significant returns on investment. However, without agreement on priorities, there is a substantial risk that control could remain ineffective, and the area that suffers from major impacts will continue to grow. Estimates of the full magnitude of impacts re quire more accurate assessments of the extent of invasions. This, in turn, requires effective mapping of the areas invaded and monitoring of spread. Such monitoring is currently lacking, and without which effective prioritisation is not possible. 1062 1→ no change; ↗ an increase; ↘ a decrease 38 Chapter 5: Interventions 1063 Lead authors: Brian W. van Wilgen; Katelyn T. Faulkner; John R. Wilson; Márthan Theart 1064 Contributing authors: Nicholas Cole; Julie A. Coetzee; Leoni Pretorius; Roger Price; Louise Stafford, 1065 Andrew A. Turner; Karabo Wanjau; Andrew Wannenburgh; Costas Zachariades 1066 Key findings 1067 • The NEM:BA A&IS Regulations and Lists were revised and promulgated in 2020. These 1068 amendments are considered to have improved the regulatory regime. 1069 • At least R 1.4 billion has been spent on the management of biological invasions over the period 1070 2020–2022. However, the money spent has declined steadily in real terms since 2015. 1071 • A lack of adequate planning remains a constraint to effective management, and a lack of 1072 monitoring means it is hard to evaluate the effectiveness of management that is in place. 1073 • Plans are assumed to exist for the management of 40 of 44 identified introduction pathways, 1074 although no formal plans have been approved by DFFE. The management of seven pathways 1075 is effective and of one pathway is partially effective. For the remainder, the effectiveness of 1076 management is either unknown (14 pathways), ineffective (17 pathways), or there is no 1077 management (five pathways). 1078 • Few regulated species have management plans in place. 1079 • 196 out of the 559 regulated taxa have received some form of active treatment (e.g., clearing) 1080 over the past three years. However, the effectiveness of control is unknown for most (130) of 1081 the treated species. Twelve species were assessed as being under permanent control (based 1082 on an assessment of complete biological control). Of the remainder, control was effective (16 1083 species), partially effective (13 species) or ineffective (11 species). For 14 species that are 1084 targets for national eradication, the effectiveness of management still has to be evaluated. 39 1085 alien pests of agricultural crops were subjected to biological control, but only one of these 1086 pests is listed under the NEM:BA A&IS Regulations. 1087 • Only ~15% of the estimated invaded area in South Africa is covered by site management plans; 1088 many of these plans do not meet the required standards. Control operations reached 1% of 1089 the estimated invaded area between 2020 and 2022. There is evidence that control efforts 1090 have reduced the area invaded at some sites, but most invasive species have continued to 1091 expand their range when assessed at a national scale. 1092 • The Working for Water programme’s performance is measured in terms of employment 1093 created and money spent (inputs), and area cleared (an output), but not in terms of outcomes 1094 39 (changes in the extent of invasions; restoration of ecosystem function). It therefore plans to 1095 spend money, employ people and clear sites, but not explicitly to achieve control. This lack of 1096 monitoring of the outcomes of control measures, along with the absence of management 1097 plans with clear goals, remains a substantial impediment to assessing the effectiveness of 1098 control measures. 1099 Key gaps 1100 • Interventions on biological invasions in South Africa are not strategically focussed in the 1101 absence of a comprehensive policy and strategy. 1102 • The effectiveness of interventions cannot be routinely demonstrated, control measures 1103 cannot be compared and improved, and it is not clear whether progress is being made to 1104 reduce the negative impacts of invasions. Formal programmes to monitor the effectiveness of 1105 interventions would assist with all of these. 1106 Indicators covered in this chapter 1107 1108 1109 INTERVENTIONS 12. Quality of regulatory framework 13. Money spent 14. Planning coverage HIGH LEVEL D. Level of success in managing invasions INPUTS 15. Pathways treated 16. Species treated 17. Sites treated OUTPUTS 18. Effectiveness of pathway treatments 19. Effectiveness of species treatments 20. Effectiveness of site treatments OUTCOMES 40 5.1 Input—quality of the regulation framework 1110 Between January 2020 and December 2022, the primary legislation governing biological invasions in 1111 South Africa (the NEM:BA of 2004) has not changed1, though the associated regulations have (see 1112 supplementary material S5.1 for the full details). Revised NEM:BA A&IS regulations and lists were 1113 published in September 2020. The revised regulations and lists came into force on 1 March 2021, but 1114 the inclusion of two trout species, Oncorhynchus mykiss and Salmo trutta, in the lists has been 1115 suspended until further notice. 1116 The main changes were: 1117 ● Provision for “Category 1b Control Plans” (includes taxa in other categories that are beyond 1118 permitted or exempt areas); 1119 ● Ports of entry for import are specified; 1120 ● A general obligation is specified requiring efforts to prevent spread and control any escapes 1121 of listed invasive species; 1122 ● The removal of the prohibited list; 1123 ● Applications for permits for listed invasive species need to include information specified in the 1124 “Risk assessment framework” (previously this was only specified for import permits); 1125 ● Risk assessment practitioners (previously facilitators) do not need to be independent, and 1126 whether a risk assessment is required is determined by the issuing authority; 1127 ● The issuing authority must notify potentially affected municipalities (not just provinces) of an 1128 application for a permit; 1129 ● Where other regulatory processes also govern the restricted activities, and the issuing 1130 authority is also the decision-maker in terms of the other regulatory processes, the applicable 1131 decision-making timeframes must be aligned; 1132 ● Permits may only be issued for a period not exceeding ten years (previously five) under 1133 circumscribed circumstances; 1134 ● If listed invasive species are present on land that is sold, permits may be transferred to the 1135 new owner providing the new owner contacts the department (previously, the seller was 1136 obligated to notify the buyer of the presence of alien and invasive species on the land and the 1137 buyer had to apply for a permits), this does not apply to the sale of listed invasive species; and 1138 ● The heading “Prohibited alien and listed invasive species directives” was removed. The 1139 obligation to keep a record of directives has been retained, but moved to another regulation. 1140 There were no changes to the annexures. 1141 1it is likely that the National Environmental Management Laws Amendment Act, 2022 will be brought into effect in 2023 41 The decision to remove the prohibited list1 was on the basis that: a) all alien taxa not legally present 1142 in South Africa require an import permit regardless of whether they are listed as prohibited; and b) 1143 the evidence as to why taxa were included on the prohibited list was not available. This does not affect 1144 the activities that are prohibited with regard to other listed taxa. 1145 Other than the prohibited list there were changes to the listings of ~82 taxa between 2018 and 2020. 1146 The majority of listings (>85%) stayed the same2. 1147 Requests to change the listings of taxa under the NEM:BA A&IS regulations have, to date, been dealt 1148 with on an ad hoc basis (see supplementary material S5.3). A standardised official process for 1149 publishing proposals to revise the regulatory lists is under development. To support this, risk analyses 1150 are produced in a consistent format using a risk analysis framework developed specifically for South 1151 Africa (Kumschick et al. 2020a). These risk analyses are reviewed by an independent scientific panel 1152 [the Alien Species Risk Analysis Review Panel (ASRARP); see Kumschick et al. (2020a) for more details] 1153 set up and run by SANBI on DFFE’s behalf. 1154 Sixty-seven risk analyses were reviewed by the ASRARP and submitted by SANBI to DFFE between 1155 January 2020 and the end of November 2022 (see supplementary material S5.5). Ten of these taxa 1156 were not listed, of the remaining 57, the listing for 33 taxa was suggested to remain as is (changes to 1157 nomenclature excepted). However, the risk analyses themselves are not yet, in the public domain, 1158 and the framework is not yet, an official government document. 1159 Terms of reference for a governmental decision-making body [The Risk Analysis Review Committee 1160 (RARC)] have been circulated and the body is due to have its inaugural meeting in February 2023. The 1161 RARC, amongst other functions, intends to review proposals to change listings received by SANBI 1162 (based on ASRARP’s recommendations). This process would facilitate regular revisions to the lists as 1163 new information becomes available, as new requests are made, and as nomenclature changes3. 1164 In terms of permits4, in 2020 five import permits were issued by DFFE on four taxa [Bitis nasicornis 1165 (Shaw, 1802), Dendrobates tinctorius (Schneider, 1799), Nasturtium officinale R.Br., Pennisetum 1166 purpureum Schumach.5]; by comparison 76 import permits were issued on 14 taxa in the period 2015–1167 1a list of taxa that were not legally in the country and that may not be imported 2this analysis is still to be finalised; it will be presented in S5.2 in the next draft. 3notably, the nomenclature in the regulatory lists does not currently match that of appropriate taxonomic backbones for a significant number of listed taxa, with several synonyms included, and two taxa are listed that are not valid (see supplementary material S5.4). 4this analysis is only based on data up to the end of 2020 (see Appendix 6). The permit data will be reanalysed using data collected up to the end of 2022 in the next draft. 5The names presented here are as they were on the permits (see Appendix 6), see supplementary material S5.4 for a table converting these names to those in the species list (via the use of a taxonomic backbone). 42 2019 (no permits were issued in 2014). During 2020, 216 permits were issued for category 2 species. 1168 This was also fewer that the number issued in the previous years (an average of ~350 per year for 1169 2015–2019). Notably, 37 of the 117 category 2 listed taxa have had no permits issued for their usage, 1170 a further 37 taxa have had five or fewer permits issued, but the five most frequently permitted taxa 1171 have had over 200 permits each (Kobus leche subsp. leche; Ctenopharyngodon idella including triploid 1172 grass carp; alien Oreochromis species; Psittacula krameri; and Dama dama) (see supplementary 1173 material S5.6; for the full list of permits see Appendix 6). 43 permits were issued for research, display, 1174 or biocontrol purposes in 2020 (compared to an average of 17 per year previously). This included an 1175 import permit for Meriones unguiculatus (Milne-Edwards, 1867) for use in medical research as a model 1176 organism. One explanation of these trends is that fewer permits were issued for category 2 taxa due 1177 to the lockdown reducing internal trade, but the greater number of research permits issued reflects a 1178 greater awareness and subsequent compliance with the regulations (the lack of research permits 1179 relative to the expected need was noted as a concern in previous reports). 1180 There were no successful prosecutions under the NEM:BA A&IS regulations in the period covered by 1181 this report. Two cases went to court but were dismissed. In the first case, the state failed to prove 1182 intention (for the transport of red-eared sliders, Trachemys scripta). The second case involved a pet 1183 shop that had applied for a permit to trade in Category 2 listed species, and then sold them before a 1184 permit was issued. The court ruled that the DFFE had taken an excessively long time to issue the 1185 permit, thus unreasonably preventing the trader from conducting business, and the case was 1186 dismissed. 1187 The National Environmental Laws Amendment Act, 2022 (NEMLAA) was assented by the President in 1188 June 2022 although as of 20 December 2022 it has not been promulgated. The Amendment Act 1189 amended, among other Acts, NEM:BA. Once NEMLAA commences, NEM:BA will have clearer 1190 definitions of the terms “eradicate” and “control”. It will also be clearer from the text that invasive 1191 species must be either eradicated or controlled depending on what is possible under the 1192 circumstances, whereas presently, landowners and other role-players are required to both eradicate 1193 and control invasive species. Furthermore, NEM:BA will no longer require landowners to notify 1194 competent authorities of the presence of invasive species on their land. The Minister will have the 1195 power to specify the circumstances under which such notification must be given to the competent 1196 authority. 1197 A national strategy for biological invasions is under development, led by the DFFE with input from 1198 other departmental officials and scientists from SANBI. As of 1 December 2022, the draft strategy is 1199 yet to be made available for public comment. 1200 43 Finally, a “Draft White Paper on the Conservation and Sustainable Use of South Africa’s Biodiversity” 1201 was published for public comment in August–September 2022. Biological invasions were referred to 1202 in one policy objective: “Prevent the introduction, establishment, and spread of potentially harmful 1203 alien species, and control and eradicate, where feasible, invasive species which threaten ecosystems, 1204 habitats and species.” This draft policy objective and the expected outputs and outcomes are not 1205 currently aligned with the draft CBD goals nor the developing national strategy, e.g., the focus was 1206 simply on species, rather than on pathways, species, and sites (cf. Essl et al. 2020). The proposed white 1207 paper will represent an important step, but it is unclear if it would negate the need for a policy 1208 specifically on biological invasions as arguably the scope of the White Paper does not fully overlap 1209 with the scope of concerns raised by biological invasions. Lukey and Hall (2020) make it clear that law 1210 can be used to implement policy. If a law does not make provision for a means to implement policy, it 1211 may be necessary to introduce new laws or regulations. A White Paper is a pre-cursor to law, but there 1212 is still no policy on biological invasions, so it is not immediately clear what has informed the drafting 1213 of references to invasions in the White Paper. 1214 At an international level, South Africa is party to the Convention on Biological Diversity (CBD). The 1215 CBD set a series of international goals for 2020 (including the Aichi Biodiversity Targets, with target 9 1216 explicitly on biological invasions). While the scientific community has discussed what a revised target 1217 on biological invasions should contain (e.g., Essl et al. 2020), a revised target is still to be agreed on at 1218 a political level1. 1219 An analysis of enforcement activities, and specifically the use of notifications, directives, prosecutions, 1220 and convictions will be provided in supplementary material in the next draft (see supplementary 1221 material S5.2). 1222 5.2 Input—money spent 1223 In total, 14 organisations reported on money spent on biological invasions for 2020–2022, amounting 1224 to ~R1.4 billion (Table 5.1). 1225 A retrospective analysis of the available information on spending by the DFFE’s Working for Water 1226 programme (WfW) between 1999 and 2020 (van Wilgen et al., 2022) considered five categories of 1227 spending: 1) efforts to control established invasive species; 2) an incursion response program that 1228 assessed and controlled alien plant taxa that were either not listed or that were eradication targets; 1229 3) value-added projects; 4) high-altitude sites; and 5) biological control research and implementation. 1230 1a revised target is being discussed at the COP15 Meeting in Montréal, Canada, 7–19 December 2022, the outcome will be included in the next order draft. 44 The total amount spent on interventions by the WfW program between 1999 and 2020 amounted to 1231 ZAR 7.1 billion, adjusted to 2020 values of ZAR. The bulk of this (ZAR 5.27 billion) was spent on the 1232 control of species that were well-established. Annual amounts spent on contract teams rose steeply 1233 between 2000 and 2003, and then stabilised until 2010. Further increases followed, peaking in 2015, 1234 and declined steadily thereafter (see supplementary material S5.7). Some of the relative decline in 1235 amount spent on control projects after 2015 was due to funding being diverted to value-added 1236 projects. Between 2015 and 2020, available information shows that an average of ZAR 62.7 million 1237 was spent on biological control research and implementation per year (2020 ZAR values). Of this, 87% 1238 was spent on locating, screening, releasing, and monitoring new biological control agents, and 13% on 1239 mass-rearing and release programs for established agents. 1240 Another estimate of the money spent was from the InvaCost database, which is based on consolidated 1241 information from various sources (see Box 4.1)1. For South Africa, there was no record of funding for 1242 pre-invasion management. Post-invasion management costs amounted to 3 667 860 483 USD (~ZAR 1243 62.3 billion). Knowledge funding in South Africa amounted to USD 14 964 839 (~ZAR 253 million). 1244 Mixed funding added a further USD 51 431 269 (~ZAR 873 million). All values in the InvaCost database 1245 are expressed in 2017 values of USD. These figures are known to be underestimates, but seem to be 1246 considerably higher than those estimated by van Wilgen et al. (2022). 1247 Jubase et al. (2021) surveyed the contributions made by volunteer hack groups in the Western Cape 1248 province. They broadly estimated that half of these groups cleared nearly 5300 ha of land per year 1249 with estimated labour contributions of ZAR 5.1 million when aligned with formal state management 1250 cost estimates. 1251 Maluleke et al. (2021) retrospectively estimated the relative herbicide cost-saving associated with the 1252 use of biological control instead of chemical control. The study used a cost benefit analysis framework 1253 with an 8% discount rate. The estimated cost-effectiveness of the biological control on four invasive 1254 alien aquatic plant species (Azolla filiculoides, Myriophyllum aquaticum, Pistia stratiotes, and Salvinia 1255 molesta, in order of cost-effectiveness), which are under complete biological control in South Africa, 1256 was about ZAR 7.8 million, while the estimated cost of chemical control to achieve the same level of 1257 control varied between ZAR 150 million and ZAR 1 billion, depending on the method of application 1258 and number of follow up operations. 1259 1260 1an analysis of InvaCOST specifically for South Africa is underway and these numbers will be revised based on that analysis, this updated information will be included in the final report. 45 Table 5.1 Money reported as having been spent on the management of biological invasions in South Africa by different organisations between 2020 and 1261 2022. The amounts are totalled for three years, unadjusted for inflation. Inputs are still to be received from various organisations and many stakeholders, 1262 particularly in the private sector, have not been included (and so the overall figure should be viewed as a lower estimate). However, it is also possible that 1263 there may be some double counting, as some of the money spent by implementing agencies may also have been reported by the DFFE’s Working for Water 1264 Programme, this is to be addressed in the final report. 1265 Organisation Money spent on Money spent Notes Agricultural Research Council Biological control research 104 495 930 ZAR 69 700 073 from the DFFE and ZAR 34 795 857 from the ARC. Buffalo City (East London) Protected areas within the municipal boundaries 9 151 000 This includes other activities such as clearing of vegetation along road verges Cape Nature 31 protected areas in the Western Cape Province 9 299 189 Most of this money came from Working for Water and so there may be some double counting Centre for Biological Control, Rhodes University Biological control research and implementation 82 000 000 ZAR 59 million from Working for Water; ZAR 15 million from the DST-NRF via the South African Research Chairs Initiative; ZAR 8 million from other sources. The bulk is spent at Rhodes University, but part of the funding is distributed to the Universities of Cape Town, Witwatersrand, KwaZulu/Natal, Mpumalanga, and Fort Hare City of Ekurhuleni (Gauteng) Management of aquatic ecosystems 17 700 000 Funding has been expended mostly on water hyacinth (Pontederia crassipes), giant reed (Arundo donax), and yellow water lily (Nymphaea mexicana) invading aquatic ecosystems Department of Agriculture, Land Reform and Rural Development Responsible for Conservation of Agricultural Resources Act (CARA) and other legislation. Maintains a presence at all border posts. waiting for inputs DFFE animal control projects Control of invasive animals waiting for inputs DFFE Biosecurity Monitoring activities aimed at interception of alien species at OR Tambo International Airport waiting for inputs some inputs received awaiting full values DFFE high altitude teams Specially trained teams deployed to control invasive alien plants in relatively inaccessible or mountainous terrain 255 298 699 Budgeted amount for financial years. The DFFE reported an amount of ZAR 208 237 112, and 22.6% was added to account for overheads (van Wilgen et al., 2022) 52 were imported for biological control programmes on 52 pest species on crops such as citrus, wheat, 1362 forestry, fruit, and vegetables between 1892 and 2008. Of these 142 were released and 49 became 1363 established (see Appendix 2). These biological control agents are used against 39 alien agricultural pest 1364 species, only one of which is listed under the NEM:BA A&IS regulations. 1365 5.6 Output—sites treated 1366 The DFFE’s Natural Resource Management programmes reported that invasive alien plants were 1367 subjected to control measures over an area of 200 329 ha across all nine provinces in the country. The 1368 average cover of invasive alien plants in this area was 13%, based on the condensed hectares reported. 1369 Additional information on the area managed was supplied by several other agencies, but cannot be 1370 included here as there is a large but unspecified overlap with the area reported by DFFE, from where 1371 agencies derive most of their funding. 1372 A retrospective analysis of the area treated by the DFFE’s NRM programmes between 1998 and 2020 1373 was reported by van Wilgen et al. (2022). Site treatments reached a relatively small proportion (~14%) 1374 of the estimated invaded area. About 72% of treatments were at sites that met at least one criterion 1375 for being a priority site for control (i.e., a strategic water source area, a protected area, or an 1376 endangered or critically endangered ecosystem; see supplementary material S5.13 for more details). 1377 A new development was the implementation of the Greater Cape Town Water Fund which has led to 1378 an expansion of the area subjected to control measures in the invaded water catchments of Cape Town 1379 (Box 5.1). 1380 5.7 Outcome—effectiveness of pathway treatments1 1381 For 50% of the pathways there is either no management, or management was ineffective (for 32% of 1382 pathways the effectiveness of management could not be estimated). There has been little recent 1383 change to the estimated effectiveness of pathway management, with the estimates remaining the 1384 same for 89% of the pathways. In many cases, recently published research confirmed the assessment 1385 made in the previous report (see supplementary material S5.14). A consolidated database of 1386 interceptions made by DALRRD officials during agricultural inspections was made available, finding that 1387 between 2005 and 2019, there were over 25000 interception records, of which 30% were positive (i.e., 1388 had at least one contaminant) and 13% had multiple contaminants (Saccaggi et al. 2021). Quarantine 1389 pests are those that have been assessed through a pest risk analysis, have been deemed to pose an 1390 unacceptable risk to agriculture, and are prohibited from entering the country. Despite the actions 1391 taken to prevent the transport of quarantine species to South Africa (e.g., phytosanitary mitigation 1392 1additional information on inspections by DALRRD and DFFE will be included in the next draft 53 measures that are implemented pre-border), these species continue to be intercepted, although at a 1393 relatively low rate. Species with an unknown quarantine status, that could also pose a threat, are often 1394 intercepted in agricultural inspections (Nnzeru et al. 2021, Saccaggi et al. 2021, Tshikhudo et al. 2021a, 1395 Tshikhudo et al. 2021b). Studies on the pet, aquarium, and traditional medicine trades also confirmed 1396 that the management of these pathways is ineffective, and indicated that regulated species continue 1397 to be illegally sold (Nelufule et al. 2020, Shivambu et al. 2020, Williams et al. 2021, Niemann et al. 1398 2022). In traditional medicine markets, 16 category 1b species, one category 1a species, and one 1399 category 2 species were illegally sold (Williams et al. 2021). A survey of aquarium and pond plant 1400 retailers in Johannesburg used DNA barcoding to identify traded macrophytes, and found that among 1401 the identified species, 12% (9 species) were on the NEM:BA alien and invasive species lists (Niemann 1402 et al. 2022). Interestingly, a survey of pet shops around the country showed that most respondents 1403 (68%) were aware of the NEM:BA regulations, but 71% were against the regulation of the trade, and 1404 58% admitted to losing organisms through escapes (Shivambu et al. 2022). Unfortunately, most pet 1405 traders (83%) were not registered with the pet traders association, and this makes it difficult to 1406 regulate the trade (Shivambu et al. 2022). For one pathway the effectiveness of treatments could be 1407 estimated for the first time, for this pathway, which concerns introductions for conservation, 1408 management was estimated to be partially effective as very few species alien to the country are being 1409 kept on wildlife ranches used for ecotourism (Taylor et al. 2021). 1410 5.8 Outcome—effectiveness of species treatments 1411 Of the 196 species that were reported to have been treated over the 2020–2022 period, control was 1412 regarded as permanent for 12 species, effective for 16 species, ineffective for 11 species, unknown for 1413 130 species, and 14 species targeted for eradication are to be assessed. The effectiveness of species 1414 treatments could, in almost all cases, only be scored for plant species under biological control, with 1415 control scored as permanent in cases where biological control was assessed as complete (Zachariades, 1416 2021; see supplementary material S5.15 for full details). 1417 In terms of specific outcomes, Motitsoe et al. (2020) reported that biological control of the alien 1418 aquatic plant Salvinia molesta by the introduced weevil Cyrtobagous salviniae facilitated the recovery 1419 of epilithic algae and aquatic macroinvertebrate communities. Coetzee et al. (2022) reported that 1420 inundative releases of the biological control agent, Megamelus scutellaris at Hartbeespoort Dam 1421 resulted in a reduction in cover of water hyacinth (Pontederia crassipes) from over 37% to less than 1422 6% over two consecutive years (Box 5.2). Castañeda et al. (2020) monitored native fishes over five 1423 years after the eradication of invasive smallmouth bass (Micropterus dolomieu) from the Rondegat 1424 River in the Western Cape, and concluded that the native fish community had recovered, but that the 1425 removal of smallmouth bass was not sufficient for full recovery of all species (i.e. other threats 1426 54 remained). Additional conservation measures would be needed to secure the population stability and 1427 persistence of endangered fishes. 1428 5.9 Outcome—effectiveness of site treatments 1429 The ongoing absence of any formal systems that monitor the outcomes of site treatments, noted in 1430 previous reports, remains an obstacle to the assessment of the effectiveness of treatments. No recent 1431 research reports or publications were found that have assessed the effectiveness of site treatments. 1432 Nonetheless, Cape Nature assessed the effectiveness of alien plant control measures on 31 protected 1433 area clusters, based on estimates of the cover of alien plants as: effective for 5 protected area clusters; 1434 partial for 20 clusters; ineffective for 3 clusters; and unknown for 3 clusters (see supplementary 1435 material S5.16 for further details). Notably effectiveness was expressed in terms of an increase or 1436 decrease in the cover of invasive alien plants, and not in terms of the recovery of biodiversity and 1437 ecosystem functioning in the target ecosystem (and so somewhat more aligned to an output in terms 1438 of the indicator framework used here). 1439 Keet et al. (2022) assessed the level of compliance with alien plant regulations by comparing the 1440 number of regulated alien plants species in 36 ‘camps’ (staff villages, ranger outposts, and tourist 1441 areas) in the Kruger National Park in 2001 with numbers in 2020 (noting the regulations came into 1442 effect in 2014). The number of alien plant species almost doubled after the first survey (from 231 to 1443 438) likely due to a more systematic search by trained botanists. Despite this, both the number of 1444 regulated species, and species richness per camp declined (by 38% overall and by 56% per camp). The 1445 conclusion was that alien species regulations provided clear guidance for conservation managers, and 1446 that there were promising signs of reductions in targeted alien plant species. 1447 There is also evidence that active restoration of invaded ecosystems may be necessary after the 1448 removal of invasive alien plants. The costs of active restoration interventions might, in some cases, be 1449 economically justifiable, but the cost of fully restoring ecosystem structure, functioning, and 1450 composition in highly degraded ecosystems has rarely been deemed economically justifiable in South 1451 Africa (Holmes et al. 2020; van Wilgen et al. 2022). Generally, government-supported control 1452 operations have not included restoration efforts, at least in part because there is little or no funding 1453 for implementing active restoration projects at the necessary scale—most sites are left for passive 1454 restoration (van Wilgen et al. 2022). 1455 1456 55 Box 5.1 The Greater Cape Town Water Fund 1457 Concern about the growing impact of invasive alien trees on Cape Town’s water supplies led to the 1458 establishment of the Greater Cape Town Water Fund in 2018. The fund was based on a feasibility 1459 study (Turpie et al. 2017) and business case (Stafford et al. 2018) which showed that clearing Cape 1460 Town’s priority water catchments by removing invasive trees could generate annual water gains of 1461 50 billion litres within five years—equivalent to one-sixth of the city’s current supply needs. These 1462 gains could double to 100 billion litres annually within 30 years. This approach was estimated to be 1463 significantly more cost-effective than other water augmentation solutions. 1464 The fund is co-ordinated by the Nature Conservancy (a US-based NGO), and is a partnership between 1465 national, provincial, and local government departments, corporate sponsors (including Nedbank, 1466 Coca-Cola, AB-InBev, and REMGRO), and NGOs (the Nature Conservancy and the South African 1467 branch of the World Wide Fund for Nature). 1468 1469 Box Figure 5.1 Workers from the Greater Cape Town Water Fund removing invasive pine trees from 1470 the catchment of the Theewaterskloof dam (visible in the right-hand background). Photo: Louise 1471 Stafford. 1472 The fund has targeted the catchments of Cape Town’s major supply dams at Theewaterskloof, 1473 Bergriver, Wemmershoek, and Steenbras, as well as the recharge basin of the Atlantis aquifer (Box 1474 Figure 5.1). The fund has a blended funding model and a 30-year time horizon. It has raised ZAR 182 1475 million of the required ZAR 372 million in funding for its first six years of operation, with significant 1476 contributions from corporate sponsors (28% of funds raised to date), philanthropic individuals and 1477 foundations (46%), and the City of Cape Town (26%). 1478 56 The fund’s key objective is to reduce the cover of mature alien trees to below 5% within 30 years, 1479 and restore a cover of natural vegetation where possible. The fund has already spent ~ZAR 100 1480 million, and is now half way to achieving its initial 6-year target of clearing 55 300 ha. About 75% of 1481 the cleared area was upper catchments invaded by alien pine (genus Pinus) trees. The fund uses a 1482 custom-built decision support system to guide its operations. The system tracks all clearing and 1483 follow-up operations, and prioritises sites for interventions. Interventions are also regularly 1484 monitored to assess the effectiveness of operations, as well as ecosystem recovery and social 1485 benefits generated. 1486 The implementation of this fund, which targets carefully prioritised areas, and includes the necessary 1487 components of planning and monitoring provides an exceptional example of the implementation of 1488 best practice in the control of plant invasions with clear goals and timeframes. It is also unique in that 1489 it obtains funding from multiple sources, and provides a model for the planning of similar 1490 interventions elsewhere. 1491 1492 Box 5.2 Successful biological control of water hyacinth on a eutrophic sub-tropical water-body 1493 Water hyacinth (Pontederia crassipes) has caused major impacts world-wide by covering water bodies 1494 in vegetation, reducing oxygen levels in the water, and thereby altering the diversity of freshwater 1495 benthic communities and impacting the provision of ecosystem services (including opportunities for 1496 fishing, and recreational opportunities such as swimming and boating). Biological control has been 1497 highly successful in tropical areas, but in more sub-tropical, eutrophic waters biological control has 1498 been less successful, especially where cooler winter climates prevail. In South Africa authorities have 1499 resorted, at considerable expense, to spraying herbicides from aircraft and boats. However, plants are 1500 able to re-colonise these sprayed areas rapidly, temporarily escaping biological control. This means 1501 that spraying operations need to be constantly repeated, adding another source of chemical pollution 1502 to the waters. 1503 A relatively new addition to the suite of biological control agents was Megamelus scutellaris, which 1504 was first released in South Africa in 2013. This insect was promising because it responds well to mass 1505 rearing, reproduces rapidly, and recovers quickly after periods of cooler temperatures. In addition, it 1506 can be exceptionally damaging to water hyacinth. Insects were mass-reared, and released in a stand-1507 alone intervention on Hartbeespoort Dam in 2018 in the absence of herbicide treatments. 1508 Following frequent inundative releases of the agents, Coetzee et al. (2022) reported that water 1509 hyacinth cover was reduced from over 37% to less than 6% over two consecutive years (Box Figure 1510 5.2). The recommendation was to release the insects often and in high numbers to inundate and 1511 57 overwhelm the water hyacinth and to achieve control at a fraction of the cost of herbicide applications. 1512 This represents a major breakthrough in the control of water hyacinth in South Africa (and potentially 1513 in other sub-tropical and temperate eutrophic water bodies worldwide). 1514 1515 Box Figure 5.2 Declines in the cover of water hyacinth between January 2017 and February 2020 due 1516 to biocontrol by Megamelus scutellaris. Water hyacinth is the bright green against the black water in 1517 the satellite images. This control happened in the absence of herbicide applications. Figure from 1518 Coetzee et al. (2022)1519 58 5.10 Trends in interventions indicators 1520 Indicator Trend Confidence Desired trend 1 Current status and trend Outlook 12. Quality of regulatory framework → Medium ↗ The amendments to NEM:BA and the A&IS Regulations and Lists have improved the regulatory regime slightly. The law reform has clarified some concepts and one of the changes may well help the Department prioritise where to focus scarce law enforcement interventions. However, the fundamental pro blems identified in the previous report have not been addressed, including the absence of a comprehensive strategy to guide implementation of the regulations and lack of flexibility in the regulatory regime. The White Paper is an indication that the Department plans to amend NEM:BA in the near future. However, the White Paper does not address the problems with the current regulatory regime. The development and implementation of a national strategy for biological invasions has the potential to be a milestone in the management of biological invasions in South Africa The development and implementation of a process to regularly and transparently update the regulatory lists informed by the best available scientific evidence is promising. 13. Money spent ↘ Low ↗ An estimated R1.4 billion was spent between 2020 and 2022. This is an underestimate as not all government entities, NGOs or the private sector have provided estimates. The amount spent has been declining in real terms since 2015 (van Wilgen et al. 2022). Government’s ability to fund the control of biological invasions has been reduced due to adverse economic conditions that have prevailed over the past few years. Large increases in funding are unlikely in the near future. The Greater Cape T own Water Fund may provide a new model for such fundraising (Box 5.2). 1→ no change; ↗ an increase; ↘ a decrease 59 Indicator Trend Confidence Desired trend 1 Current status and trend Outlook 14. Planning coverage ↗ Medium ↗ Pathways: 40 of the 44 pathways are assumed to have management plans in place, but these have not necessarily been formalised. No formal plans have been developed by DFFE. There has been no change since the previous report. Species: management plans are still to be assessed, but few of the 559 regulated taxa have plans in place. None of these plans have been formally adopted, nor is the process for formal adoption clear, although landowners are required by law to control species on their land in accordance with such plans, should they exist [NEM:BA Sections 75(4) and 75(5)]. Sites: management plans cover about 14.7% of the area that needs to be managed, and most of these plans have been assessed as partially adequate or inadequate. Several plans are still to be assessed (28 520 km2 of the estimated invaded area in the country is known to have management plans). There is still a need to identify priority pathways, and develop and formally adopt plans to support the management of those pathways. There is a similar lack of formal planning processes to address species and sites. 15. Pathways treated → Low ↗ All pathways through which alien organisms can be introduced require management, and currently 39 of the 44 pathways (89%) are managed to some extent. Most of the pathways that are managed are partially managed (51%), but many (49%) have complete management. There has been no change since the second report. The establishment of the Border Management Authority could result in more co-ordinated management of pathways. The implementation of ballast water management bill would also improve the situation. H owever, there is still a need to identify priority pathways, and develop pathway-focused management for those pathways. 16. Species treated → Low ↗ 196 out of 559 regulated taxa (~35%) have been subjected to some form of management. Most effort is directed towards widespread or damaging species or towards species that are potential eradication targets. Several invasive alien species are expanding their ranges rapidly, so capacity to deal with all species will be further reduced. The national strategy on biological invasions, in concert with the revised CBD biodiversity target on alien species may incentivise greater prioritisation of control efforts against the most damaging listed invasive species, and those that present the greatest future threats 60 Indicator Trend Confidence Desired trend 1 Current status and trend Outlook 17. Sites treated Not assessed ↗ The area that has been treated 2020–2022 is estimated to be 2003 km2, this includes all land parcels that have been worked on by public works alien plant control teams. The estimated total invaded area in South Africa is 194 943 km2, so control operations have therefore reached just over 1% of the estimated invaded area. A recent study estimated that control operations between 1998 and 2020 had reached 14% of the estimated area (van Wilgen et al. 2022). Because control operations are not followed up every year, it may be necessary to examine the extent of treatment over longer periods. There are substantial uncertainties regarding the estimated extent of invasion. Control also often does not cover the full area mapped as having received control, so the 1% (and the 14%) are probably overestimates. It is expected that the area invaded in South Africa will increase, though as for species treated, processes are in place to ensure greater prioritisation of control efforts to ensure priority sites are cleared and kept clear. 18. Effectiveness of pathway treatments → Low ↗ There has been no change to the estimated effectiveness of pathway management for most pathways. For one pathway, releases for conservation, the effectiveness of management could be estimated for the first time, and was estimated to be partially effective. Five pathways are not managed, 17 have ineffective management, one has partially effective management, six have effective management, and one has permanent management. The establishment of the Border Management Authority, and through that the co-ordination of the atborder management of pathways will hopefully improve the efficacy of atborder management. However, there is still a need to measure the efficacy of management using good data, and adapt where required. 19. Effectiveness of species treatments → Low ↗ Effectiveness of species treatments: For most of the 559 regulated species, there is no evidence that any management is taking place (363 species), or the effectiveness of management is not known (130 species). For 14 species that are targets for national eradication, the effectiveness of management still has to be evaluated. Twelve species were assessed as being under permanent control (based on an assessment of complete biological control). For the remainder, control was effective (16 species), partially effective (13 species) or ineffective (11 species). Assessing the effectiveness of species treatments at a national scale is based on changes in the size of the population (for animals) or the extent of invasion (for plants). These are currently not monitored except for some alien plants that are the target of biological control. The absence of a reliable baseline and regular updates will continue to prevent accurate assessments of control effectiveness. When assessed at finer scales, there are examples of partially effective treatments of species at some sites. 61 Indicator Trend Confidence Desired trend 1 Current status and trend Outlook 20. Effectiveness of site treatments → Low ↗ Not assessed. The absence of management plans with clear goals and regular monitoring of those plans makes it difficult to assess effectiveness, which would have to be expressed in terms of progress towards achieving the goal. For some areas where information is available, there are indications that some interventions are at least partially effective, but the goals of management are typically unstated, making such assessments difficult. There is no information to suggest that the situation has changed since the second report. There are no routinely-collected data to assess the effectiveness of site treatments, either in terms of changes in the extent of the area invaded, or in terms of ecosystem recovery following control. Assessments are only possible for small areas that have been the subject of research studies. High-level indicator D. Level of success in managing invasions → Low ↗ To be calculated from pathway, species and site effectiveness once these have been finalised. Making a reasonably accurate assessment of the overall success of managing invasions remains challenging due to the absence of stated goals in management plans against which to assess progress, as well as the absence of activities to regularly monitor progress towards goals. As reported in the second report, these issues need to be urgently addressed, because without them effectiveness cannot be known, management cannot be adaptive, and the impacts and costs of invasions will continue to rise. The proposed national strategy and action plan on biological invasions may help explicitly address these issues. 1521 68 6.1.4. Within-country dispersal rates 1664 On Prince Edward Island the dispersal of invasive plants (e.g., Sagina procumbens and Poa annua) is 1665 likely to occur via wind and with seabirds (Ryan et al. 2003). Evidence from Prince Edward Island, 1666 where humans are absent for years at a time and where alien spread is rapid, suggests that the 1667 unaided pathway is important for alien plants on the islands; we suspect that this is the common 1668 pathway of dispersal for alien species. On Marion Island, it is thought that Sagina procumbens was 1669 spread from the research base by helicopter during annual restocking of the huts (Gremmen and Smith 1670 1999). The construction of a steel helicopter pad at the new research base has likely reduced dispersal 1671 through this pathway, although the helicopter still lands on vegetation at the huts and so might still 1672 be responsible for spreading seeds. It is likely that some propagules are spread by field workers, but 1673 this has not been investigated. 1674 6.2 Species 1675 6.2.1. Number and status of alien species 1676 74 alien taxa have been recorded on the PEIs, with 45 still present, three remain doubtful until 1677 eradication is confirmed, and two are recorded as cryptogenic. Of the alien taxa currently present, 26 1678 are invasive; five are naturalised, but not invasive; and two are present, but not naturalised (Figure 1679 6.3). There are a further six taxa where there is not enough information to assign them to one of the 1680 basic introduction status categories. Therefore, more than half of the alien taxa present on the Prince 1681 Edward Islands have become invasive (58%). Invertebrates comprise the highest proportion of 1682 invasive taxa (69%), followed by plants (23%), fungi (4%), and mammals (4%) (see supplementary 1683 material S6.2). 1684 There are currently no alien taxa in captivity or being cultivated on the Prince Edward Islands, and 1685 despite an active annual search, there have been no marine alien species detected to date (Greve et 1686 al. 2020). Thus, all alien taxa recorded on the Prince Edward Islands are either terrestrial or freshwater 1687 species. There are also no alien birds, reptiles or amphibians (see supplementary material S6.2). 1688 There is uncertainty regarding the status of several species on the island. For example, an unidentified 1689 mite species from the Cillibidae family was first recorded from Marion Island during 1996 or 1997 1690 (Marshall et al. 1999). This family had not previously been recorded in the sub-Antarctic and this 1691 species was considered “likely” an introduced species (Marshall et al. 1999). However, since this initial 1692 collection no progress has been made in determining the identity or status of the species, despite it 1693 frequently being the numerically dominant mite species in some habitats (see e.g. Barendse et al. 1694 2002). 1695 69 1696 Figure 6.3 The status of alien taxa introduced to the Prince Edward Islands as per the Unified 1697 Framework (Blackburn et al. 2011), including species that were present but are no longer (A1), see 1698 supplementary material S6.2 for a break-down into functional groups. The introduction status of six 1699 taxa is not known. 1700 6.2.2. Extent of alien species 1701 Distribution data were available for all but one alien taxon on the PEIs. For Neopygmephorus sp., it is 1702 unclear if the taxon is present on Prince Edward Island. 1703 Estimations from a 2008 study suggested that less than 5% of the Prince Edward Islands had been 1704 covered by invasive plants (Gremmen & Smith 2008). In a more recent study, le Roux et al. (2013) 1705 determined that alien plant species were present in 42% of Marion Island’s half minute grid cells 1706 (hmgcs are ~0.59 km2, roughly 926 m by 635 m), and in 53% of Prince Edward Island’s hmgcs. Sagina 1707 procumbens (166 hmgcs), Poa annua (204 hmgcs) and Cerastium fontanum (162 hmgcs) are the most 1708 widespread species at both islands (DFFE 2010, le Roux et al. 2013, Mairal et al. 2022). For occupancy 1709 details of each species, see the PEIs Species List in Appendix 71. 1710 6.2.3. Abundance of alien species 1711 Information for Marion Island will be included in the next draft. 1712 6.2.4. Impact of alien species 1713 Of the 20 taxa assessed using the EICAT scheme, one had a massive impact (house mouse) and four 1714 had major impacts (Table 6.3, see Supplementary Material for the approach taken). The impacts of 1715 individual invasive taxa have been quantified in a number of cases for Marion Island (e.g. for the now 1716 1Additional information on species occurrences will be added to the next draft. 70 eradicated Felis catus (van Rensburg and Bester 1988; Hunter 1990), for Mus musculus (Crafford 1990; 1717 Jones et al. 2019), and for the grass Agrostis stolonifera (Gremmen 1997, Gremmen et al. 1998)). Even 1718 though no EICAT assessments have been formally undertaken and reviewed for the PEIs, seven species 1719 (four currently present) possess a global published EICAT assessment (three plant species have a 1720 moderate impact and the house mouse a massive impact). 1721 Table 6.3 The number of alien taxa with different levels of recorded environmental impacts on the 1722 Prince Edward Islands (PEIs). Taxa were assigned to various categories of impact based on studies from 1723 the PEIs (Greve et al. 2017), and not based on global EICAT assessments. 1724 Taxon Environmental Impact (~EICAT) Data Deficient Minimal Minor Moderate Major Massive Mammals 0 0 0 0 0 1 Microbial species 0 0 0 1 0 0 Terrestrial and freshwater plants 1 3 2 2 4 0 Terrestrial invertebrates 22 0 5 1 0 0 1725 The greatest recorded impacts were associated with Mus musculus subsp. domesticus (house mouse). 1726 The house mouse is fortunately only present on Marion Island, but it has had impacts at the ecosystem 1727 (Crafford 1990) and species levels affecting the island’s only shorebird (Huyser et al. 2000), seabirds 1728 (Jones et al. 2019, Jones and Ryan 2010, Dilley et al. 2016), native vegetation (Phiri et al. 2009), and 1729 invertebrates (van Aarde et al. 2004). Negative impacts have been documented for plant species 1730 survival (Azorella selago; Phiri et al. 2009) and reproduction (Uncinia compacta; Chown and Smith 1731 1993), invertebrate abundance, biomass and body size (Chown and Smith 1993; Crafford and Scholtz 1732 1987; Treasure and Chown 2014; McClelland et al. 2018), and albatross chick survival (Jones and Ryan 1733 2010, Dilley et al. 2017). House mouse burrowing also alters sediment movement rates (Eriksson and 1734 Eldridge 2014), and likely impacts on nutrient cycling (Crafford 1990b; Smith and Steenkamp 1990). 1735 Evidence shows that there has been a shift in mouse behaviour towards increasing predation on 1736 seabirds’ chicks, including recent evidence of mice starting to attack adult seabirds (Jones et a. 2019). 1737 Arguably such a behavioural shift means the impact due to mice has increased markedly recently, 1738 emphasising the importance of achieving eradication soon. 1739 Various plants, including the grass Agrostis stolonifera, have had major impacts on native vegetation 1740 and soil fauna communities (Gremmen 1997, Gremmen et al. 1998). Very little has been documented 1741 on the impacts of terrestrial invertebrates. Lastly, the fungal microbe Botryotinia fuckeliana was found 1742 to significantly affect the distribution and abundance of a native species (Kloppers and Smith 1998). 1743 1744 71 6.3 Sites 1745 6.3.1. Alien species richness1 1746 Alien plant species richness is highest close to the Marion Island base and meteorological station, and 1747 high along the northern and eastern coastal areas, particularly in areas with current or historic 1748 anthropogenic disturbances (e.g. research field stations) (le Roux et al. 2013). 1749 6.3.2. Relative invasive abundance 1750 The mean cover of all invasive plant species is 1.8% on Marion Island (Greve unpublished data). This 1751 estimate is based on 475 plots of 3 x 3 m that are spread across the island. Given that these plots cover 1752 only a small percentage of the island, confidence in this estimate is low. There is spatial variation in 1753 the relative invasive abundance across Marion Island. Coastal habitats are generally more invaded 1754 than inland habitats. No data on the relative abundances of alien plants are available for Prince Edward 1755 Island. 1756 For both islands, the relative invasive abundance of invertebrates varied strongly between habitat 1757 types and, for Marion Island, along an altitudinal gradient (Figure 6.4). Collembola are relatively well 1758 surveyed, and have relative invasive abundance varying between 0 and 2% on Prince Edward Island 1759 and between 0 and 90% on Marion Island (mean relative abundance = 28%; Treasure et al. 2019, 1760 Chown et al. 2022). The relative invasive abundance of Collembola is highest at lower altitudes, and 1761 in bryophyteand fern-dominated vegetation types. Spiders have only been adequately sampled on 1762 Marion Island (and only from five locations on the eastern side of the island) to document relative 1763 invasive abundance, and data shows relative invasive abundance varying from 0 - 98% (mean = 37%; 1764 Khoza et al. 2005). The relative abundance of alien spiders was lowest at the two sites with the highest 1765 elevation on the island. Alien mites comprise 0 - 26% of all mites on Prince Edward Island (mean = 8%; 1766 Hugo et al. 2006) and 3 - 28 % of mites on Marion Island (mean = 14%; Barendse et al. 2002). However, 1767 due to uncertainty regarding the identity (and status) of Cillibidae sp. nov., which comprises c. 95 - 1768 100% of the alien mite individuals sampled from the islands, there is considerable uncertainty in these 1769 estimates. Relative invasive abundance of Isopoda is 100% due to the absence of native species within 1770 the taxon. Relative abundance data for some taxa (e.g., Insecta) are not available due to the lack of 1771 complete surveys (i.e. not all species within the taxon recorded during sampling). 1772 1Information for Prince Edward Island will be added to the next draft. 72 1773 Figure 6.4. Relative abundance of alien a) springtails on Prince Edward Island, b) springtails on Marion 1774 Island, c) mites on Prince Edward Island, and d) mites on Marion Island. Labels indicate vegetation 1775 type and, where appropriate, the plant species or the altitude sampled within the vegetation type. 1776 Note that the y-axis limits differ between panels. Biotic: Poa = Biotic grassland and herbfield: Poa 1777 cookii; Azorella = Azorella selago; Salt-spray = Coastal salt-spray; Cotula = Cotula plumosa; Crassula = 1778 Crassula moschata; Acaena = Acaena magellanica; Blechnum = Blechnum penna-marina; Blephar = 1779 Blepharidophyllum densifolium; high-alt = high-altitude; James = Jamesoniella colorata; mid-alt = mid-1780 altitude; Sanionia = Sanionia uncinata. 1781 6.3.3. Impact of invasions1 1782 Gremmen (1997) estimated that invasion by grasses (plots dominated by Agrostis stolonifera but with 1783 presence of other aliens) led to a 50% decrease in native vegetation richness in invaded drainage lines. 1784 Bryophyte biomass was also 16 times lower in these habitats, but the species richness of 1785 macroinvertebrates and mites was higher in invaded areas (Gremmen et al. 1998). 1786 6.4 Interventions 1787 6.4.1. Input—quality of the regulation framework 1788 1If possible, a biodiversity intactness score and estimates of change in ecosystem functioning will be added to a future draft. 73 The PEIs have the highest level of protection afforded to any natural area under South African law. 1789 The islands were declared a Special Nature Reserve in 1995 and are reserved primarily for scientific 1790 research and environmental monitoring, and recreation activities are prohibited (DFFE 2010). The PEIs 1791 were designated a Ramsar Wetland Site of International Importance in 2007. In 2013, the Prince 1792 Edward Island Marine Protected Area was formally declared. Alien species are not allowed into the 1793 Prince Edward Islands, therefore permits cannot be issued, and this ban includes biological control 1794 agents. 1795 The NEM:BA A&IS Regulations (2020) list 12 out of the 45 taxa currently present on the islands (Table 1796 6.4). Even though Holcus lanatus has not been seen on Marion Island since 2012, there was a proposal 1797 for the addition of the species to the NEM:BA A&IS Regulations as category 1a on 8 February 2021. 1798 Interestingly, none of the species currently regulated for the PEIs are regulated for mainland South 1799 Africa. As of December 2022, no risk analyses or risk assessments have been performed specifically 1800 for the PEIs. 1801 Table 6.4. Alien taxa listed in the NEM:BA A&IS Regulations for the Prince Edward Islands (2020) or 1802 for which an eradication plan has been developed (cf. the PEIs Species List). Control implemented 1803 obtained mainly from DEA and DST-NRF 2012-2013, last updated in 2021, or indicated otherwise. 1804 scientificName vernacularName RegulatoryListing Notes on control implemented Agrostis castellana Bent grass 1a Prince Edward Island 1b Marion Island None implemented (Greve et al. 2017, DEA and DSTNRF 2021) Agrostis gigantea Black bent grass 1a Mechanical removal of aboveground biomass and herbicide application (Glyphosate; 2.5% Kilo Max) Agrostis stolonifera Creeping bent grass 1a Prince Edward Island 1b Marion Island None implemented (successful eradication deemed unfeasible by Greve et al. 2017) Alopecurus geniculatus Marsh foxtail 1a Manual removal was applied, assumed to be no longer present since 2012 (Greve et al. 2017) Cerastium fontanum Common mouseear chickweed 1b None implemented (Greve et al. 2017, DEA and DSTNRF (2021) Elymus repens (syn. Elytrigia repens) Couch grass 1a Mechanical removal of aboveground biomass and herbicide application (Glyphosate; 2.5% Kilo Max 700g/kg). This grass is believed to have been successfully eradicated (between 2012 and 2016), but this needs to be monitored for confirmation Festuca rubra Creeping red fescue 1a Herbicide application (Glyphosate; 2.5 Kilo Max) Holcus lanatus Common velvet grass Not listed The species was manually removed in 2012, site and surrounding areas are monitored monthly since to detect any regrowth or new plants Luzula multiflora Woodrush 1a Herbicide application (Glyphosate; 2.5% Kilo Max). A genetic study has been recommended to confirm that it differs from the native subantarctic Luzula species (and so unequivocally alien) 74 scientificName vernacularName RegulatoryListing Notes on control implemented Mus musculus subsp. domesticus House mouse 1a Marion Island Bait and traps are deployed outside the base and huts to protect food and human health (Wolfaardt pers. comm. 2022). Mice are not, yet, otherwise subject to control Poa pratensis Kentucky bluegrass 1a Prince Edward Island 1b Marion Island None implemented (Greve et al. 2017, DEA and DSTNRF (2021) Porcellio scaber Common rough woodlouse Not listed The woodlouse is believed to have been successfully eradicated in 2012, but this needs to be monitored for confirmation. Eradication is recommended via application of pyrethroid (Super Crackdown) Rumex acetosella Sheep sorrel 1a Mechanical removal of aboveground biomass and herbicide application (Glyphosate; 2.5% Kilo Max 700g/kg) Sagina procumbens Birdeye pearlwort 1b None implemented (successful eradication deemed unfeasible by Greve et al. 2017) Stellaria media Common chickweed 1a Prince Edward Island 1b Marion Island Herbicide application (2.5% Kilo Max). 1805 6.4.2. Input—money spent 1806 It was not possible to get a full estimate of the money spent managing biological invasions on the 1807 PEIs. 1808 In 2006 there was a specific targeted effort to control the invasive plant Elymus repens, where above-1809 ground material and some of the below-ground rhizomes were removed, and herbicide was applied. 1810 The total cost of the operation was R201 378 which included human resources as well as helicopter 1811 trips to transport the removed biomass. Otherwise, the DFFE budget for herbicides (two different 1812 types) and equipment, including personal protective equipment, to control of alien species on the PEIs 1813 2011–2022 was 58 664.55 ZAR (see supplementary material S6.3). The only pesticide applied on 1814 Marion Island to control invertebrates was donated, the value of this has not been obtained yet. 1815 The major cost controlling biological invasions on the island will be the time of the environmental 1816 control officers (ECOs). ECOs perform various duties, and a method of estimating their time spent 1817 on alien species monitoring and control has not, as yet, been made. However, given the discrete 1818 nature of the PEIs it should be possible to estimate the full cost of the control of invasions. 1819 6.4.3. Input—planning coverage 1820 There are two management plans previously developed for the PEIs: one published in 1996, and 1821 another in 2010 (Version 0.2). The second plan was officially adopted by the then DEA in 2014. 1822 Management plans were set to be revised and updated every four years, but the latest updated 1823 management plan is only scheduled to be circulated for public comment around mid-2023. Therefore, 1824 75 the estimates provided for this indicator and subsequent ones are related to the management plan 1825 from 2010. 1826 The current management plan determines the quarantine and biosecurity measures to be applied to 1827 introduction pathways, and has recommendations for the management of invasive species. There is 1828 only one management plan, and not separate plans for specific species or taxonomic groups. The 1829 Prince Edward Islands Management Plan includes both islands, and so all sites have a management 1830 plan in place. 1831 All eight active introduction pathways, besides the unaided pathway for which management is 1832 impractical, are covered in the plan. The plan outlines a large set of biosecurity control measures to 1833 reduce the risk of introducing alien species, either with the vessel, with people and their belongings, 1834 and/or with cargo. The intentional introduction of any alien live organisms is prohibited. There are 1835 specific regulations on how the vessel’s hull must be cleaned of fouling taxa before every annual 1836 voyage, and ballast water cannot be discharged within 200 nautical miles of the islands (DFFE 2010). 1837 The plan also regulates the number of expeditioners that can travel to the islands (and the frequency 1838 and duration in the case of Prince Edward Island), what they can bring in their luggage, and the 1839 equipment they are allowed to transport. 1840 As part of the Management Plan, a joint initiative between the then Department of Environmental 1841 Affairs and the then DST-NRF Centre of Excellence for Invasion Biology developed an eradication plan 1842 (‘Eradication, monitoring and control of alien and invasive alien species on Marion Island’) for six 1843 priority invasive plant species and one invertebrate, which is revised and updated every year by the 1844 DFFE alien species management team. The Management Plan considers only 14 species as invasive, 1845 although this report found evidence of invasiveness for 26 of the 45 aliens currently present on the 1846 Prince Edward Islands. Out of 12 species present on the Prince Edward Islands which are listed under 1847 the NEM:BA A&IS Regulations (2020), only seven are included in the eradication plan. There are also 1848 two species in the eradication plan which are deemed a priority for eradication that are not currently 1849 listed under the national regulations. 1850 The house mouse has a separate eradication project, namely ‘Mouse-Free Marion’ 1851 (https://mousefreemarion.org/), which is currently in its planning phase and funds are being raised 1852 with the aim of implementing the project in 2025. The planned cost for the mouse eradication is ~ZAR 1853 450M. It is a partnership between the Department of Forestry, Fisheries and the Environment and 1854 BirdLife South Africa. 1855 6.4.4. Output—pathways treated 1856 76 A DFFE Gear Checks document provides guidance for all expeditioners on how to clean their gear, 1857 clothes and personal equipment, and to check for the presence of alien species or propagules during 1858 packing before departure. A further Biosecurity Check is conducted en route on board the SA Agulhas 1859 II, where all participants’ outer field gear and equipment not packed away in the cargo hold is 1860 inspected for any biological material. All participants must sign the ‘Biosecurity self-audit checklist and 1861 declaration’ confirming that they have adhered to DFFE’s biosecurity measures. Measures are also in 1862 place to reduce the movement of propagules (e.g., seeds) within Marion Island (within-country 1863 pathways) from sites close to the base to less invaded sites. There is a ‘minimum Velcro policy’ given 1864 that propagules are known to attach to this material. All new standard issue protective clothing 1865 supplied by DFFE is Velcro-free as from mid-2022. 1866 Additional measures are in place before travelling to Prince Edward Island, e.g. personnel dropped 1867 directly at Prince Edward first (i.e. no prior deployment at Marion), new camping equipment and 1868 protective clothing, etc. 1869 Containers which transport cargo need to be properly cleaned with a high-pressure hose before 1870 packing and storing cargo, and cargo (including machinery) must be inspected to check for the 1871 presence of alien organisms or propagules. The same biosecurity rules are applied for other vessels as 1872 for the SA Agulhas II. All this is clearly stated in the 2010 management plan (Goal 5.1, DFFE 2010). 1873 To avoid alien taxa from being transported with food (unintentional contamination), some organic 1874 products are banned from being transported to the islands (e.g. fresh fruit and vegetables, yoghurt), 1875 and others must be irradiated (e.g. eggs) or frozen before they can travel (e.g., meats and vegetables). 1876 6.4.5. Output—species & sites treated 1877 Of the 12 regulated invasive taxa currently present, seven taxa have been subjected to some form of 1878 management since 2012 (Marion Island only; no species have been treated on Prince Edward Island) 1879 when the eradication plan was developed (Table 6.4). 1880 Seven vascular plant species, one invertebrate species (Porcellio scaber), and the house mouse are 1881 currently being treated on Marion Island. All seven plant species and the isopod Porcellio scaber have 1882 been treated at all the sites (ranging from one to three locations) where the species are known to 1883 have occurred (Neethling 2019, DEA and DST-NRF 2021). These sites are all on the eastern side of 1884 Marion Island, with all but one site within close proximity to the research base (i.e. < 1 km; the distant 1885 site is < 5 km from the research base). The house mouse is being controlled at the research base and 1886 all field huts, but this only represents a very small fraction of the species range on Marion Island (DEA 1887 & DST-NRF 2021). 1888 77 6.4.6. Outcome—effectiveness of pathway treatments 1889 Details to be provided in the next draft. 1890 6.4.7. Outcome—effectiveness of species & site treatments 1891 The effectiveness of species treatments is assessed on Marion Island each year by the ECOs in terms 1892 of herbicide ‘kill rate’ (percentage of plants or plant cover killed per area treated) and regrowth for 1893 invasive plants, with two species having a 90-100% kill rate, two species having a 60-80% kill rate, and 1894 one species a 30-40% kill rate. Second herbicide application effects are still being monitored. However, 1895 the assessments are not performed in a systematic manner. 1896 Three species are thought to no longer be present due to successful chemical and mechanical 1897 interventions, two plants Alopecurus geniculatus and Holcus lanatus, and the invertebrate Porcellio 1898 scabus. However, these species are still included in the eradication plan for monitoring until 1899 eradication is confirmed. 1900 The effectiveness of the control reported for some species conflicts between sources. For example, 1901 for Agrostis gigantea the herbicide effectiveness to kill the plants was reported to be between 90-1902 100% (DEA and DST-NRF 2021), but Neethling's report (2019) states that although the species was 1903 killed at three sites, new populations were found a short distance from each of those sites. However, 1904 control appears to have been entirely effective for two grass species (Elytrigia repens and Holcus 1905 lanatus), with these species currently being absent from the single sites from which each species was 1906 known in the mid-2000s. The treatment of the isopod Porcellio scaber also appears to have been 1907 entirely effective. Treatment initially comprised targeted searches by researchers (Janion-Scheepers, 1908 pers comm 2022), and after the initiation of chemical control in 2012, no further individuals have been 1909 observed (latest data from 2017). The quality of the implementation of the management plans for 1910 these species is potentially adequate, but there appears to be a lack of up-to-date management plans 1911 and progress reports often contain inadequate detail. As a result, the quality of implementation of 1912 management plans is not known. 1913 No data are available to assess the effectiveness of the control of house mice at the research station 1914 and field huts, but given the small fraction of the species range that these structures comprise and the 1915 species ability to move across the landscape, it can be assumed that the impact is negligible. 1916 The treatments applied to alien plant species appear to be effective at killing individuals [30–100% 1917 mortality of individual plants (MME 2017, DEA & DST-NRF 2021)], but accurate monitoring at the site 1918 level is lacking (Invasive Alien Plant Programme 2019). 1919 84 Scalera, R., Essl, F., & Roy, H. E. (2016). 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Springer, Berlin, pp 489-512. 2323 Zenni, R. D., Essl, F., García-Berthou, E., McDermott, S. M. (2021). The economic costs of biological invasions 2324 around the world. NeoBiota 67: 1–9. 2325 2326 87 Links to supplementary material and appendices 2327 All the supplementary material and appendices will be available between 20 December 2022 and 28 2328 February 2023 at https://tinyurl.com/mr2mu6xz 2329 Copies of the files will be permanent available at the links below. 2330 Appendix 1. List of data sources http://dx.doi.org/10.5281/zenodo.7433093 2331 Appendix 2. The species list http://dx.doi.org/10.5281/zenodo.7433103 2332 Appendix 3. Metadata for the species list http://dx.doi.org/10.5281/zenodo.7433113 2333 Appendix 4. Workflows http://dx.doi.org/10.5281/zenodo.7433130 2334 Appendix 5. Pathways change tracker http://dx.doi.org/10.5281/zenodo.7433141 2335 Appendix 6. “Permits issued in respect of South Africa's National Environmental Management: 2336 Biodiversity Act's Alien and Invasive Species Regulations over the period October 2014–December 2337 2020” http://dx.doi.org/10.5281/zenodo.5101758 2338 Appendix 7. The Species List for the Prince Edward Islands 2339 http://dx.doi.org/10.5281/zenodo.7433583 2340 Appendix 8. Metadata for the Species List for the Prince Edward Islands 2341 http://dx.doi.org/10.5281/zenodo.7433607 2342 Supplementary material http://dx.doi.org/10.5281/zenodo.7415497 2343 2344 For reference this report is available at http://dx.doi.org/10.5281/zenodo.7414804 2345 2346