1
Limnological desc ip ion o he Ta elo lagoon (SW Spain).
L. Se ano1, M. Reina1, A. A echede a1, M. A. Casco2& J. Toja1
1Depa amen o de Biología Vege al y Ecología. Uni e sidad de Se illa. Ap. 1095. 41080. Se illa. Spain.
2P.C. Ficología. Museo de La Pla a. Ap. 1900. La Pla a. A gen ina.
ABSTRACT
The lagoon o Ta elo (SW, Spain) is a pe manen aqua ic sys em loca ed nea he es ua y o he Guadalqui i Ri e . The wa e
quali y o his lagoon was poo du ing he s udy pe iod (Janua y 2001-Augus 2002): he high wa e u bidi y hinde ed he
g ow h o subme sed aqua ic mac ophy es and he bo om wa e was deple ed o dissol ed oxygen in sp ing-summe despi e
he mixing c ea ed by he wind. The concen a ion o plank onic chlo ophyll a anged om 74.2 o 330.7 µg l-1 in he su ace
wa e and om 34.8 o 256.2 µg l-1 in he bo om wa e . The blooms o cyanobac e ia (>106 cells ml-1) we e equen and con-
ibu ed o he gene a ion o episodic anoxia in he wa e column. Consequen ly, he numbe o bo h plank onic and ben honic
axa we e e y low. Two axa o cyanobac e ia, Aphanocapsa holsa ica and Mic ocys is sp., occu ed wi h an a e age ela i e
abundance >30%. The mos commonly ound axa we e Oscilla o ia sp., Oocys is sp., Oscilla o ia limne ica, Ch oococcus sp.
and Mono aphidium ci cinalle. Popula ion explosions (>2000 ind l-1) we e common in o i e s such as B achionus plica ilis
and Ke a ella opica. The densi y o Chi onomus plumosus in he sedimen su ace declined ab up ly when oxygen was sca -
ce. The empo al a iabili y o nu ien concen a ions anged om e en -scale pulses o seasonal ime scales. Ni ogen ollo-
wed a seasonal pa e n o loading in win e and deple ion in summe , whe eas he a ailabili y o o-P in he wa e oscilla ed in
pulses. The concen a ion o o-P in he in e s i ial wa e o he sedimen peaked in e mi en ly du ing he s udy pe iod and i
was posi i ely co ela ed wi h he concen a ion o o-P in he bo om-wa e ( =0.698, P<0.05). On a e age, he concen a ions
o o ganic ma e and To -P in he sedimen we e ela i ely low (7 % and 456 µg gDW-1, espec i ely), and bo h a iables we e
highly co ela ed ( =0.853, P<0.01). The majo i y o he sedimen P was o ganic, indica ing he g ea con ibu ion o he
au och honous p oduc ion o he sedimen load. I can be expec ed ha he in e nal P loading will inc ease wi h ime and lead
he sys em o a highe ophic deg ee.
Keywo ds: eu ophica ion, wa e quali y, P- ac iona ion, cyanobac e ia, whi e-headed duck, Oxyu a leucocephala.
RESUMEN
La laguna de Ta elo (SO España) es un sis ema acuá ico pe manen e si uado ce ca del es ua io del Río Guadalqui i . La cali-
dad del agua de es a laguna ue pob e du an e el pe íodo es udiado (ene o 2001-agos o 2002): la ele ada u biedad del agua
limi ó el c ecimien o de plan as acuá icas sume gidas y no se de ec ó oxígeno disuel o en el ondo de la columna de
agua du an e la p ima e a- e ano a pesa de la mezcla gene ada po el ien o. La concen ación de clo o ila planc ónica osci-
ló en e 74.2 y 330.7 µg l-1 en la supe icie y, en e 34.8 y 256.2 µg l-1 en el ondo de la laguna. Las p oli e aciones masi as
de cianobac e ias ue on ecuen es (>106 cells ml-1) y con ibuye on a la apa ición de episodios de anoxia en la columna de
agua. En consecuencia, el núme o de axa an o en el planc on como en el ben os ue muy bajo. Dos cianobac e ias,
Aphanocapsa holsa ica y Mic ocys is sp., alcanza on una abundancia ela i a p omedio >30%. Los axa más comunes en el
i oplanc on ue on: Oscilla o ia sp., Oocys is sp., Oscilla o ia limne ica, Ch oococcus sp. y Mono aphidium ci cinalle. Las
poblaciones de o í e os como B achionus plica ilis y Ke a ella opica expe imen a on explosiones de más de 2000 ind l-1. La
densidad de Chi onomus plumosus en la supe icie del sedimen o disminuyó d ás icamen e a bajas concen aciones de oxíge-
no. La concen ación de nu ien es mos ó una amplia a iabilidad empo al: desde pa ones es acionales has a pulsos in e -
mi en es. El N siguió un pa ón es acional de en iquecimien o en in ie no y desapa ición en e ano, mien as que la disponibi-
lidad de o-P osciló en pulsos. La concen ación de o-P en el agua in e s icial del sedimen o, que siguió una e olución de picos
y alles a lo la go del pe íodo de es udio, se co elacionó con la concen ación de o-P en el agua del ondo ( =0.698, P<0.05).
Las concen aciones p omedio de ma e ia o gánica y To -P en el sedimen o ue on ela i amen e bajas (7 % y 456 µg gDW-1,
espec i amen e) y, ambas a iables se co elaciona on ue emen e ( =0.853, P<0.01). La mayo pa e del P sedimen a io e a
de composición o gánica, lo que indica la impo ancia de la p oducción au óc ona en la ca ga de nu ien es del sedimen o. Es
espe able que la ca ga in e na de P aumen e en el iempo ele ando el ni el o ico de es e sis ema.
Palab as cla e: eu o ización, calidad del agua, accionamien o de P, cianobac e ias, mal asía, Oxyu a leucocephala.
Limne ica 23(1-2): 1-10 (2004)
© Asociación Española de Limnología, Mad id. Spain. ISSN: 0213-8409
Limne ica 23(1-2) 11/10/04 10:04 Página 1
INTRODUCTION
The lagoon o Ta elo (SW, Spain) is a pe ma-
nen aqua ic sys em loca ed a 3 km om he
es ua y o he Guadalqui i Ri e in he limi o
he illage o Sanlúca de Ba ameda wi h he
Doñana Na u al Pa k. The bed o he lagoon was
o igina ed by exca a ion o he ex ac ion o
sand and o he d y ma e ials. The pi was e en-
ually looded h ough seepage om he es ua y
du ing win e 1989. Since hen, i has become
an impo an b eeding si e o he Whi e-headed
duck (Oxyu a leucocephala). Fo his eason
his si e is unde p o ec ion o he Doñana
Na u al Pa k. Howe e , his lagoon is loca ed in
an ag icul u al a ea o in ensi e ac i i y and i is
ed by he i e bed aqui e o he Guadalqui i
Ri e , which has long been su e ing a se e e
ni a e pollu ion (Na a o Al a gonzález e al.,
1993). Consequen ly, a e y high p oduc i i y
can be expec ed in his lagoon ha has changed
om a sys em wi h a dense subme sed mac o-
phy e de elopmen o ano he domina ed by
phy oplank on in ecen yea s.
The coas al lagoons a e e y dynamic sys-
ems, he e o e assessing he scale o a ia ion
and he ange o ansi ional s ages hey pass
h ough a e basic ools o hei managemen
(Comín e al., 1999). This s udy desc ibes he
limnology o he lagoon o Ta elo om Janua y
2001 o Augus 2002 ocusing on i s wa e qua-
li y. The nu ien dynamics has been add essed
in ime and space by s udying he changes in he
e ical s uc u e o he wa e column and i s
in e ac ion wi h he sedimen .
MATERIAL AND METHODS
The lagoon was sampled mon hly be ween
Janua y 2001 and Augus 2002 a an open si e
(3-4 m deep) and a li o al si e (1.5-2.5 m deep).
A day-cycle sampling was pe o med in May
and June 2001. Ve ical p o iles o empe a u e,
dissol ed oxygen and pH we e measu ed in si u
wi h a p obe. The ligh compensa ion poin was
es ima ed as 2.7 imes he dep h o he Secchi
Disk (Ma gale , 1983). Conduc i i y (ATC) was
measu ed in he labo a o y. Wa e samples we e
aken in duplica es om he su ace and he bo -
om o he wa e column a bo h si es using an
elec ical bilge pump. Wa e was il e ed
h ough Wha man GF/C il e s in he labo a o y.
Chlo ophyll awas ex ac ed wi h me hanol in 3
eplica es pe sample (Ma ke e al., 1980) and
i s concen a ion was calcula ed using Talling &
D i e `s o mula (Vollenweide , 1969). The ol-
lowing chemical concen a ions we e measu ed
in he wa e samples in 2-3 eplica es: o al sus-
pended solids (g a ime y), o ganic suspended
solids (g a ime y a e igni ion a 450 ºC, 5 h),
Cl-(APHA, 1985), SO42- (Rodie , 1981), o al
alkalini y (Gol e man e al., 1978), NO2-
(S ickland & Pa sons, 1972), NO3-(Gol e man,
1991), o-P (Mu phy & Riley, 1962), NH4+by
nessle iza ion (Rodie , 1981), and o al phos-
pho us (To -P) a e acid diges ion (De G oo &
Gol e man, 1990). Sedimen s we e collec ed
wi h an Ekman-Bi ge bo om sample . In he
labo a o y, sedimen s we e no ea ed (nei he
d ied no ozen) and s o ed a 4 °C. The con-
cen a ion o o ganic ma e in he sedimen was
es ima ed in 3-4 eplica es by loss on igni ion
(450 °C, 5 h). The To -P concen a ion in he
sedimen samples was measu ed a e acid
diges ion (De G oo & Gol e man, 1990) o he
igni ed sedimen . The concen a ion o o al N
in he sedimen was es ima ed as he concen a-
ion o NH4+measu ed a e nessle iza ion o
he diges ed sedimen . The in e s i ial wa e was
ob ained by cen i uga ion (12 000 .p.m., 15
min) and he concen a ion o o-P was measu ed
as be o e. The P- ac iona ion o he sedimen
was pe o med in duplica es o a sample collec -
ed in May 2001 om he open si e. A po ion o
he sedimen sample was sie ed h ough a ny al
mesh o 0.1 mm po e size ( ine sedimen ). Bo h
he ine sedimen and he unsie ed sedimen
( o al sedimen ) we e ac iona ed by sequen ial
ex ac ion wi h chela ing compounds ollowing
he EDTA’s me hod (Gol e man, 1996).
Lugol p ese ed samples o phy oplank on
we e obse ed acco ding o he U e möhl`s
(1958) echnique o enume a ion. Zooplank on
2Se ano e al.
Limne ica 23(1-2) 11/10/04 10:04 Página 2
samples we e collec ed by il e ing 5-10 l o
wa e h ough a ny al mesh o 63 mm po e size
and p ese ed in 4% o maldehyde. The ben hic
in e eb a es we e collec ed wi h an Ekman-
Bi ge bo om sample o 144 cm2o su ace and
p ese ed in 70% e hanol o u he examina-
ion wi h a binocula mic oscope.
Rain all da a was ob ained om he me eo olog-
ical s a ion o “Palacio de Doñana” (RBD-CSIC).
RESULTS
The wa e dep h anged om 3 o 4 m a he
open si e du ing he s udy pe iod. The elec ical
conduc i i y (ATC) anged om 9.4 o 13.5 mS
cm-1. Wa e was ich in Cl-and SO42- and
anged om 125 o 137 meq l-1and om 42 o
47 meq l-1, espec i ely, whe eas o al alkalini y
was much lowe (2-3 meq l-1).
The e ical p o ile o empe a u e changed
wi hin a e y na ow ange om he op o he
bo om o he wa e column (0.5-1.5 °C in win-
e and 3-5.5 °C in summe ). A weak he mal
s a i ica ion de eloped du ing he day in sum-
me , sugges ing ha his lagoon was polymic ic.
The concen a ion o dissol ed oxygen changed
widely ac oss he wa e column du ing he s udy
pe iod (Table 1 and Figu e 1). The concen a ion
o dissol ed oxygen in he su ace wa e was
always highe han in he bo om wa e , excep o
an episodic anoxia in June 2001 when bo h con-
cen a ions we e ze o, o when he whole wa e
column was oxygena ed due o s ong winds
(Sep embe -Decembe 2001). Consequen ly, he
Limnology o Ta elo Lagoon 3
Table 1. Minimum and maximum alues o se e al a iables in he su ace and bo om o he wa e column a he open si e du ing he s udy
pe iod (Janua y-Decembe 2001 and Janua y-Augus 2002). Valo es mínimos y máximos de di e sas a iables en la supe icie y el ondo de la
columna de agua du an e el pe íodo de es udio.
2001 2002
Su ace Bo om Su ace Bo om
Tempe a u e (°C) 14.4-28.5 14.4-27.3 13.2-26.2 11.9-25.0
D.O. (mg l-1) 0.0-20.0 0.0-19.4 2.2-19.2 0-5.9
pH 6.3-9.6 6.3-9.1 5.6-9.5 5.5-8.8
Chl a(µg l-1) 74.2-226.6 34.8-174.5 115.2-330.7 105.6-256.2
T.S.S. (mg l-1) 25.6-60.5 24.9-56.5 49.0-238.3 111.7-200.0
NO3-(mM) 0.0-20.3 0.0-11.4 0.0-8.0 0.0-1.6
NO2-(µM) 6.4-946.6 13.4-961.3 7.4-312.0 3.5-98.8
NH4+(mM) 0.1-2.2 0.1-2.7 0.4-3.0 0.7-5.3
o-P (µg l-1) 1.8-97.4 3.7-150.1 7.1-48.5 6.5-234.9
To -P (µg l-1) 101.6-600.0 135.3-666.6 155.9-317.6 216.3-528.5
DIN/To -P 46.7-1281.6 42.8-936.2 73.8-784.0 59.5-215.7
Figu e 1. Concen a ion o dissol ed oxygen in he su ace
(solid line) and bo om wa e (dashed line) a he open si e
du ing he s udy pe iod. Mean ± SD. Concen ación de oxíge-
no disuel o en la supe icie (línea con inua) y el ondo (línea
discon inua) del cen o du an e el pe íodo de es udio.
Limne ica 23(1-2) 11/10/04 10:04 Página 3
pH o he su ace wa e was always equal o o
highe han he pH o he bo om wa e (Table 1).
The laye o anoxic wa e in he open si e was
loca ed a 2-2.5 m deep in sp ing-summe . In con-
as , he bo om wa e a he li o al si e was a ely
anoxic (excep in Ma ch 2002).
The ligh compensa ion dep h in he open si e
anged om 0.7 o 2.3 m. Then, he a ailabili y
o PAR in he bo om wa e was always lowe
han 1% du ing he s udy pe iod. The ligh com-
pensa ion dep h was in e sely co ela ed wi h
he mean alue o chlo ophyll aconcen a ion in
he wa e column ( = -0.581, P<0.05) and also,
wi h bo h he mean alues o o al suspended
ma e and o ganic suspended ma e ( = -0.718,
= -0746, P<0.01, espec i ely). The concen a-
ion o plank onic chlo ophyll a anged om
74.2 o 330.7 µg l-1 in he su ace wa e and
om 34.8 o 256.2 µg l-1 in he bo om wa e
du ing he s udy pe iod (Table 1). The concen-
a ion o plank onic chlo ophyll awas signi i-
can ly highe in he su ace han in he bo om
wa e (Fig. 2) du ing June-Sep embe 2001 and
July-Augus 2002 ( -s uden , P<0.01).
The concen a ion o dissol ed ino ganic N ol-
lowed a seasonal pa e n, especially NO3-and
NO2-concen a ions ha dec eased in summe
and inc eased du ing ainy pe iods (Fig. 3). In
ac , he concen a ion o NO3-in he bo om
wa e was signi ican ly co ela ed o he amoun
o ain all collec ed be ween samplings
( =0.717, P<0.01). Also, bo h he NO2-concen-
a ion in he bo om and su ace wa e we e sig-
ni ican ly co ela ed o ain all ( =0.592 and
=0.604 P<0.05, espec i ely). In con as , he
concen a ion o o-P in he wa e , especially in
he bo om wa e , oscilla ed in pulses h oughou
he s udy pe iod (Fig. 4). The concen a ion o o-
P in he in e s i ial wa e o he sedimen also
peaked in e mi en ly and i was posi i ely co e-
la ed wi h he concen a ion o o-P in he bo -
om-wa e ( =0.698, P<0.05). The low a ailabili-
y o P and he high concen a ion o dissol ed
ino ganic ni ogen (DIN) de e mined ha he
a io o DIN/To -P was ela i ely la ge in bo h
he su ace and he bo om wa e (Table 1). In
con as , he a io N/P in he sedimen anged
om 0.05 o 4.34 du ing he s udy pe iod.
4Se ano e al.
Figu e 2. Concen a ion o plank onic chlo ophyll ain he
su ace (solid line) and bo om wa e (dashed line) a he open
si e du ing he s udy pe iod. Mean ± SD. Concen ación de
clo o ila aplanc ónica en la supe icie (línea con inua) y el
ondo (línea discon inua) del cen o du an e el pe íodo de
es udio.
Figu e 3. Concen a ion o NO3-in he su ace (solid line) and
bo om wa e (dashed line) a he open si e du ing he s udy
pe iod. Mean ± SD. Concen ación de NO3-en la supe icie
(línea con inua) y el ondo (línea discon inua) del cen o
du an e el pe íodo de es udio.
Limne ica 23(1-2) 11/10/04 10:04 Página 4
The concen a ion o To -P in he sedimen
anged om 120.3 o 964.3 µg gDW-1, and he
concen a ion o o ganic ma e anged om 0.9
o 13.5%. Bo h a iables we e highly co ela ed
( =0.853, P<0.01) sugges ing ha he sedimen
was ich in o ganic P-compounds. The P- ac-
iona ion o he sedimen showed ha he o gan-
ic P- ac ions comp ised 75% o he ine sedi-
men and 64 % o he o al sedimen (Table 2).
The la ges P- ac ion was always he one
ex ac ed wi h alkali (o g-Palkali), ollowed by
he acid soluble o ganic P- ac ion (o g-Pacid) in
he ine sedimen o he i on-bound ac ion
(Fe (OOH)~P) in he o al sedimen . The o g-
Pacid and he esidual o ganic ac ion (o g-
P esidual) we e highe in he ine sedimen ha in
he o al sedimen ( -s uden , P<0.01), whe eas
he Fe (OOH)~P and CaCO3~P we e highe in
he o al sedimen ( -s uden , P<0.01). These
di e ences can be explained by a lowe con en
o la ge de i al pa icles in he ine sedimen .
Fi y- i e axa o phy oplank on we e iden i-
ied du ing he s udy pe iod: 25 axa o
cyanobac e ia, 14 chlo ophy es, 4 dino lagela es,
10 dia oms, 3 c yp ophy es and 3 ch ysophy es
(Table 3). The phy oplank on densi y anged
om 2·104 o 7·106 cells ml-1. Two axa o
cyanobac e ia, Aphanocapsa holsa ica and
Mic ocys is sp., appea ed wi h an a e age ela i e
abundance o 35 % and 30 %, espec i ely. O he
axa such as C yp omonas sp., Amphidinium sp.,
Gymnodinium sp., Chae osce os sp., Oocys is sp.
and Pseudocho ella sp., eached an a e age ela-
i e abundance o only 2.5 – 4%. The mos com-
mon axa in all samplings (occu ence>60%)
we e Oscilla o ia sp., Oocys is sp., Oscilla o ia
limne ica, Ch oococcus sp. and Mono aphidium
ci cinale (Table 3). Consequen ly, he di e si y o
phy oplank on was e y low: an assemblage o
jus one, wo o h ee axa domina ed wi h a ela-
i e abundance >80% in mos o he samplings.
The seasonal phy oplank on succession was di -
e en in bo h yea s o s udy. In 2001, he blooms
o cyanobac e ia (Oscilla o ia sp., Mic ocys is
sp.,) al e na ed wi h a high densi y o dino lagel-
la es (Amphidinium sp., Gymnodinium sp.),
chlo ophy es (Oocys is sp., Mono aphidium sp.)
and dia oms (Chae oce os sp.). Howe e in 2002,
cyanobac e ia la gely domina ed o he mos pa
o he yea while he densi y o dino lagella es and
dia oms was g ea ly educed (Fig. 5).
The high wa e u bidi y hinde ed he g ow h
o subme sed aqua ic mac ophy es as only
Po amoge on pec ina us g ew in he shallowe
a eas, while he li o al ege a ion was mainly
Limnology o Ta elo Lagoon 5
Figu e 4. Concen a ion o o-P in he su ace (solid line) and
bo om wa e (dashed line) a he open si e du ing he s udy
pe iod. Mean ± SD. Concen ación de o-P en la supe icie
(línea con inua) y el ondo (línea discon inua) del cen o
du an e el pe íodo de es udio.
Table 2. Concen a ion o o-P (mg gDW-1) in he di e en P- ac ions o he ine sedimen (<0.1 mm) and he o al sedimen in May 2001.
Mean ± SD. Concen ación de o-P (mg gDW-1) en las dis in as acciones de P en el sedimen o ino y el sedimen o o al de mayo 2001.
Fe(OOH)~P CaCO3~P o g-Pacid o g-Palkali o g-P esidual
Fine sedimen 99±2.6 110±22.3 209±23.7 364±34.8 52±8.4
To al sedimen 123±11.8 222±8.5 101±3.3 495±30.6 22±4.9
Limne ica 23(1-2) 11/10/04 10:04 Página 5

composed o Ph agmi es aus alis and Typha
la i olia. A ew aqua ic in e eb a e species
we e eco ded du ing he s udy pe iod (Table 4).
Only 5 o i e species and 2 c us acean species
we e iden i ied in he zooplank on. The o al
densi y o he zooplank on gene ally anged
be ween 100 and 2000 ind l-1, bu popula ion
explosions we e common in o i e species such
as B achionus plica ilis (max. 2025 ind l-1) and
Ke a ella opica (max. 2118 ind l-1). The mini-
mum alue o zooplank on densi y (6 ind l-1)
was eco ded in June 2001 when he whole
wa e column became anoxic.
6Se ano e al.
Table 3. A e age ela i e abundance (F .) and occu ence (Occ.) o main phy oplank on species du ing he s udy pe iod. P omedio de la abun-
dancia ela i a (F ) y ecuencia de apa ición (Occ.) de las p incipales especies del i oplanc on.
Species F . (%) Occ. (%) Species F . (%) Occ. (%)
CYANOBACTERIA DIATOMS
Anabaena a . aspe a 0.1 13.6 Ampho a sp. 0.1 13.6
Anabaena a . spi oides 1.6 31.8 Cyclo ella meneghiniana 0.5 54.5
Anabaena aphanizomenoides 0.4 27.3 Cymbella sp. 0.1 4.5
Anabaena sp.1 0.1 13.6 Chae osce os sp. 3.9 45.4
Anabaena sp.2 0.1 9.1 F agilla ia a . cons uens <0.1 4.5
Anabaenopsis ci cula is 0.1 9.1 Melosi a sp. 0.1 9.1
Anabaenopsis sp. 0.1 4.5 Ni zschia palea 0.1 4.5
Aphanocapsa holsa ica 35.4 22.7 Ni zschia sp. 0.1 9.1
Aphanocapsa ince a 1.0 9.1 Uniden i ied penna e dia om 0.2 9.1
Caelosphae ium sp. 1.3 22.7 CHRYSOPHYTES
Calo h ix sp. 0.1 4.5 Mallomonas sp <0.1 4.5
Chl ogloea sp. 0.1 4.5 Och omonas sp. 0.1 18.2
Ch oococcus a . dispe sus 3.0 27.3 Uniden i ied ch ysophy a 0.1 4.5
Ch oococcus sp. 0.8 63.6 CHLOROPHYTES
Gomphosphae ia sp. 0.3 4.5 Ankis odesmus sp. 0.1 4.5
Lynbya sp. 0.1 18.2 Coelas um sp. 0.1 9.1
Me ismopedia sp. 0.1 9.1 Chlamydomonas sp. 0.1 4.5
Mic ocys is sp. 30.0 54.5 Chlo ella sp. 0.9 13.6
Oscilla o ia limne ica 1.4 63.6 Mono aphidium ci cinale 1.0 63.6
Oscilla o ia sp. 0.4 77.3 Mono aphidium con o um 0.3 36.4
Spi ulina sp. 0.1 18.2 Oocys is sp. 3.4 72.7
Synechococcus sp.0.1 13.6 Pando ina sp. 0.1 4.5
Synechocys is sp. 0.5 9.1 Pi amidomonas sp. <0.1 4.5
CRYTOPHYTES Pseudochlo ella sp. 3.1 4.5
C yp omonas sp.1 3.5 59.1 Scenedesmus sp. <0.1 4.5
C yp omonas sp.2 0.1 27.3 Sch oede ia sp. 0.1 40.9
Ch oomonas a . acu a 0.1 9.1 Uniden i ied Chlo ococcal 0.8 54.5
DINOFLAGELLATES Uniden i ied Vol ocal 0.1 9.1
Amphidinium sp. 3.2 40.9
Glenodinium sp.0.1 9.1
Gymnodinium sp. 2.6 50.0
Gymnodinium sp.2 0.1 9.1
Figu e 5. Changes in he ela i e abundance o phy oplank on
composi ion in he su ace a he open si e du ing he s udy
pe iod. Cambios en la abundancia ela i a de la composición
i oplanc ónica en la supe icie a lo la go del pe íodo de es u-
Limne ica 23(1-2) 11/10/04 10:04 Página 6
The ela i e abundance o Chi onomus plumo-
sus inc eased in au umn-win e (347-15000 ind
m-2 in he open-si e and 521-31900 ind m-2 in
he li o al si e) and dec eased in sp ing-summe
(0-140 ind m-2 in he open-si e and 0-1945 ind
m-2 in he li o al si e), eaching ze o du ing
June-July 2001 (open si e) and June-Augus
2002 (bo h li o al and open si es).
DISCUSSION
Due o i s a i icial o igin as an ex ac i e pi ,
he su ace basin o he lagoon is limi ed o i s
sho eline so i is basically ed by g ound wa e
and di ec ain all. The impo ance o g ound
wa e eeding is suppo ed by he inc ease in
conduc i i y du ing ainy pe iods. The salini y
o he i e bed aqui e o he Guadalqui i
Ri e is e y high in his a ea due o a ossil
aqui e below he es ua y (IGME, 1975) and o
he pa ial in usion o seawa e (Na a o
Al a gonzález e al., 1993). Addi ionally,
he high a io o Cl-: SO42-, and he ela ion o
Cl->SO42->CO3H-in hype haline wa e s is ypi-
cal o coas al lagoons (Alonso, 1998). Al hough
he su ace o he Ta elo lagoon is no connec ed
o he es ua y, seawa e can in luence he ionic
composi ion o he lagoon h ough bo h g ound
wa e seepage and sp ay.
The high concen a ions o bo h NO3-and
NO2-in he wa e and hei posi i e co ela ion
o ain all is also an indica ion o he impo ance
o g ound wa e eeding in his lagoon. The
g ound wa e o he Guadalqui i i e bed is
pollu ed wi h N as high NO3-concen a ions (ca.
8 mM) we e al eady de ec ed in his a ea in 1987
(Na a o Al a gonzález e al., 1993). The
amoun o NO3- eco ded in his lagoon (up o
20.3 mM) was e en la ge han ha ound in
he eu ophic lagoons o Ad a which ecei ed he
di ec inle o ag icul u al uno (Ca illo e al.,
1996). In con as , NO2- ended o be e y low
and NH4+was he dominan ino ganic o m o N
in o he aqua ic en i onmen s o he Doñana
a ea such as he empo a y ponds on aeolian
sand (Se ano & Toja, 1995). The load o NO3-
and NO2-du ing ainy pe iods declined ab up ly
du ing bo h summe s when NO3-concen a ion
eached ze o in he bo om wa e o his lagoon.
The o al concen a ion o DIN also dec eased
du ing bo h summe s and was minimal in June
2001. The e o e, DIN showed a seasonal pa e n
o en ichmen in au umn-win e due o g ound
wa e seepage, and o decline in summe due o
bo h deni i ica ion and NO3-assimila ion.
In spi e o he mixing c ea ed by he equen
coas al winds, signi ican di e ences be ween
he su ace and he bo om o he wa e column
we e de ec ed, pa icula ly in summe , in ela-
ion o se e al limnological a iables, such as
he concen a ion o phy oplank on, dissol ed
oxygen, pH, and suspended solids. Thus, bo h
he spa ial and empo al a iabili y o hose
a iables ela ed o he p ima y p oduc ion we e
coupled in a seasonal pa e n o e ical seg e-
ga ion. The ab up ex inc ion o he ligh pene-
a ion and he di e en a ailabili y o nu ien s
in he wa e column can accoun o his pa e n.
In con as o he seasonal pa e n o N, he
dynamics o P luc ua ed in pulses. The concen-
a ion o o-P in bo h he bo om wa e and he
in e s i ial wa e peaked du ing pe iods o anoxia
in he deep wa e . The e a e h ee hypo hesis o
explain he elease o o-P om anoxic sedi-
Limnology o Ta elo Lagoon 7
Table 4. Lis o aqua ic mic oin e eb a e species. Lis a de mic oin-
e eb ados acuá icos.
ROTIFERA
B achionus plica ilis
B. calyci lo us
B. no ae-zelandiae
Ke a ella opica
Tes udinella pa ina
CLADOCERA
Daphnia longispina
COPEPODA
Acan hocyclops c . kie e i
ISOPODA
Sphae oma se a um
GASTROPODA
Physella acu a
Po amopy gus an ipoda um
DIPTERA
Chi onomus plumosus
Limne ica 23(1-2) 11/10/04 10:04 Página 7
men s: h ough he educ ion o Fe(OOH)~P, he
acidi ica ion o sedimen s, and he mine aliza-
ion o o ganic P-compounds such as phy a e
(Gol e man e al., 1998). The decomposi ion o
o ganic ma e in he sedimen is a simple
mechanism o o-P elease ha canno be uled
ou (P ai ie e al.,2002), especially in his case,
when To -P and o ganic ma e in he sedimen
a e highly co ela ed. The concen a ion o To -P
in he sedimen o his lagoon ell wi hin he
ange o o he eu ophic shallow sys ems such as
he coas al lagoons o Ad a (De Vicen e e al.,
2003) and he Doñana empo a y ponds (Díaz-
Espejo e al., 1999). The majo i y o he To -P in
he sedimen o his lagoon was composed o
o ganic P- ac ions as in he case o he Doñana
ponds (Díaz-Espejo e al., 1999; Se ano e al.,
2000) whe e To -P and sedimen o ganic ma e
we e also co ela ed (Jaú egui & Toja, 1993).
The e o e, he eu ophic s a e o his lagoon
ensu ed a high in e nal P-loading as he concen-
a ion o plank onic chlo ophyll ain he wa e
column a e aged 137.5 µg l-1 du ing he s udy
pe iod. An e en highe concen a ion o chlo o-
phyll ahas been eco ded in he hype eu ophic
coas al lagoon Albu e a o Valencia (200-600
µg l-1) ha was also domina ed by cyanobac e ia
(Vicen e & Mi acle, 1992).
The a iabili y o he local wind speed can
also gene a e pulse-scale e en s ha may p o-
duce a signi ican e ec on he unc ioning o
he sys em unde he p esen condi ions o high
phy oplank on p oduc ion. This is he case o an
episode o anoxia, on 12 h June 2001, ha
deple ed he en i e wa e column o dissol ed
oxygen a e a pe iod o in e mi en mixing
gene a ed by an al e na ion o s ong winds and
calms. Du ing in e mi en mixing, cyanobac e-
ia, such as Mic ocys is colonies, mig a e
upwa d b inging abou he de elopmen o
blooms (Eas hope & Howa d, 1999). In ac ,
Mic ocys is bloomed in his lagoon in May
2001 esul ing in he minimum alue o ligh
pene a ion in 2001 and he highes alue o o -
P in he pa icula e suspended ma e ial o bo h
he su ace and he bo om wa e . One mon h
la e , he episodic anoxia ook place and he
wa e column became dis inc ly seg ega ed in
wo laye s: a su ace laye wi h mo e chlo o-
phyll aand less o-P han he bo om laye . The
a ailabili y o nu ien s in a dim ligh en i on-
men could ha e a ou ed he la e g ow h o
Oscilla o ia. I is well known he abili y o
cyanobac e ia o al e na e be ween au o ophic
and he e o ophic me abolisms and, in pa icu-
la o Oscilla o ia limne ica, o al e na e
be ween oxygenic and a non-oxygenic pho o-
syn hesis when he sulphide concen a ion is
high and he a ailable PAR is low (A las &
Ba ha, 1998). Some algal species a e also able
o u n o a he e o ophic me abolism when
ligh a ailabili y is e y low and he e is a high
pool o dissol ed o ganic compounds de i ed
om he dying cells (Tuchman, 1996; So okin,
1999). Tha is he case o he dino lagella e
Gymnodinium and he dia om Chae oce os ha
bloomed in July and Augus 2001, espec i ely.
In he long un, cyanobac e ia a e known o
domina e he phy oplank on communi y in
eu ophic sys ems due o he many ad an ages
hey can exhibi unde luc ua ing condi ions,
such as hei me abolic e sa ili y, hei gas
esicles, hei nu ien up ake a e y low o-P
concen a ion and hei capaci y o h i e in
educing condi ions (So okin, 1999). In his
lagoon, he in e mi en mixing, he di e en
ime-scales o nu ien a ailabili y, he a iabili-
y o he unde wa e ligh en i onmen and o
he educing condi ions, c ea ed a luc ua ing
en i onmen mos sui able o cyanobac e ia.
As i can be expec ed in eu ophic sys ems
unde s ess, he numbe o axa was ela i ely
low and he communi ies we e domina ed
by only a ew species. Simila ly, mo e han
80% o he o al phy oplank on biomass was
comp ised by no mo e han h ee species du -
ing mos pa o he yea in he hype eu ophic
lagoon Albu e a o Valencia (Romo & Mi acle,
1995). E en an oppo unis ic species, such as
Chi onomus plumosus, common in eu ophic
en i onmen s (P a , 1991) disappea ed om
he sedimen su ace du ing summe . Simila ly,
an indica o o bo h eu ophic and mine alised
wa e s such as Po amoge on pec ina us
8Se ano e al.
Limne ica 23(1-2) 11/10/04 10:04 Página 8
(Sche e , 1998) was e y sca ce and es ic ed
o he shallowe a eas.
Al hough he s udy pe iod was o sho o
d aw any endency, he e we e some indica-
ions o a quick p og ess owa ds an e en high-
e ophic deg ee: he concen a ion o bo h
o al and o ganic suspended ma e inc eased
in 2002 wi h espec o 2001 and he a e age
summe chlo ophyll was also highe in 2002 as
well as he ela i e abundance o cyanobac e-
ia. A endency owa ds a mo e ad anced s age
o eu ophica ion is quie likely as eu ophic
en i onmen s domina ed by cyanobac e ia can
c ea e a sel - egula ed sys em o main ain s a-
ble blooms in lakes (Sakamo o & Okino, 2000;
Gibson e al., 2000). Howe e in he con ex o
coas al lagoons, ansi ional s ages can also
lead o uns able si ua ions (Comín e al.,
1999). A e yea s wi hou appa en changes,
ca as ophic shi s ha e d as ically changed he
aqua ic communi ies o he coas al lagoon
Albu e a o Valencia (Vicen e & Mi acle,
1992). The coas al lagoons o Comacchio
(I aly) ha e eached a p eca ious equilib ium
unde he absolu e dominance o cyanobac e ia
wi h he al e na ion o au o ophic and he e-
o ophic s ages when he aqua ic auna c ash-
es o unde ec able numbe s du ing dys ophic
c isis (So okin, 1999). The e o e, as p ima y
p oduc ion inc eases in he lagoon o Ta elo,
he ood a ailable o he Whi e-headed duck
(Oxyu a leucocephala) will likely dec ease as
his species eeds mainly on chi onomids, and
seconda y on aqua ic subme sed mac ophy es
(G een e al., 1999).
ACKNOWLEDGEMENTS
We hank Jose Ma ia A ana o his help and
pa ience, and Luis Rod iguez “Fon” o his col-
labo a ion. We a e also hank ul o he ange s
o he Doñana Na u al Pa k, o S a. Lola and he
amily, o he people o Ven a El Raspa and
Casa Ru al La Algaida. The Conseje ía de
Medio Ambien e, Jun a De Andalucía, suppo -
ed his p ojec .
REFERENCES
ALONSO, M. 1998. Las lagunas de la España penin-
sula . Limne ica, 15: 1-176.
APHA. 1985. S anda d me hods o he examina ion
o wa e and was ewa e . 16 h ed. Ame ican Public
Heal h Associa ion.
ATLAS, R. M. & R. BARTHA. 1998. Mic obial
Ecology. Fundamen als and applica ions.
Benjamin/Cummings Publishing Company, Inc.
Menlo Pa k, 694 pp.
CARRILLO, P., P. SÁNCHEZ-CASTILLO, L.
CRUZ-PIZARRO & R. MORALES. 1996.
Cambios cíclicos y endencias a la go plazo en la
salinización de ecosis emas luc uan es (Albu e as
de Ad a). E idencias de eu o ización y con ami-
nación. Limne ica, 12: 59-65.
COMÍN, F. A, F. MENÉNDEZ, J. A. ROMERO, O.
HERNÁNDEZ, M. MARTÍNEZ & A. CHACÓN.
1999. Indicado es ecológicos y he amien as
pa a la ges ión de ecosis emas acuá icos en la
zona cos e a. Limne ica, 16: 61-68.
DE GROOT, K. J. & H. L. GOLTERMAN. 1990.
Sequen ial ac iona ion o sedimen phospha e.
Hyd obiologia, 192: 143-149.
DE VICENTE, I., L. SERRANO, V. AMORES, V.
CLAVERO & L. CRUZ-PIZARRO. 2003.
Sedimen phospha e ac iona ion and in e s i ial
wa e phospha e concen a ion in wo coas al
lagoons (Albu e as de Ad a, SE Spain).
Hyd obiologia, 492: 95-101.
DÍAZ-ESPEJO, A., L. SERRANO & J. TOJA. 1999.
Changes in sedimen phospha e composi ion o
seasonal ponds du ing illing. Hyd obiologia,
392: 21-28.
GIBSON, C. E., R. H. FOY & S. D. LENNOX. 2002.
The ise and ise o Plank o h ix aga dhii in
Lough Neagh 1969-1997. Ve h. In e na . Ve ein.
Limnol., 27: 2913-2916.
GREEN, A. J., A. D. FOX, B. HUGHES & G. M.
HILTON. 1999. Time-ac i i y budge s and si e
selec ion o Whi e-headed Ducks Oxyu a leuco-
cephala a Bu du Lake, Tu key in la e win e .
Bi d S udy, 46: 62-73.
GOLTERMAN, H. L. 1991. Di ec nessle iza ion o
ammonia and ni a e in esh-wa e . Annls
Limnol., 27: 99-101.
GOLTERMAN, H. L. 1996. F ac iona ion o sedi-
men phospha e wi h chela ing compounds: a sim-
pli ica ion, and compa ison wi h o he me hods.
Hyd obiologia, 335: 87-95.
Limnology o Ta elo Lagoon 9
Limne ica 23(1-2) 11/10/04 10:04 Página 9