Fish assemblages of Castro Marim salt
marsh
Pedro Veiga, Constança Bexiga, Lina Vieira1, Rita Sá1 & Karim Erzini1
1 CCMAR/FCMA, Universidade
do Algarve, Campus de Gambelas, 8000-117 Faro, Portugal. Corresponding author: [email protected].
INTRODUCTION
Castro Marim salt marsh is a wetland located in the southeast part of the Algarve, adjacent to the mouth of the Guadiana river. It is classified as a protected area since
1975, mainly due to its importance as a breeding area for birds. Although salt marshes are known to be very productive ecosystems and important nursery areas for
many species (Kneib, 1997), fish communities using salt marshes have rarely been studied in Europe (Laffaille et al., 2000), with few studies in Castro Marim salt
marsh (e.g. Machado, 1978; Gonçalves and Beldade, 2000). The present work focused on the structure and dynamics of the fish assemblages of Castro Marim salt
marsh.
h
MATERIAL AND METHODS
Sampling was conducted monthly at five sampling sites (A and B:
Lezíria creek; C and D: Carrasqueira creek; E: outer adjacent area of
salt marsh) (Figure 1), from September 2000 to August 2001. Samples
were taken at night during rising neap tides using a 40 m long beach
seine (Figure 2), In the laboratory, fishes were identified, counted,
measured
d (total
(t t l length
l
th to
t the
th nearestt millimetre)
illi t ) and
d weighed
i h d (wet
( t
weight with 0.001g precision).
Relative abundances and weight were determined for each fish species
and total mean abundances and species richness were determined per
month.
Figure 1- Location of Castro Marim salt marsh and
sampling sites. Source: RNSCMVRSA (2002).
An ecological guild, adapted from Mathieson et al. (2000) and based on
the occurrence, distribution and abundance of fish in the present study,
was attributed to each fish species: resident (R); Marine juvenile
migrants (“nursery” species) (MJ); marine adventitious visitors (MA);
diadromous (catadromous (CA)/anadromous(AN)) migrants and
freshwater adventitious visitors (FW).
RESULTS AND DISCUSSION
A total of 7955 fish specimens (37995,7g), comprising 34 species and 17 families were
sampled (Table I). Fish composition is similar to those found in other salt marshes,
estuaries and coastal lagoons in Portugal and Europe (Mathieson et al., 2000). Most of
the species in this study were marine adventitious visitors or marine juvenile migrants,
being present only in some periods of the year. However, the resident species
Pomatoschistus microps (51.9%) and Atherina spp. (10.3%) dominated the fish fauna,
together accounting for 60.2% of total abundance.
Unlike other studies (e.g. Ambrose and Meffert, 1999; Lazzari et al., 1999), abundance
did not show a clear seasonal pattern (Figure 3A), as seen for species richness (Figure
3B). Temporal variations in mean abundance reflected fluctuations in the dominant
species. Jackson and Jones (1999) suggested that the consistent presence of many of
the dominant species masks the influence of any monthly immigrations and emigrations.
emigrations
Table I- Species ecological guilds (EG), percentage in number (%N) and Weight (%W),
length range and percentage of juveniles, for the fish species caught in Castro Maim salt
marsh from September 2000 to August 2001.
EG
%N
%W
R
R
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MA
MJ
R
MA
MJ
R
MA
AN
CA
MA
AN
FW
MA
FW
MA
MA
R
MA
MA
MA
MA
51,9
10,3
6,6
6,6
5,4
4,3
3,9
2,9
2,4
1,5
1,0
0,6
0,5
0,3
0,3
03
0,3
0,3
0,2
0,2
0,1
0,1
0,1
0,1
0,1
0,0
0,0
0,0
0,0
0,0
00
0,0
0,0
0,0
0,0
7955
5,8
7,8
4,1
13,4
3,9
9,4
15,9
13,5
0,5
4,6
2,3
1,1
1,4
1,7
0,5
04
0,4
0,2
0,0
0,3
0,2
0,6
2,1
0,1
9,7
0,0
0,0
0,0
0,1
0,0
03
0,3
0,0
0,0
0,2
37995,7
Length range (cm) % JUV
2,0-6,0
3,95-12,3
2,4-6
6,0-19,6
2,7-10,7
4,1-11,7
6,0-39,7
5,0-15,8
3,8-9,0
6,4-22,5
5,2-17,2
4,0-10,7
2,05-20,8
7,1-22,3
6-9,95
8 4 11 7
8,4-11,7
4,1-8,2
2,5-5,9
7,0-9,8
8,95-13
3,1-32,9
36,3-68,2
9,9-11
44,1-46,3
9,4-9,7
5,5-7,9
8,2
3,2
18,55
61
6,1
23
7,3
11,9
2,2
100
100
100
100
96,9
100
100
98,3
100
100
100
100
18,5
15
100
77,8
100
24,0
100
0
100
100
100
-
The majority of species were represented mostly by juveniles, emphasising the nursery
function of this ecosystem, as suggested by various authors for other salt marshes (e.g.
Lazzari et al. 1999; Mathieson, 2000).
Castro Marim salt marsh constitutes an important ecosystem for fishes, since it provides
habitat for many species, mostly juveniles, which find here suitable conditions for their
development.
catch per haul (nu
umber)
Species
Pomatoschistus microps
Atherina spp.
Mugilidae n.id.
Liza aurata
Diplodus sargus
Spondyliosoma cantharus
Liza ramada
Mullus surmuletus
Sardina pilchardus
Liza saliens
Dicentrarchus labrax
Diplodus vulgaris
Halobatrachus didactylus
Chelon labrosus
Gobius niger
E
Engraulis
li encrasicolus
i l
Diplodus bellottii
Pomatoschistus minutus
Mullus barbatus
Alosa alosa
Anguilla anguilla
Belone belone
Alosa fallax
Cyprinus carpio
Syngnathus acus
Tinca tinca
Dicentrarchus punctatus
Diplodus annularis
Fundulus heteroclitus
Mugil cephalus
Parablennius gattorugine
Pomatomus saltatrix
Solea senegalensis
Total
700
600
500
400
300
200
100
0
species per haul (n
number)
The proportion of juveniles was determined based on length at maturity
reported for the species (Cabral et al. (2000).
Figure 2- Beach seine used in the present
study to sample the fish.
A
Set Nov Jan Fev Mar Abr Mai Jun Jul Ago
month
20
15
B
10
5
0
Set Nov Jan Fev Mar Abr Mai Jun
Jul Ago
month
Figure 3- Monthly variations in mean (+ SD) abundance (A) and species richness (B) in Castro Marim salt marsh, from
September 2000 to August 2001.
REFERENCES::
REFERENCES
Ambrose, R.F. & Meffert, D.J. 1999. Fish-assemblage dynamics in Malibu lagoon, a small, hydrologically altered estuary in southern California. Wetlands, 19: 327-340.
Cabral, H.N.; Duque, J. and Costa, M.J. 2000. Importance of the coastal zone adjacent to the Tagus estuary as a nursery area for fish. Thalassas, 16: 27-32.
Gonçalves, E. and Beldade, R. 2000. Avaliação do Estado de Conhecimento e Inventariação das Comunidades Ictiológicas da Reserva Natural do Sapal de Castro Marim e
Vila Real de Santo António. Relatório Final- ISPA, ICN, RNSCMVRSA. Lisboa. 26 p.
Kneib, R.T. 1997. The Role of tidal marshes in the ecology of estuarine nekton. Oceanography and Marine Biology: an Anual Review, 35: 163-220.
Laffaille, P.; Feunteun, E. and Lefeuvre, J.C. 2000. Composition of fish communities in a European macrotidal salt marsh (the Mont Saint-Michel Bay, France). Estuarine,
Coastal and Shelf Science, 51: 429-438.
ACKNOWLEDGEMENTS
Lazzari, M.A.; Sherman, S.; Brown, C.S.; King, J.; Joule, B.J.; Chenoweth, S.B. & Langton, R.W. 1999. Seasonal and annual variations in abundance and species
composition of two nearshore fish communities in Maine. Estuaries, 22: 636-647.
Machado, F.G. 1978. Acerca dum novo reconhecimento ictiológico efectuado na Reserva do Sapal de Castro Marim. Natureza e Paisagem, 4: 29-25.
We thank LNEC for financing this work, part of the project “Estudo das condições ambientais
no estuário do rio Guadiana e zonas adjacentes”.
Mathieson, S.; Cattrijsse, A.; Costa, M.J.; Drake, P.; Elliott, M.; Gardner, J. & Marchand, J. 2000. Fish assemblages of European tidal marshes; a comparison based on
species, families and functional guilds. Marine Ecology Progress Series, 204: 225-242.