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Vol. 51 No. 3, 2012
Responses of Copepoda Life-History Stages to Climatic Variability in a Southern-European Temperate Estuary
Ana M.M. Gonçalves1,*, Miguel Â. Pardal1, Sónia C. Marques1, Susana Mendes2,3, María J. Fernández-Gómez3, María P. Galindo-Villardón3, and Ulisses M. Azeiteiro1,4
1Centre
for Functional Ecology (CFE), Department of Life Sciences, University
of Coimbra, Apartado 3046,3001-401 Coimbra, Portugal
2GIRM-Marine Resources Research Group, School of
Tourism and Maritime Technology, Polytechnic Institute of Leiria,
Campus 4, 2520-641 Peniche, Portugal
3Department of Statistics, University of Salamanca,37007 Salamanca, Spain
4Department of Sciences and Technology, Universidade Aberta, 4200-055Porto, Portugal
Ana
M.M. Gonçalves, Miguel Â. Pardal, Sónia C. Marques, Susana Mendes,
María J. Fernández-Gómez, María P. Galindo-Villardón, and Ulisses M.
Azeiteiro (2012) In
this study, we investigated the effects of an extreme climate event
(severe drought) on copepod ecology. Monthly sampling events were
conducted from 2005 to 2007, at 5 stations, using 63- and 335-µm-mesh
nets in Mondego Estuary, Portugal. The Calanoida were represented
mainly by Acartia clausi, Temora longicornis, and A. tonsa and the Cyclopoida by Oithona plumifera and Acanthocyclops robustus. Acartia clausi and T. longicornis dominated at the mouth and middle estuary; A. tonsa and A. robustus were associated with the upper estuary while O. plumifera
showed the highest densities in the downstream section. Nauplii
occurred in higher densities at the mouth. Relationships of copepod
assemblages and environmental factors were analyzed using the STATICO
method which allowed us to distinguish the combination of factors that
most contributed to these relationships. Winter was characterized by
high concentrations of nutrients, cold waters, and low salinities,
while summer was generally characterized by high values of phosphate,
salinity, and temperature. Marine and estuarine species (mainly
copepodites) showed high densities in summer. Freshwater species
occurred at maximal densities in winter, coincidently with higher river
flow. Copepod assemblages showed a clear seasonal pattern that was
superimposed on the interannual variability. Moreover, a severe drought
was responsible for the dominance of marine species.
Key words: Copepods, Life stages, Mondego Estuary, Seasonal and interannual variability, STATICO.
*Correspondence: Tel: 35-12-39836386. Fax: 35-12-39823603. E-mail:ammendes@student.zoo.uc.pt; anamartagoncalves@ua.pt
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