Temporal dynamics of fish community in the lower portion of a tidal creek (Pando estuarine system, Uruguay)

Rodrigo Gurdek Bas, Alicia Acuña-Plavan


Estuaries are highly dynamic ecosystems subjected to variability of their fish communities over different time scales. Given this, the nearshore fish community of the lower Pando estuary, a temperate sub-system of the Río de la Plata estuary, was sampled on a monthly basis from May 2002 to June 2003, increasing sampling effort to 24 h during each season of the year. A total of 2,165 fish, represented by 16 species were caught by seine netting over the study period. Captures were largely dominated by juveniles (>90%), as well as by the sciaenid Micropogonias furnieri (Desmarest, 1823) (82.8%). In general terms, fish community showed seasonal and diel changes in terms of ichthyofaunal composition, abundance, species richness and diversity. Greatest average values of species richness (4/ 300m2) and diversity (0.72/ 300m2) occurred during summer, while highest average values of biomass (4,532.3g/ 1000m2) during spring. Diel variance was detected for the species M. furnieri, Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874), Odontesthes argentinensis (Valenciennes, 1835) and Brevoortia aurea (Spix & Agassiz, 1829). Variability was attributed to life cycle, environmental interaction and feeding activity of fish species, as well as to photoperiod. Sub-estuarine systems deserve further attention as they are ecologically important, mainly as transitional and permanent fish habitats.

Iheringia Série Zoologia

Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul

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