Fish assemblage of a Pampean shallow lake, a story of instability

COLAUTTI DARÍO; BAIGUN, CLAUDIO; LLOMPART FACUNDO; MAIZTEGUI TOMÁS; GARCÍA DE SOUZA JAVIER; SOLIMANO, PATRICIO; BALBONI LEANDRO; BERASAIN GUSTAVO

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2014

0018-8158

Pampean lakes are characterised by the alteration of flood and drought periods which, in turn, influence the biotic communities; however, little is known about its effects on fish assemblage in an extended temporal scale. The aim of this work was to analyse the temporal variability of the fish assemblage in Chascomús Lake, the most studied shallow lake of the Pampean region, and to discuss the role of climatic variables as potential drivers of fish composition shifts. Data acquisition was based on experimental fishing performed from 1999 to 2013 and from historical fishing records. Two alternative fish assemblage configurations were identified by cluster analysis. Odontesthes bonariensis, Parapimelodus valenciennis and Cyphocharax voga were the dominant species, which accounted for 70-80% of the relative abundance. O. bonariensis showed temporal fluctuations in its representativeness, changing from dominant to almost absent. C voga and P. valenciennis changed their abundance following a similar pattern along time. When historical data were considered, Platanichthys platana appeared as the fourth most dominant species. Precipitation, critical temperatures and fish mortalities were identified as the main drivers of species abundance shifts. This study highlights the importance of long-term assessments to maintain or restore natural ecological processes and fisheries in Pampean shallow lakes.