Environmental Changes on Freshwater Fish Communities in South America in the last five decades: A Case Study in Northeast Argentina

A.V. VOLPEDO.; THOMPSON GA

Sustainability, Agri, Food and Environmental Research

Universidad Católica de Temuco

Lugar: Santiago de CHILE; Año: 2016 vol. 4 p. 44 - 59

0719-3726

Environmental changes together withother stressors, such as habitat destruction, may cause widespread extinctions,decrease in biodiversity and disrupt natural communities, resulting in novelspecies assemblages. South America has a large diversity of freshwater fishwith complex evolutionary histories, mainly due to the presence of a widevariety of aquatic environments. Argentina has experienced an increase inrainfall in the last five decades leading to important climatic andhydrological changes. These changes caused the displacement of the isohyetstowards the west. This study reports changes in the composition of freshwaterfish in northeast Argentina during the last five decades, and investigated acausal relationship between the variation in fish assemblages and climatechange.The changes in the distribution andcomposition of fish communities between 1962 and 2010 were analyzed in 22stations. These stations were grouped in relation to the ichthyogeographicprovinces: Great Rivers province (GRp) and Pampean province (Pp). Thecorrelation between rainfall in relation to the number of total species from eachof the studied provinces showed a significant positive correlation in Pp andnot correlation in GRp. The annual mean river discharge and the number of totalspecies from each ecoregion showed a significant positive correlation in GRp,and not correlation in Pp. The results of this study strongly suggest that therainfall variations and river discharges observed in northeast Argentinainduced changes in the composition of fish assemblages that lead to theredistribution of fish species among ichthyogeographic provinces.