Impact of water salinity on Odontesthes bonariensis (Actinopterygii, Atherinopsidae) fisheries in Chasicó Lake (Argentina)

Abstract

Odontesthes bonariensis is an inland water fish from the Pampas region, valued due to the quality of its flesh and its attractiveness as a game fish. Chasico´ Lake located in the south of the pampean region is appreciated by fishermen due to O. bonariensis abundance. However, in the last year, a reduction in their catches was recorded. In this work, it was analyzed the changes of O. bonariensis biomass in relation to climate change and salinity in Chasico´ Lake from 1997 to 2013. From 2004 to 2013, when a dry period began, a reduction in lake area (68.1?47.4 km2) and an increase in salinity (18.9?41.5 g l-1) were observed. O. bonariensis catches showed a significant decrease in the same period as a result of salinity increments. Possibly, at high salinity, O. bonariensis may still develop but with an impaired reproduction and limited embryo and juvenile survival. In conclusion, after 2004, the fishery quality in Chasico´ Lake showed a decreasing trend from the maximum registered in the Pampas lakes. This was in agreement with a marked decrease in the lake area which in turn increased water salinity up to levels close to the O. bonariensis tolerance limit.