Salinity tolerance and fishing performance of Odontesthes bonariensis (Actinopterygii; Atherinopsidae) in a shallow lake of Argentina
The silverside (Odontesthes bonariensis) is the most important species in Argentine fisheries due to its wide distribution, great demand and supply of fish protein. This species shows a great ecological plasticity; however, there is little research describing its tolerance to salinity in natural conditions. Dam constructions for irrigation, hydroelectric generation and human consumption, in synergy with glacial retraction, cause great instability in certain wetlands located downstream. In Curacó chained lakes, in the Desaguadero basin (La Pampa, Argentina), the environments reach high salinity and can even dry out entirely. During the period 2004-2008, a significant increase in water flows in this region modified its chemical characteristics and favored the development of silverside. In October 2009, water stopped entering into the system and, in 2011, many lakes disappeared. The objective of this work was to analyze the survival and fishing yield of O. bonariensis in a context of environmental tolerance due to the gradual surface decrease and the increase of salts concentration in La Brava shallow lake (37°55’24’’ S - 65°55’18’’ W). Water salinity increased progressively from 7.05 to 59.3 g/L and O. bonariensis was present up to a concentration of 49.9 g/L. Fish size evidenced a virgin population with specimens up to 482 mm of LEst and 7 years of age. High catches per unit of effort (CPUE) in number and biomass were observed, with maximums of 375 fish and 204. 6 kg/night, but these did not exhibit a strong linear correlation with saline concentration. The salinity tolerance observed in O. bonariensis is higher than that reported by other authors and places this freshwater fish among the most euryhaline in the world.
| Main Authors: | , |
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| Format: | Digital revista |
| Language: | spa |
| Published: |
Asociación Argentina de Ecología
2022
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| Online Access: | https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/1898 |
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