Effect of water quality on growth of four fish spe

Authors: Esther López Siangas Marc Pouilly Adamit Vallejos Tamara Pérez Danny Rejas

Publish Date: 2012/05/05

Volume: 95, Issue: 3, Pages: 371-381

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Abstract

Fish growth is an indicator of populations’ life conditions that could be used to detect stress due to contamination In this study age of fishes of four species Psectrogaster essequibensis Schizodon fasciatus Triportheus angulatus and Pygocentrus nattereri from the Iténez basin Upper Madera Amazon were estimated by otolith readings and growth parameters were estimated by using the Von Bertalanffy Growth Function Populations of four sites were compared in order to detect the effect of natural and anthropogenical water chemistry differences One of these sites was directly impacted by gold mining activities whereas the three others were only influenced by mild human activities and presented white or clear waters Species growth coefficient K varied from 028 P nattereri to 039 P essequibensis 069 S fasciatus and 171 T angulatus Due to the limited size samples these values have to be considered as preliminary regional approximation For S fasciatus P nattereri and T angulatus residuals analysis of the growth function showed differences among the three unimpacted sites However each species exhibited different patterns of growth variations among sites thus preventing to clearly demonstrate a general effect of water chemistry on the fish growth of these populations On the contrary for these three species fish growth appeared weaker in the goldmining siteThis work was part of the IRD funded project “Trophic Ecology of Amazonian Aquatic Systems” JEAIEMAA received supports from IRDUR131 and WWF Bolivia funded project KN10 WWFIRD agreement and logistical support of Iténez departmental park PDAMNI Iténez and Beni Prefecture We would like to thank WWFTrinidad team and all the people who helped in the field work especially the fishermen and boat pilots Hermogenes Ribero Rodriguez Tomas Suarez José Vasquez and their families We are also grateful for the warm welcome in the Iténez communities of Bella Vista Remanso Mategua and Versalles We are grateful to Jesus Nuñez IRD to helpful comments and Tarik Meziane MNHN Paris for style correction

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