Mercury concentrations and differences in isotopic niches of fish from upstream and downstream of an Amazon reservoir dam.

Autor: de Castro Paiva T; Instituto de Biofísica Carlos Chagas Filho, Laboratório de Estudos Ambientais Olaf Malm, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-900, Brasil. thaisdecp@gmail.com.; Instituto de Ciências Biológicas, Laboratório de Limnologia, Ecotoxicologia e Ecologia Aquática, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brasil. thaisdecp@gmail.com., Pestana IA; Instituto de Química, Departamento de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, 24020-141, Brasil.; Grupo de Pesquisa em Biogeoquímica de Ecossistemas Aquáticos, Laboratório de Ciências Ambientais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brasil., de Oliveira BCV; Grupo de Pesquisa em Biogeoquímica de Ecossistemas Aquáticos, Laboratório de Ciências Ambientais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brasil., de Almeida MG; Grupo de Pesquisa em Biogeoquímica de Ecossistemas Aquáticos, Laboratório de Ciências Ambientais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brasil., Malm O; Instituto de Biofísica Carlos Chagas Filho, Laboratório de Estudos Ambientais Olaf Malm, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-900, Brasil., de Rezende CE; Grupo de Pesquisa em Biogeoquímica de Ecossistemas Aquáticos, Laboratório de Ciências Ambientais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brasil., Kasper D; Instituto de Ciências Biológicas, Laboratório de Limnologia, Ecotoxicologia e Ecologia Aquática, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brasil.
Jazyk: angličtina
Zdroj: Ecotoxicology (London, England) [Ecotoxicology] 2024 Sep; Vol. 33 (7), pp. 762-771. Date of Electronic Publication: 2024 Jul 10.
DOI: 10.1007/s10646-024-02776-6
Abstrakt: Reservoir construction promotes many environmental impacts, including the enhancement of mercury concentrations in fish. The processes that can influence mercury concentrations in fish in Amazonian reservoirs are still little explored in depth, especially when we consider the possible particularities of the ecosystems in question. This study aims to investigate how mercury concentrations in fish could be influenced by the Tucuruí dam, considering possible changes in their feeding and trophic position according to the dam position (up or downstream). Fish were sampled upstream and downstream of the Tucuruí reservoir, and total mercury (THg) and stable isotopes of carbon and nitrogen (δ 15 N and δ 13 C) were measured in muscles. We observed three different Hg bioaccumulation patterns influenced by the dam. These differences occurred due to species trophic niche changes corroborated by the isotope analysis. Higher THg concentrations downstream compared to those upstream ones were only observed for Geophagus proximus. On the contrary, Plagioscion squamosissimus, from downstream, presented lower concentrations than upstream ones. The isotopic niche of these two species presented different changes according to the sampled site. THg biomagnification was higher upstream compared to downstream, considering that the regression slope was approximately two times higher upstream versus downstream. THg concentrations in fish were explained by the differences in their feeding habits according to their location in relation to the dam. The difference in THg biomagnification was able to reflect differences in structure of the food web chain in ecosystems under the dam's influence.
(© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
Databáze: MEDLINE
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