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Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia

We examined mercury concentrations in three fish assemblages to estimate biomagnification rates in the Iténez main river, affected by anthropogenic activities, and two unperturbed rivers from the Iténez basin, Bolivian Amazon. Rivers presented low to moderate water mercury concentrations (from 1.25...

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Autores principales: Pouilly, Marc, Rejas, Danny, Pérez, Tamara, Duprey, Jean-Louis, Molina, Carlos I., Hubas, Cédric, Guimarães, Jean-Remy D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669100/
https://www.ncbi.nlm.nih.gov/pubmed/23741452
http://dx.doi.org/10.1371/journal.pone.0065054
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author Pouilly, Marc
Rejas, Danny
Pérez, Tamara
Duprey, Jean-Louis
Molina, Carlos I.
Hubas, Cédric
Guimarães, Jean-Remy D.
author_facet Pouilly, Marc
Rejas, Danny
Pérez, Tamara
Duprey, Jean-Louis
Molina, Carlos I.
Hubas, Cédric
Guimarães, Jean-Remy D.
author_sort Pouilly, Marc
collection PubMed
description We examined mercury concentrations in three fish assemblages to estimate biomagnification rates in the Iténez main river, affected by anthropogenic activities, and two unperturbed rivers from the Iténez basin, Bolivian Amazon. Rivers presented low to moderate water mercury concentrations (from 1.25 ng L(−1) to 2.96 ng L(−1)) and natural differences in terms of sediment load. Mercury biomagnification rates were confronted to trophic structure depicted by carbon and nitrogen stable isotopes composition (δ(15)N; δ(13)C) of primary trophic sources, invertebrates and fishes. Results showed a slight fish contamination in the Iténez River compared to the unperturbed rivers, with higher mercury concentrations in piscivore species (0.15 µg g(−1) vs. 0.11 µg g(−1) in the unperturbed rivers) and a higher biomagnification rate. Trophic structure analysis showed that the higher biomagnification rate in the Iténez River could not be attributed to a longer food chain. Nevertheless, it revealed for the Iténez River a higher contribution of periphyton to the diet of the primary consumers fish species; and more negative δ(13)C values for primary trophic sources, invertebrates and fishes that could indicate a higher contribution of methanotrophic bacteria. These two factors may enhance methylation and methyl mercury transfer in the food web and thus, alternatively or complementarily to the impact of the anthropogenic activities, may explain mercury differences observed in fishes from the Iténez River in comparison to the two other rivers.
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spelling pubmed-36691002013-06-05 Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia Pouilly, Marc Rejas, Danny Pérez, Tamara Duprey, Jean-Louis Molina, Carlos I. Hubas, Cédric Guimarães, Jean-Remy D. PLoS One Research Article We examined mercury concentrations in three fish assemblages to estimate biomagnification rates in the Iténez main river, affected by anthropogenic activities, and two unperturbed rivers from the Iténez basin, Bolivian Amazon. Rivers presented low to moderate water mercury concentrations (from 1.25 ng L(−1) to 2.96 ng L(−1)) and natural differences in terms of sediment load. Mercury biomagnification rates were confronted to trophic structure depicted by carbon and nitrogen stable isotopes composition (δ(15)N; δ(13)C) of primary trophic sources, invertebrates and fishes. Results showed a slight fish contamination in the Iténez River compared to the unperturbed rivers, with higher mercury concentrations in piscivore species (0.15 µg g(−1) vs. 0.11 µg g(−1) in the unperturbed rivers) and a higher biomagnification rate. Trophic structure analysis showed that the higher biomagnification rate in the Iténez River could not be attributed to a longer food chain. Nevertheless, it revealed for the Iténez River a higher contribution of periphyton to the diet of the primary consumers fish species; and more negative δ(13)C values for primary trophic sources, invertebrates and fishes that could indicate a higher contribution of methanotrophic bacteria. These two factors may enhance methylation and methyl mercury transfer in the food web and thus, alternatively or complementarily to the impact of the anthropogenic activities, may explain mercury differences observed in fishes from the Iténez River in comparison to the two other rivers. Public Library of Science 2013-05-31 /pmc/articles/PMC3669100/ /pubmed/23741452 http://dx.doi.org/10.1371/journal.pone.0065054 Text en © 2013 Pouilly et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Pouilly, Marc
Rejas, Danny
Pérez, Tamara
Duprey, Jean-Louis
Molina, Carlos I.
Hubas, Cédric
Guimarães, Jean-Remy D.
Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title_full Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title_fullStr Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title_full_unstemmed Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title_short Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Iténez River, Bolivia
title_sort trophic structure and mercury biomagnification in tropical fish assemblages, iténez river, bolivia
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669100/
https://www.ncbi.nlm.nih.gov/pubmed/23741452
http://dx.doi.org/10.1371/journal.pone.0065054
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