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Flood-pulse and trophic position modulate mercury concentrations in fishes from an Amazon floodplain lake.
de Castro Paiva, Thais; Dary, Eurizângela Pereira; Pestana, Inácio Abreu; Amadio, Sidineia Aparecida; Malm, Olaf; Kasper, Daniele.
Afiliação
  • de Castro Paiva T; Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brazil. Electronic address: thaispaiva@biof.ufrj.br.
  • Dary EP; Instituto Nacional de Pesquisas da Amazônia, 69060-020, Manaus, AM, Brazil.
  • Pestana IA; Universidade Estadual do Norte Fluminense Darcy Ribeiro, 28013-602, Campos dos Goytacazes, RJ, Brazil.
  • Amadio SA; Instituto Nacional de Pesquisas da Amazônia, 69060-020, Manaus, AM, Brazil.
  • Malm O; Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brazil.
  • Kasper D; Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brazil.
Environ Res ; 215(Pt 2): 114307, 2022 12.
Article em En | MEDLINE | ID: mdl-36115421
ABSTRACT
Mercury (Hg) bioaccumulation can be influenced by biological characteristics (e.g., trophic position) and environmental changes (e.g., seasonal flood-pulse), as it can create site conditions conducive to methylation and alter the availability of food to biota. This study aimed to relate total mercury (THg) and methylmercury (MeHg) concentrations in fishes of an Amazonian lake (Catalão Lake) to their dietary changes during different hydrological seasons (rising-, high-, falling-, and low-water). Levels of THg, MeHg, and stable isotopes of nitrogen and carbon (δ15N and δ13C) were determined in the muscles of six fish species Rhytiodus microlepis, Hemiodus sp., Triportheus albus, Anodus elongatus, Pellona flavipinnis and Acestrorhynchus falcirostris. Triportheusalbus, an omnivorous fish, showed a significant relationship between Hg concentrations and δ13C signatures (negative regression; THg p = 0.0001 and MeHg p = 0.0002), as well as between Hg and δ15N signatures (positive regression; THg p = 0.003 and MeHg p = 0.021), indicating that changes in feeding habits influenced the Hg concentrations in this species. The herbivorous R. microlepis presented the highest MeHg concentrations during the high-water season, reflecting Hg methylation in its diet (macrophyte roots) during flooded season. The piscivorous A. falcirostris had the lowest THg concentrations during this season because of lower prey availability. Slopes of the regressions between the Hg concentrations and δ15N values followed the sequence of rising- < high- < falling-water seasons (THg 0.06 < 0.11< 0.15; MeHg 0.07 < 0.10 < 0.17), indicating that the difference between the THg and MeHg concentrations observed for lower- and higher-trophic-level fish increased during the falling-water season, resulting in trophic biomagnification. The present study shows that feeding habit and the flood-pulse influence mercury concentrations in the muscle of fishes from Catalão Lake.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Lagos / Peixes / Mercúrio Limite: Animals Idioma: En Revista: Environ Res Ano de publicação: 2022 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Lagos / Peixes / Mercúrio Limite: Animals Idioma: En Revista: Environ Res Ano de publicação: 2022 Tipo de documento: Article