Avaliação ecotoxicológica dos sedimentos das represas de Barra Bonita e Bariri (SP) e estudos sobre a adsorção e dessorção do Hg, através de ensaios realizados com peixes (Danio rerio e Oreochromis niloticus)

• Ano de defesa: 2005
• Autor(a) principal: Carvalho, Solange de [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Peixe; Toxicologia; Mercurio; Represas; Biodisponibilidade; Fishes
• Link de acesso: http://hdl.handle.net/11449/144110; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/13-09-2016/000330180.pdf

The objective of this paper was to study the Barras Bonita's and Bariri's reservoir sediment, throw toxicity tests carried out with fishes, and also to analyze the role of the sediment in the bioavailability of Hg. The experiment was set up according to seven treatments: C= Control (only water, without sediment); SC= control sediment; SBB= Barra Bonita's reservoir sediment; SBI= Bariri's reservoir sediment; SSHg= control sediment, experimentally cantaminated - spiking with 1.0 mg/L Hg; SHgCL50= control sediment, maintained in constant contact with contamined water (mercury), at the concentration of 0.2 mg/L Hg and, HgCL50 = dilution water, at the concentration of mercury 0.2 mg /L Hg. The results showed low mortality of the exposed fish to the Barra Bonita's and Bariri's reservoir sediment and low contamination with mercury on this compartment. At the end of this experiment, the exposed fishes showed lows levels of Hg bioaccumulation. The analysis of the treatment SHgCL50 showed that sediment adsorved part of mercury contained in the water column, wich could be noticed by the bioaccumulation results, as the fishes of this treatment showed low Hg levels when compared with the treatment of concentration 0.2 mg/L of Hg (absence of sediment). It seemed that sediment play a role of a Hg filter. Apparently, the sediment satured with Hg (treatment SSHg) did not contaminante the water colunm, as analysis in the sediment after and before the experiment showed no differences in the Hg concentration, and the fishes exposed to this treatment accumulated low levels of Hg