Bioaccumulation of mercury and selenium in Trichiurus lepturus

Abstract

Mercúrio e selênio foram determinados no tecido muscular do peixe espada (Trichiurus lepturus) de três áreas costeiras (Baía da Ilha Grande, Baía de Guanabara and Búzios, Estado do Rio de Janeiro) que apresentam diferentes condições ambientais, localizadas no sudeste brasileiro. Hg foi determinado por espectrometria de absorção atômica em vapor frio (CV-AAS) e Se por espectrometria de absorção atômica com forno de grafite (GF-AAS). As concentrações variaram de 0,44 a 0,87 µg Hg g -1 e de 0,0050 a 3,12 µg Se g -1 , em peso seco. Foram observadas diferenças significativas na concentração de mercúrio e na razão molar selênio:mercúrio entre as áreas. O comprimento total e os intervalos de tamanho influenciaram na acumulação de mercúrio, entretanto estes parâmetros biológicos não influenciaram na acumulação de selênio. Foi observado um excesso de selênio em relação ao mercúrio. Provavelmente, as diferenças regionais podem ser em parte atribuídas às diferenças nas condições ambientais (temperatura da água e produção primária), e também a outros fatores, tais como a escolha das presas e a disponibilidade destes elementos nos ambientes.Mercury and selenium were assessed in the muscle tissue of cutlassfish (Trichiurus lepturus) from three coastal areas (Ilha Grande Bay, Guanabara Bay and Búzios coast, Rio de Janeiro State, Brazil) that present different environmental conditions, localized in Southeastern Brazil. Hg was determined by cold vapor atomic absorption spectrometry (CV-AAS) and Se was determined by graphite furnace atomic absorption spectrometry (GF-AAS). Across sites, mercury and selenium in this fish ranged from 0.44 to 0.87 µg Hg g -1 and 0.0050 to 3.12 µg Se g -1 dry wt. Significant differences were observed in mercury concentrations and Se:Hg molar ratios among the areas. The total length and size intervals presented a significant influence on the accumulation of mercury, whereas this pattern was not observed for selenium. A large excess of selenium in relation to mercury was observed. Probably, the regional differences can be partly attributed to differences in the prevalent environmental conditions (water temperature and primary production), and also to other factors, such as prey choices and availability across locations.

A review of estuarine fish research in South America: what has been achieved and what is the future for sustainability and conservation?

“…In a series of studies in estuaries of Rio de Janeiro (mainly Ilha Grande, and also including Guanabara Bay and the Búzios coast), Seixas et al . () have investigated both selenium and organic methyl mercury accumulation in fishes. They found considerable natural variation ascribed to prevailing environmental conditions.…”

Mercury: Biogeochemical and Toxicological Aspects and Levels Found in Marine Fish Along the Southern and Southeastern Coasts of Brazil

“…That same year, Seixas et al, (2012) conducted a study which analyzed the concentrations of Hg and Se (selenium) in muscle tissue of Trichiurus lepturus (largehead hairtail) caught in three different areas of Brazil: Guanabara Bay, Ilha Grande Bay, and on the coast of Buzios, all in the state of Rio de Janeiro. Significant differences were observed in the concentration of Hg between the areas.…”

Mercury in tropical and subtropical coastal environments

“…Coastal pollution by mercury and other pollutants might have a role to play in this scenario at the local scale. Studies with Trichiurus lepturus (1) Shrestha et al, 1988 – Venezuela; (2) Mol et al, 2000 - Suriname; (3) Costa et al, 2009; Barbosa-Cintra et al, 2011 - NE Brazil; (4) Kehrig et al, 2004; Cardoso et al, 2009; Kehrig et al 2009c; Kehrig et al, 2010; Kehrig et al, 2011; Carvalho et al, 2008; Di Beneditto et al 2012; Muto et al, 2011; Bisi et al, 2012; Seixas et al, 2012a, b; Seixas et al, in press - SE Brazil; (5) Saei-Dehkordi et al, 2010 - Persian Gulf; (6) Prudente et al, 1997 - Philippines.…”