Fate of copper in intensive shrimp farms: bioaccumulation and deposition in pond sediments

Abstract

We present the distribution of Cu in water, sediments and biomass from intensive shrimp (Litopenaeus vannamei Boone, 1931)) farming in northeastern Brazil. The results show no difference in dissolved Cu concentrations between waters entering and leaving the ponds. However, there was a large export of particulate Cu to adjacent environments, showed by extremely high particulate (112 µg.L , being 5 to 7 times higher than the local background. Pond management procedures result in a peculiar vertical distribution of Cu with peak values occurring at sub-surface depths in pond bottom sediments. Bioavailable Cu reaches about 20% of the total Cu content in sediments. Notwithstanding the relatively high Cu bioavailability, concentrations in shrimp muscle (23.2 to 63.4 µg.g -1 d.w.) were similar to reported values for reared and natural L. vannamei populations, and much lower than acceptable maximum limits for human consumption. Concentrations in the exoskeleton were always higher than in muscle. Increasing Cu mass, and to a lesser extent Cu concentrations in muscle tissues, occurred simultaneously to a decrease in Cu mass and concentrations in the exoskeleton and vice versa, suggesting a dynamical exchange of Cu between the two compartments. Although Cu fate in intensive shrimp culture does not result in increasing Cu exposure to consumers, the activity is an important source of this metal to adjacent ecosystems, in particular in the pristine environments where most aquaculture activities in NE Brazil takes place. , sendo estes valores de 5 a 7 vezes mais altos que as concentrações naturais dos solos e sedimentos locais. O manejo dos tanques de criação resulta em perfis de distribuição de Cu em sedimentos com maiores concentrações em subsuperfície. A biodisponibilidade do Cu nestes sedimentos é elevada e atinge cerca de 20% da concentração total. Apesar da biodisponibilidade elevada, as concentrações de Cu em músculo do L. vannamei (23.2 a 63.4 µg.g -1 peso seco) são similares aos valores reportados para populações naturais da espécie e em diversos de cultivo em outros países, e estão bem abaixo dos limites máximos permitidos para consumo humano. As concentrações de Cu no exoesqueleto foram maiores que no músculo. Um aumento da massa de Cu em músculo ocorreu simultaneamente à diminuição do Cu no exoesqueleto e vice-versa sugerindo uma troca dinâmica do Cu entre os dois compartimentos. Embora a presença do Cu no cultivo intensivo do L. vannamei não represente exposição significativa para os consumidores, a atividade é fonte importante de Cu para os sistemas aquáticos adjacentes. KeywordsPalavras-chave: carcinicultura intensiva, cobre, exportação e acumulação de Cu, Nordeste do Brasil. , 2002). Therefore, dilution capacity of the estuary has been decreasing over the past decades, maximizing the potential effect of pollutant emissions from anthropogenic sources.

Tissue Distribution and Correlation Profiles of Heavy-Metal Accumulation in the Freshwater Crayfish Astacus leptodactylus

“…Despite the necessity of this element in tissues, its concentrations were lower than detection limits in gill and abdominal muscle samples and therefore were not considered for correlation analysis. This element was present in exoskeleton and hepatopancreas despite the its absence in gill and abdominal sample, possibly because the former two tissue types are known sites of bioaccumulation and therefore more likely to display greater concentrations of Co (Ahearn et al 2004;Lacerda et al 2009). In addition, low overall tissue levels of Co can be explained by the fact that Co bioaccumulation is inhibited in the presence of other heavy metals-especially Ni, Cu, Zn, and Mn-possibly due to competitive interactions between those cations (Norwood et al 2007).…”

Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

“…These results suggest that all Hg that enters the farm area via fish farming practices may accumulate in the farm's sediments. Lacerda et al (2009) and Costa et al (2013) also reported that the majority of Cu emitted in the lower Jaguaribe River as a result of aquafeed used in shrimp farming does so in the bottom sediments.…”

Desafios da carcinicultura: aspectos legais, impactos ambientais e alternativas mitigadoras

“…De uma maneira geral, os potenciais contaminantes introduzidos nos corpos receptores junto com os efluentes são: i) antibióticos e agentes antimicrobianos (Gräslund & Bengtsson, 2001;Anh et al, 2010); ii) nutrientes (e.g. amônia, nitrato, fosfato) que podem gerar eutrofização de corpos d'água (Jones et al, 2001;Gál et al, 2003;Figueirêdo et al, 2006;Anh et al, 2010;Souza, 2013) e/ou proliferação de algas produtoras de toxinas; iii) e metais traços e maiores, incluindo Hg (Lacerda et al, 2006(Lacerda et al, e 2009Lacerda et al, 2011;Costa et al, 2013). Antibióticos e antimicrobianos são utilizados com fins terapêuticos, profiláticos e como promotores de crescimento, para melhorar aassimilação de alimentos e, consequentemente, aumentar a produção (Barton, 2000).…”