Document Detail

Potential risks of natural mercury levels to wild predator fish in an Amazon reservoir.
MedLine Citation:
PMID:  21927790     Owner:  NLM     Status:  Publisher    
Mercury (Hg) is a toxic metal that bioaccumulates in aquatic organisms and along food chain. Many studies have reported the problem of mercury exposure in aquatic systems from Amazon basin, but very few have focused on the potential risks to wild fish. The present study reports the bioaccumulation of mercury and alterations in target organs of the predator fish Hoplias malabaricus (traíra) from Samuel reservoir, Amazon basin, Northern Brazil. About 18% of fish had mercury levels in muscle exceeding the safe limit for ingestion through food, established by WHO (0.5 μg Hg g(-1)). Fish were separated in two groups according to mercury bioaccumulation in liver (<0.2 μg Hg g(-1)-group I and >0.2 μg Hg g(-1)-group II) for biomarker comparisons. Catalase activity and number of macrophage centers were statistically higher in group II, confirming the potential of Hg to interfere with redox balance and to recruit defense cells to the liver. Conversely, erythrocyte nuclear alterations were less frequent in group II, indicating a more rigorous selection of erythrocytes or hormesis pattern of response. Glutathione S-transferase activity, lipid peroxidation, and histopathological analyses were not statistically different in the liver and gills of both groups. Comparison of lipid peroxidation levels of these fish with others captured in Southern Brazil during another study and the high incidence of morphological alterations in the liver and gills suggest that the bioaccumulation of mercury during continuous exposure is posing potential risks to the species.
Grazyelle Sebrenski da Silva; Francisco Filipak Neto; Helena Cristina Silva de Assis; Wanderley Rodrigues Bastos; Ciro Alberto de Oliveira Ribeiro
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-9-17
Journal Detail:
Title:  Environmental monitoring and assessment     Volume:  -     ISSN:  1573-2959     ISO Abbreviation:  -     Publication Date:  2011 Sep 
Date Detail:
Created Date:  2011-9-19     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8508350     Medline TA:  Environ Monit Assess     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Departamento de Biologia Celular, Universidade Federal do Paraná, Cx. Postal 19031, CEP: 81.531-990, Curitiba, Paraná, Brazil.
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