Sediment toxicity of the Monjolinho river basins (São Carlos - SP): emphasis in the substances copper, aldrin and heptachlor / Toxicidade dos sedimentos da Bacia Hidrográfica do Rio Monjolinho ( São Carlos - SP): ênfase nas substâncias cobre, aldrin e heptacloro

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

This work aimed evaluates the Monjolinho river quality through physical, chemical, biological and ecotoxicological analysis. Samples of water and sediment were collected in July/03; October/03; January/04 and April/04 in fourteen locations. Moreover studies about survival, growth and gills morphology were performed in organisms exposed to copper, aldrin and heptachlor in chronic concentrations (some pollutants detected in this system). The overall results showed that system is all degraded. The sediment toxicity presented seasonal variation, in the manner that the highest mortality percentage occurred in January/04. Besides, the specie P. reticulata was further sensitive than D. rerio in both seasons (july/03 and January/04). Histological analysis of test organisms exposed in sediment samples showed gills alterations after seven days. The reference substances: copper, aldrin and heptachlor presents negative effects on survival, growth and gills morphology en tests organisms exposed in sub-lethal concentrations after seven days. These results suggesting that these substances can represents risks for the maintenance of the fish species, as well as, for the aquatic community’s balance.

ASSUNTO(S)

rio monjolinho toxicity copper toxicidade sediment monjolinho river cobre sedimento aldrin heptacloro aldrin heptachlor

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