Chromium accumulation and biomarker responses in the Neotropical fish Prochilodus lineatus caged in a river under the influence of tannery activities.

In order to assess the effects of tannery effluents (TE) in organism health, juveniles of Prochilodus lineatus were submitted to in situ tests at four different river locations: site A - upstream of the tannery; site B - next to the tannery; and sites C and D - downstream of the tannery. After 96 h exposure in the river, samples of fish tissue, river water and sediment were collected in order to quantify chromium (Cr) concentrations. Tissue samples were used to assess the activity of ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST), the content of glutathione (GSH) and metallothionein (MT) and the occurrence of lipid peroxidation (LPO) and DNA damage. Higher Cr concentrations were detected in the water and sediments from site B and in the liver of fish confined at site B, compared to the other sites. Fish caged at site B demonstrated higher levels of liver MT and hepatic EROD activity in relation to fish caged at the other sites. Moreover, fish from site B presented increased liver and branchial GST activities, as well as more GSH in the liver, than fish from site A. There were no significant variations in the occurrence of LPO and DNA damage among fish caged at the different sites. Thus, TE increased Cr levels in the water, sediments, and fish livers and stimulated the synthesis of MT and GSH and the activities of EROD and GST. In conclusion, TE affect the quality of the river and promote changes in biochemical biomarkers and Cr accumulation in P. lineatus.

Multiple biomarker responses in Prochilodus lineatus subjected to short-term in situ exposure to streams from agricultural areas in Southern Brazil.

In order to assess the quality of streams susceptible to contamination by pesticides we apply biochemical and genotoxic biomarkers in the Neotropical fish Prochilodus lineatus submitted to in situ tests. Fish were caged, for 96 h, in two streams located in areas with intensive use of pesticides, the Apertados (AP) and the Jacutinga (JC), and in a small stream (Godoy stream ­ GD) found inside a forest fragment adjacent to a State Park. Biochemical parameters, such as biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST), non-protein thiols (NPSH), lipoperoxidation (LPO), protein carbonylation (PCO) and acetylcholinesterase (AChE) were evaluated in various fish organs, as well as genotoxic biomarkers (damage to DNA and occurrence of micronuclei and erythrocyte nuclear abnormalities). Samples of water and sediment were collected for analysis of metals (Cu, Cr, Pb, Ni, Mn, Cd and Zn), organochloride pesticides, and triazine and glyphosate herbicides. We observed an increase in liver GST activity in fish at AP and gill GST activity in fish at JC. An increase in liver LPO was also observed in fish exposed to AP and JC. The same animals also exhibited increased DNA damage and erythrocyte nuclear abnormalities (ENAs) compared to the fish kept in GD. A number of compounds showed concentrations higher than the permitted levels, in particular, dichlorodiphenyltrichloroethane (DDT), its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), hexachlorocyclohexanes (HCH), heptachloride, diclofluanid and aldrins. These pesticides were detected at higher concentrations in water and sediment samples from AP, followed by JC and GD. The Integrated Biomarker Response Index (IBR) indicated that AP and JC (AP: 21.7 > JC: 18.5 > GD: 12.6) have the worst environmental quality. Integrated biomarker analysis revealed that the alterations observed related well with the levels of environmental contaminants, demonstrating the effectiveness of this biomonitoring approach.