Use of biomarkers in resident organisms as a tool for environmental monitoring in a cold coastal system, Tierra del Fuego Island.

Antioxidant status of Nacella (P) magellanica and Mytilus edulis related with heavy metal in sediment and tissues were analysed in five stations close to Ushuaia city in winter and spring. The principal component analysis produced a two-dimensional pattern of the degree of similarity between sites. The Industrial-Urban Contamination Index (IUCI) showed that the Industrial Zone (IZ) and Oil Marine Station (OMS) represent areas with anthropic inputs. Heavy metals have differential association with biomarkers depending on the species. In limpets, digestive gland presented major activities of enzyme defence in winter and gonads have shown higher values of Catalase (CAT) during spring while lipid peroxidation (LPO) presented higher values in IZ. For mussels CAT and LPO increased in spring time. For superoxide dismutase (SOD) peaks have been detected in IZ and NW stations for winter. Differences in biomarker responses due to seasons did not influence the grouping of the sites into references and contaminated groups.

Evaluation of sublethal biomarkers in Litopenaeus vannamei on foodborne exposure to methyl parathion.

Sublethal effects of foodborne exposure to methyl parathion (0.62 and 1.31 microg methyl parathion*g(-1) dry weight of food) on juveniles of Litopenaeus vannamei using integrated biochemical (acetylcholinesterase (AChE) and ATPases) and physiological (feeding rate (FR), egestion rate (ER), and hepatosomatic index (HI)) biomarkers were evaluated. The HI was significantly higher in controls than in pesticide treatments. The FR was significantly lower in controls than in pesticide treatments while no significant differences were detected in the ER. AChE activity was significantly higher in controls than in pesticide treatments (control = 0.11 +/- 0.02; solvent control = 0.11 +/- 0.03; 0.62 = 0.07 +/- 0.01; 1.31 = 0.08 +/- 0.02 microM*min(-1)*mgprotein(-1)). The total-ATPase activity was significantly lower in controls than in pesticide treatments (control=77.90+/-12.41; solvent control = 83.69 +/- 22.05; 0.62 = 110.03 +/- 22.17; 1.31 = 121.54 +/- 19.84 microM P(i)*h(-1)*mgprotein(-1)). The Mg(2+)-ATPase activity was significantly higher in treatments than in controls (control = 65.14+/-10.76; solvent control = 75.12 +/- 21.10; 0.62 = 100.53 +/- 20.97; 1.31 = 108.94 +/- 17.26 microM P(i)*h(-1)*mgprotein(-1)). Finally, the results obtained for the Na(+)/K(+)-ATPase activity were significantly higher in control and in 1.31 than in solvent control and in 0.62 (control = 14.06+/-2.63; solvent control=7.30 +/- 4.13; 0.62 = 7.60 +/- 3.81; 1.31 = 13.42 +/- 2.88 microM P(i)*h(-1)*mgprotein(-1)). The results in this study showed that pulse exposures to methyl parathion via food could elicit measurable effects on the marine shrimp L. vannamei, indicating that foodborne exposure can be a reliable toxicological procedure and, if combined with pulse exposures, could also simulate more realistic exposure scenarios.