TP17 Biomarkers
Tuesday, 15 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(BIA-1117-834587) Biomarkers in barnacle Balanus improvisus from the Patos Lagoon estuary (Southern Brazil): pollution and seasonal effects.

Zanette, Juliano¹, Monserrat, José¹, Bianchini, Adalto¹, ¹ Fundação Universidade Federal do Rio Grande, Rio Grande, RS, Brazil

ABSTRACT- Biochemical biomarkers in aquatic organisms have been employed in monitoring programs to denote pollution in aquatic ecosystems. Nevertheless, in some cases biomarkers can be influenced by seasonality. In the present study, barnacles Balanus improvisus were collected in one site a priori without sources of pollution (reference site) and in two polluted sites at Patos Lagoon Estuary (Southern Brazil). Barnacles were collected in summer and winter and whole-body tissues were employed for biochemical analyses. Barnacles from the polluted sites showed a higher glutathione S-transferase (GST) activity than those from the reference site in winter, suggesting major activation of phase-II biotransformation system by xenobiotics. Lower LPO levels were observed in barnacles from the polluted sites, which could be related to differences in unsaturated fatty-acid composition of membranes. A higher GST activity was observed for barnacles from the three sites in summer, suggesting seasonal changes in the endogenous cycles of these organisms. LPO levels were higher in winter barnacles than in summer ones, indicating that changes in environmental temperature would led to alterations in unsaturated fatty-acid composition of membranes. Antioxidant capacity (TOSC) values was lower in winter oysters than in summer ones, suggesting lower levels of antioxidants in that season. Absence of pollution effects on total metallothioneins-like proteins (MTs) levels suggest the need for further investigations considering different MTs isoforms. (Supported by RECOS project - Institutos do Milênio - Brazilian Ministry of Science and Tecnology.

Key words: biomarkers, barnacle, aquatic pollution, Balanus improvisus/i>