MA8 Ecotoxicology of Tropical Aquatic Environments
A105 & A106
8:00 AM - 12:00 PM, Monday
(78A) Effect and exposure biomarkers in mangrove oysters (Crassostrea rhizophorae) from Brazilian coast.
Zanette, J1, Monserrat, J1, Bianchini, A1, 1 Fundação Universidade Federal do Rio Grande, Rio Grande, RS, Brazil
ABSTRACT- Estuaries are generally impacted by anthropogenic pollution. Thus, biochemical responses in estuarine organisms have been used to infer pollution effects in the biota inhabiting these ecossystems. Nevertheless, these responses could change according with seasonality, since animal physiological cycles also could be altered along the year. Furthermore, contaminants bioavailability in water is also influenced by seasonality. In the present study, estuaries located in three Brazilian states (Paraná = PR, South coast; Espírito Santo = ES, Southeast coast; and Pernambuco = PE, Northeast coast) were monitored in two seasons (winter/summer for PR and ES, and rainy/dry season for PE). One control site and two sites with different pollution levels were choosen for each estuary. Gluthatione S-transferase (GST) enzime activity and lipid peroxidation level (LPO) was analyzed in gills of mangrove oysters (Crassostrea rhizophorae). The most polluted site in PR showed a dramatic increase in LPO levels when compared to the control site (P<0.05) in winter. This effect could be associated to the high pollutant load in this site. The most polluted site in PE showed an increased GST activity when compared to the control site in both seasons (P<0.05). This effect could be associated with an increase in the activation of phase-II biotransformation system by xenobiotics present in this local. In control sites, GST activity decreased from PR to PE in winter/rainy season. This could indicate a latitudinal effect, since a water temperature gradient is observed from PR to PE during winter season. This increase in GST activity could be a compensatory response to protect against lipid peroxides produced in higher levels in low temperatures, since cell membranes generally have more PUFA in this season to maintain membrane viscosity. (This work is part of RECOS project - Institutos do Milênio - Brazilian Ministry of Science and Technology)
Key words: Crassostrea rhizophorae, biomarkers, seasonality, latitudinal gradient