EFFECTS OF NATURAL FACTORS (SALINITY AND BODY-WEIGHT) ON CADMIUM, COPPER, ZINC AND METALLOTHIONEIN-LIKE PROTEIN-LEVELS IN RESIDENT POPULATIONS OF OYSTERS CRASSOSTREA-GIGAS FROM A POLLUTED ESTUARY

Citation
C. Mouneyrac et al., EFFECTS OF NATURAL FACTORS (SALINITY AND BODY-WEIGHT) ON CADMIUM, COPPER, ZINC AND METALLOTHIONEIN-LIKE PROTEIN-LEVELS IN RESIDENT POPULATIONS OF OYSTERS CRASSOSTREA-GIGAS FROM A POLLUTED ESTUARY, Marine ecology. Progress series, 162, 1998, pp. 125-135
Citations number
57
Categorie Soggetti
Marine & Freshwater Biology",Ecology
ISSN journal
01718630
Volume
162
Year of publication
1998
Pages
125 - 135
Database
ISI
SICI code
0171-8630(1998)162:<125:EONF(A>2.0.ZU;2-#
Abstract
The Gironde estuary has been shown to be the most Cd-contaminated area in France. Oysters Crassostrea gigas of different size classes were s ampled from 3 sites between the mouth and 25 km upstream, to study the relative importance of natural and contamination factors on metal acc umulation and metallothionein-like protein (MTLP) induction. The highe st metal and MTLP concentrations were observed in the digestive gland. In all organs, the 3 metals were mainly cytosolic. An inverse relatio nship was generally observed between weight of soft tissues and metals or MTLP concentrations in the whole soft tissues, whereas the influen ce of weight on metal distribution among cytosolic and insoluble fract ions was small. When oysters with similar weight of soft tissues were considered, no influence of salinity at different sites was found for Cu and Zn whereas the lowest soluble and insoluble Cd concentrations w ere observed at the mouth of the river. Salinity did not influence Cu and Zn distribution among the cytosolic or insoluble fractions whereas cytosolic Cd in gills and digestive gland (%) was higher at the mouth of the estuary than upstream. MTLP and metal concentrations were gene rally positively correlated except at those sites where metal concentr ations were lowest. However when multiple regression analyses were per formed, weight appeared also as a major or an important factor to expl ain variations of MTLP levels, the prevalence of this natural factor v ersus contamination factors being different at different sites.