J. Phys. IV France 107 (2003) 839
Ventilation, a recently described step limiting heavy metal contamination in aquatic animalsJ.-C. Massabuau1 and D. Tram2
1 Laboratoire d'Écophysiologie et Écotoxicologie des Systèmes Aquatiques, UMR 5805-OASU, Université de Bordeaux 1, CNRS, place du Dr. Peyneau, 33120 Arcachon, France
2 IRSN-DPRE-SERLAB, Laboratoire de Radioécologie Expérimentale, Centre de Cadarache, bâtiment 186, BP. 1, 13108 Saint-Paul-lez-Durance cedex, France
Contamination of surface waters by metals, either in the marine or freshwater environment, is a fundamental question around the world. Bivalves are today largely used as biological monitors to evaluate the extent of metal contamination and to determine impacts on the food web in biogeochemical cycling. A fundamental question is thus the nature of the relationship between water contamination and metal concentration in the bivalve tissues. Indeed, the idea behind most studies is based on tissue accumulation data that is used to estimate the importance of the field contamination either measured by the dissolved, total and/or bound fractions. Until recently, chemical speciation was considered as a major factor controlling bioavailability of metals to organisms in the aquatic environment. However numerous examples show that it canot plain by it self all changes of metal accumulation process and that biological factors must be included. Up to now salinity, season, temperature, weight, growth rate and diet were reported to belong to these factors. We review recent work from our own laboratory demonstrating that ventilatory activity, i.e. the rate of water flowing over the gills, which is highly variable in water breathers according to the water physico-chemistry and animal metabolic requirement, is also of primary importance.
© EDP Sciences 2003