TrOphic transfer of major chemical pollUtants in arCAchoN bay: which impact on the Pacific oyster Crassostrea gigas ? (Ifremer / UMR EPOC in partnership with LSPC Ifremer and SIBA)
The TOUCAN project aims to propose first a multidisciplinary approach for a better knowledge on the occurrence, distribution and fate of major chemical pollutants in Arcachon Basin and their trophic transfer and toxic effects, considering both historic (PAHs, copper) and emerging pollutants (pesticides, UV-filters). For each type of pollutants, the latest analytical chemistry methods will be used to complete existing data for sediment, water column (dissolved phase and particulate organic matter (POM)) and transplanted oyster and acquire new and original data concerning the contamination level of marine phytoplankton, potential vector of trophic contamination. Seawater and oyster tissue will also be characterized by the determination of C and N elemental and isotopic ratios, such as C-to-chlorophyll a ratio in water. These analyses will qualify and quantify the contribution of the different sources of organic matter to the pool of POM constituting oyster diet.
Secondly, to better assess the mechanisms involved in the trophic transfer of pollutants and their toxicity, an experimental approach will be also developed during the project at the regional innovation platform of Bouin. Considering phytoplankton and oyster as primary producer and consumer respectively, the trophic transfer will be studied for copper and one of the organic pollutants selected for the field study. Depending on the concentrations measured in the field during the project, it could be metolachlore ESA, the main metabolite of the herbicide S-metolachlore that is one of the most frequently detected herbicide by-products in Arcachon Basin or one UV-filter.
The data collected during the TOUCAN project are expected to contribute to a better knowledge of the chemical anthropogenic pressure on Arcachon Basin and on the transfer and toxicity of both historic and emerging substances threatening both environmental and human health.