Toxicité d'un désherbant, l'atrazine-simazine, sur les jeunes stades larvaires de Crassostrea gigas et sur deux algues fourrages, Isochrysis aff-galbana et Chaestoceros calcitrans

Corn culture has strongly developed in Aquitaine (France) over the past years, and lead to an increased use of pesticides and herbicides. One of the most commonly used formulations around the coast of the Arcachon Bay, an historical oyster spat capture zone, is the Atrazine-Simazine mix. The action limits of this product are defined on Crassostrea gigas larvae and on two nanoplankton test strains used in a controlled environment for their food, Isochrysis aff-galbana and Chaetoceros calcitrans. Herbicides can indeed directly impact on oyster larvae, but they can also have a negative impact by interfering with the development of the algae used as aquaculture feed and feed for veligeres.