Ultrafiltration for environment safety in shellfish production: removal of oyster gametes in hatchery effluents
Résumé
Triploid oysters are favoured by the aquaculture industry because of their sterility, which results in two advantages: a faster growth than natural oysters and a constant quality throughout all the year, which is attractive for consumers. In France, these oysters are mainly produced by mating natural and tetraploid oysters whose production poses a risk for marine environmental biodiversity if biological material is released into the environment. Therefore, effluents from farms which could produce those kinds of oysters must be treated. The objective of this work was to treat shellfish hatchery effluents by ultrafiltration. The retention of gametes by the membrane, was validated for different scenario, 5 log removals were obtained, and their viability was evaluated after treatment highlighting a destruction of these species after air-backwash. The sustainability of the process facing this organic pollution on the duration of each test but also on the period of the study was demonstrated. A protection of the marine environment biodiversity is obtained with ultrafiltration processes.