20/12/2023

Frongia C., Pagani S., Chindris A., Graham P., Carboni S., Brundu G.

Abstract

Oyster farming is considered a sustainable seafood production with environmental benefits related to water purification, but negative effects on the benthic ecosystem functioning could be caused by the release of feaces and pseudofeaces, collectively called bio-deposits. In this study, we compared the first time the daily bio-deposit production of Crassostrea gigas and Ostrea edulis in two Mediterranean coastal lagoons and in laboratory-controlled conditions. C. gigas resulted in a higher bio-deposit production than O. edulis in all the treatments, due to a higher ingestion rate of the former. Regardless to the species, differences were also recorded between lagoons, resulting S’Ena Arrubia in a higher bio-deposit production, consistent with a higher quality (i.e. POM/TPM ratio) and sedimentation rate of seston, than Corru S’Ittiri, indicating that the bio-deposition is strongly related to the environmental and trophic conditions of the farming site. Our results suggest that the bio-deposit production is site-specific, and it must be evaluated specifically in each farming site and for each oyster species. This study presents new data on the bio-deposition of C. gigas and O. edulis and contributes to our understanding of the potential impact of oyster farming.

Regional Studies in Marine Science 67