The conservation status of Sabellaria alveolata (L.) (Polychaeta: Sabellariidae) reefs in the Bay of Mont-Saint-Michel

Sabellaria alveolata reefs in the Bay of Mont-Saint-Michel, the most extensive intertidal biogenic structures in Europe, have shown a continuous deterioration in health status, particularly in their central regions. This decline correlates with the colonization of Pacific oysters (Crassostrea gigas) and increased silt deposition on the reef. The study, conducted before and after mussel farming expansions in 2001 and 2007, employed a spatial Health Status Index (HI) that integrated physical and biological parameters to assess the reef's condition. Findings indicate that trophic competition between cultivated and wild suspension-feeders, altered hydrodynamics leading to increased silt deposition, and recreational oyster harvesting with associated reef trampling are key factors contributing to reef fragmentation and degradation. This study underscores the need for targeted management strategies to conserve these vital biogenic structures.

Desroy, N., Dubois, S. F., Fournier, J., Ricquiers, L., Mao, P. L., Guerin, L., Gerla, D., Rougerie, M., & Legendre, A. (2011). The conservation status of Sabellaria alveolata (L.) (Polychaeta: Sabellariidae) reefs in the Bay of Mont-Saint-Michel. Zenodo. https://doi.org/10.5281/ZENODO.18192606