Molluscan assemblages associated with Halopteris scoparia of São Miguel Island (Azores, NE Atlantic)

A total of 40 macroalgal samples were collected by SCUBA diving across four coastal locations. Associated molluscan fauna were sorted, identified to species level, and quantified.

The dataset includes abundance records for 16 mollusc species (14 gastropods and 2 bivalves), together with measurements of algal dry biomass. The dataset supports analyses of species richness, abundance patterns, and community composition of macroalgal-associated mollusc assemblages in shallow coastal habitats. It provides a valuable ecological baseline for studies addressing biodiversity patterns, species responses to environmental change, and the structure of Atlantic island coastal ecosystems.