Dataset on the epibenthic abundance of Foraminifera on P. crispa and P. oceanica habitats in the NW Mediterranean Sea (Giglio Island, Italy). Samples were obtained via SCUBA diving in summer 2019 and analyzed by microscopic determination and counting of specimens. Sampling was part of a larger project on the diversity of the epiphytic invertebrate community on P. crispa mats in the area. The dataset includes details on the sampling efforts, diversity indices (Shannon, Pilou), and density of colonies m-² substrate (Indcount per sqm sub).The dataset includes information about the ecotype as defined by Mateu-Vicens et al., 2014, the test type (column "Test"), bearing of symbionts (yes (Y), no (N), chloroplast husbandry (CH)), and categorization as Large Benthic Foramineran (LBF; yes (Y) or no (N)), which can be found under "further details".