Serpulid abundances in Phyllophora crispa (Rhodophyta) mats and Posidonia oceanica meadows near Giglio Island (Tyrrhenian Sea, Italy)

This dataset contains abundance data of Serpulid Polychaetes on four stations around Giglio Island (Tyrrhenian Sea, Italy). All data was generated between May and July 2019 by SCUBA diving. We aimed to assess the diversity and abundance of sessile organisms within the P. crispa mats in comparison to well-investigated P. oceanica meadows.