How depth and substratum type affect diversity and distribution patterns of echinoderms on the continental shelf in the South-eastern Adriatic Sea?

Abstract

This study investigated how a combination of abiotic factors, and namely depth and substratum type, affected the spatial and temporal distribution of echinoderms on the continental shelf in the South-eastern Adriatic Sea. Samples were collected from 19 stations at depths from 0 to 120 m by scuba diving and bottom trawling. A total of 46 species belonging to the phylum Echinodermata were found. Substratum was the most important factor influencing the structure of echinoderm assemblages, while depth was not as important for the distribution pattern of echinoderms in the upper infralittoral zone of the Adriatic Sea. During the study period there were no seasonal differences among samples from the same sites. Species diversity of echinoderm assemblages was not significantly different between samples collected by scuba diving or bottom trawling, while species composition varied by sampling method.