Demersal fish and megafaunal assemblages on the Cretan continental shelf and slope (NE Mediterranean): seasonal variation in species density, biomass and diversity

The demersal fish and megafaunal assemblages in the area of Heraklion Bay, Crete, were sampled during four research cruises from September 1994 to September 1995 within the framework of the CINCS project, using a stratified trawl survey at depths ranging from 50 to 1000 m. The sampling at 1000 m depth was the deepest ever made in Greek waters, using a bottom otter trawl. Species density and biomass were found to vary between depths and seasons, with higher values occurring at the shallow stations. Species distribution and communities are also reported. A total of 127 species of osteichthyes, chondrichthyes, crustaceans, and cephalopods were recorded, four of which were found for the first time in Greek waters. Percent similarity index (PSI) was used to assess the differences in the relative abundance of species pairs between depth zones and seasons. Principal component analysis (PCA) was applied to examine station variability statistically.