Demersal trawl discards with spatial and bathymetric emphasis in the Turkish coast of the Aegean Sea

The aim of the present study is to investigate the spatial and bathymetric distribution of demersal trawl discards in the Turkish coast of the Aegean Sea. Trawl hauls were performed in the legal trawling areas of the Turkish coast of the Aegean Sea (Canakkale, Foca, Karaburun, Sack, Gulluk) between 2010 and 2012 by commercial trawlers. Depth of the trawl hauls ranged from 30m in the south to 450m in the north. As a result of 311 trawl samples, 200 species belonging to eight taxonomic groups (Porifera, Cnidaria, Annelida, Arthropoda, Mollusca, Echinodermata, Tunicata, Chordata) were identified. The changes in species composition based on depth and region were determined to be statistically significant. It was found that species composition distinctly changed around 200m. In a regional assessment it was determined that the Turkish coast of the Aegean Sea is divided into three sub-regions, i.e. Canakkale, Foca-Karaburun-Sack and Gulluk. The results of similar studies conducted in the Mediterranean were investigated and compared with the findings of this study.