Determination of polychaeta (Annelida) fauna and some environmental factors affecti̇ng their distribution in Büyükçekmece bay (Marmara sea)

This study is conducted with the aim of exhibiting polychaeta species that live in Büyükçekmece Bay, which is located northeast of Marmara Sea, and the environmental factors that effect their distribution. The study is conducted on 9th-10th-11th May 2016. The results exhibit 68 polychaeta species and 8340 individuals. The ecological properties of Büyükçekmece Bay are examined and results Show varying degrees of temperature between 14,5- 17,8 (ºC), of salinity between 21,3-34 (‰), of dissolved oxygen between 2,7-12,1 mg/L. Varying degrees of mud percentage between %1,46-97,58, of total organic carbon between %9,11-80,16, of total calcium carbonate between %0,17-7,26, As3+ <0,01-16,65 µg/g, As5+ 1,8-38,8 µg/g, of organic arsenic between 6,6-37,7 µg/g, of total arsenic between 13,6-73,9 µg/g and domoic acid between <0,02-1,82 ppm are found on the examined stations. The study exhibits increasing salinity, mud percentage, total organic carbon, arsenic and domoic acid rates and decreasing temperature, dissolved oxygen and total calcium carbonate rates as moving from coast to high-sea. Study shows that variety index values change between H' 0-3,33 on the examined stations and high H' values are seen in the sites with high mud percentage and dissolved oxygen values. Sperman correlation results Show strong positive relationships between species-individual numbers and temperature, dissolved oxygen and total calcium carbonate. The correlation result also indicate strong negative relationships between total organic carbon and mud percentage, As5+ and total arsenic. Bray- Curtis similarity index result exhibit 4 stations with 20% rates and 3 groups.