Seasonal occurrence and distribution of gelatinous macrozooplankton of the Sinop Peninsula in the Southern Black Sea

The aim of this study was to determine the occurrence and distribution of gelatinous macrozooplankton in the southern Black Sea. The abundance and biomass of gelatinous organisms and their relationship with physical parameters were determined between March 2015 and February 2016 in the Sinop Peninsula of the southern Black Sea. Monthly samplings were conducted at six stations located in both the coastal and open sea. Gelatinous macrozooplankton was collected using vertical hauls (plankton net mouth opening 50 cm, mesh size 210 mu m). The abundance and biomass of the gelatinous macrozooplankton increased in both summer and spring; the minimum values were recorded in winter. Maximum abundance was 43.33 m(-2) (August 2015) in the open sea and 39.17 m(-2) (July 2015) in the coastal areas. The highest biomass was 282.47 g.m(-2) in coastal areas (April 2015) and 205.68 g.m(-2) in the open sea (March 2015). We determined that the gelatinous macrozooplankton in the southern Black Sea decreased from 2002 to 2008. The distribution of species differed from the values observed in previous studies. No significant difference in abundance and biomass was observed between the open and coastal stations. Temperature was the main factor correlated with gelatinous macrozooplankton blooms.