Interaction of pigment concentration and primary production with environmental condition in the Southeastern Black Sea

In the present study, qualitative and quantitative changing of phytoplankton, photosynthetic pigment ratios, primary production and related to environmental conditions were evaluated from February 2009 to December 2009 in the South Eastern Black Sea.In the CTD profiles, temperature and salinity values showed similar pattern of Black Sea characteristics. When the oxygenated layer was observed at depths of 40-60 meters during warm season, it was extent to 60-80 meters depths. The anoxic zone was determined at depth of 140 m. PAR was measured at depths of 27-30 meters. Light attenuation coefficient was calculated as 0.18±0.07 m-1 and 0.18±0.06 m-1 in the coastal and offshore waters, respectively.According to nutrients results, nitrate concentrations were higher than upper limit of the Black Sea (2,3 µg-at/L). Mean nitrate values ranged from 2.18-2.21 ?g?at/L in coastal and offshore waters, respectively. Mean nitrite values ranged from 0.07?0.09 ?g?at/L in coastal and offshore waters, respectively. Mean phosphate values ranged from 0.018-0.023 ?g?at/L and ?g?at/L in coastal and offshore waters, respectively. Silicate values determined at area did not higher than western part of the Black Sea (0.8-1.5 µg-at/L). Silicate concentrations ranged from 0.13 ?g?at/L in coastal and offshore waters, respectively.At the study area, the phytoplankton blooms were observed in May and September. In addition to these blooms, a third bloom that caused by coccolithophore was also detected on November. The relationship between cell number and pigment concentrations showed that fucoxanthin, peridinin and 19?-hexanoyloxifucoxanthin ratios can be used as a marker for diatom, dinoflagellates and coccolithophore groups, respectively.In the C-14 experiment, production rate varied between 431 and 1392 mgCm-2day-1 in the coastal waters, and between 126 and 1332 mgCm-2day-1 in the offshore waters.