PRIMARY PRODUCTION, MICROPLANKTON AND PRO CESSES OF CARBON AND SULFURCYCLING IN THE MARMARA SEA

Corresponding research was accomplished in October 1992 during the pre datory ctenofore Mnemiopsis leydi invasion into the Marmara sea. Prima ry production of phytoplankton at the surface was greater than 50 mg C /m(3), while its value in the water column ranged from 0.3 to 0.7 g C/ m(2) per day. The phytoplankton biomass in upper layer was 150 to 300 mg/m(3) and its production 40 to 100 mg/m(3) per day. Average biomass of nanoheterothrophs was 22 mg/m(3) and that of ciliates 100 mg/m(3) w ith its range at some stations between 200 to 1200 mg/m(3). The stock of labile organic matter in upper water layer was 2-4 mg C/m(3), decre asing with depth about 2 times. The stock of labile sulfides in bottom sediments was 20 to 100 mg S/1 of wet silt and the rate of their form ation 2-3 mg S/1 per day. The data thus obtained were used for evaluat ion of modern ecological status of the Marmara sea during its massive invasion by the ctenophore Mnemiopsis.