We describe spatio-temporal variability of primary production (PP) and chlorophyll-a (Chl-a) concentration with environmental parameters during March-December 2010 period in the south-eastern coast of the Black Sea. PP was measured by a combination of 14C in-situ incubation experiments on natural phytoplankton assemblages. Primary production rates, varied notably within water column with 0.1-40 mg cm(-3) d(-1), were always determined in the upper part of the euphotic zone down to the 10% of light intensity depth. The depth-integrated production rates ranged from 285 to 565 mg cm(-2) d(-1) for the coastal station and from 126 to 530 mg cm(-2) d(-1) for the offshore station (ANOVA, P>0.05). The average Chl-a concentrations within the euphotic zone ranged from 0.30 to 3.57 mu g L-1 for the coastal station and from 0.25 to 3.45 mu g L-1 for the offshore station (ANOVA, P<0.01), whereas the levels of depth-integrated Chl-a concentrations in the offshore station (9-80 mg m(-2)) were greater than in the coastal station (10 to 68 mg m(-2)) (ANOVA, P>0.05). The correlation between integrated PP and Chl-a values for the coastal station (r(2)= 0.98; P<0.01) was better than for the offshore station (r(2)= 0.12; P>0.05).