p. 97 - 115

DISTRIBUTION OF CHLOROPHYLL a PHAEOPHYTIN a AND
PRIMARY PRODUCTION IN THE WESTERN BLACK SEA
(May, 1982) 


A. S. Bologa 1), Zemfira P. Burlakova 2),
V. D . TCHMYR 2) AND V. I. KHOLODOV 2) 

1) Romanian Marine Research Institute Constanta
2) Institute of Biology of Southern Seas Sevastopol


Abstract
In the prebosphoric, Caliacra and predanubian sectors
of the Black Sea the chlorophill a concentrations
ranged between 0.30 to 0.55, 0.25 to 0.50 and 3 to
35 mg m-3 respectively; vertically, in the prebosphoric
and Caliacra sectors two maxima occurred, at the surface
and at the lower levels of the euphotic zone, while in
the predanubian sector only a surface maximum was evinced.
The phaeophytin a concentrations ranged between 0.02 to
0.66, 0.04 to 0.29 and 3 to 34 mg m-3 respectively;
vertically, its distribution, concerning the maximum
values, was similar to that of chlorophill a. The
surface primary production ranged between 10 to 39, 
17 to 25 and 140 to 1,530 mg C m-3 day-1 respectively;
vertically, the maxima occurred in all sectors at 0 m.
The following maximum assimilation numbers were calculated:
12.5, 7.0 and 5.3 mg chl a-1 hour-1 respectively. The very
high chlorophill a content and primary production in the
predanubian sector, unlike the other two sectors, are due
to the extreme eutrophication due to the extreme eutrophi-
cation due to the nutrient supply from the Danube and, 
implicity, to the frequent occurrence of intense phyto-
plankton blooms.