Southern Baltic, including the Bornholm and Gdansk Basins. Since 1983 the southern part of the Gotland Basin was also included.

Primary production in the water column

The main goal of these investigations was the determination of phytoplankton productivity and its temporal and spatial variability. The measurements were conducted at 3 stations located in the following areas: station P1 (Gdansk Deep; 54° 50'N, 19° 20'E), station P140 (Gotland Deep; 55° 36'N, 18° 26'E) and station P5 (Bornholm Deep; 55° 14'N, 15° 59'E). Up to 10 experiments were performed per year. Primary productivity was measured by an in situ C14 isotopic method at six depth levels of the euphotic layer (0, 2.5, 5, 10, 15, 20m). Simultaneously, the chlorophyll-a concentrations were determined spectrophotometrically in 90% acetone extracts of GF/F Whatman filters onto which the sea water had been filtered. No data are available for 1975. In the period 1976-1982, data were collected mainly in the Gdansk Deep. There are 261, 81 and 112 series for stations P1, P140 and P5, respectively.

National Marine Fisheries Research Institute
Kollataja 1
Gdynia

81-332
Poland