Baltic proper, Northern Baltic Sea, Gotland Basin, Bornholm Basin, Arkona Sea during the period 1983-1992 (data set limits: 54 39 - 56 02N; 14 05 - 21 05E)

Chlorophyll pigment concentrations in water bodies

Spectrophotometers

The amount of the chlorophyll a is an important characteristic of the phytoplankton photosynthesis activity which helps to determine the amounts of phytoplankton biomass and the trophic level of a water body. The aim of the research was to determine water trophic (biological productivity) level of the Baltic Sea and evaluate its long-term and seasonal variations. Since 1983 seasonal investigations of phytoplankton were carried out in a wide net of stations in the national (Lithuanian territorial and economic waters) and international (Baltic Proper) waters. The samples were taken from the surface water layer, also integrated samples from the depths 0,5; 2,5; 5,0; 7,5; 10; 15; 20 and 30 m were taken in the international stations. The analyses of chlorophyll a were performed according to methods recommended by HELCOM. The data are fully quality controlled. Systematic certification of laboratories, participation in international intercalibrations, internal control, introduced managing system for researches' quality, use of high quality reagents determine quality of data. All data is stored in archive (written form) and the data from 1992 also is saved on hard disk.

Department of Marine Research of the Environmental Protection Agency
Taikos Av. 26
Klaipeda

LT-91149
Lithuania