Baltic Proper, Gdansk Basin, Bornholm Basin, Arkona Sea, Gotland Basin, Landsort Deep, Faro Deep during the period 1972 - 1992 (data set limits: 54 53 - 59 23N; 13 23 - 22 11E). Baltic Proper, Gdansk Basin and Gotland Basin during the period 1993 - 1999 (data set limits: 54 53 - 57 22N; 18 24 - 20 20E). Baltic Proper since 2000 (data set limits: 55 31 - 56 05N; 19 14 - 20 39E).

Ammonium and ammonia concentration parameters in water bodies; Nitrate concentration parameters in the water column; Nitrite concentration parameters in the water column; Phosphate concentration parameters in the water column; Silicate concentration parameters in the water column

CTD; discrete water samplers; spectrophotometers; nutrient analysers

The purpose of the research is to evaluate the Baltic Sea hydrochemical state, it's changes and influence to water quality, phytoplankton abundance and biodiversity. Systematic research of the Baltic Sea was carried out by Lithuanian research vessels 'OKEANOGRAFAS', 'VEJAS' and 'VETRA'. Since 1979 the research of the Baltic Sea has been carried out according to the Lithuanian and Helsinki Commission (HELCOM) monitoring programme. Since 1972 hydrochemical investigations have been carried out in a wide net of stations in national and international waters (including Baltic Proper, Gdansk Basin, Bornholm Basin, Arkona Sea, Gotland Basin, Landsort Deep and Faro Deep), later the net of stations became more narrow and since 2000 research in the Baltic Sea has been defined more exactly and has been carried out only in the exclusive economic zone of Lithuania. Nutrient investigations are carried out during every season at a constant network of stations in standard sea water horizons. In 1972-1992 research was performed at 35 stations, 1993-1999 - 14 stations and since 2000 - 5 stations. Hydrochemical data is stored in archive (in table forms on paper) and is saved on hard disk with research time, stations, depth series.

A.Jasinskaite (2008) Nitrogen and phosphorus in the Curonian Lagoon and Baltic coastal zone / Monograph: The Baltic Sea and its problems (Articles in Lithuanian with English summaries), N.Remeikaite, R.Nikzentaitiene; Wasmund N., Nausch G., Postel L., Witek Z., Zalewski M., Gromisz S., Lysiak-Pastuszak E., Olenina I., Kavolyte R., Jasinskaite A., Muller-Karulis B., Ikauniece A., Andrushaitis A., Ojaveer H., Kallast (2000) Trophic status of coastal and open areas of the south-eastern Baltic Sea based on nutrient phytoplankton data from 1993-1997. Baltic Sea Research Institute Warnemunde, Marine Science Reports No. 38 (2000)., ; Wasmund N., Andrushaitis A., Lysiak-Pastuszak E., Muller-Karulis B., Nausch G., Neumann T., Ojaveer H., Olenina I., Postel L., Witek Z. (2001) Trophic status of the south-eastern Baltic Sea: a comparison of coastal and open areas. Estuarine, Coastal and Shelf Science, Academic Press 2001.,

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

LT-91149
Lithuania