DISTRIBUTION, DEVELOPMENT AND TOTAL AMOUNTS OF NUTRIENTS IN THE GULF-OF-FINLAND

Hydrographical parameters and nutrient concentrations have been measur ed from the year 1964 onwards in the Gulf of Finland. The development during 1964-92, and the recent distribution are discussed. Over the wh ole period, both for the dissolved inorganic nitrogen and the total ni trogen, an average upward trend of approximately 0.3 mu mol l(-1) was observed, corresponding to an increase of roughly 5500 tons of nitroge n annually in the water mass. However, both nitrate and total nitrogen concentrations trends have shown stabilized or even decreasing values for the last 4-5 years. According to the present budget evaluations, the nitrogen sinks and sources in the Gulf of Finland are roughly in b alance, in agreement with the observations of the recent years. This i s probably due to the weakening of the halocline, resulting in improve d oxygen concentrations in the Gulf of Finland, which affect the remov al processes of both nitrate and phosphate. For the Gulf of Finland, t he Baltic Proper functions as a sink for nitrogen and as a source for phosphorus. (C) 1995 Academic Press Limited