СЕЗОННАЯ ИЗМЕНЧИВОСТЬ ПЕРВИЧНОЙ ПРОДУКЦИИ И СОСТАВА ФИТОПЛАНКТОНА В БЕРЕГОВОЙ ЗОНЕ РОССИЙСКОГО СЕКТОРА ГДАНЬСКОГО БАССЕЙНА БАЛТИЙСКОГО МОРЯ

Abstract

From April 2008 to until April 2009 we investigated the seasonal dynamic of primary production in the coastal zone of the south-eastern Baltic Sea. The predominant limiting factor for diatoms and dinoflagellates spring bloom was nitrate. During the nitrate-limited period, increase of ammonium due to mineralization of organic matter can temporarily change the prevailing N-limitation for phytoplankton grow into a P-limited phase. Nitrate and phosphate concentrations reached minimum values in mid-summer, almost below detection limits (0,07 mmol/m3 NO3, 0,06 mmol/m3 PO4). Moderate influence of continental run off with the peak runoff during of the spring-summer minimum of phytoplankton grow on primary production was observed: its annual value reached to the eutrophic level (290 gC·m-2·year-1), however the seasonal dynamic type was typical for mesotrophic waters of northern middle latitudes.