The oxygen situation was good in December-January in the Archipelago Sea and the Bothnian Sea, but oxygen problems continue in the Northern Baltic Proper and in the near-bottom water of the western Gulf of Finland. Phosphorus levels were high in all of Finland's sea areas. The observed concentrations in the Bothnian Bay were the highest ever recorded, and exceptionally high in the Bothnian Sea. Concentrations were also high in the Gulf of Finland, in some places almost reaching the highest levels ever recorded this time of year.
SYKE and the Finnish Meteorological Institute jointly monitor the state of the open sea
Water and sediment samples were taken on the cruise of the research vessel Aranda 17–29 January 2022, recording temperatures, salinity, oxygen levels, nutrients, and harmful substances such as pharmaceuticals. The sea areas that were monitored included the Gulf of Finland, the Archipelago Sea, the Northern Baltic Proper, the Bothnian Sea and the Bothnian Bay. The ice cover extent and ice properties were also surveyed in the Bothnian Bay. SYKE and the Finnish Meteorological Institute jointly monitor the state of the open sea. The monitoring is part of the monitoring programme of the Baltic Marine Environment Protection Commission (HELCOM) and the Finnish marine strategy. SYKE is responsible for chemical and biological monitoring and the monitoring of underwater noise, Finnish Meteorological Institute is responsible for physical monitoring.
Further information here.