Saline pulse brings relief to the main basin of the Baltic Sea

Even though we have for several consecutive summers now been able to enjoy clear waters, particularly in the eastern end of the Baltic Sea, the summer of 2015 was yet another reminder of the importance of cutting the nutrient load of the sea in a consistent manner. At the end of August, the Finnish Environment Institute (SYKE) reported on the results of the annual follow-up tours of research vessels Muikku and Aranda. The impact of the salty water inflow into the Baltic Sea in December 2014 can now be felt at the mouth of the Gulf of Finland.  According to the SYKE report, however, the effect of the inflow has now subsided, and it is not able to fully oxygenate the deep water masses, rich in hydrogen sulphide, of the Baltic Sea main basin. In the open sea area of the Gulf of Finland, the oxygen situation of the deep waters is better than last year, but the volumes of algae both in the Gulf of Finland and the Archipelago Sea exceed those of August 2014.  Moreover, in early September, the Finnish Environment Institute communicated that blue-green algal blooms, a sign of eutrophication, were larger in the open sea areas than they were last summer. As the beginning of the summer was windy and cold, the blooms did not develop before August. Read the SYKE release here.