page_title: Baltic Sea
section_title: Environmental status
hierarchical_section_title: Baltic Sea / Biology / Environmental status
context_page_description: The Baltic Sea is an arm of the Atlantic Ocean, enclosed by Denmark, Estonia, Finland, Latvia, Lithuania, Sweden, northeast Germany, Poland, Russia and the North and Central European Plain.
  The sea stretches from 53°N to 66°N latitude and from 10°E to 30°E longitude. A marginal sea of the Atlantic, with limited water exchange between the two water bodies, the Baltic Sea drains through the Danish Straits into the Kattegat by way of the Øresund, Great Belt and Little Belt. It includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga and the Bay of Gdańsk.
  The Baltic Proper is bordered on its northern edge, at the latitude 60°N, by the Åland Islands and the Gulf of Bothnia, on its northeastern edge by the Gulf of Finland, on its eastern edge by the Gulf of Riga, and in the west by the Swedish part of the southern Scandinavian Peninsula.
  The Baltic Sea is connected by artificial waterways to the White Sea via the White Sea-Baltic Canal and to the German Bight of the North Sea via the Kiel Canal.
context_section_description: Satellite images taken in July 2010 revealed a massive algal bloom covering 377,000 square kilometres (146,000 sq mi) in the Baltic Sea. The area of the bloom extended from Germany and Poland to Finland. Researchers of the phenomenon have indicated that algal blooms have occurred every summer for decades. Fertilizer runoff from surrounding agricultural land has exacerbated the problem and led to increased eutrophication.
  Approximately 100,000 km² (38,610 sq mi) of the Baltic's seafloor (a quarter of its total area) is a variable dead zone. The more saline (and therefore denser) water remains on the bottom, isolating it from surface waters and the atmosphere. This leads to decreased oxygen concentrations within the zone. It is mainly bacteria that grow in it, digesting organic material and releasing hydrogen sulfide. Because of this large anaerobic zone, the seafloor ecology differs from that of the neighboring Atlantic.
  Plans to artificially oxygenate areas of the Baltic that have experienced eutrophication have been proposed by the University of Gothenburg and Inocean AB. The proposal intends to use wind-driven pumps to inject oxygen (air) into waters at, or around, 130m below sea level.
  After World War II, Germany had to be disarmed and large quantities of ammunition stockpiles were disposed directly into the Baltic Sea and the North Sea. Environmental experts and marine biologists warn that these ammunition dumps pose a major environmental threat with potentially life-threatening consequences to the health and safety of humans on the coastlines of these seas.
caption: Phytoplankton algal bloom in the Baltic Proper, July 2001
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