The Baltic sea was the largest dead zone

 

Satellite image: shows part of the Baltic sea with algal blooming. Dead zones in the Baltic basin increased more than tenfold over the last century, the researchers report. Thus, the reservoir is the world's largest oxygen-free zone of human origin.





 

In the period from 1898 to 2012 the anoxic areas of the Baltic sea has increased from 5000 to 60000 square kilometers. Swedish-Danish research team under the leadership of Jacob Carstensen from Aarhus University, conducted the surveillance, believes that the main culprit for dead zones is the water heating and a significant entry in the sea of various substances. From agricultural production, for example.

Scientists studied the area East of the Danish island of Bornholm and the Swedish island of Gotland, factors such as temperature, salinity and oxygen levels. They found: water temperatures in the surveyed areas have risen about two degrees Celsius. The consequences for the oxygen content are as follows: the higher the water temperature the less oxygen can dissolve in it. Another more serious reason is the flow of substances from agriculture, thanks to the flowing rivers. Cyanobacteria proliferate and consume oxygen. The researchers said that the Baltic sea is the largest anoxic zone of human origin.

 

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Source: nauka24news.ru/