The coastal areas of the Baltic Sea have experienced an “unprecedentedly serious” loss of oxygen over the past hundred years. To this conclusion came the Finnish and German scientists. The study is published in the journal Biogeosciences, briefly reported by the European Union of Earth Sciences.
Specialists have found that the last period of deoxygenation (loss of oxygen) in the Baltic Sea began not in the 1950s, as previously thought, but in the 1900s. At the same time, the process, conditioned by human factors, was especially intense at the end of the 20th century.
The authors came to similar conclusions after studying the four-meter core extracted from the bottom of the Archipelago Sea (part of the Baltic Sea between the Botnic and the Gulf of Finland). The investigated sample allowed to estimate fluctuations of oxygen in the region for the last 1,5 thousand years.
Experts note that anthropogenic load is the main cause of de-oxygenation of the Baltic Sea during the last hundred years. Scientists admit that, despite the reduction in human exposure that has occurred in recent years, the oxygen content in the water has practically not increased. The reason for this is seen in global climate change. Under such conditions it is possible to significantly reduce deoxygenation, according to experts, an even greater reduction of anthropogenic load.