MOSCOW, May 4. /TASS/. The water of the World Ocean is becoming more and more acidified, thus posing a real threat to the oceanic inhabitants as skeletons and shells of marine organisms contain calcium, which is dissolved by the acidified water, Igor Semiletov, doctor of geography and the research director told TASS.
“Scientists discovered in the Arctic Ocean the unique mechanism of water acidification: as a result of permafrost melting, the ancient organic substance gets to the ocean in the form of carbon dioxide, which produces weak acid dissolving in the marine water. The acidification is additionally intensified because of Siberian rivers which desalinate water”, said Igor Semiletov, doctor of geography and the research director.
“As a result of more than ten-year work we have found out that there is another mechanism of water acidification on the East Siberian shelf. It differs from the one which changes water acidity in other areas of the World Ocean. Scientists have supposed before that such a mechanism could exist, but only our group have managed to prove the clear connection between warming, permafrost melting, river runoff, and acidification of the shelf water”, said Semiletov, the first author of the article published in the Nature Geoscience journal.
The rise of water acidification in the World Ocean is dangerous foremost because it dissolves calcium, which is contained in skeletons and shells of the marine organisms. Acidified water in tropical seas presents a real threat to coral reefs that consist of calcium, as well as to their inhabitants.
The acidification of water in the World Ocean has increased greatly during the previous century. Presumably, it happened because the carbon dioxide dissolves in saline water. It gets to the atmosphere as a result of industrial human activity. “During the years of industrial revolution from the end of XIX century, the acidification of the water in the World Ocean has increased by nearly 30%,” explained the scientist.
The Arctic Ocean absorbs carbon dioxide more actively than other oceans because it is the coldest one. When the temperature is low, carbon dioxide dissolves in water more quickly. Moreover, only the Arctic Ocean is surrounded by permafrost which degrades permanently.
The mass of the carbon dioxide in the form of the organic substance in the permafrost surrounding the Arctic Ocean is enormous. It exceeds the amount of carbon dioxide in the atmosphere by far. The permafrost is melting because of the warning in Arctic region, thus, it releases the ancient organic substance, which is involved in the modern cycle of carbon dioxide.
“Nevertheless, biogeochemical consequences of permafrost melting, connected with the acidification of shelf water of the Arctic Ocean, haven’t been studied until nowadays. It was supposed that the mechanism of water acidification in the Arctic Ocean was the same as the one in the other areas of the World Ocean and it was absorption of the carbon dioxide from the atmosphere. However, these conclusions were made without considering processes, taking place on the East Siberian shelf, and the corresponding data were not available,” explained Igor Semiletov.