Consequences of Climate Change: The Black Sea is Losing Its Habitable Waters and It's a Bad Sign
The makeup of the Black Sea is one of a kind, but its one that is fading astonishingly fast. Like many natural disasters in recent history, global warming plays its part in the decline.
The Unique Waters of the Black Sea
According to a report from the University of Liege, the geographical location of the Black Sea is behind its highly unique properties. Looking at this particular body of water at a map, one could almost mistake it as a lake. It's surrounded by land by all sides, making its main source of water the rivers, which pours in fresh water. It does, however, get its fair share of salt water through Bosphorous Strait, a one-kilometer-wide waterway connecting it to the Mediterranean Sea.
Arthur Capet, first author of the publication on the decline of oxygen in the Black Sea and researcher at MAST, explained that fresh water settles in the upper layers of the body of water without mixing with the denser salt water of the lower layers. Furthermore, permanent stratification keeps the deep waters of the Black Sea deprived of oxygen and marine life tends to develop above this imaginary line.
"The oxygenated and therefore habitable area of the Black Sea is a very restricted space," Capet said, adding that this makes the sea sensitive to rapid change. "This is the case horizontally, because the basin is almost completely closed, and also vertically, owing to this permanent stratification."
Shrinking of the Habitable Area
The change did, indeed, come quickly. Through data collected in the past 60 years, Capet discovered that the oxygen-rich top layer of the Black Sea decreased from 140 meters to 90 meters deep, which amounts to an over 40 percent dip in habitable waters.
The report stated two existing causes behind the shrinkage: an abundance of nutrients - particularly algae that led to great consumption of oxygen -- and global warming. With warmer winters, there is a lower volume of dense water created and this lowers the oxygen content. Warmer waters also mean the sea is now able to accumulate less dissolved gas, including oxygen.
"There will be an ecological and economic affect," Capet warned. "Fishing, which is one of the major activities in the region, will probably have to adapt to this reorganisation."
So while species above the Black Sea are thriving -- a report from Daily Sabah revealed the rare northern warbler has been spotted and photographed for the first time - the marine life and the people around it may soon feel the effects of the changes.