On the last day of October, the six Black Sea states, Bulgaria, Romania, Ukraine, Russia and Turkey, mark the day of the common sea.

October 31 is the date on which, during 1996, the coastal states adopted a strategic action plan for the renewal and preservation of the Black Sea.

Connected to the Mediterranean and the Sea of ​​Marmara through the Bosphorus and Dardanelles straits, the Black Sea is one of the slowest-flowing bodies of water in the world.

Much of its depths are filled with sulphur, which has expelled life in over 85 percent of its volume.

Only the top 10-15 percent layers from this sea are still "alive". To them extends the kingdom of anaerobic organisms and archaeological waste from some ancient civilizations, well preserved by sulfur compounds.

They call him black because of his character. But maybe also because of the poorer transparency of the waters, on average about five meters, in contrast to the Mediterranean neighbor, where the view can penetrate below 30 meters deep.

The Black Sea is much less salty than the Mediterranean, because the waters of the four largest European rivers, the Danube, the Dnieper, the Dniester and the Don, flow into it. The water catchment includes 21 states. 2000 species of animals and about 1000 species of plants live there.

During the 60s of the last century, the process of a rapid loss of biological diversity began in the pond, and today fish are very few.

International Black Sea Day aims to draw society's attention to threats to the sea, such as pollution, fishing and construction in coastal regions.