An additional burden on the ecology of the Sea of Marmara is also created by harmful emissions entering the Black Sea from the Danube.
Turkish President Recep Tayyip Erdogan has pledged to do everything possible to solve the problem of sea slime that has covered the shores of the Sea of Marmara near Istanbul.
A thick layer of brown phytoplankton slime threatens marine life and interferes with fishing.
This phenomenon was first recorded in Turkey in 2007, when it was also observed in the Aegean Sea off the coast of Greece. However, the current spread of slime in the Sea of Marmara has become the largest in history. The Turkish President said that the slime also threatens the ecology of the Black Sea.
"I hope that we will save our seas from this scourge of slime. I am afraid that it will spread to the Black Sea ... it will be a huge problem. We need to act immediately," Erdogan said.
He urged to investigate the causes of the phenomenon, linking it to the drainage of the sewer into the sea and the rising temperature of the water. The Turkish government has already sent a group of 300 people to study the situation.
Sea slime is a natural phenomenon that occurs when phytoplankton over-grow due to high temperatures and water pollution. According to experts, over the past 40 years, this problem has become more acute.
Ships in the Sea of Marmara have to sail through a thick layer of slime, some fishing boats cannot go out to sea because the slime clogs their motors and nets.
Since the sea surface is covered with mucus, fish and other representatives of the sea world die en masse from the lack of oxygen.
In an interview with the BBC, Professor Bayram Öztürk of the Turkish Center for Marine Research said the mucus problem will not go away unless the authorities invest more in a sewage cleaning program from Istanbul.
"The overgrowth of mucus threatens various marine organisms, including oysters, mussels and starfish. This is a real disaster," says the expert.
According to Turkish scientists, harmful emissions that enter the neighboring Black Sea from the Danube also create an additional burden on the ecology of the Sea of Marmara.