Experts warned that the oxygen-free layer at the bottom of the Marmara Sea is gradually leaning towards the surface, and the failure to prevent the increasing pollution will be a disaster for the Marmara Sea.
According to the data of the Middle East Technical University (METU) Marine Sciences Institute, the oxygen value in the first 30-meter layer of the Black Sea water in the Marmara Sea was measured as 8-9 milligrams per liter.
It decreases to 1 to 2 milligrams in the Mediterranean water starting from 30 meters, and below 1 milligram in the layer up to 300 meters from the bottom of the sea.
According to the long-term data compiled by the Marmara Sea Integrated Modeling System (MARMOD) Project conducted by METU with the Ministry of Environment, Urbanization and Climate Change for the deep waters of the Çınarcık Pit in East Marmara, oxygen values that were above 2 milligrams per liter in the 1980s. Today, it has dropped below 0.5 milligrams per liter.
Prof. Dr. Barış Salihoğlu, Director of METU Marine Sciences Institute, stated that the Marmara Sea is very important socioeconomically as it is the transition point of the Mediterranean and Black Sea waters, which are very different from each other physically and ecologically.
Expressing that the effects of the Black Sea are very visible in the Marmara Sea, Salihoğlu said that this pressure has decreased with the control of the pollution from the Danube River, while the pressure of the cities surrounding the sea has increased.
“MARMARA TURNED INTO A SICK SEA”
Salihoğlu continued as follows:
"As a result, Marmara turned into a sick sea. Below 25 meters, oxygen does not allow life. It's almost anoxic right now. This indicates that the summer conditions at sea will be very bad. Oxygen has been reset in a layer at 28 meters, there is obviously a serious organic accumulation just below the oxygen layer above, and this has decomposed to zero oxygen. If we halve the pollution today, we see that the water coming from the Mediterranean and feeding the Marmara will raise the oxygen levels above the hypoxic level that we aim for in 5-6 years. If the water coming from the Mediterranean is reduced or its pollution increases, it will be a disaster for Marmara. It quickly returns to the Black Sea."
THE RIVERS FLOWING TO MARMARA ARE VERY DIRTY
Salihoğlu underlined that all treatment systems should switch to advanced treatment as soon as possible and 11 rivers flowing into the sea should be cleaned so that the worst possible scenario does not happen.
"The rivers flowing into the Marmara are very polluted, and there is a serious pollution input from the Susurluk Basin. If these increase, Marmara may turn into a dead sea. It's in bad shape right now, I hope we don't get to a much worse point," he added.