United Nations and scientists warn of extensive damage to Black Sea
One of the world’s great seas is spiralling into decline as a result of chronic over-fishing, high levels of pollution and the devastating impacts of alien species, an international team of scientists and the United Nations Environment Programme (UNEP) have concluded, calling for an international remediation effort.
The findings have come from a team from the newly-assembled Global International Waters Assessment (GIWA), a UNEP initiative. GIWA, which is assessing the environmental condition of 66 water systems across the globe, said that the Black Sea is under additional threat from large discharges of raw sewage, damaging levels of coastal erosion and dumped sludge and mud dredged from ports. Although the moves are underfoot to address some of the threats the scientists warn that rises in economic activity in the region may overwhelm any improvements by 2020 unless an extra, international, effort is made.
Pollution in the sea, which borders Russia, Ukraine, Turkey, Romania, Bulgaria and Georgia, but which has a catchment area covering 23 European countries, has contributed to a decline in oxygen levels, with pollutants from cities and factories from as far away as Germany present in its waters. At times levels at the bottom of the sea are so low that “it results in the deaths of all species of animals and plants,” the report notes. Eutrophication has seriously affected the sea with the report estimating that over 600,000 tonnes of harmful nutrients, the result of discharges from mainly household waste waters, industry and agriculture, are in the sea and that phosphorous levels are up to ten times in excess of maximum allowable pollution limits. “In the past 25 to 30 years the Black Sea has been transformed from a diverse ecosystem supporting varied marine life to a plankton one, with environmental conditions unsuitable for most organisms higher in the food chain,” the report reads, citing a 500% drop in dolphin numbers as an example of its effects.
Another threat to the sea is raw sewage pollution, as the vast majority of the sewage treatment works serving the area’s 162 million people, are substandard.
In the Russian part of the sea all current water treatment works in its 175 towns do not work properly, and in some towns there are no treatment works at all. Similar problems exist in virtually all coastal cities around the Black Sea, for example in no city along the Turkish Black Sea, the longest coast, is there any treatment of wastewater, and drinking water is often contaminated by polluted wastewater.
Pollution, the introduction of alien species, and over-fishing, including bottom trawling, have also decimated the sea’s main economic mainstay, fisheries. Stocks and wildlife have been affected by the centophore Mnemiopsis jellyfish, an imported species, whose weight is estimated to be 900 million tonnes, bigger than the entire global fish catch, with scientists believing it has played a role in the collapse of anchovy stocks. Total catches for all the nations bordering the sea fell from 814,000 tonnes in 1988 to 213,000 tonnes in 1991, but have since risen to 523,000 tonnes. However, only six of the 26 species commercially exploited in the 1960s remain in commercial quantities.
A $100 million scheme, involving the UN, the World Bank and the European Union targeted at the sea and two of the major rivers which drain into it, is expected to be up and running by the end of the year and will include work towards developing a nutrient protocol to the Black Sea Convention aimed at reducing the levels of phosphorous and nitrogen entering the sea. Another positive development is that the six countries bordering the Black Sea have established a joint naval force partly to protect the environment (see related story).
“We have known for some time that the Black Sea, a water system of global importance, has been suffering, but these results bring into sharp focus just how damaged it is and the risks to the millions of people who depend upon it for food and livelihoods,” commented Klaus Toepfer, UNEP’s Executive Director. “I hope these initial findings will galvanise the countries bordering and using the Black Sea to act while there is time.”
Another recent study of the Black Sea revealed that 89% of its waters are contaminated, and the main source of the pollution is the River Danube (see related story).