Commitment to the Black Sea

Geographical information | The unique environment | Averting the crisis | Pollution problems

Geographical information

 Black Sea map

The Black Sea is a natural inland water basin situated between Europe and Asia. Six countries share the Black Sea coast: Bulgaria, Georgia, Romania, Russia, Turkey and Ukraine. The lengths of their respective coastlines are: Bulgaria — 354 km, Georgia — 310 km, Romania — 225 km, Russia — 800 km (including the Azov Sea), Turkey — 1329 km and Ukraine — 2782 km (including the Azov Sea). A population of about 16 million people inhabits the coastal zones of the six countries.

The following are some of the basic geographical characteristics of the Black Sea: total area — 422 000 sq km (441 000 sq km including the shallow Azov Sea), maximum depth — 2212 m, average depth — 1300 m, volume — 540 000 cubic km, wave height up to 6 — 7 m, wave length up to 90 — 100 m, tidal variations — 3 to 10 cm, average winter temperature of seawater - 4°C, average summer temperature of seawater — 22—24°C. The largest bays on the Black Sea are the Karkinitski, the Bourgas, the Kalamitski, the Dnieprovski, the Dniestrovski, the Sinop and the Samsun Bay. The largest rivers flowing into the Black Sea are the Danube, the Dnieper, the Don, the Dniester, the Kuban, the Southern Bug, the Rioni, the Kizil—Irmak and the Kamchia rivers.

The unique environment

The Black Sea with its total area of roughly one third the size of continental Europe is one of the largest inland water basins in the world. It is almost entirely isolated from the world's oceans but is over 2 km deep in places and receives river inputs from a large catchment territory, including major parts from seventeen countries and the second, third and fourth largest rivers in Europe, respectively the Danube, the Dnieper and the Don.

The Black Sea is connected to the Mediterranean only through the narrow and winding Bosphorus Straits, a 35-km natural channel, as little as 40 m deep and 700 m wide in places. It leads to the Sea of Marmara and then to the Aegean Sea through the Dardanelles. This complex natural system makes the replenishment of seawater in the Black Sea very slow.

Every year the rivers pour an average of 350 cubic km of water into the sea and since it receives more fresh water than it loses from evaporation, the average salinity is quite low — 18‰. The surface outflow, a mixture of seawater and fresh water, from the Black Sea to the Aegean amounts to about 610 cubic km annually. To compensate for this loss of water, the Black Sea receives an inflow from the Mediterranean with higher salinity but the volume is roughly twice smaller. It enters the sea as an underflow through the Bosphorus, which also carries the outflow. The two do not mix very easily and as a result the Black Sea has got a surface layer about one hundred metres deep which contains more fresh water than the waters below.

The replenishment of the bottom waters of the Black Sea with new seawater from the Mediterranean takes hundreds of years. This very slow rate of replenishment and the large input of freshwater have led to a stratification of the Black Sea that has now got a lighter and fresher upper layer and a denser underlying layer.

The slow replenishment and the bad mixing of waters does not provide enough oxygen for the process of decomposition and the bacteria in the lower layers use it up entirely. Consequently the Black Sea is virtually dead below a depth of about 180 metres and this boundary is being pushed up. Moreover the metabolism of some bacteria generates hydrogen sulphide, a soluble poisonous gas associated with the smell of rotten eggs. Hydrogen sulphide is present in the entire lower layer of seawater in the Black Sea.

Therefore the Black Sea is now the largest natural anoxic water basin in the world. This means that 87 % of its volume is practically devoid of marine life, except for some forms of bacteria. However, the Sea is still comparatively rich in living resources. Also, the Black Sea shelf and river deltas are important spawning grounds for sturgeon and other fish species, and the coastal wetlands are migration and breeding grounds for numerous rare and endangered European birds. The warm coastal waters and sunny beaches of the Black Sea, the beauty of its shorelines, plains and mountains attract millions of tourists.

Averting the crisis

Photo: © C.Laycock

Environmental issues and the protection and rehabilitation of the Black Sea are of great interest for the coastal population. In recent time the entire Black Sea environment has suffered a major and very evident decline. The sea has been used for fishing, tourism, mineral extraction and marine transport and as a convenient dumping place for solid and liquid waste. The large influence of the land and the intensive use of the sea by shipping suggested that pollution was the cause of the decline. It was also clear that this pollution was the result of the human activities in all coastal countries and if the crisis was to be averted, the issue had to be addressed jointly.

The legal framework for regional cooperation was elaborated after the 1972 Stockholm Conference on Environment and Development. In the early 1990s representatives of the six Black Sea countries drafted their own Convention for the Protection of the Black Sea against Pollution, signed in Bucharest in 1992 and ratified by the six national assemblies by early 1994. The Bucharest Convention, includes a general framework of agreement and three specific protocols: on the control of land-based sources of pollution, on the dumping of waste and on joint action in the case of accidents, such as oil spills. The implementation of the Convention is overseen by a Commission with a permanent Secretariat based in Istanbul, hence the Istanbul Commission.

Another important step in the regional process was the Ministerial Declaration on the Protection of the Black Sea Environment, signed by the six environmental ministers in Odessa in 1993. Shortly after, the countries requested support to develop a long-term Action Plan. With $ 9.3 million in funding provided by the Global Environmental Facility (GEF) and collateral international donors, the Black Sea Environmental Programme (BSEP) was launched in 1993. BSEP successfully provided the missing link between experts on Black Sea and environmental issues in the separate countries. One of the basic problems was the provision of reliable information on the state of the environment itself. Such information is vital for the improvement of environmental policy and for long-term policy development and actions, including investments. BSEP established an operating network of 40 institutions in the Black Sea region, which assisted the coastal states and the NGO community in developing regional-based action plans and capacities for better managing the Black Sea environment.

BSEP has invested heavily into recruiting experts and improving the pollution monitoring network. The working parties prepared national and regional thematic reports presenting the available information and analysis to scientists, managers and policy makers. The Transboundary Diagnostic Analysis (TDA) carried out under the GEF project, led to development of the Black Sea Strategic Action Plan (BS-SAP) adopted by the six coastal states in Istanbul in 1996. Both documents explain causes for the environmental crisis of the sea and suggest solutions.

In June 2002, the BS-SAP was revised by the six countries, which reconfirmed their commitment to the original document. Currently the UNDP-GEF Black Sea Ecosystem Recovery Project (2002-2004) is underway, addressing basin wide eutrophication issues through reform of agricultural policies, improved municipal and industrial wastewater treatment, rehabilitation of key basin ecosystems and strengthening the legislative framework.

Pollution problems

  1. The most significant process causing degradation of the Black Sea as far as pollution is concerned has been the massive over-fertilisation by nitrogen and phosphorus compounds, coming largely from agricultural, domestic and industrial sources. This phenomenon called eutrophication has changed the entire Black Sea ecosystem. The compounds enter the sea from sources in the 17 countries in its drainage area. The coastal countries contribute roughly 70% of the total amount and almost all the remaining amount enters the sea via the Danube River.
  2. Discharge of insufficiently treated sewage: introduce microbiological contaminants into the Black Sea and pose a threat to human health and in some cases hamper the development of sustainable tourism and aquaculture. The discharge is estimated at about 571 million cubic metres annually.
  3. Oil pollution. Oil enters the sea as a result of operational discharges of vessels and accidents, as well as through land based sources. Oil pollution levels are not high in the open sea but are unacceptable in many coastal areas. Annually some 95 000 tons of unrecoverable oil waste is discharged into the Black Sea. Toxic substances such as pesticides and heavy metals do not appear to pollute the whole sea but appear in 'hot spots' near certain well-identified sources. These polluters are usually associated with heavy industry and with the economic decline in the region their use has decreased considerably.
  4. Radioactive substances have been introduced to the Black Sea in small quantities from nuclear power generation and as a result of the Chernobyl accident in 1986.
  5. Uncontrolled deballasting from ships has introduced to the Black Sea exotic species, brought from other parts of the planet and flourishing in the new environment. Some of them have proliferated becoming predators to the indigenous species thus damaging the Black Sea ecosystem.
  6. Solid waste dumped into the sea from ships and coastal towns. As an enclosed sea, the Black Sea is particularly vulnerable to this kind of pollution as any floating or half-submerged waste is inevitably washed ashore. Some beaches have a high accumulation of garbage presenting a risk to marine animals and humans.

The BS-SAP recommends preventive measures to control pollution. Anticipatory action is an underlying principle of the Plan, though it employs the 'polluter pays' principle as well. The Plan calls upon the signatories to agree on common water quality objectives and develop a strategy of gradual step-by-step reduction of loads until the objectives are reached. Places where pollution levels are unreasonably high called "hot spots" are regarded as immediate priorities for action. The Action Plan not only addresses pollution entering the sea from rivers and discharge pipes but also includes detailed provisions for preventing pollution from ships, for minimizing pollution from maritime accidents and controlling illegal dumping of waste into the sea. Another important provision on pollution concerns future monitoring of the state of the Black Sea.