Over 170 oil slicks pollute the Black Sea in a year

19.08.2025 | Ecology

A study by "Greenpeace" and SkyTruth revealed over 170 oil slicks, covering an area of 819 sq km, in the Bulgarian Black Sea, mainly due to discharged bilge water.

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A remarkable number of over 170 oil and ship fuel spills have been identified in Bulgaria's Black Sea waters over the last year. Data provided by the non-governmental organizations Greenpeace - Bulgaria and SkyTruth reveal the scale of the pollution, with a total area reaching a staggering 819 sq. km. The results of the analysis are summarized in an interactive map that is now available to the public. This was officially announced by the press center of Greenpeace - Bulgaria.

This large-scale assessment of pollution was made possible thanks to a modern monitoring system that uses satellite data from the Sentinel-1 satellite, part of the European Space Agency's fleet. The map documents and visualizes the oil slicks detected in the period from July 6, 2024, to June 26, 2025. It is important to note that it only depicts spills that have been double-confirmed by specialists from Greenpeace and Skytruth after a precise check with specialized software, as specified by Greenpeace - Bulgaria.

Causes and Consequences of Pollution

The experts from both organizations point out that the most common cause of the slicks is the discharge of bilge water, which is heavily contaminated with oil, ship fuel, chemicals, and heavy metals. This water collects in the lowest part of the ships, where the engine room is located. When unprocessed waste from the bilge is discharged directly into the sea, the oil spills onto the surface and forms visible slicks, leading to serious ecological consequences. Greenpeace - Bulgaria warns that these pollutants not only lower water quality but also disrupt the foundations of the marine food chain, posing a serious risk to marine animals and the entire ecosystem.

Martin Tomov, campaign coordinator for "Living Black Sea" at Greenpeace - Bulgaria, commented that these small but frequent oil slicks are often underestimated and do not receive the necessary attention, unlike large oil spills. According to him, this type of pollution is rarely recorded in official statistics, which makes it difficult to track and take adequate measures.

Protecting the Black Sea

In an effort to draw attention to the unique ecosystem of the Black Sea and to raise public awareness, at the beginning of December last year, Greenpeace - Bulgaria presented the documentary film "I, the Sea - Life in Silence". The purpose of the film is to show the general audience that the Black Sea is special, a home to unique species and habitats that need our protection and preservation.