NASA Earth Observatory image modified by SkyTruth

Investigating the Overlooked Culture of Illegal Bilge Dumping in Europe’s Seas


Cerulean Case Study

Investigating the Overlooked Culture of Illegal Bilge Dumping in Europe’s Seas

SkyTruth collaborated with a team of journalists and media outlets led by investigative newsroom Lighthouse Reports to inspect the problem of chronic (and often illegal) oil pollution by vessels transiting European waters. Although Europe is not as affected by oil dumping as other regions, SkyTruth’s investigation revealed the actual number of pollution events to be much higher than the statistics officially reported by the European Maritime Safety Agency (EMSA).

“Using satellite imagery and machine learning provided by the environmental watchdog SkyTruth, we found hundreds of potentially illegal oil dumps by shipping vessels and oil tankers in European waters since 2020.”

European authorities reported 32 slicks in 2019. SkyTruth estimated the actual number to be closer to 3,000 annually (the equivalent of eight spills per day), based on the satellite imagery analyzed by Cerulean.

Bilge water is a melange of toxic substances such as lubricants, cleaning solvents, and metals that accumulate at the bottom of a vessel. Treating the collection of hazardous waste is expensive, and many ships opt instead to dump the oily bilge water into the ocean, despite the serious threat this poses to marine life and coastal communities.

Countries should respond quickly if vessels are found to be dumping illegally. However, this six-month investigation found responses to be lethargic and the prosecution insubstantial, fostering a culture of impunity.

EMSA tracks marine spills through its CleanSeaNet platform, which uses satellite imagery to monitor and prevent possible bilge dumping incidents. If an incident is detected, an alert is sent to the responsible country to inspect and report its conclusion to EMSA, but the Lighthouse Reports investigation showed that few received any follow-up.

“This is a problem that’s been invisible to the public,” John Amos, CEO of SkyTruth, told the UK Guardian in their coverage of this report. “You can give governments all the best tools in the world but if there’s no public accountability and pressure for them to use those tools, problems will not get fixed.”

Whistleblowers revealed a culture onboard ships that encourages dumping, including methods to release bilge water that lower the chances of discovery, such as dumping at night or in rough seas. According to the UK Guardian coverage of the report, a ship engineer reported to the investigation that a chief engineer had told him, “Be quiet, do not speak out. If you speak then it is very much trouble for you.” His job was terminated after he confronted the engineer.

Given the inconsistent and often inconsequential enforcement of regulations addressing oil pollution, Cerulean provides an outlet for the public to monitor the bilge dumping crisis themselves. Now, agencies like EMSA are no longer the only voice reporting on oil dumping, leading to greater transparency and ultimately less pollution from the growing number of cargo ships and tankers plying the ocean.

Further Information

Satellite image of a bilge discharge in the North Sea.
Example of bilge discharge by a vessel passing through the North Sea in May 2023. Graphic © SkyTruth, containing satellite imagery © 2023 Planet Labs Inc.