German navy oil hunters mark 40 years of policing North and Baltic Sea pollution

Four decades of aerial patrols

Since 1986, two Dornier 228 LM aircraft have flown daily over the North and Baltic Seas, monitoring for oil and other marine pollution. The twin-engine planes, designated "LM" for "Luftüberwachung für Meeresverschmutzung" (air surveillance for marine pollution), are operated by Marinefliegergeschwader 3 "Graf Zeppelin" from Nordholz in Lower Saxony. The blue-and-white aircraft carry "Pollution Control" in large letters on both sides of the fuselage. Germany is obligated to monitor its waters under the MARPOL agreement of 1973, the international convention on marine pollution prevention. Findings are forwarded to the Havariekommando in Cuxhaven, a joint institution of the federal government and the coastal states. Other maritime nations conduct similar patrols.

Technology and tactics

The aircraft fly at 600 meters over the sea, equipped with side-looking radar that scans up to 40 kilometers on each side under optimal conditions, plus cameras and sensors. Operator Kevin, a 36-year-old technician, explained that oil slicks deflect radar beams rather than reflecting them, appearing as black spots on the radar image. The radar functions at night, countering ships that have tried to discharge under cover of darkness. Kevin noted that the crew does not need to catch every violator in the act, since pollution can remain on the surface depending on wind and wave conditions.

There have been ships that bet on: if they discharge at night, we won't see them. But the radar works at night too.

During one patrol south of Denmark's coast, pilot Benjamin spotted a freighter and directed the aircraft toward it. Operator Kevin examined the live camera feed, observed water flowing from the deck, and determined it was seawater used for cleaning, which is permitted. No violation was recorded.

Declining pollution rates

The Havariekommando reports a steady decline in pollution over four decades. In the 1980s, a pollution incident was detected every 3 to 4 flight hours, roughly once per patrol. By 2025, that interval had stretched to every 11 to 12 flight hours. Benedikt Spangardt, spokesperson for the Havariekommando, attributed the decline to the deterrent effect of the patrols.

We see that the numbers of pollution have simply been continuously declining for 40 years.

Spangardt compared the deterrent effect to speed cameras on highways.

People know there are checks, there can be consequences. Then I might think twice about whether I do something illegal or not.

2025 figures

In 2025, 130 environmental pollution incidents were recorded across the North and Baltic Seas. Possible perpetrators were identified in 37 percent of cases. The detected pollution included oil and unknown substances, which can originate from tank washing and drilling water at sea. Evidence collected by the naval aviators is handed to investigating authorities by the Havariekommando.

The German Bight sees more than 120,000 ship movements annually, making it one of the most heavily trafficked waterways in the world, according to the Wasserstraßen- und Schifffahrtsverwaltung.