RMF242 days agoEnvironment2 min read

Norway investigates the wreck of U-864 with mercury at the bottom of the North Sea

Quick Look

The wreck of the German submarine U-864 from World War II, which sank in 1945 near the Norwegian island of Fedje, lies at a depth of 150 meters with a load of 65-67 tons of mercury.
In May 2025, the Norwegian Coastal Administration conducted a detailed examination of the wreck using an ROV and 4K cameras, creating a 3D model.
In 2026, an attempt was made to extract the cargo - 22 containers were recovered, 80% of which were damaged, which resulted in some mercury entering the water during the operation.

AI-generated summary

Why It Matters

The submarine U-864 was sunk by the British HMS Venturer in February 1945 during World War II. This was the only case in history of a submerged submarine being sunk by another submerged ship. It carried a cargo of mercury intended for the Japanese arms industry.

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At a depth of about 150 meters, just off the Norwegian island of Fedje, the wreck of the German submarine U-864 has been lying for over 80 years. It sank during World War II, broken into two pieces after being hit by a torpedo by the British ship HMS Venturer. This was the only time in history that a submerged submarine sank another submerged ship. Along with U-864, 73 crew members and extremely dangerous cargo went to the bottom - hundreds of containers of mercury.

Toxic load

According to historical documents, there were up to 1,867 containers of mercury on board U-864, intended for the Japanese arms industry. It is estimated that it could have been from 65 to 67 tons of this poisonous substance. Although the exact amount is unknown, one thing is certain - a significant part of the mercury is still in the wreck.

Mercury is an element that does not biodegrade and can survive in the environment for hundreds of years. Particularly dangerous is its organic form - methylmercury - which is produced as a result of the action of microorganisms and accumulates in the food chain, especially in fish. It is this aspect that causes the greatest concern among ecologists and residents of the region.

In May 2025, the Norwegian Coastal Administration conducted a detailed examination of the wreck using remotely operated underwater vehicles, 4K cameras and advanced measurement techniques. As a result, a three-dimensional model of the wreck and the surrounding seabed was created. It turned out that many mercury containers were damaged when the ship sank, and some of the substances could have penetrated into the sediments.

The dilemma of the Norwegian authorities

In 2026, the Norwegian services attempted to recover part of the cargo. 22 containers were recovered from the wreck, 80% of which it was damaged and leaking. About half a ton of mercury reached the surface, but during the operation some of the substance entered the water.

What to Watch

AI outlook — possibilities, not facts

Norway will carry out further examination of the U-864 wreck to assess the condition of the mercury containers and the risk of further leakage.
Likely · Within months
The decision on the future of the U-864 wreck (excavation vs. leaving it at the bottom) will be made after analyzing the results of the 2026 operation and further environmental research.
Likely · Within months

Open Questions

What is the exact amount of mercury still in the wreck?
Are further mining operations technically feasible without the risk of contamination?
What are the long-term ecological impacts of potential mercury leakage into the food chain?
Is Norway considering leaving the wreck at the bottom with monitoring as an alternative to mining?