A recent scientific study published in the Marine Pollution Bulletin reveals that the wreck of the World War I German minelaying submarine SM UC-30, which sank off the coast of Denmark in 1917, is continuously leaking toxic TNT and its degradation products into the North Sea. Conducted as part of the international NorthSeaWrecks collaboration, researchers detected chemical signatures in seawater, sediment, and marine wildlife such as blue mussels and starfish. While the pollution is currently localized, the corrosion of century-old steel hulls is exposing more explosives, posing significant toxic and carcinogenic risks to marine ecosystems and the food chain. With thousands of similar war wrecks and munitions dumps littering the North Sea and Baltic Sea, scientists emphasize the urgent need for continuous surveillance.
Environment Pulse Desk: A new scientific study claims a German U-boat that sank over one hundred years ago continues to seep toxic explosive into the North Sea, contaminating neighbouring waters, seabed and animals.
The wreck of the minelaying U-boat SM UC-30 lying off Rømø in Denmark The ship was returning to Germany after engine failure forced the mission to be abandoned when it hit a British mine on 19 April 1917. All 27 crew members died. The submarine sank with 18 sea mines and six torpedoes on deck, and was missing until a Danish diver found it in 2016.
Professors from Aarhus University Professor Katrine Juul Andresen has studied the site together with toxicologists at the University Medical Center Schleswig-Holstein in Germany and at Alfred Wegener Institute as part of an international collaboration called NorthSeaWrecks. Danish Navy divers collected seawater, sediment and marine samples such as blue mussels and starfish both from the wreck itself and its surrounding area.
The findings, reported in the Marine Pollution Bulletin, revealed the presence of chemical signatures from TNT and two degradation products — 2-ADNT and 4-ADNT — in water, sediments and wild animals.
“We discovered TNT residues in animal wildlife, on the ocean floor, and in the water column. “There is absolutely pollution happening, ” Andresen said.
TNT in seawater close to the wreck ranged around 72.6 nanograms per litre. It may not be a lot but it was enough to kill test mussels added to the wreck. The animals exhibited impaired detoxification systems, oxidative stress, metabolic perturbation and diminished energy reserves glycogen stores that are linked to the energy available for reproduction.
But for now, the pollution is fairly localised. But scientists warn it will get worse… More of the explosive inside the mines is getting exposed as century-old hulls corrode. TNT, as well as its degradation products, are both toxic and carcinogenic.
UC-30 is far from alone. The floors of the North Sea and the Baltic are littered with thousands of wrecks as well as munitions dumps from both the First and Second World Wars. There are over 10,000 wrecks charted in Danish waters alone with around 15 percent of that being from the two world wars. The risk of further leaks increases as their steel casings continue to corrode in the saline waters.
The researchers state that these submerged remnants require continuous surveillance The wrecks are war graves and artificial marine habitats, but they are also polluters that leach pollutants into the food chain — with implications for ecosystems as well as people who eat fish.
Also Read: Snow in the Atacama? Chile’s driest desert just turned white
