|V-1302 John Mahn was lost in the Belgian North Sea. VLIZ|
The V-1302 John Mahn, a German warship sunk in 1942, is currently leaking toxic chemicals and heavy metals in the North Sea.
A second-world-war shipwreck is leaking hazardous chemicals into the North Sea, including explosives and heavy metals, implying that other wartime wrecks may need to be removed from the seafloor.
The V-1302 John Mahn was a fishing trawler commandeered by the German navy during WWII and sunk by British bombers in 1942. Since then, it has lain 30 meters below sea level in the Belgian North Sea.
Josefien Van Landuyt of Ghent University in Belgium and her colleagues have now found traces of arsenic, explosives, and heavy metals such as nickel and copper in samples taken from the boat's steel hull and the surrounding ocean floor. The team also discovered (PAHs), a class of chemicals found naturally in fossil fuels.
"We discovered that the concentration of PAHs increases as you get closer to the ship, particularly the coal bunker," Van Landuyt says.
These chemicals, she claims, are reshaping the microbiome in the ship's immediate vicinity, with known PAH-degrading microbes like Rhodobacteraceae and Chromatiaceae found in samples with the highest pollution levels.
According to Van Landuyt, the pollution caused by the V-1302 John Mahn is minor, allowing the wreck to continue to function as an artificial reef and fish nursery.
However, she warns that thousands of other wrecked ships and aircraft from the time period could be leaking larger amounts of toxic materials into the North Sea. Little is known about their location on the seafloor or what they were carrying.
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"Some of these ships... were hit while still loaded with munitions," she says.
Van Landuyt's research is part of the North Sea Wrecks project, which will make a recommendation later this year on whether wartime wrecks should be removed from the seabed to protect marine life.
According to Andrew Turner of the University of Plymouth in the United Kingdom, if nothing is done, the wrecks could continue to pollute for decades. "Whether it's anti-fouling paint, electronics, or coal PAHs, they'll last a long time." The PAHs at the sea's bottom will take decades to degrade."