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Scientists travel from Bremerhaven to the wreck of the “SMS Mainz” on the research ship “Heincke”
Photo: Annica Müllenberg / dpa
The Heligolanders have not had good experiences with ammunition from the World War.
In April 1947, the British detonated thousands of tons of grenades and explosives on the German offshore island - much of them had been in underground military facilities of the Wehrmacht.
At that time, the "Big Bang" was considered the largest non-nuclear explosion in world history.
A research team headed by the German Maritime Museum (DSM) now wants to find out what the condition of the old ammunition is, which is still distributed around the island in the sea.
It is not only about the danger of explosions, but also about the environment.
The destination of the expedition, for which ten scientists set off from Bremerhaven on Thursday, is the naval cruiser "SMS Mainz".
It was sunk in 1914 by British warships west of Heligoland during the First World War.
On the one hand, the researchers want to take samples from the wreck in order to analyze the possible dangers posed by the old weapons.
For this purpose, mussels are to be released in the deep.
In three months the animals will be collected again and examined for toxicological substances.
The aim is to check whether carcinogenic substances such as TNT and its breakdown products can be detected in the investigation area.
According to estimates by the Federal Environment Agency (Uba), there are around 1.6 million tons of ammunition from World War II in the German North and Baltic Seas.
Around 5,000 tons of chemical warfare agents were sunk in the Second World War alone by military operations or afterwards by dumping, most of them in the Baltic Sea.
But dozens of tons of chemical ammunition also disappeared in the Helgoland hole in the North Sea.
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Navy cruiser "SMS Mainz": Sunk west of Heligoland in 1914
Photo by Arthur Renard / Naval History and Heritage Command
Due to ocean currents and bottom-trawling, mines and bombs landed in places where they should never be.
That makes it difficult to find them again today.
When building new pipelines or offshore wind farms, it is not uncommon for companies to come across such weapons.
Liver tumors in flatfish
Under water, the metals in the ammunition bodies of bombs, mines and grenades begin to rust and the explosives and weapons are released into the sea.
The list of chemical pollutant compounds is long.
TNT, in particular, is classified as dangerous because the agent releases toxic, carcinogenic and mutagenic substances into the water.
Heavy metals such as mercury are also released.
The substances could be absorbed by fish and mussels and thus get into the food cycle.
The Thünen Institute of Fisheries Ecology, for example, examined the flatfish dab that lives on the seabed in the Bay of Kiel, an area that contains thousands of tons of conventional ammunition.
The researchers found liver tumors in 25 percent of the specimens.
In unpolluted areas, on the other hand, the rate is only five percent.
Overall, little is known about the effects of the contaminated sites on marine organisms and ultimately also on humans.
The “North Sea Wrecks” project under the direction of the Maritime Museum is now supposed to provide answers to such questions.
An exhibition is also planned, which will present the first results from August.
Politicians are also concerned with the correct way to deal with old World War II ammunition.
At the end of last year, the Greens and the FDP announced that they would campaign for a rescue program for the federal government.
The parliamentary groups of both parties want to submit a joint application.
The ammunition in the sea is an environmental and security problem that has been ignored by the federal government for decades, said Steffi Lemke, the parliamentary manager of the Green Group.
For the recovery, sonar technology and magnetic probes could initially be used to track down the war junk.
Robots may then help.
joe / dpa