World War II Bombs, Torpedo Heads and Mines: The Way Marine Life Flourishes on Discarded Weapons

In the slightly salty waters off the German coast sits a wasteland of Nazi bombs, torpedo heads and naval mines. Thrown off barges at the end of the second world war and neglected, numerous explosives have fused into clusters over the years. They form a rusting layer on the shallow, muddy ocean floor of the Bay of Lübeck in the western part of the Baltic.

Over the years, the explosive stockpile was ignored and forgotten about. A growing number of tourists traveled to the coastal areas and tranquil sea for jetskiing, kiteboarding and entertainment venues. Below the waves, the weapons deteriorated.

Some of us thought to see a lifeless zone, with no organisms because it was all toxic, explains a scientist.

When the team went investigating to see what they were affecting to the ecosystem, the team anticipated finding a barren area, with nothing living there because it was all poisoned, says Andrey Vedenin.

What they found surprised them. Vedenin remembers his team members shouting with surprise when the ROV first sent the images back. That moment was a remarkable experience, he says.

Countless of marine animals had established habitats among the explosives, developing a revitalized marine community richer than the ocean bottom around it.

This marine city was proof to the tenacity of life. Truly remarkable how much life we discover in locations that are supposed to be hazardous and dangerous, he explains.

In excess of 40 sea stars had piled on to one visible fragment of explosive material. They were residing on steel casings, detonator compartments and storage boxes just a short distance from its dangerous content. Marine fish, crustaceans, anemones and mussels were all discovered on the discarded explosives. You could compare it with a reef ecosystem in terms of the quantity of animal life that was present, says Vedenin.

Remarkable Creature Concentration

An mean of more than 40,000 organisms were living on every square metre of the munitions, scientists documented in their paper on the observation. The nearby seabed was much sparser, with only 8,000 individuals on every meter squared.

It is paradoxical that things that are meant to eliminate everything are drawing so much marine organisms, states Vedenin. You can see how the natural world evolves after a devastating occurrence such as the World War II and how, in some way, life finds its way to the most risky places.

Man-made Structures as Marine Habitats

Man-made structures such as sunken vessels, offshore windfarms, drilling platforms and undersea pipes can offer replacements, compensating for some of the lost marine environment. This study shows that munitions could be comparably beneficial – the explosion of marine organisms on those in the Bay of Lübeck is probable to be duplicated elsewhere.

Between the late 1940s and the post-war period, 1.6m tonnes of weapons were dumped off the Germany's coast. Thousands of individuals loaded them in barges; some were dropped in specific sites, others just discarded at sea during transport. This is the initial instance scientists have documented how marine life has responded.

Global Examples of Marine Transformation

• In the United States, decommissioned oil and gas structures have turned into coral reefs
• Shipwrecks from the World War I have become habitats for creatures along the Potomac in the state of Maryland
• Tank tracks that have become home to reef-building organisms off Asan in the Pacific island

These places become even more valuable for wildlife as the seas are increasingly denuded by commercial fishing, bottom trawling and anchoring. Shipwrecks and munitions areas effectively function as refuges – they are not national parks, but almost any kind of anthropogenic disturbance is banned, says Vedenin. Therefore a lot of organisms that are otherwise scarce or declining, such as the cod fish, are flourishing.

Future Considerations

Anywhere warfare has occurred in the last century, surrounding seas are typically containing explosives, explains Vedenin. Many millions of tons of dangerous substances rest in our marine environments.

The sites of these explosives are poorly mapped, partly because of international boundaries, secret defense data and the situation that archives are stored in historic archives. They pose an explosion and security risk, as well as risk from the ongoing release of hazardous substances.

As the German government and additional nations start removing these artifacts, experts plan to safeguard the ecosystems that have formed around them. In the Bay of Lübeck munitions are presently being cleared.

It would be wise to substitute these iron structures originating from weapons with certain safer, some harmless materials, like possibly man-made habitats, suggests Vedenin.

He currently aspires that what happens in the Bay of Lübeck establishes a precedent for replacing structures after munitions removal in other locations – because including the most destructive weaponry can become framework for marine organisms.