Nazi Munitions, Torpedo Heads and Naval Mines: How Marine Life Prosper on Discarded Armaments

In the slightly salty waters off the Germany's coast lies a wasteland of Nazi bombs, torpedoes and mines. Thrown off boats at the end of the second world war and left behind, numerous munitions have fused into clusters over the years. They create a corroding layer on the low-depth, silty seafloor of the Bay of Lübeck in the western tip of the Baltic.

Over the years, the explosive stockpile was overlooked and neglected. A growing number of visitors came to the coastal areas and calm waters for water sports, kiteboarding and entertainment venues. Underwater, the weapons deteriorated.

We initially expected to see a lifeless zone, with nothing living there because it was all contaminated, says Andrey Vedenin.

When the team went investigating to see what they were doing to the marine environment, the team expected to see a desert, with no organisms because it was all poisoned, states Andrey Vedenin.

What they found surprised them. Vedenin recalls his scientists shouting with surprise when the submersible first sent the images back. This was a great moment, he recalls.

Thousands of ocean life had settled on the explosives, forming a regenerated ecosystem denser than the ocean bottom around it.

This underwater metropolis was proof to the resilience of life. Indeed remarkable how much marine organisms we observe in locations that are supposed to be hazardous and harmful, he says.

In excess of 40 starfish had piled on to one accessible fragment of explosive material. They were dwelling on steel casings, fuse pockets and transport cases just centimetres from its explosive filling. Marine fish, crustaceans, sea anemones and mussels were all found on the old munitions. It's similar to a marine reef in terms of the quantity of creatures that was inhabiting the area, states Vedenin.

Unexpected Creature Concentration

An mean of more than 40,000 creatures were dwelling on every meter squared of the explosives, scientists reported in their paper on the observation. The surrounding area was much less diverse, with only 8,000 individuals on every square metre.

It is paradoxical that things that are intended to kill all life are attracting so much marine organisms, explains Vedenin. One can observe how the natural world adjusts after a devastating occurrence such as the World War II and how, in certain respects, marine life establishes itself to the most risky areas.

Man-made Structures as Marine Habitats

Man-made structures such as shipwrecks, wind turbines, drilling platforms and undersea pipes can provide alternatives, replacing some of the removed marine environment. This research shows that explosives could be comparably beneficial – the proliferation of life on those in the Bay of Lübeck is likely to be repeated elsewhere.

Between the late 1940s and the post-war period, 1.6 million tonnes of munitions were discarded off the German coast. Countless of workers loaded them in vessels; some were dropped in designated locations, the remainder just dumped en route. This is the first time researchers have documented how marine life has responded.

Worldwide Instances of Ocean Adaptation

• In the United States, decommissioned oil and gas structures have turned into marine habitats
• Sunken ships from the first world war have become homes for wildlife along the Potomac in Maryland
• Military vehicle parts that have become environment to reef-building organisms off Asan beach in the Pacific island

These locations become even more important for marine life as the marine environments are increasingly depleted by commercial fishing, seafloor dredging and anchoring. Sunken ships and weapons dump sites effectively serve as refuges – they are not official reserves, but virtually any kind of human activity is prohibited, explains Vedenin. Therefore a lot of species that are typically scarce or diminishing, such as the cod fish, are flourishing.

Coming Factors

Wherever warfare has happened in the past 100 years, surrounding seas are usually strewn with explosives, explains Vedenin. Many millions of tonnes of dangerous substances lie in our seas.

The locations of these explosives are insufficiently recorded, partially because of sovereign limits, restricted military information and the situation that documents are stored in historic archives. They pose an detonation and safety hazard, as well as risk from the persistent release of hazardous substances.

As Germany and additional nations start clearing these relics, researchers plan to protect the ecosystems that have developed nearby. In the Bay of Lübeck explosives are presently being extracted.

It would be wise to replace these metal carcasses originating from munitions with some safer, some non-dangerous materials, like possibly concrete structures, states Vedenin.

He presently hopes that what happens in Lübeck establishes a example for replacing material after munitions removal in different areas – because even the most harmful armaments can become framework for ocean ecosystems.