World War II Bombs, Torpedoes and Naval Mines: How Ocean Creatures Prosper on Abandoned Armaments

In the slightly salty sea off the German shoreline lies a collection of Nazi bombs, torpedoes and naval mines. Dumped from barges at the end of the second world war and left behind, numerous explosives have become matted together over the years. They create a rusting carpet on the shallow, silty seafloor of the Lübeck Bay in the western part of the Baltic Sea.

Over the years, the explosive stockpile was ignored and neglected. A increasing amount of tourists came to the coastal areas and tranquil sea for water sports, kiteboarding and amusement parks. Beneath the surface, the munitions deteriorated.

Researchers anticipated to see a lifeless zone, with no organisms because it was all contaminated, states a scientist.

When the first scientists went searching to see what they were doing to the ecosystem, the team expected to see a barren area, with no organisms because it was all contaminated, states a scientist.

What they found surprised them. Vedenin remembers his team members exclaiming in amazement when the underwater vehicle first sent the images back. This was a great moment, he recalls.

Thousands of marine animals had established habitats among the munitions, developing a revitalized marine community more populous than the ocean bottom surrounding it.

This marine city was evidence to the resilience of marine life. It is actually astonishing how much marine organisms we find in areas that are considered hazardous and risky, he explains.

More than 40 starfish had piled on to one exposed fragment of TNT. They were dwelling on metal shells, fuse pockets and transport cases just a short distance from its dangerous content. Fish, crabs, anemones and mussels were all found on the discarded explosives. It resembles a marine reef in terms of the quantity of creatures that was present, notes Vedenin.

Surprising Population Density

An average of more than 40,000 organisms were dwelling on every square metre of the weapons, experts wrote in their study on the observation. The adjacent region was much less diverse, with only 8,000 individuals on every square metre.

It is surprising that items that are intended to eliminate all life are hosting so much marine organisms, says Vedenin. One can observe how the natural world adjusts after a major disaster such as the second world war and how, in certain respects, marine life establishes itself to the most risky locations.

Artificial Features as Ocean Environments

Man-made structures such as sunken vessels, wind turbines, oil rigs and undersea pipes can create alternatives, compensating for some of the lost marine environment. This investigation shows that weapons could be similarly beneficial – the explosion of marine organisms on those in the Lübeck Bay is likely to be repeated elsewhere.

Between the late 1940s and the post-war period, 1.6m tonnes of munitions were dumped off the German coast. Thousands of people transported them in vessels; some were dropped in specific sites, the remainder just thrown overboard while traveling. This is the first time researchers have documented how marine life has reacted.

Global Examples of Ocean Adaptation

• In the US, retired oil and gas structures have become marine habitats
• Shipwrecks from the World War I have become environments for creatures along the Potomac River 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 important for organisms as the marine environments are increasingly stripped by commercial fishing, bottom trawling and anchoring. Sunken ships and weapons dump sites essentially function as refuges – they are not national parks, but nearly any kind of human activity is banned, explains Vedenin. Therefore a many of organisms that are typically uncommon or declining, such as the Baltic cod, are flourishing.

Future Factors

Anywhere armed conflict has happened in the last century, surrounding seas are often littered with munitions, explains Vedenin. Millions of tons of dangerous substances lie in our oceans.

The positions of these explosives are poorly mapped, in part because of international boundaries, restricted defense data and the situation that archives are buried in old files. They create an detonation and security risk, as well as threat from the persistent emission of poisonous compounds.

As Germany and additional nations embark on extracting these relics, experts aim to preserve the ecosystems that have established around them. In the Lübeck Bay explosives are presently being cleared.

We should replace these iron structures originating from weapons with some more secure, some harmless objects, like possibly artificial reefs, suggests Vedenin.

He presently aspires that what occurs in the Bay of Lübeck sets a example for substituting structures after weapon clearance in other locations – because including the most harmful weaponry can become foundation for ocean ecosystems.