Nazi Bombs, Torpedo Heads and Naval Mines: How Ocean Creatures Thrives on Abandoned Armaments

In the slightly salty sea off the Germany's shoreline lies a graveyard of Nazi bombs, torpedo heads and mines. Thrown off boats at the end of the second world war and left behind, numerous weapons have fused into clusters over the years. They create a corroding blanket on the shallow, silty ocean floor of the Bay of Lübeck in the western tip of the Baltic.

Over the years, the Nazi arsenal was overlooked and forgotten about. A growing number of tourists flocked to the sandy beaches and calm waters for water sports, kiteboarding and amusement parks. Underwater, the weapons decayed.

We initially thought to see a desert, with no organisms because it was all contaminated, says the lead researcher.

When the team went searching to see what they were doing to the ecosystem, the team thought they would find a desert, with no life because it was all contaminated, explains Andrey Vedenin.

What they observed surprised them. Vedenin recalls his colleagues shouting with surprise when the underwater vehicle first transmitted footage. This was a remarkable experience, he recalls.

Thousands of marine animals had established habitats amid the weapons, forming a revitalized ecosystem richer than the seabed around it.

This marine city was evidence to the tenacity of life. It is actually surprising how much life we observe in places that are expected to be dangerous and harmful, he states.

More than 40 sea stars had gathered on to one visible fragment of explosive material. They were dwelling on steel casings, fuse pockets and storage boxes just centimetres from its explosive filling. Fish, crabs, sea anemones and bivalves were all observed on the historic weapons. It's similar to a reef ecosystem in terms of the quantity of animal life that was inhabiting the area, states Vedenin.

Surprising Creature Concentration

An average of more than 40,000 organisms were residing on every square metre of the explosives, researchers reported in their research on the observation. The surrounding area was much sparser, with only eight thousand creatures on every meter squared.

It is ironic that items that are meant to kill all life are hosting so much marine organisms, says Vedenin. It's evident how the natural world adjusts after a major disaster such as the World War II and how, in some way, life returns to the most dangerous locations.

Artificial Structures as Marine Environments

Artificial features such as sunken vessels, offshore windfarms, drilling platforms and undersea pipes can create substitutes, restoring some of the removed marine environment. This investigation reveals that munitions could be equally positive – the proliferation of marine organisms on those in the Bay of Lübeck is expected to be repeated in different areas.

Between the late 1940s and 1948, 1.6 million tons of munitions were dumped off the Germany's shoreline. Countless of workers placed them in barges; some were dropped in allocated sites, the remainder just discarded at sea during transport. This is the first time researchers have studied how ocean organisms has reacted.

Global Instances of Ocean Adaptation

• In the United States, retired oil and gas structures have turned into reef ecosystems
• Sunken ships from the World War I have become habitats for wildlife along the Potomac River in Maryland
• Tank tracks that have become habitat to reef-building organisms off Asan in the Pacific island

These locations become even more crucial for wildlife as the marine environments are increasingly depleted by commercial fishing, seafloor dredging and anchoring. Shipwrecks and munitions areas practically serve as sanctuaries – they are not national parks, but virtually any kind of human activity is prohibited, explains Vedenin. Therefore a lot of organisms that are usually rare or decreasing, such as the cod fish, are flourishing.

Future Considerations

Anywhere military conflict has occurred in the past 100 years, surrounding seas are usually containing munitions, states Vedenin. Many millions of tonnes of volatile compounds lie in our marine environments.

The sites of these weapons are inadequately documented, in part because of sovereign limits, restricted military information and the reality that documents are buried in historical records. They present an detonation and security hazard, as well as threat from the continuous emission of poisonous compounds.

As the German government and other countries begin extracting these remains, scientists aim to safeguard the marine communities that have established nearby. In the Bay of Lübeck munitions are presently being removed.

It would be wise to replace these iron structures remaining from weapons with certain more secure, various safe objects, like maybe concrete structures, says Vedenin.

He now hopes that what occurs in Lübeck creates a precedent for replacing habitats after munitions removal in other locations – because also the most damaging weaponry can become foundation for marine organisms.