World War II Explosives, Torpedo Heads and Mines: The Way Ocean Creatures Thrives on Dumped Armaments

In the slightly salty sea off the Germany's coast rests a graveyard of Nazi bombs, torpedoes and naval mines. Discarded from barges at the end of the second world war and forgotten about, numerous weapons have accumulated over the years. They form a decaying carpet on the low-depth, muddy seafloor of the Lübeck Bay in the western part of the Baltic Sea.

Over the years, the wartime weapons was ignored and forgotten about. A increasing amount of tourists traveled to the coastal areas and calm waters for water sports, kiteboarding and entertainment venues. Beneath the surface, the weapons eroded.

Some of us expected to see a lifeless zone, with no organisms because it was all contaminated, explains the lead researcher.

When the first scientists went investigating to see what they were doing to the ecosystem, some of us expected to see a barren area, with no life because it was all poisoned, explains the lead researcher.

What they discovered surprised them. Vedenin recalls his team members exclaiming in amazement when the ROV first sent the images back. This was a great moment, he notes.

Numerous of marine animals had established habitats on the weapons, creating a regenerated ecosystem richer than the seabed nearby.

This ocean community was evidence to the tenacity of life. Indeed astonishing how much marine organisms we observe in locations that are expected to be hazardous and risky, he explains.

More than 40 starfish had piled on to one visible chunk of TNT. They were residing on iron containers, fuse pockets and carrying containers just a short distance from its explosive filling. Fish, crustaceans, anemones and bivalves were all discovered on the discarded explosives. It's similar to a reef ecosystem in terms of the quantity of fauna that was present, says Vedenin.

Surprising Population Density

An mean of more than forty thousand animals were living on every square metre of the munitions, researchers documented in their research on the finding. The nearby seabed was much poorer in life, with only eight thousand organisms on every square metre.

It is ironic that items that are intended to eliminate all life are hosting so much marine organisms, says Vedenin. It's evident how the natural world adapts after a catastrophic event such as the second world war and how, in some way, marine life finds its way to the most hazardous places.

Artificial Features as Marine Habitats

Artificial structures such as sunken vessels, offshore windfarms, oil rigs and pipelines can create substitutes, compensating for some of the destroyed marine environment. This investigation shows that munitions could be equally positive – the proliferation of marine organisms on those in the Bay of Lübeck is expected to be duplicated in other locations.

Between 1946 and the post-war period, 1.6m tonnes of weapons were discarded off the German coast. Thousands of workers loaded them in barges; a portion were deposited in designated locations, the remainder just dumped en route. This is the first time scientists have recorded how marine life has responded.

Global Examples of Marine Adaptation

• In the United States, retired energy installations 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 home to reef-building organisms off Asan in the Pacific island

These locations become even more important for wildlife as the marine environments are increasingly denuded by fishing, seafloor dredging and boat mooring. Shipwrecks and munitions areas effectively act as sanctuaries – they are not national parks, but almost any kind of anthropogenic disturbance is banned, explains Vedenin. As a result a many of organisms that are usually uncommon or diminishing, such as the Baltic cod, are prospering.

Coming Considerations

Wherever warfare has occurred in the recent history, nearby oceans are often littered with explosives, explains Vedenin. Many millions of tons of volatile compounds lie in our seas.

The locations of these weapons are poorly documented, partly because of sovereign limits, secret military information and the situation that records are buried in old files. They create an explosion and safety hazard, as well as risk from the continuous leakage of poisonous compounds.

As Germany and other countries embark on clearing these artifacts, researchers hope to preserve the marine communities that have established around them. In the Lübeck Bay weapons are already being cleared.

It would be wise to substitute these iron structures remaining from weapons with some more secure, some harmless structures, like perhaps artificial reefs, suggests Vedenin.

He now aspires that what occurs in the Bay of Lübeck establishes a precedent for replacing material after weapon clearance elsewhere – because also the most harmful armaments can become scaffolding for marine organisms.