World War II Bombs, Torpedo Heads and Naval Mines: How Marine Life Flourishes on Discarded Armaments

In the brackish sea off the Germany's shoreline lies a wasteland of World War II explosives, torpedo heads and mines. Thrown off barges at the conclusion of the second world war and neglected, countless weapons have accumulated over the decades. They create a rusting blanket on the low-depth, silty ocean floor of the Bay of Lübeck in the western part of the Baltic.

Over the decades, the Nazi arsenal was overlooked and forgotten about. A increasing amount of visitors came to the coastal areas and calm waters for water sports, kiteboarding and amusement parks. Beneath the surface, the munitions deteriorated.

We initially thought to see a lifeless zone, with no organisms because it was all toxic, explains the lead researcher.

When the team went searching to see what they were doing to the marine environment, the team thought they would find a lifeless zone, with nothing living there because it was all poisoned, states Andrey Vedenin.

What they found astonished them. Vedenin remembers his scientists reacting with shock when the submersible first sent the images back. It was a remarkable experience, he notes.

Countless of sea creatures had established habitats among the munitions, developing a revitalized marine community more populous than the ocean bottom nearby.

This ocean community was evidence to the resilience of life. It is actually surprising how much life we observe in locations that are considered toxic and dangerous, he explains.

Over 40 starfish had clustered on to one visible chunk of TNT. They were living on iron containers, fuse pockets and storage boxes just centimetres from its explosive filling. Marine fish, crabs, anemones and bivalves were all found on the historic weapons. You could compare it with a marine reef in terms of the amount of creatures that was inhabiting the area, notes Vedenin.

Unexpected Creature Concentration

An average of more than forty thousand organisms were dwelling on every meter squared of the explosives, scientists reported in their paper on the observation. The nearby seabed was much less diverse, with only 8,000 individuals on every meter squared.

It is ironic that objects that are designed to eliminate all life are attracting so much life, says Vedenin. You can see how nature adjusts after a devastating occurrence such as the second world war and how, in some way, marine life finds its way to the most dangerous areas.

Artificial Structures as Marine Habitats

Man-made features such as shipwrecks, offshore windfarms, oil rigs and pipelines can create substitutes, replacing some of the lost habitat. This study reveals that munitions could be equally positive – the explosion of life on those in the Lübeck Bay is probable to be repeated in other locations.

Between the late 1940s and 1948, 1.6 million tonnes of munitions were discarded off the Germany's shoreline. Countless of individuals placed them in barges; a portion were deposited in designated sites, the remainder just discarded at sea while traveling. This is the first time researchers have recorded how ocean organisms has responded.

Global Examples of Ocean Adaptation

• In the US, decommissioned drilling platforms have transformed into coral reefs
• Sunken ships from the World War I have become homes for marine life along the Potomac River in Maryland
• Military vehicle parts that have become environment to reef-building organisms off Asan beach in the Pacific island

These places become even more important for marine life as the seas are increasingly stripped by commercial fishing, bottom trawling and boat mooring. Shipwrecks and munitions areas practically act as refuges – they are not official reserves, but almost any kind of human activity is banned, explains Vedenin. As a result a numerous of species that are usually scarce or decreasing, such as the cod fish, are thriving.

Future Factors

Anywhere military conflict has happened in the last century, surrounding seas are usually containing explosives, states Vedenin. Millions of tonnes of volatile compounds remain in our oceans.

The locations of these explosives are insufficiently mapped, partly because of international boundaries, secret defense data and the situation that archives are hidden in historical records. They present an explosion and safety danger, as well as risk from the ongoing release of hazardous substances.

As the German government and other countries start removing these relics, scientists hope to safeguard the marine communities that have formed nearby. In the Bay of Lübeck munitions are already being cleared.

It would be wise to substitute these metal carcasses remaining from weapons with certain less dangerous, some safe structures, like perhaps man-made habitats, states Vedenin.

He now wishes that what occurs in the Bay of Lübeck establishes a model for replacing structures after weapon clearance in other locations – because also the most harmful armaments can become framework for ocean ecosystems.