World War II Explosives, Torpedoes and Naval Mines: How Ocean Creatures Flourishes on Abandoned Weapons

In the brackish sea off the German coast lies a wasteland of Nazi bombs, torpedo heads and naval mines. Dumped from boats at the end of the second world war and neglected, numerous weapons have become matted together over the decades. They create a decaying layer on the shallow, muddy ocean floor of the Lübeck Bay in the western tip of the Baltic.

Over the years, the Nazi arsenal was overlooked and neglected. A growing number of visitors came to the coastal areas and calm waters for jetskiing, kiteboarding and amusement parks. Beneath the surface, the weapons eroded.

Researchers thought to see a lifeless zone, with no organisms because it was all poisoned, states the lead researcher.

When the first scientists went looking to see what they were affecting to the ecosystem, researchers anticipated finding a lifeless zone, with nothing living there because it was all poisoned, says a scientist.

What they observed astonished them. Vedenin recounts his colleagues reacting with shock when the underwater vehicle first transmitted footage. This was a great moment, he says.

Thousands of marine animals had settled on the weapons, creating a revitalized marine community denser than the sea floor around it.

This underwater metropolis was testament to the persistence of life. Indeed astonishing how much life we observe in locations that are expected to be hazardous and harmful, he says.

Over 40 starfish had piled on to one visible piece of TNT. They were living on steel casings, detonator compartments and transport cases just centimetres from its explosive filling. Marine fish, crabs, anemones and bivalves were all found on the discarded explosives. You could compare it with a marine reef in terms of the abundance of fauna that was inhabiting the area, notes Vedenin.

Surprising Population Density

An mean of more than 40,000 organisms were living on every meter squared of the explosives, experts wrote in their research on the finding. The adjacent region was much sparser, with only eight thousand individuals on every meter squared.

It is paradoxical that things that are meant to kill everything are drawing so much marine organisms, says Vedenin. One can observe how the natural world adapts after a major disaster such as the World War II and how, in some way, life establishes itself to the most risky places.

Artificial Features as Marine Habitats

Artificial structures such as sunken vessels, offshore windfarms, oil rigs and pipelines can create substitutes, replacing some of the destroyed habitat. This study demonstrates that munitions could be similarly advantageous – the bloom 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 tonnes of munitions were dumped off the German coast. Thousands of individuals loaded them in barges; some were dropped in specific areas, others just thrown overboard during transport. This is the initial instance scientists have studied how ocean organisms has adapted.

Worldwide Instances of Marine Transformation

• In the US, decommissioned drilling platforms have become marine habitats
• Sunken ships from the first world war have become environments for wildlife along the Potomac in Maryland
• Tank tracks that have become habitat to coral off Asan in the Pacific island

These locations become even more important for organisms as the oceans are increasingly denuded by commercial fishing, seafloor dredging and anchoring. Sunken ships and munitions areas essentially serve as protected areas – they are not official reserves, but virtually any kind of human activity is banned, explains Vedenin. Consequently a many of species that are typically rare or decreasing, such as the cod fish, are flourishing.

Coming Considerations

Anywhere military conflict has happened in the recent history, adjacent waters are often containing explosives, says Vedenin. Many millions of tonnes of explosive material rest in our marine environments.

The positions of these explosives are inadequately documented, partially because of national borders, secret defense data and the fact that documents are stored in historical records. They present an explosion and safety danger, as well as danger from the continuous leakage of poisonous compounds.

As Germany and other countries embark on removing these artifacts, researchers plan to safeguard the habitats that have formed in their vicinity. In the Lübeck Bay munitions are presently being extracted.

It would be wise to replace these metal carcasses originating from munitions with some less dangerous, some harmless materials, like possibly artificial reefs, suggests Vedenin.

He presently aspires that what happens in the Bay of Lübeck creates a example for substituting material after explosive extraction in different areas – because also the most harmful explosives can become scaffolding for marine organisms.