World War II Munitions, Torpedo Heads and Naval Mines: How Marine Life Thrives on Dumped Armaments

In the brackish waters off the German shoreline lies a graveyard of Nazi bombs, torpedo heads and mines. Discarded from barges at the end of the second world war and neglected, numerous weapons have fused into clusters over the decades. They form a decaying layer on the shallow, muddy seafloor of the Lübeck Bay in the western part of the Baltic Sea.

Over the years, the Nazi arsenal was ignored and neglected. A growing number of tourists flocked to the coastal areas and calm waters for water sports, kiteboarding and amusement parks. Beneath the surface, the munitions eroded.

Researchers expected to see a lifeless zone, with no life because it was all poisoned, states a scientist.

When the initial researchers went looking to see what they were doing to the ecosystem, some of us thought they would find a lifeless zone, with no organisms because it was all poisoned, says the lead researcher.

What they found astonished them. Vedenin remembers his scientists reacting with shock when the underwater vehicle first transmitted footage. That moment was a great moment, he says.

Numerous of sea creatures had settled on the munitions, developing a renewed marine community denser than the ocean bottom around it.

This underwater metropolis was proof to the tenacity of life. Indeed surprising how much life we find in areas that are expected to be hazardous and harmful, he explains.

More than 40 sea stars had gathered on to one visible chunk of TNT. They were living on steel casings, detonator compartments and carrying containers just centimetres from its dangerous content. Marine fish, crabs, anemones and mussels were all observed on the discarded explosives. It's similar to a marine reef in terms of the quantity of fauna that was inhabiting the area, notes Vedenin.

Unexpected Creature Concentration

An average of more than forty thousand creatures were living on every square metre of the explosives, researchers wrote in their paper on the discovery. The surrounding area was much sparser, with only eight thousand organisms on every square metre.

It is surprising that objects that are meant to kill all life are hosting so much marine organisms, states Vedenin. It's evident how nature evolves after a major disaster such as the World War II and how, in certain respects, life returns to the most dangerous places.

Man-made Features as Marine Environments

Artificial features such as sunken vessels, offshore windfarms, drilling platforms and undersea pipes can provide substitutes, compensating for some of the removed habitat. This study shows that munitions could be comparably beneficial – the explosion of life on those in the Bay of Lübeck is likely to be duplicated in other locations.

Between the late 1940s and the post-war period, 1.6 million tons of arms were dumped off the Germany's shoreline. Thousands of people placed them in boats; a portion were dropped in specific areas, the remainder just thrown overboard during transport. This is the first time scientists have documented how ocean organisms has reacted.

Worldwide Examples of Ocean Adaptation

• In the United States, retired oil and gas structures have turned into reef ecosystems
• Sunken ships from the first world war have become environments for marine life along the Potomac River in Maryland
• Tank tracks that have become environment to coral off Asan beach in Guam

These areas become even more valuable for wildlife as the oceans are increasingly depleted by fishing, seafloor dredging and anchoring. Shipwrecks and explosive disposal locations essentially function as protected areas – they are not official reserves, but nearly any kind of anthropogenic disturbance is restricted, states Vedenin. As a result a lot of species that are usually scarce or declining, such as the Baltic cod, are prospering.

Coming Issues

Anywhere armed conflict has occurred in the recent history, surrounding seas are often littered with weapons, says Vedenin. Millions of tonnes of explosive material rest in our oceans.

The locations of these munitions are insufficiently recorded, partly because of national borders, classified armed forces records and the reality that records are stored in historical records. They create an detonation and security risk, as well as danger from the continuous release of toxic chemicals.

As the German government and other countries start removing these remains, researchers hope to protect the ecosystems that have established around them. In the Lübeck Bay weapons are presently being cleared.

We should substitute these iron structures originating from munitions with some safer, various harmless materials, like possibly man-made habitats, says Vedenin.

He currently hopes that what happens in the Bay of Lübeck sets a model for substituting material after weapon clearance elsewhere – because also the most destructive explosives can become foundation for marine organisms.