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

In the brackish waters off the Germany's coast lies a graveyard of Nazi bombs, torpedo heads and naval mines. Discarded from barges at the conclusion of the second world war and forgotten about, countless explosives have accumulated over the decades. They comprise a decaying layer on the shallow, muddy seafloor of the Lübeck Bay in the western tip of the Baltic.

Over the years, the explosive stockpile was overlooked and neglected. A growing number of tourists came to the sandy beaches and calm waters for jetskiing, kite surfing and amusement parks. Beneath the surface, the munitions decayed.

Researchers expected to see a barren area, with nothing living there because it was all poisoned, explains a scientist.

When the initial researchers went looking to see what they were doing to the ecosystem, researchers expected to see a lifeless zone, with no organisms because it was all poisoned, says a scientist.

What they discovered astonished them. Vedenin remembers his scientists exclaiming in amazement when the ROV first sent the images back. It was a memorable occasion, he says.

Numerous of sea creatures had settled on the munitions, creating a regenerated marine community richer than the sea floor surrounding it.

This underwater metropolis was testament to the tenacity of life. It is actually remarkable how much marine organisms we find in places that are considered toxic and harmful, he states.

More than 40 starfish had gathered on to one accessible piece of TNT. They were dwelling on metal shells, ignition chambers and transport cases just a short distance from its dangerous content. Marine fish, crabs, anemones and mussels were all discovered on the historic weapons. You could compare it with a coral reef in terms of the amount of creatures that was inhabiting the area, notes Vedenin.

Remarkable Population Density

An average of more than forty thousand animals were dwelling on every meter squared of the munitions, researchers wrote in their study on the discovery. The surrounding area was much sparser, with only eight thousand organisms on every square metre.

It is surprising that items that are designed to eliminate everything are attracting so much marine organisms, says Vedenin. One can observe how nature adapts after a devastating occurrence such as the second world war and how, in some way, life finds its way to the most hazardous places.

Artificial Features as Ocean Environments

Artificial features such as shipwrecks, offshore windfarms, drilling platforms and pipelines can provide substitutes, compensating for some of the lost marine environment. This study reveals that weapons could be similarly positive – the explosion of life on those in the Lübeck Bay is expected to be repeated in other locations.

Between 1946 and the post-war period, 1.6 million tonnes of munitions were disposed of off the German shoreline. Thousands of people placed them in vessels; a portion were dropped in specific sites, others just discarded at sea during transport. This is the initial instance scientists have recorded how marine life has responded.

Worldwide Examples of Ocean Transformation

• In the US, retired energy installations have transformed into reef ecosystems
• Shipwrecks from the World War I have become homes for wildlife along the Potomac in Maryland
• Military vehicle parts that have become environment to reef-building organisms off Asan in Guam

These areas become even more valuable for marine life as the oceans are increasingly depleted by fishing, seafloor dredging and boat mooring. Shipwrecks and weapons dump sites practically function as refuges – they are not national parks, but virtually any kind of anthropogenic disturbance is banned, says Vedenin. Therefore a lot of marine species that are otherwise scarce or diminishing, such as the Baltic cod, are thriving.

Future Considerations

Wherever warfare has occurred in the recent history, adjacent waters are often containing munitions, explains Vedenin. Millions of tons of explosive material rest in our marine environments.

The sites of these weapons are inadequately recorded, in part because of international boundaries, secret armed forces records and the reality that documents are stored in historical records. They pose an detonation and security hazard, as well as danger from the continuous release of poisonous compounds.

As the German government and other countries embark on extracting these artifacts, researchers aim to protect the habitats that have developed around them. In the Bay of Lübeck explosives are already being extracted.

We should substitute these steel remains remaining from munitions with some safer, some safe materials, like perhaps concrete structures, says Vedenin.

He presently hopes that what occurs in the Bay of Lübeck creates a model for substituting material after munitions removal elsewhere – because also the most harmful explosives can become framework for ocean ecosystems.