Nazi Explosives, Torpedo Heads and Naval Mines: How Ocean Creatures Flourishes on Abandoned Armaments

In the slightly salty sea off the German shoreline rests a collection of Nazi bombs, torpedo heads and mines. Dumped from barges at the end of the World War II and neglected, thousands explosives have fused into clusters over the years. They create a rusting layer on the shallow, muddy ocean floor of the Bay of Lübeck in the western part of the Baltic.

Over the decades, the explosive stockpile was overlooked and neglected. A increasing amount of tourists came to the sandy beaches and calm waters for jetskiing, kiteboarding and entertainment venues. Below the waves, the munitions deteriorated.

Researchers thought to see a barren area, with no organisms because it was all toxic, says the lead researcher.

When the initial researchers went investigating to see what they were doing to the ecosystem, the team thought they would find a lifeless zone, with no organisms because it was all toxic, states a scientist.

What they found amazed them. Vedenin remembers his colleagues reacting with shock when the submersible first relayed pictures. It was a great moment, he says.

Countless of marine animals had made their homes amid the explosives, developing a revitalized ecosystem denser than the sea floor surrounding it.

This underwater metropolis was testament to the resilience of life. It is actually surprising how much marine organisms we discover in locations that are considered toxic and dangerous, he states.

More than 40 starfish had clustered on to one visible chunk of TNT. They were living on metal shells, fuse pockets and carrying containers just centimetres from its explosive filling. Fish, crustaceans, anemones and mussels were all observed on the historic weapons. You could compare it with a coral reef in terms of the amount of fauna that was inhabiting the area, notes Vedenin.

Remarkable Creature Concentration

An mean of more than 40,000 organisms were residing on every meter squared of the munitions, researchers wrote in their paper on the finding. The surrounding area was much sparser, with only 8,000 creatures on every meter squared.

It is surprising that things that are meant to eliminate all life are attracting so much marine organisms, explains Vedenin. One can observe how the natural world adapts after a major disaster such as the second world war and how, in certain respects, life returns to the most hazardous places.

Artificial Features as Ocean Environments

Artificial structures such as sunken vessels, wind turbines, drilling platforms and undersea pipes can provide replacements, replacing some of the lost habitat. This study reveals that munitions could be similarly advantageous – the explosion of marine organisms on those in the Lübeck Bay is probable to be repeated in other locations.

Between 1946 and the post-war period, 1.6 million tonnes of munitions were dumped off the Germany's shoreline. Thousands of people placed them in vessels; some were dropped in allocated sites, the remainder just discarded at sea while traveling. This is the first time experts have studied how ocean organisms has reacted.

Worldwide Instances of Marine Transformation

• In the United States, decommissioned energy installations have become coral reefs
• Shipwrecks from the first world war have become homes for marine life along the Potomac River in the state of Maryland
• Military vehicle parts that have become home to reef-building organisms off Asan in Guam

These places become even more valuable for organisms as the oceans are increasingly stripped by fishing, seafloor dredging and anchoring. Shipwrecks and weapons dump sites effectively act as refuges – they are not official reserves, but almost any kind of human activity is restricted, states Vedenin. As a result a lot of marine species that are typically rare or decreasing, such as the cod fish, are thriving.

Coming Factors

Wherever warfare has happened in the past 100 years, surrounding seas are often containing munitions, explains Vedenin. Millions of tons of explosive material remain in our seas.

The positions of these munitions are insufficiently mapped, in part because of international boundaries, restricted defense data and the situation that records are hidden in historic archives. They pose an explosion and security risk, as well as risk from the continuous leakage of poisonous compounds.

As the German government and other countries start extracting these remains, scientists plan to safeguard the marine communities that have established in their vicinity. In the Bay of Lübeck weapons are already being cleared.

It would be wise to substitute these iron structures left from weapons with some less dangerous, various safe structures, like possibly man-made habitats, says Vedenin.

He presently hopes that what occurs in Lübeck sets a precedent for replacing structures after explosive extraction elsewhere – because also the most harmful armaments can become scaffolding for marine organisms.