World War II Explosives, Torpedo Heads and Mines: The Way Ocean Creatures Prosper on Discarded Weapons

In the brackish sea off the German shoreline lies a collection of World War II explosives, torpedo heads and naval mines. Thrown off vessels at the end of the second world war and forgotten about, countless munitions have become matted together over the years. They create a corroding layer on the low-depth, silty seafloor of the Lübeck Bay in the western tip of the Baltic.

Over the years, the Nazi arsenal was ignored and neglected. A growing number of visitors traveled to the sandy beaches and calm waters for water sports, kite surfing and entertainment venues. Below the waves, the weapons eroded.

We initially thought to see a desert, with nothing living there because it was all toxic, states Andrey Vedenin.

When the team went looking to see what they were doing to the marine environment, the team thought they would find a barren area, with nothing living there because it was all poisoned, says the lead researcher.

What they found amazed them. Vedenin recalls his scientists reacting with shock when the ROV first relayed pictures. It was a memorable occasion, he notes.

Countless of sea creatures had established habitats amid the explosives, forming a regenerated habitat richer than the seabed surrounding it.

This marine city was testament to the tenacity of marine life. Indeed surprising how much marine organisms we find in places that are supposed to be toxic and dangerous, he says.

More than 40 starfish had piled on to one visible fragment of explosive material. They were living on metal shells, ignition chambers and storage boxes just centimetres from its explosive filling. Marine fish, crustaceans, anemones and mussels were all found on the old munitions. It's similar to a reef ecosystem in terms of the amount of fauna that was present, states Vedenin.

Surprising Creature Concentration

An mean of more than 40,000 organisms were living on every square metre of the explosives, experts wrote in their research on the observation. The adjacent region was much poorer in life, with only eight thousand individuals on every square metre.

It is ironic that objects that are meant to eliminate all life are drawing so much marine organisms, states Vedenin. One can observe how nature evolves after a catastrophic event such as the second world war and how, in some way, marine life finds its way to the most dangerous areas.

Man-made Structures as Ocean Environments

Artificial structures such as shipwrecks, wind turbines, oil rigs and pipelines can create substitutes, restoring some of the removed marine environment. 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 found in other locations.

Between 1946 and 1948, 1.6m tons of munitions were disposed of off the German shoreline. Thousands of individuals loaded them in vessels; some were placed in specific areas, others just discarded at sea while traveling. This is the initial instance scientists have documented how marine life has reacted.

Global Instances of Marine Adaptation

• In the US, retired energy installations have become reef ecosystems
• Sunken ships from the first world war have become habitats for creatures along the Potomac in Maryland
• Military vehicle parts that have become home to coral off Asan beach in Guam

These locations become even more important for wildlife as the marine environments are increasingly denuded by commercial fishing, bottom trawling and anchoring. Sunken ships and explosive disposal locations effectively function as protected areas – they are not national parks, but almost any kind of anthropogenic disturbance is prohibited, explains Vedenin. Therefore a many of organisms that are typically uncommon or decreasing, such as the Baltic cod, are flourishing.

Coming Issues

Anywhere military conflict has occurred in the last century, adjacent waters are typically littered with munitions, explains Vedenin. Many millions of tons of dangerous substances lie in our seas.

The sites of these munitions are insufficiently mapped, partly because of international boundaries, classified military information and the fact that records are buried in historical records. They present an detonation and security hazard, as well as risk from the persistent emission of poisonous compounds.

As the German government and other countries start extracting these relics, scientists plan to safeguard the marine communities that have established nearby. In the Bay of Lübeck munitions are presently being cleared.

Researchers recommend substitute these iron structures originating from weapons with certain more secure, some non-dangerous objects, like maybe man-made habitats, says Vedenin.

He presently wishes that what transpires in Lübeck creates a example for replacing habitats after explosive extraction elsewhere – because including the most destructive weaponry can become scaffolding for marine organisms.