World War II Bombs, Torpedoes and Naval Mines: How Marine Life Prosper on Discarded Armaments

In the slightly salty sea off the Germany's coast lies a graveyard of World War II explosives, torpedoes and mines. Discarded from boats at the end of the second world war and forgotten about, numerous explosives have become matted together over the decades. They create a corroding carpet on the low-depth, silty ocean floor of the Lübeck Bay in the western part of the Baltic Sea.

Over the years, the Nazi arsenal was ignored and neglected. A increasing amount of tourists came to the sandy beaches and calm waters for jetskiing, kite surfing and amusement parks. Underwater, the weapons deteriorated.

Some of us expected to see a lifeless zone, with no life because it was all poisoned, says the lead researcher.

When the initial researchers went looking to see what they were doing to the ecosystem, the team thought they would find a barren area, with nothing living there because it was all contaminated, states a scientist.

What they observed surprised them. Vedenin remembers his colleagues exclaiming in amazement when the submersible first relayed pictures. It was a memorable occasion, he notes.

Thousands of sea creatures had settled among the munitions, creating a regenerated ecosystem more populous than the ocean bottom surrounding it.

This underwater metropolis was testament to the persistence of life. Indeed surprising how much marine organisms we find in places that are expected to be toxic and dangerous, he says.

Over 40 sea stars had piled on to one visible piece of explosive material. They were living on steel casings, ignition chambers and transport cases just centimetres from its explosive filling. Marine fish, crustaceans, sea anemones and bivalves were all found on the discarded explosives. It's similar to a marine reef in terms of the quantity of animal life that was inhabiting the area, says Vedenin.

Surprising Population Density

An average of more than 40,000 creatures were dwelling on every square metre of the weapons, experts wrote in their study on the finding. The nearby seabed was much sparser, with only eight thousand organisms on every meter squared.

It is surprising that items that are meant to eliminate all life are drawing so much life, says Vedenin. One can observe how the natural world evolves after a major disaster such as the second world war and how, in certain respects, life finds its way to the most risky areas.

Man-made Structures as Ocean Habitats

Artificial structures such as sunken vessels, offshore windfarms, oil rigs and pipelines can offer alternatives, restoring some of the removed habitat. This investigation demonstrates that munitions could be equally positive – the proliferation of marine organisms on those in the Bay of Lübeck is expected to be found elsewhere.

Between the late 1940s and the post-war period, 1.6m tonnes of weapons were disposed of off the Germany's shoreline. Thousands of people placed them in vessels; some were dropped in designated areas, others just thrown overboard en route. This is the first time experts have documented how marine life has adapted.

Worldwide Examples of Ocean Transformation

• In the United States, decommissioned oil and gas structures have transformed into reef ecosystems
• Sunken ships from the first world war have become homes for marine life along the Potomac River in Maryland
• Military vehicle parts that have become environment to coral off Asan in the Pacific island

These places become even more crucial for organisms as the marine environments are increasingly depleted by fishing, seafloor dredging and anchoring. Shipwrecks and weapons dump sites effectively act as protected areas – they are not national parks, but virtually any kind of anthropogenic disturbance is banned, says Vedenin. Consequently a many of organisms that are usually rare or diminishing, such as the Baltic cod, are thriving.

Future Factors

Anywhere armed conflict has taken place in the last century, adjacent waters are often littered with explosives, says Vedenin. Millions of tons of volatile compounds rest in our oceans.

The positions of these explosives are inadequately recorded, partially because of sovereign limits, restricted defense data and the fact that records are buried in old files. They pose an detonation and security risk, as well as risk from the persistent release of toxic chemicals.

As the German government and other countries embark on removing these relics, scientists hope to safeguard the habitats that have formed in their vicinity. In the Lübeck Bay munitions are currently being removed.

Researchers recommend replace these iron structures originating from munitions with certain less dangerous, various safe objects, like perhaps concrete structures, states Vedenin.

He presently wishes that what occurs in Lübeck creates a example for replacing habitats after weapon clearance in different areas – because also the most harmful explosives can become foundation for new life.