Nazi Munitions, Torpedo Heads and Mines: The Way Ocean Creatures Prosper on Abandoned Weapons

In the slightly salty sea off the Germany's shoreline lies a collection of Nazi bombs, torpedo heads and mines. Thrown off barges at the conclusion of the second world war and neglected, countless weapons have fused into clusters over the decades. They create a corroding blanket on the shallow, silty seafloor of the Lübeck Bay in the western tip of the Baltic Sea.

Over the years, the wartime weapons was overlooked and forgotten about. A growing number of tourists came to the coastal areas and tranquil sea for water sports, kiteboarding and amusement parks. Underwater, the munitions eroded.

Researchers anticipated to see a barren area, with no organisms because it was all contaminated, states Andrey Vedenin.

When the first scientists went looking to see what they were affecting to the ecosystem, some of us anticipated finding a desert, with no life because it was all toxic, explains a scientist.

What they observed astonished them. Vedenin remembers his colleagues shouting with surprise when the ROV first sent the images back. That moment was a remarkable experience, he recalls.

Thousands of ocean life had established habitats among the munitions, developing a regenerated ecosystem denser than the seabed nearby.

This underwater metropolis was proof to the persistence of marine life. Indeed remarkable how much marine organisms we find in areas that are considered dangerous and harmful, he states.

In excess of 40 sea stars had piled on to one exposed chunk of explosive material. They were dwelling on iron containers, fuse pockets and transport cases just a short distance from its dangerous content. Fish, crustaceans, sea anemones and bivalves were all found on the historic weapons. You could compare it with a reef ecosystem in terms of the abundance of fauna that was inhabiting the area, says Vedenin.

Unexpected Population Density

An mean of more than 40,000 organisms were residing on every square metre of the munitions, researchers documented in their research on the discovery. The nearby seabed was much poorer in life, with only eight thousand creatures on every meter squared.

It is paradoxical that things that are intended to destroy all life are hosting so much marine organisms, says Vedenin. You can see how nature adjusts after a major disaster such as the World War II and how, in some way, marine life returns to the most risky places.

Artificial Features as Marine Environments

Man-made constructions such as sunken vessels, wind turbines, oil rigs and pipelines can offer alternatives, replacing some of the lost habitat. This investigation shows that explosives could be comparably beneficial – the bloom of marine organisms on those in the Lübeck Bay is expected to be duplicated elsewhere.

Between the late 1940s and 1948, 1.6m tons of arms were disposed of off the Germany's shoreline. Countless of individuals placed them in vessels; some were placed in allocated areas, the remainder just thrown overboard during transport. This is the first time scientists have recorded how ocean organisms has adapted.

Worldwide Examples of Marine Adaptation

• In the United States, retired drilling platforms have turned into coral reefs
• Submerged vessels from the World War I have become homes for marine life along the Potomac River in the state of Maryland
• Military vehicle parts that have become habitat to reef-building organisms off Asan beach in Guam

These locations become even more crucial for marine life as the oceans are increasingly denuded by commercial fishing, seafloor dredging and anchoring. Shipwrecks and explosive disposal locations practically serve as protected areas – they are not national parks, but virtually any kind of human activity is banned, explains Vedenin. Therefore a lot of organisms that are usually rare or decreasing, such as the cod fish, are prospering.

Future Considerations

Anywhere armed conflict has happened in the last century, nearby oceans are usually containing explosives, explains Vedenin. Many millions of tonnes of explosive material rest in our seas.

The positions of these munitions are insufficiently mapped, partly because of national borders, secret armed forces records and the fact that documents are stored in old files. They present an detonation and security hazard, as well as danger from the ongoing leakage of toxic chemicals.

As the German government and other countries embark on extracting these artifacts, scientists aim to preserve the habitats that have formed in their vicinity. In the Bay of Lübeck explosives are already being cleared.

It would be wise to substitute these metal carcasses remaining from weapons with certain more secure, some safe materials, like perhaps concrete structures, says Vedenin.

He currently hopes that what occurs in the Bay of Lübeck creates a precedent for replacing material after munitions removal in different areas – because including the most damaging explosives can become foundation for ocean ecosystems.