Nazi Bombs, Torpedoes and Naval Mines: How Ocean Creatures Prosper on Abandoned Weapons

In the brackish sea off the Germany's coast lies a wasteland of Nazi bombs, torpedoes and naval mines. Dumped from barges at the end of the second world war and left behind, thousands explosives have accumulated over the decades. They comprise a rusting layer on the low-depth, silty seafloor of the Lübeck Bay in the western part of the Baltic Sea.

Over the decades, the explosive stockpile was ignored and forgotten about. A growing number of visitors came to the coastal areas and tranquil sea for water sports, kite surfing and amusement parks. Underwater, the munitions deteriorated.

Researchers thought to see a lifeless zone, with no life because it was all poisoned, explains a scientist.

When the initial researchers went looking to see what they were doing to the marine environment, the team thought they would find a desert, with no organisms because it was all toxic, says the lead researcher.

What they found surprised them. Vedenin remembers his scientists reacting with shock when the ROV first transmitted footage. This was a memorable occasion, he says.

Thousands of ocean life had settled amid the explosives, creating a regenerated habitat denser than the ocean bottom surrounding it.

This marine city was evidence to the resilience of marine life. Truly remarkable how much life we observe in areas that are expected to be hazardous and risky, he says.

Over 40 starfish had gathered on to one accessible piece of TNT. They were living on iron containers, fuse pockets and carrying containers just centimetres from its volatile core. Fish, crustaceans, anemones and mussels were all observed on the discarded explosives. It's similar to a marine reef in terms of the amount of fauna that was present, states Vedenin.

Remarkable Creature Concentration

An mean of more than 40,000 animals were living on every square metre of the munitions, scientists wrote in their paper on the observation. The surrounding area was much sparser, with only 8,000 individuals on every square metre.

It is paradoxical that objects that are designed to kill everything are hosting so much marine organisms, says Vedenin. One can observe how the natural world adapts after a major disaster such as the World War II and how, in some way, marine life finds its way to the most risky places.

Artificial Structures as Marine Environments

Man-made constructions such as sunken vessels, offshore windfarms, drilling platforms and pipelines can create replacements, replacing some of the lost marine environment. This investigation reveals that explosives could be comparably positive – the bloom of life on those in the Lübeck Bay is likely to be found in different areas.

Between 1946 and the post-war period, 1.6m tons of munitions were disposed of off the German coast. Numerous of workers loaded them in vessels; some were placed in specific sites, others just thrown overboard during transport. This is the first time researchers have recorded how ocean organisms has adapted.

Global Examples of Marine Adaptation

• In the US, decommissioned drilling platforms have transformed into marine habitats
• Sunken ships from the World War I have become environments for wildlife along the Potomac River in the state of Maryland
• Tank tracks that have become habitat to reef-building organisms off Asan beach in Guam

These places become even more important for organisms as the marine environments are increasingly depleted by commercial fishing, bottom trawling and anchoring. Sunken ships and munitions areas practically act as protected areas – they are not official reserves, but virtually any kind of anthropogenic disturbance is prohibited, explains Vedenin. Consequently a numerous of species that are otherwise rare or decreasing, such as the Baltic cod, are flourishing.

Future Considerations

Anywhere warfare has happened in the recent history, adjacent waters are typically littered with weapons, states Vedenin. Millions of tons of dangerous substances lie in our seas.

The positions of these explosives are insufficiently documented, partially because of international boundaries, classified armed forces records and the reality that archives are hidden in historic archives. They create an detonation and security hazard, as well as threat from the persistent emission of poisonous compounds.

As Germany and other countries embark on removing these remains, experts hope to safeguard the ecosystems that have established nearby. In the Lübeck Bay explosives are presently being removed.

It would be wise to substitute these metal carcasses left from weapons with some more secure, some safe objects, like perhaps artificial reefs, states Vedenin.

He currently aspires that what occurs in the Bay of Lübeck sets a model for replacing structures after weapon clearance in other locations – because including the most destructive explosives can become framework for marine organisms.