World War II Explosives, Torpedo Heads and Mines: How Marine Life Thrives on Dumped Armaments

In the slightly salty sea off the German coast sits a collection of Nazi bombs, torpedo heads and naval mines. Discarded from barges at the end of the second world war and neglected, countless explosives have fused into clusters over the decades. They create a corroding carpet on the shallow, muddy ocean floor of the Lübeck Bay in the western tip of the Baltic Sea.

Over the decades, the explosive stockpile was ignored and forgotten about. A increasing amount of tourists traveled to the sandy beaches and tranquil sea for jetskiing, kite surfing and amusement parks. Beneath the surface, the munitions decayed.

We initially expected to see a desert, with no organisms because it was all poisoned, says a scientist.

When the first scientists went searching to see what they were doing to the marine environment, some of us expected to see a desert, with no life because it was all contaminated, says the lead researcher.

What they found astonished them. Vedenin recalls his colleagues reacting with shock when the underwater vehicle first relayed pictures. That moment was a great moment, he notes.

Thousands of sea creatures had made their homes among the munitions, developing a regenerated ecosystem more populous than the ocean bottom surrounding it.

This marine city was proof to the resilience of marine life. Truly surprising how much life we find in places that are considered toxic and harmful, he explains.

Over 40 sea stars had clustered on to one accessible fragment of TNT. They were living on steel casings, detonator compartments and transport cases just a short distance from its volatile core. Fish, crustaceans, anemones and mussels were all observed on the historic weapons. It's similar to a marine reef in terms of the quantity of animal life that was present, states Vedenin.

Remarkable Creature Concentration

An mean of more than 40,000 animals were dwelling on every square metre of the explosives, scientists documented in their study on the finding. The nearby seabed was much less diverse, with only 8,000 organisms on every square metre.

It is paradoxical that things that are meant to kill all life are attracting so much marine organisms, says Vedenin. You can see how nature adjusts after a catastrophic event such as the World War II and how, in certain respects, marine life establishes itself to the most hazardous locations.

Artificial Features as Ocean Environments

Man-made constructions such as sunken vessels, wind turbines, oil rigs and undersea pipes can provide substitutes, compensating for some of the lost habitat. This study demonstrates that munitions could be comparably advantageous – the bloom of marine organisms on those in the Lübeck Bay is likely to be repeated in other locations.

Between the late 1940s and 1948, 1.6m tonnes of weapons were disposed of off the German shoreline. Thousands of individuals placed them in vessels; some were placed in specific locations, others just thrown overboard while traveling. This is the initial instance experts have documented how ocean organisms has reacted.

Worldwide Examples of Marine Adaptation

• In the US, decommissioned drilling platforms have become coral reefs
• Submerged vessels from the first world war have become habitats for creatures along the Potomac River in Maryland
• Tank tracks that have become home to coral off Asan beach in Guam

These places become even more valuable for wildlife as the seas are increasingly depleted by commercial fishing, seafloor dredging and boat mooring. Shipwrecks and explosive disposal locations effectively serve as refuges – they are not official reserves, but virtually any kind of human activity is prohibited, says Vedenin. Consequently a lot of marine species that are usually scarce or declining, such as the Baltic cod, are flourishing.

Future Issues

Wherever warfare has happened in the last century, adjacent waters are usually strewn with weapons, states Vedenin. Millions of tonnes of volatile compounds rest in our oceans.

The sites of these munitions are insufficiently mapped, partially because of sovereign limits, restricted armed forces records and the situation that records are buried in historical records. They create an detonation and safety risk, as well as risk from the continuous emission of hazardous substances.

As Germany and other countries start clearing these artifacts, scientists plan to protect the habitats that have formed nearby. In the Lübeck Bay explosives are already being removed.

We should replace these iron structures left from munitions with some more secure, some non-dangerous structures, like maybe man-made habitats, suggests Vedenin.

He currently wishes that what happens in the Bay of Lübeck sets a model for replacing material after weapon clearance in other locations – because also the most destructive explosives can become framework for marine organisms.