World War II Bombs, Torpedo Heads and Naval Mines: How Ocean Creatures Flourishes on Discarded Weapons

In the slightly salty waters off the German shoreline sits a collection of World War II explosives, torpedoes and mines. Discarded from barges at the conclusion of the second world war and left behind, countless munitions have become matted together over the decades. They comprise a rusting layer on the low-depth, silty ocean floor of the Lübeck Bay in the western part of the Baltic Sea.

Over the decades, the Nazi arsenal was ignored and forgotten about. A growing number of tourists traveled to the coastal areas and calm waters for water sports, kite surfing and entertainment venues. Beneath the surface, the munitions deteriorated.

Researchers thought to see a lifeless zone, with nothing living there because it was all contaminated, explains Andrey Vedenin.

When the first scientists went searching to see what they were affecting to the marine environment, researchers expected to see a lifeless zone, with nothing living there because it was all poisoned, states a scientist.

What they found surprised them. Vedenin remembers his colleagues exclaiming in amazement when the underwater vehicle first transmitted footage. This was a remarkable experience, he recalls.

Countless of sea creatures had settled among the explosives, creating a revitalized habitat more populous than the seabed nearby.

This underwater metropolis was testament to the persistence of marine life. It is actually surprising how much life we find in areas that are considered dangerous and risky, he says.

In excess of 40 starfish had gathered on to one visible fragment of TNT. They were living on iron containers, detonator compartments and storage boxes just centimetres from its volatile core. Fish, crabs, sea anemones and mussels were all discovered on the discarded explosives. You could compare it with a reef ecosystem in terms of the quantity of animal life that was there, states Vedenin.

Surprising Creature Concentration

An mean of more than 40,000 organisms were residing on every square metre of the explosives, experts documented in their paper on the discovery. The nearby seabed was much poorer in life, with only 8,000 individuals on every meter squared.

It is surprising that items that are designed to destroy all life are hosting so much marine organisms, states Vedenin. You can see how nature adapts after a devastating occurrence such as the second world war and how, in some way, marine life returns to the most risky places.

Artificial Features as Ocean Habitats

Artificial constructions such as shipwrecks, wind turbines, oil rigs and pipelines can create substitutes, restoring some of the lost habitat. This study reveals that munitions could be similarly beneficial – the bloom of marine organisms on those in the Bay of Lübeck is expected to be repeated in other locations.

Between the late 1940s and the post-war period, 1.6 million tons of munitions were dumped off the German coast. Countless of workers placed them in boats; some were placed in designated areas, others just thrown overboard during transport. This is the first time researchers have recorded how ocean organisms has reacted.

Global Examples of Marine Transformation

• In the US, retired oil and gas structures have transformed into reef ecosystems
• Submerged vessels from the first world war have become environments for marine life along the Potomac River in Maryland
• Tank tracks that have become home to coral off Asan in Guam

These areas become even more valuable for organisms as the seas are increasingly depleted by commercial fishing, bottom trawling and anchoring. Sunken ships and explosive disposal locations essentially function as protected areas – they are not national parks, but almost any kind of human activity is banned, explains Vedenin. As a result a lot of organisms that are otherwise scarce or decreasing, such as the Baltic cod, are thriving.

Future Issues

Wherever warfare has happened in the past 100 years, adjacent waters are typically littered with munitions, says Vedenin. Millions of tonnes of dangerous substances remain in our oceans.

The sites of these munitions are insufficiently documented, in part because of sovereign limits, classified defense data and the fact that records are hidden in old files. They create an detonation and safety danger, as well as risk from the persistent release of poisonous compounds.

As Germany and different states embark on clearing these artifacts, scientists plan to protect the marine communities that have developed around them. In the Bay of Lübeck weapons are currently being removed.

It would be wise to substitute these iron structures left from weapons with certain more secure, some safe materials, like possibly concrete structures, says Vedenin.

He presently aspires that what happens in the Bay of Lübeck establishes a precedent for substituting habitats after weapon clearance in different areas – because even the most harmful weaponry can become framework for ocean ecosystems.