We don’t normally think about the legacy of World War II in terms of the ordinance that it left behind, that still exists. For example, more than 1.6 million tonnes of unexploded weapons litter the North Sea and Baltic Sea.
A boxy robot crawls across the seabed off northern Germany, reaches through the murky water with a metal claw, and picks up its target: a rusting grenade, dumped into the sea after World War Two. Overhead, another robot swims along the surface, scanning the seabed for more munitions. More robot claws reach into the water from above, plucking bombs and mines from the sediment.
A pilot project backed by the German government will be deploying these and other technologies in a bay in the Baltic Sea this summer, to test a fast, industrial-scale process for clearing dumped munitions that are polluting the North and Baltic Seas. The project is part of a wider 100 million euro ($106.9m) programme by the German government that aims to develop a way to safely remove and destroy munitions littering the German parts of the North and Baltic Seas.
“The problem is that in every marine area where there was a war, or is a war, there are munitions in the sea. And when it’s there for a long time, it can release carcinogenic substances and other toxic materials”, says Jens Greinert, a professor for deep sea monitoring at Christian-Albrecht University in Kiel, Germany, who works at Geomar Helmholtz Centre for Ocean Research in Kiel and is one of the scientists supporting the project. “These munitions are rusting, and our research has shown that over time, they’re releasing more and more carcinogenic, and other toxic, substances, traces of which have been found in fish and mussels,” Greinert says. “The longer we wait, the more they’re going to rust, and the concentration of harmful substances in the water is going to rise. So now is the moment to figure out what to do with this stuff, while the munitions are still intact enough to be grabbed.”
Based on the scientific findings regarding the rusting, leaking munitions, Germany decided it was time to try and remove them from the sea at scale. “Our starting point was to ask, what do we need to do to achieve a healthy marine ecosystem?” says Heike Imhoff, a marine conservation expert at Germany’s environment ministry, which oversees the programme. The long-term goal is to build an offshore platform where the munitions can be destroyed in a detonation chamber, after they are retrieved from the sea in a robot-assisted process, she says.
So far, people have tended to take a piecemeal approach to removing unexploded ordnance (UXO) from the sea. What’s new about the German pilot project is that it combines a range of specially modified technologies, including adapted ROVs and crawlers, and uses them not just to remove individual bombs, but to quickly clear masses of mixed-up munitions from densely littered sites. These dumping grounds are the legacy of Germany’s disarmament. After World War Two, the Allied Forces seized Germany’s conventional and chemical weapons, and dumped entire shiploads of grenades, bombs and other munition into the sea.
“For the past 10, 20 years we’ve been clearing munitions for the purpose of construction – for wind farms, cables, a harbour expansion – and we’ve always cleared it from areas where there isn’t that much to clear, because dumpsites tend to be avoided by those projects,” says Dieter Guldin, chief operating officer at SeaTerra, one of the UXO survey and clearance companies participating in the pilot project. “No one’s ever said before: ‘let’s clear munitions for the sake of the environment, let’s clear it to clean the sea’. This is a totally new approach.”
The problem of dumped munitions goes far beyond the seabed. Children and beachcombers have occasionally picked up seemingly innocent rocks that turned out to be explosives, or pieces of Baltic amber that turned out to be washed-up white phosphorus from incendiary bombs – which can spontaneously burst into flames when warmed, for example in a human hand, or trouser pocket. Walkers, divers and fishing crews in Europe also continue to find old wartime munitions, with hundreds of encounters recorded by the Ospar Commission, a monitoring body, every year.
Unexploded ordnance can also get in the way of infrastructure projects, including Europe’s massive offshore wind farm expansions. “We’ve been involved in over 100 wind farms around the world, and we’ve found unexploded ordnance pretty much on every site,” says Lee Gooderham, managing director of Ordtek, a UK-based consultancy specialising in unexploded ordnance risk management. “The legacy of UXOs is not always dump sites, it’s mines that have drifted, it’s bombs that were dropped in conflict that were not recorded, it’s torpedoes that were fired in conflict that missed their target,” he adds.
The German project’s priority is to clear the dumps for environmental reasons. But in the long term, Greinert, the scientist, says infrastructure projects such as wind farms could also use the process to dispose of munitions quickly without blasting. He says one of the most enjoyable aspects of the German project has been seeing the positive public response: “We’re really working together on this – society, non-profits, scientists and politicians from across the main parties”.
His hope is that the result will be lasting change: “We can remove these munitions from German waters, and then they’re gone, once and for all, and they’re not coming back”.
1.6 million tonnes, and that’s only the North Sea and the Baltic Sea!
