Kiel Munition Clearance Week: Why munitions must be removed from the sea

Contents

Munitions contamination in the German Baltic and North Seas is more widespread than previously assumed. At the second “Kiel Munition Clearance Week”, experts want to find solutions for clearing the munitions that were either dumped or sunk by ships after the Second World War. Representatives from numerous federal and state authorities, the German Navy and international navies, industry, science and the environmental sector from 16 countries will attend.

The specialist conference, which is being organized by the Schleswig-Holstein Ministry for Energy Transition, Climate Protection, Environment, and Nature in cooperation with the Kiel-based technology company north.io GmbH, will focus on various approaches to removing munitions from the seabed and protecting critical infrastructure.

Between 1.3 and 1.6 million tons of munitions and more than 5,000 tons of chemical warfare agents lie at the bottom of the North Sea and Baltic Sea alone – the latter were often dumped in deeper waters, according to Prof. Jens Greinert, head of the Deep Sea Monitoring working group at the Helmholtz Centre for Ocean Research Kiel (GEMOAR). While the oceans are being used more and more – for offshore wind farms or the construction of pipelines, for example – the risk posed by the pollutants released in the process is also increasing.

Rust alone is already a burden on the oceans, but the substances released are even more so. According to the experts, there are not only individual, clearly defined dumping areas. Findings are also regularly made outside the known dumping sites. Ocean currents disperse munitions and their residues, meaning that even distant coastal areas can be affected. Politicians have also recognized this and for the first time launched an “Immediate action programme for munitions in the North Sea and Baltic Sea” with 100 million euros. The aim is to systematically recover munitions from the North Sea and Baltic Sea and dispose of them in an environmentally friendly manner – a pilot project has already been carried out in the Bay of Lübeck. The Federal Ministry for the Environment even speaks of a “carpet of bombs”.

Empfohlener redaktioneller Inhalt

Mit Ihrer Zustimmung wird hier ein externes YouTube-Video (Google Ireland Limited) geladen.

YouTube-Video immer laden YouTube-Video jetzt laden

Ich bin damit einverstanden, dass mir externe Inhalte angezeigt werden. Damit können personenbezogene Daten an Drittplattformen (Google Ireland Limited) übermittelt werden. Mehr dazu in unserer Datenschutzerklärung.

Not only traces, but also relevant quantities of TNT and its degradation products can be detected in mussels and fish – particularly in the vicinity of old ammunition dumps. Old ammunition from storage sites was transported to dumping areas on fishing boats and the like, explains Greinert. However, munitions were often also dropped outside these areas. “The [...] navigation at sea was probably not as precise as it is today and then it was probably also the case that the fishermen perhaps wanted to be home a little earlier,” says Greinert.

Baltic Sea and North Sea contaminated with munitions

According to the experts, hydroacoustic mapping of the seabed using echo sounders revealed that there are many munitions in the dumping areas, but also a lot outside. According to Greinert, “the entire German Baltic Sea must therefore be regarded as contaminated with munitions, [...] with hotspots in the dumping areas”. This is also the case in the North Sea. There is a risk that rusting munitions caps will release harmful substances. Together with other, already existing stress factors, this could quickly lead to a tipping point, even if the TNT load alone would not cause this.

Large bombs, the Fieseler Fi 103, also known as “V1”, were also thrown into the sea in the Bay of Lübeck in large numbers after the Second World War. V1 bombs contain around 800 kilograms of explosives. Over time, the metal shells of these bombs rust through. According to Greinert, the explosives inside then look like a yellow, holey cheese and dissolve in the water. According to Greiner, the problem is if many bombs rust through at the same time in the coming years and the amount of toxic substances in the sea increases rapidly. It is also dangerous for the environment, as substances such as TNT, RDX and HDX can cause cancer or damage genetic material. It is difficult to predict exactly when this will happen, says Greiner.

To identify the explosives, the researchers carry out so-called “munitions surveys”, also known as UXO surveys (Unexploded Ordnance), and systematically search the seabed for munitions remnants. Commercial companies do this before building offshore wind farms, for example. According to Dr. Matthias Brenner, a research associate in the Ecological Chemistry Section at the Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven, the contamination is “very hazardous to health”, especially due to high concentrations of TNT.

The greatest risks lie in the chronic pollution of ecosystems and the accumulation in the food chain. There is already evidence that mussels from particularly affected areas pose a health risk to humans. There are also indications of an increased cancer rate in fish living in contaminated areas.

Carcinogenic substances in the food chain

The heavy metal pollution in the sea is one of the reasons why fish should generally only be eaten twice a week, explains Dr. Jennifer Strehse, research associate at the Institute of Toxicology and Pharmacology for Natural Scientists, Faculty of Medicine, Christian-Albrechts-Universität zu Kiel. Conventional ammunition contains toxic heavy metals such as mercury and lead. Dumped chemical munitions contain mustard gas, phosgene, sarin or tabun, among other things, as the Science Media Center reports.

The mussels in the dumping areas should not be eaten because of the pollutants released by the TNT and its conversion products on the seabed. “The risk of cancer should be particularly emphasized,” says Strehse. In fish that do not come directly from munitions dumping areas, the concentration is very low, but traces are still measurable. The situation will be different if the munitions “lose more and more of their metal shells over the next few decades [...] and these substances are released further and further into the sea”. According to Brenner, studies have also shown liver abnormalities in fish that were found in the direct vicinity of old munitions.

Diving robots with gripper arms and crawlers

According to Greiner, the recovery of potentially explosive bombs is a challenge, even if the methods of recovery are constantly improving. It is difficult to retrieve a whole pile of ammunition from the water. An explosion could destroy technical equipment, and personal injury would be even worse. Among other things, recovery platforms on the water, diving robots with gripper arms and crawlers that walk along the seabed are used.

There is still a lot of blasting going on, says Strehse. Underwater, such blasting, which has taken place in other EU countries in the past, for example against better knowledge, could cause contamination and harm underwater creatures. Harbor porpoises, for example, have very sensitive hearing that can be impaired by the blast wave, Strehse explains. Scandinavian countries are more aware of the problems.

(mack)