Interview: Dangerous legacy - munitions in the North and Baltic Seas to be cleared
Lasse Johannsen
· 02.08.2023
At the end of the war in spring 1945, a gigantic munitions dump began in German waters. To this day, around 1.6 million tonnes of old munitions lie at the bottom of the North Sea and Baltic Sea. These are now to be successively cleared before the explosives can pollute the marine environment and enter the food chain. Alexander Bach, a consultant at the "Munitions in the Sea" special unit of the Schleswig-Holstein Ministry of the Environment, explains the background in an interview with YACHT.
Mr Bach, the federal government has launched an emergency programme to clear munitions and has made 100 million euros available for this purpose. How did this come about now, almost 80 years after the end of the war?
I believe that what we are seeing now is the result of the work of the last 15 years.
In YACHT 6/2012, we conducted an interview with the authors of the report "Munitions pollution in German marine waters", which was published at the end of 2011 as the result of a federal-state measurement programme ...
... an inventory of what lies in the German waters of the North Sea and Baltic Sea. Recommendations were made at the time on how to deal with it. However, the assessment was that there was no widespread danger. In the meantime, the view has changed a little, with investigations by the Geomar Helmholtz Centre for Ocean Research in Kiel finding explosives in every water sample.
The German waters are completely contaminated by the munitions?
Not always in high concentrations, the greatest contamination is in the dumping areas. But munitions residues are now being detected everywhere. This realisation and the results of the Kiel Munition Clearance Week, which took place here in September 2021, have shaken politicians awake.
What kind of event is this?
One of the largest trade fairs on the subject, at which 700 international experts discussed the new overall assessment and at which members of the Bundestag and employees from the various administrative authorities were present or informed about it. I believe this was a decisive contribution to the budget funds finally being released in autumn 2022. And the decision to make a fair contribution to this in the long term is also reflected in the Schleswig-Holstein coalition agreement.
How much ammunition is currently in the sea?
The distribution is still as it was determined in 2011. We know the dumping areas and other areas contaminated with munitions that were already mapped in the 2011 report. In the German North Sea and Baltic Sea, i.e. both the territorial sea and the Exclusive Economic Zone, this amounts to a total of around 1.6 million tonnes of munitions contamination. Of this, 1.3 million tonnes are in the North Sea and 300,000 tonnes in the Baltic Sea.
And what's new about the overall rating?
The knowledge about how the ammunition is located down there.
And what follows from this?
Some of it is rusted through, but some of it is still almost as good as new. The rusted-through ammunition causes problems for our environment because the explosives can get into the water and thus into the food chain. Closed munitions don't worry us quite as much - but in the dumping areas we can see that they are sometimes stacked in layers. And that is a huge challenge when it comes to salvaging.
What exactly is there in the way of old munitions?
The scuttling areas contain everything that war has thrown up. From torpedoes to bombs, sea mines, artillery ammunition and grenades to small arms ammunition.
Chemical munitions too?
Only a small proportion, around 5,000 tonnes. Of which 90 tonnes in the North Sea, the rest in the Baltic Sea. The affected dumping area is in the Little Belt, but as the loading took place in Flensburg and dumping began on the way to the dumping area, we include it in the German munitions waste.
How has the munitions contamination been dealt with since the 2011 report?
The report was updated. A central reporting office for ammunition finds was set up at the Maritime Safety Centre in Cuxhaven. The centre began operations in 2012. Since then, all reports that have anything to do with munitions in the sea have been sent there. For example, about finds during dredging work in offshore wind farms. Or by the munitions clearance services when they are called to a site. This gives us a good overview of what is happening in the waters. We have also done a lot of mapping with partners from the scientific community. We can now provide almost photorealistic information about the dumping areas in the Bay of Lübeck and the Kolberg Heath, what kind of munitions are there and what condition they are in. We have also developed methods for monitoring which pollutants are entering the marine environment and how many. We couldn't do that before. We can now tell quickly and very precisely when explosives have been released from the munitions. Most of the results of these investigations are published in the reports available on the ammunition-in-the-sea.com can be viewed.
How great is the actual danger posed by the munitions in the sea?
Wherever there is an immediate danger to life and limb, the Explosive Ordnance Clearance Service and the Waterways and Shipping Administration take action within the scope of their responsibilities. If, for example, ammunition is found in a shipping lane with the potential to endanger shipping, it is cleared.
And for the marine environment?
During so-called mussel monitoring in the dumping areas, we found concentrations at which juvenile fish were dead after 24 hours in laboratory tests. But that was ten centimetres away from exposed explosives. The measured values already drop at a distance of one to two metres. Even the wide-area distribution does not occur as quickly as one would imagine. We have therefore not yet been able to detect any harmful levels of contamination outside the dumping areas. This means that fish and mussels can still be eaten, as they are not caught in dumping areas. But we are investigating the effects on the food chain.
There are repeated warnings about beach finds that turn out to be old ammunition.
This happens again and again. In Schleswig-Holstein, mostly in the form of ammunition fragments. In Mecklenburg-Western Pomerania, white phosphorus can also be found, which looks similar to amber and comes from incendiary bombs in dumping areas located there. If you are not sure whether you have really found amber, put the beach find in a tin pot, and if it is dry after a day and has not yet ignited, it is usually not phosphorus.
To what extent is your special unit internationally networked?
We work intensively with Helcom, the organisation for marine environmental protection in the Baltic Sea. There is a network of experts called Submerged. It has now produced an assessment of the munitions contamination in the Baltic Sea as a whole. But there is still no actual, standardised picture of the situation. But at least we have an overview of the situation in the Baltic Sea. And we are trying to establish monitoring for the entire Baltic Sea as part of this expert network. Waste munitions are simply an international issue.
What will be different with the immediate action programme?
So far, evacuations have only been carried out in individual cases. For example, in the event of imminent danger or construction projects. What we want now is to really recover and dispose of mass.
How does this work?
This is currently being considered. We can use existing technology for salvage, but what we still lack is the corresponding disposal capacity. The entire process chain needs to be considered. From detection and defusing to recovery and disposal. These four steps can be taken individually or combined.
Why is this task only being tackled now?
There are many reasons for this. Everything that covers the sea with its blue carpet is no longer visible. But after the Second World War, there were also relatively quick actions to clear the munitions. Not to dispose of it, but to blow it up or take it out and dump it somewhere else. And then there was a time when the issue was forgotten and there was a certain diffusion of responsibility. And then, of course, in the end it is always a question of money. But now we have reached a point where everyone involved says that we want to do this together.
How is the risk minimised during recovery?
It starts with divers using cameras to help find out what condition the ammunition is in. Is it rusted through, is there still a detonator on it, is the explosive possibly already visible? It does not become less dangerous over the years under water, but even more sensitive to impact.
Do water sports enthusiasts have anything to fear if work has begun to systematically salvage the old stock?
No. Restricted areas are set up with a sufficiently large safety radius so that neither water sports enthusiasts nor divers or shipping are endangered. And if blasting is unavoidable, appropriate safety measures will be introduced. However, we do not assume that this will be the case when clearing the area.
Are there areas where skippers are particularly at risk?
If the nautical chart says "unclean, ammunition", then something has been found there or you know that ammunition has been dumped there. It usually also says "Fishing and anchoring prohibited", and that's exactly what you shouldn't do there. Anything that is in any way likely to touch the bottom and release ammunition should be avoided. I don't know of any cases where an anchor has set off old munitions, but two years ago a fisherman had a mine in his net off the British coast, which then set off, resulting in personal injury. So the danger is definitely there.
Why does this happen so rarely with the enormous quantities of old munitions?
Because the fishermen today still know exactly where the old munitions are. We can even clearly see from underwater mapping that the trawling tracks run right round the dumped munitions.
In your opinion, what are the greatest dangers that still emanate from old munitions today?
Actually rusting through. The thin-walled ammunition is often already so rusted through that the explosives are exposed. The amount of explosives that can come into contact with the marine environment is increasing, and with it the pollution and the likelihood of pollutants entering the food chain.
Will there be a time when everything is cleared?
I really hope so, but I'm afraid that I won't live to see it (laughs). It is a task for generations. A well-adjusted disposal plant might manage three tonnes a day. With 1.6 million tonnes, it's easy to work out how long that takes.
Which areas are already the best cleared today?
The main shipping routes and fishing areas were cleared immediately after the dumping. For example, the Kiel-Baltic Sea route, the Kiel-Flensburg route or the Fehmarnbelt. After all, people were working there and they wanted to protect them. What was not done was to clear the dumping areas, they were left as they were.
Was or is there co-operation with the Allies at the time?
No, they have their own problems with contaminated sites. As part of our archive research, however, we use the records of the Allies, because they recorded very precisely what was loaded onto which ship when and where, and where it was supposed to go.
Finally, do you have any practical recommendations for our readers?
You can find information on the website Munition im Meer. There you will also find recommendations on what to do if you find ammunition on the beach. Because whenever you find something unknown there, caution is advised.
- Further information: munitionclearanceweek.org
