What Lies Beneath – The Toxic Legacy of Post-War Ammunitions Sea Dumping

A stamp from the Faroe Islands depicting a naval ship dumping barrels of chemical warfare agents at sea.Once Upon A Long Time Ago…

Following World War I and World War II, at least three major powers disposed of massive quantities of captured, damaged and obsolete chemical warfare material by dumping them into oceans, seas and lakes around the globe.  Mustard gas, phosgene, lewisite…  Submerged chemical ammunitions pose very serious ongoing environmental problems.

Part of it was accidentally lost at sea as a result of naval or air fight, or shipwrecked.  Sunken vessels tended to settle on the ocean floor largely intact, with the result that the chemical warfare (CW) material remained contained within a small area.

Most of it, however, was deliberately submerged either to get rid of it at a lower cost, to prevent them falling into enemy’s hands, or simply because it was too dangerous for the carrier planes to land with them.  Shells and bombs were sometimes jettisoned unfettered, but more often were loaded as cargo into ships that were sunk by opening sea cocks or holed by artillery fire or torpedoes.

A photograph showing a submerged tank covered in sea algae and barnacles.
Underwater stockpiled tank and ammunitions. Source: Kimo International

Although unfettered materials tended to settle within small areas, some became widely dispersed by currents, tides, and other forces.  As it can be realised, not much care or consideration was given at the time as to the safety and environmental implications of employing such ocean-dumping disposal techniques.


Worldwide Issue

According to United States Department of Defense reports, the US military alone dumped CW agents in waters worldwide on at least 74 occasions between 1918 and 1970.

The jettisoned material consisted either of munitions containing chemicals (such as artillery and mortar shells or bombs) or chemicals encased in some manner in bulk containers made out of metals or cement.

Chemical Weapons Material Dumped at Sea


A screenshot of the Chemical Weapons Material Dumped at Sea Map, focusing on Western Europe coastlines. Image: GoogleMaps/NaturPhilosophie

Map of Chemical Ammunition Sea Dumps in Western Europe

Interactive Google Map available here.

Since the end of the First World War, several countries have dumped at least 1.6 million tons of captured, damaged, obsolete, or unwanted chemical weapons (CW) agents and munitions into the World’s oceans.

The James Martin Center for Nonproliferation Studies developed this map in order to stimulate and support efforts to address the serious threats posed by this CW material.

One of the main areas of concern is the Beaufort’s Dyke, a deep submarine trench, used as a munitions dump, in the Irish Sea.


Beaufort’s Dyke

A map of western Europe showing the locations of submerged ammunitions and chemical agents along the French coastline, in the Channel, North Sea, Irish Sea and Baltic Sea.
This munitions map highlights the extent of munitions dumps with the red stars representing conventional munitions and the green stars chemical munitions.  There is a serious risk of hazardous substances being released from such objects will have a negative affect on the marine environment and will eventually enter the human food chain.  Source: Kimo International

The Beaufort’s Dyke is a submarine depression located in the North Channel of the Irish Sea – a sea trench between Northern Ireland and Scotland.

The dyke is 50 km long, 3.5 km wide and 200-300 metres deep. 

Due to its depth and proximity to the Cairnryan military port, it became the United Kingdom’s largest offshore dump site for conventional and chemical munitions after the Second World War.  In July 1945, 14,500 tons of 5-inch artillery rockets filled with phosgene were dumped in the Beaufort’s Dyke.

Ammunitions have subsequently washed up on beaches near the area.  Notably, in 1995, incendiary devices were discovered on the Scottish and Northern Irish coasts.  According to documents discovered at the Public Record Office approximately two tonnes of concrete-encased metal drums, filled with radioactive laboratory rubbish and luminous paint, were dumped into the Beaufort Dyke, 300 metres deep and 10 kilometres off the Scottish coast.

It was not until 2005 that the British public learned that the Beaufort tank contained tons of ammunitions that were drowned there for over 40 years.

The Ministry of Defence said more than one million tonnes of weapons were jettisoned there, though some are known to have been dumped short of the Dyke in shallow coastal waters.

Most of the weapons dumped in the Beaufort’s Dyke were not designed to go under water.

According to Fellows International, an independent commercial land and underwater Bomb and Mine Disposal (BMD) company, there are sporadic explosions going off all the time, two or three times a month in the Irish Sea.

The oldest ammunitions in the Dyke are losing their ability to withstand corrosion.  They are increasingly getting old and liable to go “bang”Based on the geographical location of munitions dumps, seabed fishermen in the southern North Sea are most at risk from encountering conventional or even toxic munitions.

As time passes, munitions will continue to corrode making the output of dangerous substances inevitable.


Additionally, the lack of knowledge concerning the volume of ammunitions dumps in specific locations makes the clean-up of this problem even more hazardous.  Spontaneous explosions are a serious problem, with the potential to kill marine mammals and damage passing vessels.

A geological map showing the formation and evolution of an isolated submarine valley - The Beaufort's Dyke.
The formation and evolution of an isolated submarine valley – The Beaufort’s Dyke Source: Wiley Online Library

With a maximum depth of 312 metres, the dyke is one of the deepest areas within the European continental shelf.  Integration and interpretation of 450 kilometres of sparker seismic data and full-coverage bathymetric data derived from multi-beam echo sounder surveys allow for the investigation of the formation processes of the Beaufort’s Dyke and the evolution of geomorphological features within it.

The Beaufort’s dyke, formed by composite subglacial processes dominated by subglacial meltwater discharge, is interpreted as a tunnel valley.  The regional isolation of the Beaufort’s Dyke may be explained by the bounding of the North Channel by the bedrock masses of Ireland and Scotland, coupled with the exploitation of structural weakness along a fault plane and presence of halite in the eroded substrate enhancing the erosive potential of the overlying glacier.

Beaufort’s Dyke has probably been maintained as an open feature by strong rectilinear tidal currents.  The morphology of lunate sediment waves and a large parabolic bedform towards the south of the dyke contradict the observed dominant S-N mean hydrodynamic flow recorded within the North Channel, suggesting an alternative hydrodynamic regime either within the dyke or during bedform creation.


Post-War Legacy

A map showing the known locations of post-war sea dumping of chemical warfare agents in the Baltic Sea, and the zones at high risk of environmental pollution.
Known dumping zones of chemical warfare agents in the Baltic Sea. Source: coastalwiki

The poisonous legacy of Nazi Germany – over 300,000 tons of weapons confiscated by the Allies – was dumped between 1945 and 1947 at the bottom of the Baltic Sea. 

The toxic stockpile includes nearly 65,000 tons of mustard gas, nerve agent sarin, and the notorious death camp gas, Zyklon B are beginning to leak, scientists and environmentalists have warned. 

In 1943, mustard gas was released into the waters of Bari harbour.  During the period 1945-1948, the US scuttled at sea approximately 32,000 tons of captured German chemical weapons.  The British dumped approximately 175,000 tons of chemical weapons at sea, with 100,000 tons coming from the captured German stockpile.

A black and white photograph showing naval personnel dumping chemical shells at sea.
Unused poison gas shells being dumped at sea into the Beaufort’s Dyke by naval personnel circa 1950.

During 1955-56, the British dumped a further 17,000 tons of captured German munitions.  During 1956-1957, the British disposed of the remainder of their stockpile of chemical weapons: 8,000 tons of World War II vintage mustard and phosgene munitions.

News reports indicated that ocean dumping in the 1950s occurred mainly in the Irish Sea.  Some of the British dumps in the late 1940s may also have occurred in the North Sea.


Decommissioning Chemical Weapons

From the end of World War I until the 1970s, dumping of chemical weapons at sea was the accepted practice for disposal.  Little documentation of this practice can be found before the mid-1940s.

Previously, the most common disposal methods for chemical weapons were land burial, sea dumping, detonation (firing or exploding the munitions) and open-pit burning.

At the time, scientists argued that the chemical agents would dissolve harmlessly upon contact with water.  Although these methods may have been thought to be quite clever back then (out of sight, out of mind), their danger has since become starkly apparent.

After World War II, ocean dumping resumed in many areas of the globe, including the Baltic Sea, around Japan, in the Adriatic Sea near Bari, and in the coastal waters of the United States.

In 1972, the United States Congress banned the practice of disposing of chemical weapons into the ocean by the U.S.  By that time, 64 million pounds of nerve and mustard agents had already been dumped into the ocean by the U.S. Army.

A black and white photograph showing the dumping at sea of barrels containing chemical warfare agents by the U.S. army.
Barrels of chemical warfare agents being jettisoned at sea by the U.S. army. Source: Oceanhealthindex

According to a 1998 report by William Brankowitz, a deputy project manager at the U.S. Army Chemical Materials Agency, the army created at least 26 chemical weapons dumping sites in the ocean offshore from at least 11 states on both the East and West Coast – Operations CHASE (Cut Holes and Sink ‘Em) and Geranium.  Due to poor record-keeping, however, about one-half of the sites have only their rough locations known.

Buried munitions pose problems environmentally.  Once the munitions begin to corrode and leak, the agents can contaminate the surrounding soil and even get into water sources.

Sea dumping of chemical munitions is another method of disposal that has caused a number of problems.  Some of these dumping operations have occurred in relatively shallow water in the Baltic Sea and off the coast of Japan.  In both of these regions, dumped chemical weapons caused serious problems for the fishing industry.  Fishermen in the Baltic and off the coast of Japan still haul old chemical weapons up in their nets, and are sometimes exposed to still-active agents.

In water, even conventional exploded weapons can be the source of residual pollution from lead, mercury and other heavy metals.  The risk of explosion or sudden extensive leakage are still poorly evaluated and vary according to depth, water salinity, currents, oxygen level and temperature.

Experts in demining and ecotoxicology fear medium-to-long term detrimental effects on the environment and the entire food chain.


Direct Risks

Accidents caused by direct contact with dumped chemical weapons have been reported in the Baltic Sea, the Adriatic Sea, the Pacific Ocean and Japanese coastal waters.

Direct physical contact or disturbance of munitions can occur with various marine activities – fishing, laying cables and pipes, sand and gravel extraction and diving… – but the majority, 59% of all reported encounters, were associated with fishing activities. 

Death and injury can, and have resulted, from the spontaneous explosion of ammunitions.  As recently as in 2005, three fishermen were killed in the North Sea, when a WWII bomb they had taken in their nets exploded on their fishing boat.

Additionally, direct exposure and contamination to chemical weapons, such as yperite, can, and have resulted in severe accidents.  According to the non-governmental organisation Lietuvos, in Denmark where fishermen are financially rewarded for reporting found ammunitions, over 400 such incidents have been recorded in the past two decades.

Mustard Gas (Yperite)


A photograph of an army soldier wearing a protective gas mask, surrounded by a cloud of noxious yellow smoke - presumably yperite mustard gas.
In impure form, such as in CW agents, the gas is brown-yellow, and smells of mustard plants or garlic.

Sulfur-mustard gas are cytotoxic vesicant agents with the ability to form large blisters on exposed skin and lungs.  Pure sulphur mustards are colourless and viscous liquids at room temperature.  Sulfur mustard is not very soluble in water, but it is very soluble in fat, contributing to its rapid absorption into the skin.

Mustard gas was first deployed by the German Army near Ypres, in September 1917.  Yperite – as it became known – is possibly the single cruellest man-made chemical ever developed for its use against man in an armed conflict.  Originally, the chemical was assigned the name LOST, after the two scientists who developed a method for its large-scale production: Wilhelm Lommel and Wilhelm Steinkopf.

It was one of the most lethal of all the poisonous chemicals used during war.  Almost odourless, it took twelve hours to take effect.  Mustard agents could be deployed on the field of battles by means of artillery shells, aerial bombs or rockets, or spraying from warplanes.  Yperite was so powerful that only small amounts had to be added to high explosive shells to be effective.  Once in the soil, mustard gas remained active for several weeks.

Urinary concentrations of the thiodiglycol hydrolysis products of sulphur mustard have been used to confirm a diagnosis of chemical poisoning in hospitalised victims.  However, the presence of 1,1′-sulfonylbismethylthioethane (SBMTE) is considered a more specific marker.  Intact sulphur mustard was detected in post-mortem fluids and tissues of a man who died one week after exposure.

Yperite is vicious.  The skin of victims from mustard gas blistered, their eyes became very sore and they began to vomit.  Mustard gas caused internal and external bleeding and attacked the bronchial tubes, stripping off the mucous membrane.  It was extremely painful and most soldiers had to be strapped to their beds.  It usually took a person four or five weeks to die of mustard gas poisoning.


Indirect Risk

A photograph showing underwater stockpiled rusty ammunition shells.
Underwater submerged ammunitions. Source: Kimo International

There is of course an indirect risk to the food chain.

The locations of some dumping sites are very close to oyster and mussel zones.  Decades or even centuries after the end of conflicts, toxicologists fear that filter organisms – bacteria, fish, shellfish, mussels, oysters, coral reefs, sponges – absorb and bio-accumulate the mercury, lead, carcinogenic arsenic and cadmium that are not degradable elements.

As time passes, shells corrode under the action of saltwater and chemicals begin to leak out.


Bubbling up Under the Surface

Most of the sulphur-mustard gas found in Nazi Germany after World War II was dumped into the Baltic Sea.  Between 1966 and 2002, fishermen have found about 700 chemical weapons – most of which containing mustard gas – in the region of Bornholm.

A photograph showing a canister and wooden crate full of Sprüehbüchse 37 mustard gas.
SprüBü37 or Spray Can 37 – 1937 being the year of its fielding with the German Army.

One of the more frequently-dumped weapons was the “Sprühbüchse 37”.  These weapons contained sulfur mustard mixed with a thickener, which gave it a tar-like viscosity.  When the content of the SprüBü37 comes in contact with water, only the sulfur mustard in the outer layers of the lumps of viscous mustard reacts with water or hydrolyses.  It leaves behind amber-coloured residues that still contain most of the active sulphur mustard.  Upon mechanical breakage of these lumps, with the drag board of a fishing net or by the human hand, the enclosed sulphur-mustard agent is still as active as it had been at the time the weapon was dumped.  When washed ashore, these lumps can be mistaken for amber, which can lead to severe health problems.

WWI artillery shells containing sulphur mustard and other toxic ammunition, as well as conventional explosives, continue to be found in France and Belgium.  These were formerly disposed of by explosion undersea, but since the current environmental regulations now prohibits this, the French government is building an automated factory to dispose of the accumulation of chemical shells.

An aerial photograph showing the location of Badgers Mount ammunition storage dump, in England.
Aerial View of Badger’s Mount ammunition storage dump in England. Source: cryptome.org

A significant portion of the mustard agent stockpile in the United States was stored at the Edgewood Area of Aberdeen Proving Ground in Maryland.  Approximately 1,621 tons of mustard agent were stored in one-tonne containers on the base under heavy guard.  In February 2005, an incineration plant built on the proving ground neutralised the last of this stockpile.  This stockpile had priority because of the potential for quick reduction of risk to the community.  The nearest schools were fitted with over-pressurisation machinery to protect the students and faculty in the event of a catastrophic explosion and fire at the site.

A photograph showing the painful damage and extensive skin blistering sustained by a victim's hand, as a result of exposure to mustard gas.
The painful result of exposure to mustard gas agent.  Source: expeditionwriter

In 2010, a clamming boat pulled up old artillery shells of World War I from the Atlantic Ocean, south of Long Island, New York.  Multiple fishermen suffered from skin blistering and respiratory irritation severe enough to require their hospitalisation.

Last year, in 2014, a collection of 200 bombs were found on the boundary between the Flemish villages of Passendale and Moorslede.  The majority of the bombs were filled with mustard gas.  The bombs were a leftover from the German army, meant to be used in the Battle of Passchendale in World War I – the largest collection of chemical weapons ever discovered in Belgium.

What are we to do with such a highly toxic legacy?