The term submerged munitions refers to situations where munitions have been lost or deliberately dumped into marine, freshwater, or brackish waters, sometimes continental or underground.
These are generally effects of war or military activities.
Regarding the issues, there is a dual risk: sometimes of explosion and, in all cases, in the long term, of as well as chemical contamination of food chains (in the short or medium term).
More than a century after the 1918 armistice, and over seventy years after the defeat of Nazi Germany, hundreds of thousands of tons of these submerged weapons (conventional or chemical) still rest in lakes or on the seabed and remain dangerous. In the event of leaks due to corrosion, they can poison or contaminate animals (fish, shellfish, crustaceans) consumed by humans or farm animals (in the form of fishmeal and oils).
Given the high costs of addressing the problem and the lack of consensus on solutions.Fokin, AV and Babievsky, KK, ‘Chemical "Echo" of the Wars’, in ‘Sea-Dumped Chemical Weapons: Aspects, Problems and Solutions’, Ed. AV Kaffka, Kluwer Academic Publishers, Dordrecht, 1996, p. 29-33. and risk measurement, its consideration seems to have been postponed until the 2000s.
Nature and origin of submerged munitions
These can be chemical or conventional munitions.
Often, they were deliberately submerged to dispose of them at lower cost, to prevent them from falling into enemy hands, or because they risked exploding or leaking due to their degraded state.
Another portion, which is not the most significant, was simply accidentally lost at sea following battles, shipwrecks, scuttlings, or beachings.
Some areas distributed somewhat everywhere in the world were reserved for dropping heavy munitions (bombs, torpedoes, land mines) not used during aborted missions due to weather or counter-orders. It was too dangerous for aircraft to land with their munitions, or these would have excessively increased their fuel consumption, preventing them from returning safely. These munitions were therefore dropped into the sea before returning to base, sometimes quite close to the coasts. These jettison zones are theoretically prohibited for navigation (air or sea). They mainly date from World War II, which inaugurated the method of massive aerial bombings. In the OSPAR or Channel/North Sea zone, there are at least three: near the English coast, in the Thames estuary, and another in the Strait of Dover. For example, approximately 100,000 incendiary projectiles and nearly two hundred "Cookies" were reportedly dropped by a fleet of 138 Lancaster bombers of the RAF on December 15, 1944, in the Channel, following the attack on Siegen (east of Cologne), aborted due to fog.Little Known Facts of World War II "Glen Miller disappears without a trace" A significant portion of these munitions did not explode and likely still rest on the bottom, at −35 m in this "Southern Jettison Area" ("jettison" in English refers to the act of throwing an object or waste overboard from a boat, submarine, plane, or helicopter; it can also refer to an aircraft dumping unconsumed fuel before a safe or emergency landing. In this case, predetermined jettison zones (called FJA "Fuel Jettison Area" by English speakers). The "Southern Jettison Area" lies under the current ascending lane of Channel maritime traffic, according to Michel Dehon.Michel Dehon; Chroniques Historiques – Munitions sous la Manche (cyanopale-histoires)) Its center is at 50°15 N and 0°15 E, with a radius of 9 km. These three RAF aerial jettison zones were not taken into account in the inventory made for OSPAR, notes Michel Dehon.
Some marine and lake sites have been regularly used as target practice areas or for testing, including the special case of nuclear tests. Many unexploded ordnance have thus been lost during military tests or exercises and, in the case of misfires, not all have been recovered.
Some countries (maritime or not, such as Switzerland) have used lakes and wetlands as exercise and dumping sites for obsolete munitions.
In water (lake, sea, or closed wetland ...), even conventional munitions that exploded on impact can be a source of pollution by lead, mercury, or other metals.
Submerged explosives The mention "Explosives submerged" on some nautical charts refers to underwater dump sites established since the end of World War I, but many deposits seem not to have been indicated on these charts. Since then, some deposits have also been partially dispersed by currents, tsunamis, and fishing trawls.
These particular "objects" seem legally assimilable to "toxic or hazardous waste" likely to release into the environment many pollutants, including eutrophying agents and some very toxic products, in dispersed quantities (), most often and initially in low doses, but chronically. The risks of explosion or sudden and significant leakage are still poorly assessed and could vary depending on depth, salinity, currents, oxygen levels, and water temperature.
The consequences encompass the domains of economy, environment, public health, civil protection, military affairs, and foresight. The impacts feared by experts in demining and ecotoxicology are mainly medium and long term and concern the entire food pyramid.
Freshwater Few data are published, but ancient munitions have been massively found, for example, in Lac de Gérardmer in France or in the (120 m vertically) from which the springs of the Loue flow, in the Doubs. In Switzerland, one lake in two has reportedly received them, including large lakes such as Lake Thun, Lake Brienz, and Lake Lucerne.
Risks and dangers
Risks of direct contact A first, direct risk is that of death or injury following the spontaneous or accidentally triggered explosion of a munition. Thus, recently in 2005, 3 fishermen were killed in the southern part of the North Sea by the explosion, on their fishing boat, of a World War II bomb caught in their nets.OSPAR Commission, 2010 Health Check According to the OSPAR Commission, "The pressure exerted by the loud noise produced by spontaneous or controlled munition explosions can injure or kill certain marine mammals and fish. It has been reported that porpoises have been killed within a 4 km radius of explosions and others have suffered permanent hearing damage within a 30 km radius".
A second risk is that of exposure to mustard gas, the war toxicant that has been most massively dumped at sea. According to Andrulewicz (1996),‘Sea Dumped Chemical Weapons: Aspects Problems and Solutions’ cases of capturing mustard gas in the form of viscous lumps or contamination of nets during bottom trawling have been recorded, particularly in the western part of the Polish coast, which is consistent with available data on dump sites and sea dumping routes. Some cases have been reported by the press:
Doyle (2004)for Reuters, Horten, Norway, January 26, 2004 quotes Danish fisherman Walther Holm Thorsen: "It was terrifying. The pain was unbearable, and my hands were blistered all over"; He was 15 years old (in 1969) when he threw back into the Baltic Sea a pierced gray canister caught in the meshes of his trawl (...), the pain came in the middle of the night, a few hours after he and another crew member had rinsed the oily substance off the fish. They had no idea it could be mustard gas. Thorsen spent three months in the hospital, and his hands are still heavily marked, despite a skin graft. "Working as a fisherman is difficult today – I often feel like my hands are frozen", he says. According to the NGO Lietuvos,Lietuvos.org, accessed April 28, 2012 in Denmark, where financial incentives reward fishermen who report munitions to the army for recovery, more than 400 such incidents have been recorded in the last two decades. According to Mitretek Systems, accidents due to contact with submerged chemical weapons have been reported in the Baltic Sea, the Adriatic Sea, the Pacific Ocean, and Japanese coastal waters. In the United States, where chemical munitions were also submerged before the 1970s, for example, from 2004 to 2012, three cases of exposure to mustard gas were reported to the CDC during dredging of seashells intended to decorate a driveway, and twice during commercial clam fishing (cases that could therefore have also affected final consumers if they had not been detected). Most often, these are fishermen who have inadvertently touched objects contaminated with mustard gas in their nets. Often, accidents recur in the same areas. In cold water, mustard gas hydrolyzes on the surface but forms a viscous mass that can persist for decades or longer.Hart, J, ‘A Review of Sea-Dumped Chemical Weapons’, presented at ‘The Environment and the Common Fisheries Policy, Threats to and Constraints on Sustainability’, (Greenwich Forum), The Royal Society, January 27, 2000. Some forms of mustard gas are particularly insoluble in water, including, according to Professor Paka, mustard gas improved for use in extreme cold ("winter mustard", intended for use in Russia, among others) with a formulation containing 37% arsenic as an additive; 20% of the mustard gas produced in Germany by the Nazis was of this type.
Toxic leaks It takes about 80 years for a munition to start leaking. The corrosion of munitions is a source of delayed toxic leaks in time and space, still poorly assessed, first because the situation is somewhat "new" in environmental history, but also because in Europe, secrecy has long surrounded marine munitions dumps; it was not until 2005 that the English public learned that the Beaufort's Dyke contained more than a million tons of munitions submerged there over more than 40 years. Concerning France, which seems to be one of the countries most affected in the world by munitions immersions, it was only in 2005 that a first official map, imprecise and without quantitative data, was published (with a five-year delay since these maps were to be published before 2000, in application of the London Convention and in accordance with the commitments of the member countries of the OSPAR Commission).
The authorities responsible for these immersions seem to have long thought that there would be degradation followed by dilution of chemical toxins. However, at least in cold waters, most of the toxins from munitions have remained perfectly active after 80 years, some are neither degradable nor biodegradable (mercury, for example), and they can be quickly reconcentrated by filter-feeding organisms and the food chain.
Several types of indirect risks must be taken into account, sometimes adding their effects in the form of contaminations of the ecosystem and/or marine materials (gravel pits, sand extraction) likely to be used.