Over the past years, various countries, including France, have focused on producing an inventory of dumped ammunition in their territorial waters and exclusive economic zone.
In France, the two main known areas are the Fosse des Casquets in the Channel and an area off the island of Sein, where 12 vessels and 70 tonnes of chemical ammunition were dumped before 1980.
In 2004, the OSPAR Convention for the protection of the North-East Atlantic launched a vast inventory of knowledge on the subject in the North Sea and Baltic Sea.
It has listed 140 dumping locations from Iceland to Gibraltar, including 30 comprising chemical weapons, and has identified 1879 incidents of munitions being discovered by fishing boats or dredgers between 2004 and 2009, i.e. almost one for every working day.
Of these encounters, 1821 were sufficiently well located to be marked on a map, which reveals a high concentration in the southern part of the North Sea, between Great Britain and the Netherlands.
The Baltic Marine Environment Protection Commission (Helsinski Commission, in short HELCOM) estimates that some 40,000 tonnes of munitions have been dumped in the Baltic Sea, including an estimated 13,000 tonnes of chemical weapons.
The James Martin Center for Nonproliferation Studies (CNS), in Monterey, has produced a world map showing 127 dump sites and reports that there are at least 16,000 tonnes of chemical weapons in the waters of the former USSR.