More than 1.6 million tonnes of unexploded weapons litter the North Sea and Baltic Sea. Remote-controlled seabed crawlers and robots with "smart grabbers" are now cleaning up these toxic munitions.

A boxy robot, controlled remotely, crawls across the seabed off northern Germany, using a metal claw to pick up a rusting grenade. Overhead, another robot scans the seabed for more munitions, with robot claws plucking bombs and mines from the sediment.

This summer, a pilot project supported by the German government will deploy these technologies in the Baltic Sea to test a fast, industrial-scale process for clearing dumped munitions. The project is part of a €100m programme aimed at safely removing and destroying munitions polluting the North and Baltic Seas.

"This interactive map illustrates where dumped munitions have been found. These munitions are rusting, releasing carcinogenic and other toxic substances," says Jens Greinert, a professor at Christian-Albrecht University and Geomar Helmholtz Centre for Ocean Research.

The longer we wait, the more harmful substances will be released into the water. Now is the moment to act while the munitions are still intact enough to be safely removed.