Young people declare war on marine litter
Support from the Federal Environment Agency

Especially plastic waste is a problem for the seas because plastic does not rot.
Source: Heike Scheub
Estimates claim the amount of litter in the world's oceans to be up to 142 million tonnes and that there are up to 18,000 pieces of plastic waste for every square kilometre of ocean surface. Beaches along the southern North Sea have an average of 236 pieces of waste on 100 metres of coastal strip; the North sea bottom is believed to have an average 11 kilogrammes of litter per square kilometre. Up to 10,00 fishing nets are thought to be lost in the Baltic Sea every year, where they continue to 'fish' adrift and are able to kill for a long time.