Greenpeace Germany campaigners Thilo Maack (L) and Niklas Schinerl monitor the action from on board the "Beluga II". Greenpeace activists sink granite rocks from the "Beluga II". The activists use the boulders to protect the marine reserve Adlergrund from destruction by the bottom trawls of industrial fishermen. Fishermen plough through the seabed quite legally even in explicitly protected areas, thus destroying the ecosystem.