The Cleaver Bank is an open-sea reef in the terms of the European Habitats directive and has been registered with the European Union as a Natura 2000 site. The bank originated as a terminal moraine of a glacier during one of the Ice Ages.[2]
The surface of the bank partly consists of gravel and larger cobbles. Due to the relatively great depth of the Cleaver Bank, the soil is only seldom, in very heavy weather, moved by wave action.[3] Because the gravel is relatively poor in silt and the transparency is great, there is enough light to allow for the growth of calcareous red algae.[3] The benthic fauna on the bank contains species that live on a hard substrate, such as sea anemones and polyps.[4] Rare species living on Cleaver Bank are Thracia convexa and the Rayed artemis. The bank is used by herring for spawning.[4] In addition, the soft coral type dead man's finger is found here.
In 2001, the Dutch government considered the Cleaver Bank as a potential area for mining gravel.[5] After making an Environmental impact assessment the plan was abandoned.[6] The Cleaver bank is in 2015 considered for protection as a Marine protected area. The Greenpeace organisation considered the actions of the Dutch government in this direction too slow and sunk some large boulders on the seabed in May 2015 to increase the nature value.[7] Dutch fishers lifted the boulders on 16 June 2015, because they were afraid the boulders would damage their fishing gear.[8]
