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Bundesamt für Naturschutz

The Kadet Trench Nature Conservation Area

The Kadet Trench Nature Conservation Area (NCA), which is only about 100 km² in size, is located in the western Baltic Sea about 20 km north of Rostock and about 10 km west of the Darss Peninsula. The Kadet Trench is actually a whole system of trenches cutting into the submarine till ridge of the Darss Sill at depths of up to 32 m. About 70% of the water exchange between North Sea and central Baltic Sea passes through this trench system. Due to aperiodic inflow of saltwater from the North Sea, the area is subject to strong fluctuations in its salinity level. The species-rich benthic communities living here therefore have a relatively high salt tolerance. Some benthic species (e.g. sea anemones) have their eastern distribution limit here.

Facts Kadet Trench Nature Conservation Area

Natura 2000 site placed under national protection as an NCA in 2017 

Fact sheet

HD site
Kadet Trench
EU Code: DE 1339-301


Habitat types


approx. 23 km²


Harbour porpoise (Phocoena phocoena)

Most important migration and feeding area

Conservation targets and conservation objectives

The conservation targets and conservation objectives for the Kadet Trench NCA result from §3 of the Protected Area Ordinance (NSGKdrV). They include, in particular, the maintenance and restoration of:

  • The specific ecological functions, biodiversity and natural hydro- and morphodynamics of the area
  • The undisturbed exchange of water from North Sea and Baltic Sea as well as the connection and stepping-stone function for the ecosystems of the western and central Baltic Sea
  • A favourable conservation status of the habitat type "reefs" (Code 1170) with the characteristic and endangered ecological communities and species
  • A favourable conservation status of the HD species harbour porpoise and its habitats (e.g. through ASCOBANS Recovery Plan for Harbour Porpoises in the Baltic Sea).

Main anthropogenic uses in the Kadet Trench NCA

There is intensive shipping traffic in the Kadet Trench NCA. A traffic separation scheme extends over approximately the whole width of the protected area (about 90% of the area). The mean density of shipping traffic is between 30 and 40 ships per km² and day (predominantly cargo ships, but also ferries). The high densities of shipping traffic have negative effects, especially on the harbour porpoises which react very sensitively to underwater noise. Seabirds that are sensitive to disturbances, e.g. divers or various sea ducks, avoid such strongly frequented areas, although they would find much food here.

Shipping traffic regulations can only be agreed at an international level by the International Maritime Organisation (IMO). Possible protection measures could be, for example, a reduction in the noise from ships through the deployment of quieter ship propulsion systems or temporally or spatially regulated speed limits.

Recreational fishing could be regulated

Recreational fishing regulations were implemented when the Protected Area Ordinances came into effect. In the central part of the NCA, there is thus an area of about 30 km² that is closed to recreational fishing from 1 February to 31 May. Another slightly larger area of about 40 km² is closed all year. The important and ecologically especially valuable reef areas of the NCA, for example, are located in the regulatory zones.

Commercial fishing regulations can only be issued within the framework of the EU's Common Fisheries Policy (CFP). The proposed measures are currently going through complicated national and European agreement processes.

Multiple different ship types use the Kadet Trench traffic separation scheme. The mean density of shipping traffic is up to 40 ships per km² and day.
Multiple different ship types use the Kadet Trench traffic separation scheme. The mean density of shipping traffic is up to 40 ships per km² and day.

Selected maps (German)

Selected publication (German)

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