Duration of the cruise: 5 to 16 Mai 2025

Cruise area: North Sea (Sylt Outer Reef and Amrumbank)

Purpose of the cruise: EEZ-Survey Northsea

The 489th voyage of the Walther Herwig is part of 

1. the national pilot project of the German Marine Research Alliance (DAM): "Exclusion of mobile bottom-touching fisheries in marine protected areas of the German EEZ of the North Sea - status description of sediment structures, benthic-pelagic habitats and biocoenoses (MGF-North Sea)" and
2. a project of the European Maritime, Fisheries and Aquaculture Fund (EMFAF): "Monitoring and assessment of benthic species and habitats in the German EEZ (MOBEEZ)“

The main focus is to systematically record the demersal fish fauna (fish that live on or near the bottom of the water) and the epibenthic fauna (organisms that live on the surface of the water bed) in the Sylt Outer Reef area using both conventional and alternative monitoring methods.

In addition to a 3-metre beam trawl for sampling the demersal fish and epibenthic fauna, a video sled will be used to record epibenthic organisms. The 3-metre beam trawl will only be used in areas from which mobile, bottom-touching fishing is not excluded.

Parallel to selected fishing hauls, water samples are to be taken along the planned tows, which are to be analysed for environmental DNA in order to investigate the possibilities of this innovative method of species detection for monitoring purposes.

Grab and box grab samples are to be taken in a dense network of stations to determine the grain size of the sediment and to determine the infauna (= animal organisms living in the sediment).