Walther Herwig III, 341st cruise

Duration
2011, January 20th - February 18th

Area
North Sea

Cruise purpose
International Bottom Trawl Survey (IBTS)

Annually in every first quarter of the year since 1966, the North Sea states estimate the strength of the juvenile stocks of the most economically valuable commercial fish in the North Sea. Under the coordination of the International Council for the Exploration of the Seas (ICES) seven research ships carry out largely simultaneous standardized ground trawl net catches on adult and juvenile fish which serve as the basis for the determination of populations. Additional plankton net catches give information on the extent and distribution of herring and sprat larvae since 1999. Also, the measurements of the environmental parameters temperatures, salt content and nutrients in all water levels belong to the standard program at each fishery station.

The fisheries research vessel “Walther Herwig III” fills in the German part of this survey.

After standardized preparation, the model calculation data provides insight into the newest population developments. On this basis the EU fishery ministers determine the total permissible catch quantities of commercial fish in the North Sea.

Scientist in charge
Dr. Gerd Wegner, Institute of Sea Fisheries