FFS Walther Herwig III 433

Cruise summary report

Cruise Info. 
Ship name (ship code)FFS Walther Herwig III (06NI)
Cruise identifier433
Cruise period2020-01-06 — 2020-01-13
Port of departureBremerhaven, Germany
Port of returnBremerhaven, Germany
ObjectivesThe cruise is part of the German contribution to the international herring larvae surveys in the North Sea (IHLS). These surveys are conducted during the autumn and winter herring spawning activity. The ICES coordinated studies monitor the spatial distribution and abundance of herring larvae on an annual basis. Survey results gives information about herring spawning stock biomass and the contribution of different spawning components on the overall hatching
success. The results provide valuable information for herring stock assessment and the fixation of fishing quotas.

The amount of herring larvae caught (12,000) is in line with preceding years (12,000-20,000 larvae, except 2017). Most herring larvae were found in the south-western part of the survey area, in front of the French coastline, and higher quantities of larvae occurred also in Belgian waters. However, conclusions for North Sea herring spawning stock dynamics can only be drawn when information of larvae abundance from all spawning areas become available prior to the herring assessment working group meeting in March 2020.

As an additional task, the winter benthos species composition in Box A was examined. Benthos samples revealed extreme low abundances of the shrimp Crangon crangon and the brittle star Ophiura ophiura, as well as the complete absence of the bivalve Nucula nitidosa. The latter was frequently found in Box A since 1998, but is absent since 2018.
Chief scientistNobert Rohlf (Thünen Institute of Sea Fisheries, Bremerhaven)
ProjectICES International Herring Larvae Survey
Coordinating bodyInternational Council for the Exploration of the Sea (ICES)
Cruise reportFFS Walther Herwig III 433 cruise report waltherherwigiii_433.pdf (1.65 MB) 
NPRCFFS Walther Herwig III 433 NPRC waltherherwigiii_433.pdf (0.34 MB) 
Ocean/sea areas 
GeneralEnglish Channel
North Sea
SpecificEastern English Channel and southern North Sea
Track chartsFFS Walther Herwig III 433 cruise track — waltherherwigiii_433trk.pdf (0.14 MB) 
Physical oceanography 
CTD stationsQuantity: number of profiles = 65
Description: Towed CTD
CTD stationsQuantity: number of profiles = 2
Description: CTD
Biology and fisheries 
Eggs and larvaeQuantity: number of hauls = 65
Description: Plankton and fish larvae catches
ZoobenthosQuantity: number of hauls = 9
Description: 2m Beam Trawl