FFS Walther Herwig III 433
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FFS Walther Herwig III (06NI) |
| Cruise identifier | 433 |
| Cruise period | 2020-01-06 — 2020-01-13 |
| Status | Completed |
| Port of departure | Bremerhaven, Germany |
| Port of return | Bremerhaven, Germany |
| Purpose | Research |
| Objectives | The 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 scientist | Nobert Rohlf (Thünen Institute of Sea Fisheries, Bremerhaven) |
| Project | ICES International Herring Larvae Survey |
| Coordinating body | International Council for the Exploration of the Sea (ICES) |
| Cruise report |  (1.65 MB) |
| NPRC | (0.34 MB) |
| Ocean/sea areas | |
| General | English Channel North Sea |
| Specific | Eastern English Channel and southern North Sea |
| Track charts | (0.14 MB) |
| Measurements | |
| Physical oceanography | |
| CTD stations | Quantity: number of profiles = 65 Description: Towed CTD |
| CTD stations | Quantity: number of profiles = 2 Description: CTD |
| Biology and fisheries | |
| Eggs and larvae | Quantity: number of hauls = 65 Description: Plankton and fish larvae catches |
| Zoobenthos | Quantity: number of hauls = 9 Description: 2m Beam Trawl |
