FFS Walther Herwig III 464
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FFS Walther Herwig III (06NI) |
| Cruise identifier | 464 |
| Cruise period | 2023-01-27 — 2023-02-16 |
| Status | Completed |
| Port of departure | Bremerhaven, Germany |
| Port of return | Bremerhaven, Germany |
| Purpose | Research |
| Objectives | The cruise was part of the International Bottom Trawl Survey (IBTS), an internationally coordinated ICES program aiming to provide fish population data and biological parameters of commercial fish species for stock assessment purposes. Sampling of fish was conducted by trawl hauls in allocated ICES statistical rectangles by means of the ICES standard bottom trawl GOV. In total, 22 GOV hauls were taken during the cruise (67 planned hauls) accompanied by 22 CTD profiles. Standardized total catches of the GOV hauls were on average about 485 kg/30min. Highest pre-recruit number were found for herring <20cm (256685 ind./hr.) and lowest for cod <25cm (16 ind./hr.). In addition, 80 MIK plankton samples were taken (134 planned hauls) providing abundance estimates for large herring larvae (0-ringers) of the autumn spawning stock components. Standard length (SL) of herring larvae from the night time MIK sampling varied between 12- and 34mm (German data). In total, abundance of large herring larvae in the potential nurseries was lower than last year. The index from the 2023 survey (corresponding to the 2022 year-class) is 90.8 and is a bit below the long-term average of 100.7. Additional work was done on stomach collection (63 samples), cod liver worms (53 samples), had-dock gill parasites (1006 samples) and starry smooth hound genetics (25 samples). |
| Chief scientist | Hermann Neumann (Thünen Institute of Sea Fisheries, Bremerhaven) |
| Cruise report |  (1.08 MB) |
| Ocean/sea areas | |
| General | North Sea |
| Specific | Central North Sea |
| Track charts | (0.74 MB) |
