FFS Walther Herwig III 437
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FFS Walther Herwig III (06NI) |
| Cruise identifier | 437 |
| Cruise period | 2020-07-22 — 2020-08-13 |
| Status | Completed |
| Port of departure | Bremerhaven, Germany |
| Port of return | Bremerhaven, Germany |
| Purpose | Research |
| Objectives | Survey WH 437 covered fisheries research representing the German contribution to the International Bottom Trawl Survey (IBTS) in the annual quarter 3, as well as one component of the two-ship operation in the German Small-scale Bottom Trawl Survey (GSBTS). Both surveys use the same principle fishing methods but at different spatial scales, applying a GOV otter board trawl. A large subset of the fishing hauls is accompanied by hydrographic measurements and investigations of benthic epifauna, infauna and sediments. Bycatch of marine litter in the GOV is reported.
The GSBTS is a national program to monitor small-scale variability as well as long term changes in demersal fish assemblages in relation to physical and biological habitat characteristics. In order to fully cover the international IBTS programme, the GSBTS component of the survey in the western North Sea had to be reduced due to constraints in available ship time. Upon special request to the ICES IBTS-Working Group, plankton hauls with the MIK were conducted at night-time in order to assess the distribution of clupeid fish larvae during the third quarter of the year. Additional vertical plankton hauls at selected stations supported a research project on food webs. The start of the survey was postponed due to technical problems of the vessel, leading to a delay of the departure, which was originally planned for July 16th. The survey vessel departed on 22 July 2020 from Bremerhaven, starting investigations for the IBTS on 23 July. The Walther Herwig III returned to Bremerhaven one day earlier than scheduled, on August 13, because work in the northernmost part of the survey area (Box M) had to be terminated prematurely due to a winch failure. |
| Chief scientist | Anne Sell (Thünen Institute of Sea Fisheries, Bremerhaven) |
| Project | ICES International Bottom Trawl Survey (IBTS) |
| Coordinating body | International Council for the Exploration of the Sea (ICES) |
| Cruise report |  (0.68 MB) |
| Ocean/sea areas | |
| General | North Sea |
