FFS Walther Herwig III 455
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FFS Walther Herwig III (06NI) |
| Cruise identifier | 455 |
| Cruise period | 2022-03-30 — 2022-04-25 |
| Status | Completed |
| Port of departure | Bremerhaven, Germany |
| Port of return | Bremerhaven, Germany |
| Purpose | Research |
| Objectives | The mackerel and horse mackerel egg survey forms a part of an ICES-coordinated international study in the Eastern North Atlantic conducted during the first half of 2022. This investigation takes place triennially since the late 1970s and is coordinated by the ICES Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS).
The main objective of this series of individual cruises from January until August is to produce both an index and a direct estimate of the biomass of the Northeast-Atlantic mackerel stock and the southern and western horse mackerel stocks. The mackerel and horse mackerel egg survey is the main source providing fishery independent information for these stocks. The general method is to quantify the freshly spawned eggs in the water column on the spawning grounds. To be able to establish a relationship between eggs and spawning stock biomass, the fecundity of the females must also be determined. This is done by sampling sufficient numbers of gonads before, during and after spawning. These samples are then histologically analysed. In combination, the realised fecundity (potential fecundity minus atresia) of the females and the actual number of freshly spawned eggs in the water render an estimate of the spawning stock biomass. As a consequence of the long spawning period and the large area involved – for the first time in 2022 including the North Sea in the same year-, the mackerel and horse mackerel eggs surveys have been highly international from the very beginning. In 2022 a total of 18 individual cruises with research vessels and chartered fishing vessels will be carried out, with the contribution of UK (Scotland and England), Denmark, Spain, Ireland, Portugal, Germany, the Netherlands, Faroese Islands and Norway. The cruise of FRV Walther Herwig III is a contribution to these international efforts assessing and managing the mackerel and horse mackerel stocks. Due to the pandemic (positive PCR tests) the start of the survey was delayed by 9 days. The survey itself is part of the European data sampling directive established in 2002 and financially supported by the EU. |
| Chief scientist | Jens Ulleweit (Thünen Institute of Sea Fisheries, Bremerhaven) |
| Cruise report |  (1.31 MB) |
| Ocean/sea areas | |
| General | Celtic Sea North East Atlantic Ocean (limit 40W) |
| Specific | West of UK and Ireland |
