FFS Walther Herwig III 364
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FFS Walther Herwig III (06NI) |
| Cruise identifier | 364 |
| Cruise period | 2013-03-20 — 2013-04-25 |
| Status | Completed |
| Port of departure | Bremerhaven, Germany |
| Port of return | Bremerhaven, Germany |
| Purpose | Research |
| Objectives | ICES-coordinated international study in the Eastern North Atlantic. The main objective 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 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. To provide a reliable estimate of the quantity of spawned eggs and the fecundity, an extensive coverage of the spawning area is required both in time and space. |
| Chief scientist | Jens Ulleweit (Thünen Institute of Sea Fisheries, Hamburg) |
| Project | International Mackerel and Horse Mackerel Egg Survey 2013 |
| Coordinating body | International Council for the Exploration of the Sea (ICES) |
| Cruise report |  (1.37 MB) |
| Ocean/sea areas | |
| General | Celtic Sea Bay of Biscay North East Atlantic Ocean (limit 40W) |
| Specific | West of Ireland, Celtic Sea, northern Bay of Biscay (between 53.45 N and 48.45N). |
