RV Cefas Endeavour 12/23
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RV Cefas Endeavour (74E9) |
| Cruise identifier | 12/23 |
| Cruise period | 2023-08-07 — 2023-09-03 |
| Status | Completed |
| Port of departure | Lowestoft, United Kingdom |
| Port of return | Lowestoft, United Kingdom |
| Purpose | Research |
| Objectives | Primary Aims
1. To carry out a groundfish survey of the North Sea as part of the ICES coordinated IBTS, using a hybrid GOV trawl in order to obtain information on: a) Distribution, size composition and abundance of all fish species caught. b) Age – length distribution of selected species. c) Distribution of fish in relation to their environment. d) Distribution of macrobenthos and anthropogenic debris. e) Surface and bottom temperature and salinity data using ESM2 profiler/mini-CTD logger and Niskin Bottle. f) Length weight & maturity information using individual fish measurements, in support of the EU Data Regulation. Secondary Aims 2. Tag and release specimens of starry smooth-hound Mustelus asterias, spurdog Squalus acanthias, tope Galeorhinus galeus, common skate Dipturus batis species-complex, blonde ray Raja brachyura and cuckoo ray Leucoraja naevus, in support of the ICES Working Group for Elasmobranch Fishes work to inform on stock units for demersal elasmobranchs. 3. To freeze any unusual fish species for subsequent identification / verification in the laboratory, including specimens of eelpout (Zoarces, Lycodes and Lycenchelys), sea scorpions (Cottidae, sub-area IVa only), and any unusual fish species, which may also be used in otolith research. 4. To retain any dead specimens of tope (Galeorhinus galeus) and common skate (Dipturus batis species-complex) for biological studies. 5. Retain any dead specimens of shad and lamprey for biological studies. 6. Collect fisheries acoustic continuously data at five operating frequencies (38, 70, 120, 200 and 333kHz), using the Simrad EK80 split beam sounder. The data will contribute to the existing time series of acoustic data in the North Sea and will be used as part of a study monitoring changes in mackerel distribution and abundance. 7. Cetacean observations will be recorded where possible and sent to the Sea Watch Foundation. 8. Identification, count, measure and weigh all jellyfish caught in GOV trawl will allow the continuation of the North Sea August Jellyfish dataset started in 2012; As the dataset grows from year to year, this should allow the evaluation of changes in jellyfish community and biomass with time. 9. Collect squid egg samples to map spawning grounds. This could be highly relevant in studying squid stock structure. Retain any specimens of Loligo vulgaris (not L. forbesi – keep all if in doubt) and all ommastrephidae squids (Illex, Todaropsis, Todarodes) for maturity and age analysis, respectively. 25 Alloteuthis are to be retained for maturity and age analysis. 10. Collect, retain and filter surface water samples from Ferrybox underway water supply every 12 hours (or once a day) for subsequent chlorophyll sampling in support of SLA25. 11. Zooplankton plankton sampling using ring net to collect sample from the Gabbard smart buoy site. 12. Collect queen scallops (queenies) Aequipecten opercularis to allow for experimental work on ageing, for L/W relationship analysis, development of length to height parameters and, to provide specimens to Bangor University for further work which will be made available to ICES WGScallop. 13. To collect specimens of Alloteuthis sp. with associated photography for identification studies into the potential increase of A. media in UK waters. 14. Collect additional data from dead skates and rays (males: testes weight and outer clasper length; females: ovary weight and shell gland width) and collect a section of vertebral column comprising ca. 6-8 vertebrae from that part overlying the body cavity; samples to be kept frozen - as part of Defra project C8503. 15. Genomic sampling of particular fish species to improve the methodology to assess finfish, |
| Chief scientist | Richard Humphreys (Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory) |
| Cruise report |  (4.21 MB) |
| Ocean/sea areas | |
| General | North Sea |
| Specific | North Sea (ICES divisions 27.4a, b and c) |
