RV Corystes COR4/01

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Corystes (74RY)
Cruise identifierCOR4/01
Cruise period2001-04-26 — 2001-05-14
Port of departureLowestoft, United Kingdom
Port of returnLowestoft, United Kingdom
ObjectivesPart A
1. To evaluate performance of VEMCO sonar buoy for detecting coded acoustic tags (VEMCO) in open sea conditions. The VEMCO sonar buoy failed to log data successfully.
2. To tag cod with coded acoustic tags and deploy CEFAS 76 kHz sonar buoy to monitor their subsequent residence within the tagging location.
Part B
1. To trial an integrated EK500/QTC acoustic system for surveying the seabed and water column simultaneously.
2. To use acosutic and fishing survey methods to estimate the abundance and distribution of sandeels on sandeel fishing grounds on the western Dogger Bank.
3. To use QTC to describe sediment type in relation to sandeel distrubution and abundance.
4. To identify suitable sites (wrecks or hard ground) in the vicinity of the sandeel survey area (western Dogger Bank) where adult cod occur and can be caught and tagged.
Chief scientistJulian David Metcalfe (Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory)
Cruise reportRV Corystes COR4/01 cruise report cory4_01.pdf (0.16 MB) 
Ocean/sea areas 
GeneralNorth Sea
Track chartsRV Corystes COR4/01 cruise track — cory4_01trk.pdf (0.14 MB) 
Physical oceanography 
CTD stationsDescription: CTD casts were made at regular intervals along the survey grid.
Biology and fisheries 
PhytoplanktonDescription: Plankton samples taken at regular intervals.
ZooplanktonDescription: Plankton samples taken at regular intervals.
Demersal fishDescription: cod caught using rod and line.
TaggingsQuantity: number of specimens = 50
Description: cod tagged. Eight cod tagged with coded pingers, a further 5 cod were tagged internally and 37 cod were tagged with conventional Petersen discs.
Gear researchDescription: Evaluation of VEMCO sonar buoy.
Geology and geophysics 
DredgeQuantity: number of hauls = 6
Description: ten minute tows made using a 1.2m sandeel dredge.
Bottom photographyQuantity: number of deployments = 1
Description: trials carried out with a towed underwater camera in an attempt to visualise sandeels in the water column.
Multi-beam echosoundingQuantity: activity duration in hours = 91
Description: Acoustic survey using the Simrad EK500 dual frequency, split beam echo sounder and QTC acoustic system in an attempt to establish whether the method could detect sandeels buried in the sediment at night.