RV Cefas Endeavour 18/07
Cruise summary report
|Ship name (ship code)||RV Cefas Endeavour (74E9)|
|Cruise period||2007-09-27 — 2007-10-04|
|Port of departure||Lowestoft, United Kingdom|
|Port of return||Lowestoft, United Kingdom|
1. To conduct a standard underwater TV survey of Nephrops burrow densities on the Farn Deeps grounds, 55° 35' - 54° 45' N and 1° 30' - 0° 40' W, and to evaluate Nephrops abundance for comparison with previous years.
2. To collect concurrent video data, using a second camera, which will be directly comparable with that collected from other Nephrops grounds.
3. To characterise sediment features at and between TV survey stations using a remote acoustic seabed discrimination system (swathe bathymetry and QTC).
4. To trial the deployment of a lander for the remote collection of static video observations and environmental data.
CEFAS ENDEAVOUR sailed from Lowestoft at around high tide at 09:00h local time on 27 September.
Gales in the Northern North Sea made for an uncomfortable passage up to the Farn Deeps. We arrived at the southerly end of the grid at about 03:00h 28 September. Because of the North Easterly gale force winds and swell, we continued to the north of the survey area and waited until daylight. The first station was carried out at 07:30h. Although the swell, wind and strong spring tides affected the quality of the first few tows, these tows allowed the sledge and camera setup up to be tuned for the rest of the survey.
The weather improved slowly as we worked round the clock picking our way from one station to another zigzagging southward down the survey grid. However, at 22:00h we lost the picture from the sledge, the sledge was retrieved and work stopped. The fault was traced to the cable and a loose connection on the winch slip rings. It was apparent that the cable would fail eventually but it would take 24hrs to repair. It was still usable, so despite the fault, it was re-rigged and the survey recommenced at 03:30h 29 September. While the survey carried on, the spare cable and the side winch were prepared for the original cables eventual demise. At 18:45h it did fail, the cables were changed over, and the
|Chief scientist||Jonathon Mark Elson (Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory)|
|Cruise programme||(0.03 MB)|
|Cruise report||(0.09 MB)|
|Track charts||(0.08 MB)|