RV Celtic Voyager CV18017
|Ship name (ship code)||RV Celtic Voyager (45CV)|
|Cruise period||2018-06-18 — 2018-06-29|
|Port of departure||Galway, Ireland|
|Port of return||Galway, Ireland|
|Objectives||Porcupine and Aran UWTV Survey
1. To obtain 2018 quality assured estimates of Nephrops burrow densities from a randomised isometric grid of UWTV stations at 3.5 nautical mile spacing on the Aran and 6.0 nmi spacing on the Porcupine Nephrops grounds.
2. To obtain 2018 quality assured estimates of Nephrops burrow densities from other areas in the Celtic Sea if time allows approx. 140 stations.
3. To collect ancillary information from the UWTV footage collected at each station such as the occurrence of sea-pens, other macro-benthos and fish species and trawl marks on the sea bed on the Aran Ground.
4. To collect oceanographic data using a sledge mounted CTD.
5. To sample Nephrops and macro benthos using a 3 m beam trawl deployed at ~10 stations on the Smalls ground only if time allows.
6. To satisfy the requirements of the Irish National programme under the 'Data collection regulation' EC Regulation 1543/2000.
The sled will be towed by a load bearing umbilical cable and associated winches.
RV Celtic Voyager will making between 2-3 knots for shooting into the weather. Once in the water the camera lights are switched on and warp paid out until the seabed comes into view. Shortly before touch down the vessel is slowed back to 0.8-1.0 knots. A warp-depth ratio of around between 1.4:1 and 1.8:1 is used at most stations. Once stable on the bottom the sledge is towed between 0.8-1.0 knots for around 10-14 minutes. During this time the sledge travels between 160-200m along the sea bed.
The sledge will be deployed at around 4-6 nautical mile intervals in regularly spaced grid over the survey area. The starting point for this grid will be randomized. The depth range will be from 50-147 meters (average ~100 m) for the Celtic Sea.
If time allows when TV operations are completed successfully, 10 stations selected randomly on the Smalls ground only will be trawled using beam trawl for 30 minutes using a warp-depth ratio of 3:1.
|Chief scientist||Colm Lordan (Marine Institute Galway)|