FRV Scotia 0613S
|Ship name (ship code)
|FRV Scotia (748S)
|2013-05-27 — 2013-06-15
|Port of departure
|Aberdeen, United Kingdom
|Port of return
|Aberdeen, United Kingdom
1. To obtain estimates of the abundance and distribution of Nephrops burrow complexes at Fladen, in the North Minch, the South Minch, the Firth of Clyde and at Devil's Hole. If time and weather permits, stations in the Sound of Jura may also be surveyed.
2. To use the TV footage to record the occurrence of other benthic fauna as well as evidence of commercial trawl activity.
3. To collect sediment samples at each station.
4. To carry out trawling for Nephrops, based on one haul in each sediment stratum in each of the main survey areas, to obtain samples of Nephrops for size composition analysis.
5. To collect samples of Nephrops for comparison of reproductive condition and morphometrics in each of the different survey areas (functional units).
The main areas in which the survey will take place have been surveyed on annual basis for a number of years. A combination of two approaches will be used to derive the survey positions. The majority of stations will be generated by employing the traditional stratified random technique in all areas except the North Minch, where stations will be created using commercial effort based data obtained from the Vessel Monitoring System. The location of all TV stations will be provided ahead of the survey.
Weather permitting, it is planned that the vessel will first steam to the deep water in the Southern Trench (in the East of the Moray Firth) where a training session in deploying the sledge, and approximately 450 m of cable, will be carried out. The sledge will then be recovered and when this procedure is carried out to the satisfaction of all involved, the vessel can then progress on to the first of the Nephrops burrow TV stations at the SW edge of the Fladen ground. Once the work at Fladen has been completed, the vessel will then steam around to the west coast and survey stations in the North and South Minches.
The progress of the work to this point in the cruise will determine if the vessel continues with the survey and completes all the stations in the Clyde area before heading to Belfast for the half landing, or if the vessel will head to port first and then complete the Clyde survey following the half landing.
If time and the weather permits the sound of Jura will then be surveyed followed by the remaining South and North Minch stations whilst working north. Any additional stations in Fladen (if required), or those not covered on the first leg of the survey, will be completed before heading to the final survey area at the Devils Hole.
When on station, sledge deployments and TV observations will be carried out 24 hours a day. Three teams, each comprising of two people, will each be working eight hour shifts and be involved in deploying and recovering the TV equipment, recording data and liaising with the ship's compliment. There will be a requirement for staff to review video footage at sea outwith their shift period, as well as assisting in working up trawl catches and data entry. All work will be carried out in accordance with WTD regulations. Staff teams on each shift, watch leaders and the shift patterns will be provided to the ship prior to sailing.
At each TV station a video camera mounted on to the TV sledge will be towed along the seabed for approximately ten minutes - the ship's dynamic positioning will be required for this. Observed Nephrops burrows, surfaced Nephrops and other benthic fauna will be recorded onto DVD for analysis. The depth and distance travelled by the sledge, as well as camera height from the sea bed will be recorded automatically. Where practical sediment samples will be taken using the mini van Veen grab mounted on the sledge. However, it may be necessary to use the Day Grab on occasion, if the mini van Veen fails. All sediment samples will be fro
|Adrian Weetman (Marine Scotland Aberdeen Marine Laboratory)
Inner Seas off the West Coast of Scotland
|Fladen, North Minch, South Minch, Firth of Clyde, Devil's Hole.