FRV Scotia 0612S
Cruise summary report
|Ship name (ship code)||FRV Scotia (748S)|
|Cruise period||2012-05-25 — 2012-06-13|
|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 and the Noup 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).
6. To collect samples of Nephrops stomachs for evidence of the parasite Stichocotyle nephropis).
7. To carry out environmental impact sampling in and around the Elgin gas field. This will include water samples, sediment samples and trawling using the BT175.
Following a slight delay in sailing due to thick fog at Aberdeen harbour, MRV Scotia began work in the Southern Trench on 25 May. At this first station, 550 m of the TV cable was paid out then re-spooled back on to the winch under tension to avoid loose coils of cable developing later in the survey. This also doubled as a training exercise for the ship and allowed field trials of all the equipment, which highlighted a problem with both the video camera and mini van Veen sediment grab. Both items were replaced en route to Fladen later in the day.
With ideal sea conditions work progressed well through the southerly stations in Fladen over the following two days with a trawl on the night of 27 May. The weather changed for the worse on 28 May but this did not hinder TV operations and by 29 May, the most northerly stations off Shetland were all completed. Work continued down the west side of Fladen with a trawl in the evening of 29 May and all the Fladen sites were completed by the morning of 30 May.
In idyllic conditions, MRV Scotia made way through the Pentland Firth arriving at the first North Minch station in the early evening on 30 May. Work continued down the west side of the North Minch before entering the South Minch by mid afternoon on 31 May, where a trawl was carried out later that evening. As the survey continued south towards Barra some stations had to be relocated due to creels and poor visibility on the sea bed. By the evening of 1 June all the sites on the west side of the South Minch had been completed and the vessel started working east, with a trawl later that evening. TV work continued around Eigg, Rhum and Staffa on 2 June before heading for the Clyde, steaming through the night.
On 3 June a route up the west side of Arran was selected, surveying TV sites en route before heading in to Loch Fyne, where at a site off Tarbert in very soft mud, the sledge struck an uncharted rock face. Initially the video and lights failed and as the equipment was being recovered it became obvious that the sledge had parted from the cable. With the location of the impact marked on the navigation chart, several attempts to recover the sledge using the trawl were carried out. 12 trawls were executed throughout the remainder of the day over the area where the sledge was lost. This caused a great deal of damage to the trawl, and at 2130 further attempts of recovery were suspended. Any Nephrops caught in these recovery trawls were worked up as standard, as catches on this survey are not used to quantify stocks but only to provide biological information. Throughout the day, while attempting to recover the sledge, alternative options were discussed. This resulted in the half landing date and venue being changed and arrangements for a replacement sledge to be delivered t
|Chief scientist||Adrian Weetman (Marine Scotland Aberdeen Marine Laboratory)|
|Project||RV1204 20088, RV1205 20089, 20134|
|Cruise report||(0.08 MB)|
Inner Seas off the West Coast of Scotland
|Specific||Fladen, North Minch, South Minch, Firth of Clyde, Devil’s Hole.|
|Track charts||(00 MB)|