FRV Alba Na Mara 1915A
|Ship name (ship code)||FRV Alba Na Mara (74NM)|
|Cruise period||2015-12-04 — 2015-12-18|
|Port of departure||Leith, United Kingdom|
|Port of return||Fraserburgh, United Kingdom|
1. To determine the abundance, length and age of sandeels in the sediment in regions east of the Firth of Forth and around Turbot bank.
2. Conduct exploratory tows within the EIWiF Neart na Gaoithe survey box, with the aim of establishing new dredge stations over suitable sandeel habitat.
3. To collect and preserve samples of A. marinus, specifically:
i) all 0-group sandeels (size to be estimated from age/length keys of sampled catches) not required for age determination;
ii) 100 age-1 individuals from each of the northerly and southerly sub-regions; and
iii) 100 individual fish, randomly sampled across the entire size range, from each of the northerly and southerly sub-regions.
4. Collect and preserve fish samples (sandeel spp. and Gobiidae spp.) for UoA MSc student.
All required gear will be loaded onto the vessel on 1 December. Scientific staff will be transported to Leith to join the vessel on 4 December.
Two regions of historical importance for sandeel fishing will be surveyed. In the first half of the survey a series of eight dredge stations to the east of the Firth of Forth will be sampled following the protocol established in 1999. A modified scallop dredge will be used to catch sandeels buried in the substrate at the priority stations. Further stations in this region will be sampled if time permits. In the second half of the survey, the dredge will be deployed at stations 20-36 in the Turbot bank region. Ideally, five repeat tows will be conducted at each station although this may be reduced to a minimum of two if catch quantities are low or available time is limited. Dredge duration will be approximately ten minutes at a towing speed between two and three (ideally 2.5) knots.
At each dredge station, all sandeels will be identified to species level, measured, and otoliths (5, 8 or 10 depending on length strata, per half centimetre) will be taken for age determination.
Weather and time permitting, exploratory tows will be conducted within the Neart na Gaoithe survey box (see Figure 2), previously surveyed in 0915A. Dredging sites will be selected using available knowledge of the seabed characteristics within the area, including sediment GIS layers and local bottom trawl catch data. The aim is to establish dredge stations that can be monitored as part of a new ROAME examining potential ecological impacts of offshore wind developments.
0-group sandeels will be retained and frozen individually for later analysis. Sub-samples of 100 age-1 (size to be determined from age-length keys of sampled catches) A. marinus will be taken from the northerly (latitude > 57°N) and southerly (latitude < 57°N) sub-regions. Similarly, 100 sandeels from each sub-region will be randomly sampled across the size range caught by the dredge to investigate inter-annual variation in maturity (Objective 3). Additional fish samples requested by a University of Aberdeen MSc student will be taken on an ad hoc basis (Objective 4).
Following the completion of survey work, Alba na Mara will return to Fraserburgh for unloading on 18 December 2015.
|Chief scientist||Joanne Clarke (University of Glasgow Institute of Biodiversity, Animal Health and Comparative Medicine)|
|Specific||East of the Firth of Forth and around Turbot Bank.|