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FRV Alba Na Mara 0820A

Cruise plan

Cruise Info. 
Ship name (ship code)FRV Alba Na Mara (74NM)
Cruise identifier0820A
Cruise period2020-11-27 — 2020-12-18
StatusCompleted
Port of departureFraserburgh, United Kingdom
Port of returnFraserburgh, United Kingdom
PurposeResearch
ObjectivesObjectives

1. To determine the abundance, length and age of sandeels in the sediment from regions east of the Firth of Forth and around Turbot bank.
2. To collect and preserve samples of A. marinus, 30-50 fish from each of two sites (Wee Bankie, Turbot Bank) for further genetic analyses.
3. To determine the sex and maturity stage of all sandeels selected for ageing.

Procedure

All required gear will be loaded onto the vessel on 24 November. The SIC will join the vessel in Fraserburgh on 27 November.

Two regions of historical importance for sandeel fishing will be surveyed. In the period 27 November - 2 December, weather permitting, Northern stations and possibly West Turbot Bank stations will be sampled. A modified scallop dredge will be used to catch sandeels buried in the substrate at the priority stations given in Table 1 and Figure 2. Further stations in this region will be sampled if time permits. After the crew change, on December 6, Alba Na Mara will be heading south to Montrose harbour as this period (6th and the following days) is favourable (high tides: 6.33 am/6.42pm on the 7th) to get in and out of the harbour at times compatible with a 7am-7pm working day. Southern stations (stations 3,4, 7-10,12 and 19) will be sampled. Including steam time, a 12 hour shift would allow the sampling of a station each day. Once the southern stations have been sampled, Alba Na Mara will head back to Fraserburgh harbour and resume the sampling of Northern stations.

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. In addition if time and weather allows, new stations will be considered in the Moray Firth.

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 (objective 1). All 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 (objective 2). Sandeels selected for ageing will be hand stripped and assigned a maturity stage based on a simple three-point scale (I = immature/indeterminate sex; MM= mature male; MF = mature female). Immature individuals will be individually frozen for further dissection and assigned to 1 of 2 stages (IM =Immature male or IF= Immature Female) (objective 3).

All operations on board will be performed in compliance with the required regulations and guidance associated with the Covid-19 pandemic. Following the completion of survey work, Alba na Mara will return to Fraserburgh for unloading.
Chief scientistThomas Regnier (Marine Scotland Aberdeen Marine Laboratory)
Cruise programmeFRV Alba Na Mara 0820A cruise programme 0820a.pdf  (0.45 MB) 
Ocean/sea areas 
GeneralNorth Sea
SpecificWee Bankie, Turbot Bank