Cruise inventory

FRV Alba Na Mara 1110A

Cruise plan

Cruise Info. 
Ship name (ship code)FRV Alba Na Mara (74NM)
Cruise identifier1110A
Cruise period2010-08-19 — 2010-09-02
StatusCompleted
Port of departureFraserburgh, United Kingdom
Port of returnFraserburgh, United Kingdom
PurposeFisheries
ObjectivesObjectives

1. To obtain estimates of the distribution and abundance of Nephrops in the Firth of Forth, Moray Firth and off Arbroath using underwater cameras.
2. To use the TV footage to record occurrence of other benthic fauna and evidence of commercial trawling activity.
3. To collect trawl caught samples of Nephrops for comparison of reproductive condition and morphometrics in each of the different survey areas.
4. To collect sediment samples at each station.


Procedure

Where possible, a random stratified approach will be adopted to investigate Nephrops density in different regions of the study areas. A list of proposed stations for the survey will be made available to the ship's complement prior to the cruise.

1. TV Observations: At each station, a video camera mounted on a sledge will be towed across the seabed for approximately 10 minutes. Nephrops burrows abundance, other benthic fauna and signs of anthropogenic activity will be recorded on to DVD. Distance traveled by the sledge, the sledge depth at and camera height from the seabed will be monitored and recorded. Samples of the sediment will be taken at each station using the sledge-mounted mini Van Veen sediment grab. If this system fails at any time, the traditional winch operated Day Grab will be deployed. All sediment samples will be frozen.

2. Trawling: Fishing trawls of approximately 30 minutes duration will be made on each sediment type within each survey area. A range of biological data will be collected on Nephrops and other shellfish.

3. Drop Frame: The drop frame will be used where conditions are not suitable for using the TV sledge, recording similar data as to the TV sledge.

General

TV work will normally take place during daylight hours. There will be a requirement for some trawling to take place in the evening. On days where trawling will take place, work patterns will be arranged so not to exceed WTD recommendations. It is proposed that work will commence in the Firth of Forth.
Chief scientistJohn B Tait (Marine Scotland Aberdeen Marine Laboratory)
Ocean/sea areas 
GeneralNorth Sea
SpecificFirth of Forth, Moray Firth, North Sea off Arbroath