FRV Scotia 1502S

Cruise summary report

Cruise Info. 
Ship name (ship code)FRV Scotia (748S)
Cruise identifier1502S
Cruise period2002-10-10 — 2002-10-25
Port of departureAberdeen, United Kingdom
Port of returnAberdeen, United Kingdom
Objectives1. To conduct an acoustic survey to estimate the abundance and distribution of mackerel in the northern North Sea (ICES division IVa).
2. To obtain samples of mackerel for biological analysis, including age, length, weight, sex, maturity and ichthyophonus infection.

The vessel departed Aberdeen at 15:40 and proceeded to Loch Eriboll where calibration of the four transducers was thwarted by high winds. The survey commenced in poor weather, north of the Minch, at 20:22 on 11 October. Zig-zag transects at various spacings were adopted crossing the continental slope, progressing towards the north of Shetland. Severe winds hampered progression and the transect design was altered as a result. On reaching the northerly limit of the survey area, the weather improved and transects progressed southward along lines of latitude, at spacings of 30 or 15 nautical miles (n.mi.) as planned. On 16 October, the vessel met the Norwegian FRV G.O.Sars as planned to carry out an interlaced design and an intercalibration. On completion, FRV Scotia surveyed the UK area, east of Shetland. On 21 October the echosounders were successfully calibrated south of Fetla. Storm force winds caused the vessel to suspend the survey on 22 October to seek shelter. The survey resumed on 23 October and was completed on 24 October, returning to Aberdeen the following day.
Chief scientistPaul G Fernandes (Fisheries Research Services Aberdeen Marine Laboratory)
ProjectInternational North Sea Mackerel acoustic survey
Coordinating bodyICES
Cruise reportFRV Scotia 1502S cruise report sc15_02.pdf (0.10 MB) 
Ocean/sea areas 
GeneralNorth Sea
North East Atlantic Ocean (limit 40W)
SpecificNorth of Scotland, Shetland and northern North Sea
Biology and fisheries 
Pelagic fishQuantity: number of hauls = 16
Description: Trawl samples. Measurements of fish length, weight, sex, maturity, age and species composition from catches of a PT160 pelagic trawl with a 20 mm cod end.
Pelagic fishQuantity: number of stations = 4
Description: Rod, hook & line samples. Measurements of fish length, weight, sex, maturity, age and species composition from catches of using rod, lines and feathered hooks.
Acoustic reflection on marine organisms.Quantity: track kilometres = 3945
Description: Nautical miles of track. Acoustic backscatter (MVBS and power) from 18, 38, 120 and 200 kHz, and single echo target strength from 38 kHz, 120 kHz from almost entire water column (transducers mounted in drop keel at depth of 8 m) using an EK500 scientific echosounder; continuous at rate of 1 transmission per second, over 24 hours.