Cruise summary report
|Ship name (ship code)||Prowess (74P3)|
|Cruise period||2007-06-30 — 2007-07-19|
|Port of departure||Fraserburgh, United Kingdom|
|Port of return||Fraserburgh, United Kingdom|
1. To conduct an acoustic survey to estimate the abundance and distribution of herring in West of Scotland (ICES area VIa(N) as part of the ICES International North Sea Herring Acoustic Survey.
2. To obtain samples of herring for biological analysis, including age, length, weight, sex, maturity and ichthyophonus infection.
All gear was transported to Fraserburgh by lorry and furniture van on 28 June and loaded onto the vessel. Scientific equipment was installed and tested by 1900 on 28 June. The vessel departed at 1800 on Friday 29 June and made passage to Loch Erribol where all three frequencies of the EK60 sounder were calibrated.
The survey was started at 0300 on the morning of 1 July and proceeded south through the Minch. Acoustic data was gathered at 38, 120 and 200kHz from the times between 0300 and 2300 hours.
On the morning of 10 July, passage was made to Loch Broom where a second calibration of the acoustic equipment was performed. This was completed at 1200, at which point the vessel sailed to Ullapool to allow for the replenishment of supplies and to provide a rest day in compliance with WTD requirements.
The vessel departed at 1300 on the 11 July and sailed to the Butt of Lewis to complete the northern part of the survey area, finishing at 1400 on 18 July and returning to Fraserburgh on the morning of 19 July for unloading.
23,655 MB of acoustic data at 3 frequencies was recorded.
A total of 30 pelagic trawls were conducted to identify significant echo traces, with 24 of these yielding more than 20 herring.
Samples of all species caught were measured for length and weight to establish a length weight relationship. Otoliths were collected from a sub-sample of the herring for later analysis to determine age. Maturity state was recorded and herring were examined for the presence of Icthyophonus infection.
The vessel returned to, and the gear was unloaded in, Fraserburgh on the morning of 19 July. The gear was returned to the laboratory by lorry and furniture van. Staff returned by minibus.
|Chief scientist||Eric Armstrong (Fisheries Research Services Aberdeen Marine Laboratory)|
|Cruise report||(0.09 MB)|
|General||Inner Seas off the West Coast of Scotland|
North East Atlantic Ocean (limit 40W)
|Specific||North and West coast of Scotland|
|Track charts||(00 MB)|
|Biology and fisheries|
|Pelagic fish||Quantity: number of hauls = 30|
Description: to obtain herring for biological analysis. Also to identify significant echo traces.
|Acoustic reflection on marine organisms.||Description: Acoustic survey to estimate the distribution and abundance of herring in West of Scotland. recorded at 38, 120 and 200kHz|