Chris Andra 0608H
Cruise summary report
|Ship name (ship code)||Chris Andra (74TZ)|
|Cruise period||2008-06-27 — 2008-07-16|
|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 the north western North Sea and 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 26 June and loaded onto the vessel. Scientific equipment was installed and tested by 2000hrs on 26 June. The vessel departed at 0830hrs on Friday 27 June and made passage to Loch Eriboll where all three frequencies of the EK60 sounder were calibrated, finishing at 1000hrs on the 28 June.
The survey started on the morning of 28 June, after a trial trawl to familiarize the crew with the fishing gear, and proceeded south through the Minch following the cruise track. Acoustic data was gathered at 38, 120 and 200 kHz from the times between 0300 and 2300 hours.
On the morning of 7 July, passage was made to Loch Broom where a second calibration of the acoustic equipment was performed. This was completed at 1130hrs, at which point the vessel sailed to Ullapool to allow for a change of crew, the replenishment of supplies and to provide a rest day in compliance with WTD requirements.
The vessel departed at 1200hrs on the 8 July and sailed to the Butt of Lewis to complete the northern part of the survey area, finishing at 1200hrs on 15 July and returning to Fraserburgh on the morning of 16 July for unloading. 22,763 MB of acoustic data at 3 frequencies was recorded.
24 pelagic trawls were conducted to identify significant echo traces, with 15 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 16 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)|
|Project||International North Sea Herring Acoustic Survey|
|Cruise report||(0.43 MB)|
Inner Seas off the West Coast of Scotland
North East Atlantic Ocean (limit 40W)
|Specific||Northwestern North Sea and West of Scotland|
|Track charts||(00 MB)|