2006 - 2006 Centre for Environment, Fisheries & Aquaculture Science (Cefas) North East coast squid fishery 2006/07 - Fisheries Science Partnership
FSP North East coast squid fishery
FSP 2006/07 Programme 20, a trawl and jigging survey of squid off the North East coast of England. The survey, on board the chartered vessel FV Nimrod, was planned to take place during the fourth quarter of 2006 to coincide with the period when squid were being caught in commercially viable quantities in the area. A first trip took place from 14 to 20 December 2006 (Part 1) but found very few squid, suggesting that squid had already moved away from the fishing grounds. The second trip took place from 11 to 17 October 2007 (Part 2). That survey was one of two surveys which aimed at developing jigging as an alternative low-impact method to catch squid with little by-catch. The second survey took place off the Western English Channel and is reported separately.
dataset
http://data.cefas.co.uk/#/View/628/
function: order
CEFAS17f4fb4a-1c4e-4bd9-8784-97f48a06749b
http://www.cefas.co.uk/
eng
OGP
urn:ogc:def:crs:EPSG::4326
biota
revision
2011-03-25
publication
2008-06-01
-2
-0.5
55.75
54.5
revision
2010-05-18
2006-10-11T00:00:00.000Z
2006-12-20T00:00:00.000Z
publication
2016-11-14
011
The FV Nimrod is a 15.5 m registered length fishing trawler. The vessel carried twotrawls for the survey owing to the likelihood of gear damage. Trawl 1 was a two-panelhigh lift trawl with cut away lower wings. Trawl 2 was a three-panel high lift trawlalso with cut away lower wings. Both nets were rigged on approximately 18 m of 14 inch “ Rockhopper” ground gear. Codends of 40 mm mesh, 2 mm diameter were used on both trawls for most of the survey, but a smaller mesh cod end used in a previous FSP was deployed on trawl 2 for some of the hauls. Split bridles of approximately 45 m were deployed with 9 m of “sweeps”. Warp lengths varied with water depth. Both nets had headline heights checked using the vessel’s trawl sensor system. Trawl 1 achieved 4.8 m-headline height while Trawl 2 achieved 4.3 m. The gear was spread using a pair of Bison No 8 Otter boards. It was intended that tow duration should not exceed 1h but the type of ground being surveyed and the concentrations of static gear in the areas made this sometimes impossible. Metal halide lights, 4000 W independently generated and the vessel’s four 400 W metal halide gantry mounted lights gave a total of 5600 W. It was originally intended to position the independent lighting set aft of the wheelhouse/galley, but this proved impossible. The generator/ lights were instead positioned on top of the vessel’s shelter deck on the starboard side. South African and Japanese squid jigs of various types including plastic coated, fabric covered, weighted fluorescent and bait sticks were made. Light sticks were also deployed on the lines at certain time of the survey. The jigs were first rigged as learned during a training trip to South Africa. They are deployed in a paternoster style with typically two jigs to a line fitted approximately 1 m apart on 40 lb traces with 50 lb mainline and a 20 lb “rotten bottom”. The reason for the rotten bottom was that if the rig became entangled in the seabed, theoretically only the lead weight would be lost. After consultation with a former colleague who is at present catching L. forbesi successfully off South West England it was decided to rig some of the lines in the way they do it there (1 jig on a 4 m flowing trace attached to a “French boom”). Line colour was also changed to clear “amnesia” (Trade brand name). Weight for the rigs varied according to tidal conditions from 175 g to 400 g. A variety of storage/hauling equipment was used including rods, handlines and manually operated reels known as “gurdies”. During tidal conditions, an old trawl door was used as a drogue. Grapnel style anchors were attached to a 30 m chain, which was coupled to the vessel’s main warp. The survey was designed to cover the North East coast, inshore of the Farn Deep, in ICES rectangles 39 E8 and 38 E8 (approximately between latitudes 54o 50’N and 55o 35’N, to the west of 1oW). Trawling was conducted in a way that sampled across the entire area of the fishing grounds of interest and within the agreed limits. The initial design involved a total of 7 days trawl surveying on local rough ground followed by 7 days to evaluate jigging as a fishing method. The 7-day jigging study was to be carried out separately and subsequent to the trawl survey. Standard methods employed by Cefas staff for sorting and recording catches on commercial fishing vessels were employed (see FSP reports for details). For each species retained for landing, the total volume of the catch (number of baskets) was recorded, and a length frequency was recorded for all or a sample of the fish. All species, whether retained or discarded, were measured at each haul. For the purpose of this report, the retained and discarded components were combined for the analysis. Where catches were sampled rather than fully sorted, an appropriate raising factor was determined to allow the total catch to be estimated. FV Nimrod was equipped with a catch reception hopper and sorting table allowing random selection of samples and good detection of minority species, which could be easily separated. Owing to the relatively short tow durations and sometimes large hauls of whitefish by-catch, it was, in most cases necessary to subsample parts of the retained and discarded components. Catch rates of squid were low, so the entire squid catch was sampled and frozen for analysis at a later date. Catch rates were calculated as numbers per hour towed to standardise for the effects on catch of variable tow times.
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
originator
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
custodian
Data Manager
Centre for Environment, Fisheries & Aquaculture Science
Cefas Lowestoft Laboratory
Pakefield Road
Lowestoft
NR33 0HT
UK
+44 (0)1502 562244
pointOfContact
2016-11-14T16:54:47