2010 - 2010 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Bristol Channel 100mm codend trials 2010/11 - Fisheries Science Partnership
FSP Bristol Channel 100mm codend trials
This work was carried out as part of the Fisheries Science Partnership (FSP), a Defra-funded collaborative programme of scientific research between the UK fishing industry and scientists. Local trawlermen working in the Bristol Channel in a mixed demersal fishery wanted to know whether an increase in codend mesh size would be effective in reducing the levels of discards, and whether its use would result in the loss of marketable fish.
dataset
http://data.cefas.co.uk/#/View/643/
function: order
CEFAS02fafc97-688e-4315-83bb-7503317a550f
http://www.cefas.co.uk/
eng
OGP
urn:ogc:def:crs:EPSG::4326
biota
revision
2011-03-25
publication
2008-06-01
-5
-2
52
51
revision
2010-05-18
2010-07-01T00:00:00.000Z
2010-10-31T00:00:00.000Z
publication
2017-01-23
unknown
The gear used for the trials was a pair of twin-rig box trawls with 18 m footropes, rigged on 10 and 12 inch rockhoppers. The trawls were coupled to 15 fathom split bridles which in turn were attached to a short length of sweep (~5 fathoms). A set of A1, 6 foot otterboards were used to spread the trawls. New codends were used in the trial for both the 80 mm control codends and the 100 mm test codends. Both the test and control codends were constructed of 4 mm diameter polyethylene twine and were of a standard length of 100 meshes. To keep the cut-offs at the same length, the cut off rope was placed 30 meshes from the last round on the test codend and 36 meshes from the last round on the control codend. The mesh sizes of the codends were checked with the Omega net-measuring gauge. To account for seasonal variability in the catch, the fishing trials took place over a period of four months, between July and October 2010. Four trips of 1.5–3 days each were conducted. The trials followed the vessel’s normal fishing pattern and were carried out in both daylight and darkness. Haul duration was kept at 4 h where possible, to simulate normal fishing patterns. Hauls were conducted off the North Devon coast, including Bideford Bay, West of Lundy, and in the North and South Bristol Channel. The 80 mm and 100 mm codends were fished simultaneously side-by-side on the twin-rig trawls. Cefas scientific staff measured the lengths of all the fish caught in each haul, with the catch from each codend measured separately. The crew sorted the catch as they would normally do, and the retained fraction and discard fraction were sampled separately. When catch volumes were high, a known fraction was measured (i.e. the catch was sub sampled) and raised to provide an estimate for the haul.
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
2017-01-23T14:20:25