Identification

Title

2010 - 2010 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Bristol Channel 100mm codend trials 2010/11 - Fisheries Science Partnership

Alternative title(s)

FSP Bristol Channel 100mm codend trials

Abstract

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.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/643/

function: order

Unique resource identifier

code

CEFAS02fafc97-688e-4315-83bb-7503317a550f

codeSpace

http://www.cefas.co.uk/

Dataset language

eng

Spatial reference system

authority code

OGP

code identifying the spatial reference system

urn:ogc:def:crs:EPSG::4326

Classification of spatial data and services

Topic category

biota

Keywords

Keyword set

keyword value

Keyword set

keyword value

originating controlled vocabulary

title

SeaDataNet P021 parameter discovery vocabulary

reference date

date type

revision

effective date

2011-03-25

Keyword set

keyword value

originating controlled vocabulary

title

GEMET - INSPIRE themes, version 1.0

reference date

date type

publication

effective date

2008-06-01

Geographic location

West bounding longitude

-5

East bounding longitude

-2

North bounding latitude

52

South bounding latitude

51

Extent

Extent group

authority code

title

SeaVoX Vertical Co-ordinate Coverages

reference date

date type

revision

effective date

2010-05-18

code identifying the extent

Temporal reference

Temporal extent

Begin position

2010-07-01T00:00:00.000Z

End position

2010-10-31T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2017-01-23

Frequency of update

unknown

Quality and validity

Lineage

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.

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Constraint set

Limitations on public access

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Responsible organisations

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

originator

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

custodian

Metadata on metadata

Metadata point of contact

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

pointOfContact

Metadata date

2017-01-23T14:20:25

Metadata language

eng