Identification

Title

2005 - 2005 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Selectivity of hake gill nets in the Southwest fishery 2005/06 - Fisheries Science Partnership

Alternative title(s)

FSP Selectivity of hake gill nets in the Southwest fishery

Abstract

To examine the catch composition and selectivity of a range of static gears for hake in the southwest fisheries. FSP Programme 8 demonstrated the selectivity characteristics of 120mm mesh gill nets used by UK hake fishermen off the south west coast of England. The experiment was carried out by comparing the catches in nets of mesh size 80, 100, 120 and 140mm deployed simultaneously at two fishing grounds. Additional 120mm nets were shot to obtain further data on size composition of hake. The work was carried out in October and November 2005, using the vessel *Carol H.*

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/625/

function: order

Unique resource identifier

code

CEFASac7ba728-2ade-49f1-860a-9cf997c41bd5

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

reference date

date type

revision

effective date

2011-03-25

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

publication

effective date

2008-06-01

Geographic location

West bounding longitude

-8

East bounding longitude

-3

North bounding latitude

52

South bounding latitude

49.5

Extent

Extent group

authority code

title

reference date

date type

revision

effective date

2010-05-18

code identifying the extent

Temporal reference

Temporal extent

Begin position

2005-10-08T00:00:00.000Z

End position

2005-11-14T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2017-02-14

Frequency of update

notPlanned

Quality and validity

Lineage

The project objectives were addressed primarily through analysis of length frequency data. The length frequencies reflect a combination of the selectivity characteristics of the gear and the abundance of fish of different sizes present at the times and locations where the gear is fished. The selectivity of the gear can be represented by a curve showing the probability of fish of different sizes being caught when they try to escape the gear. In the case of a gill net where the majority of fish become gilled or wedged in the meshes, the curve is often bell shaped, with the peak corresponding to the sizes of fish most likely to be enmeshed. If additional fish are caught by entanglement (e.g. by teeth in the case of hake), the selection curve may cover a broader range of lengths or even have more than one length mode. When estimating the shape of the hake gill net selectivity curves, the variations in abundance of fish of different sizes around the net have to be considered. For enmeshing gears such as gill nets, the normal approach is to hang fleets of nets of different mesh but otherwise identical construction, and to compare the length frequencies in each. This approach was adopted for this FSP project.

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

2017-02-14T10:26:47

Metadata language