Identification

Title

2007 - 2008 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Thames ray tagging and survival 2007/08- Fisheries Science Partnership

Alternative title(s)

FSP Thames ray tagging and survival

Abstract

To examine, primarily through traditional tagging methods, the survival rates of rays of a range of sizes released after capture by small otter trawlers, gillnetters and linefishing vessels. Timing: April - July 2007. Includes length, sex and maturity data, as well as positional and bycatch data.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/631/

function: order

Unique resource identifier

code

CEFASea57d9e9-d200-4d1a-a957-48a8002faba8

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

0.5

East bounding longitude

2

North bounding latitude

52

South bounding latitude

51.25

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

2007-01-01T00:00:00.000Z

End position

2008-01-01T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2020-06-16

Frequency of update

notPlanned

Quality and validity

Lineage

This Fisheries Science Partnership project was developed to estimate the longer-term survivorship and movements of thornback ray Raja clavata in the southern North Sea, using traditional tagging methods. Thornback ray is the dominant skate species taken in targeted and mixed fisheries in this area, and is taken in various trawl, line and gillnet fisheries. Five inshore vessels were used in the study, with seven trips planned in order to examine the catches and survivorship following capture by small otter trawlers, gillnetters and longline vessels. A variety of skate and ray species is marketed as ‘skate’, and commercial landings data are for all species combined. The lack of species-specific landings data has hampered assessments of the status of individual stocks and species, although species-specific landings are required for the main skate species taken in the North Sea from 2008. Some of the larger-bodied skate species, such as common skate Dipturus batis are now of conservation concern. The main objectives of this study were to (1) examine the species, sex and size composition of skates (Rajidae) taken in inshore fisheries in the southern North Sea, (2) assess the survivorship of commercially caught fish and (3) undertake a tag-and-release programme for thornback ray. Owing to the size of the vessels involved in the fishery and the fishing locations, the utility of examining short-term survival using holding tanks was limited, although such studies have been undertaken on complementary studies in the Bristol Channel. A visual assessment of the health of fish caught under commercial conditions was made on board, with the majority of fish subsequently tagged with a Petersen disc and returned. Given that the trawlers and liners have short tow durations/soak times, most were in a good state of health, and these gear deployments were as used when fishing commercially. Studies with gillnets used 24 h soak times (as opposed to the commercial 30–48 h soak time, for which mortality would likely be very high), with drift trammelnets deployed for the standard 1–3 h.

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

2020-06-16T13:05:45

Metadata language