Capture Mark Recapture Data for Scottish Elasmobranchs: 2009-2018

doi:10.15468/znol4z

Capture Mark Recapture Data for Scottish Elasmobranchs: 2009-2018

Citation

Scottish Shark Tagging Programme, The (2022). Capture Mark Recapture Data for Scottish Elasmobranchs: 2009-2018. Occurrence dataset https://doi.org/10.15468/znol4z accessed via GBIF.org on 2025-07-09.

Description

Capture mark recapture data from the Scottish Shark Tagging Programme. The datatset includes the following species: blonde ray, bull huss, common skate, small eyes ray, smoothhound, spurdog, thornback ray, tope, undulate ray, portbeagle, sandy skate, cukoo ray and spotted ray . All records were tagged in the UK, priarily on the west coast of Scotland, however recaptures may be further afield. All data has been collected by volunteer recreational sea anglers.

Purpose

All data has been collected through an established national tagging programme and registered charity called: The Scottish Shark Tagging Programme. The programme was started in order to help understand elesmobranch distribution off the west coast of scotland and aid scientific research into site fidelity, winter residency, sex ratios, mortality rates and migrations patterns. Furthermore, the data aides with our extensive outrach programmes in schools, community group and at public events.

Sampling Description

Quality Control

The dataset has been checked using NBN Record Cleaner

Method steps

Data was provided by volunteer sea anglers all using individual baited hooks and line. Bait used depended on the species being targeted. Each fish was either measured (to the nearest cm) at the side of the boat or on board if the necessary equipment is present. We do not encourage anglers to weigh fish directly, instead they use length to weight conversion curves which, while increasing welfare standards, will reduce the accuracy of weight measurement slightly. The fish is then tagged with a unique ID number and relseased unharmed back into the water. The data shown here are only those records that contained a GPS co-ordinate, a known sex and either weight or length. In addition, the dataset also contains records of any re-captures.

Taxonomic Coverages

Geographic Coverages

The data is focused primarily on the West coast of Scotland from Luce Bay in the south to the Sound of Mull. Effort is focused on good fishing locations through invaluable and accurate local knowledge but this will still introduce some bias. Anglers will avoid certain areas thought to be devoid of good numbers of target fish even if those areas had good historical numbers. The Clyde Estuary is a good example. All data is displayed here with summary 10km grid references.

Bibliographic Citations

Contacts

originator
Scottish Shark Tagging Programme, The

metadata author
Scottish Shark Tagging Programme, The

distributor
NBN Atlas
27 Old Gloucester St, Holborn
London
WC1N 3AX
London
GB
email: admin@nbnatlas.org

Amie Williams
administrative point of contact
email: amie.williams@ssacn.org