Winter residency and site association in the critically endangered North East Atlantic spurdog (Squalus acanthias)

• Published in: Marine Ecology Progress Series
• Main Authors: Thorburn, J., Neat, F., Bailey, D.M., Noble, L.R., Jones, C.S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-Research 2015
• Subjects: North East Atlantic; Squalus acanthias
• Online Access: https://eprints.gla.ac.uk/102466/; https://eprints.gla.ac.uk/102466/1/102466.pdf

Identification and incorporation of residential behaviour into elasmobranch management plans has the potential to substantially increase their effectiveness by identifying sites where Marine Protected Areas (MPAs) might be used to help conserve species with high migratory potential. There is evidence that spurdog (Squalus acanthias) displays site association in some parts of its global distribution, but this has currently not been shown within the North East Atlantic where it is critically endangered. Here we investigate the movements of electronically tagged spurdog within Loch Etive, a sea loch on the west coast of Scotland. Archival data storage tags (DSTs), that recorded depth and temperature, revealed that mature female spurdog over wintered within the loch, restricting their movements to the upper basin, and remaining either in the loch or the local vicinity for the rest of the year. This finding was supported by evidence for limited movements from conventional mark/recapture data and acoustically tagged individual spurdog. Some of the movements between the loch basins appear to be associated with breeding and parturition events. This high level of site association suggests that spatial protection of the loch would aid the conservation of different age and sex classes of spurdog.