Variability of harbour seal (Phoca vitulina) foraging behaviour during out-migrations of salmon smolts ...

• Main Author: Allegue, Hassen
• Format: Text
• Language: English
• Published: University of British Columbia 2017
• Subjects: harbour seal; Phoca vitulina
• Online Access: https://dx.doi.org/10.14288/1.0348378; https://doi.library.ubc.ca/10.14288/1.0348378

There is increasing evidence that predation by harbour seals (Phoca vitulina) on salmon smolts out-migrating from rivers may be a significant source of mortality for coho (Oncorhynchus kisutch) and Chinook (O. tshawytscha) salmon populations in British Columbia. Studies supporting this have focused on documenting what and how much seals eat—and the potential impact this has on salmon populations. However, little attention has been given to understanding where, when and how this predation occurs, and the extent to which it might be opportunistic or specialist feeding behaviour by a few or many individuals. I documented the spatiotemporal foraging behaviour of harbour seals in the Salish Sea by equipping 17 seals with biologgers—and tracking them before and after the release of thousands of coho and Chinook smolts from the Big Qualicum Hatchery. Reconstructing the high-resolution movements of the seals―and quantifying feeding using counts of prey chasing events (PCEs) detected by accelerometry—revealed that ...