In-Water Photo Identification, Site Fidelity, and Seasonal Presence of Harbor Seals ( Phoca vitulina richardii ) in Burrows Pass, Fidalgo Island, Washington

• Published in: Oceans
• Main Authors: Ciera J. Edison, Cindy R. Elliser, Katrina H. White
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2024
• Subjects: harbor seal; Phoca vitulina; Phoca vitulina richardii; Washington; Salish Sea; seasonality; Oceanography; GC1-1581
• Online Access: https://doi.org/10.3390/oceans5020022; https://doaj.org/article/1251eb4119ab4469bea410744e8db329

Little is known about the in-water behavior and site fidelity of harbor seals ( Phoca vitulina richardii ), as most photo-identification (photo-ID) studies are typically conducted while they are hauled-out on land. We investigated in-water site fidelity rates and seasonal presence in Burrows Pass, Washington, using photographs collected during a long-term photo-ID and behavioral study from January 2015 through November 2019. There was a minimum of 161 individuals and a maximum of 286 individual harbor seals using Burrows Pass. Harbor seals were present in all seasons, with the lowest sighting rates during summer. Individuals were more likely to be sighted/re-sighted in fall and spring. There was large variations in the level and seasonality of site fidelity among individuals. The majority of seals (69.62%) were seen only once, but 22.69% showed low to moderate site fidelity (2–5 sightings) and 7.69% showed strong site fidelity (≥6 sightings) over seasons and across years. These seasonal variations were likely due to foraging, life history, and individual behavioral variabilities. Studies like this provide necessary information about harbor seal in-water site fidelity and behavior, which are less well known but vitally important in harbor seal management and conservation.