They're Out There, You Know: Sea Turtle Sightings and Strandings in Canadian Pacific Waters

Pacific sea turtle populations primarily inhabit subtropical and tropical waters, making sightings at the edge of their range in colder high-latitude regions of the Canadian Pacific particularly uncommon and even rare. This paper presents a comprehensive summary of known occurrences in British Columbia waters from 1931 to 2024, featuring demographics, spatiotemporal distribution, and pathological findings. The dataset contains 247 sea turtle records from four species including 77 previously unpublished records. Leatherback sea turtles (<i>Dermochelys coriacea</i>) were the most frequently sighted, followed by hard-shelled sea turtle species: 34 green (<i>Chelonia mydas</i> ), three loggerhead (<i>Caretta caretta</i>), the first five olive ridley reports (<i>Lepidochelys olivacea</i>), and 54 unidentified sea turtles. Leatherbacks were primarily observed free-swimming, whereas almost half of the hard-shelled sea turtles were found dead or cold-stunned. This difference may be attributed to the inability of hard-shelled sea turtles to thermoregulate in high latitude waters. Although leatherback sightings predominantly occurred July through October, hard-shelled sea turtle records were distributed widely across all months of the year. There were 16 records involving human interactions, of which 75% were attributed to entanglement in fishing gear. Given the rarity of these occurrences and the conservation status of most sea turtle populations, these records provide important insights into high-latitude habitat use and threats, informing future monitoring and recovery efforts for these at-risk species.