Rare sea turtle sighting a first for B.C.
As someone who spends approximately 60 days a year working at sea in remote locations, independent biologist Luke Halpin has more opportunity to see rare marine wildlife than most British Columbians. His findings include some species never before documented in the province like the dovekie (a small seabird) he recorded in 2013. Last month, Luke made another exceptional sighting, one which may be another first for our coast. While working on a pelagic seabird survey for the Canadian Wildlife Service onboard the Canadian Coast Guard vessel J.P. Tully, he spotted a mysterious, small, domed-shaped object poking out of the water far offshore of the west coast of Vancouver Island.
Luke’s experience at sea has made him exceptionally observant. “During these surveys, I have to pay attention to every little detail,” he explains. On the survey, he had already observed many odd-shaped objects in the open ocean, including a beautiful Japanese glass fishing float, but he knew this was different. His first reaction was one of exhilaration and surprise, “wow, that is a sea turtle.”
While all sea turtles are relatively rare in B.C. waters, several leatherback sea turtles (Dermochelys coriacea) are spotted each year along our coast. The Vancouver Aquarium’s B.C. Cetacean Sightings Network has accumulated nearly 200 recent and historical sightings of these ocean giants.
The turtle floating alongside the Tully was not a leatherback, however. It wasn’t a green sea turtle either, the second most commonly observed sea turtle in B.C. with 36 sightings. That meant that Luke’s turtle was either an olive ridley (Lepidochelys olivacea) or a loggerhead (Caretta caretta), both exceptionally rare in these waters. Only three olive ridleys have been confirmed on our coast, and no loggerheads (although they have been reported in neighboring Washington and Alaska).
Hard-shelled sea turtles can be identified by observing small differences in the scutes (scales) on the head and along the shell, as well as by small differences in the shape of the shell. But it was going to be tough for Luke to figure out which sea turtle it was. Obscuring his ability to accurately identify the animal was the fact that he couldn’t see many of these key features. Although it was alive, the animal was covered in a thick layer of algae.
What would make a turtle so fuzzy? Scott Benson, a marine ecologist with NOAA’s Marine Turtle Ecology and Assessment Program, has also observed algae coated turtles in Monterey Bay, California, though none quite as covered as Luke’s sighting. He attributes these algae layers to the animal moving slowly in cool water with high productivity. As reptiles, sea turtles slow down considerably in cold water giving the abundant algae a chance to establish on their bodies.
When the algae growth hampered identification attempts on his own, Luke reached out to experts at Fisheries and Oceans Canada and the Marine Turtle Ecology & Assessment Program at the Southwest Fisheries Science Center. The algae growth impedes a definitive identification, but after some careful consideration, the experts conceded that they were 80 per cent certain that the animal was a loggerhead due to the angular shape of the shell, the broad base of the skull and the colouration of the few scales on the animal not covered by algae.
While 80 per cent is not quite a confirmed record, this sighting is still a first in B.C. waters. “This is the first ‘possible’ loggerhead we’re putting into our sea turtle sightings database,” confirms Tessa Danelesko, the B.C. Cetacean Sightings Network coordinator who collaborates with Fisheries and Oceans Canada to amass sea turtle records in B.C. “Through using a network of observers who live and work on the water and who report their sightings, we are learning much more about sea turtle occurrence on our coast. We want to encourage anyone that has seen a sea turtle in B.C. to report it and help us better understand these animals.” Sightings, both current and historic, can be reported to the Sightings Network online at wildwhales.org or via phone at 1 866 I SAW ONE.
For Halpin, he feels excited to have contributed to yet another first for B.C. He says, “The one thing I’ve learned is you never know what you’ll see out there. Always keep your eyes on the water.”
Learn more about loggerhead sea turtles at wildwhales.org.