Entanglement by marine debris is a serious issue plaguing California and Steller sea lions along the west coast of North America.
Ghost fishing gear, including nets and ropes, and discarded trash such as the plastic strapping used in packaging and shipping, become snared around the necks of the marine mammals, often killing them as they grow larger. Surveys in British Columbia have documented hundreds of entangled sea lions; similar numbers are estimated in California, Oregon, Washington and Alaska.
The Vancouver Aquarium Marine Mammal Rescue Centre has been disentangling sea lions in British Columbia since 2013, in collaboration with Fisheries and Oceans Canada. Over the past two decades, head veterinarian Dr. Martin Haulena has helped develop a precise drug combination to temporarily sedate a sea lion so it may be carefully handled. The procedure to remove the entangled gear often takes place in the water, from a boat, with a floating animal. “These rescue efforts involving sea lions are extremely challenging and can be dangerous,” said Haulena. “Success depends upon ideal weather and ocean conditions, and requires specialized equipment and a skilled team.”
Last week, it was an international team of veterinarians, wildlife officials and biologists who carried out Washington State’s first disentanglement rescues of sea lions by remote immobilization. Over two days, two adult male California sea lions were saved from painful injuries and potential death after the team sedated each by dart, removed the packing straps entangling them, reversed the anaesthetic and observed them as they returned to normal behaviour. The rescues were conducted under a U.S. federally issued Marine Mammal Protection Act/Endangered Species Act (MMPA/ESA) Research and Enhancement Permit.
Organized by NOAA’s Marine Mammal Stranding Coordinator for Washington Kristin Wilkinson, the team included Dr. Haulena and Vancouver Aquarium associate researcher Wendy Szaniszlo as well as additional biologists from the NOAA Fisheries Alaska Fisheries Science Center Marine Mammal Laboratory; veterinarian Dr. Joseph Gaydos, SeaDoc Society /UC Davis; and veterinarian Dr. Lesanna Lahner and Casey Mclean from Emerald Waters Marine Wildlife Health Institute.
The trip was based from Neah Bay, on Washington’s outer coast, home of the Makah Tribe, which also supported the rescue efforts by providing boat support and the aid of marine mammal biologist Jon Scordino. He surveyed for entangled sea lions in the region ahead of the trip along with Billy Monette and Pat Gearin of NOAA Fisheries. In addition, marine mammal biologist Brian Fadely — who is based in Seattle and works with NOAA fisheries through the Marine Mammal Laboratory — assisted with the disentanglements. He’s previously worked with Dr. Haulena with endangered Steller sea lions in Alaska to help understand their biology and promote conservation of this species that is also affected by marine debris in Washington and British Columbia.
On Sunday, Oct. 2, the first adult male California sea lion was immobilized remotely from shore by Dr. Haulena, and disentangled from a vessel by Dr. Lahner. The next day, Oct. 3, another male California sea lion was darted on shore by Dr. Gaydos and disentangled by him and Dr. Haulena.
“We’re excited to be bringing this safe, but technically challenging technique into Washington,” said Gaydos.” Disentanglement not only improves the welfare of the animals we help, but also enables us to collect data needed to identify the main items entangling sea lions so we can help manufacturers alter their production and stop the entanglement cycle.”
Unfortunately, the sea lions rescued this week are not alone in their injuries, but NOAA cautions that sea lions are large, wild animals and rescues should not be attempted by the public.
Pinniped entanglements in Washington and Oregon should be reported to the stranding hotline at 1-877-767-6114. Since this is a new program, response areas are limited; disentanglement attempts will be made in areas that are determined to be safe for personnel and that have adequate response capacity. Generally, disentanglement responses are focused on areas where elevated numbers of entangled animals have been identified over a long period of time. Highly populated areas, marinas, boat ramps, etc. are not likely areas to be targeted locations for interventions.
If you see a stranded marine mammal in B.C., do not approach it and keep pets away. Call the Vancouver Aquarium’s Marine Mammal Rescue Centre at 604.258.SEAL (7325) for immediate assistance.
Vancouver Aquarium Marine Mammal Rescue Centre
The Vancouver Aquarium Marine Mammal Rescue Centre, presented by Port Metro Vancouver, is a hospital for sick, injured or orphaned marine mammals. The Rescue Centre rescues stranded marine mammals and rehabilitates them for release back into their natural habitat. www.vanaqua.org/mmr.