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Collaborative research helps save cold-stunned sea turtles on the Pacific Coast

Emeline McMann-Chapman is a recent graduate with a BS in Biological Sciences and a minor in Environmental Studies from California Polytechnic State University, San Luis Obispo. As an Upwell Research Assistant, she assists with collection and analysis of stranding data on cold-stunned sea turtles on the Pacific coast. Emeline is documenting the temporal and spatial trends of cold-stunning events and compiling patient medical data to better understand their underlying health conditions. She is also contributing to the development of new cold-stunned sea turtle intake guidelines for organizations involved in sea turtle rehabilitation on the US West Coast.

When I imagine sea turtle habitat, I think of pristine, clear water that is very warm: water that I would swim in without a wetsuit. I definitely never thought hard-shelled sea turtles, like olive ridleys, loggerheads and green turtles, would live in the rough, freezing waters of the eastern Pacific, but they can and do. These turtles are cold, just like the water, because they are ectotherms and cannot produce their own heat.

Hard-shelled sea turtles travel north along the west coast of North America following warm water currents to forage and are usually able to swim south once things begin to get too cold. Some are not so lucky. Turtles that cannot reach warmer waters will experience hypothermia and are termed ‘cold-stunned’ because they are often unable to move due to lack of heat. When cold-stunned turtles show up on beaches, this is known as a stranding event. Sea turtles have washed up on the Pacific coast as far north as Canada.

Only a handful of sea turtles cold stun each year on the Pacific coast of North America and, as of now, there are no established trends or predictors of when they will arrive on Pacific beaches. Successful rehabilitation of these cold-stunned turtles is challenging because we don’t know much about their underlying health conditions. Several years ago, Upwell started an initiative to try and fill in these information gaps by connecting the organizations of the NOAA West Coast Stranding Network to contribute data to a region-wide study to learn more about the health status of cold-stunned sea turtles along our coast. Upwell Veterinarian Dr. Heather Harris is leading this collaborative research project, and it is also receiving funding from the Oiled Wildlife Care Network. 

Dr. Harris reached out to me during my fourth year of undergraduate study at California Polytechnic State University, where she also serves as faculty. Before I knew it, this massive cold-stunning research was my senior project and would then become my first job after college. I dove right into the medical records for over fifty turtles. I sorted through thousands of pages of both typed and hand-written records logging the stories of these turtle popsicles.

My preliminary data on the demographics of Pacific cold-stunned turtles established that there is not much predictability or regularity to cold-stunning events on the Pacific coast. The most unfortunate finding was that only about a quarter of Pacific coast cold-stunned sea turtles survive to release back into the ocean. This number is drastically lower than the rate of release on the east coast, so our next task was to figure out what else is going on within these turtles. 

A crucial part of figuring out why any organism did not survive is to look inside of it, so we needed to get our hands on as much information about these turtles as we could, particularly their necropsy reports. A necropsy (animal autopsy) is a process where you thoroughly examine a dead specimen and identify any significant findings that may have led to its death. Then, two study collaborators, the Oregon Coast Aquarium and Oregon State University Marine Mammal Institute, let us know that they had seven frozen sea turtle specimens ready to be necropsied.  This begged the question, how were we going to transport frozen sea turtles from Oregon to California, and where would we take them?

Turtle Flyers from the organization Turtles Fly Too played a critical role; these pilots were the ones flying our turtles. Turtles Fly too typically helps to fly live turtles in need of transport and plays a key role in saving sea turtles during mass cold-stunning events on the East coast by bringing them to centers near warmer waters for their rehabilitation and eventual release. We were so grateful they were willing to fly our unconventional passengers.

Turtle Flyers Tina and Jeffrey Blum standing next to their plane, photo by Jackie Isbell

The Turtle Flyers who helped us, Tina and Jeffrey Blum, said “We love to fly and are always looking for a way to share our passion for aviation.” I must say they accomplished this, because this research could not have been done without Tina and Jeffrey. 

The Marine Mammal Center is a key collaborator on the cold-stunning study and graciously offered to host the necropsy session and contribute their extensive expertise in marine wildlife pathology. Once the turtles arrived at the hospital in Sausalito, CA, it was time to get to work. I was eager to learn what we could from  the necropsy process. I knew these turtles better than anyone, their whole story from the day they showed up cold-stunned on the beach to the unfortunate day they died. I was so excited to finally figure out what exactly had been going on inside of them, why they did not survive. We are finally going to get some answers. These turtles may not have survived, but they are now contributing to research that will help to save future cold-stunned turtles. 

Left to Right: Necropsy Technician Jackie Isbell of The Marine Mammal Center, Dr. Heather Harris, and Emeline McMann-Chapman conduct the necropsy on a deceased sea turtle, photo by Bill Hunnewell © The Marine Mammal Center

The Marine Mammal Center Director of Pathology, Dr. Pádraig Duignan, and Dr. Heather Harris

This cold-stunned turtle project has made it more than clear to me that research in the modern scientific world is not simple; it takes not only time, energy, and money but also cooperation, communication, and dedication. Transportation of seven specimens of sea turtle from Oregon to California required highly coordinated partnerships. The collaboration of five different organizations all eager to contribute to sea turtle research is an amazing feat, and I am very grateful to have been a part of it.

Cover photo: A cold-stunned olive ridley sea turtle washed up on a California beach, photo by Heather Harris

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