East Pacific green turtles are year-round residents of southern California waters, where they forage on sea grass and invertebrates in shallow bays. However, as the Pacific ocean warms and climate change shifts habitats, turtles are traveling farther north more frequently. Venturing into northern regions where water temperatures can drop rapidly puts these marine reptiles that cannot regulate their own body temperatures at risk of cold-stunning and stranding on land.

Dr. Heather Harris, who serves as Upwell’s Wildlife Veterinarian and Associate Veterinarian for The Marine Mammal Center, has been leading a collaborative cold-stunning study to learn more about the health status of hard shelled sea turtles that travel into northern latitudes. As part of this study, Dr. Harris provides stranded sea turtle response training and protocols to improve their survival outcomes to collaborators up and down the West Coast. When the biologists of the Pacific Gas and Electric (PGE) Diablo Canyon Power Plant found a juvenile green turtle floating in the intake cove last December, they knew exactly what to do, thanks to this training.

Divers loaded the small turtle into a hanging basket which was lifted by crane to the platform above. As per the cold-stunning protocol, the turtle was placed in a padded box in the shade to avoid rapid warming or cooling, which can cause severe physiologic changes that lead to various health complications. The Marine Mammal Center, a member of the NOAA West Coast Stranding Network and a key collaborator in the cold-stunning study, responded with a field team that brought the turtle back to their field office in Morro Bay where Dr. Harris examined it.

The turtle was referred to there as Chairlift, in reference to the unique basket retrieval system developed by PGE for this purpose. Dr. Harris found that Chairlift was mildly hypothermic, just at the body temperature threshold at which sea turtles can become inactive and unresponsive. The turtle was in good body condition with adequate fat stores. However, Chairlift had a previous injury on its left front flipper that had healed abnormally and required additional medical attention.

The Marine Mammal Center transferred the rescued sea turtle to the Aquarium of the Pacific in Long Beach with authorization from the National Oceanic and Atmospheric Administration’s (NOAA) Fisheries office for a medical evaluation, surgery, and care because of the Aquarium’s expertise in treating and releasing stranded and injured sea turtles. 

After 5 months of excellent care by the aquarium’s animal care and veterinary staff, the turtle  was ready to be released back into the wild. Hoping to find out more about the turtle’s movements and habitat use, Upwell provided a micro-satellite tag that was applied by our Executive Director Dr. George Shillinger. These micro-satellite tags were developed by Lotek Wireless engineers in partnership with Upwell as part of Upwell's Lost Years Initiative to find out more about how smaller juvenile turtles (like Chairlift) use their ocean habitat. On May 16th, the Aquarium of the Pacific released the turtle back into the ocean in Seal Beach, CA near a population of green turtles. 

Since the release, Chairlift has stayed in coastal areas within and around the Seal Beach region. Chairlift’s tag transmitted positions around the inner Long Beach waterways including the San Gabriel River watershed, where other green turtles have been observed, and the Port of Long Beach. Chairlift's use of this habitat highlights the need for continued monitoring and mitigation of turtle-human interactions in the area. The Aquarium of the Pacific has a Community Science Sea Turtle Monitoring program that people can join as volunteers. In addition, citizen scientists can report sea turtle sightings through the Sea Turtle Spotter Project. 

The micro-satellite tag that Upwell deployed is designed to be tiny and light, perfect for smaller turtles like Chairlift. However, these adaptations also make the tag a bit less hardy than its full-size counterparts, and the shallow waters filled with debris and rocky surfaces which Chairlift has been inhabiting will most likely take a toll on the attachment, and therefore tag retention. Many of the positions transmitted had a wider margin of error than usual, most likely caused by interference from structures in the surrounding environment paired with brief satellite passes creating limited successful transmissions. In these conditions, when a tag stops transmitting it usually implies the tag’s useful life is over but indicates no threat to the turtle’s well-being.

Cold-stunned turtles like Chairlift have stranded on beaches from California up to British Columbia, Canada. With climate change, the frequency of these events is only expected to rise. In partnership with members of the NOAA West Coast Stranding Network, Dr. Harris is collecting further data that can be used to improve health outcomes for stranded sea turtles. Furthermore, turtles that can be rehabilitated provide a unique opportunity for insight into their movements and behaviors in our waters. The data from Chairlift’s tag will help inform us about how green sea turtles that venture into northern waters are using habitats off of the California Coast, which is critical information for creating targeted conservation strategies in the context of climate change. 

Chairlift's healthy release and tagging is a happy ending that would not have been achieved without the quick response and collaboration of the PGE biologists, The Marine Mammal Center, the Aquarium of the Pacific, and Upwell – it truly takes a village! At Upwell, we are grateful to these partners and the wider NOAA West Coast Stranding Network as well as our supporters around the globe for making this critical work possible.