Turtle Tracks

Did you know that the largest Eastern Pacific green sea turtle ever recorded has been known to spend time in San Diego Bay? The turtle, affectionately known to local scientists as “Wrinklebutt” due to the unique deformity of her shell, weighs in at a hefty 550 pounds!

Researchers from the Marine Turtle Research Program at the NOAA - Fisheries (National Oceanic and Atmospheric Administration) Southwest Fisheries Science Center captured, weighed, and released her on February 1, 2006, as part of an ongoing green turtle research project in South Bay. A satellite transmitter was attached to her shell, allowing researchers to track her movements for several months until the transmitter's battery expired in late June 2006.
How does this local-record holder like to spend her time in San Diego Bay? She probably enjoys foraging on eelgrass and resting in the warm water throughout South Bay. Dr. Peter Dutton, Dr. Jeff Seminoff, and researchers at SWFSC mapped her movements to learn how this enormous turtle makes use of different habitats within her environment, and whether she ever migrates out of San Diego Bay. Throughout the 4-month period during which the transmitter provided information, “Wrinklebutt” did not appear to leave the bay.

Map: Last Known Locations of "WrinkleButt"

Check out the map to see her last known locations in San Diego Bay.
Map Last Updated: 1/25/2007 at 3:58PM

Do sea turtles really live in San Diego Bay?

Green sea turtles, along with all six other species of sea turtles, are listed as either threatened or endangered under the Endangered Species Act. This means that they face a risk of extinction in the wild. Green sea turtles are often found from July through September off the coast of California. The southern portion of San Diego Bay supports a year-round population of approximately 60 turtles, who can often be seen foraging in eelgrass beds throughout South Bay. Local researchers have used genetics and satellite telemetry to determine that the turtles are part of the Eastern Pacific nesting populations, and migrate thousands of miles to lay their eggs on beaches off the coast of Mexico. Along this incredible route, the turtles encounter the dangers of long lines, fishing nets, freighters and naval ships. Within San Diego Bay, the turtles can most often be seen surfacing within the South San Diego Bay National Wildlife Refuge, which provides a protected foraging and rest area, as well as a prime study site for turtle biologists. The turtles’ greatest threat in San Diego Bay is being hit by boats traveling over the 5-mile/hour speed limit present throughout the southern portion of the bay.

Is “Wrinklebutt” a long-term resident of San Diego Bay?

“Wrinklebutt” was captured in San Diego Bay for the first time in 1976. Her captor, Margie Stinson, a graduate student at San Diego State University, named her, fed her a pill-sized device to measure body temperature and attached a tracking device to her shell. At that time, “Wrinklebutt” weighed 392 pounds. Researchers were astonished by her ponderous weight as they tried to carry her across a stretch of mudflat to a truck waiting to transport her for an overnight stay at Sea World. At Sea World, marine veterinarians helped assess her and attach her tracking device. Stinson was able to nestle the tracking device into the unusual depression in her shell, and the tracking device remained attached for two and a half years.

Since then, the turtle has become somewhat of a local legend due to her massive size and distinctive shell. This made it easy for researchers to recognize her when she was resighted regularly throughout the 1980s and 1990s. Up until recent events, the turtle had not been sighted for several years, which led to growing concern over her demise. Researchers were delighted not only to discover “Wrinklebutt” in good health during her recent capture, but even more impressively that she now weighs an astounding 550 pounds, making her possibly the largest member of her species in the eastern Pacific! Two types of transmitters (acoustic and satellite) were attached to her shell, and provided valuable information about her habitat use and movement in San Diego Bay. Clearly, “Wrinklebutt” is a long-term resident of the bay.

What does the future hold for turtle-tracking in San Diego Bay? Through funding partnerships with the Port of San Diego and the Navy, the NOAA-SWFSC Marine Turtle Research Program scientists are attaching acoustic tags to turtles and deploying an array of automated listening stations in South Bay. The research is being conducted under NMFS Research Permit #1297 under the authority of Section 10 of the Endangered Species Act. Each listening station will determine the presence or absence of the tags’ acoustic transmissions within the station’s vicinity. Researchers will retrieve data periodically from the listening stations, allowing them to track the movements of green turtles in the bay on a much finer scale to get an even better sense of habitat use. Hopefully, “Wrinklebutt”, along with other tagged green turtles, will provide some insight into a typical day in the life of this remarkable threatened species.

To learn more about other sea turtle tracking studies throughout the world, visit SeaTurtle.org