Environment
In the last two decades, scientists, educators and activists across Southern California have joined forces to help out the population of upwards of 60 green sea turtles.
The moment a familiar reptilian pops its head out of the water is not the easiest task to capture on camera, but is a typical sight during kayak outings in the South Bay.
In the last two decades, scientists, educators and activists across Southern California have joined forces to help out the population of upwards of 60 green sea turtles inhabiting major hotspots like San Diego’s Bay and La Jolla Cove year-round.
According to the National Oceanic And Atmospheric Administration (NOAA), East Pacific green turtles (Chelonia mydas) are listed as threatened under the Endangered Species Act. However, in recent years, the green turtles in the eastern Pacific have experienced conservation success thanks to the collaborative efforts of locals.
“You question whether you see them because their head just pops up,” says Tracy Tempest, a Coronado Cays resident in late December as she prepares for her last kayak trip of the year.
Tracking sea turtles from the Cays
On a typical week, Tempest kayaks 3 to 4 miles in two to three hours on three different days, observing and tracking sea turtles from the Cays and all throughout the South Bay.
When she comes across one or several turtles, she documents the GPS location, their behavior, and sends the information to NOAA.
“As I’m kayaking, I go up to pretty much every boat you see or jet ski and if they’re going fast, I make a gesture to please slow down,” says Tempest who began her volunteer work during COVID and now continues to spend time in the water alongside fishermen and other people hoping to educate the public about the sea turtles, especially during the winter.
“I could talk turtles forever because of the scientists, I’ve learned so much from them,” says Tempest, who was recognized by NOAA for her significant sea turtle sightings contribution throughout COVID when scientific field work was halted.
Tempest, 68, has since participated in captures and releases, experiences that ignite her desire to continue learning about sea turtles and helping to protect turtles.
“It’s amazing just what I’ve learned in two years thanks to them,” adds Tempest, who was also named Emerald Keeper of the Month in April 2022 for her citizen scientist work with the species.
Scientists at work
At the NOAA Southwest Fisheries Science Center 30 miles north of Coronado, Jeffrey Seminoff, a marine ecologist, tells The Coronado News about the fascinating sea turtles locals may encounter from Chula Vista to La Jolla, sea animals he has worked with since the 1990s.
“San Diego’s distinctively home for a lot of green turtles. …They have fidelity to San Diego.”
Jeffrey Seminoff, marine ecologist
“San Diego’s distinctively home for a lot of green turtles. They will live here for decades at a time. When they reach maturity and start to do their reproductive migrations to Mexico, they might be gone for eight months to a year, but they have something called foraging site fidelity,” says Seminoff. “They have fidelity to San Diego.”
According to Seminoff, adult females and males have been living in San Diego Bay for 20 to 30 years.
While these sea turtles swim to nesting beaches in Michoacán, Mexico, they make back and forth journeys to San Diego to restore their energy so they can reproduce some three or four years later.
Tracking movements of sea turtles
“Another tool that we commonly use to study sea turtles in San Diego and Southern California is something called satellite telemetry…a small device that gets glued to the back of a sea turtle,” said Seminoff, who currently leads the Marine Turtle Ecology & Assessment Program at NOAA’s Marine Mammal and Turtle Division in La Jolla.
“We’re able to track the movements of those animals simply from satellites,” adds Seminoff. “We identify what countries need to work together in cooperation to protect the species.”
The Division’s study of green sea turtles has proved positive in affecting a significant returning population. The telemetry work with green turtles in San Diego Bay, allowed the team of researchers to understand the importance of working closely with “Mexican colleagues to protect the species,” said Seminoff.
“Every year we have more and more turtles, especially juvenile turtles, …we’re getting better and better at safeguarding our sea turtles.”
Sabrina Mashburn, SoCal Sea Turtles Executive Director
“Every year we have more and more turtles, especially juvenile turtles, which is amazing. And it means that between the nesting beaches in Mexico and the foraging grounds here in Southern California, we’re getting better and better at safeguarding our sea turtles,” says SoCal Sea Turtles Executive Director Sabrina Mashburn, who worked with Seminoff and his team to tag and track Trey, the first adult male green sea turtle that kept his tag on and returned to the Bay.
Raising awareness
While green sea turtles are the primary species in San Diego’s backyard, Seminoff notes that “California’s turtles are an international bunch.”
“Leatherback sea turtles occur along the central California coast, and they originate from nesting beaches in Indonesia and Papua New Guinea and the Solomon Islands. And then during warm water periods like El Niño, like this coming El Niño that we have right now, there are a species called the Loggerhead sea turtle that comes into Southern California waters, and they all come from Japan,” said Seminoff.
For this reason, collaboration among scientists in the lab and the field with community scientists has proved helpful to raise awareness and spread education that can help visiting, and permanent sea turtles continue their life journeys.
“We have a lot of responsibilities besides just San Diego Bay sea turtles, …To have somebody like Tracy who, to this day, still helps us, it’s a Godsend…”
Jeffrey Seminoff
“We have a lot of responsibilities besides just San Diego Bay sea turtles, so we aren’t able to be down there as much as we like to be,” said Seminoff. “To have somebody like Tracy who, to this day, still helps us, it’s a Godsend because it really allows us to keep a track of what’s going on when we’re out there.”
Climate change, feminization
However, the species may face short- and long-term survival threats.
Seminoff said he considers climate change and feminization existential threats “happening over a long timeframe.”
“Sea turtles don’t have sex chromosomes. They don’t have an X and a Y, they have only X chromosomes. And the sex of an individual is determined by the temperature at which that individual incubates in its egg. It activates certain enzymes, certain hormones, and warmer nests produce females, cooler nests produce males,” said Seminoff.
In 2015, Seminoff and his team examined the sex ratio in San Diego Bay and found a sex ratio of four females to every male.
“My suspicion is that the sex ratio is going to be even more female biased today. And we’ve seen that throughout the world. There’s many beaches where the same thing is happening,” said Seminoff. “If you start to reduce the number of males, you get lower than one, then we have a real problem. We’re starting to see in some places like Australia where this problem of feminization is becoming incredibly profound to the point where soon we may start to see a reduction in the numbers of nests being deposited on beaches.”
Escaping natural predators
According to NOAA, hatchlings on the beach must escape natural predators like birds, crabs, raccoons, and foxes to make it to the sea. Once in the water, they must also face survival with seabirds and fish which then leaves few that survive to adulthood, with estimates ranging from one in 1,000 to one in 10,000.
Although climate change has shown a direct impact on the Olive Ridley species nesting in new places, Seminoff said green sea turtles have not shown a significant change in nesting locations.
“There’s efforts around the world to artificially incubate nests in cooler environments or to build shade structures over the beach so that the sand gets shaded and it stays cooler,” says Seminoff. “But when you think about the vast range of sea turtle nesting behavior and the nesting beaches around the world, it’s such a massive spatial scale that the work that we’re doing as scientists is just a small portion of those beaches.”
Other threats include accidental captures on hooks and boat strikes, with the latter being the primary of a “pretty fast and painful death.”
In this respect, NOAA in partnership with SoCal Sea Turtles continues to expand student and adult sea turtle conservation education related activities which includes signs with pictures of turtles warning boat goers to slow down in various marine areas.
Protecting turtles in Imperial Beach
And according to Mashburn, this year SoCal Sea Turtles will also work with the City of Imperial Beach to develop signage specific to the pier regarding sea life and especially sea turtles in the Spanish language.
Regarding how local sewage affects the species, Mashburn, who obtained her Master of Applied Science in Marine Biodiversity & Conservation from Scripps Institution of Oceanography, considers there is a possibility that there may be an eventual impact of correlation with regard to their diet.
“The official answer is no, there are not direct effects from pollution on sea turtles, but as a scientist and ecosystem person, I think there are a lot of organisms that are deeply affected by pollution, like mollusks and seaweed and a lot of smaller invertebrate organisms, and the sea turtles are eating these organisms,” said Mashburn.
“If the pollution is affecting the population size of available prey items, then the sea turtles will eventually be affected.”
Sabrina Mashburn
“If the pollution is affecting the population size of available prey items, then the sea turtles will eventually be affected. And so I think it’s less about the sea turtles getting chemical poisoning and more about the sea turtles’ environment being degraded and then them having less opportunity to feed in the areas where they expect to find food.”
Mashburn also said she considers that sea turtles, like other reptiles, are “resilient to pollution.”
“We could end all the causes of sea turtle deaths that are not natural, which would be amazing,” said Mashburn. “Outreach and education and advocacy, coupled with being careful when you’re around the water with your fishing debris and slowing down.”
Top three ways to protect sea turtles
Additionally, Mashburn shared the top three things that can be done to protect sea turtles:
- Make sure that you’re going slow on a boat or your jet ski if you’re near shore, as it “really could save sea turtles and marine mammals’ lives.”
- When fishing, have the marine mammal and turtle hotline number at hand and clean up your line and your hooks, because “you could be saving a sea turtle’s life.”
- Help spread the word. Make a post on social media. Tell your friends.
“Despite the fact that green turtles have really exploded in population in Southern California, I still do think that it’s one of the best kept biodiversity secrets in our region.”
Jeffrey Seminoff
“Turtles are a wonderful example of animals that connect habitats. They connect countries, they connect communities,” said Seminoff. “Despite the fact that green turtles have really exploded in population in Southern California, I still do think that it’s one of the best kept biodiversity secrets in our region.”
