Right now, in early June, giant creatures lurk a mere mile off the Monterey coast. These leviathans can grow up to 8 feet long and weigh 2,000 pounds. For perspective, a Steinway concert grand piano tips the scale at 990 pounds; a Holstein dairy cow 1,500; and the curb weight of a classic 1970 Volkswagen Beetle is 1,918. These highly endangered gentle giants are known to scientists as Dermochelys coriacea; the rest of us call them Pacific leatherback turtles. A scientific research organization based in Monterey is dedicated to tracking the leatherback population with the goal of understanding their behavior and possibly fending off their impending extinction.
Upwell was founded in 2017 by seasoned scientific researchers Dr. George Shillinger and Dr. Kristin Reed, who now serve as Upwell’s executive director and operations director, respectively. The nonprofit’s stated mission is “to protect endangered sea turtles by reducing threats at sea, including fisheries bycatch, ship strikes, pollution, climate change, and other detrimental human activities.”
That’s a tall order, given that the Pacific Ocean alone covers an area of nearly 643 million square miles. Sure, leatherbacks are large, but still, that’s a lot of watery ground.
Leatherbacks are the last of a class of reptiles that have plied Earth’s oceans for more than 100 million years. They are unique in that their shell—or “carapace”—isn’t solid like those of most of their brethren. It’s soft and, well, leathery.
“These turtles have a suite of adaptations that allow them to do things other turtles can’t. For example, they can dive deeper than any other in search of food, up to 1,300 meters [4,265 feet],” says Shillinger. “The flexible carapace allows their bodies to compress at the tremendous pressure at those depths. They are also ‘endothermal,’ meaning that because of their huge mass they can regulate their body temperature. That’s an almost mammal-like trait.”
Also unique is their diet. Shillinger calls them “jellyvores” because, “Leatherbacks consume prodigious quantities of jellyfish.” Prodigious indeed. Adults must ingest 20 and 40 percent of their body weight every day to meet their daily energy needs. That’s a lot of jellies, and there are plenty of those in the chilly waters of the Central Coast. What aren’t there plenty of? Leatherback turtles.
According to a brochure published by Upwell, leatherbacks as a species are in extreme danger. There are two populations of these benign behemoths, known as the West Pacific and East Pacific. The former has declined by more than 78 percent and the latter by 90 percent.
“The Eastern group is the most endangered,” Shillinger says, “they’ve declined 99 percent in the last three generations—30 years—with complete extinction currently expected by 2080. The Western is predicted to be gone by 2100.”
Why? These reptiles cover huge distances in their search for food, and like a few other species, they do a remarkable thing: return to the beach where they were born to lay their eggs in the sand.
“The Western population hatches in Indon-esia, Papua New Guinea, Vanuatu, and the Solomon Islands,” Shillinger explains. And they swim here to dine on delicious Monterey jellyfish. The distance from Vanuatu to Carmel is 5,858 miles as the seagull flies and there are plenty of perils along the way, mostly man-made. Danger is present at every phase of a leatherback’s life. Poachers (human and non) snatch their eggs from their sandy nests and birds and other wildlife pick newborn baby turtles off while they’re making the mad dash to sea, where other predators lurk.
If they survive to adulthood, they are vulnerable to becoming bycatch to the fishing industry. Shillinger says there is no market for their meat, and many times if a turtle’s flipper gets snared in a longline hook the boat crew will simply cut off the fin to save the hook. Because they like to rest near the surface and bask in the sun, many turtles are struck by passing ships.
And another extreme danger is posed by something that looks a lot like their favorite food. In the depths of the ocean a common plastic shopping bag bears a striking resemblance to a jellyfish.
The first step in the effort to intervene and turn the tide of leatherback extinction is to better understand the species’ behavior. To that end, Upwell is engaged in an ambitious program of tracking that entails tagging the animals with satellite transmitters so their wide-ranging movements can be analyzed. A boat is directed to individuals that have been located by spotter aircraft. Scientists safely capture the huge animals, take blood samples for analysis, and attach harmless tracking devices. Maximum time out of the water is 45 minutes.
“We want to minimize handling time as much as possible,” Shillinger says.
Upwell is concentrating on studying leather-backs between the Monterey area and the Farallon Islands west of San Francisco, and Shillinger says that his organization has gathered significant data in just a few years.
“Before ours and others’ tracking work, there was zero information about leatherback movement and habits.”
But there’s lots more to be done. “We have our work cut out for us in terms of raising awareness of how important it is to conserve these animals.”
For further information on the plight of the leatherback turtle and how we can aid in their preservation, visit upwell.org.