San Diego Historical Society

Turtles at San Diego wharf, c. 1910

At the bottom of San Diego Bay, in the shadow of a huge SDG&E power station in Chula Vista, lives a colony of endangered sea turtles. They have been present, more or less, since the facility was built in 1960. Nobody knows where they came from or even how they got there. But a few people have tried pretty hard to find out.

Two biologists from Hubbs Marine Research Center are now studying the South Bay turtles, and eight other researchers from around the country have expressed a desire to do the same. These 200-pound reptiles don’t really belong in the bay — they are, after all, sea turtles — which makes them especially interesting to scientists. But sea turtles in general are a hot environmental topic, right up there with dolphins and whales. Most species of sea turtles nest on Mexican beaches, and all of them are now either threatened or endangered. Last week, the Mexican government finally banned turtle hunting, but not before doing some serious damage to the turtle population.

Capturing turtles near the South Bay power plant

But the South Bay sea turtles are living a happy life, swimming in a narrow, mile-long inlet of water. There’s plenty of eel grass to eat, and the power plant discharges a plume of warm water that is perfect turtle temperature. Best of all, the general public is kept away by shallow depths and the SDG&E security force. As long as the turtles stay in the channel, there are no boat propellers to cut off their heads, no water skiers to run over their backs. It’s a turtle’s definition of paradise.

But San Diego has not always been so hospitable. During the last century, it was a maritime port for turtle hunters who prowled the Baja coast. One of them, a rather inept fellow named J.C. Bogart, may even be responsible for the modem population of turtles. It’s a far-fetched theory, but so is the idea of a sea turtle swimming to Chula Vista from Hawaii. These are the sorts of thoughts that keep biologists up at night.

Sea turtles were always a good source of food for merchant and explorer ships. They were easy to catch and easy to store; just toss a few below deck, turn them on their backs, and water them down every so often. Turtles die slowly, so they kept fresh for weeks.

Donna McDonald, Peter Hutton

Photo by Dave Allen

Whaling ships also fed their crews on turtles but at some point began selling them. Thousands of sea turtles moved through the San Diego port, where they were either bought by local restaurants or shipped to San Francisco by steamer. When Captain J.C. Bogart arrived in August of 1857, the San Diego Herald announced that he was carrying 40 sea turtles in his whaling vessel. A month later the newspaper reported that the turtles had broken out of their holding corral on the dock of Aspinwall’s Island (now North Island) at high tide. Captain Bogart sailed back down the coast, captured 120 more turtles, and returned to San Diego two months later. He built another pen but was plagued once again by design problems. Almost half of the turtles escaped.

Most of the escapees made tracks for deeper waters, but some apparently decided to stay in San Diego. In the decades that followed, newspaper accounts show that sea turtles were present in large numbers in both San Diego and Mission bays. Local fisherman tried shooting them from the wharf (which was prohibited) but eventually resorted to nets. Any turtles foolish enough to bask in the mud on the Dutch Flats (now Lindbergh Field) often found themselves hauled ashore and flipped over, helplessly awaiting their fate in the family stewpot.

Turtle soup could be found on the menu of the Hotel del Coronado, and Horton House offered turtle steak for dinner. Some of the larger turtles — weighing 1000 pounds and up — escaped the dinner plate only to become a sideshow. Local eateries would put them on display as a way of attracting patrons. In 1888 the owner of the Saddle Rock restaurant was arrested for obstructing the sidewalk in front of his business with a giant turtle. The case went to trial, much to the delight of the local press. A jury declared the man not guilty.

In 1919 a turtle processing plant, Blackman Cannery, opened in National City. By this time, the turtle population was starting to drop. In 1922 the Mexican government began restricting turtle hunting in its waters. When the supply side of the market dwindled, so did the demand. The public had never really developed a taste for turtle meat anyway. Blackman Cannery closed in 1930, and turtle hunters were getting stuck in San Diego harbor with cargos that no one wanted. In the mid-1930s, three local turtle schooners switched their operations to commercial albacore and sportfishing.

As for the turtles residing in the bays, no one is sure of their fate. The newspapers stopped writing about them in 1903, but some people recall seeing them in Mission Bay in 1945. Sea turtles live a long time — estimates range between 40 and 100 years — so it’s possible that some of the 1857 escapees never left. Or maybe they made San Diego their home base and populated the bay with their children and their children’s children.

This theory was suggested by Margie Stinson, an SDSU graduate student, who did the first research on the South Bay turtles. Stinson conducted an exhaustive study for her master’s thesis (the source of much of the historical data mentioned above), which was completed in 1984. She began her study in 1977, after the captain of a local fishing vessel told her about the South Bay turtles. Stinson hoped to discover where they came from, which meant finding out where their nesting grounds are.

Many biologists believe that a “genetic imprint” causes the turtles to return to their birthplace when it comes time to mate and lay eggs. Sea turtles are related to land tortoises; they have common ancestors that once crawled into the ocean and learned how to hold their breath for up to an hour. Their feet turned into flippers, and at some point, they lost the ability to withdraw into their shells.

Female sea turtles are driven, it seems, by an immutable biological program: crawl up on the beach, dig a pit, lay the eggs, cover them with sand, return to the ocean, and swim away without looking back. Some species show no reaction when biologists take their eggs from under them; they never see their offspring anyway.

But when it comes to sex, sea turtles are like most species; they have their quirks. Foreplay consists of three or more male turtles lurking around a female until one of them makes a go for it. The others begin biting him on the head, while he, in turn, sinks his beak into the female’s neck. Older sea turtles, especially males, are usually covered with scars on their heads and necks.

Turtles mate for hours at a time, with some sessions lasting all day. Because of their lovemaking stamina, sea turtle eggs are considered an aphrodisiac in Mexico. The eggs are stolen from the nests and then sold in village markets. As a result, some species of sea turtles are near extinction.

For years environmentalists have pressured the Mexican government, which is the world’s chief exporter of turtle products, to close the state-owned slaughterhouses and ban hunting altogether. Last year Mexican officials allowed 20,000 turtles to be killed legally, with an estimated 40,000 more falling into the hands of poachers. The turtles are turned into lotion, boots, belts, handbags, soup, and steaks. Tortoise shell combs (made from the Hawksbill turtle) are popular wedding gifts in Japan, which imports more turtle products than any other country.

So it’s possible that some of the South Bay turtles wound up in the freezer case at Calimax. Stinson postulated that the local population was migrating down the Baja coast each year. She found no evidence of turtle nesting in the bay. and the turtles seemed to disappear from the channel each summer. Were they leaving town for the beaches of Mexico or simply seeking cooler waters in another part of the bay? To find the answer, she attached small tracking devices to the shells of six turtles. (After several unsuccessful attempts at catching them, Stinson had to travel down the Baja coast and ask Mexican turtle hunters to show her how.) The idea was to follow the turtles’ movements through ultrasound waves. But Stinson had trouble with her receiving equipment, and the transmitters kept falling off the turtles. At one point, her 13-foot skiff was stolen from the channel. A sheriffs department ASTREA helicopter eventually located it, and Navy Seal divers retrieved the lost transmitters, but Stinson had to give up on the tracking devices. She turned her attention to another part of the study, one that had little to do with her hypothesis. But it turned out to be the more valuable information.

Stinson distributed thousands of sea turtle sighting forms to marinas and commercial boat landings along the Pacific coast. Fishermen from Southern California to Alaska cooperated by keeping logs of sea turtle sightings, complete with information on the turtles’ size, shape, and behavior. Stinson collected the forms over a five-year period. She combed through museum files and research journals for references to other sightings.

The survey she compiled was extensive — 363 turtle sightings in all.

Sadly, many of the reports dealt with dead or injured turtles. Some had drowned in unattended fishing nets or become hopelessly tangled in crab pot lines. Others were caught by fishing poles or injured by the propellers on boats. The fate of these turtles depended largely on the humans who found them. Most commercial fishermen, aware of the turtles' endangered status, turned them loose if they were still alive.

(Or called a local wildlife agency if they appeared sick. Many of Sea World’s resident turtles were acquired this way.) But with sport fishermen, it was the luck of the draw. In five of the six reported instances of fishing pole ensnarement, the turtles were released. Number six was apparently reeled into the boat, gaffed, and then killed by gunshot. This particular turtle, a leatherback, washed ashore in 1981 at Moonlight Beach in Encinitas. A necropsy at the San Diego Zoo (by the National Marine Fisheries Service) found that its throat had been slit; .22-caliber bullets were extracted from its shell. The biologists discovered two old gunshot wounds.

Stinson’s survey was important simply because so little was known at that time about sea turtles in the northeastern Pacific Ocean. Unfortunately, no part of her master’s thesis was ever published. Technically, the seven-year-long study had been a failure. Because of equipment problems, Stinson could not determine where the turtles went when they left the channel. And since none of the ones she captured were wearing any identification (biologists began tagging turtles in the early 1960s), Stinson could only speculate on where they came from. Maybe Mexico, maybe Hawaii, or maybe even Captain Bogart’s slipshod turtle pen.

Peter Dutton won’t rule out the Captain Bogart theory, but he thinks that the green sea turtles in the South Bay are probably from Mexico. (Some biologists would call these turtles “blacks” instead of "greens,” as the two species are closely related. It’s the sort of thing that turtle experts argue about.)

Dutton and his research partner, Donna McDonald, began a $9000 study on the turtles last May, with funds from the U.S. Fish and Wildlife Service, the county’s Fish and Wildlife Advisory Committee, and Hubbs, the research institute affiliated with Sea World. Their study concluded this month, with a dusk-to-dawn turtle roundup.

During the work week, Dutton manages a fish hatchery program at Hubbs, one that is restocking Mission Bay with white sea bass. But he’d rather be working full time with turtles. “I couldn’t make a career in turtle biology,” Dutton explains. “There’s no money in it. I had to get a real job.” He has studied sea turtles in Mexico and in Surinam, which he describes as “a mosquito-ridden mango swamp” in the Caribbean. After he was forced out of Surinam by a military coup, Dutton enrolled in the graduate program at SDSU.

It happened to be Margie Stinson’s last year. Dutton heard about her project and sat in the audience while she defended her thesis. Then he got busy with other things, but the South Bay turtles continued swimming around in his thoughts. All he needed was another turtle person.

Donna McDonald became enamored with sea turtles on a remote beach about 300 miles southwest of Guadalajara. This is one of the locales where green sea turtles and other turtle species lay their eggs. In an effort to combat the poachers, biologists from the University of Michoacan have set up a preservation program. They give talks in the nearby schools about the fragile condition of the species, then they pay the local kids — many of whom have worked for poachers — to bring them the eggs instead. “The kids are really good at it too,” says McDonald. “They’re very patient. It can take a turtle two hours to find a spot, lay her eggs, and bury them. The kids just lay there on the beach and nap while she’s digging." The eggs are then reburied on protected beachfront land. After the turtles hatch, they are released into the ocean.

McDonald studied turtles at the Sea World in Texas. (The Gulf of Mexico has several species of sea turtles.) Like Dutton, she works on other projects during the regular week. The two biologists met at Hubbs, where they naturally started talking about sea turtles. Dutton asked McDonald if she knew about the colony of greens living next to the power plant. Then they started wondering if the turtles were still there. Soon they were working together on a grant application.

The two biologists started their turtle study at the same place Stinson's ended: the SDG&E power station in Chula Vista. The electrical generating plant, which is visible from the L Street exit on Interstate 5. seems like an odd location for a colony of endangered sea turtles. Right next to the channel is an eight-story mangle of turbines, condensers, and emission stacks that always seem to be buzzing, blinking, clanking, or humming. Yet if it weren’t for the pumping station, the turtles wouldn’t be there. They are attracted by a plume of 80-degree water that flows into the channel after it cools the steam condensers. (Sea turtles cannot stand cold water; it sends them into a torpor, they stop eating, and eventually they become emaciated.) The turtles are somewhat protected by the shallow water of the southern bay outside the channel. (Dutton and McDonald once saw a bikini-clad woman walking near the mouth of the inlet, her little girl in tow. Their boat had run aground in the shallow bay, she said, and why weren't there any warning signs?)

On the land end of the man-made lagoon, public access to the turtles is practically nil. SDG&E’s property is surrounded by a chain-link fence and a security gate. But the turtles are not entirely alone. Shrimp and sea horses have also been found near the inlet. And the channel abuts a wildlife preserve set aside for the Least Tern, an endangered species of bird.

Dutton and McDonald have been making weekly visits to the channel since last May. Mostly they’ve been counting the heads that bob up (turtles surface for air every 3 to 20 minutes) and making sure that the animals were still there. For some reason, the turtles didn’t leave the channel last spring, as they were expected to do. And it looks as if they may be hanging around again this summer. Green sea turtles nest every two or three years, so maybe they’re just taking a breather. But for all anyone knows, some could be leaving while new ones arrive.

Margie Stinson estimated that 30 turtles lived in the lagoon, but the Dutton/McDonald head count has only identified six. (One they call Barney because of the barnacles on his head, and another, Wrinklebutt, has distinct creases on the back of his shell. Wrinklebutt fits the description of a turtle in Stinson’s study.) The researchers won’t be able to get an accurate number until they catch and mark each turtle. The other question in their study is the turtles’ point of origin. If they catch any that are wearing tags, the answer will be obvious. A more sophisticated method — DNA mapping — will also be used. This involves analyzing samples of the turtles’ blood for similarities to other populations.

Last February the two biologists stretched their turtle-catching nets across the channel for the first time. They waited five hours but caught nothing. The same thing happened the next time they tried. On their third attempt, a young turtle wandered into the net at sunset. Then came an all-night excursion in early May that yielded four turtles and one shovel-nosed guitar fish (“It looks just like it sounds,” says Dutton). Unfortunately, none of the turtles were wearing identification tags. But there was one big bonus. “Luckily a turtle dumped on our deck, so we got a fecal sample,” says Dutton. The turtles were also weighed, measured, tagged, photographed, and released back into the bay. The biologists' final attempt to capture turtles was another all-night vigil on May 26.

It’s shortly before dusk when Dutton and McDonald arrive at the power station, along with two colleagues who’ve agreed to help. None of them is aware of the long and almost turtle-less night that awaits them. The researchers stretch a net across the near end of the channel, not far from the dock, and another one farther out, at the lip of the lagoon. Sometime around 9:00 p.m., they climb into their 17-foot Boston whaler and motor out to check the nets. No turtles yet. Another look at 10:30. Still no turtles. Every hour or so they make another trip to the nets, only to find them empty.

The in-between times are spent sitting in beach chairs and eating quiche, taco chips, and chocolate-covered espresso beans. The thermos coffee begins to get cool, and the air becomes downright cold. Throughout the night, their conversation touches on unpopular co-workers, puppies, and television shows, but it always comes back to the turtles. Are they hanging at the bottom of the channel, waiting for the tide to go out? Or have they learned how to avoid the nets?

Finally, about 4:00 a.m., the floats on the closest net begin to bob. It’s turtle time! The two assistants, who by now have fallen asleep, are roused. Everyone stands on the dock, ready to board the boat, when the net becomes perfectly still and stays that way. The turtle has apparently escaped, or maybe he was never really in there. This teasing goes on several more times, until the next scheduled check on the outer net.

By now the sky is showing pink brushstrokes. Cars come down the Silver Strand one by one, their headlights spaced far apart. The tide is moving out, and the water is lightly rippled, like dripping paint The power plant hums in the background, but out in the channel, it’s quiet and still.

Except for the bobbing floats.

“He’s a big one,” says Dutton, immediately recognizing the turtle’s sex. Two people hold it against the boat, their hands under its fins, while Dutton untangles the net. No one seems worried about being bitten. (Dutton later explains that green sea turtles are vegetarians and not that aggressive.) Then comes the hard part: lifting a turtle that weighs at least 200 pounds over the side of the boat. It takes four people and a lot of grunting.

Back on the dock, McDonald examines the turtle by the beam of a flashlight, pointing out his color (a greenish black) and a possible tag scar. The skin on the turtle’s fins is surprisingly soft and dry, like a lizard’s. The pattern on his head looks like a flagstone path. His eyes are glazed over with a salty mucus; this is how turtles sweat. McDonald says he has “bad breath” but is surprised that the turtle doesn’t have a fishy smell. His shell is unusually clean — no barnacles or algae. And like the other turtles they’ve caught, this one has no visible effects from pollution. “Greens are showing up in Hawaii and the Caribbean with lesions and tumors,” says Dutton.

“Here we are in a polluted bay, and the turtles are healthy.’’

A scale is rigged up on the boat's boom, and the turtle is carefully weighed: at 125 kilograms (270 pounds), he’s the biggest one yet. After a series of measurements, McDonald takes two syringes of blood from a vein in the back of his neck. The turtle doesn’t flinch. Nor does he react to the two metal bands clipped to his front flippers or the green plastic tag stapled onto his back leg. All will eventually fall off, Dutton says, so several are attached in hopes of retaining identification as long as possible.

Every so often McDonald tells the turtle he’s a good boy and pats him on his shell. He seems a bit dazed, or maybe just mentally impenetrable. The researchers claim that he’s “mellow” but admit that sea turtles are not especially intelligent creatures. After an hour-long examination, Dutton makes an announcement: “A2782 is tagged and ready to go.” The turtle is loaded back into the boat for a trip to the outer net.

By now the sky has lightened and the tide is all the way out. Mud fiats appear along the sides of the channel. Dutton and McDonald look out over the bay, their faces a bluish-grey color. It’s probably a reflection off the water, combined with some degree of fatigue. They say they need to catch more turtles, but it’s obvious that they’d also like to go home. An hour later, after the sun is up, they grab the end of the net and try to encircle a group of bobbing heads. But they capture the same turtle again and release him straightaway. At 9:47 a.m., a juvenile turtle swims into the near net. It’s a new one they haven’t seen yet. This makes seven different turtles they’ve nabbed, plus Barney and Wrinklebutt, who eluded capture.

The results from the DNA blood tests won’t be ready until later this month. Turtle researchers in Hawaii and Mexico are anxiously awaiting the lab results. They want to know if any of “their” sea turtles have shown up. Although this data will be the most conclusive, the researchers make some preliminary observations: judging from the size, shape, and color of the turtles, all were from nesting grounds along the Baja Coast. One, however, looks like a Hawaiian.

Dutton and McDonald hope to get another grant so they can attach either radio or satellite transmitters to some of the turtles. The radio devices (which would be similar to Stinson's but more sophisticated) would let them know if the turtles leave the bay. The satellite equipment could track the turtles around the world. Their funding prospects look good. But first they have to file reports with the agencies who’ve already given them money. The U.S. Fish and Wildlife Service, which is responsible for protecting endangered and threatened species, has asked for a set of recommendations on what to do with the turtles. “Right now there’s no management plan for them," says McDonald. She and Dutton will suggest that the Least Tern nesting area and the turtle channel be combined into one nature preserve. This might satisfy the ornithologist they encountered while measuring their last turtle. She stood on the dike overlooking the channel and scolded them for disturbing the birds.