Saturday, October 08, 2005

The Saga of Long Island Sound's Sea Turtles (written in '90 for This Fine Piece of Water but didn't make the cut)

The first Kemp’s ridley floated ashore, camouflaged by rockweed and sea lettuce, at a beach in Riverhead, Long Island, on November 12, 1985. Others followed. The tides and gentle waves carried them up and back, washed them toward the Sound’s beaches, and dropped them in a dark line of tide wrack on the gravel and sand. Most of the turtles were dead. Three were barely alive.

Usually, when a large dead sea creature comes to rest on a beach in New York, Sam Sadove hears about it, sets out in his pickup truck, and carts it away. Sadove is the research director of the Okeanos Ocean Research Foundation, which has a contract with the State of New York to keep the state’s beaches clean of dead marine animals, generally whales and dolphins on Long Island’s Atlantic shore. Sadove is a marine mammalogist, and any whale or dolphin he finds on a beach is his for dissection and necropsy. But autumn and winter are the slow season for this kind of work, so in November of 1985 he traveled to a conference in Vancouver, British Columbia, confident that little would happen in his absence.

In fact, the events he missed marked the start of a drastic change in the way scientists think about the rarest of the world’s seven species of sea turtles.

“I came back from Vancouver and the staff told me we had three live ridleys,” Sadove recalled, “and I said, ‘What the hell do you mean, live ridleys?’ ”

Kemp's Ridley Turtle poster

For the next month and a half, Okeanos, an organization based in Hampton Bays, Long Island, recovered an average of one ridley a day, forty-five in all. Forty percent had been washed up onto the fifteen miles of beach between Wading River and Riverhead. On December 8 alone, the island’s North Shore became the resting place of seven ridleys, a green turtle, and a loggerhead turtle — their final resting place, as it turned out, for as the temperature of the Sound dropped with winter’s onset, the sea turtles, which are cold-blooded, had no chance. Water that in early November might have left turtles stunned and comatose, but still alive, in December killed them. The three ridleys recovered by Okeanos when Sadove was in Canada, and several others that bobbed ashore soon after his return, were lucky to be living.

Alive or dead, the appearance of a Kemp’s ridley turtle in Long Island Sound in November was considered extremely unusual. Anne Meylan, a herpetologist on the staff of the American Museum of Natural History, told me that whenever she heard of foundling Kemp’s ridleys she assumed the reports were wrong: the level of familiarity with sea turtles in general is low, and the Kemp’s ridley in particular can be hard to put a name on.

"The species has a history of being misidentified," she said. "I didn’t believe they were ridleys until I laid eyes on them."

My first look at a ridley came on a winter’s morning when I visited Meylan at the museum. I met her at a side entrance, before the museum opened for the day, and followed her through a maze of dark exhibition halls to her windowless laboratory. On a table was a handwritten reminder: "Thaw out turtles." Nearby, in a jar, a preserved specimen floated nose up. A label said the carcass had been found in Riverhead, on December 8, 1985 — it was one of the seven recovered on that busiest day of the stranding season.

Meylan opened the jar, lifted the turtle out of its pickling liquid, and showed me how to identify it.

She ran her finger along the carapace, or upper shell. "The diagnostic characteristics are the shape of the carapace — it’s almost round," she said. "They’re the only turtle that can be wider than they are long." This turtle’s shell resembled a soup dish, about a foot in diameter, and was the color of wet slate. She counted the costal scutes, the plates that run along the edge of the carapace. Five on the left, five on the right, which narrowed the choices: if I had found this turtle on a beach on the east coast of the United States I could assume it was a loggerhead or a Kemp’s ridley. She turned the animal over and counted the inframarginal scutes, the plates on the bridge that separates the carapace from the plastron. Each side had four. That clinched it. This was a Kemp’s ridley, one of two hundred and eighty sea turtles that have been seen in or recovered from the waters around Long Island since 1985. More than half of those have been in the Sound, and one hundred sixteen have been ridleys, each one, on average, weighing about nine pounds and with a shell-length of almost twelve inches.

"These large numbers of Kemp’s ridleys," wrote Steve Morreale, Okeanos’s director of sea turtle research, "represent the largest concentrations of this species ever reported outside of the Gulf of Mexico and greatly exceed all previous records in northeastern waters."

Volunteer beach-combers have plucked turtles from the gravel strands running west from Orient Point to Sands Point. Pound net fishermen working the North Fork have scooped them out of traps. Morreale has tracked them across the Sound to Stratford, Connecticut, and west almost to Throgs Neck. And everywhere, it seems, people who are interested in sea turtles have perked up at the news, which has thrust this poorly understood creature, seemingly as dim-witted as they come but with origins contemporaneous with the dinosaurs, into prominence like never before.

Seeking pronouncements and explanations, many who hoped to learn what was going on called Archie Carr, the scientist who, until his death in 1987, was considered the world’s expert on sea turtles. In a column published in Animal Kingdom magazine, Carr noted that following the sightings and strandings in New York, "an epidemic of curiosity erupted."

"I was never before so beset by telephone inquiries," he wrote.

Those who lay siege to his phone included me. I reached him at his home, near Gainesville, where he was graduate research professor at the University of Florida. He seemed happy to talk — happy to tell me, like all others, that my hopes of answering many questions about the Kemp’s ridley were a fantasy.

The one thing scientists are most sure of about the ridley, he said, is that they know very little — which, I later learned, was the kind of debunking assertion that Archie Carr was fond of. In a paper published in 1980, for example, he had tweaked the scientific community, himself included, when he wrote that "an impressive feature of the recent World Conference on Sea Turtle Conservation … was the elementary state of our knowledge of their ecology."

That knowledge is so elementary, he told me over the phone, that zoologists have little idea where Kemp’s ridleys spend their lives — whether it is in bays or estuaries, in the open ocean, in deep water or coastal shallows. "It’s quite possible," he said, "that there’s been lots of ridleys in Long Island Sound that we’ve never known of."

It turns out, though, that Carr had had more than just an inkling that ridleys regularly migrated north in greater numbers than anyone knew for sure. In the 1980 paper, which was published in a journal called American Zoology, he had noted: "Numerous … recent records suggest that New England might be a regular station in the developmental ecology of a part of the species."

He was alluding, in part, to what Meylan had referred to — the species’ history of being misidentified. For years in the late nineteenth and early twentieth centuries, museums had collected small sea turtles taken from northern waters, labeled the specimens Caretta — the genus of the loggerhead turtle — and stored them away, all but forgotten, in the institutions’ collections. Then in the 1930s, Carr wrote, scientists who were only recently persuaded that the Kemp’s ridley was a distinct species began rummaging through the specimen cases for another look. The re-examinations showed that many of the sea turtles were not Caretta at all, but Lepidochelys kempi, the Kemp’s ridley. And, if the preserved remains were not enough, fresher evidence confronted researchers: a flotilla of ridleys caught in Buzzards Bay one summer in the 1930s, for example; a ridley, stunned by the cold waters of Vineyard Sound, recovered from a beach on Martha’s Vineyard in the spring of 1956.

But the turtles that Okeanos was finding were in New York, not New England, and so in 1985 and 1986, Anne Meylan — a former student of Carr’s — and the scientists at Okeanos conducted their own historical search. They discovered that a man walking a beach in the North Fork town of Southold one day in 1924 had come upon one hundred and three dead sea turtles, both ridleys and loggerheads. [Morreale, Meylan, Brigitte Baumann] They found two ridleys taken from the Sound, one in the 1930s, one in the 1950s, in a collection at a museum in Albany. They ferreted out a paper published in the Bulletin of the New York Zoological Society, in 1931, which said ridleys "are frequent summer visitants to Northern harbors" and are "the species most commonly found in New York waters." And they found a paper that listed the shell of a small turtle — a ridley or a loggerhead — among the artifacts dug up by archaeologists on Long Island at a prehistoric Indian site.

A truth was emerging, one far different from the conventional wisdom of previous decades.
Carr told me he believed the ridleys made their way north from the Gulf of Mexico via the Gulf Stream. As the stream flows past North America’s east coast, he said, warm eddies break away and swirl over the Continental Shelf. The ridleys probably get caught in the eddies, which probably carry them toward the Sound.

"It’s a complicated thing and other people have opinions," he said, "but I’ve thought about it longer than anybody. It was a puzzle to me then and it’s a puzzle to me now."

He added, "I’m sorry I can’t give you a more definite piece of information, but anybody that does, you must distrust him."

From Archie Carr that was sage advice, for he had spent forty years searching for the most important information of all about the Kemp’s ridley.

******

"The lights went out. A switch snapped and the screen lit up with an aerial view of a long, straight beach, bordered by broad surf .... the cameraman ... turned his lens down the shore. And there it was, the arribada as the Mexicans call it — the arrival — the incredible crowning culmination of the ridley mystery. Out there, suddenly in clear view, was a solid mile of ridleys. ... You could have run a whole mile down the beach on the backs of the turtles and never set foot on the sand."

In his book So Excellent a Fishe, Carr described how the scientific world came to learn where and how — via a film he first saw in 1961 — the Kemp’s ridley nests. It was a short film, in black and white, faded and scratchy with age. But its technical qualities were irrelevant. "For me really, it was the movie of all time," Carr wrote.

The film was made by Andrés Herrera, a Mexican engineer, who had heard about a sea turtle spectacle so great it overwhelmed a beach north of his home, in Tampico, in the Mexican state of Tamaulipa: "It was said they came ashore there on any unforeseeable day between April and June and on some unpredictable mile on ninety miles of uninhabited shore," Carr wrote.
Herrera was a pilot who became friends with a photographer from Mexico City who, hearing Herrera talk about the sea turtle arribada, decided he wanted to get it on film. With Herrera at the controls of his light plane, they began skimming the beach in the spring of 1947. The first week revealed nothing. Likewise for the second. After three weeks all they had seen was sand and sea. During the twenty-fourth day the cameraman became sick, and that night he decided the limit of his tolerance had been met. He would search no more. Before he left, though, he lent Herrera his camera. During the twenty-fifth flight, above Rancho Nuevo, Herrera saw the ridleys lumbering out of the gulf and, in a sand-flying frenzy, dropping their eggs onto the beach.

At the time, of course, Carr had no knowledge of the arribada, nor would he until 1961, although not for lack of effort. He had interviewed fishermen in the Gulf, for example, but they had told him the turtle was sterile and that it nested nowhere. That theory had some acceptance for a while, and the bastard-turtle or the mule-turtle, as some called it, was considered a sterile hybrid of the green turtle and the hawksbill. The fishermen Carr interviewed had a different name for it — they called it the ridley. Carr thus began using the name, and it stuck, although he admitted he had no idea what ridley meant.

Along the Gulf coast of Mexico, local inhabitants called the same turtle cotorra, or parrot, presumably for the beak-like shape of its head and mouth. Carr encountered three in Vera Cruz, in the form of shells, painted red, and hung on the outer wall of a cantina. He was visiting that remote area — one stop on a long trail that had taken him to the Azores, where a small ridley had been found, to Portugal, Spain, Africa, and Brazil — because he had learned of a purchase, made of a fisherman in Vera Cruz, by two American college students tramping through Mexico: a purchase of two very young ridleys.

Driving north from Costa Rica, his wife and young children along for the adventure, Carr "had stopped at every coastal town accessible from the Pan-American Highway and at each stop I had gone through a routine ransacking of the place for turtle clues. I searched the fish markets, walked the beaches looking for tracks, poked about garbage dumps after shells and bones, and quizzed all the fishermen I could stimulate to talk, to hear what they would tell."

Eventually he saw the red shells. The man who ran the cantina told Carr the turtles had been captured nearby, on their nesting beach. There was evidence only of three turtles, hardly enough to sustain the populations he and others had encountered in the Gulf of Mexico and the Atlantic Coast of Florida, but to Carr it was "a sudden sign that the old ridley mystery might one day really end." It was as close as he would get to solving the mystery until that day in the darkened room in Austin.

The discovery of the film was the work of Henry Hildebrand, who at the time was a biologist at the University of Corpus Christi. He had found Herrera in 1961, while pursuing rumors of mass turtle nestings. Herrera told him he had seen such an event and in fact had a movie of it. Hildebrand arranged for its premier at the meeting in Austin, but to be sure the turtles were Kemp’s ridleys, he gave Carr a preview. To Carr’s astonishment, the film showed ten thousand ridleys laying their eggs on the beach. Hildebrand calculated that another thirty thousand turtles took part in that day’s arribada — a total of forty thousand nesting Kemp’s ridleys.

"The world," Carr wrote, "suddenly seemed to me a place in which anything can happen."
Unfortunately for the ridleys, much more — and much worse — had happened at Rancho Nuevo.

One hint had come shortly before Carr saw Herrera’s film, when, as he wrote in his Animal Kingdom column, he heard rumors that "an Arab egg merchant had been seen on the ruinous road between Rancho Nuevo and Tampico, driving a train of 14 burros loaded with turtle eggs," carting them on the first leg of a journey to sate the Mexicans’ desire for a food they considered an aphrodisiac, and which could be found, pickled in large jars, on the bar of cantinas throughout the country.

More evidence — indisputable — was documented in the film, which, as if to dull the euphoria of a mystery solved, showed frame after frame of ridleys laying eggs, only to have men catch them before they hit the ground and collect them into piles — "the most turtle eggs I ever saw in one place," Carr wrote.

Still later, he heard that after World War II, poachers made yearly raids, hauling the eggs to markets, across the sand and rugged terrain, in Army-surplus four-wheel-drive vehicles.
Hildebrand estimated that in 1961 as many as ninety percent of the nests were destroyed the same day the eggs were laid. A book called The Great Ridley Rescue quotes him as saying,

“Estimates I heard of eggs taken from the first arribada of the year varied from ‘a few used by ranchers for food’ to 20 to 24 truckloads of 80,000 eggs each, going to markets nearby.”
The poachers also worked on the water, destroying more than just nests.The Great Ridley Rescue , written by Pamela Phillips, reports that as egg-laden females would move toward shore, waiting boats grabbed thousands of animals, slicing them open to steel their eggs.
The plunder was annual. It was an egg-stealing orgy. In the words of Larry Ogren, a former student of Carr’s and now an endangered species specialist with the U.S. government, it was a "systematic harvest of every nest." And, since each female ridley lays about one hundred and five eggs a year, the one arribada caught on film may alone have supplied four million eggs for a market that must have been all but insatiable.

By the time Carr saw Herrera’s film, the arribada of forty thousand ridleys already was history. The early 1960s saw only five thousand turtles coming ashore in any one year. And the steady year-by-year drop did nothing but grow more precipitous. By the middle of the 1980s, only about five hundred ridleys lumbered out of the sea at Rancho Nuevo.

Throughout Carr’s long search, he had heard rumors and seen documentation that ridleys nested elsewhere, at least occasionally, or once upon a time. A particularly tenacious rumor continually pointed to southern Vera Cruz. A friend investigated for Carr and heard of great aggregations of cotorras , but their arribadas were in the past. If they nested at all now, it was one by one. In 1948 and 1950, a county engineer in Corpus Christi, Texas, came upon two ridleys nesting on Padre Island, a long barrier beach on Texas’s Gulf coast. They became the subjects of the first published accounts ever of nesting ridleys. And of course there were the three from the cantina in Vera Cruz. Nor are such incidents unheard of even today: astonishingly enough, a ridley nested on a Florida beach in 1989.

Yet in their insubstantiality and singularity, these isolated nestings proved mainly that if there was hope of keeping the ridley from extinction, work would have to start at Rancho Nuevo.
And so it did. Mexico began watching over the arribada in 1966; eleven years later it accepted the United States government’s offer of help. Since then, an army — including Mexican Marines — equipped with walkie-talkies, three-wheeled vehicles, and an airplane, has protected "every turtle and every nest on that beach," said Jack Woody, the national sea turtle coordinator for the U.S. Fish and Wildlife Service. Mexican and American workers watch every turtle lay her eggs and, before any predator or plunderer can get to them, remove the eggs to man-made nests in protected corrals.

"On most days during the four-month nesting season only a few turtles, or none at all, are seen nesting - sometimes there will be no turtles on the beach for a period of ten or eleven days,” Phillips reports. “Other times are busy with around 20 to 50 arriving on the same day, and on two or three random days each season a small arribada of 80 to 150 turtles will come ashore to lay their eggs. When this happens, the beach workers are hard-pressed because nobody can rest that night until all of the eggs have been moved into corrals.”

The guards watch over the nests until they hatch and the hatchlings reach the sea — fifty thousand half-inch long, 1.6-ounce ridleys each year since 1977.

"If we weren’t there,” Jack Woody told me, “that would be the end of it."

Yet, despite the money and the effort and the good intentions, the survival of fifty thousand baby ridleys each year may only prolong the inevitable. I have yet to talk with any expert who looks forward to the future of the Kemp’s ridley — who truly believes the turtle has any future to look forward to.

More than two decades ago, in So Excellent a Fishe, Carr observed: "There can be no doubt that the Atlantic ridley is in a critical position. It has always been obviously vulnerable." Nowadays, biologists often refer to the Kemp’s ridley as the world’s most endangered sea turtle. And although the Fish and Wildlife Service demurs initially — "When you try to compare species it’s almost impossible to judge which is more endangered," says David Klinger, a press officer for the service — it also considers "sea turtles to be one of the most highly endangered group of species in the world."

Woody told me, "Even with the protection we’ve given them, every year the population is down. It could be biologically extinct and we don’t know it." Nor might we realize it for many years. Turtles are well-known for living long lives; green turtles, for example, probably do not even begin to reproduce until they are thirty or forty years old, according to Carr. If ridleys are favored with a similar Methuselah-like quality, they can be expected to fade from the planet only with excrutiating slowness. But, the consensus seems to indicate, fade they will.

So why do embers of optimism burn? Perhaps it’s our own species’ capacity for hope. Perhaps it’s what biologists tell themselves when they are working hard on a problem that is likely to be unsolvable. And perhaps, because nobody interested in sea turtles wants the ridleys to die out, every hopeful indication, no matter how tiny, is scrutinized to find some way to say responsibly: this is the sign we’ve been looking for. Jack Woody himself suggested I ask Larry Ogren about recent events in his territory.

Ogren works for the National Marine Fisheries Service, out of an office in Panama City, in the Florida panhandle. His domain includes the coast of Florida, Alabama, Mississippi, Louisiana, and Texas. In the 1960s he made a point of looking for Kemp’s ridleys and asking fishermen about them. "We had none at all," he told me. But in recent years that has changed. He believes he is seeing what he calls "a demographic shift in the population."

Since 1985, "I’ve started looking for them in coastal marshes and I’m getting more and more of them," Ogren said. "They can be quite common. We’re seeing an abundance in some areas — no kidding."

It is to the ridleys’ great misfortune, however, that they are also abundant in places less conducive to a long and healthy existence — namely, in the Gulf of Mexico and Atlantic waters that are crisscrossed by fleets of shrimp boats. The word "controversial" does not nearly convey the fury of the disagreement between those who catch shrimp for a living and those who are trying to save the Kemp’s ridley. To some observers, in fact, the shrimp boats, and not the plunder at Rancho Nuevo, are to blame for the decimation of the ridleys’ breeding population. Archie Carr, for example, believed that because turtles were so long-lived, the decline happened too soon and too fast to blame on the egg stealing.

"It seems more probable," he wrote in Animal Kingdom, "that the reduction in nesting turtles reflects mainly the growth of the shrimp industry, which extracted ridleys of all ages from the population."

The relationship between sea turtles and shrimp is a scary example of how an economy that can easily transport food thousands of miles from its source can, with no second thoughts, cause profound ecological problems. There is, essentially, no reason why shrimp should be, if not a staple, then a regular luxury for people who live nowhere near the smell of salt water and the power of the tides. Yet, as Jack and Anne Rudloe noted in an article about sea turtles and shrimpers in the December, 1989, issue of Smithsonian magazine, "run-down luncheonettes a thousand miles from the sea can be counted on to serve deep-fried butterfly shrimp."

Americans eat almost two and a half pounds of shrimp per person each year, the Rudloes reported. A demand of that size spawns a big industry: In the United States alone, seven thousand boats annually trawl between four million and five million hours in offshore waters alone, while another eleven thousand trawl inshore. In 1988, the Rudloes reported, U. S. trawlers landed three hundred and thirty-one million pounds of shrimp, worth $506 million. Imports accounted for another four hundred and seventy-one million pounds.

It would be hard to begrudge the industry its bounty if it were one that inspired praise for the conservation of resources. But that is far from the case. The Rudloes report that for each pound of shrimp the trawlers catch, nine pounds of other marine animals die incidentally. Ted Williams, writing in Audubon magazine, says the ratio sometimes reaches twenty to one.
A big part of that ratio can be made up each time a trawler hauls in a sea turtle. And government statistics indicate that a net full of loggerhead or ridley is not a rare occurence. In his book Time of the Turtle, Jack Rudloe — using observations made by Larry Ogren — describes how a sea turtle gets caught by a shrimp boat. The turtle was a loggerhead, not a ridley, but Ogren told me the point is the same. Rudloe wrote:
"First, the two iron-shoed otter doors approached, and the frightened turtle turned and began swimming straight ahead, trying to outrun them. They can exceed speeds of twenty miles an hour, while the net creeps along at four. But instead of veering off to the side with a single stroke of its powerful flipper, the big dull-witted creature kept swimming straight ahead.

"The net came on relentlessly, and the turtle began to tire. With each spurt forward it made less distance and used more energy than on the previous spurt. Soon the doors were ahead of it. It began to drop back, making a few more desperate spurts before it entered the mouth of the net, became pinned to the webbing, and was forced into the funnel along with the rest of the catch, hopelessly carried along."

According to the National Marine Fisheries Service, the seven thousand shrimp trawlers that work offshore catch, on the average, about seven sea turtles each a year. Fewer than two of those die as a result. It hardly seems to be a problem, until you do the multiplication: forty-eight thousand sea turtles caught, eleven thousand two hundred dead. Of those, almost ten thousand are loggerheads, a threatened species. About seven hundred sixty-seven are Kemp’s ridleys. In other words, each year at least two hundred more ridleys die in shrimp nets than nest at Rancho Nuevo.

The shrimp industry’s response to these statistics and accusations is angry. There is no way shrimpers account for so many turtle deaths, they say. And even if it were true, so what? Are turtles more important than the economic health of the shrimp industry? The shrimpers’ protests have grown more bitter as environmental groups have succesfully sued the federal government to force it to obey the endangered species act —obedience in this case meaning the use of mechanisms called TEDs, turtle excluder devices.

TEDs come in several designs, each basically an outlet in the net. When working properly, a TED allows turtles and other large animals or objects to slip back into the sea before reaching the net’s pocket. Shrimp stay caught. TEDs would seem to be a good solution to turtle mortality, except that shrimpers say the device is nothing more than a hole in the net that cuts their shrimp catch by twenty percent. The shrimpers have pressured politicians, enlisted the support of United States Commerce Secretary Robert Mosbacher, and organized mass acts of civil disobediance to protest the use of TEDs. But so far, at least, their protests, while upsetting the timely adoption of TEDs by the industry, appear to have fallen to the power of the Endangered Species Act. It is not a moment too soon, although it may ultimately all prove to be too late.

But before the end arrives — if it arrives — scientists far north of the Gulf of Mexico intend to make the most of what has been an unprecedented chance to study the Kemp’s ridley. Until 1985, when the first ridleys were stranded on the beaches of Long Island Sound, all research on the ridleys had essentially been limited to Rancho Nuevo and Padre Island. The state of wildlife biologists’ knowledge about the Kemp’s ridley in 1985 resembled Carr’s assessment of the knowledge of sea turtles in general in 1980 — elementary. So although the Okeanos Ocean Research Foundation was making truly new discoveries, some of the discoveries seemed notable for their obviousness.

Carr, for example, told me he believed that Kemp’s ridleys of the size being found in the Sound were creatures of the plankton — they could move their flippers to swim but could not navigate and so were forced to rely on tides and currents to transport them. Okeanos quickly saw this was not so. One turtle, found cold-stunned but alive in 1985, and nursed back to health during a winter in captivity, was released into a salt marsh at Mount Sinai Harbor. Sam Sadove and Ed Standora, a professor at the State University of New York at Buffalo, watched from an inflatable, outboard-powered boat and followed it as it swam toward the Sound. At four meters per second, the tide was coming in hard. The boat floundered. "We attempted to capture the animal,” Sadove reported, “but found it was impossible to swim in the inlet against the incoming tide. The turtle, however, had no difficulty negotiating the ... current." The young ridleys were not as helpless as Archie Carr had thought.

Nor was much known about how fast ridleys grew. So whenever Sadove got a cold-stunned turtle that was still alive, he weighed and measured it. One particular turtle had a carapace length of just over ten inches and weighed six and a half pounds when it was first recovered in 1985. In early August of ’86, when Sadove released it and began tracking it, it was about a foot long and weighed almost nine pounds. Four months later, when it was found dead on a beach, it had grown to almost fourteen inches and its weight had ballooned to more than fourteen pounds.

"That is extremely significant," Sadove told me in early 1987, "because there’s no data on wild-growth rates."

For Sadove in those early days, that was about as strong a statement as he would make about the ridleys. Even the most obvious observations were related with a wariness of definite pronouncements. After releasing two turtles into a marsh near Stony Brook, for example, he sat up all night in his boat listening to the beep beep beep of the transmitters he had attached to their shells and noting their movements. The turtles surfaced regularly for air but otherwise remained still. The nighttime movements of a turtle he released into Mount Sinai Harbor were the same. Sadove, in fact, stayed with one turtle for a week: its nights were invariably regular — no movement, except to surface for air. "This behavior," Sadove wrote, tiptoeing carefully, "suggested that these turtles may rest at night."

The cold-stunning episode of 1985 was followed by similar incidents in 1986 and 1987, and researchers — well aware of the abyss the species was perched upon and the potential effect such mass mortality could have — were beginning to fear a pattern. They knew there was a virtual absence in the scientific record of cold-stunning episodes in the past. From Okeanos’s beginning in 1979, for example, through 1984, Sadove had come upon only one dead ridley. And that turtle had ingested such a massive dose of cadmium that the circumstances of its death could not definitely be tied to cold-stunning. Looking back, the scientists at Okeanos hoped that the absence indicated not that few people were seeking and finding dead sea turtles on beaches but rather that dead sea turtles on beaches were rare finds.

Then, as if to justify the circumspection of scientists afraid of going out on a limb, 1988 arrived. The volunteer army of beachcombers tripled to one hundred and thirty. And the number of stranded sea turtles plummeted.

The first, most obvious theory was that sea turtles had abandoned the region: their appearance since 1985 was an anomaly, the explanation went, and the conditions that had caused them to inhabit the area in the first place — whatever those conditions may have been — had vanished. But a quick review of records disproved that. The drop had nothing to do with the number of turtles in the area. Steve Morreale, who in the late 1980s was hired as Okeanos’s director of sea turtle research (allowing Sadove to return to studying whales), told me that in the summer of 1987 Okeanos tagged and released twenty-one ridleys and loggerheads; later that year, forty two were found cold-stunned. In the summer of 1988 Okeanos again tagged and released twenty-one turtles. But that year only one turtle was found cold-stunned, and that was not on the Sound at all, but on a beach at the eastern end of Long Island’s south shore.

So if the turtle population had not declined, Okeanos’s researchers need to find another explanation for the surprising — though fortunate — lack of dead ridleys.
They checked the water temperature, so crucial to cold-blooded animals. Ridleys first arrive in the Sound — or at least they are first seen in the Sound — in August, when the water temperature has risen to almost seventy degrees Fahrenheit or higher. Water temperatures of forty-five degrees or lower are lethal, so before the water drops to that level — in November — the turtles obviously have to move back out into the Gulf Stream. Okeanos found nothing to indicate that water temperature had dropped faster than normal, or further than normal, in the years before 1988. In fact, temperatures in 1988 were slightly colder than in previous years.

A more pronounced difference was found in wind direction. In 1985, the researchers discovered, prevailing winds from the west were only slightly more common than east winds — the ratio was 1.6 to 1. But in 1988, east winds were far less common: West winds prevailed by nearly 7 to 1. As the westerlies increased, the number of strandings fell. How would that have affected sea turtles? Two possible explanations stand out. For one, the turtles may have sensed that prevailing west winds indicated the coming of winter. Because east winds were almost as common as westerlies, the animals did not recognize winter’s onset, and so they stayed put. Or, perhaps more likely, the west winds may have given the turtles a boost, helping them swim east toward the Atlantic and the Gulf Stream.

That, possibly, solved the riddle of the strandings. But the scientists at Okeanos had much more to learn about the ridleys themselves. For one thing, they wanted to know what the turtles were doing and how well they were doing in Long Island Sound. The beginning of an answer to that question was found in their food.

In the late 1980s, Morreale and Vinny Burke studied seventeen turtles and learned that they ate only bottom-dwelling invertebrates, especially spider crabs and green crabs, which constituted three-quarters of their food. The two crabs are common in the Sound and the Peconic bays, and the ridleys were having little trouble homing in on them. "There’s no question, I don’t think, about that," Burke told me. "The turtles are growing at tremendous rates," adding up to fifteen percent of their body weight in a week.

Convinced that the ridleys were thriving, Morreale and Burke next speculated about why the turtles moved inshore in the first place. The answer, Burke said, may be that very small turtles are creatures of the ocean, and in particular of the Gulf Stream, where they feed on tiny planktonic animals. The plankton is sufficiently nutritious to fuel the ridleys growth only to a certain size, after which they need bigger portions. It so happens that the bigger portions - spider crabs and green crabs - live and feed along the mussel beds that pave the bottom of the relatively shallow coastal waters, including the Sound. So, the theory goes, the ridleys sense the need for different food and instinctively know where to find it.

The answer to the next question Morreale and Burke posed - what are the critical habitats or resources for these animals? - was relatively easy.

"Wherever there are spider crabs and green crabs could be a critical habitat," Burke said. "If there are spider crabs and green crabs then there’s every reason to believe that there are sea turtles there."

Morreale said Okeanos has determined almost without doubt that the Sound and the eastern bays of Long Island "are very significant" turtle habitat.

"We find as many of that size turtle as they find in the Gulf of Mexico," he said. "A better interpretation is there are two major areas for this size turtle in the world — the Gulf of Mexico and Long Island."

He and Burke also believe that the ridleys’ domain extends far west, to the crowded and polluted waters off Fairfield County, Connecticut, and New York’s Westchester and Nassau counties. Most of their live captures come from the eastern waters because that is where they conduct most of their research. But in the big cold-stunning years, many recoveries were made in the western end of the Sound. And in 1987 Morreale fastened a transmitter to a ridley and chased it for one hundred twenty five days as it navigated west to within five miles of Throgs Neck. Said Morreale, "They’re utilizing the whole Sound, up and down."

But Okeanos’s work, as exciting and as significant as it is, still has not answered two critical questions about the Kemp’s ridley.

Why all of a sudden were so many ridleys encountered in Long Island Sound? For despite the historical records of ridleys being the most common sea turtles in New York waters, occurences of ridleys in the Sound in the years just prior to 1985 were notable for their rarity. Perhaps, as Larry Ogren, of the National Marine Fisheries Service, had speculated about the ridleys he began seeing along the Gulf Coast in 1985, the Sound’s turtles are those that were able to hatch successfully because of the protection at Rancho Nuevo. Given their small size and young age, it is almost certain that they are.

A bigger question, one asked by Sam Sadove in 1987 and still not answered by Morreale and Burke in 1990, is whether the ridleys will return to the breeding population. Archie Carr believed that some of the ridleys that reach the Atlantic — if not specifically the Sound — return to Rancho Nuevo, although his colleague Henry Hildebrand believes that the breeding turtles spend their lives within the Gulf of Mexico. Sadove told me he thinks it’s likely the Sound’s ridleys do return to reproduce because, given the small number of nesting females, it would be disastrous for a species to give up so many potential breeders. But that is the educated guess of a wildlife biologist, nothing more.

The fact is, no one has ever seen a ridley leave the Sound. The most that can be said, according to Burke, is that when turtles are caught or followed in October, they are moving east, toward The Race. And until it can be determined, either by observation or the return of a flipper tag, that they leave New York’s waters alive, opinions about whether they return to Rancho Nuevo to nest are only speculation. "We’re still waiting for that magic movement record," Ogren said.

The record may still be years away, because the Sound’s ridleys may still be years away from sexual maturity. If so, the researchers at Okeanos hope the flipper tags remain fastened until the ridleys struggle out of the Mexican surf onto the beach at Rancho Nuevo. The first time that happens would be the proof that Long Island Sound is not merely some pleasant way-station en route to the ridleys’ certain doom.

Most of the sources for this are mentioned in the text; some material came from a paper written by Burke and Morreale, which I can’t find at the moment. When I do, I’ll cite it.

3 comments:

Anonymous said...

Who knows where to download XRumer 5.0 Palladium?
Help, please. All recommend this program to effectively advertise on the Internet, this is the best program!

news games said...

I realy hope that Long Island Sound will not be ridleys’ doom :|

Anonymous said...

Hello! I'm an undergrad student writing a paper about Kemp's ridleys and I came across your paper entitled "The Kemp's Ridley Puzzle" from '87. However, I cannot seem to gain access to this article. It seems like papers about the Kemp's ridley life cycle are very scarce and I would like to read your paper. Is there a way I can access it? Thank you! My email is kdille2@tigers.lsu.edu .