Green sea turtle nests could beat record highs on the Space Coast this season. Here’s why. – via Herp Digest

By Adelaidee Chen  and Lisa Maria Garza

Orlando Sentinel, 6/21/19

The number of green turtle nests on the Atlantic coast have been on the upswing, surpassing the loggerhead turtle. Scientists are thrilled by this development.

During this time of year, sea turtles emerge from the ocean to lay eggs on the sand at night on Florida’s beaches.

The state accounts for 90 percent of the nation’s loggerhead nests, but another species also listed as threatened, the green turtle, has blown past the loggerhead on the Space Coast and is expected to post another record number of nests this year.

“So, this season is particularly exciting because this is the 'up’ year for green turtle nests,” said Ashley Lord, interpretative park ranger who leads turtle tours at Canaveral National Seashore.

Since Canaveral began protecting turtle nests from animal predators with metal screens in 1984, the female hatchlings that survived are now of reproductive age, returning to the beaches where they were hatched. There is also no light pollution and no housing development along 24 miles of beach.

During the last reproduction year for green turtles in 2017, the species surpassed loggerhead nests at Canaveral National Seashore. There were 7,736 green turtle nests to 4,556 loggerhead nests even though many of the green turtle nests later in the season were wiped out by Hurricane Irma.

Green turtles reproduce every other year. The nest screening program started in 1984, and the hatchlings that survived at higher rates would have returned to the same beaches 25-30 years later. Leatherback turtles also nest at Canaveral but result in fewer than 35 nests a year.

Female green turtles reproduce every other year and so far point-in-time counts for 2019 are higher compared to the same week in 2017 for Canaveral National Seashore as well as the nearby Archie Carr National Wildlife Refuge.

Turtle nests face obstacles in addition to hurricanes.

Last year, 1,000 nests were wiped out at Canaveral National Seashore due to predators including raccoons and feral hogs, said Kristen Kneifl, chief of resource management. So far this season, the raccoons got into about 250 nests. Canaveral has taken steps to eradicate the problem raccoons.

To protect turtles from prey, volunteers and a team of four biological technicians cover nests with 4-by-4-foot metal wire screens with holes large enough for hatchlings to crawl out of as they emerge into the world. The screens are anchored into the sand with pieces of bent rebar.

“Our numbers are getting more than our staff can handle on every given day,” Kneifl said. “They’ve got to place the screen. They’ve got to pound the rebar. And with over 100 nests a day, it’s too much.”

Volunteer Patty Lillie of Winter Park spent many years alongside staffers, locating nests at Canaveral National Seashore, riding in an all-terrain vehicle under the moonlight.

“It’s a workout — the most I’ve ever done is 28 [nests] in one night and I was toast," she said.

These days, she guides small groups at night so they can see loggerheads lay eggs.

“I love doing that part, too,” Lillie said of the tours, “because the more people experience something with an animal, the more they’re going to care about that animal.”

Visitors aren’t allowed to view green turtles laying eggs along Florida’s shorelines because it is not a permitted activity by the Florida Fish and Wildlife Conservation Commission. But scientists see them.

“To have a day when there are more green turtles nesting than loggerheads is very surprising because they were doing poorly for so long,” said Jane Provancha, an ecologist who has studied Florida’s sea turtles extensively.

But as the climate gets warmer, there is concern there won’t be enough male sea turtles to sustain long-term population growth. The warmer the sand temperature, the more likely the hatchling will be a female.

It’s a subject Provancha researched in the late 1980s with the late Nicholas Mrosovsky. They discovered that loggerhead hatchlings from 1986-1990 at Cape Canaveral Air Force Base were more than 90 percent female. Green turtles develop similarly to loggerheads, she said. Their differences can be found in migratory patterns and diet, among other factors.

“We believe there are more females to start off in the ocean when animals are released from their nest," she said, but experts still don’t know a lot about the gender ratio in the adult stage because the males tend to stay in the water while the females show up on the beach.

In Australia, she said, studies have estimated the gender ratio of turtles in the water is two or three females to one male.

“We could assume the same” for the Atlantic population, she said.

Warmer sand temperatures can also speed up when the eggs will hatch. They also can cause sea turtles to lay their eggs further north where it might be cooler, although green turtles will nest within five to 10 miles of where they were born. Loggerheads seem to nest within a 40-mile range.

Atlantic green turtles were listed as endangered only as recently as 2016, when they were downgraded to threatened under the Endangered Species Act. Loggerheads in this area also are listed as threatened.

The idea that there would be this many green turtles today couldn’t have been predicted 15, 20 or 30 years ago, Provancha said.

Sea turtle survey shows the endangered animals are making a comeback – via Herp Digest

Hunting bans and other conservation efforts may be paying off — though warming oceans remain a serious threat.Sea turtle survey shows the endangered animals are making a comeback.

May 1, 2019, by Jaclyn Jeffrey- Wilensky, NBCNews.com

A new survey of sea life in the Pacific Ocean suggests that some endangered sea turtles are making a comeback. The survey showed that populations of green sea turtles along dozens of coral reefs in waters around Hawaii and other nearby regions either remained stable or increased from 2002 to 2015.

The scientists behind the survey, which was described April 24 in the journal Plos One, called the finding compelling evidence that conservation efforts like hunting bans are working.

“You often hear such bad and challenging news about the threats that our ocean faces,” said Kyle Van Houtan, chief scientist at the Monterey Bay Aquarium in Monterey, California, and leader of the team of researchers that conducted the survey. “There are places where there are a lot of sea turtles very close to shore. And that’s good news.”

Once hunted for their meat, green sea turtles were designated an endangered species in 1978. They're now protected under U.S. law and international treaties.

The same survey suggested that populations of hawksbill turtles, another protected species that is even more endangered, remain perilously low.

The survey effort began almost by accident, according to Van Houtan. On a research expedition to count fish living on reefs, divers with the National Oceanic and Atmospheric Administration found themselves counting turtles, too.

As it turns out, counting turtles in the water is more reliable than counting them on land, where only egg-laying females and their hatchlings are visible. “Really understanding the dynamics of turtle populations requires more attention to different age classes, and that means getting out on the water,” David Godfrey, executive director of the Sea Turtle Conservancy in Gainesville, Florida, told NBC News MACH in an email.

So Van Houtan and his colleagues decided to formalize the count. Over 13 years, divers trained to count green sea turtles and hawksbills visited 53 reefs across the Pacific, including spots in Hawaii, the Marshall Islands and American Samoa. Towed along by a slow-moving boat for a total of more than 4,500 miles, the researchers tallied more than 3,400 turtles.

The research represented a “Herculean effort,” Van Houtan said, adding, “This is the kind of data and the kind of study we’ve wanted for so long.”

Analysis showed that what the scientists call "turtle density" — the estimated number of animals per kilometer based on the survey counts — had increased by as much as 8 percent each year in some areas.

Turtle density increased the most in areas that tended to have few turtles at the start of the census period, including the Hawaiian Islands. The greatest turtle density was seen In the Pacific Remote Island Areas, uninhabited islands west of Hawaii, with an average of 3.62 green turtles per kilometer.

Hawksbill turtles, meanwhile, were outnumbered by green turtles by 11 to 1. “Their numbers have not really come back,” Van Houtan said of the hawksbills.

The highest turtle densities were seen in regions with plenty of seagrass and algae for the turtles to eat; minimal human presence; and, most important, water temperatures at 80 to 82 degrees Fahrenheit. Sea turtles flourish in that "Goldilocks" environment, which is neither too hot nor too cold.

But as the world's climate continues to warm, turtles and other marine species may be forced to relocate. “As the ocean warms with climate change, that ideal temperature is going to move toward the poles and away from the equator,” Van Houtan said. “As the temperatures change, those distributions are going to change.”

While Van Houten is wary of the effects this move will have on the greater coral reef ecosystem, he’s optimistic about the turtles’ odds for survival.

“They’re very resilient animals, and they’ve lived for millions of years,” he said. “The turtles aren’t going to roll over and die.”

How to Stop Sex Changes in Turtles on the Great Barrier Reef-Climate change led to more female eggs, so scientists are trying to ensure males are made in the shade - via Herp Digest

by Anita Rita Patricia, The Conversation US, 1/17/18

                       

Credit: Alaina McDavid Flickr (CC BY-SA 2.0)

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research.

In the northern part of Australia’s Great Barrier Reef, the future for green sea turtles appears to be turning female.

A recent study has revealed that climate change is rapidly leading to the feminisation of green turtles in one of the world’s largest populations. Only about 1% of these juvenile turtles are hatching male.

Among sea turtles, incubation temperatures above 29ºC produce more female offspring. When incubation temperatures approach 33ºC, 100% of the offspring are female. Cooler temperatures yield more males, up to 100% near a lower thermal limit of 23ºC. And if eggs incubate at temperatures outside the range of 23-33ºC the risk of embryo malformation and mortality becomes very high.

As current climate change models foresee increases in average global temperature of 2 to 3ºC by 2100, the future for these turtles is in danger. Worryingly, warmer temperatures will also lead to ocean expansion and sea-level rise, increasing the risk of flooding of nesting habitats.

HOW SCIENTISTS ARE TACKLING THE PROBLEM

Green sea turtles’ sensitivity to incubation temperatures is such that even a few degrees can dramatically change the sex ratio of hatchlings.

Sea turtles are particularly vulnerable because they have temperature-dependent sex determination, or TSD, meaning that the sex of the offspring depends on the incubation temperature of the eggs. This is the same mechanism that determines the sex of several other reptile species, such as the crocodilians, many lizards and freshwater turtles.

Scientists and conservationists are well aware of how future temperatures may threaten these species. For the past two decades they have been investigating the incubation conditions and resulting sex ratios at several sea turtle nesting beaches worldwide.

This is mostly done using temperature recording devices (roughly the size of an egg). These are placed inside nest chambers among the clutch of eggs, or buried in the sand at the same depth as the eggs. When a clutch hatches (after 50 to 60 days) the device is recovered and the temperatures recorded are analysed.

Research has revealed that most nesting beaches studied to date have sand temperatures that favour female hatchling production. But this female bias is not immediately a bad thing, because male sea turtles can mate with several females (polygyny). So having more females actually enhances the reproductive potential of a population (i.e. more females equals more eggs).

But given that climate change will likely soon increase this female bias, important questions arise. How much of a female bias is OK? Will there be enough males? What is the minimum proportion of males to keep a sustainable population?

These questions are being investigated. But, in the meantime, alarming reports of populations with more than 99% of hatchlings being female stress the urgency of science-based management strategies. These strategies must be designed to promote (or maintain) cooler incubation temperatures at key nesting beaches to prevent population decline or even extinction.

THE CHALLENGE OF REVERSING FEMINISATION

There are two general approaches to the problem:

            1          mitigate impacts at the most endangered nesting beaches

            2          identify and protect sites that naturally produce higher proportions of males.

Several studies emphasise that the natural shading native vegetation provides is essential to maintain cooler incubation temperatures. Thus, a key conservation action is to protect beach vegetation, or reforest nesting beaches.

Coastal vegetation also protects the nesting beach against wave erosion during storms, which will worsen under climate change. This strategy further requires coastal development to allow for buffer zones. Construction setback regulations should be enforced or implemented.

When natural shading is not an option, clutches of eggs can be moved either to more suitable beaches, or to hatcheries with artificial shading. Researchers have tested the use of synthetic shade cloth and found it is effective in reducing sand and nest temperatures.

Other potential strategies involve adding light-coloured sand on top of nests. This can help by absorbing less solar radiation (heat) compared to darker sand. Beach sprinklers have also been tested to simulate the cooling effect of rainfall.

The effectiveness of these actions has yet to be fully tested, but there is concern about some potential negative side effects. For example, excess water from sprinklers may cause fungal infections on eggs.

Finally, as much as mitigation measures are important, these are always short-term solutions. In the long run, prevention is always the best strategy, i.e. protecting the nesting beaches that currently produce more males from deforestation, development and habitat degradation.

Our recent research on the largest green turtle population in Africa reports unusually high male hatchling production. We found almost balanced hatchling sex ratios (1 female to 1.2 males). We attributed this mostly to the cooling effect of the native forest.

This, and similar nesting beaches, should be designated as priority conservation sites, as they will be key to ensuring the future of sea turtles under projected global warming scenarios.

Sea turtles are resilient creatures. They have been around for over 200 million years, surviving the mass extinction that included the dinosaurs, and enduring dramatic climatic changes in the past.

There is potential for these creatures to adapt, as they did before. This could be through, for example, shifting the timing of nesting to cooler periods, changing their distribution to more suitable habitats, or evolution of critical incubation temperatures that produce males.

But the climate today is changing at an unprecedented rate. Along with the feminisation of these turtles in the northern Great Barrier Reef, sea turtles globally face many threats from humans. These include problems associated with by-catch, poaching, habitat degradation and coastal development, plus a history of intense human exploitation.

In 2018, the prevalence of these species depends now more than ever on the effectiveness of conservation measures.

Herpes Outbreak Among Australia’s Green Sea Turtles Likely Triggered by Pollution – via Herp Digest

From Gizmodo, 7/5/16 by George Dvorsky

Australian scientists in the midst of investigating a herpes outbreak among green sea turtles at the Great Barrier Reef say the blight—which causes abnormal growths on the skin, mouth, eyes, and internal organs—is likely due to pollution. 

For the past three years, Karina Jones from James Cook University in Townsville, Australia, has been investigating fibropapillomatosis (FP) among green sea turtles in the Great Barrier Reef. This condition, triggered by a turtle-specific herpes virus, causes disfiguring tumors around the eyes armpits, genitals, neck and flippers. The tumors are benign, but they can often lead to death, as the growths can obstruct a turtle’s vision and prevent them from finding food or avoiding predators and boats. It also makes them more vulnerable to further infections.

Scientists aren’t sure how or why sea turtles get the disease, or why it’s starting to spread like wildfire. Indeed, other parts of the world are recording similar outbreaks, including Florida and Hawaii. Forty years ago, FP was seen in about 28 to 67 percent of sea turtles. Today, it’s as high as 92 percent in certain regions, and it’s most prominent in warmer climates.

As New Scientist now reports, an unpublished survey by Jones’ team shows that rates of the herpes virus is most pronounced along a specific stretch of water at Magnetic Island, which happens to be a popular tourist attraction at the reef. The team’s research shows that about half of the turtles in these waters have FP, compared to 10 percent elsewhere around Cockle Bay.

This new research bolsters the suggestion that a connection exists between FP and human activity. Previous research has shown a strong correlation between near-shore habitats and the disease.

Importantly, this virus exists around the world, and many turtles carry the virus—but it’s often dormant. “We think there must be some external trigger that causes the tumor development,” noted Jones in New Scientist. That “external trigger” is likely pollution, but these researchers aren’t sure which contaminants are responsible. Looking ahead, her team plans to evaluate historical water quality data and test water samples for chemicals like heavy metals, pesticides, and fertilizer. The researchers will also collect blood samples and swabs from turtles to find out what’s going on at a physiological level.

It’s a daunting task, but this work is hugely important. Green sea turtles are classified as an endangered species, currently threatened by over harvesting of their eggs, hunting of adults, fishing gear, and a loss of nesting beach sites. They don’t need another enemy.

Baby Turtles Mysteriously Dying on Australian Island

By Kacey Deamer, Staff Writer | July 7, 2016 07:08am ET

There may be such a thing as too many turtles, according to scientists investigating why so few turtle eggs were hatching on Raine Island, located on the tip of Australiaꞌs Great Barrier Reef.

For more than 1,000 years, green sea turtles have nested on Raine Island, where they dig pits to lay and bury their developing eggs. Yet after a millennia of fruitful nesting seasons, the island has recently had a drop in the rate of successful hatches — now less than 30 percent, even in undisturbed nests.

With protective coral along the broad sandy beaches, and no land-based predators, scientists were stumped as to why an otherwise ideal nesting location would have so few baby turtles hatching from eggs and scuttling down to the water.

Seawater was the first suspect. Scientists thought flooding of the nests during high tides was killing newly laid eggs, which cannot survive underwater. Sand was added to a section of the beach in 2014, raising it by 3 to 5 feet (1 to 1.5 meters), but hatching rates were still extremely low. Then in 2015, hatching success doubled, leaving scientists to question what had changed.

A new theory from researcher David Booth of the University of Queensland suggests that the island's popularity for nesting is to blame for the plunge in hatching success.

Fewer turtles laid nests on the island in 2015, Booth said in a statement. That bit of information suggested that "a density-depending effect was limiting hatching rates even in nests that remained undisturbed throughout incubation, rather than the environmental conditions."

Continued ...

Green Sea Turtles Are No Longer Endangered in Florida and Mexico – via Herp Digest

Decades of conservation efforts have led authorities to downgrade the turtles to threatened, though many challenges still remain

by Jason Daley, Smithsonian.com ,April 6, 2016

The last century have been brutal for sea turtles of all species. Beach developments destroyed nesting sites for the giant marine reptiles, pollution and warming waters made them ill, fishing nets snared them, and industrial-scale harvesting to feed people crashed their populations. But there is finally some good news when it comes to sea turtles. Yesterday, NOAA Fisheries and the U.S. Fish & Wildlife Service announced they’ve downgraded populations of the green sea turtle, Chelonia mydas, in Florida and Mexico from endangered to threatened.

It’s an incremental victory for the turtles, which were still being made into canned soup in the Florida Keys as late as the early 1970s. But since they were listed as endangered in 1978, the breeding populations in Florida and Mexico have rebounded due to protection of nesting grounds, prohibitions on catching the turtles, and efforts to reduce “bycatch,” when turtles get caught in fishing nets. According to NOAA, the breeding population in Florida has increased from just a handful in the late 1970s to 2,250 nesting females during the last census.

The agencies also announced a new plan to help recover green sea turtles worldwide. They are dividing the global turtle habitat into 11 sections, which allows conservationists to implement various management plans. In eight of those sections the turtles are listed as threatened. According to Discovery News, the turtles will be listed as endangered in the Mediterranean, Central South Pacific and Central West Pacific Ocean.

“Successful conservation and management efforts developed in Florida and along the Pacific coast of Mexico are a roadmap for further recovery strategies of green turtle populations around the world,” Eileen Sobeck, assistant NOAA administrator for fisheries says in the press release.

Still, there are many challenges for the almost 600,000 nesting female green sea turtles around the world. Fishing nets remain an issue, as are egg poachers in some areas. A viral disease called fibropapillomatosis leads to tumors in some young turtles in warm waters. And rising sea levels may affect nesting habitat.  With so many challenges remaining for the green sea turtles, tailoring the management strategies to small groups will help them target the specific issues each population faces, Sobeck explains in the release.

“Florida's coasts are ground zero for sea-level rise,” Jacki Lopez, Florida director for the Center for Biological Diversity tells Jenny Staletovich at The Miami Herald, “and the country is looking for us to carefully plan and manage for rising seas and our nesting sea turtles.”

Even so, the news is welcome in the grim world of ocean conservation. “The undeniable recovery of most green sea turtle populations creates a hopeful spot in our changing oceans,” Catherine Kilduff an attorney with the Center for Biological Diversity’s oceans program says in a press release. “This success story shows that the Endangered Species Act works and is an essential safety net for endangered wildlife.”

Rare green sea turtles have overpopulated the Indonesia's Derawan Island

GREEN sea turtles remain a rare sight in many parts of the world, but one Indonesian island tasked with protecting them is being overrun by far too many.

New research suggests that the gentle endangered creatures are crowding into a marine reserve in numbers never recorded anywhere, gobbling seagrass to the point that they risk destroying the food source that's vital to their survival.

Up to 20 turtles were spotted in an area covering about one hectare at Derawan Island off Indonesia's part of Borneo in 2011. That means snorkelers are almost guaranteed to see a turtle every moment they're in the water. The rate was four times higher than non-protected areas elsewhere and also topped historic numbers reported before the reptile was hunted by humans.

Read on

Tortuga Rising- A conservation success story - via Herp Digest

Published in the May/June 2013 issue of Orion magazine by — Andrew D. Blechman 

ALTHOUGH GREEN SEA TURTLES have inhabited the Pacific coast of Mexico for millions of years, for the past few decades these ancient mariners (known locally as tortugas prietas or “black turtles”) have struggled to survive a relentless onslaught of hunting. As recently as the early 1980s, there were still some twenty-five thousand of their nests each year along the Mexican coast. But as demand grew for turtle meat and eggs in Mexico and across the U.S. border, turtle hunting multiplied exponentially. When the Mexican government outlawed the trafficking of sea turtles in 1990, turtle hunters were labeled poachers and smugglers overnight, but the practice continued. By the mid-1990s, poaching, fishing nets, and habitat pollution and destruction had caused the number of nesting females to drop to less than five hundred.

It was at this time that a doctoral student named Wallace J. Nichols proposed studying the biology and conservation of sea turtles in northwestern Mexico for his thesis, but was told that cultural inertia was too great to overcome and it was too late to even bother trying. Undeterred, Nichols and a colleague traveled to Baja California to study the five species of sea turtle that congregate on both sides of the peninsula’s nineteen hundred miles of coastline to feast on crab, jellyfish, sea sponges, and algae.

With the help of a fisherman and a Mexican biologist, Nichols attached a transmitter to a captured loggerhead’s shell. The turtle, named Adelita after the fisherman’s daughter, swam seven thousand miles from Baja California to nesting grounds in Japan, marking the first time any animal had been tracked swimming across an ocean. The experience convinced Nichols that the best way to change cultural habits was to earn the trust and respect of a local population, rather than alienate them through guilt and reams of scientific data.

“These turtles are big, strong, and wild—yet gentle,” Nichols says of these 150-pound sea creatures. “And you can get close to them and interact with them. There aren’t many creatures that big that you can do that with in the wild, and on their own terms. My goal was to share that sense of wonder; not to preach.” So Nichols invited dozens of turtle-hunting fishermen to a meeting to talk about their knowledge of local turtles and the possibility of their extinction. In time, many of the poachers agreed to catch and eat fewer turtles—which are traditionally prized for their red-meat-like flesh—and soon began working with Nichols to monitor local turtle populations and collect data.

Twenty years later, Grupo Tortuguero, the grassroots network that Nichols helped found, is active in fifty coastal communities. Hundreds of local volunteers, many of whom are former poachers, work to protect and promote an appreciation for and pride in these gentle animals. Says Nichols, “If given the chance, who wouldn’t want the opportunity to tell their grandkids that they helped rescue from extinction an animal that’s so central to their culture?”

This year there were some fifteen thousand green sea turtle nests on the beaches of southern Mexico. Also 4 1/2 minute video at http://www.orionmagazine.org/index.php/articles/article/7486/

Hypothermic sea turtles rescued on Cape Cod (Loggerhead and Green Sea Turtles) – via Herp Digest

By Sarah N. Mattero, Boston Globe Correspondent, 11/27/12

Forty hypothermic sea turtles found on Cape Cod are being taken to the New England Aquarium’s care center in Quincy to be warmed up, the aquarium said today.

The endangered reptiles, mostly large loggerheads and green sea turtles, have been pouring in over the past three days, aquarium spokesman Tony LaCasse said in a statement.

Sea turtles often become stranded from early November through December, so volunteers from the Massachusetts Audubon Sanctuary at Wellfleet Bay stake out the coasts each year in order to save them.

Despite the fact that sea turtles are cold-blooded, they are susceptible to infections at such low body temperatures. The aquarium takes the reptiles and warms them up 5 degrees a day until their body temperature reaches slightly more than 70 degrees.

Almost 90 sea turtles have been rescued so far this season, including the recent batch, the aquarium said.

Loggerhead turtles are both an endangered and threatened species and typically weigh up to 250 pounds and grow up to 3 feet long, according to the National Oceanic and Atmospheric Administration. Green sea turtles are also an endangered and threatened species and can grow to about 3 feet long and weigh more than 300 pounds.