Oh noes! Models say that climate change, ENSO, and beach sand heat will kill sea turtles

From the busy BEES at Drexel University, worry that beach sand temperature 40 to 50 centimeters deep will be affected by the global warming air temperature rise of 0.8C over the last century, projected to increase. The models identified this as the leading projected cause of climate-related decline in leatherback turtles. They say “if actual climate patterns follow projections in the study, the eastern Pacific population of leatherback turtles will decline by 75 percent by the year 2100.” Gosh.

But they write in their press release as if the projections are actually happening:

Leatherback turtles, Spotila says, are in critical need of human help to survive. “Warming climate is killing eggs and hatchlings,” Spotila said. “Action is needed, both to mitigate this effect and, ultimately, to reverse it to avoid extinction. We need to change fishing practices that kill turtles at sea, intervene to cool the beach to save the developing eggs and find a way to stop global warming. Otherwise, the leatherback and many other species will be lost.”

It makes you wonder how the turtles ever survived the Roman Warm Period or the Medieval Warm Period or the early part of the Holocene?

Caption: A leatherback sea turtle hatchling crawls across the beach toward the ocean. Heat-related deaths of turtle eggs and hatchlings in nests before they emerge and enter life at sea was identified as the leading projected cause of climate-related decline in leatherback turtles in the eastern Pacific in a new study. The study suggests that climate change could exacerbate existing threats that have already made leatherbacks critically endangered, and nearly wipe out the eastern Pacific population in the 21st century. The study, by a research team from Drexel University, Princeton University, other institutions and agencies, is published online in Nature Climate Change on July 1, 2012.
Credit: Jolene Bertoldi / ZA Photos, via Flickr

Rising heat at the beach threatens largest sea turtles, climate change models show

PHILADELPHIA (July 1, 2012)—For eastern Pacific populations of leatherback turtles, the 21st century could be the last. New research suggests that climate change could exacerbate existing threats and nearly wipe out the population. Deaths of turtle eggs and hatchlings in nests buried at hotter, drier beaches are the leading projected cause of the potential climate-related decline, according to a new study in the journal Nature Climate Change by a research team from Drexel University, Princeton University, other institutions and government agencies.

Leatherbacks, the largest sea turtle species, are among the most critically endangered due to a combination of historical and ongoing threats including egg poaching at nesting beaches and juvenile and adult turtles being caught in fishing operations. The new research on climate dynamics suggests that climate change could impede this population’s ability to recover. If actual climate patterns follow projections in the study, the eastern Pacific population of leatherback turtles will decline by 75 percent by the year 2100.

Modeling the Ebb and Flow of Turtle Hatching with Climate Variation

“We used three models of this leatherback population to construct a climate-forced population dynamics model. Two parts were based on the population’s observed sensitivity to the nesting beach climate and one part was based on its sensitivity to the ocean climate,” said the study’s lead author Dr. Vincent Saba, a research fishery biologist with the NOAA National Marine Fisheries Service Northeast Fisheries Science Center, visiting research collaborator at Princeton University, and a Drexel University alumnus.

Leatherback turtle births naturally ebb and flow from year to year in response to climate variations, with more hatchlings, and rare pulses of male hatchlings, entering the eastern Pacific Ocean in cooler, rainier years. Female turtles are more likely to return to nesting beaches in Costa Rica to lay eggs in years when they have more jellyfish to eat, and jellyfish in the eastern Pacific are likely more abundant during cooler seasons. Turtle eggs and hatchlings are also more likely to survive in these cooler, rainier seasons associated with the La Niña climate phase, as this research team recently reported in the journal PLoS ONE. In addition, temperature inside the nest affects turtles’ sex ratio, with most male hatchlings emerging during cooler, rainier seasons to join the predominantly-female turtle population.

The researchers applied Saba’s combined model of these population dynamics to seven climate model projections assessed by the Intergovernmental Panel on Climate Change (IPCC). The climate model projections were chosen based on their ability to model El Niño Southern Oscillation (ENSO) patterns on the temperature and precipitation in the region of Costa Rica where this team has conducted long-term leatherback studies.

Hot Beaches, More Warm Years Threaten Turtles’ Recovery

The resulting projections indicate that warmer, drier years will become increasingly frequent in Central America throughout this century. High egg and hatchling mortality associated with warmer, drier beach conditions was the most significant cause of the projected climate-related population decline: This nesting population of leatherbacks could decline by 7 percent per decade, or 75 percent overall by the year 2100.

The population is already critically low.

“In 1990, there were 1,500 turtles nesting on the Playa Grande beach,” said Dr. James Spotila, the Betz Chair Professor of Environmental Science in the College of Arts and Sciences at Drexel. “Now, there are 30 to 40 nesting females per season.”

Spotila, a co-author of the study, has been studying leatherback turtles at Playa Grande in Costa Rica, the largest leatherback nesting beach in the eastern Pacific, with colleagues and Drexel students, for 22 years.

Poaching of turtle eggs was a major cause of the initial decline, and was once such a widespread problem that virtually no turtle hatchlings would survive at Playa Grande. Spotila and colleagues worked with the local authorities in Costa Rica to protect the leatherbacks’ nesting beaches so that turtle nests can hatch in safety. By catch of juvenile and adult turtles in fishing operations in the eastern Pacific remains a threat.

For the population to recover successfully, Spotila said, “the challenge is to produce as many good hatchlings as possible. That requires us to be hands-on and manipulate the beach to make sure that happens.”

Spotila’s research team is already investigating methods such as watering and shading turtle nests that could mitigate the impact of hot, dry beach conditions on hatching success.

###

Link to this Nature Climate Change study: http://dx.doi.org/10.1038/NCLIMATE1582

Link to recent news release about a related study by this research team in PLoS ONE: http://www.drexel.edu/now/news-media/releases/archive/2012/May/El-Nino-Climate-Change-Threaten-Leatherback-Sea-Turtles/

============================================================

Maybe this is a bigger problem? From Wikipedia:

Asian exploitation of turtle nests has been cited as the most significant factor for the species’ global population decline. In Southeast Asia, egg harvesting in countries such as Thailand and Malaysia has led to a near-total collapse of local nesting populations.[62] In Malaysia, where the turtle is practically locally extinct, the eggs are considered a delicacy.[63] In the Caribbean, some cultures consider the eggs to be aphrodisiacs.

 

Advertisements

  Subscribe  
newest oldest most voted
Notify of
Warren in New Zealand

“We used three models of this leatherback population to construct a climate-forced population dynamics model.
It’s turtles all the way down then

I watched giant turtles on a beach in Masira Island, Oman, dig their egg holes, lay about 100 eggs, fill in the hole and struggle back to the sea and all digging done with their back flippers. I even watched the young by the hundred dig themselves out of their holes and aim for the sea. All this at temperatures higher than those leatherbacks endure.
These conservationists forget that extinction is the ultimate fate of all species.

Wijnand

“We need to change fishing practices that kill turtles at sea, intervene to cool the beach to save the developing eggs and find a way to stop global warming.”
How about those mist sprayers they use in Disney World to cool the people waiting in line for Pirates of The Carribean?

gbaikie

What part of global warming theory is suppose increase the temperature of sand?

KnR

There is still plenty of good cash in the AGW scare bucket for ‘research’ even if the political will has gone out of its sails , its still seem to be the case that no matter how poor the ‘science’ you can always get funded if you produce the ‘right results ‘ to support the ’cause’
And it its meaningless models all the way with a ton of speculation throw in and science by press release , they your merely following what is clear the standard methodology for ‘climate science’
Will the rest of the scientific establishment realize why there silence over such ‘games ‘ causes science in general to look like a joke to the people , or are their ivory towers so high they simple can’t see understand why the see no evil , hear no evil , speak no evil of your fellow ‘scientists’ no matter what they do is a bad idea ?

Gail Combs

Blaming every possible catastrophe and every “extinction” on CAGW is really getting a bit old. It also means money is wasted.
It is about time true environmentalists started shouting this crap down

Geoff Alder

The temperature of beach sand is most largely dependent on the intensity of solar radiation of the moment. Surely this should be fundamental for the folk of Drexel University. Solar radiation passes through the atmosphere at light-speed and impacts the surface of the sand. At noon on a bright and clear day that energy-exchange will pump up the temperature of the sand surface enormously. It will fry the soles of your feet. Some of that newly-acquired heat will conduct downward into the body of the sand, while the greater part will add temperature to the layer of contacting air that makes its way across the surface of the beach. It is probably largely in order to avoid getting their flippers and egg-laying apparatus scorched that turtles, in their wisdom, beach at night to conduct their egg-laying activities. Any 0,8K shift of the mean atmospheric will have no bearing worthy of mention on this overall -process. But, to have need to explain this process to the good folk of Drexel University… words fail!

My kin in Key West did more damage to the ickel turtles 100 years ago than any warmer can imagine. They hunted the suckers down and ate or sold them. Tasty too. Recipes on request.

Skeptikal

The real endangered species are the Climate Scientists. With the lack of warming, the lack of sea level rise and the lack of any credibility in their predictions… surely we’ll see them go extinct in our lifetime.

Jimbo

I thought that most of the warmiing was projected to be nearer the poles.
How ever did they cool the beaches during the holocene climate optimum? Do all the beaches where leatherback turtles lay their eggs have the same temperature? We need to dig deeper.

“In 1990, there were 1,500 turtles nesting on the Playa Grande beach,” said Dr. James Spotila, the Betz Chair Professor of Environmental Science in the College of Arts and Sciences at Drexel. “Now, there are 30 to 40 nesting females per season.”
That is, numbers have fallen by 97-98 per cent over 22 years in which temperature rise has been modest. If anyone is seriously concerned about the turtle population, possible warming by 2100 is hardly a major issue. If the issues that caused the decline are not addressed, they will be soon gone whatever the temperature.

Well we are moving beyond cuddly looking polar bears but it is still designed to be an appeal to emotion. You humans must change your behaviors because of this possibility we are modelling. I mean look at that raised head. One of the primary elementary science curricula used in the US is designed to create just this kind of emotional bonding with cute creatures. The emotions are there at an unconscious level ready to respond to an future marketing campaign on danger.
It helps that the sea turtles only tend to be seen at times few people are on the beach. And that’s the reality even when the population is healthy. The child and then the adult though are primed to believe they are not seeing sea turtles because they are already endangered. Must change behaviors NOW if anyone is to ever see a sea turtle again.
If you really want to see one, change your behavior to walking on the beach at dusk and predawn. Instead of pushing for a return to windmills.

Tom in Florida

A bigger danger to sea turtles is artificial lighting. Turtle hatchlings are attracted to light and can wander inland towards homes and street lighting instead of the sea. Coastal Florida has regulations for light abatement on beaches. Also, as with TS Debbie, coastal erosion from storms can wipe out nests.

Robert Thomson

This posting by Wills adds some proper science as to why turtles choose to lay their eggs in sand ……..they have evolved in this way because:-
Time Lags in the Climate System
Posted on June 18, 2012 in WUWT by Willis Eschenbach
Guest Post by Willis Eschenbach
Did you ever sit on a hot sand beach and dig your hand down into the sand? You don’t have to dig very far before you get to cool sand … but even though it’s nice and cool a few handwidths down, the fact that it is cool doesn’t matter at all to either the temperature of your feet or to the temperature of the air.
………………………………………………………………………………………
PS—To return one final time to the sandy beach, my natural habitat, the diffusivity of dry sand is on the order of a = 1.3E-7 m^2 per second, with t = 86400 seconds for the cycle length (one day). Using those variables in Equation 2, we find that the depth z required to get only half the temperature swing of the surface sand is only 4 centimeters, or about an inch and a half …

cartoonasaur

Soooooo….. People were EATING the turtle eggs. Year after year. The turtles were very few in number because of this. Recently, people were prevented from eating the eggs. And so the turtles have recovered a bit. BUT! Global Warming! Hot sand! Oh noes! Send money! Spread the money on the sand! Hurray! See? The sand is cool! Now the turtles are saved again!

Human predation seems to be the major cause. That we have some ability to influence. Yet, these folks seem to use the decline as an excuse for funding/publications in their field. I should be surprised?

henrythethird

“…New research SUGGESTS that climate change COULD exacerbate existing threats and NEARLY wipe out the population…”
“…NEARLY wipe out the population…” Extinction means ALL of them will be gone. They added this so that just in case one turtle makes it to Jan 1st, 2100, they’ll be right.

George E. Smith;

Well, I’ve seen experimentally recorded data that disproves their model. The very famous and scientifically and intellectually honest Jack Cousteau (late) and also his son, have filmed (or videotaped), live and very uncooked turtles being snatched off the beaches by those evil Frigate birds; by the tens of thousands. Even crabs have been coming out of those very same sand Webers, and hauling those turtles back down to where they can cook them some more.
I don’t believe Jack would ever have lied to us with photo-shopped film of something they didn’t actually see happen; or pull tricks, like killing fish to goad sharks into a feeding frenzy, so he could film it for us American saps, so we’d pay for him to have his fun.
So I say they should put a bounty on Frigate birds, and sand crabs too; it is they who (what/that) are (is) killing all the little turtles; also they should stop people from making film of it for profit.

Raybo

“The researchers applied Saba’s combined model of these population dynamics to seven climate model projections assessed by the Intergovernmental Panel on Climate Change (IPCC)”
Models? Garbage in = Garbage out. As soon as I hear the word “model” in one of these scare monger reports, all the rest is just noise.

Richard111

Okay. How long will that quote from Wikipedia remain on their site?

Steve Keohane

I wouldn’t be surprised if the turtles can tell how hot it is and adjust the depth a couple of inches to accommodate, after all the warmest part of this interglacial is long over, so they’ve had several thousand years to practice.

Ian W

As you say these turtles survived the Holocene Optimum _and_ the Eemian which was hotter. It is obvious that none of these researchers or their professors at Drexel are obviously ignorant of the evolution of turtles more than 200 million years ago.
It is worrying that a university that says “The Academy of Natural Sciences of Drexel University is America’s oldest natural history museum and a world leader in biodiversity and environmental research. For 200 years, the Academy has encouraged and cultivated the sciences, exploration of biodiversity and sharing discoveries with the public.” can display such ignorance. Perhaps they are putting too much into the Agenda21 ‘biodiversity’ meme and the ‘community outreach’ and too little into actually learning biology.

Don’t turtles dig their way down until they find sand at the right dampness and temperature? Be interesting to compare laying depths for various species at various incubating sites with ambient temperatures for the incubating season. I’m not a scientist, just saying.

ImranCan

Anyone who has had to scamper across a hot beach when they forgot their flip-flops, running from shady spot to shady spot … or digging the feet underneath …. knows more about the thermodynamic properties of sand than these chumps ever will.

Gerry Parker

Their numbers are wrong. It could be a decline of 4.72% per decade or 8.6% per year but not 3.3% or 7% per decade. No no no. My models are conclusive, and I used four of them. And no, you can’t see the data or the models. Later, I’ll model something else that might happen (but won’t).
Turtles, by the way, have no knowledge that the temperature of sand is dependent on depth. They have asbestos feet with no sensory organs.
Anyway, the surface of the sand will be hard and glassy, so they won’t be able to dig through anyway.
Tired of this yet?
Gerry

Henry Clark

the global warming air temperature rise of 0.8C over the last century
Global warming is a number of times less in the tropics than in the arctic, really more arctic warming than it is global warming. One could look up the exact figure for this location, but it had probably a trivial 0.1 to 0.3 degrees Celsius at most if like most of the tropics, like moving a few tens of miles closer to the equator under the average north-south temperature gradient.
It wouldn’t be an arctic location, as turtles, like other reptiles, do better in warmth than cold; indeed, the article mentions Costa Rica.
Global precipitation, incidentally, went up by 2% or so over the past century, as warming a mostly water-covered object (Earth) increases the amount of water going from the oceans to land rainfall, as not just land warms.
As for the claim of fewer jellyfish in warmer climates, traditionally the claim is the exact opposite, e.g. http://wattsupwiththat.com/2012/02/23/another-meme-bites-the-dust-jellyfish-and-global-warming/
But eventually one comes to observe how these guys tend to just say whatever is convenient: if jellyfish increase is considered bad, it is trumpeted as from global warming, while, if the opposite is considered bad, then decrease is claimed to also be blamed on global warming.

DJ

On the presumption that sea turtles are reptiles and their eggs need to incubate at about 80˚F, it’s a miracle they managed to survive repeated ice ages. Never mind warmer periods.
Based on the premise given for their peril, it would seem that any egg laying species should be at risk.
If man’s resulting 400PPM CO2 can prove so remarkably catastrophic, it is certainly beyond my comprehension to understand how any species survived when CO2 was higher, or when the earth was far colder. But now we know what happened to the unicorns.

David Schofield

Warren in New Zealand says:
July 2, 2012 at 3:08 am
“It’s turtles all the way down then”
nice one

Gail Combs says: July 2, 2012 at 3:36 am
“It is about time true environmentalists started shouting this crap down”
— — —
We are Gail, we are:
http://wattsupwiththat.com/2010/04/07/conservamentalism/

Steve C

Egg poaching? Fishing? This all begins to sound a bit … well, polar bearish. I suspect that, if humanity tried a bit harder to leave the leatherbacks alone, they’d do OK, as Nature intended, as the poley bears did.

David Schofield

I visited a turtle breeding beach in Turkey about 20 years ago. Tourists were allowed on the beach but told not to dig the sand and not disturb the eggs, about a foot down. Fair enough.
Amazingly most of them went and hired beach umbrellas [with the sharp point] and proceeded to ram them into the beach!
If only these academics would get out of the IT room and go and see what really goes on.

Robert of Ottawa

But .. but … but … please miss (hand in air) … won’t the rising sea level help keep the eggs cool?

Richard Briscoe

For the turtles’ sake, I really hope that well-meaning greenies don’t actually start putting sunshades up on the nesting beaches, or walking up and down spraying mist on the hot sand.
All this will achieve is to highlight the location of eggs for the benefit of poachers.

Billy Ruff'n

“The resulting projections indicate that warmer, drier years will become increasingly frequent in Central America throughout this century. “
Didn’t I read somewhere that current climate models are not reliable in predicting regional weather patterns over long time periods?
In fact, I did, over at RC:
http://www.realclimate.org/index.php/archives/2007/05/climate-models-local-climate/
“Yet, whereas the global climate models (GCMs) tend to describe the global climate statistics reasonably well, they do not provide a representative description of the local climate. Regional climate models (RCMs) do a better job at representing climate on a smaller scale, but their spatial resolution is still fairly coarse compared to how the local climate may vary spatially in regions with complex terrain. This fact is not a general flaw of climate models, but just the climate models’ limitation……
…..Most GCMs are able to provide a reasonable representation of regional climatic features such as ENSO, the NAO, the Hadley cell, the Trade winds and jets in the atmosphere. They also provide a realistic description of so-called teleconnection patterns, such as wave propagation in the atmosphere and the ocean. These phenomena, however, tend to have fairly large spatial scales, but when you get down to the very local scale, the GCMs are no longer appropriate.”
Scary stories based on flimsy models once again.

MrV

Oh FFS. Maybe that’s why turtles head for the beach at night or early morning or late evening.

Lester Via

Yet additional proof that the dominant affect of the nearly undetectable climate changes is the loss of reasoning power in the minds of some humans.

Pamela Gray

Logically then, they must admit they believe anthropogenic CO2 increase (just the anthropogenic portion) has the power to cause an increase in ENSO heat producing events and/or decrease ENSO cooling producing events impacting that beach. So exactly how does this teeny, tiny percentage of total CO2 do that?
How long must we have to put up with this Nintendo science crowd?

I think we should have a very Sloooooowww response to this one. Appropriate measures to save the TURTLES…
Max

Perhaps the biggest danger of global warming is that it focuses attention AWAY from solving the real cause of problems. Global warming provides an excuse not to deal with real problems, except in a superficial fashion.
Sea turtles face extinction because of hunting and shipping. Turtles are air breathing. Like many other sea creatures they must spent time on the surface. Over the past 100 years the surface of the ocean has become quite dangerous, due to the invention of motorized shipping.
Nothing quite spoils a turtles day like being hit by a freighter. Unfortunately, there is currently no solution for the impact problem. And so long as money is wasted on global warming as the cause of turtle population declines, there will be no money spent on impact avoidance.
It could be that a simple redesign of ships bows could significantly reduce sea life mortality during impacts. We don’t know because so little research has been done in this area, while a fortune has been wasted tilting at climate windmills.
Are we so rich that we can afford to waste our hard earned tax dollars in this fashion, while ignoring so many areas that could provide real improvement?

cRR Kampen

“It makes you wonder how the turtles ever survived the Roman Warm Period or the Medieval Warm Period” – Does indeed. I also wonder how Ötzi the Iceman survived those.

Rodzki of Oz

Even assuming the assumptions of continued heating of sand, and the deleterious impact on turtles is true, the turtles that do survive are going to be the ones that are able to handle the temperature range. Those attributes will tend to be inherited by their young. Those turtles will then tend to pass on the same characteristics to their young, in turn. That’s how nature works. Otherwise how did any species survive any environmental perturbation?
What’s next?

DJ says:
July 2, 2012 at 5:33 am
On the presumption that sea turtles are reptiles and their eggs need to incubate at about 80˚F
==========
Surely, if global warming is a problem, why do turtles only lay their eggs in the tropics?
Why do turtles for instance not lay their eggs along the coast of Canada? We have one of the longest coastlines in the world, yet it would appear we do not have a single turtle laying their eggs along our coast.
Surely, if global warming is a problem, the turtles could simply start laying their eggs on a cooler beach. They do after all spend their entire lives traveling the oceans. What is it that restricts them to only laying their eggs in the tropics?
It would seem that the turtles, by choosing to lay their eggs in the tropics, are telling us that the rest of the world is too cold for their eggs to survive, and if we were to warm the rest of the globe to match the tropics it would increase the area available for turtles to lay their eggs. We might even see the turtles one day return to Canada.
http://www.turtlejournal.com/?p=3722
Winds continue to blow, temperatures continue to plunge, and tropical sea turtles continue to be expelled from the frigid waters of Cape Cod Bay. With numbers approaching 150 critically endangered turtles, beach patrols go out at each high tide in search for helpless animals that would quickly succumb to hypothermia without aggressive intervention.

The environazis move quickly to create a crisis, yet they all enjoy the merits of using toilet paper.
Not one will ever set the example to reduce their wants and needs to the songs they sing.

wobble

Of course their study was going to reach this conclusion. There’s no way they were going to spend their time and effort on this project only to say, “We have concluded that global warming will have no impact on turtle populations.”

Contrari

cartoonasaur wrote:
“Soooooo….. People were EATING the turtle eggs. Year after year. The turtles were very few in number because of this. Recently, people were prevented from eating the eggs. And so the turtles have recovered a bit. BUT! Global Warming! Hot sand! Oh noes! Send money! Spread the money on the sand! Hurray! See? The sand is cool! Now the turtles are saved again!”
Great idea, say I. Use the albedo power of the greenback to save the leatherback!

Mike Fowle

I see a Hollywood film here: the grizzled old scientist, with his laconic words of wisdom, the young, intense and beautiful researcher, shots of leatherbacks, and the host of villains, poachers, oil companies – somehow of course – and yes, climate sceptics. “Don’t you care about such beautiful creatures?”, she breathes.

Kev-in-Uk

another ridiculous piece of ‘research’ – another overhyped, piece of modeled if/why/maybe/could/might CAGW propaganda!
as per others…words (at least clean ones) fail me……

Bart Denson

I got a hunch the turtles have more to worry about than climate change.
http://www.snopes.com/photos/animals/seaturtles.asp

Geoff Alder says:
July 2, 2012 at 4:03 am
The temperature of beach sand is most largely dependent on the intensity of solar radiation of the moment. Surely this should be fundamental for the folk of Drexel University.

Normally. the closest a Drexel student ever gets to sand is sleeping off a weekend bender on the beach at Wildwood.

climatetruthinitiative

In addition to the frigate birds and crabs that George E. Smith mentioned, I read of one case where sharks were patrolling along the beach and gobbling up each baby turtle as it reached the water.
IanM