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Auteur Topic: Chelonia mydas (Green seaturtle)  (gelezen 16876 keer)
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« Gepost op: 2 Augustus 2008, 19:19:07 »

Bedankt Chandler Cobb voor het beschikbaar stellen van je foto's en de hulp bij de algemene gegevens over de Chelonia mydas en bescherming van deze prachtige zeeschildpad in het bijzonder.

Schildpaddennet crew

Kurt, Fred, Agnes, Jarno, Hans


De Chelonia mydas (Green Seaturtle) is de grootste onder de zeeschildpadden met een hard pantser.


Chelonia mydas bereikt een lengte tussen de 60 en 1.80 cm.


Gemiddeld zijn de mannen van Chelonia mydas iets groter.


De zwaarste Chelonia mydas ooit gevonden woog 600 pond.


Een meer gemiddeld gewicht van Chelonia mydas is 300 pond waarbij de mannen net even zwaarder zijn.


Hatchlings zijn bij hun geboorte 5 tot 10 cm groot.


De Chelonia mydas leeft in warme tropische oceanen op verschilende plekken op de wereld.


Alleen voor de eileg komen de vrouwlijke Chelonia mydas aan land, de rest van hun leven en manelijke dieren hun hele leven brengen ze door in zee, waarbij ze een voorkeur hebben voor ondiep water en dus dicht bij de kust leven.


Vrouwelijke Chelonia mydas leggen hun eieren in de nacht en doen daarongeveer 2 uur over, met een gemiddelde nest grote van 110-115 eieren.


Elke 2-4 jaar legt een voortplantings rijpe vrouwlijke Chelonia mydas een nest.


Over het voedsel van Chelonia mydas is nog niet zoveel bekend omdat het wenig geobserveerd is door mensen, zeegrassen en algen maken een belangrijk deel uit van hun natuurlijke dieet.
Soms worden ze herbivoor genoemd, maar hatchlings eten echter tijdens het opgroeien ook allerlei diertjes zoals zeeslakken zeewormen en sponzen.


Het kustgebied waar de Chelonia mydas hun eieren leggen is gevoelig voor verstoring en moet daarom zorgvuldig in stand gehouden worden.


Kunstmatig licht en met name in grote hoeveelheid langs de kust verstoord vrouwlijke Chelonia mydas bij de eileg, het kan zelfs gebeuren dat ze niet tot afzetten overgaan.


Hatchlings orienteren zich bij het verlaten van het nest op het maanlicht om de zee te bereiken, kunstmatige verlichting heeft de zelfde werking , hierdoor gaan ze de verkeerde kant op.
Het gevolg is dat ze het water niet bereiken, ten prooi vallen aan roofdieren of verdrogen in de opkomende zon.


Omdat het geslacht bepaald wordt door de broed temperatuur heeft het kunstmatig aanplanten van b.v palmen waardoor de nesten in de schaduw komen te liggen nadelige gevolgen op het natuurlijke proces.
Eieren in zand onder de 29C worden mannen, boven de 29 worden er meestal vrouwen geboren.


Ook bij deze schildpadden is de mens direkt verantwoordelijk voor de schade aan en de terug gang van de populatie.
Denk hierbij aan het gebruik van het strand, het bouwen van pieren/boothuizen in hun leefgebieden het gebruik van de pleziervaart vlak voor de kust.


Vooral in hun leefgebied in de Caribbean is het eten van de eieren en schildpaddenvlees van de Chelonia mydas een groot probleem, met name omdat hier een groot deel van de nu nog bestaande populatie leeft.


Olievlekken  is een andere bedreiging dit veroorzaakt schade aan de luchtwegen van de Cheonia mydas waardoor ze ademhalings problemen krijgen.
Verder huidproblemen en bloedwaarde veranderingen.



Onderzocht is dat Chelonia mydas in staat is om uitstekend te ruiken, zicht is minder ontwikkeld vooral op het droge.


Het nest seizoen is in Mei/Juni.


Voorspel van de manlijke Chelonia mydas begint met dat hij met zijn neus haar kop aanraakt, en zachtjes in haar nek en flippers bijt.


Als het vrouwlijke dier het manlijke dier niet wegduwt, dan is zij paringsbereid, hij klimt dan op haar rug en buigt zijn lange staart onder haar schild en de paring vindt plaats.


Uit onderzoek is gebleken dat een vrouwtje met meerdere mannen paart, hierdoor is er verschillend sperma aanwezig om haar eieren te bevruchten.


Vanaf de eileg tot de uitkomst van de eieren is een tijd nodig van 50 tot 70 dagen.





































Om de Chelodina mydas te beschermen en verdere afname van populatie aantallen te voorkomen moeten verschillende landen samenwerken.
Voedsel en nestplaatsen moeten beschermd worden.
Wetten die overigens meestal al bestaan moeten nageleefd worden.
Voorlichting over de beschermings maatregelen en waarvoor die nodig zijn dienen verspreid te worden.
Internationaal moeten er overeenkomsten gesloten worden over vervuiling van de zee en het kustgebied.
Maar boven al moeten deze overeenkomsten ook uitgevoerd worden door de betrokken landen.

Bedankt Chandler Cobb
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« Antwoord #1 Gepost op: 2 Augustus 2008, 19:20:34 »

HONOLULU ADVERTISER (Hawaii) 21 July 08 Memorial service held for slaughtered turtle
Malama Na Honu held a memorial service yesterday at the site of the killing of the green sea turtle at Laniakea Beach .
Volunteers of the guardian group that was set up to educate the public and protect the threatened species will place lei at the site where the turtle was partially buried in the sand, said Patrick Doyle, Malama Na Honu project coordinator.
Its belly shell had been cut off, and a flipper was missing. The top part of the shell, which was attached to the head, was found partially submerged in the sand. The head and three remaining limbs were still attached to the carcass, Doyle said yesterday.
The 200-pound female turtle, found on the beach Saturday morning by a beachgoer, was called "Honey Girl" because of her honey-colored shell, Doyle said. Her body has been taken to the National Oceanic & Atmospheric Administration facilities, where scientists will perform a necropsy.
The turtle was one in a group of about 20 that regularly comes to bask in the sun on the beach commonly called "Turtle Beach." The green sea turtle is included on the federal Endangered Species list.
http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=/20080721/NEWS25/807210353

KHNL (Honolulu, Hawaii) 21 July 08 Community still upset over Turtle's death (Duane Shimogawa)
Haleiwa: The North Shore community is still shell-shocked after the brutal killing of a harmless turtle.
Authorities still don't know who did it. The Hawaiian Green Sea Turtle, affectionately known as "Honey Girl" was found dead at Laniakea beach on Saturday.
It's the day after, but for many, the pain still lingers.
"I'm heartbroken," Visitor Pat Nehring said. "It brings tears to my eyes to think that someone would be needlessly cruel to an animal that would never, ever hurt them and that we've lost a turtle, our world has lost a turtle is heartbreaking."
Michael Lyons is the North Shore Neighborhood Board president. He said whoever killed the turtle should be prosecuted to the fullest extent.
"Well the act is done," he said. "We cannot change that part, but we hope people become educated. They understand what they're doing is wrong. They know that if they need food, we have food banks, we have opportunities to get free food."
Visitors and locals stopped by this makeshift memorial Sunday to pay tribute to a popular turtle.
"The one thing we've always appreciated coming here is how protective the community is of the turtles and how important they are to their lives and their image and what hawaii is about," Nehring said.
With Sunday's killing, it's giving officials even more incentive to help find a way to protect the threatened species.
"The laws are in place," State Senator Clayton Hee said. "We can look at enhancing penalties beyond the one year, $50,000 fine, but at the end of the day, we still need enforcement.And it's very difficult to have someone everywhere all the time."
Turtle protection volunteers try their best to keep the turtles safe, but there's only so much they can do.
"There's not a lot of things we can do differently," Malama Na Honu volunteer Patrick Doyle said. "Most of our focus in the last 24 hours has really been to support our volunteer group as they're grieving about the loss."
A loss that stings the small North Shore community and its many visitors.
"If anything, it makes me want to come and be more a part of the protection of these wonderful animals," Nehring said.
Killing a green sea turtle is a felony. If caught, a person could face up to five years in prison and a fine of up to $10,000.
The Department of Land and Natural Resources urges people to call them at 643-DLNR if you have any information about this incident.
http://www.khnl.com/Global/story.asp?S=8705561
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« Antwoord #2 Gepost op: 2 Augustus 2008, 19:21:32 »


 
HONOLULU ADVERTISER (Hawaii) 22 July 08 Turtle killed by boat propeller found - Meanwhile, search for person who butchered 'Honey Girl' continues (Eloise Aguiar)
Two more protected green sea turtles on O'ahu's North Shore became objects of investigation as the state continued to search for whoever it was who killed a third turtle, apparently for its meat, at Laniakea Beach.
A large dead turtle that was in an advanced stage of decomposition and a young live turtle suffering from tumors were recovered from North Shore beaches yesterday and Sunday, respectively.
Initial reports suggested that the large turtle was a victim of a shark attack but experts determined that it had been struck by a boat propeller.
"Propellers create very distinctive slashes on the turtle," said George Balazs, head of the Turtle Research Program for National Oceanic and Atmospheric Administration. "When it's a propeller injury there's no mistaking it with anything else.
"There's no evidence whatever of a shark attack," Balazs said. "The turtle has been hit by a boat. Of course we never know at this stage of decomposition if the turtle was hit by the boat first and died or if it died from some other unknown cause and then was hit by the boat."
Balazs said there was no evidence of butchering or human tampering on the carcass of the decomposed turtle carcass.
On Saturday, beachgoers discovered the partially buried carcass of "Honey Girl," apparently slaughtered for meat.
The state Department of Land and Natural Resources is looking for anyone with information about the killing of the 200-pound, 30-year-old turtle, said DLNR spokeswoman Deborah Ward.
Green sea turtles are protected by the federal Endangered Species Act as well as Hawai'i state law. As with monk seals, people must keep their distance from the animals or face charges, Ward said.
It is illegal to kill the animal for any reason, she said. "People are not supposed to be swimming near them and following them, which could be viewed as harassment.
"You can enjoy them but don't be sitting on them or grabbing them while they're swimming," she said.
Honey Girl's belly shell and one flipper had been cut off, according to Patrick Doyle, project coordinator for Malama Na Honu, a volunteer group that provides educational information and protection for the turtles at Laniakea Beach.
Doyle said he found organs in the water and Honey Girl was buried in the sand up to her top shell.
Many people had offered condolences but no one seemed to have any information about her death, he said, adding that people are talking about a permanent memorial at the beach.
A makeshift memorial with her photograph was set up at the beach, Doyle said.
"About an hour ago our largest turtle, Kuhina, hauled up out of the water and climbed right up onto her memorial site in front of her picture and has been resting here for an hour now," he said yesterday afternoon.
Honey Girl's remains were taken to NOAA for a necropsy and results are expected by tomorrow, said Balazs.
A third sea turtle was found Sunday suffering from tumors that had left the young animal weak and emaciated, Balazs said.
The 37-pound turtle is under a veterinarian's care and is suffering from tumors in the throat, he said, adding that a decision about whether to euthanize the animal hasn't been made.
http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=/20080722/NEWS01/807220333
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« Antwoord #3 Gepost op: 2 Augustus 2008, 19:22:31 »

TRINIDAD & TOBAGO EXPRESS (Port of Spain, Trinidad) 24 April 08 Turtles at cancer risk (Sateesh Maharaj)
Pollution is a heavy price paid by evolving nations. It is a fatal tax that takes a toll not only on the people of the country in question, but on its flora and fauna as well.
Prof John Cooper, Professor of Veterinary Pathology at the School of Veterinary Medicine, Mt Hope, recently made a startling discovery during an examination of a green sea turtle that was brought into the facility. The findings will hopefully shock the powers that be into immediate action.
He recalled: "The specimen was found in Chaguaramas. It was seen in the water near to one of the boating areas. It looked sick and lived for about ten minutes then died. The people who saw it noted swellings and contacted the wildlife section. It was collected and brought in to us. We looked at it, did tests and have no doubt that it is fibropapillomatosis."
Fibropapillomatosis, or FP, is essentially a skin cancer. Prof Cooper explained that, like skin cancer in humans and animals, this particular one shows itself in the form of big growths. They are on the head, around the eye, on the flippers, sometimes on the shell. They look unsightly but, like any cancer, sap energy. Those around the eyes and nose prevent the turtle from seeing and breathing properly. Those on the flippers hamper the turtle in swimming and makes it more likely to be damaged by boats, or caught in nets.
Prof Cooper said that there have been records of people finding turtles with strange diseases but there is no proof that any were FP because no samples were taken.
So why all the fuss about a 'turtle cancer?'
"I think the all important thing for members of the public, particularly Trinidadians who think a lot about environmental issues, is that we have strong evidence that turtles develop this disease because their immune system is affected because of pollution; not any particular kind. If you look at the distribution of where the disease has been reported, where there is a river coming out, there are factories, effluent... that's where turtles get it. We are arguing that these turtles could be telling us something about the sea and what we are doing to it before it starts to affect other species including, perhaps, human beings."
He said that the disease is widespread and has been found in all species of turtle except the leatherback. "That is interesting because that is the one that most people know and this country is most famous for. Then again, that may mean that no one has seen it. The main species affected by fibropapillomatosis is the green sea turtle. There have been reports from all over the world of the same disease at different times."
Prof Cooper said there is no evidence yet that the disease can be transmitted to humans.
"I put in the word 'yet' because with immuno-suppression in humans we don't know. At the moment there is no evidence that it is dangerous if people eat the meat. People should not be eating turtles in any case because they are protected by law."
He said the cancer was actually due to a virus which can be transmitted from one turtle to another. A turtle as badly affected as the one found off Chaguaramas would have been producing a lot of viruses.
Whilst little could be done to help turtles out in the wild, he said that one could cut down on its spread where turtles are kept in captivity. Every new marine turtle that comes into the country, he added, should be checked for the disease.
"In the wild there is no prevention, but we can remove the tumours by surgery. These animals suffer. The poor things can't see, they can't swim properly and many starve to death. I think we can safely say that there is a welfare reason for finding them at an early stage. They may not survive but we can help them either by surgery or euthanised so they don't suffer out in the ocean."
Prof Cooper said the school was trying to involve its students, particularly from the Caribbean, in wildlife projects. He said the School of Veterinary Medicine should also be recognised as environmental sentinels on the lookout for disease in local wildlife. He urged the public to report any cases of sick animals they find.
"We really are keen that our students are playing a leading part. We would like people to know that we have found this strange disease. We think that it is the first time that it is being reported in Trinidad although we know that over the years fishermen and tourists have said they have seen turtles with strange growths on them but we have no proper records. If anyone sees anything like this or anything related to wildlife we would like to know. We want to keep this small island beautiful. Anything that is telling us that we might be polluting the seas is important."
The School of Veterinary Medicine can be contacted at 645-2640, extensions 4213 and 4382.
http://www.trinidadexpress.com/index.pl/article_features?id=161314078
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« Antwoord #4 Gepost op: 2 Augustus 2008, 19:36:49 »

SOUTH PADRE ISLAND, Texas — When tourists found a 5-inch green sea turtle bloody and missing three of her flippers, the people who run a hospital for the endangered animals here gave her little chance of survival.
But the turtle persevered, thanks to injections of antibiotics and a forced diet of squid.
Somehow, she swam with just one flipper, even though she can only move in counterclockwise circles and has to push her now 10-pound body off the bottom with her head to breathe.
"The wounds have healed very nicely. The problem is she doesn't swim very well," said Jeff George, curator at the nonprofit Sea Turtle Inc., a 31-year-old turtle conservation facility that treats and returns injured sea turtles to the wild.
Now, her caregivers hope to make her what's believed to be the first sea turtle fitted with a prosthetic flipper.
Three-flipper turtles can return to the sea and two-flipper turtles can survive in captivity. But those left with only one after predator attacks or run-ins with boat propellers are usually killed.
Allison, named for the daughter of one of the tourists who found her, was spared because an intern begged for a chance to nurse her back to health the summer she was found.
Since then, Allison has adapted and grown to normal size for her age.
"With Allison, from the day she arrived, she was a fighter," said Lucia Guillen, the nonprofit's resident biologist and educator.
But because an Atlantic green sea turtle like Allison can grow to 450 pounds and live a century or so, her long-term prognosis with only one flipper is not promising.
"She would be destined to shallow water for the rest of her life and that becomes a quality-of-life issue," George said.
That's when they got the idea for a kind of bionic turtle.
A group of veterinary and medical professionals — including an assistant professor at the world-renowned University of Texas M.D. Anderson Cancer Center and the UT Dental Branch in Houston — have volunteered to help fit a prosthetic flipper to her left rear side.
She has a small bony stump there that could help hold a fake flipper, while making it difficult for her to use her clamping jaw to rip it off. Allison may have been the victim of a shark attack.
University of Texas' Dr. Sudarat Kiat-amnuay plans to develop a prosthetic using the same kind of silicon she uses to create facial prosthetics for humans.
Her dental expertise helps because the kind of tiny hardware used in dental implants are probably the best size match for Allison's bones.
Kiat-amnuay plans to use the same technique she would to create a prosthetic nose or ears for a human patient.
She'll use sculpting wax and molds created from a dead turtle's flipper and then custom fit one for Allison.
The silicon, now only tested in saliva, will be tested in sea water to make sure it holds up, she said.
Kiat-amnuay said she even plans to hand color the fake to match Allison's natural flipper.
The first trial flipper could be ready within a few weeks, though Kiat-amnuay and Sea Turtle Inc.'s veterinary director are still figuring out how to attach it.
It may seem silly going to so much trouble for a turtle, but Allison would not be the first animal to get a prosthetic replacement.
At least two dolphins, one in Japan and one in Florida, have successfully been fitted for prosthetic body parts.
Kiat-amnuay said part of the appeal is being the first to do so.
"It will be interesting and it will be fun," she said. And "if you're able to work on her, you may be able to apply it and work on more turtles."
Guillen, who initially thought Allison should be put down, said the work on her now might help others, especially because sea turtles missing even a single flipper are far less likely to successfully reproduce.
"If we can do something for other turtles, then keeping her alive is worthwhile," said Guillen. "We're hoping we can accomplish something with Allison that will benefit other turtles."


http://www.foxnews.com/story/0,2933,333670,00.html
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« Antwoord #5 Gepost op: 2 Augustus 2008, 19:37:50 »

SUN-STAR DAVAO (Philippines) 05 October 07 Saving the turtles (Dorothy Bangayan)
It is a Chinese belief that good luck befalls the person who sets a turtle free. If so, then I hope that luck will rub off on those who gathered to witness the flurry of activities that ensued at the Pawikan Sanctuary of Punta Dumalag in Matina Aplaya on September 23.
Scheduled for release was a sea green turtle christened "Liloh." This seagreen was acclimatized first at the Pawikan Sanctuary before he is set free. The reptile is tagged so that sightings can be reported in the future.
Davao City Councilor Leonardo Avila, who officiated the send offs, explained that domesticated turtles forget how to survive in the wild. Instead, they keep returning to the sanctuary and gravitate towards humans thinking that they will be fed. It is the job of the Pawikan Task Force Davao to retrain the survival instincts before sending them back to the ocean.
As one is set free, one is taken in. Another happy event was the turning over of a Hawksbill turtle by former owner, Michael Tan through the help of Vice Mayor Sara Duterte.
Michael rescued the turtle six years ago from some fishermen who were planning to kill it for the shell. Purchasing it for 500 pesos, he kept it under his care, until the day his uncle started talking about turtle soup.
VM Sara convinced him to surrender the pet to the sanctuary. Among the five kinds of pawikans, it is the hawksbill that is critically endangered because of their tortoise shell that are made into combs and bracelets. Hopefully this one can be rehabilitated and be set free in due time.
Originally intended to be a coal plant by the Aboitiz, this stretch of beach is now turned over to the DENR and to the city of Davao after turtle sightings.
In what is the only pawikan sanctuary and nesting site in an urbanized city, 2,638 turtles have hatched within the two years that it has been established.
The place is kept guarded and made conducive for nesting. No lights and loud sounds. After they nest, the eggs are transferred to a hatchery. Aside from poachers and animals, the eggs must be protected from seawater or rain.
The survival rate, if left on their own is only 30 percent. Now, the survival rate has shot up to 90 percent Once out on the sea, only one or two turtles in a thousand survive, a rate of 1 percent.
Pawikans return to nest on their birthplace after thirty years. This means that Punta Dumalag has long been a nesting site. If this spot was left unprotected, it could mean the extinction of pawikans.
Trading, collecting, transporting, inflicting injury and killing are all illegal acts that are punishable by law with a minimum of three months to six years in prison depending on the species. A ban on fishing is also imposed in the area.
Because of this, it has become a spawning area for fishes, as evidenced by the silvery schools of fishes glinting in the sunlight on our visit. Other wildlife have flourished. Several species of birds have been spotted like the egret and the seagull.
Dolphins and whales are sometimes seen in the early morning. The area itself has already become rich in natural resources -- a source of food. Already, WWF has contacted them because a one ton leatherback from Japan was sighted at the Davao gulf.
"We are doing this for our children" Councilor Leo said. Future plans include setting up a marine learning center for educational purposes.

http://www.sunstar.com.ph/static/dav/2007/10/05/life/saving.the.turtles.html
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« Antwoord #6 Gepost op: 2 Augustus 2008, 19:38:54 »

NAPLES DAILY NEWS (Florida) 20 April 06 Turtle expert hopes to test theory in Gulf (Jeremy Cox)
Brimming with green turtles, a boat breaks up in a raging storm between Cuba and Key West. The turtles escape into the sea.
Months later and 600 miles away, the turtle fishermen recapture two of the turtles in almost the exact spot where they had been first caught off the northern coast of Nicaragua. The fishermen had branded their initials onto the turtles’ backs, so there was no mistaking their identity.
That anecdote and others, collected by the late University of Florida researcher Archie Carr in his 1956 book, “The Windward Road,” suggested that sea turtles use an extra sense to navigate great distances.
But how? That mystery puzzled scientists for years until a University of North Carolina at Chapel Hill biologist proved that turtles have a kind of internal Global Positioning System.
Ken Lohmann will discuss his landmark research tonight at Naples Community Hospital’s Telford building as the last speaker in the “Sea Secrets” lecture series. The University of Miami’s Rosenstiel School and the Ocean Research and Education Foundation are sponsoring the talks.
Lohmann, though, has an ulterior motive in this trip.
He wants to test his theories, which he developed on Florida’s Atlantic Coast, on Gulf Coast sea turtles. He plans to meet with David Addison, a leading researcher at The Conservancy of Southwest Florida, to discuss that prospect.
In a study, University of North Carolina-Chapel Hill biologist Ken Lohmann placed harnesses on sea turtle hatchlings and put them into a large tub to keep track of the direction they swam. His landmark research showed sea turtles use the Earth’s magnetic field to navigate great distances.
“It would be interesting to see if the hatchlings from the west coast have the same responses or if there’s some difference,” Lohmann said.
The Conservancy has been monitoring sea turtle nesting on Keewaydin Island for 25 years. Scientists know that once turtles emerge from their nests on the beach, they swim in a straight line due west into the Gulf of Mexico.
“Where they go from there, we might get some ideas from the work Ken does,” Addison said.
In general, sea turtle hatchlings on Florida’s east coast follow the Gulf Stream to the Atlantic gyre, a giant, circular current of water that encompasses the Sargasso Sea. There, sea turtles find few predators along with a ready supply of food in the form of floating sargassum weed.
On the Gulf Coast, where sea turtles nest in fewer numbers, hatchlings must eventually turn south and then east through the Florida Straits to reach the Gulf Stream.
How do hatchlings, with no navigating experience whatsoever, stay inside the protective gyre? And how are older sea turtles able to home in on favorite feeding areas from great distances away?
Certain migratory birds and fish, particularly salmon, are known to use the earth’s magnetic field to reckon direction.
For years, scientists suspected that sea turtles also possessed a “magnetic sense,” but there were competing theories. One proposed that sea turtles follow trails of chemicals in the ocean.
“Virtually nothing was known at the time about how sea turtles guide themselves through the ocean,” Lohmann said.
Here is a brief explanation of how magnetic sensing works:
Each part of the globe has a unique magnetic pull. For an animal to form what Lohmann calls a “magnetic map,” it would have to learn to distinguish between slightly different magnetic fields.
When diagrammed, the magnetic lines resemble ripples of water surrounding the Earth. They emerge from the Southern Hemisphere and wrap around to the top of the planet. Because of this gentle arc, the lines strike the planet at different angles, progressing from 0 degrees at the equator to 90 degrees at the North Pole.
Once a sea turtle has memorized the angle of inclination at its favorite patch of sargassum, it can easily find its way back.
On his Web site, Lohmann explains the phenomenon this way: “If the angle is too steep, the turtle knows that it is too far north and therefore needs to travel south to reach home. If the angle is too shallow, then the turtle knows it is too far south.”
To confirm this theory, Lohmann and a team of researchers captured several juvenile green turtles in a feeding area off Melbourne Beach. The researchers placed the turtles in a large blue bucket surrounded by a coil system that, with a surge of electrical current, could generate a weak magnetic field around the turtles.
Half of the turtles swam in a field that replicated what would exist off the southern coast of Georgia, 210 miles north of Melbourne. The other half were tricked to think they were the same distance away, except off the coast of Key Largo.
The turtles swam in place, apparently unaware they were in nylon harnesses and tethered to a rotatable lever. The “northern” turtles swam to the south while the “southern” turtles headed north.
Lohmann and the other researchers published the study in the April 2004 issue of the prestigious journal Nature.
Understanding the sensory world of sea turtles is important for their conservation, Lohmann said. Every sea turtle species that frequents Florida’s waters is listed as either endangered or threatened.
The night with Lohmann begins with a reception at 5:30 followed by the lecture at 6:15. The event is open to the public. Seating is limited.
Turtle research
Ken Lohmann will discuss his landmark research tonight at Naples Community Hospital’s Telford building as the last speaker in the “Sea Secrets” lecture series. The night with Lohmann begins with a reception at 5:30 followed by the lecture at 6:15. The event is open to the public. Seating is limited.
http://www.naplesnews.com/news/2006/apr/20/turtle_expert_hopes_test_theory_gulf/?local_news
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« Antwoord #7 Gepost op: 2 Augustus 2008, 19:39:44 »

THE TRIBUNE (Fort Pierce, Florida) 27 August 05 Turtles stuck on beach by Fort Pierce after Katrina (Derek Simmonsen)
Hutchinson Island: While Hurricane Katrina mostly bypassed the Treasure Coast, its side effects took a swipe at one group of local residents: baby sea turtles.
Between 100 and 200 hatchlings were found scattered in seaweed and sargassum on the beach near the Fort Pierce South Jetty on Friday morning, and volunteers spent the day helping collect them so they could be returned to the ocean later.
The turtles might have hatched on Wednesday or Thursday night and been caught in seaweed and pushed back to shore by heavy waves and wind, said Bob Ernest, president of Ecological Associates in Jensen Beach.
"They all looked like they hatched. They just came the natural way out of their nests and happened to do that at a bad time," he said.
In addition to the hatchlings, scientists also reported damage to sea turtle nests up and down the Treasure Coast, although the damage was not nearly as bad as what occurred during last year's hurricanes.
Local residents first noticed the hatchlings, evenly divided between loggerhead and green sea turtles, near the jetty early Friday morning. Krista Muccino, 16, came to the beach to surf with her friends when she saw one of the turtles.
"I said, 'Oh my God! There's a sea turtle,'" she said. "Then we were walking up and down and there's a million of them. They were everywhere."
Other beachgoers reportedly saw the turtles in different spots and alerted police. About a dozen people spent the day combing through tangles of seaweed and sargassum on the beach, battling rain, strong winds and heavy waves as they looked for surviving turtles.
Lisa Paylor, a receptionist with the Humane Society of St. Lucie County, was one of several volunteers from the office who came to help.
"They're all tangled up and meshed up in there," she said. "They can't crawl out."
The white-bottomed green turtles and slightly smaller, dark loggerheads were placed in buckets with sand, seaweed and a little water and taken to Ecological Associates, where scientists planned to hold them until they could be released back into the water. Workers hoped to send them out Friday night or sometime tonight, depending on weather conditions, Ernest said.
If not, they will be kept in a rehabilitation center and taken offshore to be returned to the wild. The green turtles are endangered and the loggerheads are threatened, Ernest said.
Ernest said the turtles likely came out of about two or three nests on Hutchinson Island.
"If these folks hadn't started collecting them, they would have perished in the sun," he said.
The jetty was the only area that saw hatchlings beach, mainly because the currents in the area helped push seaweed onto the shore there, said Erik Martin, scientific director for Ecological Associates.
In addition to the hatched turtles, the storm also hurt sea turtle nests at various locations on Hutchinson and Jupiter islands. Based on the nesting surveys they conduct, scientists estimated about 200 loggerhead nests, three green turtle nests and three leatherback turtle nests were destroyed, Martin said.
That was minimal compared to the amount of damage that last fall's hurricanes did to the nests, when about 75 percent of the green turtle nests were destroyed and 25 to 30 percent of loggerhead nests were damaged, Martin said. Katrina destroyed about 5 percent of the loggerhead nests and about 1 percent of the green turtle nests in the area.
"Percentage-wise, that's not bad for having gone through a storm that's passed pretty close by," Martin said. "It's certainly something the turtles could recover from."
Additionally, some sea turtle eggs might be ruined by saltwater brought in by higher tides and heavy wave action, Martin said. Normal amounts of saltwater seeping into the ground doesn't damage the nests, but the extra water from the storms can stop development of the eggs.
"There is a potential that the effects of the storm will go beyond what we've seen," he said.
It was not clear whether there was any difference between nest damage reported in renourished beach areas and natural beaches, Martin said. St. Lucie County Erosion District Manager Richard Bouchard said the beach fared well after the storm, although there was some drop-off in the Fort Pierce area around the jetty.
Elsewhere in the region, 29 adult loggerhead turtles were released Friday morning at Sebastian Inlet State Park in Melbourne Beach by the Florida Park Service and National Marine Fisheries Service. The 4-year-old turtles were part of the Turtle Excluder Device program, which tested commercial fishing equipment fitted with devices that allow turtles to pass through nets while still trapping small animals, like shrimp.
The Indian River Lagoon was an ideal location for the release, because it allows the turtles access to the Atlantic Ocean for migration, according to the park service.
http://www.tcpalm.com/tcp/local_news/article/0,2545,TCP_16736_4032314,00.html
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