Rescue and Research Facilities for Sea Turtles
Many sea turtles end up at rescue and rehab facilities because they are injured or sick. At these facilities the animals are treated and if possible released back into their native habitat. The turtles are treated for injuries to their flippers caused by predation, fishing line and trap rope entanglements, and often end up in amputation of the affected appendages.The shell can also be damaged by collisions with boats. Some animals are being treated for intestinal implications, like ingesting plastic bags, balloons, and fishing lines and hooks. In South Florida many turtles undergo surgery for removal of viral tumors (follow Fitzy's story at

Turtle Hospital in Marathon, Fl

http://www.turtlehospital.org/blog/). Besides rehabilitation and rescue these facilities offer field trips, education and some provide opportunities for adoption of animals, as well as for internships and volunteer work.

There are several rescue and rehabilitation facilities around the world, but here are a few of them.

Sea Turtle Inc is located in South Padre Island Texas and is primarily involved with the Kemp's Ridley turtles, but has other turtles as permanent residents like Allison, an Atlantic Green turtle that lost three of her flippers and now swims with prosthetic flippers. MJ   the loggerhead lost all four of his flippers in a shark attack and Hang10, a Kemp's Riddley with a genetic birth defect and now travels to local events and schools  to educate people.
http://www.seaturtleinc.org/

 The Turtle Hospital in Marathon, Florida, who has Fitzy amongst other turtles in need of rescuing. The photo to the right, courtesy of turtlehospital.org, shows the tumors all over Fitzy, who is now cancer free.
 http://www.turtlehospital.org/blog/


The South Carolina Aquarium offers help for the sea turtles as well.
For more information on adoption, nest conservation, current residents and pictures please go to the websites listed below.
http://scaquarium.org/STR/

Allison @ seaturtleinc.

 

 

 

Migration and Navigation of the Loggerhead turtle
 Loggerheads travel thousands of miles across the Atlantic Ocean to the  circular current systems called gyres that serve as open ocean nurseries, where they stay for several years to mature. The male turtles will then migrate to their foraging areas, while the females eventually will return near their birth place to lay their eggs.
Sea turtles are using the earths magnetic field , the sun, and skylight polarization to navigate across the oceans and find specific destinations, as well as to return to the beach where they were hatched. They calibrate their built in "compass" to the horizon when they are first born and utilize the oceans waves to guide them several miles out to sea after they first enter the water. Since these turtles are sensitive to small differences in field inclination and intensity (Lohman, 1996) they can use the fields that exist at specific locations to help them navigate.
They also use those fields as markers along their journey, and detect errors in the course by changes in the angle of the magnetic field.
Metal cages are often placed over the nests to protect the eggs from predators like dogs, foxes, and especially racoons. However, some studies seem to indicate that the metal in those cages disrupts the

photo courtesy by sciencedirect.com

calibration of the turtles to the magnetic field. One option to resolve that issue is to construct cages made of non magnetic material. The lights from hotels and streets near nesting beaches can also distort the hatchlings, as they try to find their way towards the ocean, and take them inland instead. Having dimmed or no lights during hatching season can help the little turtles with their journey.
 www.nature.com/nature

Sources
Geomagnetic map used in sea-turtle navigation, by K. Lohmann, Nature|Vol 428|29 April 2004|
www.nature.com/nature
Magnetic field distortion produced by protective cages around sea turtle nests, by Irwin, Horner,Lohmann Biological Conservation 118 (2004) 117-120

Sea Turtle Video

...And meet their Smaller Cousins

The Hawksbill Turtle (Eretmochelys imbricala)

courtesy of hawksbillseaturtle.org

This turtle is named after its narrow head  with its bill like beak. An adult grows between 2 to 3 feet long and weighs between 100 to 200 lbs. It has a brightly colored carapace with overlapping scutes, while all the other sea turtles have non overlapping scutes.

Olive Ridley  (Lepidochelys olivacea)
It is named after its pale green carapace. It grows between 2 to 2.5 feet long and weighs between 75 to 100 lbs. It has 6 or more scutes on it's shell, and is one of the most abundant of the turtles.

 (photo courtesy of aquariumofpacific.org)



Kemp's Ridley (Lepidochelys kempii)

 Richard Kemp discovered these turtles in 1880, and the animals were named after him. They are the smallest of the sea turtles growing only to 2 feet, and between 75 to 100 lbs. Their carapace is wider than it is long, and has an olive gray color. The head is triangular shaped with a hooked beak. This is the only species that primarily nests during the day. These turtles are currently listed as critically endangered.
http://www.seaturtleinc.org

Meet some of the Larger Turtles

The Leatherback Turtle (Demochelys coriacea)

photo courtesy of library.thinkquest.org

It is the largest of all the sea turtles, between 4 to 8 feet long, and weighs between 500 and 2000 lbs. It has a smooth, leathery, flexible carapace (shell), and is the only sea turtle with no scutes (scales). It is the only one of the species that has longitudinal ridges down the carapace. The shell is black with gray, white or pink spots. These animals have the furthest migration route of all the sea turtles, traveling about 10000 miles a year from Asia to the West Coast of the USA. The Leatherbacks are currently listed as critical endangered, and are at risk to be extinct in the next 20 years.

photo courtesy of virginiaherpetological society.com

Green Turtle (Chelonia mydas)

photo courtesy of conserveturtles.org

It is the largest of the hard shelled sea turtles, reaching a length up to 4 feet and weighing up to 500 lbs.Their carapace is olive brown to almost black and has 4 pairs of scutes (scales). It also travels thousands of miles in search for food. It is currently listed as endangered.

The Loggerhead Turtle (Caretta caretta)
it is named for its massive head and jaws, grows up to 4 feet long and weighs between 200 to 400 lbs. It is reddish brown with a slightly heart shaped carapace. More detail about this turtle can be found through out this blog site.





The Flatback Turtle(Natator depressus)

courtesy of marinebio.org

courtesy of seeturtles.org

Got it's name for it's flat carapace, which is colored pale, grayish green. It has 4 pair of scutes in it's shell, and the edges of the carapace are distinctly up turned. It grows up to 3 feet long and weighs up to 200 lbs. They are only found around Northern Australia and Southern Indonesia.

The photo on the left shows the carapace with the scales, typical for the Flatback sea turtles.

Most of this information was obtained from http:www.seeturtles.org/1893/sea-turtle-identification.htlm
seeturtles.org/

Loggerhead Turtle Reproduction
(most of the references are from the book Biology of Sea Turtles, Volume 1 and II, edited by Peter Lutz, CRC Press)

It is estimated that Loggerhead turtles will reach sexual maturation between 30-35 years old. Even though they live in the ocean, the females return to land close to where they were hatched to lay their eggs (interoperous reproduction). The males and females leave their separate feeding areas and migrate to a  place to mate, and afterwards the males will return to their feeding grounds, while the females migrate to their nesting beaches. There are three requirements for nesting to occur. The condition for adult turtle activity must be favorable, must be conducive to embryonic development and survival, and must favor hatchlings survival. If the conditions are met, a 80% hatching success can be achieved, unless stressors like environmental changes, predation and microbiological infections occur.

 

eggs in a nest

The female turtle lays her eggs  on a warm, sandy beach. At night she digs a hole in the sand  drops her eggs into it and covers them up. These nests, called clutches, contain between 19 to 112 eggs and the female turtle will create 3-4 clutches during a season, but only every 2 to 5 years. The baby turtles will hatch after 6 to 13 weeks of incubation. The temperature of the sand determines the gender in all turtles. Cooler temperature produce male turtles, while warmer temperatures are responsible for the females. The temperature of the sand is  crucial to the survival of  the eggs as well.
24 C to 26C are ideal, less than 23 C seldom hatch and greater than 33C never hatch, because the eggs get nearly cooked.

"here I am"

After 6 to 13 weeks the hatchlings emerge from the nest usually near evening, when the temperature is cooler and they are not as likely to be detected by predators as during the day. They scramble towards the ocean and their long and dangerous journey begins.

small, but ready to go

Sea Turtle Protection
Sea turtles are related to the land turtles but have special adaptations like flippers to help them move under water. However, they still have to come  on land to lay their eggs. There used to be at least 27 species of sea turtle of which 19 were extinct a very long time ago. Fossil analysis show that they date back to the Jurassic period. Since these turtles were highly specialized, they did not adapt well to environmental changes, which is believed to be one of the causes for their extinction. Seven of the eight remaining species are currently listed as threatened, endangered and critically endangered like the leatherback turtle (Dermochelys coriacea) and the Kemp's Ridley (Lepidochelys kempii) due to direct and indirect human impact, while one species is actually extinct.
The logger head turtles (Caretta caretta) were listed as vulnerable in 1992 and are currently listed as threatened. These turtles are directly impacted by human stressors like disturbing nesting sites by poachers and onlookers, ocean debris, and pollution,  but the biggest culprit is massive accidental catches during their long migrations.

(photo from greenpiece.com)
turtle entangled in debries

(photo from destination-scuba.com)
accidental by-catch of turtles

Better management of the animals and their habitat is needed to protect them from extinction. One way to help them is by limiting direct access to nesting grounds, creating national parks, as well as protecting their foraging and mating areas, since turtles return to the same sites year after year. Some protection measures  to save these animals are being implemented, but a lot more effort is needed to guarantee their survival.