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Leatherback Sea Turtle Dermochelys coriacea. “A hypocrite is the kind of politician who would cut down a redwood tree, then mount the stump and make a speech for conservation.” Adlai E. Stevens . Jordan Taylor 2-10-14. Bio:. Life History Physical Characteristics Reproduction Diet
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Leatherback Sea Turtle Dermochelys coriacea “A hypocrite is the kind of politician who would cut down a redwood tree, then mount the stump and make a speech for conservation.” Adlai E. Stevens Jordan Taylor 2-10-14
Bio: • Life History • Physical Characteristics • Reproduction • Diet • Habitat • Territory & Range • Behavior • Predators • Parasites • Diseases • Endangered, Why? • Status • Conservation Management • Chain Reaction
Life History: • Hatchlings: • Adult female nests • She returns to the sea • Developing hatchlings do not have sex chromosomes • Gender is determined temperature • Mix of Males/Females- • “Pivotal” temperature- • 83-85 degrees Fahrenheit • Females- • Hotter temp • Males- • Colder temp • After 45 to 70 days- • Break out of eggs • Caruncle: Temporary tooth located on their snout • Remain in the nest • Absorb yolk, attached by umbilical to their abdomen • Provides energy for first few days, to the nest to offshore waters • Remain until the temperature of the sand cools • Less likely to be eaten by predators or overheat at night • Clues to find the water including: • Slope of the beach • White crests of the waves • Light of the ocean horizon
Life History: Cont. • Juveniles: • Size of dinner plates • Return to coastal until they reach sexual maturity (adulthood) • Feed over enormous areas- • Shallow waters • Sexual maturity- • 15 years • Leave coastal areas/migrate • Thousands of miles • To breeding areas to mate
Life Cycle: Cont. • Adults: • Females- • Nesting- • Come ashore to lay eggs • Wait for darkness before leaving water • Digs nest with rear flippers • 100 or more ping-pong ball sized eggs • May take a few hours or more • Cover and disguise nest before returning to water • Never sees hatchlings once born • Six weeks to two months later • Nesting season ends- • Return to hunting grounds • Not nesting again 2 to 3 years • Continue to mature • 30 year in captivity • 50-70 year old in wild • May live a century
Physical Characteristics: • Largest sea turtles • 4 to 8 feet in length • 500 to 2000 pounds • Shell- • small bones covered by rubbery skin with seven longitudinal ridges or keels • Skin- • Black with pale spotting • Pink spot on the dorsal surface of the head in adults • Paddle-like clawless limbs: black with white margins/pale spotting. • Jaw- • Tooth-like point located on each side of the gray upper jaw • lower jaw is hooked
Reproduction: • Nesting- • March to July • 5 to 7 times • 11 nests • 9 to 10 days of • Constructs at night in clutches with an average of 80 to 85 eggs • Eggs 2 inches in diameter • Incubation takes 55 to 75 days • Hatchlings: • Hatch at night • Return to their nesting beaches every 2 to 3-years • Sexual maturity about 16 years • Coloration- • Black with white flipper margins and keels • Significant Nesting Areas- • Caribbean- • Puerto Rico • U.S. Virgin Islands • Southeast Florida • Largest Nesting Areas- • Northern South America • West Africa
Diet: Crustaceans Sea urchins Tunicates Jellyfish Sea urchins Squid Crustaceans Tunicates Fish Blue-green algae Floating seaweed
Habitat: • Beaches: • Deep water • Rough seas • Vegetation • Sloped- Safe distance from dry sand and water
Territory & Range: • Distributed worldwide in tropical and temperate waters of the Atlantic, Pacific, and Indian Oceans • Small numbers far north: • British Columbia • Newfoundland • the British Isles • Small numbers far south: • Australia • Cape of Good Hope • Argentina • Recent estimates for the North Atlantic: • Range of 34,000 to 94,000 adult
Behavior: • Independent • Migrate: • Great distances between nesting and feeding grounds • Located: • High concentrations of jellyfish • Feed near the surface • Highest concentrations of prey
Predators: Piping Plover Red Knot Cephalopods • Predators: • Humans- #1 predator • Eggs: • Lizards • Birds- • Knots • Plovers • Raptors • Mammals- • Raccoons • Dogs • Hatchlings: • Cephalopods • Sharks • Large fish • Adult leatherbacks: • Jaguars • Killer whales • Large sharks
Parasites: • Conchoderma virgatum: • Species of barnacle • Not Harmful
Diseases: • Fibropapilloma- • Water pollution • Tumors Found on Body: • Lungs • Kidneys • Liver • Causes: • Oil spills • Runoff- • Chemicals • Fertilizers • Toxic waste • Destroys food sources: • Aquatic plants • Animals
Endangered, Why?: • Once the world’s largest population • Exploitation by humans: • Eggs • meat • Commercial fisheries/Over harvesting • Long-line fishing- Long fishing line with multiply hooks • Other factors: • Loss of nesting habitat from coastal development • Confusing hatchlings by beachfront lighting • Native predators/non-native predators • Marine pollution/debris • Watercraft strikes
Difference in Hooks Circle Hooks Long-Line Hooks
Status: • Delaware: • Seen in the Chesapeake Bay • Less frequently the Delaware Bay • Habitat loss/ change • Continues loss of open space to development • Federal: • Registered June 2nd,1970 • Endangered through out range • Listed endangered both state & federal governments
Conservation Management: • Increase hatchling populations: • Southeastern U.S. and U.S. Caribbean- • Nest protection efforts/beach habitat protection • Reduce leatherback deaths from long-line fishery • Coastal counties/communities have developed lighting regulations • U.S. nesting beaches continue for long-term protection • Pacific coasts of- • Mexico • Costa Rica • Other Central American countries • Eliminating Long-Line Fishing: • WWF- • Working with fisheries to switch to more turtle-friendly fishing hooks ("circle" hooks) • Satellite devices: • Tracks turtle movements
Chain Reaction: • Leatherback sea turtles are predators: • Affect prey population densities is unknown • Might have been important before their populations were reduced by harvesting • Leatherback eggs and hatchlings: • Food source for egg predator populations
All In All… • Populations decreasing • Support conservation groups • Stop pollution • Encourage local fisherman to be apart of conservation • Effect our eco-systems • Encourage others • Spread the word • Be involved in local conservation projects
Resources: http://www.fws.gov/northflorida/seaturtles/turtle%20factsheets/leatherback-sea-turtle.htm http://worldwildlife.org/species/leatherback-turtle http://www.nmfs.noaa.gov/pr/species/turtles/leatherback.htm http://conserveturtles.org/seaturtleinformation.php?page=leatherback http://www.seeturtles.org/915/leatherback-turtle.html http://www.turtles.org/leatherd.htm http://animaldiversity.ummz.umich.edu/accounts/Dermochelys_coriacea/#behavior http://people.wcsu.edu/pinout/herpetology/dcoriacea/conservation.html http://www.delawareonline.com/article/20060512/LIFE/605120326/Delaware-home-15-species-turtles