Sea Turtle Biology and Conservation Sea Turtles in Mythology • Turtles have long been revered in myths. • Most Indian tribes see turtles as being sacred. • The are seen as being supernatural because of their powers for survival. • The Greeks saw turtles as standing for wisdom. More Sea Turtle Myths • In a Chinese myth, a turtle was believed to have developed the world within its shell. • Some Indians believe that the world in which we live was formed on the back of a turtle. Sea Turtles are still important in human culture today. Sea Turtle Identification 1. Kemp's Ridley 2. Hawksbill 3. Loggerhead 4. Green 5. Leatherback Green Turtle • Most common species of sea turtle. • It’s called the green turtle because of the green color of the fat under shell, they are not actually green. Green turtle • It is one of the largest species of sea turtles: 3ft long, up to 300 lbs. • Green turtles can be recognized because they have one pair of scales in front of their eyes, instead of 2, like most sea turtles Black turtle • Black turtle is named for the black/gray color of its shell. • It is primarily located in the Eastern Pacific, and is protected in the Galapagos and some areas of Mexico. Flatback Turtle • They are named Flatback because of their flattened shell. • Flatback Sea turtles are only found in Australia. Loggerhead Turtle • Loggerheads can grow up to 350 lbs, between 31-42 ins. • They can be identified by their large head, reddish brown carapace (top), and dull brown plastron (bottom). Hawksbill Turtle • The beautiful shell of Hawksbill turtles is often used for jewelry Olive Ridley • This is one of the smallest sea turtles, weighing only 100lbs. It is also one of the most numerous species of sea turtle. • It is named Olive Ridley because of the olive coloring. Kemp’s Ridley • Kemp’s Ridley is the most endangered species, as well as the smallest: only grows to 24-28 ins and 77100lbs. • They are olive green in color. • They only nest on one beach in the world, in Rancho Nuevo, Mexico. Leatherback • Can dive the deepest and travel the furthest of any other turtle. • They have tough leathery skin covering their back. Leatherbacks • Largest sea turtle, up to 7 ft long, 1200lbs. • Instead of a solid shell they have bones in their skin that form 5 ridges. Navigation Navigation • Navigation is finding the way from one location to another. • What are some ways that people can navigate? Navigation • 1. Compass • 2. Stars • 3. Position of Moon and Sun • 4. Maps • 5. Landmarks • What are some ways that sea turtles may navigate in the water and on land? Navigation • • • • Sight Position of the moon Wave direction Internal compass (turtles that we know use this: loggerhead and leatherback) Navigation • So how do you think baby turtles navigate from the nest to the ocean? Navigation • 1. Move away from silhouettes at the top of the beach • 2. Orient themselves toward the brightest light (moon on water in low populated beaches) • They can sense the direction of waves when in the water • Some use a magnetic compass. Navigation • What are some reasons a turtle might have to navigate in the ocean? • How far do you think turtles may migrate? Navigation • • • • They migrate to find: food mates and beaches to nest on Navigation • Some turtles migrate over 2600 km but most will only travel 1000 km. Reproduction Reproduction • Turtles lay eggs in nests on the beach, usually at night. • They can lay up to several hundred in one nest. • Many turtles can create several nests over a few weeks, during the reproductive season. Reproduction • After laying all their eggs, the female turtles return to the ocean. • After sixty days the baby turtles will emerge and travel to the ocean, and must defend themselves. Conservation • 1. What is making the sea turtles endangered? • 2. How can we protect turtles and their habitats? • 3. Problems being faced with enforcing laws. • 4. What can we do? 1. What is making the sea turtle endangered? • Coastal development • A. Destroying nesting beaches. • B. Increasing pollution in bays. • C. Distracting hatchlings with light. • D. Beach vehicle activity. 1. What is making the sea turtle endangered? • Net & Shrimp trawls • A. Entanglement and drowning. • B. Used in trade for shell and meat. • C. Destroying feeding grounds. 1. What is making the sea turtle endangered? • Industrial development • A. Sand walls preventing nesting • B. Oil spills • C. Damage to coral reefs and sea grass beds. 1. What is making the sea turtle endangered? • Natural Mortality • A. Predation as hatchlings • B. Predation as juveniles and adults • C. Old age 2. How can we protect the turtles and their habitat? • Protect nesting grounds • A. Reserves and wildlife refuge • B. Relocate eggs to hatcheries. • C. Patrol the beaches from poachers • D. Prevent coastal development and activity. 2. How can we protect the turtles and their habitat? • Education • A. Get locals involved • B. Decrease international trade of products • C. Scientific research • D. Tell others 2. How can we protect the turtles and their habitat? • Improvements • A. Improve fishing trawls (TED) • B. Protect with turtle farms • C. Decrease pollution and trash • D. Get involved 3. Problems being faced with enforcing laws • Not all countries have the money or manpower to control poaching on beaches. • Violations of poaching may only face a simple fine, or may be disregarded. 3. Problems being faced with enforcing laws • Jurisdiction varies between governmental agencies: • water = fishery depart. • land = wildlife and forest depart. 3. Problems being faced with enforcing laws • Turtle farms for trade and reinstatement cost millions of dollars and take 20 to start. • “to some people . . . trade and conservation appear to conflict, but if properly applied, they could well be the key to surviving the species” • --H. Reichart 3. Problems being faced with enforcing laws • Local people are not educated enough in rural countries and need turtle meat as a source of protein. • Not all nesting beaches can be protected. 4. What can we do as students? • We can do our part in conservation by simple acts: • 1. Picking up trash on the beach. • 2. Cutting soda 6-pack rings, and recycle • 3. Don’t buy marine animal products and souvenirs • 4. Be careful what food we eat. 4. What can we do as students? • We can go further by: • 1. Volunteer in helping scientists do research. • 2. Adopt a turtle. • 3. Become members of animal conservation societies. • 4. Write to your Congressman. Interesting Facts: Archelon is the oldest known fossil at 150MYA. Found in 1970’s in S.Dakota. Archelon: Measured 15ft long (from beak to tail) and 16.5ft wide (including flippers and shell), weighing @4,500lbs. Archelon: Primarily ate giant squid. Photo Credits • • • • • • • • www.cccturtle.org: #1,7,11,16,17,19,24,29,37,42 www.co.broward.fl.us/bri00600.htm: #5 www.yoto98.noaa.gov/books/seaturtles/seatur1.htm: #6 www.ex.ac.uk/telematics/EuroTurtle/homep.htm: #8,10,12,14,18,20 www.baja-tortugas.org/conservation.html: #13,26,32,36,38 www.bonairenet.com/turtle/turtle.htm: #10,15,21,49 www.seaworld.org/Sea_Turtle/seaturtle.html: #23,41,47 www.nps.gov/pais/turtles.htm: #25 Photo Credits cont. www.turtle.ky: #43, 46 Webhost.bridgeW.edu/EsandG/blkbeach.htm: #45 www.itec.edu.org/conservation.html: #8, 22, 48 J. Ripple. 1996. Sea Turtles. Voyageur Press: #33, 35, 39, 40, 44 Jeff Seminoff: #9 John R. Hendrickson: #4,27,28, 30, 34 Hometown.aol.com/gonyosoma/folklore.html: #2 www.bonairenet.com/turtle/turtle.htm: #9, 10 www.bhigr.com/pages/info/info-rept.htm: #50,51,52