1. Green Sea Turtles ( Endangered ) Done by: Agnes Toh 4.7 [1]

2. Introduction The Green sea turtle (Cheloniamydas) or green turtle is a large sea turtle of the family Cheloniidae. Its range extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans. Their common name derives from the usually green fat found beneath their carapace (upper shell).Possessing a dorsoventrally flattened body covered by a large, teardrop-shaped carapace and a pair of large, paddle-like flippers. It is usually lightly coloured, although parts of the carapace can be almost black in the eastern Pacific. Unlike other members of its family, such as the hawksbill sea turtle and loggerhead sea turtle. The adults commonly inhabit shallow lagoons, feeding mostly on various species of sea grasses.

3. Description Its appearance is that of a typical sea turtle. C. Midas has a dorsoventrally flattened body, a beaked head at the end of a short neck, and paddle-like arms well-adapted for swimming. Adult green turtles grow to 1.5 metres (5 ft) long. While individuals have been caught that reached weights of up to 315 kilograms (690 lb), the average weight of mature individuals is 110–190 kilograms (240–420 lb). The carapace of the turtle has various colour patterns that change over time. Hatchlings of C. mydas, like those of other marine turtles, have mostly black carapaces and light-colored plastrons. Carapaces of juveniles turn dark brown to olive, while those of mature adults are either entirely brown, spotted or marbled with variegated rays. Underneath, the turtle's plastron is hued yellow. C. mydas limbs are dark-colored and lined with yellow, and are usually marked with a large dark brown spot in the center of each appendage.

4. Habitat Green sea turtles move across three habitat types, depending on their life stage. They lay eggs on beaches. Mature turtles spend most of their time in shallow, coastal waters with lush sea grass beds. Adults frequent inshore bays, lagoons and shoals with lush sea grass meadows. Entire generations often migrate between one pair of feeding and nesting areas.Turtles spend most of their first five years in convergence zones within the open ocean. These young turtles are rarely seen as they swim in deep, pelagic waters.

5. Behavior As one of the first sea turtle species studied, much of what is known of sea turtle ecology comes from studies of green turtles. The ecology of C. mydaschanges drastically with each stage of its life history. Newly emerged hatchlings are carnivorous, pelagic organisms, part of the open ocean mininekton. In contrast, immature juveniles and adults are commonly found in sea grass meadows closer inshore as herbivorous grazers.

6. Diet Adults are usually referred to as herbivores although as hatchlings they are omnivores. Their diet consists primarily of algae, sea grasses, and seaweed. Greens have a finely serrated (sawlike) beak that allows them to scrape algae off rocks and tear grasses and seaweeds.

7. Threats Intentional threats include continued hunting and egg harvesting. More dangerous are unintentional threats, including boat strikes, fishermen's nets that lack turtle exclude devices, pollution and habitat destruction. Chemical pollution may create tumours; effluent from harbours near nesting sites may create disturbances; and light pollution may disorient hatchlings. Habitat loss usually occurs due to human development of nesting areas. Beach-front construction, land "reclamation" and increased tourism are examples of such development. An infectious tumour-causing disease, fibropapillomatosis, is also a problem in some populations.

8. Conservation Caught in a fisherman's net, they are unable to surface and thus suffocate. However, some relatively inexpensive changes to fishing techniques, such as slightly larger hooks and traps from which sea turtles can escape, can dramatically cut the mortality rate. Turtle Excluder Devices (TEDs) have reduced sea turtle bycatch in shrimp nets by 97 percent. Beach development is another area which threatens sea turtles. There has been a movement to protect these areas, in some cases by special police. In some areas, such as the east coast of Florida, conservationists dig up sea turtle eggs and relocate them to fenced nurseries to protect them from beach traffic. Since hatchlings find their way to the ocean by crawling towards the brightest horizon, lighting restrictions can prevent lights from shining on the beach and confusing hatchlings. Sea turtle-safe lighting uses red or amber LED light, invisible to sea turtles.

9. Interesting facts!!! Most Sea Turtles are nomads and travel about 1,300 miles a day! Leatherback Sea Turtles have the longest migration of all Sea Turtles. A Sea Turtle's shell is tough as a rock, so when diving into waters it would never crack. On a Sea Turtle's shell there are strange markings. A lost culture has believed they could tell when the end of the world could be by reading the marks.

10. References http://library.comthinkquest.org/3822/886008577380.htm http://en.wikipedia.org/wiki/Sea_turtle

11. References ( Pictures) http://www.google.com.sg/imgres?q=animated+green+sea+turtle&um=1&hl=en&sa=N&tbm=isch&tbnid=SJBgwxz93lrr9M:&imgrefurl=http://www.picturesof.net/pages/090122-140636-444048.html&docid=L_ejJvvrDvV4zM&w=300&h=184&ei=UjIuTsHtDofUmAXw35xB&zoom=1&iact=rc&dur=708&page=2&tbnh=96&tbnw=156&start=15&ndsp=18&ved=1t:429,r:14,s:15&tx=90&ty=40&biw=1138&bih=525