Sea Turtle Migration

Michela DiBella

A green sea turtle in Hawaii.

Habitat and Diet (continued) They spend their entire lives at sea, except when adult females

come ashore to lay eggs several times per season every 2 to 5 years. After about sixty days, baby sea turtles (known as "hatchlings") emerge from their sandy nests and make their way to the ocean —attracted to the distant horizon. The juvenile turtles spend their first few years in the open oceans, eventually moving to protected bays, estuaries, and other near shore waters.

Each species relies on a different diet: greens eat sea grasses; leatherbacks feed on jellyfish and soft-bodied animals; loggerheads eat heavy-shelled animals such as crabs and clams; hawksbills rely on sponges and other invertebrates; and the Kemp’s ridley prefers crabs. 

Leatherback sea turtles can lay up to 90 fertile eggs per nest.

Facing ProblemsAs sea turtles migrate, sadly the face threats by humans

including accidental capture and entanglement in fishing gear (also known as bycatch),the loss of nesting and feeding sites to coastal development, intentional hunting (poaching), and ocean pollution.

Sea turtles are well-adapted to the ocean though they require air to survive.

Habitat and DietSea turtles live in almost every ocean basin throughout the

world, nesting on tropical and subtropical beaches. They migrate long distances to feed, often swimming across entire oceans. Some loggerheads nest in Japan and migrate to Baja California Sur, Mexico to forage before returning home again. Leatherbacks are capable of withstanding the coldest water temperatures (often below 40˚F) and are found as far south as Chile and as far north as Alaska.

One of the sea turtle routes for the loggerhead turtles.

Migration Migration habits differ not only among species but also among different populations of the same

species. Some sea turtle populations nest and feed in the same general areas; others migrate great distances.

Green sea turtle populations migrate primarily along the coasts from nesting to feeding grounds. However, some populations will travel 2,094 km (1,300 miles) across the Atlantic Ocean from the Ascension Island nesting grounds to the Brazilian coast feeding grounds.

Black sea turtles migrate along the coast from breeding areas to feeding grounds between the northern and southern extremes of their distribution range.

Loggerheads leave foraging areas and travel on breeding migrations that range from a few to

thousands of kilometers (1 kilometer = 0.62 miles).

Kemp's ridley turtles follow two major routes in the Gulf of Mexico: one northward to the Mississippi area, the other southward to the Campeche Bank, near the Yucatan Peninsula.

Populations of olive ridleys have been observed in large flotillas traveling between feeding and nesting grounds in the Eastern Pacific and Indian Oceans.

Migration (continued) Hawksbill migration studies have been limited. Evidence suggests that some hawksbill

populations show cyclic nesting migrations. Other researchers have documented non-migratory and short-distance migratory populations.

Flatbacks move from their nesting grounds on the northern coast of Australia and islands to feeding grounds in shallow waters of northeastern Australia. Distance covered ranges from 215 to 1,300 km (134 - 807 miles).

Leatherbacks have the longest migration of all sea turtles. They have been found more than 4,831 km (3,000 miles) from their nesting beaches.

Migration habits differ among sea turtle species. Migrations may range from a few to thousands of kilometers.

The most common method used to track free-ranging sea turtles is flipper tagging. Although this method yields information on migration destinations, it does not reveal travel routes.

Recently radio, sonic, and satellite tracking have been successful in monitoring sea turtle movements.

A new hatchling crawling to the ocean water.

Fun Facts About Sea Turtles- Many beachside residents in the United States are required, by law,

to douse their lights during nesting season. Scientists believe that hatchlings need to follow reflected moonlight and starlight to find the sea. If human light pollution dims nature's beacon, the hatchlings become disoriented and won't reach the safety of the ocean.

- In 1991, an estimated 610,000 Olive Ridley turtles nested in a single week on a beach in India.

More Fun Facts- Sea turtle populations are difficult to count because

juveniles and adult males do not come ashore.- Sea turtles (like other turtles) have no teeth, but the jaw of

each species is specifically designed for its food source.- Sea turtles hear vibration more than sound as we know it.

Their eyesight underwater is good, and they have an excellent sense of smell

Another green sea turtle in Costa Rica.

Resources http://www.seeturtles.org/43/sea-turtle-facts.html

http://www.seaworld.org/infobooks/seaturtle/sthabit.html

http://www.thejunglestore.com/Sea-Turtle

THE ENDThanks for watching!

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