Sea turtles have lived on our planet for more than 110 million years, but today only seven species remain. They're divided up into two family groups. The first family includes leatherback turtles and the second one includes six species of hard-shell turtles. Sea turtles spend almost all of their lives at sea, except for short times every several years when females come ashore to lay eggs.
Young sea turtles are born on land and head for the sea as soon as they hatch. This period is the most dangerous time for them because birds, crabs and mammals, including foxes, dogs and raccoons, eat most of the young before they reach the water. Those that do make it to the ocean hide in sargassum seaweed. Even so, fish eat many of them. Only one in 1,000 babies makes it to adulthood, according to See Turtles, a non-profit organization that connects tourists and volunteers with sea turtle conservation projects.
Humans are the biggest threat to sea turtles. Thousands of sea turtles are killed by the fishing industry every year when they're caught in nets and thrown away as bycatch or when their habitats and food supplies are impacted by those nets. In addition, turtles are killed and traded for their leather, meat and oil or used to make jewelry and other craft items. Sea turtle habitats are also destroyed by coastal development and boat traffic. Turtles also die when they mistake plastic bags for food. According to the Sea Turtle Restoration Project, autopsies of leatherback turtles found plastic in their gastrointestinal tract 34 percent of the time. As of April 2011, human activity is responsible for six of the seven sea turtle species being classified as threatened or endangered.
Tiger sharks have been known to eat many strange items, including rubber tires, tar paper and chicken wire, but their normal prey consists of fish, squid, crabs, lobsters and sea turtles. Tiger sharks usually feed on the bottom or around reefs. Their large mouths and stomachs are adapted for eating large prey, and they can easily bite through the shells of big sea turtles with their knife-like teeth. In tropical and sub-tropical waters, turtle remains account for 10 to 36 percent of the stomach contents of sharks that were examined.
Orcas, or killer whales, are actually members of the dolphin family. They are called "wolves of the sea" because they hunt cooperatively in groups, like packs of wolves. In addition to eating seals, fish, seabirds and dolphins, orcas hunt sea turtles. Their teeth are designed for ripping and tearing, not chewing. Orcas consume about 550 pounds of meat every day.
- The State of the World's Sea Turtles: Threats
- St. Monica School The Sea Project: Sea Turtles
- SeeTurtles: Baby Sea Turtles
- The State of the World's Sea Turtles
- National Oceanic and Atmospheric Administration: Feature Shark - Tiger
- Sea Turtle Restoration Project: Plastic: Another Enemy To The Leatherback Sea Turtle
- Photo Credit Jupiterimages/Photos.com/Getty Images Hemera Technologies/Photos.com/Getty Images Tom Brakefield/Stockbyte/Getty Images
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