Sea Turtles 101 | Nat Geo Wild

sea turtles are ancient mariners present in all but Earth's coldest oceans these marine reptiles are well adapted to a life on the moon sea turtles have existed since the time of the dinosaurs the earliest known marine turtle lived about 120 million years ago named Desmet ausellus paddle I it was six feet long and had the characteristic features of modern sea turtles including a carapace or top shell and paddle like limbs today there are seven species of sea turtles with the largest being the leatherback growing as long as eight feet and weighing up to 2,000 pounds it is larger than known fossils of its prehistoric ancestor the paddle I sea turtles can lay more than 150 eggs at a time called the clutch these large egg deposits help ensure the survival of sea turtle hatchlings once a female lays her eggs she returns to the sea leaving her hatchlings to fend for themselves fewer than point-1 percent of hatchlings survived to adulthood in part due to numerous predators on the beach emerging in large numbers increases the chance that some will survive a sea turtle sex is determined by temperature unlike most vertebrates a sea turtle sex is not determined by sex chromosomes instead the temperature of the nest determines the sex of the hatchlings when temperatures are warm at about 88 degrees Fahrenheit most of the hatchlings will be female but when temperatures are cooler less than around 82 degrees Fahrenheit most of the hatchlings will be male sea turtles use Earth's magnetic fields to navigate sea turtles have geomagnetic abilities which serve as an internal GPS the turtles have particles of magnetite a magnetic mineral in their brains the magnetite likely plays a role in orienting sea turtles to Earth's magnetic poles similar to a compass baby sea turtles imprint on the unique magnetic signature of the beaches where they hatch this magnetic map can guide them back to the same beaches several years later to lay their own eggs all seven sea turtle species are threatened with extinction once abundant sea turtle populations have dramatically declined in the past two centuries fishing is a major threat to sea turtles as they become caught in fishing nets as bycatch or accidental catch illegal harvesting of turtle eggs trafficking and turtle products and ocean pollution are also concerns however policies have been enacted to reduce bycatch protect turtle habitats and prohibit the killing of sea turtles and their eggs by continuing this kind of intervention humans can help stop the decline of sea turtles helping keep these ancient mariners in the world's oceans [Music] [Music]

Channel: Nat Geo WILD

Views: 229,072

Rating: 4.8542871 out of 5

Keywords: nat geo wild, national geographic, wild, wildlife, animals, nat geo, natgeo, science, discover, nature, documentary, turtle, sea turtle, turtles, baby, leatherback, PLNxd9fYeqXeamV13ttpA4RMGDY3tkKWbe, PLNxd9fYeqXeYQaV1z9-tWQXJBeq_s8hX9, Sea Turtles, turtles have existed, time of the dinosaurs, dinosaurs, ancient mariners, ancestor, adaptations, helped the reptiles, conservation efforts, conservation

Id: gbhlJ_M0mYU

Length: 3min 45sec (225 seconds)

Published: Sat Feb 23 2019