This summary life history of sea turtles, an excerpt of the sea
turtle Sea Stats publication, includes information about age,
growth, and reproduction.
Read the Sea Turtle Sea Stats Publication
Sea turtles are among the oldest creatures on earth and have
remained essentially unchanged for 110 million years. However, they
face an uncertain future. Sea turtles are threatened in many ways,
such as encroachment of coastal development on their nesting
beaches, encounters with pollutants and marine debris, accidental
drownings in fishing gear, and international trade in turtle meat
Information about these ancient nomads of the deep has until
recently focused on nesting females and hatchlings because they are
the easiest to find and study. The advent of new research
techniques, such as satellite tracking technology, has allowed
scientists to peer into other phases of their lives. Florida, a
leader in sea turtle research and conservation, is home to the
nation's only refuge designated specifically for sea turtles. On
Florida's east coast, the Archie Carr National Wildlife Refuge,
named after the pioneering researcher (pictured to the right) whose
work first called attention to the plight of the sea turtles,
serves as a nursery for approximately one-quarter of all loggerhead
turtle nests in the Western Hemisphere.
Sea turtles are air-breathing reptiles remarkably suited to life
in the sea. Their hydrodynamic shape, large size, and powerful
front flippers allow them to dive to great depths and swim long
distances. After their first frantic crawl from the nest to the
ocean, male sea turtles never return to the shore again, and
females come back only long enough to lay eggs.
There are seven species of sea turtle: green turtle, hawksbill,
leatherback, loggerhead, olive ridley, Kemp's ridley, and flatback.
All but the olive ridley and flatback are found in Florida. Sea
turtles have long and narrow wing-like flippers in place of
forelimbs and have shorter webbed flippers as hind limbs; unlike
their terrestrial relatives, they cannot retract their heads very
far into their shells.
In most sea turtles, the top shell, or carapace, is composed of
many bones covered with horny scales or "scutes." Turtles are
toothless but have powerful jaws to crush, bite, and tear their
The smallest of the sea turtles are the ridleys, weighing in at
85 to 100 pounds as adults. Leatherbacks are the behemoths and can
grow to 2,000 pounds. Most sea turtles grow slowly and have a
life-span of many decades. Although sea turtles can remain
submerged for hours at a time while resting or sleeping, they
typically surface several times each hour to breathe.
In summer, an ancient reproductive ritual begins when the female
leaves the sea and crawls ashore to dig a nest in the sand. She
uses her rear flippers to dig the nest hole and then she deposits
about 100 eggs the size of ping-pong balls.
Fast Fact: Female sea turtles often appear
to be weeping as they nest; the main purpose for these tears is to
remove any salt from the turle's body.
When egg-laying is complete, the turtle covers the eggs,
camouflages the nest site, and returns to the ocean. Nesting
turtles may return several times in a nesting season to repeat the
process and usually nest every two to three years.
As is true for some other reptiles, the temperature of the sea
turtle nest determines the sex of the hatchlings. Warmer
temperatures produce more females, whereas cooler temperatures
result in more males. Consequently, conservationists prefer to
leave turtle eggs in their original location whenever possible so
that sex ratios are determined naturally.
Fast Fact: The contiguous beaches of
Brevard, Indian River, St. Lucie, Martin, and Palm Beach counties
are the most important loggerhead nursery areas in the Western
Hemisphere, attracting more than 15,000 female loggerheads each May
After incubating for about two months, the eggs begin to hatch.
A few days later, 2-inch hatchlings emerge as a group. This mass
exodus usually occurs at night, and the hatchlings use the bright,
open view of the night sky over the water to find their way to the
lights on beachfront buildings and roadways distract hatchlings
on their way to the ocean. Because of this danger, many beachfront
communities in Florida have adopted lighting ordinances requiring
lights to be shut off or shielded during the nesting and hatching
Unless noted otherwise, all photographs are
credited to the Florida Fish and Wildlife Conservation Commission
(FWC), Florida Sea Turtle Salvage and Stranding Network