Sea Turtles
W
By Jane Iwan
46
hile there are seven
species of sea turtles,
the vast majority
of those nesting
on Kiawah Island are loggerheads,
named for their exceptionally large
heads. Occasionally green turtles and
leatherbacks have nested here but it is
uncommon. Their carapace length is
typically 2.5 to 3.5 feet and their adult
weight is between 155 and 375 pounds.
The United States Federal Endangered
Species Act lists the loggerhead species
as threatened. Their greatest threat is
the loss of nesting habitat, resulting
from coastal development, predation
of nests, and human disturbances, such
as coastal lighting, that disorient the
hatchlings.
Loggerheads feed primarily on
shellfish that live on the ocean
bottom, easily crushing them with
their powerful jaw muscles. They are
generally found in waters that extend
over continental shelves, coastal bays,
and estuaries. In the first 3 to 5 years of
life, sea turtles spend most of their time
on the open seas floating in seaweed
mats. They swim from our southeast
Atlantic coast into the circular North
Atlantic current that flows into the
Sargasso Sea. Between 6 to 12 years
later, they will return to the North
American coastline.
For years scientists have been
researching how sea turtles return to
their birthplace to lay eggs. Earlier
studies showed that sea turtles use
Earth’s magnetic field to guide them
at sea, but scientists were not sure
how magnetism could guide them to
their nesting sites. To determine this,
Naturally Kiawah