SAND AND SEA
COOL DUDES, HOT CHICKS
Temperature plays a vital role in the biology of sea turtles.
The sex of a sea turtle hatchling is determined by the temperature
of its egg as it develops during incubation. Scientists call
this phenomenon temperature dependent sex determination.
“Around 84 degrees Fahrenheit, a nest will produce 50 percent
female and 50 percent male sea turtles,” Guertin points
out. “If it’s cooler than that, you’ll be skewed toward males.
If it’s higher than that, you’ll be skewed toward females. The
moniker to remember is ‘cool dudes, hot chicks.’ ”
Temperature also determines the length of the eggs’ incubation
period. Nests that are laid during the cooler months
of spring will take longer to incubate than ones during the
hotter months of summer.
The length of incubation varies with each species. Since
they are the largest, leatherbacks have the longest period,
which is around 60 to 75 days. The loggerheads and the green
sea turtles incubate for about 50 to 60 days before they hatch.
LOOKING FOR SIGNS
During nesting season, scientists along the Treasure Coast
daily survey the beaches and closely monitor for sea turtle
activity. With a trained eye, they look for clues to piece
together what happened on the beach the night before. The
markings that sea turtles leave in the sand give them a good
understanding of whether they successfully laid a nest or had
a false crawl.
“Sometimes they have false nesting emergences,” says
Quintin Bergman, an environmental specialist for Indian
River County. “We get a lot of these instances when they hit
a sea wall, beach furniture or other human disturbances. So >>
OUR SEA TURTLES
sea turtles swim to
nearshore waters where
they live in reefs,
lagoons and bays.