August 12, 2008
Sea turtles are nesting on the seashore in record numbers
By JORDAN TOMBERLIN
Late one August evening, just a little north of ramp 43 in Buxton, 15
baby loggerhead sea turtles, each one smaller than the palm of your
hand, patiently awaited nightfall, when they could finally begin a long
and harrowing journey to maturity—a journey that few, if any of
them, would survive.
The hatchlings were found earlier that day, during routine
excavations of two hatched sea turtle nests, one in Avon village, and
one in Buxton, just south of Cape Point.
“You hope you don’t find these,” said Michelle Baker
Bogardus, lead sea turtle biologist at the Cape Hatteras National
Seashore, as she removed a live hatchling from the Avon nest during
excavation. “It usually means that they’re weak, but this
little guy is really energetic, so that’s a good sign.”
The Avon hatchling was joined by 14 other hatchlings from the much
larger Buxton nest, and just after the last rays of sunlight had
disappeared, the hatchlings were placed on the sand, one by one, and
began making their way toward the water.
Just minutes after hitting the sand, the turtles had to fend off one of
their most relentless predators—ghost crabs—which swarmed
the site in spite of the human presence, attempting to attack the
hatchlings at every opportunity. And they had to battle the surf, which
kept pushing them back on shore just as they were making progress.
Releasing the turtles directly to the water would seem like the nicest
way to let them go, but because turtles return to nest on the same
beaches they were born, they have to imprint the sand.
And as it turns out, getting to the water is the easy part. They have twice as much to worry about when they start swimming.
Their ultimate destination is the Sargasso Sea—an area miles out
in the Atlantic that has an abundance of sargassum, a kind of sea grass
that doubles as a place for the turtles to feed and a place for them
to hide. Turtles will spend years hiding out in the sargassum,
ostensibly growing and gaining strength, though, according to Bogardus,
we don’t really know what they’re doing out
“Their whole ability to survive really depends on them swimming
as far and as fast as they can,” says Bogardus. So, rather than
absorbing their yolk at a consistent, steady rate during their
incubation, sea turtles wait, absorbing the majority of the yolk a few
days before they hatch.
Then they use all that energy to hatch, crawl out of the nest, fight
off predators, and swim about 48 hours straight, until they reach
“Only about one in 1,000 hatchlings survive to maturity,
when they are able to give back to the population,” says
Bogardus. “And that’s putting it low.”
Loggerhead turtles are biologically designed to offset the low survival
rate. They generally nest every two years, and during a single nesting
season, each turtle comes to the shore every two weeks, laying and
average of four to five nests per season, each of which contains about
Still, that means that, even if all of the estimated 600 eggs that a
nesting turtle lays per year were to hatch, which is highly unlikely,
there might be one hatchling that will survive to replace it.
Given the difficulty of keeping a stable sea turtle population,
it’s not hard to understand why people are so excited about the
record number of sea turtle nests that have been laid on the Outer
Banks this year.
of Aug. 9, on Cape Hatteras National Seashore alone (which includes
Ocracoke, but excludes the Pea Island Wildlife Refuge or Cape Lookout
National Seashore), there were 106 confirmed nests and one dig—a
site where a turtle has almost certainly nested, but park rangers are
not 100 percent sure. Almost all were loggerhead nests. Three
were green sea turtle nests.
That’s the highest number of turtle nests on record for Cape
Hatteras, besting the previous record by seven or eight nests, and far
exceeding the 2007 nesting season, which, with 82 nests, was considered
a very good year. And because nesting season continues through
the end of August, it is entirely conceivable that the number of nests
could keep rising.
Not only are there more nests this year, they have, so far, all been very successful nests.
“Biologically, it’s just wonderful,” says Bogardus,
who, in spite of her expertise in the field, admits that no one really
knows what has caused the recent spike in nests and that it’s far
too early to begin picking out variables.
“There are so many things that affect sea turtles. So many
variables go into their nesting, that it would be premature to credit
just one thing,” she says.
Those eager to use record number of nests as evidence for the success
of the April 30 consent decree should consider that Pea Island Wildlife
Refuge, where beach driving, day or night, has been banned for decades,
is also having a banner year.
Last year, Pea Island produced 14 nests. This year, as of Aug. 4,
there were 23 confirmed nests on Pea Island, and, like Hatteras, the
distinct possibility of even more.
Cape Lookout National Seashore is reporting 92 nests and 13 digs, as of
Aug. 7, and several of the digs will probably turn out to be nests.
Seashore biologist Michael Rickard says he expect the year will turn
out to be close to average, which is about 125 nests.
And the entire state of North Carolina is doing really well.
According to Matthew Godfrey, senior turtle biologist with the North
Carolina Wildlife Resource Commission, the average number of North
Carolina nests, based on data from the past 13 years, is about 715. As
of now, he estimates a total of about 785 nests across the state.
Though the reasons behind the nest boom remain hazy for now, the
importance of North Carolina’s nests to the sea turtle population
are crystal clear.
While excavating the Avon nest, just a couple hundred yards south of
the pier, Bogardus pulled out a temperature gauge, which had been
placed in the nest to document the temperature during incubation.
sex of a sea turtle is determined by the temperature at which they
incubate,” she explained. Nests laid in cooler temperatures will
produce more males, while nests that incubate in warmer temperatures
will yield more females.
Because Cape Hatteras, located in a temperate climate zone, is the
northernmost boundary for nesting sea turtles, the nests here generally
yield more males, and since 90 percent of loggerheads nest on the
subtropical beaches of Florida, the success of the 10 percent laid on
other, cooler beaches to the north is crucial to the health of the
“Most people don’t know how important our nests are.
Without the male population produced here, the whole North Atlantic
population could be ruined,” Bogardus says.
It would be almost impossible to overestimate the fragility of sea
turtle eggs, and with so much riding on the success of these delicate
nests, the Park Service adheres to strict, often unpopular, management
practices to ensure the health and safety of every nest on the beach.
Each morning during nesting season, around 5 or 5:30, teams of park
rangers patrol the beaches looking for evidence of turtle activity.
When a nest is found, the site is carefully examined, roped off, and
closely monitored until it hatches—usually anywhere from 50 to 90
days after it’s been laid.
In the event that a nest must be moved, usually because it has been
laid close to the high tide line and is in danger of being washed over,
it’s done with the utmost care and precision.
“We measure the dimensions of the original nest, and then we bury
the eggs at the exact same width and depth that the mother laid
them,” Bogardus explained, as she continued to excavate the Avon
nest, which had been relocated closer to the dunes. “We try to
keep everything as natural as possible.”
The closures remain small until the nests reach day 50 of incubation,
which is the earliest date that the eggs could possibly hatch. At day
50, the Park Service expands the closure, roping off 175 feet on either
side of the nest and extending the closure all the way to the water.
Unfortunately, in the case of nests laid close to the dunes, which is
actually the best place for them to be, this results in an almost
complete beach closure.
The park also puts up a “filter fence” at day
50—black tarpaulin material, about two feet high, that surrounds
the nest and helps block out artificial lights, including bonfires,
which can disorient the turtles and jeopardize their survival.
Bogardus recently related the story of visitors to Avon, who were in
touch with her after they had a legal bonfire on the beach about 300
feet from a full beach closure for a turtle nest that had reached the
The filter fence extended to the high-tide line, but the turtles
hatched at low tide, and as they headed to the water and got beyond the
fencing, they were attracted to the bonfire and headed into the fire
pit. The visitors, Bogardus said, did the correct thing, scooping
up the hatchlings before they got to the pit and carrying them to the
The closures remain as such until three of four days after the nest has
hatched, when park rangers excavate the site to determine the outcome
of the nest and, perhaps most importantly, to rescue any live
hatchlings that, for whatever reason, didn’t make it out.
Until Sept. 15, beachgoers are permitted to walk or drive, in areas
where ORV use is allowed, behind these closures.
However, under the consent decree, any nest still in the ground that
has reached 50 days of incubation after Sept. 15 will automatically
become a full-beach closure—175 feet on either side of the nest,
from the dunes to the water—until the nest has hatched and been
excavated, which could take up to 90 days, though according to
Bogardus, most of the nests this year have hatched around day
As of Aug. 11, there are 14 nests that will reach day 50 on or after
Sept. 15, as well as 25 nests that will reach day 50 by Sept. 1 and
so will possibly still be in the ground by the Sept. 15.
According to Bogardus, a lot of these closures will not significantly
impact ORV access—some are in villages and others are in
protected areas— but several of them will affect access, mostly
on Hatteras Island. And several of the nests are near Cape Point
and could bring another closure of that area during the fall fishing
“The concern now is how many more nests are we going to get from
here on out. Those are going to be the problem nests for access,”
It will be a while before we know if the stricter requirements of the
consent decree will have any impact on the remaining nests. As Bogardus
has frequently pointed out, the survival of sea turtles and the success
of their nests depend on a mind-boggling number of variables.
“They’re mysterious,” she says. “Here’s a
creature that’s been around for 100 million years. They survived
whatever killed the dinosaurs…and it’s amazing to me that
we know so little about them.”
What Bogardus and others do know is that they will keep doing everything they can to protect these ancient, enigmatic animals.
And for now, at least, it seems that whatever they’re doing is working.