July 21, 2009

In the wee hours of summer mornings, somewhere between the night owls hitting the hay and the fleet leaving the docks, the quiet beaches of the Outer Banks play host to an ancient ritual—adult female sea turtles coming ashore to nest.

During the nesting season, which begins late in the spring and continues until around the end of August, sea turtles crawl ashore, dig large cavities in the sand with their back flippers, and lay their nests that can contain as many as 120 eggs.  Then they take a much-deserved siesta and head back to the water.

Laying a nest takes turtles around two-and-a-half or three hours,  and most nesting turtles will repeat the ritual as many as five times in a single season.

As busy as the nesting season is for the turtles, it’s probably just as busy for the National Park Service employees and volunteers, who are charged with the daunting task of finding, protecting, and monitoring each nest and its hatchlings from the beginning of the season until the last hatchling starts swimming.

Each morning during the season, Park Service employees patrol the beaches, looking for any sign of turtle activity.

They leave around 5 a.m. from Ramp 43 in Buxton. One person heads north, patrolling the 16-mile stretch toward Ramp 30, and two head south, covering the 18 miles between Ramp 43 and Hatteras Inlet.

A few weeks ago, I had the opportunity to accompany Michelle Bogardus, the lead sea turtle biotechnician for Cape Hatteras, on her morning patrol and see just how much goes into protecting these crucial nests.

On June 24, I met a bleary-eyed Bogardus, who had been up until about 1:30 that morning watching a turtle lay a nest just a few steps north of Ramp 55 in Hatteras.

Before the sun had risen, we were off on the 36-mile round trip to Hatteras Inlet and back. 

“You’re looking for something made by a 300-pound animal,” Bogardus explained as we headed toward the Cape Point, “so you can imagine the impressions are pretty deep.”

But it was my first patrol, so every print in the sand looked like a turtle track to me.

Luckily, I got several chances to see the real thing that morning—two loggerhead nests, one between Ramp 45 and Ramp 49 in Frisco and the one Bogardus had seen at Ramp 55, as well as one false crawl. 

As it turns out, turtle tracks are unmistakable, but that doesn’t necessarily mean they’re easy to spot.

Though the tracks themselves are highly distinctive, they can get lost in the sand—erased by incoming tides, buried by tire tracks, or camouflaged by footprints. 

The Frisco nest was the first one we found that morning.

Based on the tracks, which led to and from a large mound of sand just above the high-tide line, Bogardus determined it had been laid relatively recently, probably around 3 or 3:30 that morning.

But since the nest had been laid in a protected area and since Bogardus knew for sure that there was at least one more nest that needed to be marked off in Hatteras, we continued the run.

No more than a quarter mile south of the first nest, we stumbled upon another set of tracks, but there was no evidence of a nest. 

Many times, turtles will come ashore, and sometimes even begin digging a nest, but they will abort the attempt before laying any eggs, leaving behind what gets recorded as a false crawl.

Some management practices attribute all false crawls to disturbances, but according to Bogardus, we really have no way of knowing for sure why a turtle abandons a particular nesting attempt.

It could be any number of factors—from the location of the site to the texture of the sand.

In the case of the false crawl in Frisco that morning, it seems the turtle ran into a small tide pool that had gathered in a dip in the landscape.

“It’s not a disturbance,” she said.  “[The turtle] just ran into water again and didn’t know what was going on. The most likely scenario is that the false crawl belongs to the same turtle that laid the nest.”

We continued south, rounding the tip of Hatteras Inlet, but found no other signs of turtle activity that morning, save the Ramp 55 nest.

 And according to Bogardus, that was probably a good thing.

“Spits and inlets are really crappy places for nests,” she explained. 

Because the sand is constantly shifting in those areas, there really isn’t a “safe” location for the nests, and if the water table rises, water can inundate the nests from beneath the sand, causing severe damage.

So, we went back to Ramp 55 to begin the process of closing the nest area—which requires quite a bit more work than just sticking up some signs and string.

When a nest is suspected, the first task is to dig through the sand and locate the eggs, to make sure it’s actually a nest.  This can be a tedious and time-consuming task.  The eggs are buried deep, and there is a large area of sand to sift through before you can get to them.

Also, it’s hard to overestimate the fragility of sea turtle eggs, so to avoid damaging them, digging has to be done slowly and deliberately, using the side of the hand rather than the fingertips and gloves must be worn at all times.

Fortunately, since Bogardus had personally watched the turtle lay this particular nest, she had a fairly good idea of where to dig, which sped the process up enormously.

When the clutch is located, the nest is confirmed.

Before the eggs are covered back up with sand, a small temperature gauge is deposited in the nest to monitor the sand temperature.

Because the sex of sea turtles is determined by the temperature at which they incubate (warmer temperatures produce more females, while cooler temperatures produce more males), the temperature gauge is used to help ascertain the sex ratio—which is pretty important when you consider that the Outer Banks is the northernmost nesting grounds.

Because of the temperate climate, as opposed to the sub-tropical climate of Florida where 90 percent of loggerhead nests are laid, our beaches yield more males, and the success of our nests is critical to maintaining the health of the species.

After the nest is reburied, the site is documented, roped off, and raked over.

In order to make sure the nest can be located no matter what, GPS coordinates are collected and recorded, and an orange transponder ball is buried about two feet in front of the nest.

In addition, a small metal stake is placed just to the left of the nest, with larger PVC stakes, in direct alignment with the nest, extending all the way back to the dunes.

If, after exhaustive digging, no eggs are discovered, the site is either documented as a false crawl, in which case the tracks are raked out to avoid any confusion the next morning, or, in very rare cases, it’s considered a dig—a site where, though no eggs can be found, a nest almost certainly exists—in which case, the area is treated as a nest and monitored very closely.

After we finished the Ramp 55 nest, which, even with two sets of hands took a good 15 minutes, we headed north to Frisco to close the nest we had found earlier that morning.

We arrived at the site, put on our gloves, and started digging through the mountain of sand that covered the nest, looking for the eggs. 

It was not as easy as it had been in Hatteras. We didn’t know where to look, and there was a lot of ground to cover.
 
But, just when I thought my arms were going to fall off, Bogardus found the clutch, about 32 centimeters—a little over a foot—beneath the surface of the sand.

Now there was another problem. 

The nest had been laid uncomfortably close to the high-tide line, leaving it susceptible to overwashing, which can destroy it.

After much consideration, Bogardus made the difficult decision to relocate the nest a few yards back from its original site.

In and of itself, relocation is not a bad thing.

Quite the contrary, “It is an excellent tool that we can use as a means to help out a species that’s in trouble” says Bogardus.

But, it’s kind of like emergency birth control—it comes with its own set of risks, and you’re not supposed to use it all the time.

There are some pretty good reasons not to move nests. 

To begin, the eggs themselves are incredibly fragile, and the stress from the move can negatively impact their survival rate. 

On top of that, when the eggs are moved to a new nest, the sand composition is altered, which can affect egg health as well as the sex ratio of hatchlings.

And, in addition, there are studies to suggest that those hatchlings are less fit, making their already-low chance of surviving the 48-hour swim to the Gulf Stream even lower.

As a rule, the Park Service makes every effort to keep their management practices as natural as possible, but the ultimate goal, of course, is to protect the nests.

So, in those cases where the benefits outweigh the risks—which, according to Bogardus, has been about 30 per cent of cases so far this season—the nest is relocated.

Relocation is a tedious procedure, and everything has to be done with the utmost care and precision.

After some initial measurements are taken, the first task is to remove the eggs, one at a time, and place them in a cooler for transportation to the new site.

“You cannot tilt the eggs at all,” Bogardus instructed as she handed me the first egg—which was slightly bigger than a ping-pong ball, but much more flimsy. 

“They have to stay in the same position that they were in the nest.”

Admittedly, I was very nervous.

But, 119 eggs later, the nest had been successfully emptied.

Before covering up the hole, Bogardus took a few big handfuls of sand from the bottom of the nest to add to the new one.

She explained that the sand contained fluids left behind when the female laid the nest that could potentially help the hatchlings in their new home.

Next, the exact dimensions of the nest were measured, and a few yards directly back from the original nest, Bogardus began digging a new cavity, in what she described as “an upside-down light-bulb shape,” that matched the size of the original nest.

Once she had dug the nest, the eggs were gingerly placed inside, again, one at a time, in the exact same order in which they had originally been laid.

The whole process has to be done as quickly as possible to minimize stress on the eggs, without sacrificing anything in meticulousness—it’s a lot of responsibility.

And while Park Service employees and volunteers do everything they possibly can to ensure the health and safety of each nest laid on the seashore, the turtles don’t always make it easy for them.

Every year, there are difficulties—nests that must be moved, hatchlings that must be excavated, and nests that are lost to storms.

But there are always a few pleasant surprises, too.

So far, one of this year’s biggest surprises has been the unconventional story of a leatherback nest in Frisco.

For the most part, turtle nests are laid very late at night or early in the morning.

But in the middle of the day on Sunday, June 28, a female leatherback turtle came ashore about a mile south of the Frisco Pier, crawled about halfway up the dunes, and started digging a nest while about five or six people looked on.

It’s only the second leatherback nest that’s been laid in North Carolina this season. The first was laid in Kill Devil Hills, and, according to Bogardus, it’s probably the same turtle that laid both nests.

Not only is it a little late in the leatherback nesting season, but “She laid the nest in just a really crappy place,” Bogardus said.

That area was hit pretty hard by Hurricane Isabel in 2003 and is around the location of what’s now known as the Isabel Inlet.

According to Bogardus, the sand that was used to close the inlet was brought in from offshore, giving that area a less than favorable composition for nests.

Not only that, but at the time the nest was laid, there had been a threateningly high full-moon tide.

Fortunately, Bogardus said she is happy to report that the nest is doing much better, with about 15 more feet added in front of it on the beach.

Another pleasant surprise this season has been the high number of nests.

While it’s not sound science to compare this year’s numbers to last year’s record-breaking season—sea turtles nest every other year, so it’s a whole new crop of turtles nesting right now—Bogardus says the seashore is right on par with the numbers from last year.

As of Friday, July 17, there are 71 nests on the Cape Hatteras National Seashore, including 21 on Ocracoke—all loggerheads with the exception of the leatherback nest in Frisco. 

Last year on the same date, there were 75 nests.

“It’s kind of strange because it’s a totally different group of turtles,” Bogardus said, “but hey, we’ll take it!”


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If you see a nesting sea turtle or hatchlings

What should you do if you see a nesting sea turtle or hatchlings?

According to the National Park Service, you should  stay back at least 100 feet for nesting females and 30 feet for hatchlings so that you do not disturb them. Turn off all lights and do not use flash photography. Call the park so that staff can protect the turtles at 252-216-6892.

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