Scientists spend their nights tagging sea turtles
Published: August 29, 2011
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ST. CROIX - Melanie is a feisty one.
Even as biologists and interns struggled to keep the hawksbill turtle - which they have named Melanie, after the girlfriend of National Park Service biologist Ian Lundgren - contained in a movable "turtle corral" on Buck Island's north side late Friday night while they finished their work, Melanie wanted no part of it.
Like the untamed broncos and bulls at a rodeo, Melanie kicked up sand, tested the sides of the corral trying to find any weakness, and at one point, managed to mount the top of it with her front flippers in a daring bid for freedom and the sea, just a few feet away.
With soulful eyes, a countenance full of character, and a soft little nose that feels surprisingly similar to a dog's nose, Melanie seemed at times to accept the situation - or perhaps she was just gathering strength for her next attempt at escape.
The saturation turtle tagging project that the National Park Service and the U.S. Geological Survey are working on at Buck Island this summer is aimed at helping endangered turtles like Melanie survive by enabling researchers to learn more about where they go when they aren't nesting.
The information the three-year study gleans should help policymakers and others make smarter decisions aimed at better managing endangered sea turtle species, said Kristen Hart, a USGS research ecologist who is the principal investigator for the project.
Hart, who is based in Fort Lauderdale, Fla., was in the territory last week to deploy satellite and acoustic tags for the project on 10 sea turtles nesting at Buck Island.
On a small scale, the data on turtle movements will show where their critical habitats are - and actions can be implemented to better protect or manage those areas, Lundgren said.
On a larger scale, the project will show where the tagged turtles migrate to when they return to their foraging grounds, he said.
"If we know where they're living when they're not here, we can potentially develop partnerships to better protect them when we're not with them," Lundgren said.
The satellite tags will transmit locations when the turtle surfaces.
The acoustic tags will communicate positions, even if the turtle is underwater, with acoustic receivers that will be deployed around Buck Island Reef National Monument, Hart said.
While the first year of the study is focusing on satellite-tagging nesting turtles, next year, researchers will also attempt to deploy the tags on turtles that are caught in the sea, and then released.
For most of the past week, scientists and interns have been heading out to Buck Island nightly for the project, with a goal of deploying 10 satellite tags on sea turtles nesting there.
The project fits in nicely with another, long-term project the Park Service has been doing to identify all the turtles nesting at Buck Island, Lundgren said. Zandy Hillis-Star, chief of resource management for the Park Service's sites on St. Croix, started that project in 1989.
For that project, Park Service employees and interns spend their nights patrolling the perimeter of Buck Island during turtle nesting season, and anytime a turtle comes in to nest, they identify it.
Some, like Melanie, have already been tagged with an identification number, and they can record that she has come back.
Others are coming for the first time to Buck Island, and they are tagged with identification numbers before they head back out to sea.
The Buck Island nesting project has allowed the Park Service to see, over the years, what is happening with the sea turtle population that nests on Buck Island.
For instance, a population spike occurred in 2000, and biologists hypothesize that management actions taken 20 to 30 years ago - including ridding Buck Island of mongoose - may be responsible.
"As far as we can tell, the population is expanding, at least at this location," Lundgren said. "It's a good news conservation story."
He described it as "a really great project."
"It's enjoyable. And it's one of the few conservation success stories," he said.
Every year for the turtle nesting project, the Park Service gets help from four Student Conservation Association interns. There are also two Student Career Exploration Program biological science technicians helping out this year.
Elizabeth Armstrong at The Buccaneer has also helped the project along through the years by providing room and two meals a day for the interns who are working for the Park Service at Buck Island, Lundgren said.
On Friday, as the end of the day approached, a group working on the two projects headed out in a boat for Buck Island, where they would spend the night.
They disembarked and sprawled out on the pier as a base point, got their gear together, and had a bite to eat as the sun was setting.
As darkness settled in and the stars began to twinkle, a nurse shark meandered under the pier and glided by.
And then the patrols began.
Those patrolling the beaches use red flashlights, with a goal of not startling the turtles, as white lights do.
Everyone is connected by radio, enabling them to communicate when a turtle has come ashore to nest.
The rhythm of the waves lapping against the dock, the canopy of stars, fireflies twinkling among the trees higher on the island, and occasional spots of bioluminescence in the water make an easy backdrop for conversation as those who aren't on patrol wait for turtles to arrive.
They are not disappointed.
Around 9:15 p.m., a call comes in on the radio that a turtle is nesting on the north side of the island, sending everyone scrambling into action.
To get to where the hawksbill turtle, later named Melanie, has come ashore and is making her nest requires hiking along beaches and over rocks.
Melanie has gone into the bush and is digging away when everyone arrives.
There is a wait while she digs, followed by a flurry of activity, which includes identifying her and cleaning barnacles off her shell, while she lays eggs.
Typically, once sea turtles begin laying their eggs, they become focused only on that, Lundgren said.
While she is laying her eggs, the hawksbill turtle does not seem bothered at all when those gathered around identify her by the number on her tag, try to draw a blood specimen and begin cleaning barnacles off her shell, to make it easier to attach the satellite tag.
Then there is another wait while the turtle - which Lundgren and Hart have decided to call Melanie for satellite-tracking purposes - covers her nest.
Around 11:15 p.m., someone warns from the bush: "She's headed out!"
And everyone jumps into action.
Some man the turtle corral, a set of large plywood boards hinged together, with pipes in the corners that are used to anchor the pen into the sand.
As Melanie starts toward the water, Clayton Pollock, a Student Career Exploration Program biological technician, heads her off, and others set up the corral around her.
Melanie, apparently not happy with the situation, struggles at first.
"That's right, get it all out now," Pollock says, as he works with her.
Once Hart draws a blood sample, Pollock and Michael Cherkiss, a wildlife biologist with the USGS, begin preparing her shell for the small satellite tag that will go there.
A special epoxy, which does not heat up, is used so that it does not cause the turtle discomfort, Hart said.
Cherkiss paints a small area at the top of the shell with epoxy, then applies the tag. The epoxy needs 45 minutes to dry.
The smaller acoustic tag goes on after that, and then they wait while the epoxy dries.
By 12:45 a.m. Saturday, the entire tagging procedure is complete and the corral is opened.
Melanie seems unaware that the sea is beckoning for a moment, but she then darts toward it, splashing into the oncoming waves and disappearing into the surf.
After she is gone, Lundgren applies a bucket of white beach sand to the top of the nest, because the temperature of the nest has an effect on what gender the hatchlings will be.
According to past research on Buck Island, dark soil with no shade - like the area where Melanie made her nest - produces all females, Lundgren said.
By adding the sand, scientists hope the nest will produce a mix of male and female hatchlings.
The experience of working with sea turtles is a moving one at times for the interns.
"They're just such awesome creatures," said Ashley Hunt, one of the interns. "The fact that they're protected and endangered, it's great to be part of something like this."
Anyone can follow the movements of the turtles that are satellite tagged for this project by going to www.seaturtle.org/tracking/index.shtml?project_id=663 and clicking on a name.