By
Jef Akst | November 1, 2012
In
2007, sea turtle researchers Kate Mansfield of the US National Marine Fisheries
Service and Jeanette Wyneken of Florida Atlantic University (FAU) were faced
with a dilemma. They wanted to track loggerhead turtles during the oceanic
phase of their lives, from the time they leave nesting beaches as hatchlings
until they move back to near-shore habitats some years later—but such young
animals were too small for the tagging devices used on adult turtles.
“It’s
easy to glue a tag on some of the larger turtles, but the first couple of year
age classes have been much too small,” Mansfield says. “So there’s this whole
gap in our knowledge of what turtles are doing, how they’re behaving, what
they’re eating, what part of the water column they’re swimming within. From the
time they leave the nest as hatchlings to the time they come back, there’s just
this huge unknown.” And given that all species of sea turtles are endangered or
threatened, understanding these early, vulnerable years is critical to managing
populations. “The more we know, the better we can protect them,” Mansfield
says.
Mansfield
had recently learned of smaller tags used on birds that took advantage of solar
energy technology to eliminate the large battery packs that power many
satellite tagging devices. “Sea turtles are basically birds with flippers,”
Wyneken noted. But attaching the tags to their small, semisoft shells was
proving difficult. The duo had tested a variety of tactics on Wyneken’s
lab-reared turtles at FAU, but nothing seemed to work. Affixed with the typical
marine epoxy glues used for larger animals, the tags fell off within 2 to 3
weeks due to the young turtles’ fast growth. Velcro was similarly ineffective.
An independent-study student in Wyneken’s lab who had started school as a
fashion design major before switching over to biology at FAU designed various
flexible neoprene harnesses, which worked, but all too well—they didn’t fall
off as the turtles matured, and started to constrict the animals’ shells as
they grew.
Then,
while mulling over the problem one day in the lab, Mansfield noticed Wyneken’s
beautifully manicured toenails, with blue waves carefully painted on. Wyneken
also thought of her guitar-playing husband, who had acrylic nails applied to
his own to help him pluck the strings. The researchers realized that turtle
shells are composed of the same protein as human fingernails—keratin. Maybe the
techniques the manicurist used could help them secure the tags to the young
turtles. Wyneken stepped outside and called Marisol Marrero of Just Nails in
Boynton Beach, who recommended they use the same acrylic base coat that she
used on Wyneken’s husband’s nails. So the two researchers buffed shells and
painted them with nail acrylic from the local pharmacy before gluing the tags
in place.
The
strategy worked. Previously, the longest time researchers had been able to
track a young oceanic turtle in the wild was a few days, and the best tags
Mansfield and Wyneken tested in the lab lasted just a few weeks. The new
technique “extended the attachment period by 4 to 8 times,” Mansfield says—up
to 2 months or more.
On
top of the acrylic base coat, the team was using a surgical adhesive to secure
the tags. Then another of Wyneken’s students, whose family owned a hair salon,
recognized the odor. “One of my undergrads said to me, ‘That glue you’re using
smells like what we use for hair extensions,’” Wyneken recalls. The student
brought in a bottle of the stuff to the lab, and sure enough, the hair
extension glue worked even better. “It’s the same chemical, but it polymerizes
a little differently, so it remains a little stretchy,” Wyneken says.
“Basically it accommodates, in people, the movement of the scalp, and in
turtles, the growth.”
In
2009 the team released several tagged turtles, some as small as 11 centimeters
long, into the Gulf Stream, and headed back to the lab to wait for the
satellite data to start coming in.
The
first batch of tags, affixed to animals 4–9 months old, lasted 38 to 172 days
(Mar Ecol Prog Ser, 457:181-92, 2012; manicurist Marrero is acknowledged in the
paper). On animals that have been released since then, the tags have lasted
more than 200 days.
“Considering
that prior to this work almost all of the tracking data were limited to a
couple of days [on turtles] from near-shore habitats, what we’re getting is
pretty exciting,” Mansfield says. “We’re seeing the turtles moving thousands of
kilometers in the Atlantic.”
The
ability to track younger turtles for extended periods of time in the open ocean
is promising for studying seasonal patterns of activity, migration routes, and
other aspects of turtle behavior. “It’s going to allow you to investigate the
spatial and temporal distribution patterns of a life-history stage that’s been
relatively understudied,” says marine scientist Mike Arendt of the South
Carolina Department of Natural Resources.
Mansfield
and Wyneken couldn’t be more pleased with their salon-inspired technology.
“It’s really worked out beautifully,” Wyneken says. “I’m reminded every time I
get a manicure.”
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