JUDY WOODRUFF: Sea turtles have inhabited the oceans for at least 120 million years.
But they are now among the most endangered species on the planet.
John Yang has the story about an global effort aimed at saving them.
It is part of our Breakthrough reporting for our series the Leading Edge of science
JOHN YANG: Most people head to the beach for the sun.
In Costa Rica, we went as the sun was setting, and stayed into the night.
We were with a group of wildlife conservationists hoping to find sea turtles coming ashore to
lay eggs.
HELEN PHEASEY, Wildlife Biologist: And keep not in front of me, but sort of a little bit
behind me, just so that, if I see tracks ahead of me, I will be able to stop us and just
say, OK, there is something.
JOHN YANG: Bright lights spook the turtles, so we used a night-vision camera.
The search was hit-or-miss.
Turtles' ancient instincts don't always synch with human schedules.
We came upon this black turtle, a particularly skittish subspecies, just as she was heading
back into the waters of the Pacific.
These days, the odds are stacked against sea turtle survival.
Among the biggest threats?
Humans.
They encroach on their habitats and kill them for their meat and for their shells to make
jewelry, illegal worldwide, but still freely available.
And the threat exists even before they hatch.
Across Central America, poachers destroy more than 90 percent of sea turtle nests on unguarded
beaches.
Turtle eggs are considered a local delicacy and an aphrodisiac.
Eating them is so ingrained in the culture that poachers are almost never punished.
Less exotic animals here?
KIM WILLIAMS-GUILLEN, Conservation Biologist: That's right.
JOHN YANG: One possible tool in the fight against poaching has its roots thousands of
miles from the turtle's nesting sites, a farm in Michigan.
That's where conservation biologist Kim Williams-Guillen developed a way to learn more about poachers,
3-D-printed plastic decoy eggs with GPS trackers.
If a nest is poached, the decoy is scooped up, too.
KIM WILLIAMS-GUILLEN: One day, I was just walking around, and suddenly had an aha moment
of, what if we could track the poachers of the turtle eggs?
JOHN YANG: Williams-Guillen works for Paso Pacifico, a California-based group that protects
biodiversity in Central America.
Her inspiration came from some unlikely sources.
KIM WILLIAMS-GUILLEN: I have seen a couple similar devices used actually on TV shows.
So, in the TV show "Breaking Bad," there is one episode in which somebody puts a GPS tracker
on a barrel of chemicals.
There's another TV show called "The Wire."
And in one episode of that, there are two detectives who are putting a listening device
into a tennis ball.
JOHN YANG: In fact, the information from Williams-Guillen's decoy eggs could ultimately help law enforcement.
KIM WILLIAMS-GUILLEN: If you're deploying eggs on several beaches in a country, and
let's say they all end up going to the same neighborhood or the same block, then that
suggests maybe a very centralized network with a couple of really key players.
JOHN YANG: It takes Williams-Guillen's 3-D printer about 90 minutes to lay a decoy egg,
and then it's elaborately painted to look like the real thing, with the help of a Hollywood
special effects makeup artist.
The eggs go from the snowy fields of Michigan to the tropical forests of Costa Rica.
Wildlife biologist Helen Pheasey takes them from there.
She joined Paso Pacifico's project in late 2016 as part of her Ph.D. research.
It's her job to plant the decoy eggs, which takes us back to our nighttime beach excursion.
Three hours after our first sighting, we'd given up on seeing another one.
But on the way back to our cars, we quite literally stumbled upon an olive ridley turtle
digging her nest.
For 20 minutes, her hand-like rear flippers scooped away sand, crafting a chamber for
her eggs, and then...
Oh, there you go.
The turtle laid more than 50 eggs.
And, to demonstrate, Pheasey added an impostor.
HELEN PHEASEY: She has no idea it's there.
The poachers won't know it's there.
And so we have got a nice little decoy hiding in there, tracking away, waiting to see where
they take them.
So -- and it's a very, very mixed feeling when you see the eggs move.
On the one hand, you're like, yes, they're moving, they're working, like, damn it, someone's
stolen the eggs.
Like...
JOHN YANG: And how does the information help fight poaching?
HELEN PHEASEY: So, the moment we know that the eggs leave the beach, we know that they
end up in the market.
What we don't know is what's going on in the middle
JOHN YANG: Later, Pheasey showed us the decoys' electronic trail, using one she carried with
her.
And what specific information is it telling you?
HELEN PHEASEY: OK, so the name of the egg I have given it, the date and the time that
it was at that location, and then the mileage.
So, we can start to get an idea of, like, not only where they're going, but how fast
they're moving, what type of vehicles they're using.
JOHN YANG: But you have had cases where poachers -- or at least there's indications from the
movements that the poachers have found the decoy eggs?
KIM WILLIAMS-GUILLEN: Everybody's going to find them at some point.
JOHN YANG: Right.
KIM WILLIAMS-GUILLEN: Somewhere along the trade line, they're going to find them.
We did have occasion where we actually tracked the egg, and the final point where it like
transmitted a signal was from in the middle of a riverbed.
(LAUGHTER)
JOHN YANG: Liza Gonzalez, Paso Pacifico's Nicaragua director, was initially skeptical
about the decoy idea.
The first time you heard this suggested, what was your reaction?
LIZA GONZALEZ, Paso Pacifico: Well, I think, you're crazy.
I think that not going to happen.
How you can do that?
But, you know, Kimberly, she work again with the artist, and she did it.
She did it.
Absolutely, it was so good, yes, and I would say, oh, my gosh, you are a genius.
Yes.
JOHN YANG: To learn even more about the poachers, Pheasey sends locals to buy eggs, so she can
sample their DNA.
HELEN PHEASEY: You have got like a salsa, kind of a chili salsa.
JOHN YANG: And this is how people eat them?
HELEN PHEASEY: Mm-hmm.
Yes, they knock them back with beer or alcohol of some sort.
JOHN YANG: So, you're trying to determine what species these eggs are?
HELEN PHEASEY: Yes.
What I want to know is what species laid the egg and which population did that species
come from.
If we start getting a load of eggs from that same population, we know that there's a serious
poaching problem going on, on that beach.
And that's where we can say, OK, we need to target law enforcement now, or we need to
get a conservation project up and running that patrols the beach.
JOHN YANG: Activists say the patrols are crucial.
The night we visited this community, there was a meeting with police, prompted by the
recent discovery of a dead turtle apparently killed for her eggs.
Marlon Mora Vargas was there.
He was a fisherman for more than 20 years and is now part of a regional network trying
to save sea turtles.
MARLON MORA VARGAS, Former Fisherman (through translator): The people know that it's an
endangered species, that it shouldn't be done.
They just don't want to change.
That's why we're working with kids, because they can change.
They can learn.
They can take new ideas, make a generational change.
My kids know turtles.
They have gone to see births of turtles.
They want to be in the beaches with me.
I show them the species that exist, what they shouldn't do.
JOHN YANG: Liza Gonzalez's daughter, Ashley Hodgson, is studying Marine biology, a second-generation
sea turtle defender.
ASHLEY HODGSON, Studying Marine Biology: They have been in the earth for thousands of years.
They can survive through all these changes.
And right now, they are in the stage when they can't change anymore.
Like, they can't survive anymore, and they need our help.
LIZA GONZALEZ: And I am very happy that you are doing this too.
JOHN YANG: Your daughter seems to have captured this passion as well.
LIZA GONZALEZ: Oh, yes, thank God.
She is the one that decide to help me in this subject that I have to protect biodiversity.
JOHN YANG: There's a big emphasis on outreach to young people.
Local children watched as newly hatched sea turtles were released and made their way to
the ocean.
The turtles were born earlier that day and kept safe until after dark to protect them
from birds and the scorching heat.
Conservationists hope that, among these kids, there's another Ashley Hodgson.
ASHLEY HODGSON: My plan is to save sea turtles.
(LAUGHTER)
ASHLEY HODGSON: I know that's an ambitious plan, but I think, if we work together, we
can get the goal.
JOHN YANG: And they believe these decoy eggs from Michigan will help them get there.
For the "PBS NewsHour," I'm John Yang on the Pacific coast of Costa Rica.