February 4, 2016: Our Daily Work

The beach in front of our Field Station is important.  Almost half of the leatherback turtles in the eastern Pacific nest here.  In the 1970s, 1980s, and 1990s nearly all the eggs were dug up by humans and eaten.  The beach was made into a national park in the mid-1990s and now volunteers and biologists patrol the beach every night from October through March when the turtles are nesting.  Our vigilance helps deter poachers.  It’s actually illegal for anyone to be on this beach at night, unless you’re an Earthwatch biologist, a professional guide or a park ranger or you are accompanied by one of those people.

Playa Grande by night. We are at work, but you can't see us. The lights in the distance are the town of Tamarindo.
Playa Grande by night. We are at work, but you can’t see us. The lights in the distance are the town of Tamarindo.

There are three species that nest here:  Leatherbacks, Olive Ridleys, and Black Sea Turtles.  The leatherbacks are really huge.

We walk in teams of three; one staff biologist and two volunteers.  We wear red headlamps but keep them turned off unless we find a turtle.  We wear long pants to protect against sand fleas and athletic shoes to protect our feet from injury in the dark and carry water, bug repellant and scientific equipment.  We start three hours before high tide and continue until three hours after high tide, no matter what time of the night high tide is.

We are divided into several teams; last night I was doing the “north” portion of the beach.  We walk briskly down the beach for about twenty minutes on the wet sand.  Then we sit still for twenty minutes.  Then we walk briskly back the way we came.  Another break.  Back and forth, back and forth, we crisscross the same portion of beach for six hours in twenty minute sweeps.  At the ends of our segment we occasionally meet other groups.  It’s both strenuous and contemplative, because it’s very dark and the stars are really bright.  There is phosphorescence in the water; bright specks of it are lying on the sand like little glowing jewels.  During our breaks we look up at the sky and see shooting stars.  The surf never stops.

We are looking for turtle tracks.  When the turtles crawl out of the surf, they leave a big dark track in the sand.  If we cross one, we follow it up the beach and find the turtle.  If she is laying her eggs in a good spot somebody lies down on the sand just behind her and counts the eggs as they fall into the hole she has dug.  If she is new to this beach, she gets a flipper tag installed.  If she’s not new, we read the tags she is wearing.

Doesn’t she mind all the attention?  It doesn’t look that way.  The biologists I am with say that she is in a “trance”; her body is flooded with egg-laying hormones.  We stay behind her, speak in hushed voices and use only red light which she can’t see well.  She appears not to notice us.

If she is laying her eggs in a “doomed” spot, we catch them as they come out of her and move them to the Hatchery.  The hatchery is a fenced-off square of sand high up on a dark, quiet section of the beach.  A person is minding the hatchery at all times of the night.  During the day we check every half hour in case baby turtles start to hatch.  When they do we put them in a bucket and let them go at the water’s edge that evening.  At night the job is to protect the hatchery from raccoons, who are always trying to come in and dig up the nests.

What makes a spot “doomed”?  For one thing, if there are lights nearby the baby turtles will try to crawl towards them when they hatch instead of down the beach towards the water.  They are programmed to crawl towards light near the horizon, because in a state of nature this would be the line of surf lit up by starlight.  Obviously, if there are lights from development nearby the turtles try to go to them and they never make it to the water.

Playa Grande by day is less mysterious.
Playa Grande by day is less mysterious.

Besides night patrols and hatchery shifts, a team patrols the beach every morning, starting just before dawn, to see if the night patrols missed any nests.  So there is almost always someone working on the beach, around the clock.  We get together for two meals a day, at 11:00 AM and 6:00 PM; these are the only times that nobody is working (except whoever is on hatchery duty.)

This project is the Earthwatch Institute’s longest-running project that is still in operation – it’s 27 years old.  But, the work we do doesn’t photograph well.  You can’t use a flash on the beach at night.

Tivon would like this place.
Tivon would like this place.

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