(Originally published in Costa Rica Outdoors )
“Do you think we’re going to get more rain?” Kim asked with a touch of dread in her voice.
From my bright-blue plastic chair in the open-air palapa, I turned and peered into the soggy evening before answering her question. “I’ve been told that lightning bugs are reliable indicators of rain; the closer they are to the ground, the sooner we’ll be getting rain.”
With keen attention, we eyed the twinkling fireflies that – to our collective discontent – hovered inches from the grass line. “When I walked here fifteen minutes ago, they were three or four feet higher,” I added. Kim Tomczak and Nick Dodrill, volunteers for Pretoma’s 2009 sea turtle project, studied the ground-level placement of the lightning bugs.
Moments later, the heavens opened and baptized Playa San Miguel, Costa Rica with an additional downpour. Stingers of lightning crackled perilously close, while rumblings of thunder answered almost instantly. Francisco Javier Garcia Fdez de Valderrama – better known as Fran – the 2009 site coordinator for the Playa San Miguel station, eyed the clock then questioned the others, “Is Wilson still out there?”
Wilson Vargas, a native of the area, was finishing the early shift, and we were taking the reins for the next one. Not only would we be guardians for the female olive ridleys that came ashore to nest, but we would also be releasing almost 100 hatchings into their original ecosystem.
There’s something magical about watching the innocent hatchlings’ intricate lessons of life. Guided by primal forces, the baby sea turtles tunnel from their nests and answer the ageless call of the ocean. They begin an arduous trek to the silvery waves that beckon from the inky darkness of the night. Like a lighthouse, the waves guide the parade of hatchlings to the giant ocean that will be their home for the rest of their lives.
On this particular November night, the unstable tropical weather tormented the southern zone of Guanacaste with the ugliest storm many had seen in years. Rain gushed from the rooftops; lightning popped, and thunder rumbled – way too close for our comfort. One strike sizzled, and thunder answered a split-second later. Kim sat a bit straighter; her eyes opened a bit wider.
Another flash popped even closer and extinguished the power with a hair-raising discharge of energy. The entire peninsula seemed cloaked in darkness as we groped for our flashlights. The catharsis of the intense lightning storm purged the heavens. Our eyes adjusted to the darkness, and we prepared for our next three hours on the beach. Armed with red-tinted flashlights, sea-turtle sized calipers, waterproof field journals, writing pens, measuring tapes, walkie talkies, and the apple-green bucket of precious baby turtles, we donned raincoats and stepped into the liquid darkness.
Kim and Nick took the southern route while Fran and I trudged north. (Playa San Miguel is 3.2 kilometers from end to end.) The absence of electricity cast an enchanting spell, and we stepped into a surreal darkness that removed all traces of modern man. We viewed the ideal setting that sea turtles require for completing their cycles.
The phosphorescence of the crashing waves bathed the seascape with an ethereal beauty. With no conflicting lights, I understood why the brightness of those waves plays such a critical role in the sea turtles’ survival.
As we walked northward along the rain-packed beach, Fran – whose home is Madrid, Spain – shared data about the olive ridley sea turtles. (Lepidochelys olivacea) The olive ridley’s first day of life is a brutal one; most perish within the first few hours. The survivors beat the odds against greedy predators on sand and in the water. Danger threatens as each step takes them closer to the water. Crabs, birds, raccoons, fish, coyotes and even jaguars feast on the tiny hatchlings. Ravenous fish await in the shallows and in the depths. Patrolling sea birds soar overhead. The survivors feed on plankton and algae then add crustaceans and mollusks to their diet as they get older. The females reach sexual maturity in ten to twenty years and can live to be 50 or 60.
Sharks will eat some of the adults, but modern man is the greatest threat. Many commercial fishing fleets, using illegal nets and lines, leave a wide swath of dead fish, rays and turtles. Lights that dot the shore and hillsides can confuse and avert the females from their beach of origin. Once ashore, a solitary nesting female can be spooked by people, lights and animals. Aborting her intent to nest, she might bolt to the ocean in dysfunctional panic and release her eggs in the water. Others complete the cycle, dig their nests, lay approximately 80 eggs, camouflage the hole, then return to the sea.
Olive ridley eggs hatch in 40 – 60 days. The sex of the hatchlings depends on soil temperature; eggs closest to the surface will become females if the soil temperature is over 28-degrees C (82F), while males develop deeper where the temperature is below 28-degrees C. A female might breed and nest up to three times during the mating season, which stretches from June until December along Costa Rica’s Pacific coast.
Olive ridleys are one of two species of sea turtle known for their “arribadas” (mass arrivals) that occur at unpredicted times on certain beaches. Costa Rica is one of seven countries in the world known for this phenomenon. When an arribada occurs, the female olive ridleys come ashore by the hundreds and sometimes thousands, depending on the beach. The numbers are declining at alarming rates because of poaching, beach developments, light pollution, and casualties from commercial shrimp nets. Twenty or more years ago, locals witnessed hundreds of sea turtles at Playa San Miguel. Wilson’s father remembers when there were thousands.
Now the nightly hope is for a few turtles. Poachers dig and sell the eggs like their grandfathers did when turtles were plentiful. The popular belief that consuming turtle eggs increases one’s libido ensures a market for illegally-gathered eggs.
Certain areas now allow the legal harvest of eggs during the first hours of an arribada, since many of those nests would be naturally destroyed by other turtles. Since prehistoric times, sea turtles have navigated by the rhythms of nature and by the radiance of the moon and stars. Thrown into an unnatural setting of light pollution, sea turtles are spooked and often confused by bright security lights and the more-subtle lighting of area homes and businesses. The lights also disorient the hatchlings, that crawl toward the brightest light on their horizon. Using Fran’s turtle-friendly red light, we watched the hatchlings crawl from the bucket and begin their journey to the ocean.
At a surprisingly brisk pace, the little tanks of energy alternated their front flippers as their rear ones propelled them closer to the ocean. Fran stressed how artificial lights have disrupted the delicate ballet that has been practiced and perfected since ancient times. With ease, he illustrated his point. Standing behind the line of marching turtles, he switched his headlamp from red to its normal setting. His became the brightest light in the area. The subtle light of the waves forgotten, the baby turtles turned and began an uphill trek to the new light source. Slowly Fran led the ‘herd’ – that’s how they acted – into a 180-degree turn, and once again they faced the ocean. He switched off the light, and the hatchlings resumed their journey to the sea.
With clarity I understood the importance of the communication between the waves and the turtles; the waves guide the hatchings to their rightful place in our environment. With drastic suddenness, the sea turtles’ decline illustrates the fragile balance between civilization and Mother Nature. Ignoring the attitudes of society, the olive ridleys follow their own voices. Picture a tiny hatching, the ridges of its cool gray shell barely catching the diffused light of the evening as it scoots towards the sea. It pauses and nudges the sand with its nose. Perhaps it’s imprinting the unique aroma of that particular spot; perhaps it’s taking a GPS position; alternating right flipper with left one, it stops again to rest, looks toward the waves then continues. It ignores the other nestlings, though all replicate the almost-identical dance. At times one increases its speed while another all but collapses with fatigue. Some nose the sand and hump their bodies in a hiccup sort of imprint, then proceed. Some veer a bit right or left, then quickly adjust and continue toward the beckoning waves. The wet sand near the water triggers an urgency, an excitement. They seem to rejoice in finding home. They imprint again and march onward toward the crashing surf. The waves race across the sand and stretch to greet the approaching turtles, then teasing like a siren, retreat.
The hatchlings follow the song of the ocean. They scuttle across the glistening water-soaked beach. Another wave arrives with enthusiasm; it breaks and rolls hurriedly toward the tortugitas. With a powerful greeting, the wave embraces then hurls the babies back toward their starting point; they somersault, twist and tumble as they are propelled backwards and dumped high and dry on the beach.
Mother nature doles out hard lessons. Like programmed robots, the tiny tanks regain their bearings and resume their march. Baptized with their first taste of life-sustaining water, they strive to reach it again. They resume their dance, using straighter routes while stopping sporadically to imprint the particular uniqueness of their beach. Ruthless, Mother Ocean disciplines her newest children again. Her lessons prepare them for the cruel world they are about to encounter. The hatchlings continue their ocean quest. At the mercy of the waves, they are propelled backwards then swept towards the depths. Their darkened wet shells reflect little light. They blend into the darkness and gain one advantage against unseen predators, and the ocean finally accepts them with tenderness.
The turtles’ little flippers launch them quickly into deeper waters. In un-synchronized timing, their tiny heads bob to the surface, then quickly submerge again as they advance into the depths of the sea.
Predators gobble many of the hatchlings as soon as they’ve gained their swimming badges. Others instinctively know to pull their flippers tightly against their bodies when danger lurks. Resembling a floating leaf, they have outsmarted the predator. One out of 1,000 will survive to see adulthood. Others predict the figure is closer to one out of 2,000.
Those few surviving turtles will return in a dozen or more years to continue the cycle as an adult. They’ll leave their favorite vacation spots from hundreds and thousands of miles away and return to their own precise GPS point on the planet. They’ll emerge from the sea, nudge the sand and bask in the familiar uniqueness of the homeland they left long ago.
Will modern man frighten them with artificial lights that say, ‘Go away! we are here!’ or will they be embraced to more-sensitive red lights that declare, ‘Welcome back!’?
Will they join thousands of turtles for an arribada? On most beaches, probably not.
Will they join hundreds? One can hope.
Will there be fewer? The numbers continue to drop.
At Playa San Miguel, ten females in one night is considered a lot.
One day will we view a Lonesome Georgette? Hopefully we’ll never witness such a sad moment.
Could we change our association with ‘red-light district’ so that it represents community pride and support for the sea turtles? We can hope.
Why not pull together and give the sea turtles a proper, “Welcome home!”?
It can easily start by changing a few light bulbs.