Female turtles lay their eggs in the sand, covering each clutch well to protect it after she returns to sea. The sun’s warmth incubates the eggs and shifting tides deliver fresh oxygen to the developing embryos. Disturbance of nests by poachers, predators and uninformed beachgoers can imperil eggs and nestling turtles.
Laws prohibit collection of sea turtle eggs in many countries, but poaching often continues in areas with weak enforcement. Costa Rican authorities allow local people to sell sea turtle eggs collected during the first three days of an olive ridley arribada (the Spanish word for a mass nesting of turtles) at the Ostional Wildlife Refuge.
Unfortunately, poachers also use this market as cover for sale of illegally collected sea turtle eggs, including critically endangered leatherback eggs.
Beachgoers are often unaware that walking above the high tide line or driving on the beach can crush nests and kill nestlings. Visitors pitching beach umbrellas in the sand to create shade on a sunny day may unknowingly penetrate turtle nests. Pet owners are usually unable to react fast enough to stop unleashed dogs from digging up turtle eggs.
Turtle eggs and nestlings are easy targets for predators with a strong sense of smell. But introduced species like domesticated dogs and cats are creating new threats to sea turtle nests along with natural predators, like coatimundis in Costa Rica.