Sea Turtles: Promises and Threats
To glimpse any one of the sea turtles who nest in Costa Rica is an inspiring experience. All are magnificent, mysterious creatures with distinct qualities: the astonishing arribadas of the olive ridley; the impressive strength of the loggerhead sea turtle; the nimble maneuvers of the green turtle/pacific green turtle; the gorgeous colors of the hawksbill sea turtle; and the gigantic hulk of the leatherback turtle. All are fascinating.
But these graceful giants are in grave danger.
The global populations of sea turtles are declining at an alarming rate. Hawksbill global population, at about 8,000 nesting females, is one of the most frightening scenarios. The hawksbill’s population has been cut by more than 80% in just 100 years. The other sea turtle numbers are not as low, but all are in the tens or hundreds of thousands. Consider that their populations used to include millions and millions of sea turtles. These creatures are not doing well.
The reproductive rates of the turtles are slow, so it is difficult for them to recover from slaughter by poachers and fishermen. Even natural predators, and many of them, wait for baby turtles to hatch. The survivors mature slowly—it can take up to 40 or 50 years before a sea turtle is ready to mate and reproduce. Between slow maturation and a high death rate, it is a very real possibility that these endangered creatures will become extinct. It is crucial for us to realize this and take action to help and protect them.
Turtles Face Many Threats
The most direct harm to the sea turtles is caused by poachers who kill adult turtles for their meat, fat, and shells, and dig up turtle eggs. Both meat and the eggs are considered delicacies and the shells are turned into souvenirs. Buying any part of a turtle is unethical and illegal. Turtles also get caught in the trawlers of fishermen. Pregnant females drown in commercial shrimp and fish nets when they swim through shallow waters to nest.
At key moments a sea turtle’s life cycle is sensitive to light and temperature, which have been changed by human activity in recent years. When baby turtles hatch, they head toward the brightest light, which used to draw them to the sea. With so much light from cities visible on the horizon, millions of young turtles head toward land instead of the water. When the sun rises, they die unprotected from the heat. This is photopollution, when manmade light sources disrupt natural patterns of light and darkness. Meanwhile, ever popular beachfront development continues to spread on and destroy fragile nesting sites and contribute light and noise pollution which scare off and confuse nesting females and new hatchlings.
Another disruption of the sea turtle’s life cycle is within the egg itself. The temperature of the sand around the egg affects how long the turtle needs to grow before hatching. Temperature also determines the sex of the baby. This is called temperature-dependent sex determination. Rising climate due to global warming is affecting this sensitive egg development, interrupting the proportions of males to females among sea turtles. These are just a few of the ways we are directly and indirectly harming sea turtles. It is important that we extend help to them now.
We Need Them Alive
Sea turtles serve important ecological functions and we need them to survive. These reptiles play vital roles in their food webs that affect humans. For example, some jellyfish eat the larvae of fishes that are wanted for human consumption. When leatherback turtles eat the jellyfish, more of the fish survive that people want eat. The olive ridley and the loggerhead have interactions with species that affect the survival of other animals and plants in the ocean, and the health of the ocean affects human well-being. Sea turtle diets, like those of the hawksbill and green turtle, are also part of the delicate balance with coral reefs and seagrass beds. Coral reef health affects huge regions of ocean and land, and seagrass health affects many other species of fish that are important to the fishing industry. If the sea turtles disappear, some of our own food sources will decline, too.
Many Hands Are Needed
The international community has recognized the need to protect sea turtles for several decades.
Global networks, like the IUCN*, work to find solutions to environmental problems such as protecting sea turtles across many countries’ boundaries. CITES** is an international agreement between governments; countries that work together in CITES try to regulate trade so that wild plants and animals are not endangered by international exchange. To actually do this requires impressive cooperation of many governments. Sea turtles are strictly restricted in international trade.
Costa Rica protects the beaches where sea turtles come to nest. All visitors are required to obey regulations for the turtles’ safety. This country does participate in CITES and does not allow killing sea turtles for food or any other reason. Other countries that allowed harvesting turtles and eggs no longer have any turtles gracing their shores. It is illegal for fishermen to ignore precautions that help protect sea turtles. In a few circumstances, such as those of the olive ridley, the government permits citizens to collect eggs during certain time periods.
Costa Rica’s government and the international community make an effort to defend these species of turtles. As strong as these international promises may be, funds, manpower, and resources still run short and sometimes laws are not fully enforced. It cannot be understated how essential it is for visitors to Costa Rica and other countries to understand the importance of these creatures and know how to help.
See Them, Help Them
People flock every year to witness turtles in any activity. As we enjoy the beauty of the loggerhead and the agility of the green turtle, we must help them in return. When you are in Costa Rica, or any country where sea turtles live or turtle products are sold, you can help in several ways.
Do not buy any food or souvenir that came from a turtle. As long as there is a market for souvenirs from shells or foods made with turtle eggs or meat, the fate of these delicate creatures is at greater risk. Refusing to purchase any items does make a difference.
When visiting turtle nesting beaches, it is important to strictly follow rules that help protect the turtles. Be quiet, do not make sudden movements, and do not use any lights or camera flashes.
When diving or snorkeling, trying to touch or feed a turtle is not safe for you or the sea turtle.
A Sensitive Existence
The populations of these turtles are shrinking so fast that any more harm is significant and long-lasting. Sea turtles naturally have a low survival rate from birth, and human pressures may prove fatal to these graceful mysteries. Preserving their beaches and respecting their space both on land and in water is vitally important for their survival.
*The IUCN is the International Union for Conservation of Nature.
**CITES is the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
World Wildlife Foundation: www.panda.org
Leenders, Twan. A Guide to Amphibians and Reptiles of Costa Rica. Zona Tropical, S.A, Miami, FL, 2001.