The story of sea turtles is an old one. The first record of their existence dates to the beginning of the Mesozoic Era, a period that began 225 million years ago and ended 65 million years ago, during which life flourished on our planet and on land. It was in this era when the dinosaurs appeared, thrived and went extinct.
Sea turtles, like dinosaurs, belong to the reptiles, and have a prodigious life history. They shared the lands and the oceans with the fish, birds, flowers, and conifers that developed during the above-mentioned era. But when it ended, they managed to survive one of the largest extinctions on our planet. They witnessed the extinction of many species with which they had co-existed for millennia, and were present at the birth of mammals and, of course, of human beings.
Thus, with a surprising tenacity, these millennial and long-living creatures (true living fossils) have accompanied the planet's evolution for millions of years. They have survived until our days with practically the same anatomical characteristics with which they first appeared on the face of the Earth.
The country of Sea Turtles
Mexico is considered by many as the country of sea turtles. The diversity of coastal environments and the wealth of our coasts offer ideal conditions for their nutrition, rest and reproduction. Of the eight species that exist in the world today, we have the privilege of having seven of them reproducing on our coasts, both on the Pacific side as well as the Atlantic, from the Gulf of Mexico to the Caribbean Sea.
These species are:
- The Green turtle (Chelonia mydas)
- The Loggerhead (Caretta caretta)
- The Hawksbill (Eretmochelys imbricata)
- The Leatherback (Dermochelys coriacea)
- The Black turtle (Chelonia agassizi)
- The Olive Ridley (Lepidochelys olivacea), and
- The Kemp's Ridley (Lepidochelys kempii).
The only one that does not nest on Mexican beaches is the Australian Kikila (Chelonia depressa).
If Mexico is the country of the sea turtles, we could say that Quintana Roo is the Mexican state of the sea turtles: four of the seven species born in Mexico come to nest on its coasts, particularly the Green and the Loggerhead.
Great Land-born Navigators
They are excellent navigators, sea turtles spend most of their life in the ocean. They migrate during different stages of their development, both to their feeding and resting places, and to their nesting sites.
Female and male sea turtles are known for their long migrations, during the breeding season, of hundreds or thousands of miles to the coasts where the nesting beaches are, and where they tend to remain close to shore, for various months while they mate.
However, and paradoxically, sea turtles begin their lives on land, which makes them particularly vulnerable. Year after year, from April until September on the Atlantic coasts. and from June until March of the following year on the Pacific coasts, the female turtles have to go out on dry land to nest.
It is believed that each mother turtle returns to lay her eggs on the same beach where, at least a decade before, it was born. The males, on the contrary, never set foot on land again.
In most species the female turtles leave the ocean protected by the night's darkness, to search for a place on the beach to lay their eggs. With their powerful fins, they dig a hole in the sand, making a nest into which they will expel, one by one, their eggs.
In the case of the Loggerhead, they lay 100 to 120 eggs. The Green turtles lay from 130 to 150 eggs. Once the eggs are deposited. the turtles cover their nests with sand, erasing their trace, and return to the sea. They will only come back to the beach to nest again, which can happen many times during one season.
After 45 to 60 days, depending on the species, the baby turtles begin their difficult struggle for life. Still in the nest, one by one they emerge from their shell. Then, as though alerted by a biological clock, they all spring from their burial and hurry toward the sea, reinitiating the millennial cycle.
Though they have survived the first phase of their life, in which their nests are always threatened by predatory animals, by natural phenomena, or by man himself, they now face new threats. During their short walk toward the ocean, they can be devoured by birds, crabs, raccoons, dogs or any other predator.
More threats await them once they are in the sea. Of one thousand baby turtles, probabilities state that only one will reach adulthood.
When they leave the beaches, the turtles begin a phase of their life in the open sea that may last many, many years. During the first phases, the most vulnerable, they are frequently found in "floating beds" made up of seaweed. They can also be found in the tide lines formed by the front of the main currents, or else in the passive drifts of the ocean currents.
While they reach their reproductive age, which is after they are ten years old, they will go through a great variety of marine habitats. But they will always return to their starting point, to the coasts where they were born, to lay their eggs.
The human hand
Until the XIX century, the sea turtle population was very abundant and they were counted by the millions. This wealth made humans think that these beings were an inexhaustible resource. So, they were consumed indiscriminately, their eggs, their flesh or for their shell.
Although they are ancestral inhabitants of the seas, today it is evident that their relationship with man has put their ancient capacity for survival at risk. In the last century their numbers have dwindled drastically throughout the world, to the point where some species are now considered endangered or threatened, thus reducing the ability of their populations to overcome other changes humankind has also affected their environment with.
Yes, unfortunately the survival of the sea turtles is intimately related to human activities. The turtle's life cycle is complex and the same reasons that at some point in their evolution guaranteed their survival, has now turned them into extremely vulnerable organisms. Man's impact on their environment directly affects a good part of their vital cycle, and thus their viability as a species.
On top of the loss of nests on the beaches (due to depredation and plundering by animals and mostly humans), nesting beaches are reduced due to development, degradation of their feeding areas and the high mortality rate of both young and adult turtles due to illegal killing of these animals out at sea, or of the nesting females on the beaches, as well as of incidental fishing and the increased level of ocean pollution.
That is why for decades efforts have been made in Mexico, and throughout the world, to protect these creatures and their evolutionary heritage. It is here where the history of sea turtle conservation begins.
Efforts Geared Toward Saving Sea Turtles
In Mexico, the federal government established many measures geared toward protection, conservation, recuperation, and research of sea turtle populations. These efforts have worked to counteract both the deterioration of the environment in which sea turtles live and the direct threats to their survival.
The first big step was taken on May 1990, when the decree that permanently closed the fishing season for all sea turtles species in national waters published in the Diario Oficial de la Federación.
Three years later, in 1993, the Norma Oficial Mexicana de Emergencia (Emergency Official Mexican Regulation) 002-PESC-1993 established the obligatory use of sea turtle exclusion devices in dragging fish nets, in order to reduce their incidental fishing.
Also in 1993, the Mexican Inter-Secretarial Commission for Sea Turtle Protection and Conservation was established, followed in 1994 by the National Committee for Sea Turtle Protection and Conservation. That same year, all sea turtle species were listed in the Norma Oficial Mexicana (Mexican Official Regulation) NOM-059-ECOL-1994, which establishes the species and subspecies of wild flora and fauna which are endangered or threatened.
One of the most important strategies followed by the Mexican government for sea turtle population improvement has been though the creation of Sea Turtle Protection Camps on the country's most important nesting beaches. Today, the federal government operates 28 Sea Turtle Protection and Conservation Centers (CPCTM). Eight are in the Gulf of Mexico, two are in the Caribbean, and 18 are on the Pacific coast. To these we can add over 170 Sea Turtle Protection Centers operated by non-governmental organizations.
A successful protection program
A sea turtle protection experience that can well be described as successful is one that is carried out on the beaches of Quintana Roo's central coast.
Quintana Roo's coast, or the Mexican Caribbean, is the most important Atlantic coastal region for the reproduction of the Green and Loggerhead turtles, and it is precisely here where one of the greatest efforts to help improve the population of these today-threatened species is carried out.
One of the main non-governmental organizations working today to protect the nesting sea turtles is Flora, Fauna y Cultura de México, A.C. (Mexican Flora, Fauna and Culture). This is an organization that gives continuity to a protection effort that began more than 20 years ago in the Quintana Roo Research Center (Centro de Investigaciones de Quintana Roo, or CIQRO).
In 1995, when the latter disappeared, Xcaret Park took over this task as the "Sea Turtle Protection and Conservation Program of the Central Coast of Quintana Roo". It operated this effort on its own until 2002, when it turned the program over to Flora, Fauna y Cultura de México, A.C.
The "Sea Turtle Protection and Conservation Program of the Central Coast of Quintana Roo", which Flora, Fauna y Cultura de México operates, covers the area that includes some of the most important nesting grounds in the state of Quintana Roo: 12 beaches that spread through a 75-mile extension, stretching from Punta Venado, in the north, to Cahpechén in the Sian Ka'an Biosphere Reserve, in the south.
The protection effort is so large that in the last ten years (which includes the work carried out both by Xcaret Park and by Flora, Fauna y Cultura de México) more than 20 thousand nests have been protected, and approximately 2 million baby turtles of the above mentioned species have been let out to sea. That is why it is considered one of the most important programs on a national level.
Conservation: A Commitment to Our Future
It has often been said that humans are the only species capable of modifying the environment they live in. And, unfortunately, we constantly find evidence that these changes have damaged what we consider our natural heritage. It has taken us a long time to understand that this damage not only affects our environment, but also puts ourselves at risk.
However, we are also the only species that can work to preserve other species. It is here where we can possibly make a meaningful difference. We should acknowledge our duty as a species to preserve our heritage. This is a heritage that we should be able to keep and live with, the same way our children and the future generations should do too.
Sea turtles have managed to survive for millennia, becoming the most persistent witnesses of our planet's evolution. Today, threatened by man, they require our help to survive, so they can continue to swim the oceans of our planet. Yes, sea turtles are symbols of the past... but in their survival lies our hope for a better future.
By: Rodolfo Raigoza - Originally published on Vive México.