Graciela Tiburcio (Veracruz, 49 years old) knows everything about the sea turtles that navigate near the coasts of Mexico. The biologist —based in Baja California Sur, one of the main places for environmental protection and sustainability in the country— has spent years observing and learning from one of the longest-lived and oldest animals on earth. Turtles have survived for more than 200 million years on the planet. “And in less than a decade in Mexico we were about to make them disappear,” says the specialist, who in 2015 won the Ecological Merit award from the Mexican government.
In Mexico, there are seven of the eight species of turtles that exist in the world. In the 1970s, after devastating crocodile populations, the coastal population began to trade loggerhead turtle skin —now included in the Semarnat Official Standard as an endangered species. At that time, half of all the leather of this reptile that was sold in the world was of Mexican origin: “a quarter of the total international trade came from Baja California Sur,” the biologist details.
After establishing a ban on the species by the authorities and, with the encouragement of conservation programs, this turtle, like many others that reach the Mexican coasts, has managed to recover. “But, although we have managed to rescue the populations, the turtles are still at risk,” explains Tiburcio. The possible extinction of these reptiles is a shadow that has not ceased to haunt them and the various dangers that threaten them are still latent.
The vast majority of coastal areas in Mexico lack integrated policies to protect ecosystems. But the region where Tiburcio arrived more than two decades ago stands out for having the largest number of protected natural areas in the country, which occupy up to 42% of the region’s surface. “In Mexico we are lucky that seven of the eight species of turtles that exist come to our beaches. We live in a country rich in biodiversity”, he affirms. “They only spend 1% of their life cycle on land, when they are born and spawn. Imagine how little we know about them, ”he adds.
The threats that hang over turtles
As an article on global patterns of illegal exploitation of sea turtles recently published in the journal Global Change Biology highlights, the irresponsible use of wildlife for food, medicine, fads, aphrodisiacs, and spiritual fetishes represents a conservation challenge in the 21st century. . According to the work, it is estimated that more than 1.1 million sea turtles were exploited between 1990 and 2020 for some of the above purposes.
However, as the biologist denounces, “the main cause of death of these animals is “incidental and abusive fishing, against which the authorities do nothing”. Each year more than 325,000 turtles are killed by fishing. “They get stuck in the nets and from the effort they make to try to get free they end up drowning,” laments Tiburcio. On the beaches of Puerto Arista, in the State of Chiapas, in the last two months hundreds of them lost their lives entangled in the fishermen’s nylon meshes.
Ocean pollution, the garbage displaced by ocean currents and plastic microparticles, also wreaks havoc on their survival. “The turtles confuse the bags with jellyfish and swallow them,” says Tiburcio, witness to the lethal effect that ingesting waste had on these animals during his doctorate in Brazil. “It was shocking to see the plastic that came out of the bellies when doing the necropsies. The cause of death was always due to intestinal obstruction”, laments the expert.
The recent toxic tide of macroalgae, the sargassum that is invading the Caribbean beaches, also has devastating effects on them, still not as much as the unleashed urban and tourist development of the coasts. “Luckily, in Baja California Sur, businessmen are much more aware than in other places and try to integrate policies to protect them. Even so, the bad practices continue”, explains Tiburcio.
When they hatch from the shell, the hatchlings head towards the sea guided by the light reflected by the stars and the moon, acting together with the Earth’s magnetic field, stellar compasses for many species. “The more powerful artificial lighting makes them disoriented and diverted,” says Tiburcio. “Through living together for so long they have taught me a lot, how to read time,” he says.
When many turtles come out at the same time to lay their eggs in a short period of time, they are predicting that a storm is coming, that there will be rain and storm surge. “It is as if the turtles know that the beaches are going to be destroyed and they will not be able to nest and secure their eggs. They anticipate the meteorological phenomena ”, announces the amazed biologist, witness of a prodigy of nature with hints of a miracle when she recounts it. “It is that, if we were more aware that the beauty of this planet is not infinite, we would take better care of it. That is why I believe that environmental education is one of the areas in which more should be invested ”, she affirms.
Advances in technology, with the development of increasingly sophisticated techniques, have made it possible to monitor in greater detail the journey of these reptiles throughout ocean basins and on the high seas. “We can no longer only track the starting point and arrival point, the new satellites incorporate transmitters that provide us with, among other data, salinity, the heart rate of the specimens or the depth they reach,” he explains.
In addition to involving various sectors of the region in turtle conservation programs, Tiburcio has another challenge: to recover their cultural value. “The turtles have played a very special role in this territory, they have a very special bond with the native peoples,” he points out. Some of the rock paintings made with mineral pigments found in the caves of the northern peninsula of Mexico outline these reptiles as a representation of the interaction of man with nature. “It is about an ancient link with the South Californian towns that is being lost”, says Tiburcio, recognized last September by the L’Oréal award as one of the 60 ‘Women who move Mexico’.
It is estimated that only one in 1,000 sea turtle hatchlings manages to reach adulthood. The lucky one who manages to reach the ocean and navigate it, avoid each of its dangers, will one day return to the beach where she was born to continue the lineage. “Her luck depends on our actions,” concludes the biologist.
