The Galapagos Islands' legendary giant tortoises are not the only ones facing extinction. Their cousins, the sea turtles, are also endangered, according to the International Union for Conservation of Nature (IUCN).
In the Galapagos, the Pacific green sea turtle (Chelonia mydas) is the most common. According to the IUCN, this species is critically endangered due to population decline. It is the only species of sea turtle that reproduces in the Galapagos.
Very common in the Galapagos Marine Sanctuary, they often have a darker, slightly domed shell. Their extremities are also darker than most Pacific green turtles. For this reason, they have sometimes been considered a separate species, sometimes called the black turtle (Chelonia agazsizii), but this view is now controversial. They are thought to be a subspecies (Chelonia mydas agassizii) of the Pacific green turtle.
The green turtle is also known as the soup turtle, a clear indication of its former use by humans. However, since 1988, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has prohibited trade in eggs, meat, and live or dead green sea turtles. Contrary to what you may think, the name green sea turtle does not refer to the brown to olive green color of its shell, but to the color of its body fat. In fact, adult green turtles are exclusively herbivorous, feeding on sea grass, algae or sea lettuce leaves, which they can tear off and chew with their serrated jaws. Only hatchlings are carnivorous, meaning they eat meat. Their diet includes crabs, shellfish and jellyfish.
When sea turtles reach sexual maturity, between 25 and 35 years of age, they return to their natal waters to reproduce. To do so, they travel long distances (over 2,600 km), guided by their internal compass, which uses the Earth's magnetic fields for orientation, and by their good eyesight, which allows them to orient themselves according to the position of the sun or the movement of the waves.
A few weeks after mating, the females return to the beaches where they hatched to lay their eggs. It is believed that the animals return to the beaches where they were born because they find good conditions for their offspring.
Many threats
The tiger shark is the main predator of adult green turtles. Hatchlings are preyed upon by a much larger number of species, including crabs, seabirds, large fish and marine mammals. In addition, cats that have returned to the wild also prey on eggs and hatchlings.
Another major threat to sea turtles is man. Increased boat traffic leads to horrific shell injuries, loss of limbs and often death. Fishing also threatens sea turtles, as they are often accidentally caught in fishing nets or become entangled with their limbs. As a result, they are unable to come to the surface to breathe and drown miserably.
The Galapagos Islands continue to be a popular tourist destination. In the last ten years alone, the number of visitors has increased by over 50%. This has led to a sharp increase in boat traffic to the islands for shopping, transportation, and diving and snorkeling excursions. All of this contributes to the dramatic increase in sea turtle injuries and deaths.
Tourist activities such as beachcombing, kayaking and snorkeling along the coast or from beaches where green turtles lay their eggs affect the animals. Noise and excessive beach activity alter sea turtle habitat and can cause behavioral disturbance or, in the worst case, migration.
Another major threat to sea turtles is man. Increased boat traffic leads to horrific shell injuries, loss of limbs, and often death. Fishing also threatens sea turtles as they are often accidentally caught in fishing nets or become entangled with their limbs. As a result, they are unable to come to the surface to breathe and drown miserably.
The Galapagos Islands continue to be a popular tourist destination. In the last ten years alone, the number of visitors has increased by over 50%. This has led to a sharp increase in boat traffic to the islands for shopping, transportation, and diving and snorkeling excursions. All of this contributes to the dramatic increase in sea turtle injuries and deaths.
Tourist activities such as beachcombing, kayaking and snorkeling along the coast or from beaches where green turtles lay their eggs affect the animals. Noise and excessive beach activity alter sea turtle habitat and can cause behavioral disturbance or, in the worst case, migration.
Another significant threat comes from microplastics trapped in the sand. These tiny particles give the sand a darker color, leading to faster heating and higher temperatures. This is fatal because the sex of young turtles is determined by the incubation temperature. The higher the temperature, the more females hatch. Females are certainly important, but if there are mostly female turtles, they can't reproduce in sufficient numbers to ensure the survival of the species.
Help from the sky
A team of researchers from the Charles Darwin Research Station, in collaboration with the Galapagos National Park Authority, is trying to find out if and how human presence affects sea turtles. For the past two years, a team of researchers has been using drones to monitor sea turtles in the famous tourist spot of Tortuga Bay. The use of drones ensures that the sea turtles are not disturbed. This allows the researchers to not only record the number of animals on the beach and in the water, their visual condition and activities, but also boat traffic and tourist activity at the site. Because the study began in the absence of tourists (due to the Covid-19 pandemic), we also have representative comparative data on animal behavior when there are few people in Tortuga Bay.
This year, tourist numbers have returned to pre-pandemic levels. This makes it especially important to continue the study this year. It will provide us with up-to-date, reliable data that we can use as a basis for making tourism in the Galapagos more sustainable and less dangerous for sea turtles, thus guaranteeing their habitat and survival.
Help us
Help us conserve the natural habitat of the green sea turtle. This is the only way to ensure the long-term survival of these fascinating animals for thousands of years to come.
Your donation will help ensure that the green sea turtles of the Galapagos bring a smile to the faces of many.