The Sea Turtles (superfamily Chelonoidea) have been around for about 100,000 years. These curious animals are large reptiles that have adapted to life in s alt water. Since then, they have become a fundamental part of their habitats.
Currently, all sea turtles are considered threatened by human activity. Therefore, it is very important to raise awareness about the importance of its conservation, both for marine ecosystems and for us. Do you want to know everything about them? Don't miss this article on our site, in collaboration with the CRAM Foundation, about the characteristics of sea turtles, where they live and much more.
Classification of sea turtles
Turtles are tetrapod vertebrates of the class Reptilia, such as snakes, lizards or birds. Within the reptiles, turtles form the order Testudines which is characterized, above all, by a bony shell that protects its internal organs.
More than 100,000 years ago, some land turtles adapted to living in the sea. They were the ancestors of the superfamily Chelonioidea: today's sea turtles. Today, there are only 7 species of sea turtles that belong to 2 families: the quelonidae and the dermochelidae.
The chelonids (Cheloniidae) have a shell made up of bony plates. In this group we find 6 species:
- Loggerhead sea turtle (Caretta caretta)
- Green Turtle (Chelonia mydas)
- hawksbill sea turtle (Eretmochelys imbricata)
- Kemp's ridley sea turtle (Lepidochelys kempii)
- Olive Turtle (Lepidochelys olivacea)
- Flatback Turtle (Natator depressus)
For their part, the dermochelids (Dermochelyidae) have a shell made up of hard skin. It only has one representative:
Leatherback sea turtle (Dermochelys coriacea)
Characteristics of sea turtles
The ancestors of sea turtles adapted to living in the oceans, and their characteristics changed as a result. Their shell is smoother and flatter than that of land turtles, making it easier for them to pass through the water. Their legs changed into flippers, allowing them to swim great distances. They use the front ones to propel me, while the rear ones set the course.
In addition, these turtles have a more efficient metabolism than land turtles, as well as a greater number of red blood cells, that is, they have a greater capacity to retain oxygen. They also have adaptations to s alt water: they have a s alt gland in their eyes, whose function is to expel excess s alt from their body.
As for its behaviour, it depends on each species and even on each population. They are generally solitary animals that come together only during the breeding season. To do this, some turtles travel thousands of kilometers, that is, they are animals migrators
Where do sea turtles live?
Now that we know the characteristics of sea turtles, where do they live? Sea turtles can be found in oceans and seas around the world, except Antarctica and the Arctic. However, each species has its distribution. Some of them are only found in very specific areas, such as the Australian flatback turtle or certain populations of Mediterranean loggerhead turtles.
As for the habitat of sea turtles, it depends on the phase of their life cycle. Newly hatched turtles usually live offshore, swimming adrift alongside aggregations of plankton, where they feed and camouflage. When they are juvenile, they move to shallower areas, such as coral reefs, some places with great abundance of resources.
Finally, when they reach reproductive maturity, sea turtles are already adults and begin to migrate from feeding areas to feeding areas. of reproduction and vice versa, so they spend much of the year traveling in the open sea
Migration of sea turtles
All species of sea turtles are considered migrants, since, at least in one phase of their life, all carry out movements The hatchlings move to the open ocean, juveniles return to shallower areas and, when sexually mature, migrate to mating grounds each year during the breeding season.
In mating areas, females and males copulate. Later, the males return to the feeding areas, that is, they usually never leave the sea. The females, meanwhile, go to the beaches to build the nest and lay eggs. Normally, they do it on the same beaches where they were born. Afterwards, they return to areas rich in food.
Discover how sea turtles reproduce in this other article.
How do sea turtles live?
Sea turtles are very long-lived animals. Some species can reach 90 years of age During this time, they are usually solitary animals, although they sometimes aggregate to feed and reproduce. Some females all nest at the same time, which can help them protect the eggs.
They are, therefore, oviparous animals. They dig nests in the sand on beaches and it is the warm sand that is responsible for incubation. They can lay more than 150 eggs per nest and usually nest several times during the same season. However, only 1 in 1000 hatchlings make it to adulthood.
As for what they eat, sea turtles are usually carnivorous or omnivorous Some, such as the leatherback sea turtle, the Kemp's ridley sea turtle or the flat tortoise, they feed mainly on other animals, especially invertebrates. Other turtles also eat a lot of algae and sea plants. This is the case of the loggerhead sea turtle, the olive ridley sea turtle and the hawksbill sea turtle.
Without a doubt, a very curious diet is that of the green turtle. As we told you in the article on What do sea turtles eat, the green turtle consumes other animals when it is small, but when it reaches adulthood, it feeds almost exclusively from algae and plants. Therefore, it is considered the only herbivorous sea turtle
Main threats to sea turtles
Six of the seven species of sea turtles are Globally threatened Loggerhead, leatherback and olive ridleys are vulnerable, The green turtle is endangered and the Kemp's ridley and Hawksbill are considered critically endangered. As for the flatback turtle, there is insufficient data on the status of its populations.[1]
Therefore, sea turtles are finding it increasingly difficult to survive in the marine environment. Why? These are the main threats to sea turtles:
- Fishing gear: Turtles get caught in nets and other fishing tools by accident, causing wounds and injuries. Also, when the nets rise to the surface and drag the turtles, they can cause decompression sickness due to the rapid change in pressure.
- Waste contamination: turtles confuse waste, especially plastic, with their food. They cause drowning, obstructions and, as a consequence, malnutrition. In addition, they can become entangled in the fins, even causing amputations.
- Chemical pollution: discharges of contaminated water, oiled areas, nuclear waste, etc. they pollute the water they inhabit.
- Noise pollution: noise from submarines, shipping, oil infrastructure, etc. they generate discomfort and stress, and can interfere with the normal behavior of the turtles.
- Habitat destruction: Trawling also destroys its natural habitat, such as the most productive benthic areas. In addition, their nesting sites are becoming smaller due to the "cleaning" and overcrowding of the beaches, as well as uncontrolled coastal urbanization.
- Ship Strikes: In recent decades, there has been an increase in shipping, increasing the number of ship strikes.
- Climate change: due to the increase in global temperature, changes are taking place in the nesting place, as well as in the number of females and males emerging from the eggs. In addition, climate change is seriously affecting their feeding grounds, such as the coral reefs.
- Illegal fishing: Turtle meat, shells and eggs are highly valued in some parts of the world.
How to help sea turtles?
The ecological role of sea turtles is fundamental, both for their ecosystems and for human beings. For example, they are essential to avoid overpopulations of jellyfish, which they usually feed on. But is it possible to help them?
We can help sea turtles by making small changes to our daily routine, like:
- Reduce the use of plastics and single-use objects.
- Reuse and recycle our waste.
- Buy local products with labels of sustainable fishing.
- Reduce our energy expenditure.
- Use public transport.
- Reduce meat consumption (mainly responsible for deforestation and a large part of CO2 emissions).
- Environmental education in our society and become aware at the individual level of what is happening.
Also, if you want to help sea turtles, you can lend us a hand at Fundación CRAM We are dedicated to the conservation of the marine environment through local actions, such as the recovery and reintroduction of sea turtles and other animals. You can help the oceans by sharing our work, volunteering, sponsoring one of our turtles or through donations. Donations can be fixed amounts as low as €1 per month, or one-off donations. Help us protect sea turtles.
