Even if you are not Aquaman or a fan of the underwater world or reptiles, you are probably familiar with sea turtles because you have come across some news or pictures featuring them. Unfortunately, it is often the stuff concerning their endangerment or entrapment in nets.
But these cute animals have a lot of interesting and positive things to offer.
We will share one with you right away: even though it has the word sea in the name, this type of turtle does not have gills which would allow it to take oxygen in and release carbon dioxide out. So, how does a sea turtle breathe? How long can a sea turtle hold its breath?
These are exactly the questions we will answer in this article. And many more! Join us in exploring the (shallow) depths of seas and oceans where sea turtles usually reside (and breathe)!
How Did Sea Turtles Adapt To Life In Water?
Before we tell you how long sea turtles can hold their breath, it is important to explain how they adapted to life in water since it was not their original habitat.
Sea turtles are cold-blooded organisms, meaning their body temperature depends on the temperature of the external environment, which is why they live mainly in tropical and subtropical seas. Thanks to its body size, only the leatherback turtle inhabits colder seas at higher latitudes.
Sea turtles also regulate their body temperature by controlling blood flow through their skin and fins.
2. Underwater Movement
Temperature is not the only factor essential to surviving in a new environment. Since sea turtles spend almost their entire life in the sea, they have developed and evolved a series of other adaptations that make it easier for them to move and stay in the water.
The main adaptations are hydrodynamic armor and limbs transformed into fins. The front fins of sea turtles are used for swimming, while the rear ones have the function of a rudder and are used to direct the body, as well as to dig and cover the nests where the females lay their eggs.
3. Underwater Breathing
When it comes to breathing underwater, these turtles transport oxygen through the body very efficiently and tolerate low oxygen concentration in the tissue, which allows them to stay underwater for long periods of time.
Sea turtles are also able to maintain the appropriate balance of water and salt concentration in their body fluids underwater (especially during their migrations), which is still a subject of great interest to scientists.
How Long Can A Sea Turtle Hold Its Breath?
Although they spend almost their entire lives in the sea, sea turtles are air-breathing animals with lungs, which is why they occasionally come to the surface to take in the air.
It means that they have alternating periods of intensive ventilation, i.e., breathing, which happens when the turtles come to the surface, and a period of holding their breath when underwater.
Before diving, they breathe 2 to 3 times and inhale a sufficient amount of oxygen in their large lungs. How long a turtle can go without going back to the surface depends on its activity level.
During foraging for food or long migrations from foraging grounds to sand nesting beaches or vice versa, which are activities that require high consumption of energy and, therefore, oxygen, marine turtles will surface every 4 to 5 minutes.
During their “normal” swimming and activities that are not so taxing, they can go from 45 minutes to 1 hour without resurfacing, while resting or sleeping allow them to spend up to 7 hours straight underwater.
Interestingly, up to 9 minutes can pass between heartbeats when they are at rest. The reason for this is that their already slow metabolism slows down even more, which lowers the heart rate and thus enables rest without consuming much oxygen.
Fun Facts About Sea Turtles
Sea turtles are reptiles that appeared approximately 250 million years ago. They are considered to have started roaming the Earth with dinosaurs and the first primitive mammals in the Triassic geological period (205-250 million years).
These creatures began to inhabit the seas and oceans during the last 150 million years and have hardly changed since then.
Sea turtles belong to the Testudines order, along with terrestrial and freshwater turtles. There are seven species of sea turtles in the world that taxonomically belong to the Chelonioidea superfamily.
- Cheloniidae Family
The flatback sea turtle (Natator depressus), green sea turtle (Chelonia mydas), hawksbill sea turtle (Eretmochelys imbricata), Kemp’s ridley sea turtle (Lepidochelys kempii), loggerhead sea turtle (Caretta caretta) and the olive ridley sea turtle (Lepidochelys olivacea) belong to the Cheloniidae family.
The main characteristic of this family is the hard keratinized shell, which consists of ossified plates.
Sea turtles in this family are small(er), with the shell length ranging from 2 to 5 feet cm and the body weight in the range from 200 to 330 pounds. Rare specimens of the green sea turtle can weigh almost 900 pounds.
- Dermochelyidae Family
The leatherback sea turtle (Dermochelys coriacea) is the only member of the Dermochelyidae family and is characterized by a soft leathery shell without ossified plates.
The leatherback turtle is not only the largest sea turtle species but also the heaviest non-crocodile reptile. It can grow between 6 and 9 feet in length, 3 and 5 feet in width, and weigh over 1,500 pounds.
2. Life Expectancy
Sea turtles live an average of 60 to 70 years. They grow slowly and, depending on the species, become sexually mature and reach adulthood around the age of 20.
3. Body Shape Advantages And Disadvantages
Compared to their land or freshwater cousins, sea turtles have a more spindle-like body shape, which has both good and bad sides.
The bad sides are the reduced mass and inability to retract the head and limbs into the shell, which is something other turtles species can do, especially when facing predators.
The positive side of having a fusiform body shape is the reduced friction and drag in the water, which allows sea turtles to move through the water more easily and quickly.
4. Migrations And Movement
Due to their metabolic adaptations and physiological mechanisms that we described previously, marine turtles not only have the ability to stay underwater for a long time but also make long journeys. It is quite important for them since they are migratory species of reptiles.
The leatherback turtle is actually one of the most migratory animals in the world, traveling more than 10,000 miles every year. One female specimen was even observed to have traveled 12,000 miles. Loggerhead turtles travel up to 8,000 miles per year.
These seemingly tireless animals can work for a long amount of time during their migratory adventures, sometimes swimming non-stop between 24 and 36 hours.
Although they are slow swimmers that move at speeds between 1.7 m/h and 6.2 m/h, they are known to get a speeding ticket or two occasionally. The leatherback turtle, for example, can swim at a speed of up to 22 m/h.
The leatherback turtle is also the type of sea turtle that can dive the deepest, reaching over 3300 feet.
Since they have oil in the skin and their leather shell can absorb nitrogen, leatherback turtles do not encounter decompression issues which is a common occurrence at these depths, allowing them to roam in deep water freely.
Other species can go over 600 feet.
Even though they have the deep diving ability, most species of sea turtles spend their time swimming and feeding at depths of 30 to 150 feet.
Although most species of sea turtles migrate, some are known to go into a state similar to hibernation or winter sleep. At that time, they rest on the muddy seabed and, in rare instances, come to the surface to breathe air.
Of course, they are able to do this thanks to their ability to spend long periods underwater.
Unfortunately, when they are in a state of hibernation, these turtles often get trapped in nets.
But what is even worse is that people return them immediately to the water, which should not be done because they are in an inactive state that can lead to drowning. They should first be allowed to regain consciousness with proper handling and only then let go back to the sea.
Sea turtles are among the most interesting animals in the world because even though they spend almost their entire lives in water, they have lungs instead of gills. Because of this, they have to go up and surface on a regular basis to breathe air in.
When dealing with serious matters like searching for food, this happens every 4 to 5 minutes. The more mundane activities allow them to go up to 1 hour without breathing in oxygen.
Resting requires the least amount of oxygen, enabling them to spend up to 7 hours surrounded just by H2O (and also some chlorine, sodium, and other elements).
If you want to find out even more exciting info about marine turtles or need clarification regarding some of the stuff in the article, use the comments section!