Why Are Sea Turtles Endangered & What Can We Do About It?
Nearly every species of sea turtles are endangered, with three sea turtle species classified as critically endangered. So, why are sea turtles endangered?
The cause of their endangered status ranges from pollution, climate issues, and habitat destruction to fishing, poaching, and slaughter for their meat, eggs, and shells. But while this may seem daunting, there are many amazing conservation efforts that we can all support and even be a part of to help sea turtles survive and thrive.
As we raise awareness about why sea turtles are endangered, it’s important to understand more about their physical characteristics, habitat, and behaviors.
What are the Different Types of Sea Turtles?
There are seven recognized species of sea turtles in the world. All of these species of sea turtles are endangered. These are:
- Loggerhead sea turtle (Caretta caretta): Hard-shelled. On average, weigh 230 pounds and measure 3 feet from beak to tail.
- Green sea turtle (Chelonia mydas): Hard-shelled. On average weigh 300 pounds and measure 3 to 4 feet from beak to tail.
- Leatherback sea turtle (Dermochelys coriacea): Soft-shelled. It can weigh up to 2,000 pounds and measure 6.5 feet from beak to tail.
- Hawksbill sea turtle (Eretmochelys imbricata): Hard-shelled. On average, weigh 100-150 pounds and measure 2-3 feet from beak to tail.
- Kemp’s ridley sea turtle (Lepidochelys kempii): Hard-shelled. Typically weigh less than 100 pounds and measure 2 feet from beak to tail.
- Olive ridley sea turtle (Lepidochelys olivacea): Hard-shelled. Weighing 80-110 pounds and measuring up to 2.5 feet.
- Flatback sea turtle (Natador depressa): Hard-shelled. Weighing up to 190 pounds and measuring between 3 to 3.5 feet.
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10 Fun Facts About Sea Turtles
- Many sponges are toxic for other species to eat due to their glass-like spikes that grow within them. However, Hawksbill Sea turtles are completely immune to these spikes, so they are considered a great help around coral reefs as less sponges allow for a greater diversity of species to thrive.
- While land turtles and tortoises can retract into their shells, sea turtles are unable to do so.
- Sea turtles don’t have ear holes! While they do still have ears, they are covered by a thin layer of skin called the tympanum.
- The eyesight of sea turtles is quite good. Typically, they are far-sighted in the water and more near-sighted above water. They can perceive shorter wavelengths of the electromagnetic spectrum, allowing sea turtles to see UV light. Something humans can’t perceive without technology!
- While typically sea turtles prefer to leisurely cruise at around 1-5mph, when frightened, they have been found to swim up to 23mph.
- Most sea turtles build their nests at night, but the Kemp’s ridley sea turtle consistently likes to build their nests at night.
- The females of both ridley sea turtles like to nest in large groups called “arribadas”, which is Spanish for “arrival”. No other species of sea turtles have been found to show this group nesting behavior.
- The beaks of sea turtles is made of keratin, which is the same thing our fingernails and rhinoceroses’ horns are made of.
- Although leatherbacks are considered cold-blooded, they have internal mechanisms that allow them to regulate their body temperature, allowing them to survive even in the colder waters of the Arctic circle and the warmer temperatures of tropical beaches.
- Kemp’s ridley sea turtle are considered the smallest of the seven species, with leatherbacks being the largest.
Where do Sea Turtles Live?
Sea turtles are found in nearly every ocean worldwide, save for deep within the Arctic and parts of the Southern Ocean closest to Antarctica. However, some species have been found to migrate through the Arctic circle.
Overall, sea turtles have an extensive range of habitats and places to call home. The oldest and largest of sea turtles, the leatherback, also have the most extensive range of nesting and feeding grounds that can have up to a 10,000-mile span between them (For reference, the distance from New York City directly to the South Pole is 9,031.68-miles, that’s no sweat for a leatherback!)
Leatherback sea turtles have the broadest range of all species found from as far north as the Arctic Circle to as far south as the tip of New Zealand.
Followed by leatherbacks are loggerhead sea turtles, which are abundant throughout the world, especially in North America and the Mediterranean Sea.
At the very end of the range spectrum are the flatback sea turtles, whose range is restricted to the tropical waters of the Pacific Ocean around Australia and Indonesia.
Behavior and Diet of Sea Turtles
The study of sea turtle behavior has been hard due to the solitary habits of sea turtles in the open ocean; as fast swimmers and adept divers, it can be hard to track sea turtles once they have left the shore. Most sea turtles can dive up to 1,000ft below sea level, but leatherbacks can quickly dive up to 3,000- even 4,000ft! Even the most well-trained scuba diver can swim down to 60ft but must be extremely careful when returning to the surface.
Female sea turtles are the only members to return to land once hatched. Males opt to stay in the water unless they must return to land.
Sea turtles have an average lifespan of 50 years but can live well beyond that. Some sea turtles reach reproductive maturity as young as seven years old, while others are not mature until they are well in their 30s. Once they have reached maturity, the mating season for sea turtles can range from early spring to early fall.
Where Do Sea Turtles Lay Eggs?
When females are ready to lay their eggs, they often return to the same beach where they hatched. Once on shore, they will scout out the best possible location, often creating many “false nests” until she finally finds the ideal spot. There, she will begin to dig with her flippers; once deep enough, she will twist her body to create a larger space until finally, she has created an adequate nest.
Depending on the species, she will spend the next several hours laying her eggs, which can be as many as 50-200 eggs within a clutch. After laying her eggs, she will cover them in the sand and return to the ocean.
It is important that the beaches where they make their nests remain free from bright lights at night. Sea turtles have excellent vision and use light and color to hunt, stay aware and hidden from predators, and to navigate.
Eggs typically take two months to incubate and hatch. The temperature of the sand surrounding the eggs will influence both the speed of incubation and the sex of the hatchling. The hotter the environment, the faster the hatchling will mature, and the more likely it will be female. The cooler the environment, the slower the growth, and the more likely it will be male. This is called temperature-dependent sex determination, which is quite different from the chromosomal basis in humans.
Once the eggs have matured, the hatchlings will erupt from the sand, typically between the middle of the night and early in the morning. This begins the sea turtle’s journey all over again. This trek from the warm nest to the roaring ocean waves can be quite dangerous for hatchlings as poachers, seagulls, and other predators can easily pick away at the hatchlings. That is why many conservationists have begun programs to find nests, monitor them, and provide protection on the day of hatching.
What Do Sea Turtles Eat?
The diets of sea turtles are incredibly diverse. Some species, such as green sea turtles opt for an herbivorous diet, surviving off seaweed, algae, and other marine plants. Many species are omnivorous and will consume any number of marine plants and use their hard beaks to crack the hard outer shells of crabs, whelks, and oysters and eat fish, shrimp, and even coral.
Loggerheads are the only known carnivores, however, their hatchlings are omnivorous.
Two outliers are the leatherbacks who are considered gelatinivores, meaning they subsist mostly from gelatin-like prey such as jellyfish and sea squirts.
The other are the hawksbill turtles, which are considered spongivores because they consist mostly of sponges for their diet.
What Can Be Done to Help Sea Turtles that are Endangered?
As is with most endangered creatures, the reasoning behind the sea turtles’ endangered staus multifaceted and complicated. Many of the reasons can be linked directly to human activity, from entanglement in the nets of fisheries, boat strikes, pollution from the excess of plastics in the oceans, poaching, and the destruction of their natural nesting habitats by land development severe weather patterns caused by climate change.
Another reason why sea turtles are endangered is that they can get caught up in trawl nets that are used to catch shrimp and other small marine animals. The turtles get caught in the nets and can be without air for 30 minutes or more, which endangers their lives. Turtle excluders are devices that have been developed to help prevent sea turtles from getting entangled in the nets.
While some people aim to harm sea turtles for monetary gain, there are many wonderful groups of people working in science and conservation who work tirelessly to protect sea turtles that are endangered and injured.
Sadly, many of these efforts are understaffed and underfunded and are always in need of volunteers and supporters throughout the world.
Many institutions aim towards helping sea turtles focus on the rehabilitation of injured turtles found throughout the world and developing breeding programs to protect the known nesting beaches of females. To study and understand sea turtle migration and behaviors better, scientists will often safely capture turtles, secure a transmitter device to their shell, and then use satellite technology to track the turtle on its journey throughout the world.
Below is a brief look inside a sea turtle rescue center.
Oceanspirits.org based in Grenada
Other Resources to Use with a Sea Turtle Study:
Download the Sea Turtle Activities Printable Pack
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