Educational Series: Sea Turtles, Ancient Survivors of the Oceans, Could Soon be Extinct

By Nick Engelfried
With evolutionary origins stretching back to the age of the dinosaurs, sea turtles are one of the oldest groups of large animals alive today. They range throughout the world’s oceans, venturing onto land only to lay their eggs, and are among the most beautiful and majestic of marine creatures. However, as a group, they are also among the most endangered. To ensure sea turtles’ long evolutionary journey is not cut short by human greed and carelessness, it is essential that we understand them and the important role they play in their ecosystems.

The earliest known members of the sea turtle family are thought to have evolved about 120 million years ago, well into the time of the dinosaurs. Long before famous dinosaur species like Tyrannosaurus rex had appeared, sea turtles were plying the waters of prehistoric oceans much as they do today. Ancient sea turtles were among the very few groups of large vertebrates to survive the mass extinction that wiped out dinosaurs and so many other creatures at the end of the Cretaceous Period some 65 million years ago. Yet, the traits that allowed them to survive that disastrous event might not save them from the current extinction crisis caused by humans.

There are seven living sea turtle species: the loggerhead, leatherback, green, Kemp’s ridley, olive ridley, hawksbill, and flatback turtles. All nest on beaches in tropical or subtropical regions, returning to very specific places again and again to lay their eggs. For example, one of the largest populations of green sea turtles make their nests at Tortuguero, Costa Rica year after year. Meanwhile, different loggerhead populations return to various sites along Florida’s coast or to distant places like Masirah Island off of the African country of Oman. Unfortunately, the reliance of sea turtles on such specific locations makes them vulnerable to any disturbance at those sites, and coastal ecosystems have long been targeted by people for development and industry. It is perhaps no wonder, then, that all seven sea turtles are listed as threatened or endangered–and historically, some species probably came ashore at other nesting sites that have long since been destroyed.

The sea turtle species that people in the U.S. are most likely to encounter is the loggerhead, females of which lay eggs about every 2-3 years, digging multiple nests over the course of late spring and summer. Each nest may contain over 120 eggs, which take about two months to hatch. Once they emerge, the baby sea turtles must make their way over the sand to the ocean–but many succumb first to seabirds and other predators. This is a natural part of the cycle of life in marine ecosystems, with young sea turtles providing an important source of food for animals higher up the food chain. The real threat to the species’ existence comes not from predators with whom they have evolved in tandem for millions of years–but from the disturbance of beach sites and other human actions.

Other sea turtles that nest on U.S. beaches–mostly along the coast of Florida–include the green and leatherback turtles. Leatherbacks are the largest members of the sea turtle family, reaching a length of five feet or more and a weight of up to 1,500 pounds (for comparison, loggerhead turtles can grow up to about 3.5 feet long). As their name suggests, leatherbacks also have a unique shell with a softer surface than that of other sea turtles. They migrate over huge distances, with some populations traveling across the Pacific Ocean from their nesting sites in Southeast Asia to feeding waters off the California coast.

Outside of the United States, important sea turtle nesting sites occur along the coasts of Mexico, Central America, the Caribbean, the islands and mainland of Southeast Asia, and other tropical regions. The only species that does not nest in the Western Hemisphere is the flatback sea turtle, which is restricted to Papua New Guinea and northern Australia. All sea turtles have a roughly similar life cycle, nesting on sandy beaches and escaping as hatchlings to the ocean, where the adults will spend almost their entire lives and play significant roles in marine environments.

Because all sea turtle species have seen a dramatic decline in numbers, many parts of the oceans have already lost the ecosystem benefits these ancient animals bring–but they remain highly important in those regions where they still thrive. Green sea turtles are one of the few animal species to feed on seagrass, dense beds of which line the shores of many coastal areas. By trimming back and removing seagrass, these herbivores stimulate new growth and prevent dead plant material from accumulating, thereby increasing ecosystem productivity. In fact, some areas where green sea turtles have been extirpated have seen seagrass die-offs as a result.

Similarly, hawksbill sea turtles play a vital role in another important ecosystem: coral reefs. Hawksbills feed on sponges that compete with corals for space, allowing the reef to grow and thrive. Leatherbacks, meanwhile, are an important predator of jellyfish in the open oceans, helping to keep jelly populations under control. The decline of leatherbacks, along with other factors, has led to a jellyfish population boom that is imperiling fish on which these stinging invertebrates feed. From coastal waters to the high seas, the disappearance of sea turtles leads to out-of-balance ecosystems and declines in other plant and animal species.

So, what are the main threats to sea turtles around the world? These large animals are at their most vulnerable as babies, and disturbance of their nesting habitat as well as harvesting of their eggs for human consumption poses an existential danger. In addition, lights from nearby urban areas or development projects can confuse baby sea turtles as they try to make their way to the ocean, leading them off course and away from the water. Protecting the habitat in and around beaches where turtles still nest is one of the most important things we can do to ensure their survival.

Once sea turtles make it to the ocean, they are still not safe from human threats, however. Many thousands of adult turtles die each year after being caught in gill nets, shrimp trawls, and other fishing gear. Although sea turtles are not the intended targets of the nets, they become tangled underwater and die slow, horrible deaths from drowning. The increased use of turtle excluder devices (TEDs) on shrimp trawls in countries like the U.S. and Mexico has helped reduce the casualties, contributing to a small population increase in the highly endangered Kemp’s ridley turtle in recent years.

Other dangers to sea turtles include plastic pollution–which poses an especial danger to leatherbacks, who eat plastic bags after mistaking them for jellyfish. Climate change also threatens to disrupt ocean currents in ways that will affect turtles and the animals and plants on which they feed. All of these problems must be addressed if sea turtles are to be saved from extinction. You can help by minimizing your use of single-use plastics, being a responsible beach tourist, and letting your elected representatives know you want to see action on climate change and the global plastics crisis. Only with enough people taking positive action can we ensure that sea turtles continue to swim in the seas, perhaps for another 100 million years or more into the future.

Photo credit: Wexor Tmg

  • The Premium Challenge

    We'll donate animal shelter meals for every correct answer:

    This week's challenge...Sea Turtles, Ancient Survivors of the Oceans, Could Soon be Extinct.

    How much do you know?

    One of our core beliefs is that education leads to positive change. That is why we have the Educational Series. To make learning more fun, we are donating meals to animal shelters for every correct answer submitted by our Premium Members!

    While everyone can study our educational materials and take our quizzes, only Premium Members will have shelter meals donated for correct answers.

Wait, there’s one more step:

Over 1,402,880 Animal Shelter Meals Donated So Far –

Upgrade to a Premium Membership to get a free No Excuse For Animal Abuse shirt, feed shelter animals with the Educational Series and Meal Wheel, sign 100’s of petitions with one-click, remove ads, and promote your favorite petitions to millions!

7 day money-back guarantee for new members. Zero risk.

Premium Membership comes with the following perks:

• Get a free No Excuse For Animal Abuse shirt.
• Feed shelter animals by spinning the Meal Wheel.
• Sign 100’s of petitions with one-click.
• Feed shelter animals with the Educational Series quizzes.
• Remove ads and vote on which petitions are displayed to millions of people.

Our Guarantee:

Cancel your subscription for any reason within 7 days and we’ll refund 100% of your money, as long as you’re a first time member.

Frequently Asked Questions:

How are the animal shelter meals donated?

We donate shelter meals through Rescue Bank because they research all shelters, maintain equitable distribution, and track the meals from their facilities all the way to the rescue groups. This ensures that the donation will be utilized in the most efficient and impacting way.

Why don’t we just donate meals without providing any perks like the Meal Wheel?

We’ve been at this since 2008 and have learned that to really make a difference, we need to get people excited and engaged. Our mission is a serious one, but our methods are playful and educational. We’re serious about doing good, but also want to make it fun.

Who are we?

We are a family of sites that works to protect animals, the environment, and more. Our sites include and We’ve been at this for over a decade and are dedicated to protecting and defending animals and the environment. If we can have some fun and improve the world, then we’re accomplishing our goal!

Try Premium!

We’ve Been Doing This for Over a Decade and Others Have Taken Notice:

7 Day Guarantee!


“Thank you SO much for the premium feature of being able to sign multiple petitions with one click. Many of us go for hours at a time signing each and every petition and crying as we read them. I have often wished for a way to sign my name on every petition because I passionately support them and they all need our voice. This is the best thing – thank you very much!” -Karilyn K., Premium Member

“This is just the most amazing wonderful service that makes me so happy! To be able to feed shelter pets is just the greatest feeling. Thanks again for this, and for all you do for the most innocent and helpless among us, the animals. I’m lovestruck.” Sandra Z., Premium Member

“I love the upgrade option and I am so glad I did enables me to stand with you and many others to fight for the justice these precious souls deserve! We are their voice!!!! And....I adore helping to feed them as well! The spin the wheel game is fun....and I like doing it everyday to help! Keep up the wonderful work....and I know....every click makes a difference!” Dorothy B., Premium Member

“I am so excited to become a Premium Member and to have one-click signing, as I was spending countless hours signing petitions...not that I mind doing it, but my goodness, there sure are a lot of them. I always hope that my signature somehow helps, because these people that abuse/torture animals, need to be put away. As you can tell, that is my passion, I have such a heart for animals, and I want to be their voice.” Darlene R., Premium Member

“Thank you so much! I love being a premium member and spinning that wheel every day, especially when I land on 4 or, best of all, 5 meals. Thank you for all you do, we are all so grateful for you.” Sandy T., Premium Member

“With deepest Aloha, You have no idea how grateful I am for you!” Jan L., Premium Member

“Thank you for the Premium Membership option. I really appreciate that I can sign multiple petitions with one click. It's great! Thank you for the work you do.” Ashley H., Premium Member

“I absolutely love the Educational Series!” Yvonne L., Premium Member

"I am a premium member and religiously sign every petition. THANK YOU for this platform. I also vote for the petition nearest my heart, sometimes voting globally, sometimes I am caught by an individual animal's plight. What gives me great pleasure is noting that almost always, the percentages have no more than a 6-7% spread. It means that, overall, everyone cares about all of the petitions ALMOST EQUALLY! LOL, I also spin that wheel, and when I get 4 or 5 meals, I dance around the room! I have long maintained that what someone does to a helpless animal, they will do to a weaker human if they think that they can get away with it. Those who abuse, no matter how many legs their victims have, should be punished to the fullest extent of the law." Rebecca E., Premium Member

"I LOVE LOVE LOVE my Premium Membership! Everything and anything I can do to help animals and contribute to justice in the world makes me very happy!" Jan L., Premium Member

"Thank you, I love what you do. My friends and I love the membership because we can sign so many more petitions that we may never had heard of. Keep up the good work." Virginia G., Premium Member

Still have questions? Email us:

[easy-social-share buttons=”facebook,mail” morebutton=”1″ counters=0 fullwidth=”yes” query=”yes”]
Nick Engelfried Writes About Animals, the Environment, and Conservation for the ForceChange network

Skip to toolbar