The World’s Oldest Sea Turtle: A Century of Survival

Sea turtles are renowned for being among the oldest animals living today, having been around for 110 million years. Known as marine reptiles, sea turtles are one of only four reptiles that have adapted to life in the sea along with crocodiles, marine iguanas, and sea snakes. But, how long do sea turtles live? Sea turtles don’t mature until they are around 20 years old, so it’s no surprise that some of them can live for a long time. So, just how old is the world’s oldest sea turtle? Continue reading to discover the oldest sea turtles and how they compare to other turtle species.

Sea Turtles: An Overview

Sea turtles can easily be distinguished from other turtles by their limbs which are flippers. The shape of their shell, which is long and tapered at each end, prevents sea turtles from retracting their head for protection. There are seven extant species of sea turtles- leatherback, hawksbill, olive ridley, Kemp’s ridley, green, loggerhead, and flatback.  Sea turtles are found in every ocean around the world, except for polar regions. Some sea turtles have been known to migrate extremely long distances.

Most sea turtles are omnivores that eat seaweed, jellyfish, squid, and barnacles. They use their front flippers to seize and hold their food. Sea turtles are excellent swimmers and can spend up to 40 minutes underwater while foraging for food.

Sea turtles spend the majority of their lives at sea. Only the females come onto land, and even then only to lay their eggs. Females come onto the beach under the cover of darkness and dig a hole in the sand using their flippers. They then lay a clutch of eggs (usually between 60 and 180), covering them with sand. Female sea turtles make several decoy nests to protect their eggs from predators. They then return to the sea without a backward glance.

Hatchlings emerge after 60 days and head for the sea.  Once they’ve reached the sea they then swim out into the open water where they will remain for many years until they have reached maturity.  Only once they are mature do they then return to the waters around the shoreline to begin breeding.

Sea Turtle Lifespan

How long do sea turtles live? The lifespan of turtles ranges from 30 to 80 years depending on the species. However, a lot of guesswork is involved when trying to age sea turtles as they spend much of their time at sea and there is no truly reliable method of ageing them.

Kemp’s ridleys are the smallest sea turtles and though not a lot is known about their lifespan, it is estimated to be 30 years. The lifespan of olive ridley sea turtles is around 50 years, while the hawksbill is 50 to 60 years. Green turtles have an average lifespan of 70 years, while the flatback and loggerheads can also live for 70 to 80 years. Leatherback sea turtles are the largest sea turtles and it is estimated that their lifespan is more than 50 years, but little is truly known about their longevity. The magnificent marine creatures, weighing up to 2000 pounds, also dive deeper and travel farther than any of the others. They have been recorded traveling 10,000 miles to their nesting sites and diving to depths of 4,000 feet.

The World’s Oldest Sea Turtle

The oldest sea turtle in the world was likely around 100 years old. A leatherback sea turtle that washed up on the beach in Gwynedd, Wales in 1988 was the largest sea turtle ever recorded at a massive 2,019 pounds. The turtle was estimated to be around 100 years old. Scientists determined the turtle’s age by its massive size. This account is one of the more reliable records of the oldest sea turtle in the world, which was preserved and has been on display in the National Museum of Wales since 1990.

The oldest living land animal, however, is a Seychelles giant tortoise (Aldabrachelys gigantea hololissa) named Jonathan who is estimated to be 192 years old (2025) and lives on Saint Helena’s Island where he is a celebrity!

Conservation: Are Sea Turtles Under Threat?

Sadly, all seven species of sea turtles are considered to be under threat – loggerheads and green sea turtles are considered endangered, while hawksbill and Kemp’s ridley are critically endangered. Leatherbacks and olive ridley sea turtles are classed as vulnerable.  Although there is no data on the IUCN red list for flatback turtles, they are considered an endangered species in their native Australia.

The only natural predators of adult sea turtles are crocodiles and large sharks, predators play a part in their declining numbers as the eggs and hatchlings are at risk from crabs, birds, fish, and raccoons.. These predators frequently prey on young sea turtles with estimates of only 1 in 1,000 to 1 in 10,000 making it to adulthood.

Unfortunately, natural predators aren’t the only things that sea turtles have to worry about as we humans are a large threat to them as well.  Sea turtles are often caught up in fishing nets as bycatch and plastic waste and pollution is a problem too.  Sea turtles will mistake plastic for food and eat it which causes illness and death. Climate change is another factor affecting these majestic animals as their nesting sites are quickly disappearing.