Up Close and Personal With… Sea Turtles

It seems that everyone loves sea turtles with their slow, relaxed swim, gentle nature and intricately patterned shells; all things which make them the perfect species to want to swim or dive with. Yet do we really know how turtles live their lives? How humans threaten them and what we can do to help? Turtles have lived on this earth for 110 million years, outliving the asteroid which made dinosaurs and 75% of Earth’s plant and animal life extinct as our planet entered nuclear winter conditions. Yet after surviving these astonishing global changes in the past, we mere humans are threatening turtles to the point of extinction with our array of invasive coastal activities as well as our indirect actions regarding consumption of fossil fuels and plastic.

Today, there are seven different species of sea turtle which live in a variety of coastal areas including shallow sea grass beds and the open ocean as these individuals are known to travel enormous distances in their lifetime. Many loggerhead turtles make the intrepid crossing from Japan across the Pacific Ocean to Mexico simply to forage before returning home to lay eggs in the sand. One tagged female hit the road, or waves, and travelled 12,000 miles in her lifetime! Most crucially however, some spend their days meandering around coral reefs, snacking on sea sponges, keeping their population numbers low to stop them from out-competing our beautiful rainbow of corals. This role as a sea gardener is essential as our reefs support a mighty 25% of our planet’s marine life, much of which our fishing industries benefit from such as tuna and lobster.

Turtles have a highly risky life as juveniles as the eggs nestled in the sand are a perfect pit stop for lunch for seabirds, racoons, ants and crabs. Even once hatched and stumbling towards the sea, they still pose a fun target practice for these predators. When they become fully grown however, turtles have relatively few worries as their only predator is the occasionally large shark. Once again though, humans have hindered this happy routine and now two of the seven species of turtles are critically endangered, meaning that they are at a high risk of extinction while some other species are data deficient, meaning we really have no idea how healthy their population is or how many are left.

Human activities have worsened the plight of baby turtles as our deckchairs, umbrellas and heavy feet litter their nests and make the journey to the sea even more difficult. Female turtles return at night to their beach of birth to lay their eggs, yet if the beach is too noisy, busy or there is a general hubbub from late evening party goers, she will simply turn back to sea and the eggs will never be laid. Our construction of sea walls and jetties may also inhibit the female being able to reach the shore yet once on land, she lays the eggs in the sand before heading back out to feed. A major problem lies here as human driven climate change is causing temperatures to rise. This is proving an unexpected yet detrimental problem to sea turtles as the temperature of the sand actually influences whether the baby that peeks its way out of the eggshell is male or female. In an extreme case, the sand in Raine Island, Australia is now so warm that 99% of eggs are hatching as female, making reproduction and population growth almost impossible. Even on beaches with cool sand, the increased ferocity of ocean storms due to climate change is leading to storm surges powering their way up our shores which is flooding turtle nests which contain between 100 and 200 eggs.

For those lucky hatchlings which survive storm surges and the hungry eyes of predators, they now have human obstacles to contend with. Hatchlings emerge at night, pushing their way up through the sand before being guided towards the sea by the natural light on the ocean’s horizon, a pretty incredible evolutionary trait! However, as our beachfronts become prime locations for tourism and expensive housing developments, they also become filled with streetlights, car lights and hotel lights. These artificial lights understandably confuse baby turtles in their first 30 seconds of life on this planet and mistaking our artificial lights for the ocean’s bright horizon, they actually turn away from the waves and head inland where they stumble across hungry urban predators like racoons and foxes, speeding cars and a lack of turtle friendly food. For those heading in the right direction, our deckchairs and beach umbrellas left behind from the day before provide huge obstacles for these tiny tots to navigate, increasing their time on the sand where hidden crabs are keeping a close eye on them. Even simple tyre tracks can cause a big delay for these hatchlings; this is their first time walking after all!

Once lazily gliding through the water, our waste becomes an issue. Plastic, as usual, is a major problem here with thin bags, film and even balloons being almost identical to a turtle’s favourite jellyfish dinner. These graceful swimmers may also glide right through our plastic junkyard and become ensnared in our trash, as seen with the famous turtle Peanut who had a beer six pack ring stuck around her middle, limiting the growth of her shell and causing it to become the shape of an ‘eight’ or, as her name suggests, a peanut. The deformities to her shell mean that she is not aerodynamic which makes it much harder to escape any predators, while those turtles ingesting plastic by mistake suffer from low energy and blocked digestive tracts.

Turtles are also prey for our large plastic fishing nets and are often caught as bycatch by many fishing vessels. In fact, 40% of all animals caught by fisheries are discarded as trash as they are not the target species. Turtles are particularly attracted to long lines; kilometres of almost invisible thin line which are covered in thousands of baited hooks and small lights. The lights attract feeding animals up from the deep ocean at night and when they bite down on their midnight snack, they become trapped on one of the many hooks. Some solutions have been implemented to solve this issue of bycatch as shrimp trawling nets in America are now by law required to be fitted with turtle excluder devices (TEDs). These are small gates at one end of the shrimp net and once large heavy animals such as turtles but also sharks bump against them, the gate opens and they can escape back into the wide ocean. The final threat to sea turtles in our seemingly never-ending list is illegal trade where sadly, turtles are the direct target of human industries. Hawksbill turtles have declined by 90% in the last 100 years as their exquisite shell is often used to make jewellery, combs and other products. In 1977, the trade of hawksbill shells was prohibited globally, however agreeing to this law was voluntary and it took some countries many years to ratify. Whilst almost all countries have now signed this piece of legislation, there remain large stockpiles of shells in Asian and Latin American countries which make it hard to know whether products sold have come from the old stockpiles or from freshly caught turtles. The popularity of turtle meat and eggs in these countries has also proved hard to shift.

So, I think we can agree that turtles face an unfair enormous brunt of our damaging activities but there are things you can do to help. If you are lucky enough to live near turtle nesting sites, you should avoid nesting beaches in nesting season, particularly at night when females come ashore to lay eggs. If you have dug holes or made sandcastles on the beach, much to your child’s dismay, these should be dismantled at the end of the day so they don’t provide obstacles as hatchlings take their first stumble towards the sea. You can also perform beach cleans, be alert when boating in coastal areas and avoid having night-time fires on these beaches as hatchlings mistake the light for the ocean horizon. If you don’t live near turtles’ favourite ocean spots, you can still help them out by choosing seafood which has been caught using sustainable methods which reduces bycatch and also reduce your consumption of single use plastic which can easily circumnavigate the globe and may end up on the doorstep of one of these beautiful creatures. If you want to get more involved or maybe want to see a turtle for the first time, there are many charities open to volunteers who could be doing anything from night time beach patrols to making sure the hatchlings are protected from predators as they emerge to collecting data on local turtle populations which provides evidence as to why we need to increase marine protected areas. These types of holiday activities are much more beneficial to wildlife than your regular boat trips which may actually disturb the animal you want to see. With these creatures surviving millions of years of drastic environmental changes, we simply cannot let their population crumble before our eyes due to our unthoughtful actions; so which change will you make first?

By Neve McCracken-Heywood