Affected by tourism and rising temperatures, sea turtles in Greece are in peril

Volunteers Andréa Briançon, Kaitlin Edwards and Jackie Nord treat sea turtle Hydra for flipper injuries.
Photo by Gwendolyn Schanker

Story and video by Gwendolyn Schanker ·

GLYFADA, Greece – It’s a sunny, slightly breezy day in Anavyssos, Greece, and loggerhead sea turtle Angeliki is ready to return to her home in the ocean.

Angeliki, whose name means “angel,” was found off the coast of the Greek island Lefkada in December 2016 with a head injury that was most likely human-inflicted. She was retrieved – with the help of the Lefkas Animal Welfare Society  – by members from ARCHELON, the Sea Turtle Protection Society of Greece. She has spent more than six months rehabilitating in a tank where she was fed and cared for daily. Now, on a gorgeous afternoon in early June, she finds herself aboard a small boat speeding away from the Aqua Divers’ Club in Anavyssos.

“She’s ready to go now, basically. She’s swimming fine,” said Pavlos Tsaros, rescue network coordinator at ARCHELON, as he gives a quick rundown of Angeliki’s story to the boat captain at the Aqua Divers Club and two diving students – a mother and her son – who have tagged along for the release. Tsaros said Angeliki weighed around 51 pounds at the time of release, and estimates her age to be between 15 and 20 years old.

Ten minutes later, Angeliki is gently pushed off the side of the boat and swims swiftly away, probably never to be seen again by anyone aboard. Loggerhead sea turtles can live to be over 100 years old, so she has a lot of life ahead of her.

“She has two tags, so if she comes to rest on the beach one day, probably we’ll know about it,” Tsaros said. Other than that, he said, “all we can do is wish her the best.”

Injuries like the one Angeliki has overcome aren’t uncommon. According to the National Oceanic and Atmospheric Administration, the Mediterranean population of loggerhead sea turtles, or Caretta caretta, is classified under the Endangered Species Act as endangered, while loggerheads in other geographic areas – including the Northwest Atlantic Ocean off the East Coast of the U.S. – are listed as threatened.

A report from the International Union of Conservation of Nature estimates that there are between 2,000 and 5,000 nesting females in Greece and also acknowledges a rapid drop in nesting frequency at the end of the twentieth century. According to ARCHELON’s website, for  example, there was a 49 percent decrease in nesting near Crete between 2000 and 2014 alone. Though exact numbers are difficult to trace, the loss of sea turtles in Greece is decidedly dramatic.

“It’s very difficult to estimate the population, but we know that we lose a lot of them every year,” Tsaros said.

The list of threats the loggerheads face is long, from tourist development – the Greek island of Zakynthos is the largest nesting ground for sea turtles in the Mediterranean Sea and is also a rapidly developing tourist destination – to fishermen, who harm up to 40,000 sea turtles annually by accidentally catching them in their fishing gear. Fishermen have also been known to cause intentional injury out of fear of their size or so they don’t compete with the turtles for their fish haul; in fact, purposefully hurting these animals accounts for up to a third of the injuries that employees and volunteers at ARCHELON Rescue Centre treat.

“[Fishermen] might think they are scary animals because they are quite big,” Tsaros said of the sea turtles, which, once they reach full maturity, can weigh up to 1,000 pounds and reach up to 9 feet in length. “In human society, we tend to kill the thing before we understand it.”

Angeliki, for example, was most likely the victim of a purposeful blow to the head. “The more I look at her, the more I think it’s probably an axe and not an accident,” said Tsaros.

Now, loggerhead sea turtles have begun to grapple with an additional threat: climate change. The turtles are highly sensitive to temperature changes both on land, where they nest, and in the water, where they live. This means that rising temperatures as a result of global climate change are likely to have a dramatic impact on turtles’ lives.

ARCHELON, which for 30 years has been working to study and protect sea turtles in Greece through research, rehabilitation, and environmental education, has a handful of employees but is staffed largely by its 500 volunteers. Some spend time at the rescue center caring for the injured turtles and preparing them for release, and others work summers on the beaches where the turtles nest: Zakynthos, Crete, or the Southern Greek region of Peloponnese.

“Without volunteers, we wouldn’t be able to do the job,” Tsaros said.

ARCHELON’s volunteers come from all different countries to work with the endangered animals, either because they are interested in a career in biology or simply because they are passionate about environmental preservation and education.

“If there’s not enough people to help, [sea turtles] will disappear,” said Andréa Briançon, 21, a volunteer from France who has been working at the rescue center in Glyfada for about six weeks. She lists off the many challenges sea turtles face, from fishermen to climate change to plastic floating in the ocean. “In the ecosystem, we need turtle[s]. It’s important to protect them.”

Rescue Network Coordinator Pavlos Tsaros works with Andréa Briançon to measure sea turtle Angeliki before her release.
Photo by Gwendolyn Schanker

Sea turtles and global change

Sea turtles are some of the oldest animals on the planet. According to the University of Miami, fossil records of turtles date back more than 200 million years.

For millions of years, sea turtles have played an important role in helping to maintain the health of the oceanographic environment they reside in. According to a report from nonprofit organization Oceana, sea turtles’ foraging technique allows for greater distribution of nutrients in the water and on the land where they nest. Furthermore, many loggerheads play host to epibionts, small organisms like barnacles that live on the surface of their shell.

Sea turtles are especially important to scientists as they are an ectothermic species, which means that they are sensitive to temperature changes. In warmer weather, sea turtles are much more likely to lay female eggs than male, which over time, will lead to a female-dominated sex ratio in the sea turtle population and could ultimately speed up the possibility of species extinction.

Vasiliki Almpanidou, a Ph.D. student in the lab of Antonios Mazaris, a professor at Aristotle University of Thessaloniki who studies ecological systems through modeling, said she has already observed this impact in real time. As both water and atmospheric temperatures have risen, loggerheads in the Mediterranean have begun to shift their nesting patterns.

“We have observed an earlier and earlier onset of nesting,” Almpanidou said. “This gives [the turtles] potential to lay their eggs when the temperature is not very high.”

For her Ph.D. research, Almpanidou uses data collected in the field – on Zakynthos or other popular nesting sites – to create ecological models that predict the future distribution of sea turtle populations. She said sea turtles have also begun to shift their nesting patterns on a micro scale: for example, by moving to beaches with darker and less hot sand.

Almpanidou said her research findings indicate that most current nesting sites will continue to be used by sea turtles, but other sites may emerge as the climate continues to change. Findings from her research and other work in Mazaris’ lab make it possible to monitor and protect those areas sooner rather than later.

“We will have some indications that some other nesting sites are going to be suitable in the future,” Almpanidou said. “They give us some direction in order to strengthen the protection and our conservation actions. We can also put some effort in order to monitor these sites.”  

She added that ongoing study of sea turtles’ susceptibility to change will not only benefit the turtles themselves, but it may also be helpful for understanding how a multitude of other organisms will be affected by the warming climate.

A sign on the wall of the room that houses most of the sea turtles’ tanks gives a reminder of what the ARCHELON Rescue Centre are trying to achieve.
Photo by Gwendolyn Schanker

“If we monitor the changes in their biology and ecology based on changes in temperatures, we can have a more holistic view of the impact of climate change,” Almpanidou said.

Facing additional challenges

Of course, climate change isn’t the only challenge sea turtles have to grapple with. Another important issue is how the tourist industry on the islands is impacting sea turtles’ ability to survive. Babies rely on the stars to find their way to their new home in the ocean. If there is too much artificial light on the nesting beach, the hatchlings may become disoriented and move inland instead.

“When the hatchling emerge from their nest, they have to find the sea and they usually orient with the stars,” said Chrysoula Gkazinou, an undergraduate research fellow in Mazaris’ lab who has previously volunteered at ARCHELON on Zakynthos island. “When there is so much light behind them from the beach and all the hotels and bars, they go to [that] direction and basically they die. If they stay there long they lose their strength and become dehydrated.”

As a member of the only sea turtle research lab in Thessaloniki, Gkazinou is frustrated with the lack of attention to the impact humans are having on the sea turtle population in Greece.

“These animals were here before us and they were doing good, and then we came and destroyed the environment,” she said.

Environmental education is a key aspect of the work being done at ARCHELON, Tsaros said.

Volunteers at the rescue center give tours to school groups nearly every day, and also share information about what they’re working on through social media. Tsaros said environmental education is equally important to working with the sea turtles directly in helping preserve the population.

“To make things change, you have to inform people and educate them,” Tsaros said.

Morning rounds at ARCHELON

For the volunteers currently stationed at ARCHELON, the day begins around 6:30 a.m, when one volunteer emerges from a railroad-car-turned-dorm-room to take notes on the behavior of the turtles, each of whom lives in an individual tank. Shortly after, the rest of the team rises and sets to their tasks of cleaning the turtle tanks, feeding the animals and treating those who have injuries.

Sea turtles that are new to the center receive additional antibiotics through a drip treatment in addition to their daily feedings. Jackie Nord, 24, is careful as she massages the left side of sea turtle Maria’s neck before injecting the drip.

Volunteer Ally Iheanacha cleans the tank of sea turtle Patrick at the ARCHELON Rescue Centre in Glyfada.
Photo by Gwendolyn Schanker

“When they first get here, they get a line of antibiotics and rehydration drips,” explained Nord, a native of Chicago who recently got her master’s degree from Green Mountain College in Vermont. The treatment usually lasts for about a week, but “Maria here has a head injury, so she’s been on it for two weeks.”

A few feet away, Ally Iheanacha, 21, asks for help from two other volunteers to remove Christina – the rescue center’s largest inhabitant – before beginning to scrub her tank. Iheanacha, who is from Wales, is ARCHELON’s newest recruit. She arrived only a week ago and is still learning the ropes.

It’s a quiet, tranquil environment as the volunteers go about their work, sometimes pausing to ask questions in English but sometimes in French, Spanish or Greek. The quiet is broken around 9 a.m. when a bus full of schoolchildren arrives.

Christos Giannopoulos, a native of Athens who commutes every day to Glyfada, walks around the 20 or so tanks that the turtles inhabit with several small buckets of fish. He said the feeding is his favorite part of the important work he is doing each day.  

“I help turtles and animals in general to become healthier and live in their natural environment again. I’m happy to be part of that,” said Giannopoulos, 18, mentioning with a smile that one of the turtles at the center is also named Christos.

Tsaros, originally a volunteer himself, is thankful to have the help as he goes about his busy day. He enjoys working alongside both the volunteers and the sea turtles, which he said are, in some ways, smarter than humans.

“They’re very strange animals,” he said. “They have less brain but they probably use it better. We have more brain, but we use it less.”