The Green Turtle, Chelonia mydas, has officially been moved from Endangered to Least Concern on the IUCN Red List, the world's largest list of globally threatened species. This is the first time since their initial assessment in 19826, and is a huge achievement for global conservation efforts. But what does this mean for Turtle Island exactly?
Why are turtles important for Koh Tao?
Koh Tao, or Turtle Island, is an extremely popular destination for holiday-makers, scuba divers, and nature enthusiasts worldwide 1. It is estimated that scuba diving alone attracts between 300,000 and 500,000 tourists annually 2, providing income for approximately 8,000 people living on the island 3. This strong economic reliance on marine tourism highlights the importance of protecting ocean ecosystems and ensuring their continued health. After all, healthier reefs support better nature and diving experiences!
In the context of a rapidly changing climate, much of the tropical marine life in the Gulf of Thailand has experienced significant declines. However, as of December 2024, the Green Sea Turtle (Chelonia mydas) has been reclassified from Endangered to Least Concern. This substantial conservation success provides strong motivation to continue and expand marine conservation efforts.
Ecologically, sea turtles play a vital role in maintaining the health of Koh Tao’s marine ecosystems. Green sea turtles, in particular, consume algae and seagrass as key components of their diet. Algae can grow rapidly and, in the nutrient-rich waters surrounding Koh Tao, may outcompete corals for space. Through their herbivorous feeding behaviour, turtles help control algal growth, freeing up substrate for slower-growing corals to settle. This process supports coral recovery and, in turn, promotes greater reef complexity and fish diversity across Koh Tao’s reefs.
The long-distance migrations undertaken by sea turtles also facilitate the exchange of genetic material between geographically distant populations, thereby enhancing genetic diversity around Koh Tao. This genetic diversity is critical for species resilience, particularly in the context of anthropogenically driven climate change. By increasing adaptive potential, genetic variation helps buffer populations against threats such as disease outbreaks, thermal stress, and shifting population dynamics, reducing the risk of ecosystem collapse.
What are the threats to sea turtles?
Sea turtles face a range of significant threats, including overfishing, collisions with boat propellers that can cause severe injury or mortality, and plastic pollution. Plastics are frequently mistaken for food and ingested by turtles, leading to serious health consequences and often death.
Climate change and increased surface temperatures also have a dramatic impact on turtle populations. When turtles lay their eggs, the temperature of the surrounding sand plays a crucial role in sex determination of the offspring. Warmer temperatures (around 31°C) trigger enzymes which produce oestrogen, resulting in female offspring, however in cooler temperatures (around 27.7°C) the oestrogen producing enzymes are not triggered, thus producing male offspring 7. With global temperatures increasing, we are observing a disproportionately high number of females in populations; making it increasingly hard for individuals to find suitable mating pairs. By reducing our carbon emissions, and mitigating rising temperatures, we can hopefully restore the correct sex ratios to keep populations thriving.
Despite international protection measures, such as the Memorandum of Understanding on the Conservation and Management of Marine Turtles and their Habitats of the Indian Ocean and South-East Asia (IOSEA MoU)4, sea turtles continue to be illegally hunted for their shells (used in jewellery and accessories), meat, and eggs (sometimes consumed due to beliefs in their aphrodisiac properties). This illegal exploitation places additional pressure on already vulnerable global turtle populations, particularly in coastal regions with individuals facing economic hardship. In response, several conservation organisations are working collaboratively with former poachers, offering alternative livelihoods through employment in turtle conservation programmes. These initiatives aim to support both economic security for local communities and long-term ecological sustainability for sea turtle populations 5.
What are the methods of turtle conservation?
The protection of all sea turtles can be an extremely time-consuming and strenuous form of work. Physical methods often include long beach patrols, egg collection, in situ turtle first aid, incubating eggs in man-made nurseries, and releasing hatchlings on beaches. Scientists may also add trackers to understand movement patterns in order to comprehend changes in behaviour as a result of changing environmental cues.
Broader, large-scale conservation efforts include changes to government laws and regulations, such as measures to reduce bycatch and to restrict or prohibit the trade of sea turtles and their products.
Where to find turtles in Koh Tao
Green Sea Turtles may be found at many of the dive sites around Koh Tao including White Rock, Twins, Hin Pee Wee, Hin Wong, Shark Island and Aow Leuk Bay.
How is Roctopus helping turtle species?
The Roctopus ecoTrust is extremely passionate about doing all we can to help these amazing creatures. Clean-up dives as well as beach cleans reduce plastic on our beaches and in our oceans, granting increased space for safe turtle nesting as well as reducing the plastic likely to be consumed by turtles. This data is also passed onto the Government of Thailand to provide up-to-date scientific information about plastic waste on the island, potentially influencing future governmental change. We also offer numerous high-quality ecological courses spanning from 1 day to three months, equipping individuals with knowledge to contribute towards marine conservation in whatever capacity they wish!
However you choose to aid in conservation efforts, we’re sure you agree that this new classification is a brilliant next step for the protection of vulnerable species all around the world, and here at ecoTrust, we’re positive we’ll be seeing Green Turtles for years to come!
References
1.Tapsuwan S, Rongrongmuang W. Climate change perception of the dive tourism industry in Koh Tao island, Thailand. Journal of Outdoor Recreation and Tourism. 2015;11:58-63. doi:https://doi.org/10.1016/j.jort.2015.06.005
2.The Biodiversity Finance Initiative. Koh Tao: A Model for Sustainable Tourism and Coral Reef Conservation. BIOFIN. Published October 2, 2024. Accessed December 16, 2025. https://www.biofin.org/news-and-media/koh-tao-model-sustainable-tourism-and-coral-reef-conservation
3.Koh Tao a Complete Guide. People & Culture. KOH TAO : a Complete Guide. Accessed December 16, 2025. https://www.kohtaocompleteguide.com/fact/people-culture/
4.WWF. Thailand signs key regional marine turtle conservation agreement. Panda.org. Published May 18, 2004. Accessed December 16, 2025. https://wwf.panda.org/es/?13203/Thailand-signs-key-regional-marine-turtle-conservation-agreement
5.Ocean Sole. Join Ocean Sole’s Mission to Save Sea Turtles. Ocean Sole. Published August 24, 2025. Accessed December 16, 2025. https://oceansole.com/blogs/news/join-ocean-sole-s-mission-to-save-sea-turtles?srsltid=AfmBOopE_RhwT-biSzlwnwOcRcUdlLmygU-x6Whm6L8CRAnlh6avZQzs
6. Wallace BP, Broderick AC. Chelonia mydas. IUCN Red List of Threatened Species. 2025; e.T4615A285108125. doi:10.2305/IUCN.UK.2025-2.RLTS.T4615A285108125. Accessed December 16, 2025.
7. NOAA. What causes a sea turtle to be born male or female? Noaa.gov. Published June 16, 2024. Accessed December 16, 2025. https://oceanservice.noaa.gov/facts/temperature-dependent.html
Author: Jaimie Smithson, MSc and EcoDivemaster
Jaimie holding a baby Leatherback Sea Turtle while on an internship in Costa Rica.
