The Sea Turtles of Sabah

The animal

The transboundary conservation zone

The beaches and reefs of eastern Sabah serve as a major refuge for migrating populations of endangered green and hawksbill turtles. You can observe the strict conservation protocols on the nesting sands of Selingan Island or dive the steep volcanic walls of Sipadan. Whether you watch hatchlings emerge from the beach or swim parallel to giant adults, you will be glad you made the journey.

Sabah sits at the centre of marine turtle activity in Southeast Asia. The geography creates the right conditions for them. The deep oceanic currents hitting the islands generate nutrient upwellings that sustain dense algal growth and sponges. The sandy island beaches provide the gradient and temperature required for their eggs to incubate.

Because marine turtles are highly migratory, they require international cooperation. In 1996, Malaysia and the Philippines signed an agreement creating the Turtle Islands Heritage Protected Area. This transboundary zone joins 3 islands in Sabah with 6 in the Philippines. It coordinates conservation strategies and anti-poaching enforcement across the maritime border.

Green and hawksbill turtles

The green turtle (Chelonia mydas) is listed globally as Endangered by the IUCN. It is a large herbivore that feeds extensively on seagrasses and algae. It accounts for the vast majority of the nesting females at the Turtle Islands Park. The adults frequently exceed a metre in carapace length.

The hawksbill turtle (Eretmochelys imbricata) is smaller and is listed as Critically Endangered. It has a narrow beak suited to extracting sponges and tunicates from the coral matrix. By eating sponges that would otherwise out-compete corals for space the hawksbill plays a vital role in keeping the reef healthy.

The nesting beach sands

Nesting occurs year-round across the region. The green turtles experience a heavy seasonal peak between July and October. The hawksbills concentrate their nesting heavily within the Turtle Islands Park. Their peak activity runs from February to April.

The females emerge from the sea almost exclusively after dusk. They dig a deep chamber in the sand and lay their clutch. A green turtle clutch numbers roughly 40 to 120 eggs. A hawksbill clutch is much larger and averages about 118 to 126 eggs. The incubation relies entirely on the ambient temperature of the beach sand and lasts between 49 and 60 days.

Like all sea turtles they lack sex chromosomes. The sex of the hatchlings is determined entirely by the temperature of the nest during the middle third of the incubation. A sand temperature of 29.0 °C produces an equal ratio of males to females. Warmer sand produces females.

The Selingan Island hatchery

The Turtle Islands Park covers 1,740 hectares and includes Pulau Selingan, Pulau Bakkungan Kechil and Pulau Gulisaan. Only Selingan accommodates overnight guests. The capacity is strictly capped at 50 people a night to minimise the footprint on the beach.

At Selingan, rangers move eggs from nesting beaches into protected hatcheries, a method called ex-situ conservation. In areas threatened by human poaching or natural predators like monitor lizards the eggs are manually relocated to secure fenced hatcheries. The movement must happen within hours of the eggs being laid to prevent the delicate embryonic membranes tearing. Critics of centralised hatcheries warn that unshaded nests become warmer as global temperatures rise, producing more female hatchlings. Selingan's managed visits balance conservation income against the disturbance that visitors bring to nesting turtles.

The ecotourism experience is structured. After dark you wait at the visitor centre or cafeteria until the ranger calls your group. When a Sabah Parks ranger locates a female that has entered her nesting trance, the entire 50-person group is summoned. You all observe just 1 turtle to reduce the disruption to the wider population. The ranger collects the eggs and the group follows to watch them reburied in the hatchery.

You then move to the shoreline to watch newly hatched turtles being released into the surf. Once hatchlings emerge from the sand they must immediately find their way to the ocean and swim continuously for up to 24 hours to escape nearshore waters. This frantic exertion relies entirely on a finite internal energy reserve provided by the internalised yolk sac. To locate the ocean they rely on visual cues and move toward the brightest horizon which is the moonlight reflecting off the surf. Coastal light pollution overwhelms these cues and causes severe disorientation. This is why artificial lights on the nesting beach are strictly prohibited and why the hatchlings must be released immediately upon emerging.

The island is a working conservation outpost with comfortable rooms for a remote location. The ranger-led routine protects nesting females and their hatchlings.

The eastern dive sites

If you want an unmanaged encounter, the offshore reefs offer some of the highest turtle densities in the world. Sipadan is a volcanic pinnacle rising 600 metres from the seabed. Green and hawksbill turtles are present on nearly every dive. You find them grazing the walls or resting in coral alcoves.

Be sure to plan ahead if you want to dive there. Sabah Parks issues 254 Sipadan permits a day. Advanced Open Water certification has been required to dive at Sipadan since October 2022. The island is closed every November and reopens on 1 December. Snorkellers also need a permit. If you pre-book on a dive package with the right resort, a day's diving at Sipadan can be guaranteed. Remember to allow 24 hours between the last dive and a flight.

Mabul and Kapalai sit nearby and offer a completely different topography. Mabul features sloping sandy reefs and artificial structures. Kapalai rests on the shallow Ligitan Reef. The turtles cruise through the structures and rest in the shallows.

Further north in the Sulu Sea Lankayan Island sits within the Sugud Islands Marine Conservation Area. It features its own sea turtle hatchery and offers a quieter alternative to Selingan with stays available outside its annual January and February closure. Down in the Semporna Priority Conservation Area the islands of Mataking and Pom Pom host important foraging grounds with active independent monitoring.

The Sipadan turtle population

The turtles at Sipadan tolerate divers because the marine park is strictly enforced and they are not hunted there. They have acclimatised to the daily presence of visitors over decades.

The sheer number of turtles at Sipadan is remarkable. A famous 2014 study by Christianen detailed how successful conservation can lead to a density paradox where hyper-abundant turtles overgraze seagrass beds. While Sipadan shares that density the actual study took place at Derawan Island in Indonesia. The turtles at Sipadan are supported by the nutrient upwellings of the deep oceanic walls.

Sipadan also holds Turtle Cavern and Turtle Tomb. The entrance to Turtle Cavern lies at a depth of roughly 18 metres and leads into a bell-shaped tunnel. The fine white dust on the floor of the inner chambers is composed of the skeletal remains of turtles. They accidentally entered the cavern and drowned after becoming disoriented in the dark. Penetrating the tomb strictly requires full technical cave-diving certification. No responsible operator takes standard recreational divers inside.

Marine threats and diving rules

When you meet a turtle underwater, your position matters. Never approach one head-on because you block its path to the surface for air. Swim parallel to its trajectory. Touching, riding or holding the carapace is a severe violation of the rules and results in immediate expulsion from the park.

If you are a photographer, you must manage your strobes. Turtles lack eyelids. High-intensity rapid-fire strobe flashes can temporarily blind them and cause acute distress. In the shallows ambient light is usually sufficient.

The turtles face immense pressures away from the protected beaches. Egg poaching remains a serious issue driven by black market demand. Because the protected area shares a porous maritime border, poachers frequently raid unprotected beaches across the region. They smuggle the eggs into towns like Sandakan where they are sold surreptitiously in local markets or distributed through online social media networks.

An even bigger threat happens offshore. Commercial shrimp trawlers drag wide nets across the seabed and sweep up feeding turtles. Unable to surface, they drown. The Sabah-based Marine Research Foundation estimates thousands die this way annually.

To solve this the foundation champions Turtle Excluder Devices. A metal grid is sewn into the neck of the trawl net. Shrimp pass through but turtles strike the grid and are ejected through an escape flap. These devices eject the vast majority of turtles without harming the fishermen's yield.

The dive reservations team

If the night turtle programme or the wall diving is what you are coming for, tell the team which matters most. Send your dates, your party size and your dive certification level. The team will build an itinerary around the right resort and secure the permits you need.

--- Sources referenced on this page: WWF, BIMP-EAGA, Sabah Parks, IUCN, Journal of the Marine Biological Association of the United Kingdom, Frontiers in Marine Science, Chelonian Conservation and Biology, Marine Research Foundation. Facts verified 9 September 2026.