Maldives Sea Turtle Rescue & Rehabilitation

Sex Determination of Sea Turtle Hatchlings

This month, we were pleased to receive photo ID submissions for two male turtles (one green, one hawksbill), and both were found to be new additions to our database. In recent years, we have been recording sightings of fewer numbers of males, and we think this might be due to increasing global temperatures.

Unusually, the sex of most species of turtles (and some other reptiles) is determined after fertilisation. It is the temperature of the incubating eggs that establishes whether the hatchlings will be male or female (warmer sand produces more females).

• Incubation <27.7°C, the turtle hatchlings will be male.
• Incubation >31°C, the hatchlings will be female.
• Variable temperatures produce a mix of both male and female hatchlings.

As the Earth experiences climate change, increased temperatures will likely result in fewer male turtle hatchlings, which could be devastating for the future survival of sea turtles.

Sea Turtle Nest Protection

• Nest #5 (10 March, Villa #204) – Hatched successfully on 6 May (57-day incubation). Signs of emergence were observed on our nest camera (at 22:50h) so we were able to mobilise a small team to closely observe the full process. Subsequent excavation of the nest revealed one healthy hatchling (immediately released) amongst 89 shells and four unhatched eggs (96% hatching success rate, 95% emergence success). The top of the egg chamber was measured at a depth of 60cm, while the bottom of the egg chamber was 76cm below the surface.
• Nest #6 (20 March, Villa #201) – Hatched successfully on 11 May (53-day incubation). Unfortunately, emergence occurred in a turtlecam blind spot, so the time was estimated at 2am. The next morning, two hatchlings were found disoriented under vegetation, and two further hatchlings were uncovered in the empty nest (all four were successfully released from the beach). In total, we retrieved 79 empty shells, nine unhatched (90% hatching success rate, 87% emergence success).

REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives

Monthly Progress

At Kuda Huraa during May, we monitored and mapped a total of 363 existing frames, and transplanted five new frames around the island.

At Landaa this month, we transplanted 27 new coral frames, kindly sponsored by guests (nine) and the Resort (18), which in total added ~1200 coral fragments onto the reef. In addition, we monitored (cleaned, repaired, photographed) a total of 487 coral frames around the island. We have also been lifting 65 buried frames out of the seabed sand along the Coral Trail, and recycling ~600 fragments.

One of our longer-term goals for 2023 is to restore the ~300 degraded coral frames at our Parrot Reef site, where some frames had been flipped by unusually strong waves. Our aim is to relocate all the frames to a more sheltered side of the reef, re-tag and re-map the frames in QGIS, recycle fragments on all frames, and monitor the site once more. This month, we started to relocate frames into neat lines at the new site, and over four days we successfully moved a total of 135 frames. Special thanks to our Dive Team colleagues and our apprentices (Eegan and Mode) for all their hard efforts.

Coral Bleaching Study

With the sunny warm weather throughout much of May, we observed paling and bleaching of many Acropora colonies in the shallow lagoons at Landaa. Some coral frames were moved into shaded areas under the boardwalk and villas, to encourage faster recovery, and monitoring pictures of colonies at both sites were taken for comparison over time.

At Kuda Huraa during May, of the 300 sample coral colonies under study, we observed ~47% coral paling and bleaching, with Acropora muricata the most impacted species.

Baa Atoll Marine Internship 2023

This month, our coral team gave a presentation for the 12 Baa Atoll Marine Internship students that stayed at Landaa Giraavaru. This was followed by a quiz about coral reefs that detailed coral morphology, reproduction, ecosystem services, threats, and the work that Reefscapers is doing to restore coral reefs.

All children then joined us for a practical workshop to collect coral fragments from the House Reef and build a large-sized coral frame.

Kinolhas Coral Propagation Project

On 27 May, in partnership with Kinolhas Council and Four Seasons Resort Landaa Giraavaru, Reefscapers helped to establish a coral propagation project at Kinolhas (Baa Atoll). This full-day event involved educational presentations by The Manta Trust and Reefscapers, and in-water sessions to demonstrate our coral propagation techniques. We were joined throughout the day by Kinolhas council members and 59 students.

After a warm welcome to the island, two students and two council members joined us in the water to help collect a total of 230 coral fragments from the island’s reef. In the afternoon, students and council members built six small coral frames, kindly sponsored by Four Seasons. The frames were out-planted on the Kinolhas reef, and the first set of monitoring pictures were taken.

Special thanks to the Kinolhas council for their hospitality on such a special and well-organised day.

Coral Relocation Project – Pyramids of Huraa

The wider Reefscapers team have been rescuing masses of corals from a large-scale reclamation project currently underway by the Maldives government at Gulhi Falhu industrial zone. During May, many of these rescued coral colonies were transported to Kuda Huraa and retransplanted onto our large bespoke pyramid frames.

Our team spent many hours in the water, transplanting approximately 1500 mature coral colonies, and constructed three large pyramids, in the shallow house reef. A very BIG THANKYOU to our colleagues at Dive, TropicSurf, and Launch for all their invaluable assistance. The pyramids have already proven to be a great success, attracting lots of attention from staff, guests, and marine life!

This is the second time Kuda Huraa has received corals from this location; the first time being in March 2022, when approximately 10,000 colonies were relocated around the island.

Read our Reefscapers Diaries for further details and photographs of our ongoing coral propagation efforts and reef regeneration experiments, both in the Lab and out in the lagoon, updated each month.