Maldives Sea Turtle Rescue & Rehabilitation

At the close of April, we were caring for 3 Olive Ridleys (Lepidochelys olivacea), 1 Hawksbill (Eretmochelys imbricata), and zero Green sea turtles (Chelonia mydas) in our Rehabilitation Centre at Landaa.

At Kuda Huraa, ‘Image-J’ analysis has been used to determine the levels of buoyancy in our patients Burrita and Seakid. Initial results analysing above-water surface areas of the carapaces suggests that over the course of the month, both turtles showed a significant improvement (reduced surface areas, as the turtles now sit lower in the water).

Our long-term turtle patient, Ari has been fussy with her food this month, and is now refusing to eat both squid and prawns. She is visibly low on energy, and has been interacting less with visiting guests. We will be giving her more swims out in the lagoon, and will introduce more environmental enrichment toys.

Meanwhile, Emma has made great progress with her diving, and is now often found on the bottom of her tank. She loves resting in her crate-cave with her head sticking out, much to the amusement of guests. Usage of her left flipper has been increasing, and she is now able to successfully hunt live crabs, so hopefully she will soon be fit for release.

Ocean pen

This month, we inspected and maintained our large turtle enclosure out in the lagoon, removing coral growth and marine organisms, and repairing several small holes that had developed in the netting.

Updates on Our January Admissions

• Xanchi – most wounds have now healed, and his fore-flipper laceration is healing well, but it is swollen and he is not yet using it. We have started a course of antibiotics that we hope will reduce the swelling; once Dr Kat gives the all-clear, Xanchi will spend a short period in our ocean enclosure prior to release.
• Seakid – moved to a bigger tank, and he can now reach the bottom to feed, however, he still floats back to the surface. As soon as he can rest on the bottom, he should be ready for release.
• Burrita – is making good progress with her diving and can reach the bottom of her tank for food, however, she has restricted movement in her right front flipper. She continues to have high energy levels and is a favourite with guests as she likes to splash everyone during her feeding time!
• Michelangela – was successfully released on 4 April after 75 days of TLC at our Centre, and a healthy weight gain of 1.9kg. She was released on a Dolphin Cruise out in the open ocean, and waved on her journey by 20 enthusiastic guests. Two days earlier, Michelangela had been fitted with a satellite tag that had been secured and tested, but unfortunately the signal was lost shortly after release. She travelled 1500m to a final known location close to the island of Girifushi. We think the tag may have malfunctioned or fallen off.

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 #2 (laid 27 January) – we waited for eight days after the predicted hatching date, but after no visible activity we decided to excavate on 4 April. Unfortunately, out of 81 eggs laid, only one showed significant signs of development, likely because of flooding by the high tide.
• Nest #3 – the hatchlings emerged right on schedule on 6 April (exactly two months after laying). Afterwards, we excavated the empty nest as standard procedure, to happily discover a hatching success rate of 94% out of 96 eggs.
  – Three hatchlings were discovered alive inside the nest and were released
  – Three hatchlings were found dead in the nest
  – Six unsuccessful eggs.
  The top of the 10cm deep egg chamber was at a good depth of 72cm below the surface, and the location near tree roots would have increased water drainage.
• Nest #4 – surprised us all by not only hatching at midday, but also after just 56 days (on 14 April). The subsequent excavation revealed two live hatchlings at the bottom of the nest, which were released to give a hatching success rate of 89% (97 hatchlings out of 109 eggs laid). The remaining eggs were either completely undeveloped, or contained underdeveloped/malformed embryos.
• Nests #5 & #6 – expected to hatch during May, so we have deployed our remote monitoring camera, and we will soon start nightly in-person checks.

REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives

Monthly Progress

At Landaa during March, we transplanted 38 new coral frames, kindly sponsored by guests (23), the Resort (12), and online orders (3), using a total of ~2100 new coral fragments. In addition, we monitored (cleaned, repaired, photographed) a total of 600 coral frames at various sites around Landaa Giraavaru. We have also lifted a total of 78 buried frames out of the sand at various sites, and repopulated with new fragments where necessary.

To celebrate Earth Day (22 April) the Resort sponsored a commemorative coral frame, which was built by guests and staff. A big thank you to everyone who came to participate and support the event. 🙏

At Kuda Huraa, we transplanted 7 new guest coral frames, kindly sponsored by guests (2), the Resort (2), and online orders (3). We also monitored (and mapped) a total of 182 existing frames (mainly at the House Reef site). In addition, we relocated 108 frames at the Water Villas site to provide the coral with shading and reduce stresses over the warmest period of the year.

Coral Bleaching Study

Here in the Maldives, we are currently in the high ocean temperature season (March to May), so our team is actively monitoring for signs of coral stress, paling and coral bleaching. Our bi-weekly surveys of five sites around Kuda Huraa are monitoring 300 coral colonies (135 coral frames, nine coral species).

This month, we conducted 20 hours of bleaching monitoring (two dives and nine snorkels), and our results so far show 17% colonies are paling and 1% are bleached, with the shallow Water Villas site currently most impacted by the warmer ocean temperatures.

Addu Coral Festival

Members of our team attended the 2023 ‘Coral Festival’ on S. Hithadhoo from 27-30 April (organised by the Maldives Coral Institute). Our Reefscapers stall was visited by global government representatives, NGOs, charities, international conservationists, and many interested members of the public from nearby local islands. It was an ideal platform to showcase the full range of our work to fellow marine biologists and passionate conservationists.

On the second evening, our 2023 coral spawning documentary (embedded below) was screened, alongside videos from the Manta Trust and the recent Nekton deep sea expedition. Throughout, our team attended various lectures, including:

• keynote presentations by prominent coral scientists Prof Callum Roberts and Prof Madeline Van Oppen
• workshops on artificial intelligence in ocean science
• panel discussions on coral restoration and conservation

Monitoring for Coral Gametes and Observing the April Mass Coral Spawning Event

Over several nights at Landaa, we observed multi-specific spawning in 100+ coral colonies (from 8 different species) at various times after sunset, and we successfully collected gametes for ex-situ fertilisation and settlement.

At Kuda Huraa, we conducted 22 hours of coral monitoring across three sites around the island (thanks to our colleagues at Tropicsurf for their valuable assistance 🙏 ). We observed spawning in 130+ coral colonies, and collected data on 139 colonies (9 species).

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.