Turtle ID Project
Resort guests and marine biologists have been submitting their turtle photographs to us for identification purposes. During April, we had over 50 submissions to the turtle ID programme, giving new individual sightings for 14 Hawksbills and 5 Green turtles, as well as 28 additional good quality re-sightings of existing turtles in our database.
If you have any photos to share, you can send them to us via our Facebook group … see you there !
Hawksbill turtle EI0447 ‘Hana’
Green Turtle CM159, newly identified
Stevie’s Satellite Tag
Stevie our large adult female Olive Ridley turtle (25.6kg/62.0cm) was found near Six Senses (Laamu Atoll), entangled in a ghost fishing net. She was sent to us on 8 February 2018 suffering from superficial injuries, and was actively swimming and diving on her second day at our Centre.
We released Stevie back into the ocean equipped with a satellite-tracking device – see Stevie’s page for more details, photos and video, and see the interactive map of her journey.
Green Sea Turtle Nests at Landaa Giraavaru
Nest #1 (21 January) – laid too close to the sea, so we relocated it; failed to hatch.
Nest #2 (5 February) – on 2 April, we found 43 hatchlings on the beach, making their way to the sea. Two of the weakest were sent to Kuda Huraa, although ‘Nicolai’ (CM.142) had been attacked by a crab after emerging from the nest and subsequently died from his injuries. A few days later, 3 more hatchlings emerged, so we waited several further days before excavating the nest to find 97 successfully hatched eggshells, plus 10 ‘stillborn’ unhatched eggs and 2 further hatchlings, alive and lucky (that we sent to Kuda Huraa).
Nest #3 (15 February) – relocated all 111 eggs. Expected to hatch 11-16 April, so we excavated the nest on 20th to discover the eggs were still not fully developed. Perhaps the eggs are taking longer than expected because of their relocation.
The protective cage remained on the nest and we continued to monitor. The nest was dug up again on 4 May and 15 May, but most of the eggs were found to consist of only a yolk or an early developmental embryo.
Nest #4 (27 February) – hatchlings emerged on the night of 22 April, managing to successfully dig under the protective cage and make their way into the ocean. 7 hatchlings were found on land, weak and disoriented, and when we excavated the remains of the nest, we found 120 empty eggshells, 2 undeveloped eggs, 2 stillborn eggs and one living hatchling. All 8 hatchlings were sent to Kuda Huraa by seaplane, although one died a few days later.
Nest #5 (11 March) – hatched a day earlier than expected, late morning on 5 May. The weather was very cloudy and rainy, and the hatchlings must have thought it was night time! The 76 hatchlings were scooped up and successfully released the next day, outside the atoll to be safe from predators on the beach (crabs, seabirds) and on the reef (reef fish).
One more hatchling was found when the sand softened, and was sent to Kuda Huraa the next day (7 May). There were still eggs remaining in the nest, most of them being yellow/brownish in colour and undeveloped.
Nest #6 (24 March) – 77 hatchlings emerged on 19 May, and we released them at night from the staff beach. There are still some eggs in the nest that have not yet hatched, so we are monitoring regularly.
Some eggs remained unhatched in the nest, but movements were noticed inside the eggs. The nest was dug up on 22 May, and 79 egg cases were found, 77 of which were shells from released turtles, 3 dead hatchlings (2 eaten by crabs). 30 undeveloped eggs didn’t hatch, and one unhatched developed egg was placed in a sand bucket to ‘incubate’ for a longer time.
Dolphin Cruises and Cetacean ID Project
Our dolphin cruises are a popular guest excursion that also allow us to gather important data on cetacean species. During April, we sighted an estimated 1800 individual dolphins around Kuda Huraa and Landaa Giraavaru, approximately 85% Spinners (Stenella longirostri) and 15% Bottlenoses (Tursiops truncatus). Spinner dolphin pods ranged between 10 – 200 individuals in size, and Bottlenose pods between 4 – 80 individuals. Playful interactions with our boat were common, and calves were usually seen as part of the Spinner pods. Encounters lasted between 1 and 60 minutes long, averaging 20 to 28 minutes. We were also lucky to occasionally encounter False Killer Whales (Pseudorca crassidens) and Short-finned Pilot Whales (Globiocephala macrorhynchus).
We have set up databases in our DARWIN software to record the sightings for each of the 4 commonly sighted cetacean species. When conditions are suitable, we take dolphin photos to use for identification purposes. Only high-quality photos (angle, sharpness, clarity, lighting) are used for identification. Any low-quality images of fins with significant markings are kept for future reference.
During April, a total of 22 spinners, 2 bottlenose and 7 false killer whales were added to the database. Two re-sightings of spinner dolphins have been confirmed; SL003 and SL004 were both recorded together on 17 and 22 April, suggesting the same pod was observed on both occasions.
Life in our Fish Lab
We dedicated this month to breeding Clark’s Clownfish with our updated protocol. We focused our efforts on the four best techniques, and successfully produced 313 juveniles (with a good survival rate of 22%). If we can maintain this level of production, we could start to sell our fish under an ‘ecolabel’ (as our attempts at releasing in the wild have been poor). This would help reduce the pressures on wild fish taken from reefs for marine aquaria.
One of the most important improvements to our protocol has been to increase the quality of foods given to our breeding pairs, by introducing rotifers enriched with microalgae/S-presso, and feeding 4 times per day. We also change 70% of the water volume daily, and continue to feed the larvae 3 times per day.
Wild Reef Anemone Monitoring Programme
The aim of this project is to increase our knowledge of wild sea anemones and their clownfish populations, 2 years after the global bleaching event of 2016 that affected the Maldives.
Whilst based on the Four Seasons Explorer for one week, Carla (our intrepid aquaculture specialist) visited 11 dive sites and catalogued an impressive 143 individual anemones. 94% of the specimens were in good health, and some reefs had an incredible density of anemones of more than 20 individuals per square metre!
Reefscapers Coral Propagation
See our monthly Reefscapers Diary for all the latest photos and coral updates from our specialist coral biologists based at the Marine Discovery Centres at Landaa Giraavaru and Kuda Huraa.