Charlie observing the behaviours of our injured amputee turtles
Tina cleaning algae from a turtle carapace using dilute iodine solution
Fish Lab & Aquaria – Marine Life in the Maldives
The Main Aquarium
This month, we collected some new specimens for our large display aquarium, including:
- orange spotted blenny (Blenniella chrysospilos)
- two chestnut eyelash blennies (Cirripectes castaneus)
- two six-spot sleeper gobies (Valenciennea sexguttata)
We have also deep-cleaned, redesigned, and landscaped half of our breeding tanks, and welcomed four new species to the Fish Lab.
- Tank #21: blue yellow damselfish (Chrysiptera parasema)
- Tank #22: humbug damselfish (Dascyllus aruanus)
- Tank #31: saddled toby pufferfish (Canthigaster valentini) – particularly interesting as different pufferfish species use different nest substrates and laying methods
- Tank #35: bicolour blenny (Ecsenius bicolor)
humbug damselfish (Dascyllus aruanus)
Some of the breeding tanks in our dedicated Fish Lab
- Algae – consistently cycling at full volume
- Artemia – production is keeping up with the demand of the main tank at 5g of cysts a day, with one 100L algae tub containing nauplii for grow-out
- Rotifer – volume experienced a slight drop this month, due to a procedural error, but the culture now remains stable at 330/ml
Jellyfish – Aurelia aurita
All jellyfish in the large Kreisel cylinder continue to thrive with no signs of damage or shrinking. The water quality is also very good after the introduction of the UV steriliser.
Our new juvenile ephyra sea nettle jellies (Chrysaora fuscescens) continue to slowly develop in our rearing Kreisel tank, although we continue trying to find the ideal environmental conditions.
Zooplankton Survey Study
Our Zooplankton Survey is on hold until after the tourist high season.
On 24 March, our apprentice found a shrimp female (unknown species) with eggs, that appeared to be malnourished. She was transferred to our Fish Lab and fed and cared for, with a view to collecting the larvae for rearing. On 27 March, the eggs hatched successfully, revealing the female’s blue legs and carapace patterning, characteristic of a young (150 day) female carpet shrimp (Saron marmaratus).
A nobbed sea slug (Phyllidia varicosa)
Spotted porcelain crab (Neopetrolisthes maculatus)
Very Cosy Nudibranch
This month at Kuda Huraa, the nobbed sea slug nudibranch (Phyllidia varicosa) has been a common sight grazing around our House Reef coral frames. They are a possible hazard to our coral polyps, but potentially useful as they also feed on hydroids, sponges and other outcompeting organisms that might pose a threat to the health of the corals.
Megafauna and Marine Life
At Landaa this month, our ever-popular ‘Marine Discovery Immersion Tour’ was enjoyed by a total of 70 visitors, across 16 tours, averaging 25 minutes duration. In addition, a total of 143 guests joined 27 outdoor excursions, with the most popular being the Dolphin Cruise and Turtle Safari guided snorkel trip.
- Women in Science Day – we celebrated our talented marine team
- Dive Against Debris – we joined our colleagues from the Dive and the Recreation departments for a special reef clean up, collecting a total of 22kg of marine debris (data submitted to PADI AWARE – DAD)
Saddled toby pufferfish (Canthigaster valentini)
Female carpet shrimp (Saron marmaratus)
Camel shrimp (male)
Ornamental Shrimp Breeding
We have scaled back our fish-breeding to expand our more successful research on shrimp-breeding. Our focus is to produce replicable and consistent data for our research paper on Thor amboinensis, and to continue tracking and describing the reproductive cycle of Lysmata amboinensis.
- Sexy shrimp (Thor amboinensis) – Research continues for publication, with a total of 11 clutches successfully collected since the start of the project, all with credible data.
We had three new clutches in March, yielding 869 larvae that are healthy and growing well, with minimal mortality in these early stages. The 27 previous clutches continue to settle and grow, with the earliest larvae reaching “semi-mature” juvenile stage. Our newly developed rearing protocol is proving to be very effective, returning a consistent survival to settlement rate of 30-40%.
A total of five shrimp from the December clutches have matured, transitioned to females, and are now carrying egg clutches to produce our first batch of second-generation embryos/larvae. This validates our breeding protocols, and excitingly, opens new research pathways into multi-generational breeding.
- Boxer shrimp (Stenopus hispidus) – We continue to record our observations on ovary development and reproductive cycle (three clutches produced this month).
- Camel shrimp (Rhynchocinetes durbanensis) – seven clutches produced this month, from our three breeding females.
- Skunk cleaner shrimp (Lysmata amboinensis) – During March, we finished the data collection for our research paper, and have started to organise and analyse the data.
- Mantis shrimp (Odontodactylus scyllarus) – Now a sufficient size to determine gender, we have realised that despite being named after a Roman goddess, Juno is actually a male… but the name has stuck! Following the remodel and tank move, Juno has been more active, and has found a new favourite spot to sit and watch the world. He has used his powerful clubs to smash a large hole in an inverted flowerpot, and he likes to sit upright in the hole.
Sexy shrimp (T. amboinensis adult female)
Our resident mantis shrimp JUNO at home in his plant pot
Maldives Sea Turtle Rescue & Rehabilitation
Bethany measuring and weighing our recovering turtles
Tina keeps our turtle pools sparkling clean!
At the close of March, 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.
This month, we inspected and maintained our large turtle enclosure out in the lagoon, and repaired several small holes that had developed in the netting.
At Kuda Huraa, we were at capacity with five Olive Ridley rescue patients occupying our rehabilitation pools. This month, the dividing wall between pools 3 & 4 was removed, and the whole tank was repainted. (Many thanks to our colleagues in Engineering, for their quiet handiwork that minimised disturbance to the turtles.)
Our long-term turtle patient, Ari has been very lucky this month, as a returning guest has gifted her a generous donation and some delicious octopus! Unfortunately, she did not like the octopus, but it was soon shared between the other turtles. Ari is now the proud resident of our newly elongated pool, and she is actively making the most of the extra swimming space.
Good news about Emma this month, as she started to rest on the bottom of her tank for the first time! When we introduced her to the shared pool with Michelangela, she was soon able to dive down for food with ease, and rest on the bottom in her new ‘crate cave’.
Alex checks our turtle pool divider
Shona feeding a ‘fish popsicle’ as part of our environmental enrichment work for captive sea turtles
Updates on Our January Admissions
- Xanchi – is making good progress as his wounds heal, but his injured flipper is still not functioning properly. His buoyancy is not an issue, so in the coming weeks we will transfer him to our ocean enclosure out in Landaa’s lagoon, in readiness for release.
- Seakid – is now very enthusiastic during feeding, and tries hard to overcome his buoyancy issues to dive down for food.
- Michelangela – her wounds have completely healed, and she continues to impress with her diving skills. She will soon be ready for release back into the big blue!
- Burrita – is doing well with her buoyancy training, and she can now reach the bottom of the pool to feed
Sea Turtle Nest Protection
On 10 and 20 March, we had two further green turtle nests laid on the beaches at Landaa. They are close to nests #1 and #2 (near villa 200). A third turtle made a false crawl in the same area on the night of 20 March, without laying a nest.
- Nest #1 – from 8 March, we started actively monitoring to catch the emergence of the first hatchlings. No activity was seen on the expected hatching date (day #60) and after a further 10 days we decided to excavate the nest. As expected, there were no fully developed eggs, with only 14 out of 106 eggs containing visible embryos. We suspect this was due to flooding, as recent tides have been higher than average, and the egg chamber itself was only 90cm deep. The egg shells were pale and translucent (rather than a solid white colour) and the yolks were watery.
- Nest #2 – is close by, and there is no activity so far. Sadly, we are anticipating a similar result.
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.
Maldivian Sea Turtle Identification Program
During March, from the 22 new photo sets submitted by the public this month, we were able to add 6 new individuals to our national turtle database, and confirmed resightings of 5 named turtle already in our database.
Our current database now has uniquely identified totals of:
1411 Hawksbills, 305 Greens and 97 Olive Ridleys (from 5500+ separate sightings, across 17 different atolls of the Maldives).
Submissions consist of close-up photographs of the turtle facial profile, enabling us to outline the unique pattern of scales (scutes) that act like a human fingerprint.
Spotted a turtle? Share your photos
REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives
At Landaa during March, we transplanted 32 new coral frames, kindly sponsored by guests (17), the Resort (13), and online orders (2), using a total of ~1200 new coral fragments. In addition, we monitored (cleaned, repaired, photographed) 646 coral frames at various sites around Landaa Giraavaru. This month, we have also been recycling and lifting coral frames around Landaa, including 12 coral frames buried in the sand at the Turtle and Blue Hole sites, and recycling 290 coral fragments at the Turtle and Bissie’s Reef.
At Kuda Huraa, we transplanted 6 new guest coral frames, kindly sponsored by guests (4) and the Resort (2). We also monitored a total of 235 existing frames (mainly at the House Reef site), retagged 23 frames, retransplanted 27 frames (House Reef and Channel sites), and remapped 73 heart-formations (Deep House Reef site).
Coral Bleaching Monitoring
From late March to late May, we experience higher than average ocean temperatures in the Maldives due to the transition from the NE to the SW monsoons that brings calm periods with little wind and rain. Warmer ocean currents coupled with zero cloud cover can be extremely stressful for shallow water corals, resulting in paling and fluorescence, followed by possible bleaching and eventual mortality.
We have deployed our temperature loggers at various sites in the lagoons to record hourly SST (sea surface temperature). We will be monitoring the severity of any coral bleaching, to determine which species demonstrate the greatest resilience and which locations offer the best protection.
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.
Further News & Updates
You might also be interested in:
– our ongoing Dolphin ID Project, our specialised Sea Turtle Lagoon Enclosure, and our Zooplankton Monitoring Project.
Looking for details of our Reefscapers coral propagation and reef restoration program ? Then head over to our Reefscapers Diaries for all the latest updates.
You can sponsor your own frame and see photographs (updated every 6 months) in our Coral Frame Collection.
Junior Marine Savers activities: (1) Reefscapers corals, (2) turtle care.