Fish Lab & Aquaria – Marine Life in the Maldives

nudibranch Jorunna rubescens mating, egg ribbon

Nudibranchs are hermaphrodites – Jorunna rubescens fertilise each other ✨ And an egg ribbon attached to one of our coral frames

During October, we saw an increase in spawning from our anemonefish breeding pairs, a reduction in jellyfish numbers, and a steady population of our Fish Lab specimens.

Large Aquarium

The resident corals continue grow, however, one frame and a section of Acropora has bleached and died so we plan to replace this with ‘massive’ coral species with greater resilience.

We observed a small crab eating a resident fish, so we plan to replace some of our residents with larger species (the crabs have proved impossible to catch!)

Plankton Production

  • Plankton – good, steady production levels.
  • Algae – continuing steadily on a four-day turnover, and providing ample food for artemia grow-outs.
  • Artemia – some population variations, but sticking with the nanno3600 formula has improved things.
Zooplankton monitoring and ID - Porcelain crab larvae (Maldives)

A porcelain crab larva, photographed as part of our new project on zooplankton ID and monitoring.

Aquarium One

This month, Aquarium-1 has been experiencing issues with the water inflow system that we have so far been unable to identify and fix.

  • Mini coral frame – healthy overall; several dead fragments were replaced with Heliopora coerulea and Acropora
  • Maldivian clownfish (Amphiprion nigripes) – newly introduced, continues to grow and adapt successfully.
  • Sailfin tang (Zebrasoma desjardinii) – a cut across the dorsal fin was likely caused by a fish or a crab.
  • Peackock mantis shrimp (Odontodactylus scyllarus) – growing rapidly.
  • Sea star (Linckia multifora) – healthy, with variation in arm length.

Aquarium Two

  • Clark´s anemonefish (Amphiprion clarkii) breeding pair – laid two batches of eggs this month.
  • Mini coral frame – good health and corallite growth. The new fragments (September-October) continue to acclimatise.
  • Sea star (Linckia multifora) – was slowly recovering after a period of ill-health, but this month was found injured and missing one arm (attacked by an unknown resident?). It is now recovering in quarantine, where it has started to eat and move normally.
Aquarium-1 mantis shrimp
Aquarium-1: mantis shrimp
Aquarium-1 injured Sailfin tang
Aquarium-1: injured Sailfin tang
Strobilation is defined as asexual reproduction by transverse division of the body segments which develop into separate individuals.

Jellyfish – Aurelia aurita

After some initial problems, the jellyfish sump is now working very well for each of our Kreisel tanks. Some jellies were lost, but now the population has stabilised, and the water quality is consistently good. We are now performing a 35% water change every two days (using the new 35L sump water, acclimatised to room temperature).

The Four Seasons Resorts Maldives Apprenticeship Program is dedicated to providing enthusiastic Maldivians with the expertise required to excel as professionals in the hospitality industry. Young men and women (aged 17 to 20) are invited to apply to the annual intake of this government-accredited Technical & Vocational Education & Training (TVET) program.

Since the program’s inception in 2001, the total number of graduates stands at 651, making it one of the most successful tourism & hospitality apprenticeships in the Indian Ocean region. For further information, read about the 2021 inauguration and join the Official Facebook Community.

Core program goals: develop technical skills and professional knowledge; coach mindsets, attitudes, values, and behaviours.

Whilst living, studying and working onsite at Kuda Huraa and Landaa Giraavaru, apprentices gain hands-on experience in:
– Food & Beverage Prep/Service; Housekeeping & Guest Services;
– PADI Dive Master; Water Sports; Marine Biology;
– New modules in 2021: Safe Maritime Transport & Boat Mechanic, and Front Office & Recreation Attendant.

Marine Biology internship Maldives Jinan

Jinan, a current apprentice, harvesting coral fragments from our frames, for retransplantation

REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives

'Bundling' observed in Acropora secale Reefscapers Maldives

Coral spawning: ‘Bundling’ of gametes observed in Acropora secale (October 2021)

Monthly Progress

During October, we transplanted 27 new sponsored coral frames around both resorts, using ~2,000 harvested coral fragments for our transplanting and maintenance work.

Coral Spawning Event, October 2021

An initial sign that coral colonies are ready to spawn is the presence of gametes within the coral tissue, that look like tiny white eggs initially, which then grow in size and develop colouration (pink/orange).
On 19 October at Landaa Giraavru, we first spotted eggs within various Acropora species of corals.
26 October – A synchronised spawning event took place at 19:57, involving many coral species, and lasting 20 to 30 minutes. The gamete bundles float to the surface and we were able to collect them using custom-made egg collection devices.

On 27 October at Kuda Huraa, we observed coral spawning occurring from 20:00 to 20:15 (Maldives time, GMT+5). We successfully harvested some eggs, and placed them into our aquarium for observation, along with a dead coral skeleton as a settlement substrate. Some eggs became attached by 20:45 (30 mins after spawning) but we did not see coral larvae.
From our notes, we observed this spawning event occurred:
– 1.5 hours before the lowest tide (which was at 21:42);
– Seven days after the full moon (which was on 20 October);
– One day later than in Landaa Giraavaru (Baa Atoll).

Reefscapers coral spawn collection Maldives
Reefscapers coral spawn collection devices Maldives

Coral Spawning Workshop

This month, we took part in the second series of a two-day online coral larvae workshop in partnership with CSIRO, the MMRI and MUI (among others) to further understand and identify coral spawning events across the Maldives. This informative workshop detailed the use of coral larvae in reef restoration, to upscale future efforts. It is evident that sexual propagation will result in higher genetic diversity amongst species in comparison to asexual propagation. Moreover, corals are extremely fecund, meaning a large number of juvenile corals could be produced if mortality at early life stages of fertilisation and settlement are reduced. This technique could enhance coral propagation programs here in the Maldives, if the asexual technique is coupled with sexual broadcast spawning and rearing.

At Marine Savers, we have transplanted and grown many different species of corals over the years which are large enough to produce mature spawning colonies. Our large database allows us to pinpoint transplantation dates, identify age of maturity, track mature colonies, and record coral spawning across multiple years. This data can be used to ensure genetic diversity, as we can confirm gamete collections from different frames based on these dates.

To expand our knowledge of coral spawning around Landaa Giraavaru, we reviewed the data from our previously documented spawning events (2013 – 2020). It is incredibly difficult to predict when coral might spawn, therefore it is important to take note of tidal cycles, lunar cycles, and water temperatures from previous years, to be utilised as indicators for predicting spawning this year.

Check out our Reefscapers 2021 Diary for further details and photographs of our ongoing coral propagation efforts and reef regeneration experiments, both in the Lab and out in the lagoon. This month, we have more details, photos and video of the coral spawning event.
Reefscapers coral spawn Maldives

Coral spawning: we harvested coral spawn directly from our coral frames, and photographed it back in our Fish Lab (October 2021)

Sea Turtle Rescue & Conservation

Ari stranded Olive Ridley turtle amputee Maldives

Ari (a female Olive Ridley) was found entangled in a ghost fishing net, and was admitted to our sea turtle rescue centre on 13 October

Sea Turtle Rehabilitation

At the close of October, we were caring for 3 Olive Ridley turtles (Lepidochelys olivacea) and 1 Hawksbill (Eretmochelys imbricata) in our Rehabilitation Centre at Landaa. At Kuda Huraa, our turtle patients include 2 rescued Olive Ridleys, plus our rehabilitating juveniles: 4 Green turtles (Chelonia mydas) and 2 Hawksbills.

Flying Turtles

During October, we finalised details with our overseas partners to send our unreleasable Olive Ridley patient, ‘April’ to a new permanent aquarium home, with departure planned for 19 November. Ale, our turtle expert and Marine Discovery Centre Manager, will be accompanying April on her journey, along with staff from the aquarium.

Maldivian Sea Turtle Identification Program

During October, we received 6 submissions of photo sets from the public to our Sea Turtle ID project. Our current database catalogues 5,140+ photographic sightings, and to date has positively identified and named a total of: 1315 Hawksbills, 276 Greens and 98 Olive Ridleys.

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

Turtle ID Maldives photo submissions Hawksbill male
Junior Marine Savers activities

Further News & Updates

You might also be interested in:
– our Dolphin ID Project,
– our unique Sea Turtle Lagoon Enclosure, and
– our Zooplankton Monitoring Project (new in 2021). 

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 view your sponsored frame photographs (updated every 6 months) as part of our Maldives resorts Coral Frame Collection.

‘Junior Marine Savers’ photos: (1) Transplanting a Reefscapers coral frame; (2) feeding turtle hatchlings.

Junior Marine Savers activities

Our Unreleasable Turtle Residents

Our Current Turtle Patients

Our Juvenile Turtle Patients

Inguz juvenile Hawksbill turtle Maldives
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