Marine life on reef

Fish Lab & Aquaria – Marine Life in the Maldives

The wavemakers in our large display aquarium were removed and deep cleaned this month, to remove the build-up of CCA and algae. We also replaced the rotor blades, and adjusted the positioning to improve water flow efficiency.

Plankton Production

  • Algae – consistently cycling, with just a slight drop in volume
  • Artemia – production is keeping up with the demand of the main tank at 4g of cysts a day
  • Rotifers – volume dropped dramatically, as one of the buckets suffered a complete failure (likely due to bacterial growth on the bucket base). The remaining bucket volume was split, and the population is recovering
  • Copepods – on 11 July, we established our very first a copepod culture, which is running well.

Jellyfish – Aurelia aurita

This month, we deep-cleaned our large display Kreisel cylinder. All mature jellyfish continue to thrive, with no signs of damage or shrinkage. The UV light, chiller and filter all continue to function well, and together create good water quality. Our small Kreisel jellyfish are growing nicely, and should be moved to the 100L Kreisel and semi-open system in the next few weeks.

Seaweed Mariculture – edible sea lettuce (Ulva lactuca)

We are making progress with our experiments into seaweed mariculture (marine farming). In an attempt to enhance growth, we have started nutrient-dosing, and also using a blue light system.

Dolphin spotting Maldives

Read about our Dolphin ID project, and learn how a dolphin’s fin shape can help us uniquely identify them!

Megafauna and Marine Life in the Maldives

At Landaa, our Marine Discovery Immersion Tour was enjoyed by 136 visitors during July, and a total of 525 guests joined 44 excursions guided by our team members.

At Kuda Huraa, 256 guests enjoyed our guided marine excursions, including the Dolphin Cruise and numerous adventure snorkel trips.
Sightings of hawksbill sea turtles (Eretmochelys imbricata) remain low, maybe due to the current rainy season (SW monsoon), but also the populations may have shifted to new local grazing areas in search of better quantity and quality of foods, following the recent national coral bleaching. We have also observed that the hawksbills we are seeing have missing central and marginal scutes, which could be an indication of poor health.

This month has seen good numbers of blacktip reef sharks (Carcharhinus melanopterus), as well as regular sightings of bottlenose wedgefish (Rhynchobatus australiae) and young Napoleon wrasse (Cheilinus undulatus).

Marine biologists Maldives commute

Our Kuda Huraa team’s morning commute

Fish Lab shrimp breeding Maldives

Shrimp breeding in our Fish Lab at Landaa Giraavaru

Ornamental Fish & Shrimp Breeding

Ornamental Shrimp Breeding

  • Sexy shrimp (Thor amboinensis) – The F1 larval generation from June are settling (not fully metamorphosed). The second F2 generation from June has resulted in a further seven settled larvae. Our settled F2 juveniles are fully settled in the display tank, visible to guests and separated from the previous two generations (F0 and F1). They are growing nicely, and we expect to see our first protandric sex change in the next few weeks as they reach 70 days old. On 27 July, a new F1 generation hatched, producing 289 larvae.
  • Boxer shrimp (Stenopus hispidus) – monitoring.
  • Camel shrimp (Rhynchocinetes durbanensis) – on 29 July, we successfully collected one larval clutch that is growing well so far.
  • Skunk cleaner shrimp (Lysmata amboinensis) – on 21 July, we successfully collected one larval clutch but it succumbed to die-off the following week.
  • Marbled shrimp (Saron marmoratus)monitoring continues.

Ornamental Fish Breeding

  • The two surviving Clark’s clownfish larvae have now metamorphosised and are growing nicely as juvenile fish. They will soon be moved into the display tank when they are large enough.
  • We collected a clutch of eggs from the blue damelfish (Pomacentrus pavo) that we spotted on the wavemaker. After five days, 15 larvae hatched, but our new copepod food culture was slow to establish, so we now have four larvae remaining.
  • We have a new pair of saddled toby pufferfish. ‘Sif’ and ‘Loki’ have acclimatised well and have already spawned into the water column (eggs were presumed lost via the outflow). We have been closely monitoring their nesting behaviours, and we are optimistic for future spawning events.
  • Fish production has started using the large new tanks, focusing on the cardinalfish. As a mouth-brooding (oral incubator) species, they typically produce larger fry that should be easier to maintain. Currently, the school is settling into the tank and eating well.
Fish Lab Pomacentrus pavo larvae 0-2 days

Pomacentrus pavo larvae (0-2 days)

Fish Lab Pomacentrus pavo larvae 0-2 days

Pomacentrus pavo larvae (0-2 days)

Fish Lab Pomacentrus pavo larvae 4 days

Pomacentrus pavo larvae (4 days)

Maldives Sea Turtle Rescue & Rehabilitation

MAW feeding time Olive Ridley turtle Maldives

Feeding time for Olive Ridley turtle patient MAW

Hawksbill turtle swimming over healthy reef Maldives (Thais)

Hawksbill turtle swimming over a healthy coral reef, Maldives

Monthly Updates

At the close of July, we were caring for 4 Olive Ridleys (Lepidochelys olivacea), 1 Hawksbill (Eretmochelys imbricata), and zero Green sea turtles (Chelonia mydas) in our Rehabilitation Centre at Landaa – see Our Current Turtle Patients.

On 4 July, Kuda Huraa welcomed the return of Maw, who was transferred back from Landaa. She loves feeding time, and swimming around the pool with her enrichment toys. She still presents with buoyancy syndrome, so we have started to take her for ocean swims at low tide. She had some difficulties at first, but soon got the hang things.

Ocean Enclosure

Several stormy days during July have damaged our large outdoor turtle enclosure at Landaa, which is exposed to wind and choppy seas out in the lagoon. The shading covers were damaged, so we removed them and have ordered some replacements.

Maldivian Sea Turtle Identification Program

During July, from the six new photo sets submitted by the public this month, we were able to add zero new individuals to our national turtle database, and confirmed resightings of zero named turtles already in our database.

Our current database now has uniquely identified totals of:
1437 Hawksbills, 303 Greens and 97 Olive Ridleys (from 5400+ 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

Turtle ID Maldives - unique facial scales

REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives

Reefscapers oral frames artificial reef Maldives
Reefscapers coral frames flat

Monthly Progress

At Kuda Huraa during July, we transplanted five new frames, monitored 143 frames, and retagged 25 frames. In addition, our team has been very busy relocating 120 Water Villas frames  (lifting some from the sand, moving others back into full sun now the seasonal bleaching risk has past) and creating a new coral trail of 250 frames to guide snorkellers around our reef. At the Channel site, we have been replacing dead corals, relocating frames to areas of higher water flow, and cleaning 250 old frames for recycling.

At Landaa this month, we transplanted 32 coral frames, kindly sponsored by guests (11), online (one), and the Resort (20), adding a total of 1685 coral fragments to the reef. In addition, we monitored (cleaned, repaired, photographed) a total of 351 coral frames at various sites around Landaa Giraavaru. We also lifted 25 buried frames out of the seasonally shifting sands, and added 450 new fragments where necessary, to any degraded lower bars.

Coral bleaching recovery Maldives

On our Reefscapers coral frames and the natural reefs, we are seeing the recovery of paled corals, following the period of seasonally high ocean temperatures. Corals regain their colouration as they take-up symbiotic algae.

NOAA Bleaching Warnings

The increased cloud and rain experienced in July have reduced the seasonal water temperatures, and NOAA’s Coral Reef Watch forecasts “No stress” levels. Many paled and stressed coral colonies, both on our frames and out on the reefs, have seen a relatively quick recovery this year.

Reefscapers Coral Research Experiments

  • We have restarted our coral micro-fragmentation work with two species of ‘massive’ corals. We want to see how successfully the coral fragments attach to the tiles and grow, before expanding the scope in future months.
  • We have extended our research into methods of attaching coral fragments onto our Reefscapers frames. We want to see if the coral fragments will encrust and grow successfully onto the frame.
  • Our intern, Sol, has been taking photo-transects to assess coral cover and diversity on various reefs around Landaa Giraavaru, and we have compiled a catalogue of coral species.
Reefscapers coral cover survey Maldives
Reefscapers coral cover survey Maldives
Junior Marine Savers activities

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.

Junior Marine Savers children turtle care Maldives