We breed three species of Clownfish in our Fish Lab at Landaa Giraavaru
Erin's Monthly Marine Musings
Here at Marine Savers, we had barely blinked the salt water out of our eyes, and March was coming to an end! So much has happened every single day this month, that we can hardly remember what life was like before we lived and breathed corals. From a last-minute sea turtle rescue to some epic guest excursions, to spending hours underwater transplanting coral colonies… we may be tired, but we are wired with energy!
Resort guests who visit our Marine Discovery Centre often ask us what it’s really like to be a marine biologist in the Maldives … and the best answer is: this is not simply a career, but a calling. If you’re driven by passion alone, you may eventually grow weary; for genuine success, we are infused with purpose throughout the entire Reefscapers team and Four Seasons Family… making magic happen!
We can choose to experience the world differently – miracles and mystery lie all around us, deep in the ocean and deep within our own spirit. We can venture beyond our five senses and connect to the life and the environment around us. We are truly blessed to call the Indian Ocean our home, and every time we descend onto the house reef, we say a little ‘thank you’. As we rebuild the reefs, focused on the present moment, and fuelled in everything we do, life becomes our playground. We are optimistic that all our new corals will not just survive but thrive in these beautiful waters, expanding the reef genetic pool as well as providing homes for all the special marine creatures.
Fish Lab & Aquaria – Marine Life in the Maldives
Our large 4000L marine aquarium at Landaa is a popular feature with guests and staff alike
Large Aquarium
All our marine residents continue to do well, although there have been some cases of bleaching on the hard corals due to the warmer inflow water (because of the seasonally elevated ocean temperatures).
Plankton Production
Plankton production remains consistently good. Rotifer numbers are maintaining nicely after a slight drop in number at the beginning of the month. Following trials rearing Artemia on a scaled-back algae supply, we are seeing sustainable growth with a 20L bucket (indoors) and a 100L bucket (outdoors), fed part Nanno360 and part Thalassiosira weissflogii.
Zooplankton Survey Study
During March, we restarted our Zooplankton Survey, and have been practising plankton tows out in the lagoon, and processing the samples we have collected.
Jellyfish – Aurelia aurita
The February strobilation resulted in malformed and poorly developed ephyra, so on 21 March we started growing a new batch of polyps (with strobilation expected during April).
Since improving the outflow trap with mesh and silicone, we have now restocked our large display cylinder with a total of 124 jellyfish of various sizes.
Interestingly, we observed a bloom of small jelly-like creatures in one of our breeding tanks this month. Under the microscope, we identified these as Phialella quadrata, likely introduced through the inflow water. Due to their small final size (only 1-2 cm) they were deemed unsuitable for display and released.
Ornamental Fish Breeding
- Common clownfish [Australia] (Amphiprion ocellaris) – the juveniles continue to thrive and are a guest favourite. They are still not hosting on the real anemone, and so we removed the rubber band ‘anemone’ to encourage them. The breeding pair in Tank 11 continue to lay eggs on a semi-regular basis, and has slowed since we stopped the specialised breeding diet.
- Clark’s clownfish (Amphiprion clarkii) – several clutches of eggs were laid during the month. We attempted to allow the parents to rear one clutch with no success as they predated on them. The second clutch was removed and placed in a 2L flask with constant aeration. This worked for the first few days to prevent anoxia, but was ultimately unsuccessful. A final clutch was successfully grown to Day-7, and subsequently hatched on 31 March, producing some viable larvae.
- Maldivian clownfish (Amphiprion nigripes) – the juvenile continues to do well, and has completed the metamorphosis stage with a clear white band and black fins. The breeding pair (main tank) are consistently producing eggs, with a 4-5 day turnover between clutches. Nest clearing activity increases between 09:30-10:00, and has been found to occur 1-5 hours prior to egg laying. Fertilisation of the clutch is completed after approximately two hours, with observations of the ovipositor in the female continuing for another hour. After observing success with coral rock substrate in the main tank, we have now added live rock to the breeding tanks.
- Peacock damsel (Pomacentrus pavo) – the pair continues to produce eggs on a regular basis.
- Seahorses (Hippocampus kuda) – on 14 March, internal eggs were observed in the female seahorse. We hoped this was in preparation for breeding around the full moon (18 March). The partnered male showed an enlarged abdomen and some quivering behaviours, indicating he would be receptive. Although the enlarged abdomen was maintained, there were no signs of developing fry, so we think the courtship phase is continuing.
- Sexy shrimp (Thor amboinensis) – following the production of eggs on the female, we have seen two clutches of eggs hatching successfully. For the first clutch, both females were relocated to a Kreisel tank to enable us to safely collect the larvae. Three larvae did successfully hatch, but they did not survive the first moulting. It is likely that the hatching occurred mostly before the females were relocated.
Learning from this, when eggs were observed for the second time, the female was immediately relocated to the Kreisel tank, allowing the eggs to develop. On 30 March, the eggs hatched successfully, and the larvae are being fed rotifers and Artemia, with a 30% daily water change as they begin moulting and growing.
Thor amboinensis larva at 1-day (Landaa’s Fish Lab)
Amphiprion clarkii eggs in an aerated flask (Landaa’s Fish Lab)
Small Marine Aquaria
After the aquarium flow issues last month (due to the unusual situation of having empty turtle rehab pools), we experimented with varying the seawater inflow. Unfortunately, this caused a surge of water pressure that overflowed both aquaria. Some fish residents were sadly lost, but the demersal and benthic fauna (living towards the bottom of the tanks) were unaffected. After the incident, four new fish specimens were kindly donated from the Dive Centre’s aquarium.
Aquarium One
- Mini coral frame – very healthy and full of fragments.
- Sea star (Linckia multifora) – continues to present a mild infection in one leg, which has shortened significantly in length.
Aquarium Two
- Mini coral frame – very healthy and full of fragments.
- Mushroom corals – constantly being misplaced by the crabs.
Our sea star has a mystery injury
New arrivals to the marine aquaria at Kuda Huraa
REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives
Monthly Progress
At Kuda Huraa during March, we transplanted nine new coral frames, and recycled two existing frames, using a total of 411 coral fragments from nine different species (mainly Acropora, plus Montipora foliosa).
During the last week of March, we helped with the major rescue of thousands of coral colonies from the large industrial development project at Gulhi Falhu (by the Maldives government).
At Landaa this month, we used almost 2000 coral fragments to transplant a total of 31 new coral frames (18 guest-sponsored, 11 Resort-sponsored, plus two online orders). In addition, we monitored (cleaned, repaired, photographed) more than 400 coral frames at various sites around Landaa Giraavaru. We also received a most generous donation that will enable us to make 54 new medium/large frames over the coming months, that will add an impressive 5600 coral fragments onto the reef.
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.
Our Reefscapers artificial reefs provide food and shelter for abundant species of marine life (coral frame on Kuda Huraa’s house reef)
Maldives Sea Turtle Rescue & Conservation
Maldivian Sea Turtle Identification Program
During March, we received an impressive 26 submissions of photo sets from the public to our Sea Turtle ID project. Our current database now catalogues 5,200 separate sightings, across 16 different atolls of the Maldives.
To date, we have positively identified and named a total of: 1337 Hawksbills, 280 Greens and 95 Olive Ridleys.
We have started trialling a new recognition software that uses the Citizen Science Wildbook ‘Internet of Turtles’. Photos of individuals that are not recognised using I3S software were added to this database to search the wider local network for a match. The trial also involves comparing the recognition success rate of I3S verses IoT using individuals with multiple images that have been sighted many different times. The trial is being conducted with the goal to establish one database for the whole of the Maldives’ turtle population.
Spotted a turtle? Share your photos
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.
Sea Turtle Rehabilitation
At the close of March, in our Rehabilitation Centre at Landaa, we were caring for:
– four Olive Ridley turtles (Lepidochelys olivacea), one Hawksbill turtle (Eretmochelys imbricata), two Green turtles (Chelonia mydas).
– see the corkboard (bottom of page) for more details of the turtles’ rescues and subsequent treatments.
At our Turtle Rescue Centre at Kuda Huraa, we welcomed Ari, our unreleasable (double-amputee) Olive Ridley turtle, from Landaa.
Turtle Nest Protection
On 16 March, we assisted with the emergency relocation of a Green sea turtle nest, in partnership with Maldives Environment Ministry and the Environmental Protection Agency. The turtle had been spotted laying eggs on a small stretch of sand in Malé City at around 04:00am. The authorities alerted our Marine Savers turtle experts, and we prepared a new nest on a suitable stretch of beach here at Kuda Huraa.
The eggs arrived by speed launch at 07:00am and were quickly and carefully buried in their new nest. Hopefully, we might see some hatchlings emerging from the sand in around 8 weeks’ time (15 May). 🤞
Turtle nest rescue – click to play video on Facebook
Excavation of sea turtle nest on a tiny beach in Malé, by the EPA and Environment Ministry
Turtle eggs transported carefully
We prepared a new nest on Kuda Huraa beach
Eggs about to be covered with sand
Further News & Updates
You might also be interested in:
– our ongoing Dolphin ID Project,
– our unique Sea Turtle Lagoon Enclosure, and
– our Zooplankton Monitoring Project (launched 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 juveniles.
