Close look at a maxima clam (Tridacna maxima)
Fish Lab, Aquaria, and Marine Life in the Maldives
Plankton Production
Our plankton and algae cultures are used as the main food source for the residents of our Fish Lab.
– Microalgae (Nannochloropsis) – Overall, 400L of algae were produced throughout the month, plenty for our requirements.
– Rotifers – Population density decreased dramatically during the second half of the month. To ensure the rotifer batch wasn’t lost, a sample was collected and added to a new 100L bucket full of live Nannochloropsis algae. We reduced food per session from 2.5mL to 0.5mL microalgae, given 3 times daily.
– Brine shrimp (Artemia) – culture has decreased from 5g to 3g of cysts a day as our moon jellyfish population is reduced.
Fish Lab Breeding Programmes
- Clark’s anemonefish (Amphiprion clarkii) – The couple living in tanks 3 and 5 produced 3 and 2 batches of eggs this month respectively. No larvae were collected this month. [Lifecycle graphic]
- Dancing shrimp (Thor amboinensis) – No larvae were collected this month.
- Boxer Shrimp (Stenopus hispidus) – a new male has been added to tank #13.
- Moon Jellyfish (Aurelia aurita) – 500+ outgrown individuals were transferred into a 30L Kreisel tank, with larger individuals moved to a 40L tank to free up space. Unfortunately, most of the individuals died due to lack of maintenance; we did save 93 individuals from the new batch. Additionally, a total of 166 growing jellyfish from the 85L Kreisel were all transferred to our large display cylinder.
Groupers (Epinephelus fuscoguttatus) – Overall, 5 of our growing-out groupers died this month. The largest fish (570g) was delivered to the Kitchen Department for a special trial, leaving a total of 494 thriving fish. Feeding mass has increased slightly from 2.0kg to 2.1kg.
Sea Grapes (now known to be: Caulerpa racemosa)
Due to an increased demand for sea grapes from the Kitchen Department, we are attempting scale up production. We harvested 2 batches of ~500g each from the Kamadhoo jetty, but we were unable to establish them in our grow-out sea ponds. We then harvested 3kg from Kihadhoo, with added barrier protection from grazers and improved concrete walls in our pond. Water flow is provided directly from the outflow-pipe from our grouper tanks. Overall we delivered 750g of fresh sea grapes to the Kitchen.
Clam Collection
We were excited to discover a number of baby giant clams inside our coral spawning device! These juveniles had settled naturally within the structure, so we carefully collected them up and brought them back to our Fish Lab for safekeeping and observation. To provide a stable substrate, we created small concrete pockets, individual bases that allow the clams to attach securely while giving us the flexibility to relocate them as needed. In total, we have 16 juvenile clams, all of which appear healthy and active. We’re currently considering the best long-term placement for them, with potential sites including the sea grape system, the coral holding tanks, or even the main display tank. This approach will allow us to observe their growth and survival in different environments while ensuring they remain protected and easy to access for monitoring.
Why are giant clams good for marine aquaria? Clams play an important role in maintaining healthy marine systems. They help to improve water quality for other residents by naturally filtering the water, reducing excess nutrients. Clams also stabilise substrates and add biodiversity and interesting colour features to tank environments.
Guest Excursions
At Landaa Giraavaru this month, 57 guests enjoyed 17 guided tours of our Marine Discovery Centre. We also conducted 8 Guided Adventure Snorkels, 1 Night Snorkel, 6 Parrot Reef Snorkels, 10 Shark Safaris, 10 Turtle Safaris, and 3 private trips, for a total of 239 guests. We were very fortunate to encounter multiple reef mantas at a cleaning station there, in addition to many green and hawksbill turtles.
At Kuda Huraa, 172 guests enjoyed 27 excursions to 6 different sites close to our Resort, and we recorded sightings of 12 megafauna species.
Our first-year apprentices have been enjoying their hands-on time with our conservation projects, and their enthusiasm for learning is contagious! From learning how to give guest tours and answer guest questions, to assisting our veterinarian analyse the blood samples from our turtle patients. It is always exciting to train people with genuine interest in learning about marine biology and the environment. And so our apprentices leave us for their next departmental placement as environmental ambassadors, with the ability to engage with work colleagues about the importance of active conservation.
Junior Marine Savers
Six children enjoyed our Junior Marine Savers activities this month at Kuda Huraa, learning about marine biology. These curious young minds have the chance to learn about turtles, corals, and cetaceans while spending a morning with our marine biology team. They are given a presentation about the different specialised marine species, and then participate in hands-on activities such as turtle feeding, building a coral frame, or helping identify different dolphins with our identification software. These activities are then followed by a snorkel at one of our restoration sites, where the kids can see some of the species that we spent time learning about. It is such a pleasure having so many interested participants wanting to learn more about our oceans and how to help our environment with such a passion!
Maldives Sea Turtle Rescue & Rehabilitation
Turtle Nest, Landaa Beach
On 26 October, our hawksbill turtle nest successfully hatched on Landaa’s beach! Our new nest-monitoring camera worked perfectly, allowing us to remotely monitor the nest throughout the nights leading up to the expected hatching date. The first sign of an imminent emergence was the appearance of a circular depression, in the late afternoon. Initially, only three hatchlings were observed, resting at the surface until sunset. Over the next 2.5 hours, the hatchlings started emerging from the sand in increasing in frequency, peaking in the early evening. We ensured that all the hatchlings made it safely to the ocean with the help of our red flashlights.
On the following day, we excavated the nest (standard marine practice) to record: 80 empty shells and 27 undeveloped eggs (a hatching success rate of ~75%).
Sea Turtles Released with Satellite Tracking Tags
Follow the journey of Harry our Olive Ridley sea turtle patient, recently released with a satellite tag to enable us to monitor their journey in the big blue. Visit our turtle page or our dedicated project page for more details – Turtle Satellite Tracking. Harry seems to have reached a favourite wide-area feeding ground, and is maybe building up strength.
New Rescue Turtle: Toby “October”
This month, we admitted a juvenile hawksbill turtle nicknamed ‘Toby‘ into our Sea Turtle Rescue Centre. He was spotted on the shore of the neighbouring local island of Huraa, in a very weak and dehydrated condition. Our resident veterinarian performed various health checkups, including an ultrasound and an endoscopy, and he is currently under antibiotic treatment. After just 1 week, Toby is thankfully showing remarkable improvements, so we are hopeful of a quick release in the coming weeks!
REEFSCAPERS Coral Propagation & Reef Restoration in the Maldives
At Kuda Huraa during October, our coral experts monitored (cleaned, repaired, photographed) a total of 61 growing coral frames, and transplanted 6 new frames, kindly sponsored by guests (4), the Resort (0), online (0) and recycled (2). In addition, we repopulated 55 growing coral frames at various sites around the island.
The team have also been very busy working to improve our Channel restoration site. All the guest frames in this area have been monitored, and buried frames have been lifted from the shifting seasonal sands.
A standout occasion this month was welcoming Jackie and Rob to Kuda Huraa. Their generous donation helped facilitate the coral-relocation project in April this year, leading to the creation of Noah’s Rock. We were deeply honoured to host them, so to commemorate their wedding anniversary, we built a heart-shaped coral frame and out-planted it all together at Noah’s Rock. We are enormously grateful to the family for their kind support of our coral propagation projects.
At Landaa this month, we monitored 160 existing frames (mainly at our Bissie’s Reef site), and transplanted 25 new coral frames, kindly sponsored by guests (7), the Resort (17), and online (1). In total, we added ~1000 new propagated coral fragments to the reef. Frames were planted at our “Plankton” site for curious SCUBA divers, and around the Water Villas for curious guests.
Reefscapers intern Libbie has continued to lead our major project to recycle and repopulate the coral frames at the Water Villas site. She will be leaving us soon, but has completed a detailed method guide to ensure the project continues into the future.
To see the progress of your own frame, please visit our dedicated Reefscapers Four Seasons monitoring page where we upload new photos every 6 months or so.
Coral Spawning – October Full Moon
On the runup to October’s full moon, we performed gamete checks on various coral colonies, and observed a range of eggs from white (immature) to orange (mature and ready to spawn). Our expanded team of divers were eager to witness coral spawning, and the reef did not disappoint! We were thrilled to witness several coral genera releasing their gametes in a wonderful natural display.
Further News & Updates
You might also be interested in 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.
