Fish Lab & Aquaria – Marine Life in the Maldives
This month, we have added a one spot damsel (Chrysiptera unimaculata) to our Fish Lab, plus the guest favourite from the main tank, a six spot sleeper goby.
Plankton Production
- Algae – culture is consistently cycling
- Artemia – production is keeping up with the demand of the main tank at 4.5g of cysts a day
- Rotifers – volume has recovered completely after last month’s drop, and is consistent in concentration
- Copepods – on 11 July, we established our very first copepod culture, which continues to develop and stabilise. Concentration is gradually increasing, and we may need two buckets in the coming weeks, allowing for more damselfish breeding
Jellyfish – Aurelia aurita
All mature jellyfish continue to thrive in our large display Kreisel cylinder. The small Kreisel jellyfish were unfortunately lost due to issues with water changes, so we started a new strobilation that should be ready for collection in September.
Seaweed Mariculture – edible sea lettuce (Ulva lactuca)
We are making progress with our experiments into seaweed mariculture (marine farming). Our new starter culture of edible sea lettuce (Ulva lactuca) has arrived, and is now getting established in the large outdoor tank. We have made a fertiliser drip-feeder to maintain good nutrient levels, and installed the new shade to reduce over-heating (while allowing sufficient sunlight for good growth).
Anemone Asexual Reproduction
The aim of our new project is to reproduce several species of host anemones and integrate specimens onto the house reef to create a ‘soft coral garden’. This will present a healthier biodiverse ecosystem, and provide hosts for various species of Crustaceans, Pomacentrids and Thallasids.
We have started a preliminary trial on asexual reproduction of the anemone Entimacea quadricolor. Akin to Scleractinians, anemones can also be fragmented into smaller sister colonies. Precise incisions through the oral disc and pedal disc of the test anemone have yielded two healthy sister anemones with a reformed mouth, providing them with full feeding functionality.
Megafauna and Marine Life in the Maldives
At Landaa, our Marine Discovery Immersion Tour was enjoyed by 67 guests during August, and a total of 638 bookings were taken for the 49 excursions guided by our team members.
At Kuda Huraa, a total of 405 bookings were made for our guided marine excursions, including the Dolphin Cruise and numerous adventure snorkel trips. This month, we launched a new guest excursion, ‘Shark & Ray Snorkel’, to get up close and personal with some of the ocean’s most majestic fishes, rays and sharks. Our accompanying marine presentation is entitled ‘Close Encounters’, as we seek to alleviate fears of swimming with sharks, and encourage our guests to swim safely with, interact and understand them. We have coincided this with the start of the Four Seasons ‘Championship Surf Trophy’ here at Kuda Huraa. Many professional surfers don’t see eye to eye with sharks, so we wish to highlight the serene, peaceful nature of sharks and foster a newfound understanding and fascination for these misunderstood marine creatures.
This month’s 31 diving excursions gave us abundant megafauna sightings, including nurse sharks (Nebrius ferrugineus), white tip reef sharks (Triaenodon obesus), and black tip reef sharks (Carcharhinus melanopterus). We also encountered healthy populations of pink whip rays (Pateobatis fai) and plentiful manta rays.
Ornamental Fish & Shrimp Breeding
Ornamental Shrimp Breeding
- Sexy shrimp (Thor amboinensis) – More larvae have successfully settled and been transferred to the display tank. Our current population stands at 60 shrimp, 47 of which have been bred in-house. We also had our first fourth generation larvae (F3) that are the ‘great grandchildren’ of our initial pairs. These are the offspring of our F2 juveniles that went through protandric sex change at the start of the month and have now established pairings. There are seven females in this group now, of which four are brooding. We collected two spawning events, totalling 479 larvae that are brooding in our Fish Lab. Last month’s F1 generation has been transferred to the settlement bucket.
- 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
- Blue damelfish (Pomacentrus pavo) – eggs from last month hatched successfully. Previously, we have been unable to grow this species beyond Day-3 as both rotifers and Artemia are too large as food, but using our newly established copepod culture, we have managed to reach Day-9. With greater concentrations of copepods, we hope to rear a new clutch in the coming weeks.
- The Clark’s larvae are now quite large and are ready to be introduced to our fake anemone. The breeding pair produced three clutches this month.
- Three new pufferfish (two females and one male) were collected on 27 August and housed in an upper-level tank to reduce stress. We observed spawning behaviours and subsequent production of an egg/sperm mass, which we relocated to a Kreisel tank in our Fish Lab for hatching.
Maldives Sea Turtle Rescue & Rehabilitation
Monthly Updates
At the close of August, we were caring for 2 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.
Lhaviyani Turtle Festival
The Lhaviyani Turtle Festival was a great opportunity to meet and engage with local islanders, school groups and council members, who had travelled from the islands of Lhaviyani Atoll and Baa Atoll. Our short presentation explained turtle conservation and rehabilitation, and the following Q&A and panel discussions covered topics from NGOs, Naifaru Juvenile, and the wider conservation and waste management efforts of the Maldives.
Maw’s Spa Treatments
Research shows that sea turtles in the ocean get a little help from reef fish to clean their carapace (cleaning symbiosis). Here in our Turtle Rehabilitation Centre, we provide weekly spa treatments to wash Maw’s carapace and flippers with iodine, and coat her shell with a layer of Vaseline (to prevent moisture loss when stuck floating on the surface due to turtle buoyancy syndrome).
- Sazima, C.; Grossman, A.; Sazima, I. (2010) “Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the SW Atlantic“. Neotropical ichthyology, 8(1), 187-192.
- Mellor, David J. 2017. “Operational Details of the Five Domains Model and Its Key Applications to the Assessment and Management of Animal Welfare“. Animals 7, no. 8: 60
Fluid treatment for MAW
Lhaviyani Turtle Festival 2023
Prosthetic Flipper
Animal welfare is concerned with quality of life (Bracke 1999), with five key considerations: nutrition, environment, health, behaviour, mental state (Mellor 2017). Animal welfare is further described by ‘The World Organisation for Animal Health’ (WOAH) as a healthy animal that is comfortable, well nourished, safe, able to express innate behaviours, and not suffering from pain/fear/stress (OIE 2016).
Turtle amputees can struggle with common tasks such as swimming and diving, affecting behaviours and mental state. Assistive therapy can (partially) re-enable these activities, providing comfort and reducing stress (Cook 1995; Bugwardt 2017).
This month, our team decided to learn more about the practicalities of creating prosthetic flippers for Maw. We studied the published literature on prosthetic limbs, and researched turtle anatomy, flipper components, and the biophysics of locomotion. We have also started designing a complex 3D-printed model, which we hope to produce in-house in the coming weeks… stand by for updates!
- Bracke, M, et al. “Overall animal welfare assessment reviewed. Part 1: Is it possible?” Netherlands Journal of Agricultural Science (1999): 279-291. OIE, 2016.
- Mellor, David J. 2017. “Operational Details of the Five Domains Model and Its Key Applications to the Assessment and Management of Animal Welfare“. Animals 7, no. 8: 60.
- Cook & Hussey (1995). Assistive Technologies: Principles and Practices. St. Louis, Missouri.
- Bugwardt, F, et al. (2017) “Designing a Biomimetic Prosthetic Flipper for a Kemp’s Ridley Sea Turtle“. Worcester Polytechnic Institute.
Maldivian Sea Turtle Identification Program
During August, we received 20 new photo sets submitted by the public. Currently, our database contains uniquely identified totals of: 1455 Hawksbills, 303 Greens and 97 Olive Ridleys (from 5500+ separate sightings taken across the Maldivian atolls).
We are currently processing our backlog of images, with 21 new individuals identified this month, including “Nonami” (EI1160), first photographed and identified at Velaa Faru back in 2018, and resighted just a few weeks ago swimming on our House Reef at Kuda Huraa.
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 Kuda Huraa during August, we transplanted 18 new frames, kindly sponsored by guests (12), online (one), and the Resort (five). We monitored and repaired 226 frames around the island, and re-mapped the frames along the Shallow House Reef and Reef Crest sites using Garmin GPS. We have also been relocating Montipora digitata colonies at the Water Villas site (to reduce competition and stress) and retransplanting any heavily stressed frames following the recent periods of coral bleaching and subsequent predation.
At Landaa this month, we transplanted 28 coral frames, kindly sponsored by guests (eight), online (two), and the Resort (18), adding a total of 1400 coral fragments to the reef. In addition, we monitored (cleaned, repaired, photographed) a total of 575 coral frames at various sites around the island.
We are continuing our large-scale recycling and maintenance work, lifting buried frames from the seasonally shifting sand, and recycling any fragments on degraded frames. This month, we raised 206 partially buried frames along the Coral Trail, Anchor Point, and Blue Hole sites, and added 1445 new fragments where necessary.
Reefscapers Coral Research Experiments
- In July, we restarted our coral micro-fragmentation work with two ‘massive’ coral species. We want to see how successfully the coral fragments attach to the tiles and grow, before expanding the scope in future months. Initial observations are already showing some health differences between fragments.
- Also last month, we restarted 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. We continue to monitor health and growth of all the test fragments.
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.
