Fish Lab & Aquaria -Marine Life in the Maldives
Newly introduced cardinal fish in our large 4000L display marine aquarium
We are starting to raise damsel fish in our Fish Lab, to assess the viability of a long-term breeding program. Their eggs are laid every three days (a much higher yield than anemonefish) but the larvae are thin and delicate. We are continuing to experiment with different food quantities, to gauge the correct Nanno3600 rotifer concentrations (in a 50L tank, 10ml proved excessive, as did 2ml with 1L of live algae).
Large Aquarium
This month, we collected some new specimens of small fish (including sweepers, cardinals, and damsels) and added some sea hares and a sea cucumber from our outdoor tanks (to regulate the growth of algae). We also rearranged the living corals into a more natural-looking reef display to optimise full use of the space.
Plankton Production
- We have successfully reduced our Rotifer concentrations, with 20% harvesting per day for the coral and main tank feeds.
- We have started growing Artemia in our two outdoor 100L algae tanks, but survival rate is low (we think due to higher than optimal air temperatures). We are having continued success with the 2g/2L/day Artemia in the lab, which is ample to supply the Fish Lab.
- Algae – following the die-off of one batch, we restarted the smaller cultures and have returned to normal production.
Fish Lab – stable rotifer population this month (1 to 31 August)
Aquarium One
- Mushroom coral – continues to regain colour and exhibit good health.
- Mini coral frame – continues to be healthy overall. The older coral fragments are stable with evident growth, whereas the newer fragments are recovering from the stress of transplantation.
- Mantis shrimp (Odontodactylus scyllarus) – a new resident is sighted occasionally.
- Sea star (Linckia multifora) – continues to show variations in arm lengths, but otherwise appears healthy.
Aquarium Two
- Clark´s anemonefish (Amphiprion clarkii) breeding pair – laid eggs on 21 August in their usual area.
- Mini coral frame – coral fragments are healthy and growing.
- Sea star (Linckia multifora) – observed with infectious wounds on two arms (attack by crabs?) so we have quarantined it temporarily.
Aquarium-2: seastar wounds
Seastar wounds
Aquarium-1: sea star regrowth
Sea star regrowth
Aquarium-1: mini coral frame
Mini coral frame
Aquarium-1 mushroom coral recovery bleaching
Mushroom coral recovery
Jellyfish – Aurelia aurita
We have completed a strobilation with a single tile from the polyp tank, stopping the count at 1500 ephyra. Once these individuals have grown large enough for our smaller Kreisel tanks, we will start a new strobilation batch.
We have initiated a new project to replumb our large Kreisel display cylinder, to run it as a closed system. We plan to use an existing 500L chiller with a new pump, for a maximum circulation flow rate of 1000L/hr. The new pump will be capable of 4000L/hr, for possible upgrade to a Hailsea 1000L chiller in the future. A new 39W UV steriliser (2000L/hr) will have an upgrade potential to 80W (4000L/hr).
Aurelia jellyfish ephyra
Zooplankton Study
After consultation with the manufacturer, we will start to clean our flow meter with fresh water and vinegar after each use (no need for complete disassembly). We have ordered a ‘spin checker’ to ensure the flow meter is working correctly and accurately, eliminating the need for calibration tows.
The next challenge is to increase confidence and accuracy of our zooplankton identifications, so we have purchased a range of step-by-step ID guides from plankton experts.
Many thanks to our overseas mentors at MBA [UK] (Dave Conway) and CSIRO [AUS] (Dr Anthony Richardson and Frank Coman).
REEFSCAPERS Coral Propagation & Reef Regeneration in the Maldives
Monthly Progress
During August, we transplanted 33 new coral frames around both resorts, using more than 1500 coral fragments for our transplanting and maintenance work.
Check out our Reefscapers Diaries page 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 continue our microfragmentation project, and start propagating Blue corals for the first time.
Sea Turtle Rescue & Conservation
Raai was fitted with a satellite tracker and released on released on 14 August. Follow his progress on our interactive map !
Sea Turtle Rehabilitation
At the close of August, we were caring for 5 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 3 Hawksbills.
Sea Turtle Enclosure
Our large turtle enclosure is located in the lagoon at Landaa. This month, Raai spent two weeks in the rehabilitation pen, learning to dive and to rest on the bottom netting, before being successfully released on 14 August, fitted with a satellite tracker (19U2125). Check out our interactive map to track his progress!
On 15 August, we transferred Oevaali out to the enclosure. Within a few days, she was successfully diving down to retrieve food, so in the coming weeks we hope to see her resting comfortably on the bottom netting as she overcomes turtle buoyancy syndrome.
Attaching Raai’s satellite tag
Raai all ready to go!
Raai was released on 14 August
Flying Turtles
On 29 August, our long-term resident Olive Ridley turtle, ‘April’ was transferred from Landaa to our turtle rehabilitation facilities at Kuda Huraa, in preparation for her journey overseas. April remains stable, but her buoyancy syndrome persists. She has a healthy appetite and tries hard to dive during her daily exercises and ocean swims. She is interacting well with all the pool enrichment devices.
We held a group conference call to discuss logistics with our overseas partners, and we plan to fly April to Europe in the upcoming weeks.
National Red List Workshop
The Maldives Ministry of Environment, Environmental Protection Agency, Marine Research Institute, and the IUCN participated in an IUCN Red List “Threatened Species™ Assessor Training Workshop”. This virtual Zoom workshop is part of REGENERATE (a government project, implemented by IUCN) and was facilitated by James Tallant (Ecosure).
There were sessions on key terms and concepts, the nine Red List categories, the five Red List criteria, and their application at national/regional scales, as well as discussions to start creating a Maldives National Red List.
Work groups have been set up, and Marine Savers is part of the sea turtle team (leading the Hawksbill species group) where we discussed collating national information and data on the five species of sea turtles seen in the Maldives.
Maldives sea turtle identification project – the most frequently sighted turtles in our database
Maldivian Sea Turtle Identification Program
During August, we received 17 submissions of photo sets from the public to our Sea Turtle ID project. Our current database catalogues 5,000+ photographic sightings, and to date has positively identified and named a total of: 1312 Hawksbills, 274 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
Further News & Updates
You might also be interested in our Dolphin ID Project, and our unique Sea Turtle Enclosure out in the lagoon at Landaa.
Looking for details of our Reefscapers coral propagation and reef restoration program ?
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.
Spinner dolphins photographed as part of our Dolphin ID Project – we have taken thousands of photographs, and individually identified more than 500 dolphins (Spinners & Bottlenose) and Pilot whales, thanks to the unique shape and outline of their dorsal fins.
