Coral Propagation – Monthly Progress
At Landaa during July, 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.
In June, we had started recycling the 123 coral frames in the “tagged” patch at Parrot Reef. We completed the work this month, performing four separate dives, and adding a total of 1,700 new coral fragments to our frames.
At Kuda Huraa this month, we transplanted five new frames, monitored 143 frames, and retagged 25 frames. In addition, our team has been very busy:
- relocating 120 frames at the Water Villas (lifting some from the sand, moving others back into full sun now the seasonal bleaching risk has past)
- relocating 250+ coral frames from the Blue Hole and Sunrise sites, to create a new coral trail to aid snorkelers around our reef
- starting work to repurpose and recycle hundreds of frames at the Channel site
NOAA Bleaching Warnings for The Maldives
Promising news for Maldivian corals, as July’s increased cloud levels and precipitation have reduced water temperatures as expected (and as confirmed by our strategically situated temperature loggers). NOAA’s Coral Reef Watch shows forecasted temperatures as “No stress”. The relatively cooler temperatures led to a visibly quick recovery for many of the stressed coral colonies, both on our frames and out on the reefs.
Coral Bleaching Study – Monitored Coral Colonies
- Two scuba diving surveys, ten snorkelling surveys, seven hours of monitoring, ten hours data analysis
- Bi-weekly surveys, 300 colonies representing nine different species, on 136 separate frames across five sites
- 78% healthy, 8% pale, 2% partially-bleached, 9% partially-dead, 3% dead
- The Channel is the most impacted site, with 61% healthy colonies
- The Starfish is the least impacted site, with 83% healthy colonies
- Acropora muricata is the most impacted species (56% healthy)
- Acropora digitifera is the most resilient species (88% healthy)
Corals recovering from paling, as they re-uptake symbiotic zooxanthellae
Channelling Action
Each year since 2016’s global mass bleaching event, The Channel coral restoration site at Kuda Huraa has been the most affected by the seasonally elevated ocean temperatures. Land reclamation work on the adjacent local island of Bodu Huraa has significantly reduced water flow in the area, leading to increased water temperatures and higher coral mortality rates.
Our Reefscapers team has been working hard to improve the Channel coral restoration site… A big thanks to the whole team for their dedication and tireless group efforts this month. We have been replacing dead coral with new fragments from neighbouring large healthy coral colonies, relocating healthy frames to areas of higher water flow, and grouping many cleaned frames for recycling, retrieving the frame tags as we go. More than 250 frames have already been freed-up for recoating and repurposing.
In the long-term, this will make our monitoring activities easier, streamlining our coral frame database, and will create a biodiverse snorkel trail for guests to enjoy. This trail will be made of coral frames that start on the reef crest and lead inwards towards the reef flat, where the Turtle, Sea Star and Lines sites are located. These areas are teaming with marine life, creating an effective showcase of our conservation work.
Reefscapers Coral Experiments
Micro-Fragmentation – At Landaa, we restarted our coral micro-fragmentation work with two ‘massive’ coral species, Porites lobia and Favia favus. We plan to see how successfully the fragments attach to the tiles and grow, before starting experiments to explore optimal conditions for survival and growth of massive species.
Wire Coral Frame Trials – At Landaa, we have been extending our research into methods of attaching coral fragments onto our Reefscapers frames. We will try to determine if the coral fragments can self-attach onto the frame as successfully as with our current plastic cable ties method.
Coral Cover Survey
Our intern, Sol, has been taking photo-transects to assess coral cover and diversity on various reefs around Landaa Giraavaru (House Reef, Sandbank, Voavah Sandbank). While processing the photosets, we have compiled a catalogue of observed species.
Two 10m transects were taken at each of three depths (10m, 5m, 3m). We used a PVC frame to hold the camera exactly 1m away from the 50cm quadrat placed along the transect. Close-up photographs were then taken of any corals within the quadrat, to enable accurate ID of coral genera. To estimate coral cover and diversity, CPCe is used to project 25 stratified random points onto each quadrat, and corals under these points will be identified to genus level and their morphology noted.
