Maturing gametes in Acropora corals – range of colour pigmentation (Kuda Huraa, November 2021)
Coral Propagation – Monthly Progress
At Landaa during November, we transplanted 26 new coral frames, sponsored by guests (16), the Resort (9), and online (1), using a total of 1311 coral fragments. We also monitored (cleaned, repaired, photographed) a further 238 coral frames at various sites around the island.
- Simon (our MDC Manager) and Margaux (our Coral Biologist) were interviewed by local news media – Dhauru and Mihaaru – to highlight the success of Reefscapers coral spawning and settlement research.
- The International Ocean Institute (Maldives Branch) reached out to us, to discuss the Reefscapers coral spawning and settlement work. We participated in an online presentation to inform participants about our work, sharing photos and video along with our results to date.
At Kuda Huraa during November, we transplanted 3 recycled frames and 13 new frames, sponsored by guests (12) and the Resort (1), using a total of 914 harvested coral fragments (from 11 different Acropora species). We also monitored 38 frames at the Blue Hole, and emailed kind sponsors with photo updates.
- House Reef (HR) – a flourishing site, and home to this month’s 16 coral frames, along with some relocated Water Villas frames.
- Water Villas (WV) – this site continues to suffer from the seasonally shifting sands, so we have been busily relocating approximately 60 of the frames to deeper waters. Since April 2021, a total of 775 frames have been relocated to other sites, but we have lost 30 frames due to the sand encroachment (which are being recycled).
- Blue Hole (BH) – during our regular cleaning and maintenance at this site, we observed that all the coral colonies remain healthy (newer fragments are now fusing to the frames).
- Channel (CH) – we continue to retag and retransplant these frames, however, many of the newly transplanted coral fragments are targets of fish predation. October’s frames are also in poor health (including our experiments with blue coral, Heliopora coerulea), so we will retransplant where necessary, and pause the deployment of new frames at this site.
- Sea Star (SS) – this site experiences slightly higher ocean temperatures, and exhibits lower biodiversity, but corals seem well-adapted to the conditions and are healthy overall (apart from some predation by the resident parrotfish and trigger fish).
We have continued to monitor for new signs of coral spawning by carrying out night surveys from 20 to 25 November. Since 21 October, coral eggs have been sighted in five different species of Acropora, and we have successfully recorded coral spawning on 27 different frames (mainly at the Water Villas site).
Three spawning events were recorded this year (27 October and 24-25 November), and there may be additional events due to similar tidal patterns in October and November, plus reports of other spawning events in the Maldives. Following the two November spawning events, eggs have been observed in several Acropora species (A. gemmifera, A. tenuis, A. humilis, A. plantaginea). Additionally, we have observed that not all mature coral colonies of the same species have produced eggs (asynchronous spawning – weeks apart and for the same species – is a known phenomenon even within the same site).
Coral Plates in Aquarium One (plates KH01, KH02, KH05) and Aquarium Two (plates KH03, KH04, KH06)
• KH01 (Galaxea fascicularis; Acropora species replenished Sep-Nov 2021) – new fragments are starting to grow; additional fragments of Acropora plantaginea and tenuis were added, as the blue corals (Heliopora coerulea) did not survive.
• KH02 (G. fascicularis) – fragments are stressed and darker brown in colour.
• KH03 (Acropora species, replenished Oct-Nov 2021) – the newest fragments are already well-encrusted to the plate; replenished with additional Acropora fragments this month.
• KH04 (Acropora species, mushroom coral; replenished Oct-Nov 2021) – fragments are healthy. Two mushroom corals have been added (after three days of quarantine) and are adapting well.
• KH05 (G.fascicularis) – fragments are in good health. The plate continues to accumulate cyanobacteria, which is regularly removed.
• KH06 (G.fascicularis) – fragments are healthy and growing well.
Coral Spawning Event in the Maldives, November 2021
Please see our indepth report and full coverage of the November coral spawning event, and learn how we collected coral spawn to successfully grow tiny coral polyps in our laboratory!