Reefscapers Diary September 2022

Baa Atoll Biosphere Coral Project

In partnership with Baa Atoll Council, Baa Atoll Biosphere, and multiple resorts in Baa, we were invited to take part in an atoll-wide coral restoration program for the local schools. This exciting project aims to educate school children on coral restoration work, and allows them to maintain their own coral ‘frame’ while collecting environmental data on survivorship, mortality, bleaching and growth rates. As part of the wider team, we visited a total of 13 different schools in Baa Atoll across two days.

Media Group

This month, our Reefscapers team held informative and engaging frame-building sessions, and participated in media interviews to explain the progress and successes of our coral propagation program.

• the ‘Earth Journalism Network’ that “enables journalists from developing countries to cover the environment more effectively”, and
• the ‘Bertarelli Foundation’ that “provides a global leadership in promoting marine conservation and science”.

Rescue Corals – Survival In Control Frames

Six months have now passed since our mass coral rescue relocation, and this month our team focused on monitoring these coral frames. We carried out seven scuba/snorkel surveys, each conducted by two to four people, each two hours duration. We manually counted all the mature colonies (≥ 20cm length) along with any primary/secondary causes of mortality, for a quantitative health assessment (0% to 100% healthy).

Results, after analysing our data collated from all 352 frames (of all sizes):

• 78% of coral colonies presented at least some live tissue (1-100%).
• 56% of coral colonies were in optimal health (71-100% healthy).
• Highest survival rates (71-100% healthy) were at the Shallow House Reef.
• Lowest survival rates were recorded in the Deep House Reef.
• Eleven different causes of mortality were identified, mainly “fallen’’ and “predation by corallivores’’.
• Turtle site – the “bleaching” was due to the relatively shallow waters.
• Shallow House Reef – the “fallen” corals were caused by strong wave action.
• Deep House Reef – affected by corallivores due to relatively difficult maintenance.
• Some coral colonies were buried under shifting sands and went uncounted (“sand smothering” will be under-represented).
• Predation from Drupella snails and Crown of Thorns starfish is a significant threat at several sites. Corallivores are known to prefer reefs that are stressed, bleached, or damaged (Bruckner et al. 2017).