The Maldives Coral Institute (MCI) is fortunate to be the first recipient of the Ocean Resilience Philanthropy Fund, a new global philanthropic fund launched by Deutsche Bank in November 2021, dedicated to ocean conservation and coastal resilience.
The Ocean Resilience Philanthropy Fund’s support to MCI is being used for a multi-year programme of research culminating in the creation of a ‘Future Climate Coral Bank.’
As part of the programme, MCI will identify and map areas of greater coral reef resilience to coral bleaching in the Maldives, including a country-wide survey to ground-truth the conditions of coral communities. Once the MCI has identified reefs with high levels of resilience to bleaching, it will collect, propagate, culture and field test the resilient corals, and create a Coral Gene Bank resource for future reef restoration and assisted evolution efforts in the Maldives.
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Background
Coral reefs the world over have been significantly damaged by climate warming, which has caused mass coral mortality. The Maldives has been afflicted by two major global episodes of bleaching and coral death, in 1998 and in 2016. The first of these events caused a countrywide loss of 70 to 95% of coral, depending on location, whereas the second caused loss of half to two thirds of coral.
Studies in other parts of the world show that coral susceptibility to warming-induced mortality varies by depth and location. Some places have fared better than others, losing less coral and/or recovering more quickly, offering hopeful signs of resilience. A recent study undertaken by the Maldives Coral Institute collated information from multiple coral surveys undertaken since the 1950s. The findings suggest that reefs in the central and southern Maldives experienced less severe impacts from the two major global coral bleaching events and have recovered better from them than reefs in the north. Observations in the aftermath of the 2016 bleaching event showed greater coral mortality in lagoons compared to outer reef slopes of atolls, indicating that there is considerable variability in impact and possible resilience at smaller scales too.
There is an urgent need to identify and map variation in coral resilience in the Maldives to better direct and enhance national efforts to protect, recover and manage coral reefs for the benefits of local communities and national wellbeing. To achieve this goal, this project is proposed in three phases that each build on one another.
Phase 1: 6 months
Aim: To identify and map areas of greater and lesser coral reef resilience to warming-induced coral bleaching in the Maldives using a synthesis of pre-existing data
In Phase 1 we will create a country-wide map of coral resilience by collating information on patterns of coral mortality and recovery within and among atolls across the Maldives. To do this we will draw upon two nationwide reef surveys and will expand the recent analysis of long-term changes in coral cover in the country undertaken by the Maldives Coral Institute.
The Catlin Seaview Survey of reefs was undertaken in 2015, 17 years after the 1998 mass bleaching and one year before the 2016 bleaching event (http://www.globalreefrecord.org/home_scientific). It surveyed 31 sites across the country over 8 atolls. The second survey was by the Waitt Institute in 2020, four years after the 2016 bleaching, which surveyed 127 reefs across northern and central atolls. These two surveys will be complemented by expanding the Maldives Coral Institute study of long-term trends in coral cover. We will add further detail to this in the form of coral surveys that have not been published in the peer-reviewed literature, including those undertaken for Environmental Impact Assessments and other archived reports held in the Maldives.
Based on data from the three surveys we will analyse spatial patterns of coral cover across the country, identifying the timing and extent of coral losses due to bleaching events, and the rapidity and nature of recovery. By comparing coral cover change between repeated surveys we will (1) identify resistant reefs, i.e. those that lost the least coral during each bleaching event, (2) identify the most resilient reefs, i.e. those that bounced back most quickly from severe disturbance, and (3) map patterns of resistance and resilience across the country.
To maximise chances of identifying resilient reefs, in addition to the sites assessed in the aforementioned surveys, we will also seek reefs that have been observed to show evidence of higher resilience, and make field visits to conduct baseline surveys of these reefs. These sites will be identified via public consultation with divers, marine scientists, environmental consultants, resorts, and others in related industries, and will be included in subsequent surveys and analyses.
Future Climate Coral Bank Status Report (September 2022)
Phase 2: 12 months
Aim: To ground-truth and refine the reef resilience map by undertaking a country-wide survey of the condition of coral communities
The analysis and synthesis of existing coral data will require ground-truthing through field surveys of coral cover and reef habitat. We will undertake a countrywide reef survey, visiting sites previously sampled and adding new areas of interest based on the resilience maps created in Phase 1. The surveys will enable us to test and refine the resilience map based on the measured condition and ongoing recovery of corals. Recovery will be assessed through a variety of metrics, including coral cover, diversity and species composition, as well as other factors associated with reef health, such as high cover of crustose coralline algae, low cover of fleshy macro-algae and vigorous coral recruitment.
Phase 3: 30 months
Aim: To collect, propagate, culture and field test resilient corals, creating a coral gene bank resource for future reef restoration and assisted evolution efforts in the Maldives
Phase 3 is the most ambitious stage of the programme. In this phase we seek to determine whether corals from identified ‘resilient’ reefs are intrinsically more resilient to stress, or whether they simply occur in places that were, for various environmental reasons, less affected by the bleaching events or better placed to recover from them. We will collect corals from identified ‘resilient’ reefs, and others from areas identified as having the least resilient reefs. These corals will be established within a field lab facility and subjected to experimental tests to determine their ability to withstand heat stress. If resilience is intrinsic to the corals themselves, then corals from resilient reefs should withstand stress better than those from the least resilient reefs. Corals from different habitats and locations across individual atolls will also be tested in similar ways to determine small scale patterns of resilience.
If we can prove that some corals are more resilient to heat stress than others, we then need to test whether that can be passed on to offspring produced through fragmentation of colonies, or asexual or sexual reproduction. Success here will set the stage for a programme of coral propagation to (1) produce a coral gene bank of more resilient coral genotypes, (2) a source of more resilient corals to use in coral restoration efforts across the country, and (3) a source of corals that can be used in efforts to speed up coral adaptation to thermal stress (i.e. ‘assisted evolution’).
