Coral Reef Resilience

Despite containing some of the healthiest coral reefs in the Indian Ocean, the impact of climate change has been felt acutely in BIOT and resulted in extensive bleaching of coral reefs in both 2015 and 2016. Scientists from the Bertarelli Programme in Marine Science are therefore monitoring how the reefs respond over the next four years. To do so, the researchers are studying not only the biology of the coral animal itself, but also the physical structure of the reef as a habitat and the biodiversity living within it.

BIOT offers one of the few global sites where it is possible to undertake long-term monitoring to document change in the near-absence of localised pressures from human activity, such as fishing and pollution. Scientists are adding to their long-term time datasets of BIOT coral reefs which will make a globally significant contribution to our understanding of coral reef biology and will help with their conservation. This work includes:  video monitoring of benthic communities; measuring changes in sea surface temperature; documenting the rate of recruitment of juvenile corals; and comparing recovery rates and coral cover on reefs adjacent to those islands with healthy seabird populations and those which are infested by rats.

Programme scientists are combining climate science theory with reef surveys to quantify their 3D- structure and growth rates, and to assess the vulnerability of BIOT’s reefs to future climate change scenarios. Working collaboratively with MPA managers, researchers are helping to identify possible actions which will reduce vulnerability to likely changes.

To understand the status and resilience of the key communities of coral-reef fishes that make up the ecology of the BIOT MPA, scientists are continuing their existing long-term monitoring programmes.  This work includes a wide range of investigations: documenting the human alteration of habitats;  seeing how the removal of top-order predators impacts reef health; observing how changes in climate are affecting the structure of fish communities; and considering the influence of seabird colonies on the structure of reef fish communities.

Using traditional ecological and new molecular techniques, scientists are assessing micro-habitats across the reef environment to explore the biodiversity of the incredible crypto-fauna that live within them.

By assessing the prevalence and progression of coral diseases in BIOT we can discover the susceptibility and resilience of key coral species to those infections. An assessment of genetic variation in the host corals and the coral’s associated micro-organisms will also enable scientists to relate disease occurrence and bleaching history to genetic variation in the coral populations.