Project

Checking up on corals – bleaching events and recruitment

Species
  • Corals
  • Other species
Type
  • Long-term
Status
  • Current
Category
  • Research
Description

We monitor the health of the coral reefs around D’Arros Island and St Joseph Atoll using various indicators, including ambient environmental parameters, benthic cover and composition, coral recruitment and coral bleaching events. Data collected from our long-term monitoring of reef fish communities are also incorporated as an indicator of reef health. The work to acquire this data is extensive, including a lot of dive surveys, photo analysis and environmental monitoring. Our staff take about one month of every year to fulfil all field-work requirements.

ADDITIONAL PROJECT LEADERSOSF-DRC current management
Project details

Coral monitoring survey

Key objective

The aim of this project is to assess trends in the health of coral reefs at D’Arros Island and St Joseph Atoll.

Why is this important

The dynamics of coral reef ecosystems are complex and varied, with many different processes interacting. There is a need to monitor reef dynamics and health over the long term to better understand their function and the causes of bleaching events, as well as the ability of reefs to recover from them.

Background

Coral reefs form the basis of some of the most diverse marine ecosystems in the world. Despite only occupying 0.1% of the world’s ocean area, they provide a home for about a quarter of all marine species at some point in their lives. In terms of their value to us, coral reefs are a huge food and tourism resource that supports millions of livelihoods. They absorb energy from waves and contribute to environmental protection by reducing coastal erosion.

Research has shown the widespread destruction of reefs in recent decades and the associated population declines of reef-dependent marine species. One third of reef-building corals are currently on a trajectory to extinction. Coral reef bleaching is a major component of this destruction and occurs when corals expel symbiotic organisms called zooxanthellae. This expulsion is a stress response by corals that is most often brought about by increases in water temperature that, due to global climate change, are occurring more frequently and for longer periods.

In the face of ever-growing threats to reef systems, dedicated and long-term research can uncover patterns in coral reef health and disturbance regimes.

Aims & objectives

The key objective of this project is summarised in four sub-objectives that each address different indicators of coral reef health:

  • To monitor the changes in water temperature across the site;
  • To record the benthic cover and composition of the reefs;
  • To monitor long-term changes in the distribution and abundance of coral recruits (successfully settled new corals);
  • To investigate the severity and extent of coral bleaching events.