The Allen Coral Atlas: The first detailed coral reef habitat map and monitoring system

Chris Roelfsema and Chantal Say, Remote Sensing Research Centre (UQ RSRC)


The Allen Coral Atlas, which officially launched this spring, will revolutionise reef management. Led by CBCS’s Dr Chris Roelfsema, the team at UQ’s Remote Sensing Research Centre have digitally mapped geomorphic and benthic habitat in 253,000 km2 of the world’s shallow coral reefs as the mapping part of the Atlas.

This followed the launch in May 2021 of the Atlas’s coral monitoring tool, the world’s first satellite-based global coral reef monitoring system for coral bleaching and turbidity. The bleaching detection system identifies the brightening of corals by analysing satellite imagery which coincide with a bleaching warning from the National Oceanic and Atmospheric Administration Coral Reef Watch.

These data are now vital, with modelling predicting that 70 to 90% of the world’s coral reefs will be lost by 2050 due to ocean warming, pollution and acidification.

From the GBR to the world

Initiated in 2017, the Allen Coral Atlas team set out to build a freely available tool that could enhance and support reef science, conservation, management and policy-making. The initiative is an international collaboration between experts in the fields of reef science and earth observation to create a comprehensive global habitat map and monitoring system for coral reefs. The Atlas is named the late Paul Allen of Vulcan, who conceived and founded it, together with partners Planet, Arizona State University’s Center for Global Discovery and Conservation Science (who manage the Atlas), the UQ-RSRC and the National Geographic Society.

As part of the partnership, Dr Chris Roelfsema led the UQ RSRC team that developed and implemented the habitat mapping process which defines the geomorphic zonation and benthic cover for all shallow-water tropical coral reefs visible from space. The methods of the Atlas are based on original work by Chris and his team for mapping the Great Barrier Reef. These methods are based on combining over two million satellite images from Planet Dove and Sentinel 2 sensors and reference data in machine-learning classifier and object-based clean-up protocols.

The mapping team at UQ RSRC reached out to over 900 scientists and organisations from around the world, with over 400 teams generously sharing almost 500 of their own datasets to support our mapping efforts. UQ experts translated these data sets in over 600,000 geomorphic and 1 million benthic reference data points for training of the classifier and validation of the maps.

A tool for saving coral reefs

This innovative platform of the Allen Coral Atlas provides a unique opportunity for anyone, anywhere to make global comparisons between reefs, while also giving access to high-resolution habitat maps for reef features that have never before been mapped. The Allen Coral Atlas has already had an enormous positive impact on reef conservation around the world, helping researchers, conservationists and decision-makers achieve their goals. These have included proposing new marine protected areas, informing disaster risk assessments and prioritising reef restoration.

Visit the Allen Coral Atlas

Watch the video

Read the UQ News piece

Read the media release from the Minister for the Environment

Project members

Dr Chris Roelfsema

Senior Research Fellow
School of the Environment
Remote Sensing Research Centre