Macroalgal removal on the reefs of Magnetic Island


Reef Ecologic Adam Smith with some freshly removed macro algae

On the Great Barrier Reef, many inshore reefs are experiencing increased macroalgae abundance and reduced coral cover. Macroalgae removal has been proposed as an active measure to aid reef recovery by increasing availability of benthic substrate for coral recruitment. However, the effects of macroalgae removal on reef community structure and ecology have not been rigorously investigated. While reef restoration is an emerging field, it is likely that no single intervention approach is sufficient. Hence, clearing space for coral recruitment by itself may not be sufficient to promote reef recovery, and thus effective restoration will require implementation of synergistic approaches. Combining algal removal with enhanced coral recruitment through capture and targeted release of coral larvae onto reefs represents one approach to fast‐track reef restoration. This project therefore aims to quantify the ecological effects of macroalgae removal on reefs and document the synergistic interactions of algal removal and enhanced recruitment on coral ‐ algal demographics.

Coral recruitment tile set in a cleared plot

The project involves a group of researchers from mutliple institutions: Associate Professor David Bourne, Dr. Ian McLeod, Hillary Smith from JCU, Dr Lisa Boström-Einarsson (Lancaster Environment Centre), Professor Peter Harrison (SCU), in partnership with GBRMPA, AIMS and Reef Ecologic.

This work is based on a pilot study led by Honours’ student Elissa Mastroianni. In this project, we cleared macroalgae from six quadrats between Arthur and Florence Bay prior to coral spawning in November 2018. Results from this study helped determine the viability of macroalgal removal as an intervention strategy to promote coral recovery on the reefs of Magnetic island.

Contact us for more information


Associate professor David Bourne



Find out more Email Us Phone 07 4781 4073