Key theories in ecology surround the concepts of equilibrium in ecosystems and the role of disturbances in driving ecosystem function and diversity. Climate change brings not only chronic stressors to reef ecosystems, such as temperature rise and ocean acidification, it is also associated with predictions of increased acute disturbance events: cyclones/severe storms, heat waves, and flooding. This is all overlain with ever increasing human impacts. The degree to which acute natural disturbances will shape ecosystems compared, or in synergy with, chronic anthropogenic and environmental stressors is unknown.
Corals are among the greatest marine ecosystem engineers: providing habitat, protection and food and altering physio-chemical conditions for associated reef fauna. Understanding of the reliance of key fauna on the health and composition of the benthos is necessary if we are to develop targeted conservation strategies to promote ecosystem resilience. Changes in the benthos are arguably the most evident and quantifiable. Impacts to reef fishes are more difficult to measure, having higher short term variability and may be a direct result of disturbances or an indirect result facilitated through ecosystem processes and associations.
Ningaloo Reef, Western Australia, has been subject to multiple acute disturbances over the last decade, including cyclones, a heatwave and a flood. Due to a relative lack of local anthropogenic pressures in the global coral reef context, studies of the role of acute disturbances at Ningaloo Reef are comparatively free of confounding drivers.
Here I report on documented changes in benthic and fishes assemblages over a decade and report on how trophic and functional associations may drive indirect impacts following disturbances. With improved understanding of the processes driving indirect disturbance impacts to reef associated fauna – juvenile fishes, obligate corallivores, key herbivorous groups and important commercial fishes – management strategies may target specific ecosystem functions to promote resilience of whole ecosystems.