Standard Talk (15 mins) Australian Society for Fish Biology Conference 2022

The functional roles of surgeonfishes on coral reefs (#67)

Sterling B Tebbett 1 , Alexandre C Siqueira 1 , David R Bellwood 1
  1. James Cook University, Townsville City, QLD, Australia

Surgeonfishes have had over 50 million years of evolutionary history in close association with coral reef ecosystems. Today, these fishes make up a core component of reef fish assemblages and contribute to a range of ecosystem functions. However, as coral reefs are being reconfigured by a suite of stressors, the relative importance of surgeonfish functional roles may be changing, and we must now understand these roles in this context of change. To do this, our work explores how functional frameworks can be applied to clarify how fishes interact with their environment. In the case of surgeonfishes, clustering based on morphological and behavioural traits results in six broad functional groups: browsers, brushers, croppers, concealed croppers, sediment-suckers, water-column feeders. Based on these functional groups, we outline how the functional roles of surgeonfishes on coral reefs have evolved over the past 50 million years in different biogeographic locations. In addition, we highlight how surgeonfishes from different functional groups contribute to several key ecosystem functions (e.g., macroalgal removal, algal turf removal, detritus removal, sediment dynamics, plankton harvesting and cross-habitat trophic linkages), while also considering how the nature and importance of these roles may change in the future. Specifically, we focus on the interactions between surgeonfishes and algal turfs, a group of algae expected to typify coral reefs in the Anthropocene. Importantly, these interactions can be shaped by stressors such as sediments, with flow-on consequences for the services that surgeonfishes provide to people.