Abstract:

Coral reefs are hyper-diverse ecosystems that provide important ecosystem services and goods to many millions of people. Yet, coral reefs are rapidly declining from global climate change and local human stressors with many reefs now being overgrown by large fleshy macroalgae (or seaweed). While the causes of reef degradation are relatively well established, there is limited knowledge on how critical ecosystem functions, such as herbivory, will respond to these changes. Herbivory mediates coral–algal competition, and is a key process determining the benthic community structure and resilience of coral reefs. However, we have a limited understanding of how structural elements of the ecosystem influence patterns of habitat use, foraging and functional impacts of herbivorous fishes on degraded reefs or those shifting towards macroalgal dominance. To address these challenges, my research focuses on how the physical structure and density of macroalgal stands shapes habitat use and foraging decisions of key herbivorous fish functional groups on degraded coral reefs in Singapore. First, I will present results from field-based studies examining macroalgal removal by herbivorous fishes, and how this ecological process changes over spatial and temporal scales on coral reefs in Singapore. Second, I will demonstrate how predation risk (i.e. fear effects) shapes the foraging behaviour of herbivorous fishes, how this varies with macroalgal density and fish group sizes, and how this can lead to varied consequences of macroalgal removal on coral reefs. Finally, I will discuss the implications of my research findings, how these results relate to coral reefs in Hong Kong, and the next steps of this research on other Indo-Pacific coral reefs.

Speaker Biography:

Dr. Andrew Bauman is an American coral reef ecologist, with over 15 years of experience working on coral reefs across the Indo-Pacific. His research combines field and experimental ecology to investigate large-scale ecological processes that structure coral reef ecosystems. Andrew received his PhD from the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Australia. Currently, he is a Senior Research Fellow at the National University of Singapore where he leads a research program examining coral-algal interactions, herbivory and phase-shifts on urbanized coral reefs.

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