ABSTRACT:

The trophic link between corals and fishes is potentially very important in energetics of coral reef ecosystems. Corallivory is the primary means of incorporating energy derived from corals into higher trophic levels. However, chronic grazing by fishes must also represent a significant energetic cost for reef-building corals. Natural stressors like coral predation will likely be compounded by the effects of climate change and other anthropogenic stressors. This interaction is not yet understood, and further study is required for the appropriate management of coral reefs. The primary aim of this research project is to explore the energetic cost of chronic fish predation on common reef corals. I intend to do this through five research objectives: (1) compare the predation intensity on different coral species in different habitats; (2) quantify the amount of coral material which is removed by coral-feeding butterflyfish; (3) Compare coral energetics such as growth, condition and reproductive output in the presence and absence of chronic fish predation; (4) test the impact that newly settled obligate coral feeders have on the corals they inhabit; and (5) investigate possible beneficial aspects of fish predation by testing whether coral predators consume coral disease and whether this consumption slows the rate of progression of these diseases. The combination of these aims will greatly increase the understanding of the functional importance and ecological consequences of corallivory on coral reefs and allow me to investigate whether corallivores are exacerbating changes to coral reef dynamics resulting from global environmental change.