Shaun was awarded a PhD from James Cook University in 2002. Supervised by David Bellwood, Shaun’s work determined detritus and detritivorous fish are important components of reef food webs, and challenged traditional ideas of trophodynamics on coral reefs. Between 2003 and 2004 Shaun taught marine ecology at the School for Field Studies and was based in the Caribbean nation, Turks and Caicos Islands. In 2005 he accepted a post-doctoral position at Newcastle University in the UK, working with Nick Polunin on the impact of habitat loss on coral reef fish communities. His recent work with colleagues at Newcastle, AIMS and JCU has focused on how loss of coral and associated reef structure interact with anthropogenic influences to affect fish assemblages.
ABSTRACT:
Overexploitation and habitat degradation are the two major drivers of global environmental change and are responsible for local extinctions and declining ecosystem services. Here we compare the top-down effect of exploitation by fishing to the bottom-up influence of habitat loss on fish communities in the most diverse of ecological systems, coral reefs. Using a combination of multivariate techniques and path analyses we illustrate that the relative importance of coral cover and fishing in controlling fish abundance on remote Fijian reefs varies between species and functional groups. Effects of both fishing and coral loss are stronger on individual species than functional groups, as variation in the relative importance of fishing or coral loss between species within the same functional group attenuated the impact of either of these potential drivers at the functional level. Fishing continues to have an influence on Fijian fish communities; however habitat loss is currently the overriding agent of change. The importance of coral loss mediated by climate change is expected to have an increasing contribution to fish community dynamics, particularly in remote locations or where the influence of fishing is waning.