Cvitanovic et al., 2007:

"The GBR exhibits considerable species richness at the herbivorous and nominally herbivorous trophic level. In low diversity systems, such as the Caribbean, minor changes in biodiversity can have dramatic impacts on the ecosystem. However, it is not necessarily safe to assume that the corollary is true. High species diversity, such as that displayed by the GBR, does not necessarily confer greater resilience and high diversity systems can still display limited functional redundancy (Bellwood et al 2003, Fox & Bellwood in press). An increased understanding of the functional role played by individual species of herbivore will be crucial if we are to make prescriptions for the prevention (and reversal) of phase shifts on coral reefs.

The focus of recent research on herbivory on the GBR has now shifted to view the process as one of a number of factors determining the resilience of coral reefs. This new focus has revealed some crucial gaps in our understanding of herbivory. We know much of what herbivores as a group do on reefs qualitatively speaking, but little about the individual functional components of the group and their quantitative effects. Viewed from the perspective of the overall reef system, however, it is precisely this quantitative understanding of ecosystem function that will provide the next insights into the process of herbivory on coral reefs.

The practical requirements of this new research agenda are considerable. It will require a fully integrated knowledge of the individual species: their ontogeny, their interactions with the substratum, their ability to consume and remove algae and their relationship to current distribution patterns of algae across the GBR. The predominant message emerging from recent studies is that the process of herbivory is a more subtle one than previously imagined and can show variation even at the scale of neighbouring reefs. Understanding herbivory on the GBR at the gross scale will not be enough to make predictions about individual systems. Estimates of existing abundances of herbivores and associated benthic algal communities should be extended to a more diverse collection of sites across the GBR and investigations of the process of herbivory should incorporate methods that allow us to witness feeding behaviour in the absence of divers."

---

Citation and/or URL

Cvitanovic, C., Fox, R.J. and Bellwood, D.R., 2007, 'Herbivory by fishes on the Great Barrier Reef: A review of knowledge and understanding'. Unpublished Report to the Marine and Tropical Sciences Research Facility. Reef and Rainforest Research Centre Limited, Cairns, 33 pp.

http://www.rrrc.org.au/publications/downloads/Project-25i3-Herbivory-Status--Trend-Report-June-2007.pdf

Spatial Coverage

Review report: reef-wide

Temporal Coverage

Review report

Update Frequency

 Not applicable

Other Information

None