Benthic community composition influences within-habitat variation in macroalgal browsing on the Great Barrier Reef
C. Cvitanovic A B and A. S. Hoey AA Australian Research Council Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.
B Corresponding author. Email: christopher.cvitanovic@environment.gov.au
Marine and Freshwater Research 61(9) 999-1005 https://doi.org/10.1071/MF09168
Submitted: 5 July 2009 Accepted: 17 February 2010 Published: 23 September 2010
Abstract
The removal of macroalgae by herbivores is fundamental to the long-term persistence of coral reefs. Variation in macroalgal browsing has been documented across a range of spatial scales on coral reefs; however, few studies have examined the factors that influence within-habitat rates of herbivory. The aim of the present study was to quantify herbivory on two species of Sargassum across three bays on an inshore island in the central Great Barrier Reef (GBR), and to determine whether these removal rates were related to the benthic composition or herbivorous fish communities. Removal rates of Sargassum differed significantly among bays, with removal rates in the southern bay (66.9–83.0% per 3 h) being approximately double that of the two other bays (29.2–38.5% per 3 h). The removal rates displayed a direct relationship with the benthic community structure, in particular the cover of macroalgae and live plate corals. Although it is difficult to determine whether these relationships are related to the availability of food resources or the structural complexity of the substratum, they highlight the potential influence of benthic composition on ecological processes. Quantifying and understanding the drivers of herbivory across a range of spatial scales is essential to the future management of coral reefs.
Additional keywords: benthic composition, coral reefs, herbivory, macroalgal assay, resilience, spatial variation.
Acknowledgements
We thank D. Bellwood for his guidance and support throughout this study; C. Ryen, D. Coker, R. Bonaldo, J. Johansen and T. Mannering for invaluable field assistance; the staff of Orpheus Island Research Station for logistical support; and L. McCook and G. Diaz-Pulido for assistance with algal identification. Comments by R. Bonaldo, J. Johansen, K. Cvitanovic, A. Boulton and two anonymous reviewers greatly improved the manuscript. Financial support was provided by the Australian Research Council and the Marine and Tropical Sciences Research Facility, Reef and Rainforest Research Centre. This research was conducted under the Great Barrier Reef Marine Park Authority permit G07/23636.1.
Alcoverro, T. , and Mariani, S. (2004). Patterns of fish and sea urchin grazing on tropical Indo-Pacific seagrass beds. Ecography 27, 361–365.
| Crossref | GoogleScholarGoogle Scholar |
Levin, S. A. (1992). The problem of pattern and scale in ecology. Ecology 73, 1943–1967.
| Crossref | GoogleScholarGoogle Scholar |
Lewis, S. M. (1986). The role of herbivorous fishes in the organization on a Caribbean reef community. Ecological Monographs 56, 183–200.
| Crossref | GoogleScholarGoogle Scholar |
Lewis, S. M. , and Wainwright, P. C. (1985). Herbivore abundance and grazing intensity on a Caribbean coral reef. Journal of Experimental Marine Biology and Ecology 87, 215–228.
| Crossref | GoogleScholarGoogle Scholar |
MacNeil, M. A. , Graham, N. A. J. , Polunin, N. V. C. , Kulbicki, M. , and Galzin, R. , et al. (2009). Hierarchial drivers of reef-fish metacommunity structure. Ecology 90, 252–264.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
McClanahan, T. R. , McField, M. , Huitric, M. , Bergman, K. , and Sala, E. , et al. (2001). Responses of algae, coral and fish to the reduction of macroalgae in fished and unfished patch reefs of Glovers Reef Atoll, Belize. Coral Reefs 19, 367–379.
| Crossref | GoogleScholarGoogle Scholar |
McCook, L. J. (1996). Effects of herbivores and water quality on Sargassum distribution on the central Great Barrier Reef: cross-shelf transplants. Marine Ecology Progress Series 139, 179–192.
| Crossref | GoogleScholarGoogle Scholar |
Meyer, C. , and Holland, K. (2005). Movement patterns, home range size and habitat utilization of the bluespine unicornfish, Naso unicornis (Acanthuridae) in a Hawaiian marine reserve. Environmental Biology of Fishes 73, 201–210.
| Crossref | GoogleScholarGoogle Scholar |
Pratchett, M. S. , and Berumen, M. L. (2008). Interspecific variation in the distribution and diets of coral reef butterflyfishes (Teleostei: Chaetodontidae). Journal of Fish Biology 73, 1730–1747.
| Crossref | GoogleScholarGoogle Scholar |
Russ, G. R. (2003). Grazer biomass correlates more strongly with production than with biomass of algal turfs on a coral reef. Coral Reefs 22, 63–67.
Sluka, R. D. , and Miller, M. W. (2001). Herbivorous fish assemblages and herbivory pressure on Laamu Atoll, Republic of Maldives. Coral Reefs 20, 255–262.
| Crossref | GoogleScholarGoogle Scholar |
Steneck, R. S. (1988). Herbivory on coral reefs: a synthesis. Proceedings of the Sixth International Coral Reef Symposium 1, 37–49.
Wilson, S. K. , Graham, N. A. J. , Pratchett, M. S. , Jones, G. P. , and Polunin, N. V. C. (2006). Multiple disturbances and the global degradation of coral reefs: are reef fishes at risk or resilient? Global Change Biology 12, 2220–2234.
| Crossref | GoogleScholarGoogle Scholar |
Wismer, S. , Hoey, A. S. , and Bellwood, D. R. (2009). Cross-shelf benthic community structure on the Great Barrier Reef: relationships between macroalgal cover and herbivore biomass. Marine Ecology Progress Series 376, 45–54.
| Crossref | GoogleScholarGoogle Scholar |
