Assessing loss of coral cover on the Great Barrier Reef: A response to Hughes et al. (2011)
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Hughes et al. (Coral Reefs, 2011, in press) challenge our interpretations of the changes in coral cover observed on the Great Barrier Reef (GBR) between 1986 and 2004 (Sweatman et al. in Coral Reefs 30:521–531, 2011). They question whether we can accurately assign all causes of coral loss; we contend that this makes no difference to the observed changes. They defend the validity of historical data on coral cover from before the start of systematic large-scale monitoring and conclude that coral cover has been declining since at least 1960, but we find no trend in the early data. We remain convinced that combining data collected at different spatial scales (quadrats and transects in the past mixed with more recent whole-reef averages from manta tows) are likely to overestimate decline, because whole-reef averages will very rarely reach the high cover values that can occur at the quadrat scale. Hughes et al. (Coral Reefs, 2011, in press) state that we dismiss runoff as a cause of ecosystem degradation; we defend our interpretations and dispute some of their examples. In summary, we stand by our conclusion that coral cover on the GBR declined in the period 1986–2004 but through localised and unsynchronised changes that included recovery.
KeywordsCoral cover Meta-analyses Great Barrier Reef Degradation
We thank L. Castell, A. Cheal, P. Doherty, M. Emslie, K. Johns, M. Jonker and I. Miller for comments on drafts of this manuscript.
- Ganter R (1987) Oral history of human use and experience of crown of thorns starfish on the Great Barrier Reef. Report to the Great Barrier Reef Marine Park Authority, TownsvilleGoogle Scholar
- Hughes TP, Bellwood DR, Baird AH, Brodie J, Bruno JF, Pandolfi JM (2011) Shifting base-lines, declining coral cover, and the erosion of reef resilience. Comment on Sweatman et al. (2011) Coral Reefs: in pressGoogle Scholar
- King B, McAllister F, Wolanski E, Done T, Spagnol S (2001) River plume dynamics in the central Great Barrier Reef. In: Wolanski E (ed) Oceanographic processes of coral reefs: physical and biological links in the Great Barrier Reef. CRC Press, Boca Raton, pp 145–160Google Scholar
- Miller I (2002) Historical patterns and current trends in the broadscale distribution of crown-of-thorns starfish in the northern and central sections of the Great Barrier Reef. Proc 10th Int Coral Reef Symp 2:1273–1279Google Scholar
- Wachenfeld D (1997) Long-term trends in the status of coral reef-flat benthos: the use of historical photographs. Proceedings of the State of the Great Barrier Reef World Heritage Area Workshop. Great Barrier Reef Marine Park Authority, Townsville, pp 134–148Google Scholar
- Wolanski E, Spagnol S (2000) Pollution by mud of Great Barrier Reef coastal waters. J Coast Res 16: 1151–1156Google Scholar