What Is the Greatest Threat to Australia's Great Barrier Reef?
Bell, P.R.F., Elmetri, I. and Lapointe, B.E. 2014. Evidence of large-scale chronic eutrophication in the Great Barrier Reef: Quantification of chlorophyll a thresholds for sustaining coral reef communities. Ambio 43: 361-376.
In further discussion of the subject, Bell et al. write "it is now widely accepted that the lack of recovery of the reefs and the proliferation of COTS are largely attributable to eutrophication," while also reporting "evidence is emerging that CSDs and coral bleaching are also promoted by eutrophication," much of which is due to "increased loads of nutrients exported via discharges from coastal developments."
Taken together, these findings suggest that it is local water pollution that is the primary instigating force that has led to the destruction of nearly three-quarters of the GBR's corals over the past century. The historical increase in the atmosphere's CO2 concentration has had next to nothing to do with it.
Boyett, H.V. 2006. The ecology and microbiology of black band disease and brown band syndrome on the Great Barrier Reef. MSc Thesis. James Cook University, Townsville, Australia.
Haapkyla, J., Unsworth, R.K.F., Flavell, M. , Bourne, D.G., Schaffelke, B. and Willis, B.L. 2011. Seasonal rainfall and runoff promote coral disease on an inshore reef. PLOS ONE 6: e16893.
Willis, B.L., Page, C.A. and Dinsdale, E.A. 2004. Coral disease on the Great Barrier Reef. In: Rosenberg, E. and Loya, Y. (Eds.). Coral Health and Disease, Springer, Berlin, Germany, pp. 69-104.