Coral Reef Degradation: Anthropogenic-Induced or Natural?
Perry, C.T. and Smithers, S.G. 2011. Cycles of coral reef 'turn-on', rapid growth and 'turn-off' over the past 8500 years: a context for understanding modern ecological states and trajectories. Global Change Biology 17: 76-86.
However, as they continue, "most assessments of changing reef condition fail to consider the additional, but potentially significant, underlying influence a reef's age and evolutionary state exert on its contemporary ecological status and accretionary potential." Hence, they go on to "examine regional histories of mid- to late-Holocene reef establishment and growth to provide a longer-term context for interpretations of contemporary reef geomorphic and ecological states and trajectories," utilizing "reef chronostratigraphic data from the terrigenous sediment-dominated inner-shelf of the Great Barrier Reef, Australia, as a case site," which they say "is arguably the only region globally where sufficient reef accretion data exist to examine these issues at appropriate spatial scales."
The result of this undertaking, as they describe it, was their finding that even throughout the late Holocene, "reef health and growth has fluctuated through cycles independent of anthropogenic forcing." Thus, they concluded -- and rightly so -- that "degraded reef states cannot de facto be considered to automatically reflect increased anthropogenic stress," noting that "in many cases degraded or non-accreting reef communities may reflect past reef growth histories as much as contemporary environmental change."
Hoegh-Guldberg, O., Mumby, P.J., Hooten, A.J., Steneck, R.S., Greenfield, P., Gomez, E., Harvell, C.D., Sale, P.F., Edwards, A.J., Caldeira, K., Knowlton, N, Eakin, C.M., Iglesias-Prieto, R., Muthiga, N., Bradbury, R.H., Dubi, A. and Hatziolos, M.E. 2007. Coral reefs under rapid climate change and ocean acidification. Science 318: 1737-1742.
Veron, J.E.N., Hoegh-Guldberg, O., Lenton, T.M., Lough, J.M. and Obura, D.O. 2009. The coral reef crisis: the critical importance of <350 ppm CO2. Marine Pollution Bulletin 58: 1428-1436.