Volume 7, Number 40: 6 October 2004
In our Editorial of 29 Sep 2004, we describe the study of Pandolfi et al. (2003a), wherein that group of twelve marine biologists demonstrates that 14 coral reefs from various parts of the world have already traveled nearly 30-80% of the way from what they call pristine to ecologically extinct. Noting that this trip of degradation began "centuries ago," when the earth was still in the midst of the Little Ice Age, they correctly state that its primary cause has been something quite different from the high-temperature-induced bleaching that is currently, in their words, "distract[ing] attention from the chronic and severe historical decline of reef ecosystems," which distraction cannot help but confuse people about where to focus their time, money and efforts in the campaign to save earth's corals from what surely awaits them at the end of the road-to-extinction trip upon which someone or something has placed them.
Strangely, another group of coral researchers (Aronson et al., 2003) have had some problems with the study of Pandolfi et al., claiming that coral reefs in many parts of the world did not begin to suffer to any significant degree "until recent decades," and questioning their hypothesis that prior overfishing has been the leading cause of long-term reef degradation. In response to this challenge, Pandolfi et al. (2003b) remain unmoved from their original position, as the following series of quotes from their rebuttal clearly demonstrates.
"Coral reef ecosystems were degraded long before more recent changes attributable to climate change or disease" ? "recent changes represent an ongoing degradation that long predates modern ecological studies" ? "Although we agree that bleaching and disease are becoming more prevalent, the ability of reefs to absorb these impacts will clearly depend on the extent to which they are already degraded" ? "so-called proximal causes [bleaching and disease] are not the ones that have acted over long time periods or that have caused the most intense degradation of reefs and associated ecosystems" ? "the ultimate causes of coral reef ecosystem decline are more subtle than recent proximal ones and reach further back in time than events observed in the past few decades."
What would a qualified third party have to say about this debate? Fortunately, one has weighed in on the issue; and it is a group to whom Aronson et al. actually appealed in their critique of Pandolfi et al. (2003a), when they said that a review by Hughes et al. (2003) "concludes that climate change and disease are the primary agents of increased coral mortality and that degraded reefs will survive, albeit with altered species composition."
Normally, one would not think that such a brief remark, which does not question the findings of the third party and actually cites them approvingly, would elicit a response from them. Nevertheless, the third group of 16 marine biologists, 13 of whom were not involved in the study of Pandolfi et al., took it upon themselves to respond to Aronson et al. in language that clearly supports the original group's thesis.
"We focused more on contemporary threats and future solutions" ? "Human impacts and the increased fragmentation of coral reef habitat have undermined reef resilience, making them much more susceptible to current and future climate change" ? "In particular, we presented clear, unambiguous evidence that overharvesting of herbivorous fishes can impair the resilience of coral reefs and inhibit their recovery from bleaching and other disturbances" ? "We do not consider our findings to be in conflict with those of Pandolfi et al."
In light of this further discussion of the causes of both long- and shorter-term coral reef degradation, we continue to hold to our belief that to save earth's fast-fading coral reef ecosystems we must focus our attention on alleviating the many direct effects of human activities that have (1) negatively affected them in the past, (2) continue to plague them in the present, and (3) will destroy them in the not too distant future, unless we act soon and properly. To believe that we will save these incomparable ecosystems by implementing the almost totally ineffective Kyoto Protocol, or anything like it, is simply wishful thinking ? or worse! For the resulting neglect of the real problem, about which we actually can do something, is to allow earth's coral reefs to continue unimpeded down the road to extinction, which most reefs have already halfway traversed and from whence there is no hope of their ever returning.
|Sherwood, Keith and Craig Idso|
Aronson, R.B., Bruno, J.F., Precht, W.F., Glynn, P.W., Harvell, C.D., Kaufman, L., Rogers, C.S., Shinn, E.A. and Valentine, J.F. 2003. Causes of coral reef degradation. Science 302: 1502.
Hughes, T.P., Baird, A.H., Bellwood, D.R., Connolly, S.R., Folke, C., Grosberg, R., Hoegh-Guldberg, O., Jackson, J.B.C., Kleypas, J., Lough, J.M., Marshall, P., Nystrom, M., Palumbi, S.R., Pandolfi, J.M., Rosen, B. and Roughgarden, J. 2003. Response. Science 302: 1503.
Pandolfi, J.M., Bradbury, R.H., Sala, E., Hughes, T.P., Bjorndal, K.A., Cooke, R.G., McArdle, D., McClenachan, L., Newman, M.J.H., Paredes, G., Warner, R.R. and Jackson, J.B.C. 2003a. Global trajectories of the long-term decline of coral reef ecosystems. Science 301: 955-958.
Pandolfi, J.M., Bradbury, R.H., Sala, E., Hughes, T.P., Bjorndal, K.A., Cooke, R.G., McArdle, D., McClenachan, L., Newman, M.J.H., Paredes, G., Warner, R.R. and Jackson, J.B.C. 2003b. Response. Science 302: 1502-1503.