DUST, REEFS, SENSATIONALISM

[Jack, Sobel]

Working for a conservation organization, I have on occasion heard members 
of both the scientific and press communities unfairly attack the 
conservation community for being too sensational and speculative.  Recent 
press reports on African Dust and Coral Disease Epidemics make me wonder 
whether if the shoe doesn't belong on the other foot these days, but it 
is not entirely clear whether this is a result of poor science, poor 
reporting, or both.

In press reports, statements by reputable scientists linking African Dust 
deposition and Coral Disease epidemics to major Pan-Caribbean and Florida 
Keys coral reefs declines; linking African Dust to coral disease 
epidemics; and linking the coral disease epidemics to Florida Bay and/or 
sewage discharge have been widely circulated.  Yet, there appears to be 
at best tenuous correlations and creative speculation behind these 
reports.  Such creativity and speculation can serve a valid purpose in 
the scientific (and public) process, but when sensationalized in press 
reports to garner funding, engage in dangerous experiments, affect 
policy, or deflect attention from well-documented problems such as 
over-harvesting and declining water quality can be quite destructive.

My questions to the coral-list serve community are:
(1)  What is the scientific evidence behind the African Dust scenario 
being a major contributor to Pan-Caribbean and Florida coral reef 
declines and how does this compare to evidence for the contributions of 
water quality degradation and overfishing?
(2)  What is the proposed mechanism for African Dust causing algal 
overgrowth or coral disease epidemics and what evidence is there to 
support them?
(3)  In high nutrient Southern Ocean waters far from continental/island 
run-off, iron has been suggested as a limiting factor in algal 
productivity. There is both a reasonable mechanism and some evidence to 
support this view. However, in low nutrient tropical environments 
adjacent to land, where coral reefs are found, is there any reason to 
believe that dust-born iron inputs from Africa are an important factor in 
shifting Coral/Algal balance relative to other factors?  Enough to fund 
or engage in the kind of speculative experimentation that has been 
proposed to dump iron into pristine coral reef communities and monitor 
the impact?

I'm interested in hearing any feedback, views, or information on these 
issues that other in the scientific community can provide?
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* Jack Sobel, Director                                             *
* Ecosystem Protection                                             *
* Center for Marine Conservation                                   *
* 1725 DeSales St. NW Suite #600                                   *
* Washington, DC 20036                                             *
* Phone:  (202)429-5609                                            *
* Fax     (202)872-0619                                            *
* Email:  jsobel at cenmarine.com                                     *
*                                                                  *
*                                                                  *
*"If the biota, in the course of aeons, has built something we like*
*but do not understand, then who but a fool would disgard seemingly*
*useless parts? To keep every cog and wheel is the first precaution*
*of intelligent tinkering."  Aldo Leopold                          *
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