[cogitator]

While I agree that coral reefs are under stress, particularly from fishing practices, I have my problems with the tone of this report. First, coral reefs go through periodic dieoffs under natural conditions, some of which are far more devastating than anything precipitated by humans. Second, I doubt that they can even define what constitutes "pristine." Third, by what criteria are these assessments of risk made? I seriously doubt that we know so much about the function and behavior of coral reefs to be making such blanket statements.

There are some fairly obvious problems, the most important of which is excess nutrients in the waters where coral reefs are found. The source of these excess nutrients is from inadequate sewage and agricultural runoff, primarily. Some areas also have increasing turbidity due to increased erosion of coastal sediments. There's no doubt that coral needs clear and low-nutrient water to "prosper". Would you dispute that nutrient concentrations and turbidity have increased in many coastal regions? I sure hope not. In my reply to another poster in this thread, I also linked to an excellent article that tied white-band disease in the Keys, responsible for nearly eradicating elkhorn coral, to human waste. Is that a "natural" die-off?

It stinks of politics. Can you tell me who funded this research?

Apparently there was a variety of funding sources, based on the variety of author affiliations:

Department of Paleobiology, MRC-121, National Museum of Natural History, Post Office Box 37012, Smithsonian Institution, Washington, DC 20013–7012, USA.

Centre for Resource and Environmental Studies, Australian National University, Canberra, ACT 0200, Australia.

Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, La Jolla, CA 92093, USA.

Centre for Coral Reef Biodiversity, School of Marine Biology, James Cook University, Townsville, QLD 4811, Australia.

Archie Carr Center for Sea Turtle Research, Department of Zoology, Post Office Box 118525, University of Florida, Gainesville, FL 32611, USA.

Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 2072, Balboa, Republic of Panama.

California Sea Grant, University of California Cooperative Extension, Santa Barbara, CA 93105, USA.

Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA.

Sea Grant is NOAA; I'd suspect CSIRO for the Australian authors, and the usual suspects (NSF) for the American academic sites; obviously the Smithsonian gets its funding from the U.S. government.

[Carry_Okie]

The source of these excess nutrients is from inadequate sewage and agricultural runoff, primarily.

Given that cities used to dump raw sewerage into rivers and bays, I would not be persuaded that ag runoff is the cause without significant amounts of data.

Some areas also have increasing turbidity due to increased erosion of coastal sediments.

Here again, what were the background measurements upon which these claims are founded? Is it really worse now than for example in the 60's when dredging in bays and dumping operations at sea without any environmental review or mitigation were commonplace? How about the oil spills and maritime dumping that were then more frequent?

Im my study of nitrates in the San Lorenzo watershed, I found that the quality of such measurements that started in the 50's were horrible until about 1985 when the County bought more accurate equipment. Even now their measurements are subject to gross, single sided errors. That's a river in a populated area. Now, consider our measurements in the oceans. Do you really think that they had a good temporal and spatial picture back then of nutrient levels that accounted for seasonal variations and singularities (floods and hurricanes) from which to construct a baseline? I honestly doubt it.

Would you dispute that nutrient concentrations and turbidity have increased in many coastal regions?

I don't know for a fact, but from what I've seen of the West Coast, nutrient levels appear to me to have gradually fallen until very recently. In the last decade or so the recolonization of the coast to the point of overpopulation by seals and sea lions has led to a big jump in both nitrate and fecal coliform levels, especially south of Ano Nuevo.

I also linked to an excellent article that tied white-band disease in the Keys, responsible for nearly eradicating elkhorn coral, to human waste.

I'd have to read it. It sounds plausible at first, but I've seen so many frauds in this kind of work as to be more skeptical, particularly when it comes to attribution of causes. An example is the afore mentioned nitrate pollution from pinnipeds. The authorities assume that that contribution constitutes "natural" while anything over and above that is "pollution" simply because of their bias. They NEVER question whether the animals are getting overpopulated, even though there are few natural controls on their population (shark numbers are down and grizzlies are decidedly unpopular on public beaches). The harbor seals are floating up on the beaches from contagion.

I'd like to know how these scientists have determined the relative mass balance contribution of nutrient from all sources, especially considering how the system consumes that nutrient in rates that vary by history of location, temperature, predation, and seasonal disturbances. The work I've seen on that front so far looks pretty sketchy.

In response to another of your comments, both temperature and sea level changes have accounted for historic coral die-offs. I don't know about the impact of hurricanes.