Reef alarmists jump the shark

It is also worth noting that the estimated annual amount of nitrates and phosphates in runoff is about three times the amount used in agriculture after allowance is made for the amounts taken up by crops, oxidized into the atmosphere and bound up in insoluble form in the soil. In other words, even if the estimates are correct (which is doubtful) two-thirds or more would seem to actually derive from natural sources.

It is further worth noting that the high levels of nitrates and phosphates reported from river water occur in the dry season when the river flow almost ceases and the only runoff is from the forest covered headwaters, not the farmed areas lower down. When the rains come and farm runoff begins, the nutrient level falls steeply and is diluted much further when it reaches the sea. The modestly increased level off the river mouths is quickly taken up by plankton. It disappears within a few kilometres, and tens of kilometres from the reef itself.

On the other hand, natural nutrient fluxes from internal waves along the outer barrier regularly produce orders of magnitude greater nutrient increases than any runoff from land and no one is concerned about that. In fact, it's thought to be beneficial.

By far the most toxic, damaging and easy to demonstrate detriment to corals from runoff is the fresh water itself. Still another false statement is that,

Global warming is also increasing rainfall variability resulting in more frequent intense drought-breaking floods that carry particularly high nutrient and sediment loads.

Major Queensland floods were, in fact, far more frequent and intense in the 19^th century then they have been in the past century.

The claim is made that, "Reducing COTS (crown of thorns starfish) populations, by improving water quality and developing alternative control measures, could prevent further coral decline and improve the outlook for the Great Barrier Reef."

This is entirely supposition, and the actual result could well be the opposite. After nearly half a century and over a hundred million dollars in research, the COTS outbreaks are no better understood, nor are they any more of a threat, than they ever were. They continue to occur sporadically as they do with other starfishes and sea urchins in many other places. Such outbreaks also often occur on isolated oceanic reefs far from any runoff or human influence.

There is nothing to indicate the GBR outbreaks are due to anything other than natural causes. In fact they may even play a beneficial role in the maintenance of coral diversity as the starfish selectively prune the fast growing branching and plate-like species permitting the slower growing forms to catch up. This is especially noticeable a few years after severe storm damage, when the faster growing species tend to predominate and when COTS outbreaks are likely to occur.

The report concludes that, "…coral cover on the GBR is consistently declining, and without intervention, it will likely fall to 5–10% within the next 10 [years]."

Interestingly, this particular claim is conflicted by the most comprehensive previous study (published only three years earlier by the sane institution) which, "…found no evidence of consistent, system-wide decline in coral cover since 1995."

If the experts were wrong then is there any reason to think they are right now?