[Coral-List] Reassessing Coral Reef Scientists
douglasfennertassi at gmail.com
Wed Apr 8 18:04:56 EDT 2015
I didn't notice the date of the article, Feb. 2012, initially, it is in
such small, light print. This article is not recent news. Thanks to
everybody for pointing out the article it was based on, and the informative
My take on the Cooper 2012 Science article is that decreases in the
rate of calcification had been reported in a previous paper based on GBR
(Great Barrier Reef) data, and there had been speculation that it could
indicate that acidification had begun to slow coral growth. But the Cooper
paper found that on the west coast of Australia, calcification had
increased along with increasing temperatures, and increased most in the
south where temperatures were lower and the increase greater. So they
conclude that the dominant effect at this point is the effect of warming
temperatures, because increasing temperatures strongly increase the rate of
calcification (and linear extension, the main contributor to
calcification). They explain the GBR result as likely being due to the GBR
having reached higher temperatures at which growth may begin to slow, or
due to decreased growth there due to bleaching.
Articles have previously documented that massive *Porites* corals growth
rate increases with temperature. Such as in:
Lough, J.M. 2008. Coral calcification from skeletal records revisited.
Marine Ecology Progress Series 373: 257-264. Figure 2b shows skeletal
extension rate increasing with increasing temperature. Figure 2a shows
skeletal density decreasing with increasing temperature, and Figure 2c
shows calcification increasing with temperature. The range of annual
average sea temperature was 23-29.5 C.
http://www.int-res.com/abstracts/meps/v373/p257-264/ open access
People do tend to assume that all effects of climate change and global
warming will be negative. Not true, I would argue. For instance, melting
Arctic sea ice will make ship navigation there possible, with likely
economic benefits. It may also make drilling for oil in the Arctic ocean
easier, with all of the possible effects on economics and the environment.
Also, people often say that rising sea levels will hurt reefs. Indeed,
where there are soft terrestrial sediments, increased wave action due to
less friction with the substrate in the deeper water on reef flats will
mobilize sediment and negatively impact corals. But where there is no such
sediment, like on atolls, more water depth allows more coral growth on reef
flats. There are a lot of atolls, and reef flats around the world have
about 6 times the area of reef slopes, so that's not a minor consideration,
though sea level rise of 3 mm a year is way slower than most corals can
grow, so corals will likely hit the surface and be limited anyhow. Plus,
once mass coral bleaching kills them, they won't be growing any more. So a
temporary positive effect. References listed at the end of this message.
Another paper adds some perspective:
Wooldridge, S. A. 2014. Assessing coral health and resilience in a
warming ocean: why looks can be deceptive. BioEssays 36(11): 1041-1049.
open access, click on "author information" to get the author's email
He writes in the abstract, "In this paper I challenge the notion that a
healthy and resilient coral is (in all cases) a fast-growing coral, and by
inference, that a reef characterised by a fast trajectory toward high coral
cover is necessarily a healthy and resilient reef." and "Moreover, it
explains the somewhat
paradoxical scenario, whereby at the ecological instant before the
reef-building capacity of the symbiosis is lost, a reef can look visually
at its best and be accreting CaCO3 at its maximum."
In general, I believe it is the case with most poikilothermic or ectodermic
animals, that as temperature rises, metabolism increases, gradually and
reversibly, up to a point. Above that point, it decreases, precipitously
and irreversibly. Corals are no different. The two processes are quite
different, the precipitous drop at high temperatures is due to the
denaturing of proteins primarily, I would think, and it leads to death. In
other words, for any animal, indeed any organism, if the temperatures gets
too high, they get cooked and die.
So increasing temperatures seem great, but beyond a certain point are
lethal. The problem for corals is that in many places, they live close to
their upper thermal limit in the summer, and global temperatures are
increasing. In places where they live well below their thermal maximum,
temperature increases may not be a threat, and increase growth rates, which
seems good. Mind you, much of the threat doesn't come directly from
gradually increasing temperatures, it comes from hot water events, such as
the 1998 El Nino event that killed about 16% of the world's corals. Such
events can push even corals in cooler water over their limits, since their
limits tend to be lower, usually just a couple degrees above the local mean
summer high temperature. Janice Lough tells me that the corals on the west
coast of Australia bleached in 2011, 1-2 years after they collected their
coral cores. The high temperature of El Nino events and the like, are on
top of the gradually warming baseline, so as the baseline goes up, the peak
event temperatures go up as well (though they vary greatly depending on the
strength of the El Nino) and thus likely the damage. If I remember, the
maps of where coral bleaching on the GBR occurred in the major events of
1998 and 2002, didn't show that they only bleached at the northern end,
they bleached at the southern end too (where average water temperatures are
lower). In fact, they bleached more at the southern end than the northern
end, judging from Fig. 2 in the following article:
Berkelmans, R., De’ath, G., Kininmonth, S. & Skirving,W. J. 2004 A
comparison of the 1998 and 2002 coral bleaching events on the Great Barrier
Reef: spatial correlation, patterns and predictions. Coral Reefs 23, 74–83.
The Cooper paper says in the next to last paragraph that "The
influence of ocean acidification is expected to occur first at higher
latitudes that inherently have lower seawater saturation states with
carbonate minerals due to their increased solubility at lower water
temperatures (10, 30)."
The following paper predicts that while bleaching will degrade corals in
the future mainly at low latitudes, acidification will degrade them at high
latitudes, and so there is no latitude that offers a refuge from climate
van Hooidonk R, Maynard JA, Manzello D, Planes S (2014) Opposite
latitudinal gradients in projected ocean acidification and bleaching
impacts on coral reefs. Global Change Biology, 20, 103–112.
http://onlinelibrary.wiley.com/doi/10.1111/gcb.12394/abstract Not open
access, but click on author information for the author's email address.
Fenner, D. 2012. Reef flat growth: comment on “Rising sea level may cause
decline of fringing coral reefs.” EOS 93 (23): 218.
Brown, B. E., R. P. Dunne, N. Phongsuwan, and P. J. Somerfield (2011),
Increased sea level promotes coral cover on shallow reef flats in the
Andaman Sea, eastern Indian Ocean, Coral Reefs, 30, 867–878.
Scopélitis, J., S. Andréfouët, S. Phinn, T. Done, and P. Chabanet (2011),
Coral colonization of a shallow reef flat in response to rising sea level:
Quantification from 35 years of remote sensing data at Heron Island,
Australia, Coral Reefs, 30, 951–965.
Vecsei, A. 2004. A new estimate of global reefal carbonate production
including the fore-reefs. Global and Planetary Change 43:1-18.
On Tue, Apr 7, 2015 at 9:46 AM, Eugene Shinn <eugeneshinn at mail.usf.edu>
> Listers, Here is a report of work done by coral scientists in Australia
> readers might want to reassess. Gene
> No Rocks, No Water, No Ecosystem (EAS)
> ------------------------------------ -----------------------------------
> E. A. Shinn, Courtesy Professor
> University of South Florida
> College of Marine Science Room 221A
> 140 Seventh Avenue South
> St. Petersburg, FL 33701
> <eugeneshinn at mail.usf.edu>
> Tel 727 553-1158
> ---------------------------------- -----------------------------------
On Wed, Apr 8, 2015 at 6:23 AM, Greg Challenger <
GChallenger at polarisappliedsciences.com> wrote:
> Below is a link to the paper. I don't believe there is any longer any
> doubt that media outlets have agendas on all sides.
> The researchers found both decreases and increases in Porites growth with
> no widespread pattern. They did find contradictory evidence of increasing
> growth in higher latitudes. I didn't get into the power or significance.
> It is not shocking to learn that ranges can change as a result of physical
> forcing, even if contradictory. The study involves one size class of a
> single species (Porites) and doesn't speak to diversity as far as can be
> discerned from the abstract. As always, there are likely winners and
> losers when it comes to change. It doesn't surprise me that massive
> Porites lobata may be doing well because we find it in the most polluted of
> industrial harbors doing quite well throughout the Indo-Pacific and Red
> Sea. There was an in situ test (accident) that I cannot mention that
> removed oxygen from a certain harbor for a number of days and many members
> of this species survived while some others did not.
> One of the better Elkhorn Stands I have seen in recent years in the
> Caribbean was recently removed from the entrance of Kingston Harbor to make
> way for Post Panamex Vessels in some of the dirtier water I care to swim
> in, while some of the most recently devastated elkhorn I have seen was 100
> miles offshore in the Silver Banks, D.R., both within the past few years.
> I'm not sure we've got our fingers on the pulse of this thing, which
> makes it more challenging to convey a sense of urgency to the public. I
> usually ask for examples of positive ecological outcomes from unintended
> consequences of man and then I might worry less. I'm still waiting for
> some of those examples.
> Growth of Western Australian Corals in the Anthropocene, Science 3
> February 2012: Vol. 335 no. 6068 pp. 593-596. DOI: 10.1126/science.1214570
> Read more at:
> Anthropogenic increases of atmospheric carbon dioxide lead to warmer sea
> surface temperatures and altered ocean chemistry. Experimental evidence
> suggests that coral calcification decreases as aragonite saturation drops
> but increases as temperatures rise toward thresholds optimal for coral
> growth. In situ studies have documented alarming recent declines in
> calcification rates on several tropical coral reef ecosystems. We show
> there is no widespread pattern of consistent decline in calcification rates
> of massive Porites during the 20th century on reefs spanning an 11°
> latitudinal range in the southeast Indian Ocean off Western Australia.
> Increasing calcification rates on the high-latitude reefs contrast with the
> downward trajectory reported for corals on Australia's Great Barrier Reef
> and provide additional evidence that recent changes in coral calcification
> are responses to temperature rather than ocean acidification.
> ----Original Message-----
> From: coral-list-bounces at coral.aoml.noaa.gov [mailto:
> coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Tim
> Sent: Wednesday, April 8, 2015 7:49 AM
> To: Eugene Shinn
> Cc: <coral-list at coral.aoml.noaa.gov> list
> Subject: Re: [Coral-List] Reassessing Coral Reef Scientists
> .......more on "The Australian" newspaper.....
> Instead of engaging their vast resources to help finance genuine marine
> research, and using some of their influence to drive corporate
> accountability, particularly in "developing" economies, the paper
> specialises in selective editing of scientific papers and peddling their
> own business agenda.
> Some of us familiar with the Maldives, take exception to News Corp
> chairman Rupert Murdoch's disheartening comments at the newspaper's 50th
> anniversary last year.
> He said climate change should be treated with "much scepticism".
> If the temperature rises 3 degrees in 100 years, "at the very most one of
> those [degrees] would be man-made," he said.
> "If the sea level rises six inches, that's a big deal in the world, the
> Maldives might disappear or something, but OK, we can't mitigate that, we
> can't stop it, we have to stop building vast houses on seashores".
> Perhaps we should all give up, like drowned reefs, on reading his
> On 8 Apr 2015, at 16:31, Osmar Luiz wrote:
> > For those who were not familiar with "The Australian" newspaper points
> of view and its strong right-wing trend, some quotes below from The
> > According to other commentators, however, the newspaper "is generally
> > conservative in tone and heavily oriented toward business; it has a
> > range of columnists of varying political persuasions but mostly to the
> > right." Its former editor Paul Kelly has stated that "The
> > Australian has established itself in the marketplace as a newspaper
> > that strongly supports economic libertarianism".
> > In September 2010, the ABC's Media Watch presenter Paul Barry, accused
> > The Australian of waging a campaign against the Australian Greens, and
> > the Green's federal leader Bob Brown wrote that The Australian has
> > "stepped out of the fourth estate by seeing itself as a determinant of
> > democracy in Australia". In response, The Australian opined that
> > "Greens leader Bob Brown has accused The Australian of trying to wreck
> > the alliance between the Greens and Labor. We wear Senator Brown's
> > criticism with pride. We believe he and his Green colleagues are
> > hypocrites; that they are bad for the nation; and that they should be
> > destroyed at the ballot box."
> > On 8 Apr 2015, at 6:46 am, Eugene Shinn <eugeneshinn at mail.usf.edu>
> >> Listers, Here is a report of work done by coral scientists in
> >> Australia readers might want to reassess. Gene
> >> http://www.theaustralian.com.au/news/health-science/study-finds-coral
> >> -reef-growth-thrives-in-warmer-waters/story-e6frg8y6-1226261278615
> >> --
> >> No Rocks, No Water, No Ecosystem (EAS)
> >> ------------------------------------
> >> -----------------------------------
> >> E. A. Shinn, Courtesy Professor
> >> University of South Florida
> >> College of Marine Science Room 221A
> >> 140 Seventh Avenue South
> >> St. Petersburg, FL 33701
> >> <eugeneshinn at mail.usf.edu>
> >> Tel 727 553-1158
> >> ----------------------------------
> >> -----------------------------------
> >> _______________________________________________
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