[Coral-List] Reassessing Coral Reef Scientists
Douglas Fenner
douglasfennertassi at gmail.com
Fri Apr 10 17:41:29 EDT 2015
Dennis,
I agree with much of what you say. I was very unspecific about what I
meant by reef flat, sorry. I was thinking of reef flats that are very
close to the lowest tide levels of the year. I agree that corals 2-3 m
deep can grow without being limited by exposure to air at low tides.
I was trying to make the point that on reef flats that shallow, any
corals that grow above the level of the lowest tides of the year will be
killed by exposure during those low tides. They can grow higher than that
the rest of the year, but will be killed by exposure to air by the lowest
tides. Low tides limit the growth of corals on reef flats, that is for
sure, corals die in air (though they can last for perhaps a few hours at
most in air).
The two papers I referred to document that when there are longer
periods without the lowest tides, coral cover increases on these shallow
reef flats. That makes sense to me, because when the lowest tide occur,
they kill corals that have grown too high. Most of us would see increased
coral cover as a good thing, and these two papers plus the observation of
low tides killing corals on the reef flat, indicate that sea level rise
will lead to increased live coral cover on shallow reef flats. Actually,
if the reef flats don't grow upward at all, the effect should be larger
than if the reef flats do grow upward, since the water will be deeper as
sea level rises, and thus there will be more room for corals to grow. That
might well lead to more coral cover on shallow reef flats than would be the
case if the reef flats grow upward. But the more live coral there is on
the reef flat, the faster the reef flat should be able to grow upward I
would think, since the corals are the fastest growing calcifiers on the
reef flat, the more corals the faster the reef flat would grow upward, I
would think. I don't know if that's been documented.
I don't know how many reefs will manage to keep up with sea level
rise. The article I read on reef growth rates, Montaggioni, 2005, says
that average growth of catch-up reefs is 3-4 mm a year, and the average
growth of keep-up reefs is 6 mm a year. Reefs with flats near the water
surface presently would be considered keep-up reefs I would think, and thus
reefs with shallow reef flats would be predicted to grow upward at an
average of 6 mm a year, twice the present rate of sea level rise. That is,
if Montaggioni's review of the evidence is correct. Those figures can't
apply to reef flats, or else during periods of stable sea level, the reef
flat would grow up into the air. Surely they apply only to reef areas
below low tide level. I believe that he says that there is considerable
variation between reefs in the rate that they grow, the 6 mm is only an
average. So a minority of keep-up reefs would grow at less than 3 mm a
year. Corals can clearly grow much faster than both sea level rise and the
average rate of growth of a reef. Staghorns can grow 100 mm or more a year
on their branch tips, massive Porites grow around 5-10 mm a year, but
encrusting corals probably add very little to their thickness in a year.
So it does make a big difference which kind of coral. If most corals on
reef flats can grow faster than present sea level rise, my guess is that
higher coral cover with deepening water will lead to a faster reef growth
rate. But if such an effect exists, I don't know how big it might be, I
don't know how much faster the reef flat could grow upward, though I'd
predict that would depend on how much coral cover there is, and how fast
that coral grows. Local human impacts are indeed likely to slow coral and
reef growth I would think, but there are lots of atolls with no people, and
the longest fringing reef in the world, Ningaloo Reef, on the west coast of
Australia, has almost no human impacts and the coast is a desert so little
if any runoff.
But my main point that rising sea levels will lead to more coral cover
on reef flats is supported by those two articles.
Coral growth is encouraged by water motion, up to the point at which
skeletons start to break. Most of the energy of a wave is dissipated where
the wave breaks, which is usually on the crest. Thus, reef flats receive
much less wave energy than the crest, and don't have the concussion from
the falling wave, which I've read is the strongest force breaking
skeletons. For reefs with coral on the crest, increasing wave action on
the reef flat should be good for corals, unless they are on unstable
substrate such as rubble. For reefs with only coralline algae on the
crest, it might be that waves on the reef flat will break corals during the
heaviest wave periods, such as during storms. So for those reefs, I don't
know what the net effect would be. Could be that deeper water would allow
more coral growth between storms, but storms would break the coral. But
for reefs with corals on the crest, increasing waves on the reef flat
should help coral growth there. Unless it is along a coast with lots of
terrestrial sediment, which a good number of reefs have, but other reefs
like atolls and Ningaloo Reef don't have.
Cheers, Doug
Montaggioni, L.F. 2005. History of Indo-Pacific coral reef systems since
the last glaciation: Development patterns and controlling factors.
Earth-Science Reviews 71: 1-75.
On Thu, Apr 9, 2015 at 1:45 AM, Dennis Hubbard <dennis.hubbard at oberlin.edu>
wrote:
> Hi Doug, Regarding your comments on SL rise, this conflates coral growth
> and reef building. The work of Peter Davies, David Hopley and others
> clearly showed that these reef flats broadened after reef caught up with
> slowed (actually stable or falling) sea level after 8 CalBP. The reefs
> built at their fastest rates after initial start-up, but it is unclear
> whether this was a response of faster sea-level rise or just the background
> accretion rate. In the Caribbean, it is clear that reefs in 20+ m of water
> build just as fast as those in 2-5 m of water. Our preliminary analyses of
> other data suggest that this is mimicked in other oceans. To me, the fact
> that the depth-related patterns of coral growth is not mirrored by reef
> building suggests that coral growth is a very poor proxy for what will
> happen as accelerating sea level opens up accommodation space atop reef
> flats. Very careful and thoughtful studies have shown that even 20 cm of
> freeboard atop the reef crest can more than double the wave energy normally
> filtered by the reef. Also, increased storm intensity will dramatically
> increase export from the ref proper (either across the reef flat in the GBS
> and the Indo-Pacific or down-slope in the Caribbean. Reef building is a
> complex process and coral growth, while providing the building blocks, is a
> very small part of the total budget. Existing data on reef building
> suggests that the present rate of sea-level rise is faster than the
> Holocene accretion rates of more than half of the reefs where coring has
> occurred (and this was with plenty of available accommodation space). Also,
> we must remember that this was at a time before *Homo stupidus* was
> providing the myriad stresses that are common today. To me, it is not
> comforting to realize that so many reefs are already lagginf behind is the
> most optimistic picture available.
>
> Best,
>
> Dennis
>
> On Wed, Apr 8, 2015 at 6:04 PM, Douglas Fenner <
> douglasfennertassi at gmail.com> wrote:
>
>> 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
>> comments.
>>
>> 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.
>>
>>
>> http://onlinelibrary.wiley.com/doi/10.1002/bies.201400074/abstract (not
>> open access, click on "author information" to get the author's email
>> address)
>>
>>
>> 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
>> respect to
>>
>> 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
>> change:
>>
>>
>> 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.
>>
>>
>>
>> Cheers, Doug
>>
>>
>>
>> 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>
>> wrote:
>>
>> > 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
>> > ---------------------------------- -----------------------------------
>> >
>>
>> 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:
>> >
>> http://phys.org/news/2012-02-coral-growth-western-australia-warmer.html#jCp
>> > -
>> >
>> >
>> > Abstract
>> >
>> >
>> > 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
>> > papers......
>> >
>> >
>> >
>> >
>> http://www.smh.com.au/federal-politics/political-news/fight-climate-change-by-building-away-from-sea-rupert-murdoch-20140713-zt66s.html#ixzz37oiOo25z
>> >
>> >
>> >
>> > 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
>> > Wilkpedia...
>> > >
>> > >
>> > > 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."[9] Its former editor Paul Kelly has stated that "The
>> > > Australian has established itself in the marketplace as a newspaper
>> > > that strongly supports economic libertarianism".[10]
>> > >
>> > > 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."[12]
>> > >
>> > >
>> > > On 8 Apr 2015, at 6:46 am, Eugene Shinn <eugeneshinn at mail.usf.edu>
>> > wrote:
>> > >
>> > >> 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
>> > >> ----------------------------------
>> > >> -----------------------------------
>> > >>
>> > >> _______________________________________________
>> > >> Coral-List mailing list
>> > >> Coral-List at coral.aoml.noaa.gov
>> > >> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>> > >
>> > > _______________________________________________
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>> >
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>> >
>>
>>
>>
>> --
>> Douglas Fenner
>> Contractor with Ocean Associates, Inc.
>> PO Box 7390
>> Pago Pago, American Samoa 96799 USA
>>
>> phone 1 684 622-7084
>>
>> "belief in climate change is optional, participation is not."
>>
>> Politics, science, and public attitudes: What we're learning, and why it
>> matters. Science Insider, open access.
>>
>>
>> http://news.sciencemag.org/social-sciences/2015/02/politics-science-and-public-attitudes-what-we-re-learning-and-why-it-matters?utm_campaign=email-news-latest&utm_src=email
>>
>> Homeopathy ineffective, study confirms.
>>
>>
>> http://news.sciencemag.org/sifter/2015/03/homeopathy-ineffective-study-confirms
>>
>> website: http://independent.academia.edu/DouglasFenner
>>
>> blog: http://ocean.si.edu/blog/reefs-american-samoa-story-hope
>> _______________________________________________
>> Coral-List mailing list
>> Coral-List at coral.aoml.noaa.gov
>> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>>
>
>
>
> --
> Dennis Hubbard
> Chair, Dept of Geology-Oberlin College Oberlin OH 44074
> (440) 775-8346
>
> * "When you get on the wrong train.... every stop is the wrong stop"*
> Benjamin Stein: "*Ludes, A Ballad of the Drug and the Dream*"
>
--
Douglas Fenner
Contractor with Ocean Associates, Inc.
PO Box 7390
Pago Pago, American Samoa 96799 USA
phone 1 684 622-7084
"belief in climate change is optional, participation is not."
Politics, science, and public attitudes: What we're learning, and why it
matters. Science Insider, open access.
http://news.sciencemag.org/social-sciences/2015/02/politics-science-and-public-attitudes-what-we-re-learning-and-why-it-matters?utm_campaign=email-news-latest&utm_src=email
Homeopathy ineffective, study confirms.
http://news.sciencemag.org/sifter/2015/03/homeopathy-ineffective-study-confirms
website: http://independent.academia.edu/DouglasFenner
blog: http://ocean.si.edu/blog/reefs-american-samoa-story-hope
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