[Coral-List] SPAM R2: coral reefs and climate change: new article
Douglas Fenner
douglasfennertassi at gmail.com
Wed Nov 18 06:18:11 UTC 2015
Indeed we know that bleaching temperatures are not an absolute. That
is why the local bleaching threshold is estimated as about 1 degree C above
the local mean summer high water temperature, which varies a great deal
from location to location. That is one of the keys to the success of the
NOAA Coral Watch bleaching predictions. And it is important how long the
high temperatures last as well, thus the best predictor is actually in
"degree heating weeks."
Bleaching, of course can be produced by many things, such as high
temperatures, low temperatures, fresh water, extended dark, disease, etc.,
things which seem to stress the coral. But most or almost all mass coral
bleaching events now are during periods of high water temperatures.
Usually the cause of mass coral bleaching is pretty obvious, the water is
unusually hot, or unusually cold, or there is a big fresh water runoff,
etc. Bleaching also differs between genera of corals, species of corals,
individual corals, and even parts of corals (usually more on the upper
surface than lower surfaces). The latter is likely due to a contribution
from high light levels. Which is why I coined the term "photothermal
bleaching" to distinguish this type of bleaching from loss of zooxanthellae
from disease or other stresses, and to remind us that light plays a role in
mass coral bleaching as well as high temperatures. Reduced water motion
can also contribute.
Cheers, Doug
Fenner, D., and S. Heron. 2009. Annual summer mass bleaching of a
multi-species coral community in American Samoa. Proceedings of the 11th
International Coral Reef Symposium, Ft. Lauderdale. 1289-1293.
http://www.nova.edu/ncri/11icrs/proceedings/files/m25-04.pdf#zoom=100
On Mon, Nov 16, 2015 at 6:20 AM, Dennis Hubbard <dennis.hubbard at oberlin.edu>
wrote:
> Hi Julian:
>
> The scenario that you propose could very well be the case. However, the
> caveat is that weather and climate are very different.It does matter where
> in a year temperature changes, what the rate of change is and how long it's
> been at a particular temperature. Also, we know that "bleaching
> temperature" is not an absolute (Easter Island corals bleached at 19°;
> Caribbean corals bleach at lower temperatures than many in the Coral
> Triangle). So, as with calcification (calcification is not equal to coral
> growth rate which is not the same as reef building), we have to be very
> careful to think about scale and context. Having said this, you are in good
> company.... and your data are valuable as they represent a time series
> based on, as you correctly state, a common instrument. We will be
> organizing a session at the reef meeting next summer to discuss just these
> points.... and what we should be measuring.
>
> Dennis
>
> On Fri, Nov 13, 2015 at 11:34 PM, Julian <julian at reefcheck.org.my> wrote:
>
>> In reference to Doug's article, this is an unscientific personal
>> observation, but related. I lived on Tioman island, off Malaysia's east
>> coast for six years running a dive centre, diving at least twice a day for
>> most of the year. I was a regular visitor for the two years before I moved
>> there and continued to dive regularly for a further three years after
>> leaving the island, so I have about 11 years of observation. No data,
>> though.
>>
>> The variation in water temperature for most of those years followed an
>> annual pattern (again, personal observation, no information from
>> dataloggers, etc) which began at around 27 degrees centrigrade in Jan/Feb
>> -
>> end of monsoon season, rising to a maximum of around 29 degrees in the
>> "summer" months and then falling back to 27 degrees by about November as
>> monsoon reappeared. All data from my dive computer (which has been the
>> same
>> for the entire period), but as everyone knows there is variation between
>> computers.
>>
>> I have dived there much less frequently in the last three years but I have
>> been informed that temperature variations do follow broadly the same
>> pattern
>> but with greater variability in onset-end of monsoon season, and slightly
>> wider temperature variation.
>>
>> Two weeks ago I dived two sites that I am very familiar with in Tioman. At
>> both sites water temperature was 30 degrees (as measured on the same dive
>> computer) but there were no signs of bleaching. Perhaps a few colonies of
>> both branching and massive corals were a little pale, but nothing white.
>>
>> Given that they have been sitting in warm water for a few weeks, is it
>> possible that these corals might be acclimatising to the slightly higher
>> temperature? Is it possible that this recent period of warmer than normal
>> water - but not yet bleaching temperature - will increase their chance of
>> survival in the coming weeks as the Pacific bleaching heads back west,
>> according to NOAA predictions?
>>
>> If anyone is interested, our Tioman Field Station can now provide somewhat
>> more scientific observation capabilities than my own personal
>> observations,
>> including better temperature and condition (bleaching) monitoring. Feel
>> free
>> to contact us if you want more information on the situation in Tioman.
>>
>> Regards
>>
>> Julian Hyde
>> General Manager
>> Reef Check Malaysia
>> +60 3 2161 5948
>> www.reefcheck.org.my
>> Follow us on Facebook at www.facebook.com/rcmalaysia
>>
>> HEARD A FISH BOMB? TEXT US AT 011 2532 7368 WITH DATE, TIME AND LOCATION!
>>
>>
>> -----Original Message-----
>> From: coral-list-bounces at coral.aoml.noaa.gov
>> [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Douglas
>> Fenner
>> Sent: Friday, 13 November, 2015 10:41 AM
>> To: coral list
>> Subject: SPAM R2: [Coral-List] coral reefs and climate change: new article
>>
>> Spalding and Brown. Warm-water coral reefs and climate change.
>>
>>
>> http://www.sciencemag.org/content/350/6262/769.full?utm_campaign=email-sci-t
>> oc&et_rid=17045989&et_cid=89899
>> <http://www.sciencemag.org/content/350/6262/769.full?utm_campaign=email-sci-toc&et_rid=17045989&et_cid=89899>
>>
>> Science Nov 13, 2015
>>
>> Open-access.
>>
>> Cheers, Doug
>>
>> --
>> Douglas Fenner
>> Consultant, corals, coral reefs, coral identification
>> "have regulator, will travel"
>> PO Box 7390
>> Pago Pago, American Samoa 96799 USA
>>
>> phone 1 684 622-7084
>>
>> Join the International Society for Reef Studies. Membership includes a
>> subscription to the journal Coral Reefs, and there are discounts for pdf
>> subscriptions and developing countries. Check it out! www.fit.edu/isrs/
>>
>> "Belief in climate change is optional, participation is not."- Jim Beever.
>> "Everyone is entitled to their own opinion, but not to their own
>> facts."-
>> Daniel Patrick Moynihan.
>>
>> Exxon and probably other fossil fuel companies have long known that global
>> warming is real and mostly caused by humans, because their own scientists
>> did some of the earliest good studies that showed it was true. But they
>> decided to fund a denial campaign to protect their profits, which has
>> worked very well.
>>
>>
>> http://www.democracynow.org/2015/10/21/prison_for_exxon_execs_calls_grow?utm
>>
>> _source=Democracy+Now%21&utm_campaign=c6b4701477-Daily_Digest&utm_medium=ema
>> il&utm_term=0_fa2346a853-c6b4701477-191096773
>> <http://www.democracynow.org/2015/10/21/prison_for_exxon_execs_calls_grow?utm_source=Democracy+Now%21&utm_campaign=c6b4701477-Daily_Digest&utm_medium=email&utm_term=0_fa2346a853-c6b4701477-191096773>
>>
>>
>> http://www.ucsusa.org/global-warming/fight-misinformation/climate-deception-
>> dossiers-fossil-fuel-industry-memos#.VjRnorerTIU
>> <http://www.ucsusa.org/global-warming/fight-misinformation/climate-deception-dossiers-fossil-fuel-industry-memos#.VjRnorerTIU>
>>
>> Climate change could cost trillions more in damage, because of thawing
>> Arctic permafrost. (a mere $3-166 Trillion, while even without Arctic
>> warming, climate change is estimated to cost $326 Trillion globally. The
>> entire world economy is only about $72-85 Trillion a year.)
>>
>>
>> http://news.sciencemag.org/climate/2015/09/climate-change-could-cost-trillio
>>
>> ns-more-damages-because-thawing-arctic-permafrost?utm_campaign=email-news-la
>> <http://news.sciencemag.org/climate/2015/09/climate-change-could-cost-trillions-more-damages-because-thawing-arctic-permafrost?utm_campaign=email-news-la>
>> test
>>
>> website: http://independent.academia.edu/DouglasFenner
>>
>> blog: http://ocean.si.edu/blog/reefs-american-samoa-story-hope
>> _______________________________________________
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>>
>>
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>
>
>
> --
> 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
Consultant, corals, coral reefs, coral identification
"have regulator, will travel"
PO Box 7390
Pago Pago, American Samoa 96799 USA
phone 1 684 622-7084
Join the International Society for Reef Studies. Membership includes a
subscription to the journal Coral Reefs, and there are discounts for pdf
subscriptions and developing countries. Check it out! www.fit.edu/isrs/
"Belief in climate change is optional, participation is not."- Jim Beever.
"Everyone is entitled to their own opinion, but not to their own facts."-
Daniel Patrick Moynihan.
G20 nations spend $452 billion a year supporting fossil fuels: study.
Support for fossil fuels was four times higher than for renewable energy.
http://news.yahoo.com/g20-nations-spend-452-bn-supporting-fossil-fuels-003713410.html
Exxon and probably other fossil fuel companies have long known that global
warming is real and mostly caused by humans, because their own scientists
did some of the earliest good studies that showed it was true. But they
decided to fund a denial campaign to protect their profits, which has
worked very well.
http://www.democracynow.org/2015/10/21/prison_for_exxon_execs_calls_grow?utm_source=Democracy+Now%21&utm_campaign=c6b4701477-Daily_Digest&utm_medium=email&utm_term=0_fa2346a853-c6b4701477-191096773
http://www.ucsusa.org/global-warming/fight-misinformation/climate-deception-dossiers-fossil-fuel-industry-memos#.VjRnorerTIU
Climate change could cost trillions more in damage, because of thawing
Arctic permafrost. (a mere $3-166 Trillion, while even without Arctic
warming, climate change is estimated to cost $326 Trillion globally. The
entire world economy is only about $72-85 Trillion a year.)
http://news.sciencemag.org/climate/2015/09/climate-change-could-cost-trillions-more-damages-because-thawing-arctic-permafrost?utm_campaign=email-news-latest
website: http://independent.academia.edu/DouglasFenner
blog: http://ocean.si.edu/blog/reefs-american-samoa-story-hope
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