[Coral-List] Question Thermal vs PH shift

[Simon Donner]

Hi James,

I fear reefs are just not high on the political agenda, they are not seen as
crucial to humanity, so when push comes to shove, the threats fall on deaf
ears. Of course, the scientific community is also to blame. Much is made of
the inbred reticence of scientists to sound the alarm or to be convinced it
needs sounding. Maybe we're simply afraid to cry wolf and be wrong. It is
easier for many to talk about a distant future, when we'll all be dead, than
something that is happening now or in the near future and that therefore
requires immediate action.

Simon

On Jan 14, 2008 6:03 AM, James Cervino PhD. <jcervino at whoi.edu> wrote:

> Hi Simon, You are correct! It is depressing, however, I spoke to a few
> science
> writers, polititians and students at the undergrad level and they all
> think
> that we have another 75-100 years to control atmospheric CO2 to levels
> that
> will save the corals and their habitat.
>
> This attitude is what allowed to what happen in Bali happen, which is more
> time
> to monitor the situation thereby not putting anything in clear writing
> that
> give us reef scientists a %cut number, and a serious target date to
> reduce.
> Talk of 65% reduction is all pretty, however, this needs to happen if we
> want
> to see the remaining gene pool of 100+ species of Acroporids remain. My
> course
> coordinator at Columbia recently asked me to include "sustainability" in
> my
> last lecture for this field course we are running and I said
> sustainability
> begins at controlling atmospheric CO2, which is the number one killer. I
> dont
> want my son to look through 1000s of slide images of these reefs and see
> what
> they used to look like, I want him to see them in real time in 10 yrs.
>
>
> Quoting Simon Donner <simon.donner at gmail.com>:
>
> * It is rather depressing to read scientists arguing over which threat (T
> vs.
> * pH) is worse. I will say that the discussion of poleward movement of
> corals
> * confuses geological and socio/ecological thinking. Even if corals could
> all
> * move poleward, that would not mean establishment, in the near or even
> the
> * future, of coral reef ecosystems as we know them. And even if that could
> * happen, the more equatorial human communities that had depended on
> * (presumably degraded) coral reefs are still in trouble.
> * _______________________________________________
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> * Coral-List at coral.aoml.noaa.gov
> * http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> *
> *
>
>
>
> Hi Ken long time since NYU,
>
> You make some very valid points in your post. However, what concerns me is
> the
> terminology pertaining to corals establishing themselves poleward in a
> more
> tolerable environment.  The key question is, what types of corals will
> even be
> able to take this journey? For the purposes of addressing the students,
> policymakers, and journalists reading this healthy discussion, I would
> like to
> point out a very important factor. Let's use the 100+ different species of
> Acroporids (the most sensitive to thermal stress). The success of these
> organisms' reproductive productivity can be determined by factors specific
> to
> global and coastal adaptive pressures, i.e., thermal stress,
> sedimentation,
> nutrient enrichment & pathogens. Because these factors are occurring at
> such a
> rapid rate, these thermally sensitive species will not move/adapt within
> the
> time you are hypothesizing.
>
> Sensitive species (all species, really) need time to adapt! As Steven J.
> Gould
> so eloquently stated in the "Return of the Hopeful Monster": The essence
> of
> Darwinism lies in a single phrase: natural selection is the major creative
> force of evolutionary change and no one denies that natural selection will
> play
> a negative role in eliminating the unfit. However, selection occurs by
> building
> "gradual adaptations" in a series of steps (again "time"),  preserving at
> each
> stage, the advantageous part in a random spectrum of genetic variability.
>
> For those who are thinking optimistically, what is the time frame in which
> you're thinking that corals will adapt and move northward?   Did the
> surviving
> corals of the 1998 Indian Ocean Hot-Spot bleaching pass some of these
> heat-tolerant genes north and establish themselves there, thereby escaping
> the
> heat? Is there evidence of this genetic drift? Let's look at the real-time
> observations since the 1982-83 major thermal bleaching event. This will be
> important to investigate the reality of what's occurring. The thermal
> hot-spot
> events have been growing more severe year after year since 1982-83 and I
> have
> not seen documentation of these keystone species' (as we know them)  mass
> northward migration to escape from the heat.  Does anyone have evidence of
> this
> adaptation and drift?
>
> >From our recent clade sub-type experiments I can identify a more heat
> tolerant
> Symbiodinium spp. as shown by (Sotka and Thacker, 2005) and one that
> resists
> Vibrio pathogens during short-term exposure due to unknown defense
> mechanisms.
>  However, as shown by Baker et al. &  LaJeunesse  et al., major
> reef-building
> corals can be found  hosting multiple symbiont species at the clade level.
> However, radiation or drift of these symbioants northward escaping the
> heat
> thereby taking up residence on the top of some algal lawn has to take
> time, and
> not at the time scale some optimists want to think. The projected
> increases in
> the frequency and severity of thermal bleaching events and coral
> resilience
> depends, on whether phenotypic and genotypic changes in host–symbiont
> associations can match the time factors at which their cellular
> biochemical
> processes can adapt. In conclusion, given what we are seeing in real-time,
> this
> genetic adaptation and migration northward to preserve these 100+
> Acroporid spp.
> as we know them, is highly un-probable and will die long before the oceans
> become acidic.
>
> Sincerely- James
> *************************************
> Dr. James M. Cervino
> Pace University & Visiting Scientist
> Woods Hole Oceanographic Inst.
> Department of Marine Chemistry
> Woods Hole MA.
> Cell: 917-620*5287
> ************************************
>
>
>
>
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