[Coral-List] diver distance et al

Douglas Fenner douglasfennertassi at gmail.com
Sun Aug 11 02:33:03 EDT 2013


Thanks, Dennis, good points.  I completely agree that reef degradation is
likely to be due to several things all at once.  In the Caribbean and
Florida, African dust should surely be added to the list of suspects.  We
need to work on all of them.
      I guess my view is that I don't worry about the natural damage, while
I do worry about the effects of humans.  That said, one of the effects of
humans is to weaken the reef ecosystems so that reefs can't recover from
natural damage, like from hurricanes.  So there is an interaction, and
recovery (or lack of recovery) from any event can no longer be assumed to
be a completely natural.  Crown-of-thorns starfish outbreaks could have
been natural at one time, but now we can't assume they are.
      As a scientist, of course natural disturbances are interesting and
very important for coral reefs, I'm all for studying them.  I would think
that for many, there is little or nothing we can do about the disturbance
itself.  The great mass extinction events happened (long ago), there is
nothing we can do about them, even if a great mass extinction event
occurred now, there might be nothing we could do about it (though NASA is
talking about trying to do something about any big incoming asteroids,
which would be good to do something about if we can).  We can't do anything
to get rid of hurricanes, for instance, that's been tried (seeding clouds)
with no success.  Prepare for them, clean up after them, certainly, but
stop them, unfortunately not.  We can't stop volcanic eruptions,
earthquakes and tsunami's, ENSO (El Nino) etc.  And there are lots of gaps
in the building of reefs.  If I remember, Charlie Veron had an extensive
article in Coral Reefs about those gaps and concluded that mass marine
extinctions may have been produced by bad water conditions in whole
oceans.  Smaller gaps like the ones you point out happen as well.  Perhaps
in Florida due to something like cold weather, or higher ocean levels that
allow bad quality water to flow from huge Florida Bay's shallow areas east
through the Keys onto the reefs.  Many possibilities.  But most of those
are likely to be things we have little control over.  If we can control
them, then good, let's consider what we can do and any possible collateral
damage.  But my impression is that our ability to change geological
processes is very limited.  It is quite true that humans are now having
effects on the climate that are unprecedented and many thought humans could
never do so much to the climate.  Humans have affected just about all the
ecosystems of living things on the planet and now are affecting the
climate.  Unfortunately, not in a helpful way.  We need to contain and
reduce the damage humans do to their environment, including coral reefs.
     Cheers,  Doug


On Sat, Aug 10, 2013 at 4:00 AM, Dennis Hubbard
<dennis.hubbard at oberlin.edu>wrote:

> I'm responding to Doug's recent missive (the one on "natural" versus
>  "human" impacts) using an earlier post to reduce the bandwidth needed for
> the reply. Doug makes a lot of excellent points on the diversity of
> stresses facing coral reefs today. I think it will be useful to remember
> that what we are seeing is probably a response to all of these and that to
> argue that our personal favorites are the only ones deserving of our
> attention is counterproductive. Climate change exacerbates all the others
> and may trump them to the extent that local solutions will fail until
> global issues are abated. At the other extreme, it has been argued that
> dealing with local top-down and bottom-up stresses may increase resilience
> and mitigate issues related to things like bleaching, disease, etc.
>
> As a scientist, I am very comfortable admitting that I don't know where
> the truth lay on this spectrum. And I am equally uncomfortable about
> attempts to advocate for particular solutions based on well-placed biases.
> As a geologist, I admit that my view is longer in scope and may be less
> appropriated than opinions of folks with their noses in the reefs measuring
> things. Nevertheless, I do get very nervous when it is suggested that
> "natural" effects do not have negative effects while "human" ones should be
> the center of our focus. In this regard, I off two observations. First,
> this approach argues that the five major extinctions were, by definition,
> "OK" while recent declines must not be so. I am always brought back to
> Wendell Berry's quote in "Home Economics":     Before we can know what we
> are doing, we need to know what nature would be doing if we were doing
> nothing". As sore as our geological arms get waving at these issues, I
> would suggest that the fossil record is the only game in town....  and our
> invitation to the grown ups' table.
>
> There are two millennial-scale gaps in the Acropora record (and no I'm not
> suggesting extinctions) at ca 3,000 and 6,000 years ago. I am not sure what
> is at the root of these events (I have some strong suspicions but will wait
> until I have the data completed before speaking), but am confident that
> they are real. I do not suggest that these are analogous to recent events
> or that they are cyclical.... only that there are things that make me
> question my own omnipotence regarding recent reef decline and, therefore,
> the appropriate mitigation. So, in the meantime, I keep coming back to
> "if it has good collateral effects", bring it on. I'm perfectly willing  to
> admit down the road that, "gee, reef decline wasn't caused by my favorite
> factor - but now we have cleaner air and water..... Don't I feel stupid!"
>
> Dennis
>
> On Wednesday, April 17, 2013, Douglas Fenner wrote:
>
>> Take a look in Veron (1993) A biogeographic database of hermatypic corals:
>> species of the central Indo-Pacific, genera of the world.  Australian Inst
>> Mar Sci Monogr Ser X: 433 pp.  It has 3 tables of where individual coral
>> species had been found.  The first presents which species had been found
>> in
>> which areas of the east coast of Australia including southern New Guinea
>> to
>> South Australia, the second covers the west coast of Australia, and the
>> third covers Japan and the Philippines.  For the GBR, it is divided into
>> the Coral Sea, Torres Strait, Northern GBR, Central GBR, Pompey and Swain
>> Reefs, and Capricorn and Bunker reefs.  It is of course a bit dated by
>> now,
>> but is the best available for locations within the GBR at this point, I
>> believe.  It does not include species discovered or recognized since 1993,
>> of course.  Veron is working on a new database that will be on the web I
>> believe, which he calls "Coral Geographic."  I assume it will have
>> detailed
>> geographic info on corals from all over the world.  I believe he is close
>> to having it finished and being able to release it.
>>      Cheers,  Doug
>>
>>
>> On Tue, Apr 16, 2013 at 1:48 PM, Scott Atkinson <scabecks at gmail.com>
>> wrote:
>>
>> > Does anyone know of any available coral species presence/absence or
>> > abundance datasets across the GBR? Species of particular interest are
>> > *Hydnophora
>> > exesa, **Seriatopora hystrix, **Acropora formosa, *and *Porites lutea;
>> > *however,
>> > any level of classification would be welcomed.
>> >
>> > Many thanks for any help!
>> > Scott Atkinson
>> > _______________________________________________
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>> > Coral-List at coral.aoml.noaa.gov
>> > http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
>> >
>>
>>
>>
>> --
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>> Pago Pago, American Samoa 96799  USA
>>
>> The views expressed are those of the author alone.
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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*"
>
>


-- 
PO Box 7390
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The views expressed are those of the author alone.


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