[Coral-List] Thoughts on coral decline and the future

Douglas Fenner douglasfennertassi at gmail.com
Sat May 20 21:57:46 EDT 2017


      I should have added something like 'coincidence is, however, a very
good source of hypotheses to test.'  It rightly makes us suspicious.  Some
will pan out, others won't.  I'll add to Mike's comment that African dust
on Caribbean reefs also adds to the point that land-based pollution can
extend vastly farther than we normally think.  Hawaii gets enough dust from
the Gobi desert in Asia to fertilize nutrient-poor soils, as documented in
an article Gene sent me earlier (Chadwick et al, 1999).  The other side of
the coin is that doesn't necessarily mean that Hawaii reefs are affected by
that dust, it may be trace nutrients compared to the nutrients available to
the reef from local island runoff.  Plus, there are parts of the oceans
that receive very little dust, the area around French Polynesia receives
about 1000 times less dust than areas near the Asian mainland, like
Okinawa, Japan (as shown in a map in the same article).  But indeed Mike is
spot on, no reefs in the world escape at least some effects of humans, in
one way or another.  Some have much more, others have much less, and the
patterns are different for mass coral bleaching, dust, nitrogen, fishing,
and so on, and the patterns vary over time as bleaching obviously does (one
area gets hit this time, another area gets hit a different time).  I've
been told that the Phoenix Is., part of Kiribati in the Pacific, very
remote, used to be swarming with reef sharks.  Then a distant water fishing
fleet bought the right to fish them.  In less than a year, there were few
left.  Poachers have been taking sharks in Chagos for years, shark
populations are down there from what they used to be, and the poachers are
hard to stop.  Fishing can extend to the most remote reefs in the world,
and have major effects, with the biggest fish usually the first to go.
    Cheers, Doug

Chadwick, et al. 1999.  Changing sources of nutrients during four million
years of ecosystem development.  Nature 397: 491-497.   Not open access.

As soils develop in humid environments, rock-derived elements are gradually
lost, and under constant conditions it seems that ecosystems should reach a
state of profound and irreversible nutrient depletion.We show here that
inputs
of elements from the atmosphere can sustain the productivity of Hawaiian
rainforests on highly weathered soils.  Cations are supplied in marine
aerosols and phosphorus is deposited in dust from central Asia, which is
over 6,000km away

On Fri, May 19, 2017 at 4:30 AM, Eugene Shinn <eugeneshinn at mail.usf.edu>
wrote:

> Fenner is correct when he says, "Coincidence doesn't prove causality."
> The exception however, seems to be  when coral demise is correlated with
> sewage or increasing human population near reefs. As a friend once
> advised me. "Your dust hypothesis is not accepted because no one can
> figure out how to make money from it." From my experience I might also
> add one can't get funded to do the research needed to find proof either
> way. Many have tried and failed. And besides who wants to work on a
> subject that can't be controlled or fixed. 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
> ---------------------------------- -----------------------------------
>
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-- 
Douglas Fenner
Contractor for NOAA NMFS, and consultant
"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
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"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.

Study: Stopping global warming only way to save coral reefs.
https://www.yahoo.com/news/study-stopping-global-warming-only-way-save-coral-180833431.html

'Extreme and unusual' climate trends continue after record 2016.
http://www.bbc.com/news/science-environment-3932

A roadmap for rapid decarbonization
http://science.sciencemag.org/content/355/6331/1269?utm_campaign=toc_sci-mag_2017-03-23&et_rid=17045989&et_cid=1233226


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