[Coral-List] Corals Persist But Bioerosion Rises in Low-pH Waters (Anne Cohen)

Risk, Michael riskmj at mcmaster.ca
Tue Jun 9 16:28:07 EDT 2015

Hi Gene.

I think the conclusions from that paper are (a) depressing and (b) logical. It may perhaps serve to wake up the majority of the reef research community that has ignored bioerosion for a couple of decades.

There are a number of papers that show/suggest that there is a succession, or a sequence, in bioeroding, in which the boring algae are the pioneers that "soften up" the substrate, preparing the way for the other zillion phyla.. In 1977, we showed (Kobluk and Risk, JEMBE 27: 107-115) that the algae are very specific: when attacking Iceland Spar, they seek out the intersections of the twin planes and the cleavage planes, drop right down in-those surfaces are also the surfaces of highest free energy, hence the attacks go even faster if the pH drops.

From: coral-list-bounces at coral.aoml.noaa.gov [coral-list-bounces at coral.aoml..noaa.gov] on behalf of Eugene Shinn [eugeneshinn at mail.usf.edu]
Sent: June 9, 2015 10:32 AM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Corals Persist But Bioerosion Rises in Low-pH Waters      (Anne Cohen)

The Woods Hole press release is interesting. I was concerned about the
proposed connection between acidification and increasing numbers of
borers. One would like to see some experimental evidence that borers
actually favor lower pH. Do such experimental data exist? Borers that
attack wood piling, boats, and limestone do favor areas of restricted
circulation over areas of increased oceanic circulation. For example,
Biscayne Bay supports far more boring and fowling organisms than do the
more open waters of the Florida Keys and the Bahamas. Those differences
in boring fauna are not related to pH. Most likely the greater abundance
of rocky intertidal surfaces in Biscayne Bay that boring and other
fowling organisms favor combined with longer retention time of larvae in
an environment favorable to their success account for the bay’s
increased numbers of boring organisms. Those conditions also are found
in the many lagoons of Palau. Could it be that the greater numbers of
boring organisms that attack coral skeletons there has nothing to do
with acidification? Experimental data may be needed to determine if pH
is the culprit. Gene

On 6/8/15 12:00 PM, coral-list-request at coral.aoml.noaa.gov wrote:
> Corals Persist But Bioerosion Rises in Low-pH Waters (Anne Cohen)


No Rocks, No Water, No Ecosystem (EAS)
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E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
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St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
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