[Coral-List] Endangered species status will be considered for 82 corals

[Michael Risk]

Hi Bill, Jeremy.

As you are both aware, I am NOT a specialist in ancient reefs, so will
only add a couple of comments/factoids here.

1. the best Cretaceous reefs I have seen so far would be lost in the
Permian reefs of West Texas, which in turn are smaller than those huge
structures made in the Devonian of the Canning Basin and Western
Canada.

2. in the Cretaceous, all the ice caps melted. Funny how one thing is
connected to another. If/when this happens in the future, at least 1/3
of the human race would be displaced.

....having said that: keep at 'em, Gene.

Mike

On Mon, 22 Feb 2010 07:50:35 -0500
 Bill Allison <allison.billiam at gmail.com> wrote:
> Encouraged by Jeremy's inquiry and given the Cretaceous lasted for
> some time
> I wonder whether or not Gene's "grandest reefs" of the Cretaceous
> were
> coincident with the very high CO2 levels he describes. The literature
> I have
> to hand suggests that high CO2 levels occurred in the mid to late
> Cretaceous
> with implications for skeletal development and evolution (e.g.,
> Medina et
> al., 2006; Stanley, 2003; Stanley & Fautin, 2001) and that reef
> communities
> with important coral components waned to insignificance from the late
> Jurassic to the mid-late Cretaceous (Wood, 1999; 112 & 114),
> apparently as
> CO2 levels rose. The rudists seem to have intermittently flourished
> in the
> face of these conditions for reasons that are debated but they may
> not have
> formed reefs as technically defined, let alone diverse reef
> communities
> (inferred from Wood, 1999; 114-115). With the aim of better
> understanding
> the problem, perhaps a specialist in ancient reefs and their
> environments
> would care to comment on my superficial presentation of the
> situation?
> Thanks,
> Bill
> 
> On Sat, Feb 20, 2010 at 2:04 PM, Jeremy Woodley
> <jdwoodley at yahoo.co.uk>wrote:
> 
> > Dear Gene,
> >
> > I’d be grateful if you could explain (to a relative ignoramus) how
> it could
> > be that very high levels of atmospheric CO2 in the Cretaceous did
> not so
> > reduce ocean pH as to impair coral calcification, which is a
> concern today?
> > Were the oceans better buffered? Or must we assume that, given
> time,
> > organisms adapted?
> >
> > Eugene Shinn wrote:
> > ......................................................  Just look
> to the
> > geologic record. The
> > > grandest reefs the world has ever known grew during the
> Cretaceous
> > > when Co2 levels were more than 7 times present levels.
> >
> > Jeremy Woodley
> >
> > Retired from the Centre for Marine Sciences, University of the West
> Indies,
> > Jamaica.
> >
> >
> >
> >
> >
> > _______________________________________________
> > Coral-List mailing list
> > Coral-List at coral.aoml.noaa.gov
> > http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> >
> 
> 
> 
> -- 
> Reality, as usual, beats fiction out of sight.
> Conrad, 1915
> 
> "Reality" is a dangerous word that should always be incarcerated in
> quotation marks.
> Nabokov
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Mike Risk
Marine Ecologist
PO Box 1195
Durham Ontario
N0G 1R0