[log in to unmask] wrote:
> An article in todays paper notes that A sizeable percent of Elkhorn Coral has died off due to the warming of the waters in the Caribbean. 40% in some areas.
>     The article notes that the reefs are vital for fish, lobsters and "other sea life". I assume that "other sea life" includes the mollusca. Since the source of the warming is solar radiation, there isn't much "we" can do about it. But perhaps we should be monitoring the effects. Any thoughts, ideas?
>       Art

The major part of the reef system here in Florida, which
stretches a couple hundred miles from the Tortugas to Palm
Beach, was once a shallow barrier reef and there are places
where the ancient elkhorn, which can only live in very shallow
water, is quite easily seen at 60 - 65 fsw. Over the past 10,000
years or so, this reef has grown by adding successive layers of
species of corals. Currently, the top of the reef is at about 45
fsw at the top, 65 fsw at the inside base, and 85 fsw at the
outside base, and the corals are what would be expected at those
depths.

Elkhorn and staghorn, are very shallow water species, typically
awash and therefore found in areas that have been under water
for only a few thousand years at most, and on unstable bottoms.

Global warming does not kill reefs, it builds reefs. But the
reefs are indeed getting whacked big time.

Here in Florida, we are rapidly and systematically killing off
the corals and making it impossible for them to reestablish
themselves.

Beach renourishment, for example, dredges coral sands of 62 -
250 microns, (along with billions of live-ground mollusks,
including juvenile S. gigas, a supposedly protected species) and
deposits this fill atop silica beach sands. The result is an
unstable mix which drifts into the shallows, increasing
turbidity and obliterating all those "beginnings" - the elkhorn
and staghorn - just off the beach. The good news is that the
renourished beaches erode very quickly, keeping the Army Corps
of Engineers from running out of things to do.

Treated sewage, for another example, is treated to remove
certain things but still contains huge amounts of nitrogen and
ammonia. One local plant dumps 13 million gallons a day directly
onto the Boynton Ledge, until recently one of the world's most
beautiful reefs. It has been proven that elevated ammonia levels
in this discharge is the cause of a cyanobacteria that has
devastated the reef. The county agrees. The state agrees, and
has refused to reissue the treatment plant's permit. But there
is no process for stopping the discharge - the plant simply
continues operations without a permit.

Soon, a seven-mile stretch of reef that was home to 134
personally-collected species of mollusks, about 140 species of
sponge, perhaps 60 species of coral, half a dozen tunicates
including one that I believe has never been described, and all
the other critters I once knew well will be just a big dead rock.

The reefs - and the mollusks - are out of sight. Out of sight,
out of mind. No one is bothered by what goes on below the
surface, whether it is slaughter of protected S. gigas or
destruction of the reef life.

I'm glad I've seen the underwater world, and will be able to
tell my grandkids what was there, back then. They will never see
it for themselves.

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