In article <bhoc06$j9a$1@pencil.math.missouri.edu>, Mark Graffis says...

Coral reefs doomed, study says / Centuries of overfishing killing ecosystems
Coral reefs doomed, study says
Centuries of overfishing killing ecosystems
http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/08/16
/MN227977.DTL

Keay Davidson, Chronicle Science Writer Saturday, August 16, 2003

Pummeled by overfishing, the world's coral reef ecosystems "will not survive
for more than a few decades" unless drastic action is taken to protect them,
experts warn.
To forestall a disaster that could devastate marine life, expose populous
coastlines to stormier waves and economically devastate a tourism-dependent
nation like Australia, the United States and other nations should vastly
expand the designated "no take" zones -- where fishing and other
exploitation is banned -- in coral ecosystems, said one author of an article
for Friday's issue of Science.
Historical evidence dating back thousands of years proves that overfishing,
not recent coral diseases or other causes, is the main cause of the slow
death of the world's coral ecosystems, marine paleontologist John Pandolfi
of the Smithsonian's National Museum of Natural History and 11 other
researchers say in the article.
"Overfishing seems to be the largest 'signal' that explains our data,"
Pandolfi said.
Another co-author, marine ecologist Enric Sala of Scripps Institution of
Oceanography in La Jolla, said, "What we're seeing in coral reefs is
something akin to turning a tropical jungle into a golf course."
So far they've documented only one out-and-out extinction of a coral reef
inhabitant -- the Caribbean monk seal. But over the centuries, many other
coral reef denizens have declined to the point where they have "no
ecological impact -- they're functionally 'gone,' like coral trout, snapper,
many of the turtles, (and) the manatees," Pandolfi said.
Because coral ecosystem life forms are so interdependent, the continual loss
of species "is like taking bricks out of a building, one by one. At a
certain point the building is going to come crashing down," he added. "There
are places like Jamaica where the percentage of live coral (as opposed to
dead coral) is down to 5 percent."
As moviegoers who've seen "Finding Nemo" know, a coral reef "provides a lot
of places for fish to live. Coral reefs occupy about 0.2 percent of the
world's oceans, yet they contain 25 percent of the species diversity,"
Pandolfi said.
For fish, coral reefs are combination condos and restaurants. They're
attractive to fish partly because they provide shelter from predators and
all the food they can swallow. They also offer numerous idiosyncratic
ecological "niches" for those oddball fish -- the loners and bohemians of
the undersea world -- who prefer to, say, burrow into the sand beneath the
coral rather than hobnob within the coral complex itself.
Ever since humans began fishing thousands of years ago, species that jam the
undersea metropolises called coral ecosystems have been gradually
disappearing -- the biggest species first, such as green turtles --
according to the researchers' analysis of historical and archaeological
records.
They pored over documents such as Colonial-era records of fish catches from
14 coral reef ecosystems in the Atlantic and Pacific oceans and Red Sea,
including Australia's Great Barrier Reef and coral reefs of the Caribbean.
One of the 12 co-authors, zoology Professor Karen A. Bjorndal of the
University of Florida, and her colleagues found more than 400 documents,
some of them going back to the British colonial era and earlier, that
recorded fish catches over the centuries in the Bahamas alone. They learned
that native Bahamians severely depleted the coral ecosystem's green turtles
long before the Brits arrived.
"I used to think that green turtles were basically in pristine shape when
Columbus arrived (in Bahama five centuries ago), and I don't think that
anymore," Bjorndal said in a press release issued by the university.
Based on the historical records, overfishing should be targeted as the No. 1
cause of coral ecosystem decline, the scientists concluded.
As an analogy, "imagine if 90 percent of the redwoods disappeared in
Northern California," Sala said.
One solution: No-take zones should be greatly expanded in the world's coral
ecosystems, Pandolfi said in a phone interview. The U.S. government has
already designated five percent of coral ecosystems under its control as no-
take zones. But Pandolfi advocates boosting the percentage to as high as 50
percent.
Pandolfi cites a legal precedent: The state of California's recent move to
greatly expand protection to marine ecosystems off its coast. During the
last year, the California state Fish and Game Commission boosted to 11
percent the no-take share of the 1,500-square-mile Channel Islands National
Marine Sanctuary off Santa Barbara and Ventura. The previous percentage was
less than 1/10th of one percent, according to ocean environmental activists.
Besides threatening the food supply of much of the world, reef loss could
imperil natural harbors that are sheltered by coral formation and could
undermine tourism based on the appeal of vibrant coral life.
Failure to prevent continued coral reef deterioration could turn countries
such as Australia -- which are dependent on tourism at attractions such as
the Great Barrier Reef -- into "Third World countries," Pandolfi said.
Some anti-environmentalists might scoff, saying that humanity will continue
to muddle through whatever happens to the coral reefs, Pandolfi
acknowledged. He added: "If you want to live in a world where the ocean is
mostly jellyfish and bacteria, there's nothing I can do about it."

Contact Keay Davidson at kdavidson@sfchronicle.com.