http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2003/08/16/MN227977.DTL
Saturday, August 16, 2003
San Francisco Chronicle
Coral reefs doomed, study says
Centuries of overfishing killing ecosystems
Keay Davidson, Chronicle Science Writer
QUOTE:
"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.'"
[ See
photograph from original article... ]
CAPTION:
"Deep sea corals, such as these near Alaska, provide shelter
and food for a huge variety of fish and other marine life."
Auke Bay Laboratory photo by Robert Stone
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.
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