Posted by brianc on December 11, 2001 at 12:45:36:
In Reply to: Re: DFAG planted infected abs posted by shark-92107 on December 11, 2001 at 12:29:37:
Agency loosed abalone threat
State Fish and Game officals say diease has not taken hold of red
abalone population despise 1995 mistake
July 12, 2001
By PAUL ENGSTROM
THE PRESS DEMOCRAT
State Department of Fish and Game officials admitted Wednesday they
accidentally contaminated wild red abalone along the North Coast with
the same disease that decimated the black abalone populations of
SouthernCalifornia.
Officials with the department said they have been closely monitoring the
health of Northern California's red abalone ever since they realized
their error in 1999.
Fish and Game officials said while the disease is not now taking hold
of redabalone beds along the North Coast, it does pose a significant
threat.
Tainted abalone seed were introduced to wild populations off the coasts
of FortBragg and Crescent City in 1995 during so-called outplant
projects. The environmentalist-endorsed projects were conducted to learn
whether depleted wild stocks of the prized catch could be buttressed
with farm-raised abalone.
But in 1999, officials discovered that the farm-raised abalone stock
they planted in the wild was contaminated with a bacteria called
rickettsia-like procaryote, or RLP, which causes withering syndrome in
certain types of abalone.
"In retrospect now, it does appear that some of those (seeds) were
infected," said Robert Hulbrock, aquaculture coordinator for Fish and
Game in Sacramento. He said the agency continues to sample wild abalone
between Crescent City and Bodega Bay to monitor the situation.
Though not harmful to humans, the infectious disease attacks black, pink
and red abalone and causes the mollusks to lose weight and eventually
die of starvation.
Hulbrock said withering syndrome has not so far been seen north of San
Francisco, adding that he's "cautiously optimistic" it won't any time
soon.
But he acknowledged that the true extent of the threat will remain
unclear until more studies are done.
The disease is best known for having decimated the black abalone
populations in Southern California in the 1980s, leading to the demise
of the state's commercial abalone industry.
Black abalone populations from San Diego to Cayucos had declined by as
much as 99 percent by 1998. The state imposed a partial ban that year on
shipments of abalone to and from Northern California hatcheries to keep
the disease from spreading northward.
Abalone can host the bacteria that causes withering syndrome, yet not
succumb to it.
Researchers at the department's Bodega Bay Marine Lab are studying the
possibility that North Coast red abalone haven't contracted withering
syndrome because coastal waters north of the Golden Gate are too cold to
permit the bacteria's infection of the mollusks.
But they warn that the situation could change in the event of a
water-warming climate change, such as another El Niņo event.
"We know that in warmer water, this organism causes severe damage," said
Dallas Weaver, president of the Aquaculture Disease Advisory Committee
at the California Department of Fish and Game.
"But we don't know if it causes as much damage in the North -- if any
damage to speak of -- as in Southern California."
Last month, NASA scientists predicted another El Niņo could be as little
as a year away.
Red abalone, which survive from the Marin County coastline north to the
Oregon border, are a favorite catch for sport divers from all over the
state, who have been coming to Sonoma and Mendocino counties since
abalone harvesting was banned south of the Golden Gate in 1997.
Mature mollusks generate significant tourism income for North Coast
communities during the state-sanctioned abalone diving season, which
runs from April through November with a monthlong break in July.
But Weaver said sport divers may unwittingly contribute to the spread of
RLP bacteria when they clean infected abalone and toss the waste back
into the ocean where it is eaten by uninfected abalone.
The threat of withering syndrome has already put a crimp in the
operations of North Coast aquaculture facilities that grow and sell the
millimeters-long abalone seed to abalone farms or grow the mollusks to
maturity for market.