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Sacramento
Bee
November
20, 2009
by Matt
Weiser
The fish that define life in Sacramento's
rivers are at greater risk of extinction than experts had
previously thought.
A study by UC Davis scientists, released
on Wednesday, predicts 65 percent of California's salmon
and trout species may become extinct within a century.
The research was commissioned by the environmental group
California Trout to call attention to the plight of 31 native
salmon, steelhead and trout species in the state. Three researchers
from the UC Davis Center for Watershed Sciences examined
threats to the fish and estimated their likelihood for extinction.
The study was led by Peter Moyle, professor
of fish biology at UC Davis and a leading authority on salmon
and trout.
"I had a feeling that things were not good," Moyle
said. "But I did not realize how many collectively were
actually in serious trouble and how underestimated the threats
to many of these fish were."
Among the most threatened species are
coastal coho salmon, which require cold streams shaded by
thick wooded habitat. Instead, many of those streams have
been degraded by logging and development.
Less threatened are Central Valley
fall-run chinook, the most abundant species in California
and a foundation for the commercial harvest. However, Moyle
warned this may be changing. This year the run collapsed,
causing the closure of commercial fishing and limited recreational
fishing to brief seasons on the Sacramento and Klamath rivers.
These and several other salmon and
steelhead species must navigate treacherous waters of the
Sacramento-San Joaquin Delta, where they're all threatened
by pollution and some are killed in water diversion pumps.
"The fish don't lie, and they are right now telling
us the truth about the future of the water in our state," Moyle
said. "We have a choice right now. We can allow the
degradation of our waters to continue ... or we can take
action and bring them back from the brink of extinction."
Like freshwater trout, salmon and steelhead
are born in California's streams and rivers. But unlike trout,
salmon and steelhead migrate to the ocean as juveniles, then
return to freshwater to spawn near their birthplace. The
study found threats to these ocean-going species are even
worse: 83 percent are at risk of extinction, Moyle said.
But trout are at risk as well. The
inland species face threats including pollution and loss
of habitat from land development, logging, cattle grazing,
mining and competition by foreign species. Among the threatened
species is the state's official fish, the California golden
trout.
Brian Stranko of CalTrout warned that
the state risks losing an estimated $2 billion in annual
economic benefits generated by recreational angling, and
billions more from commercial fishing.
"Each of the salmon, trout and steelhead species occupies
an essential niche in the food web," said Stranko, the
group's CEO. "We need cold, clean water for our fish,
our people and the economy of California."
Just how much water is needed to protect
native fish -- including endangered Sacramento River winter-run
chinook and threatened Delta smelt -- is the subject of two
cases before a federal judge in Fresno. Water agencies say
a court order restricting their water deliveries to protect
smelt has already caused them to fallow fields and impose
water rationing.
The advocates didn't call for further
cutbacks but said California must find a way to fully fund
the Department of Fish and Game to enforce existing laws.
The department doesn't have the money to hire enough game
wardens, biologists and permit analysts, and more budget
cuts loom.
They also recommend overhauling hatchery
and fish-stocking practices, which may weaken the species
by erasing wild genetics.
The department is conducting an environmental
study of its hatchery and stocking practices. A Sacramento
judge this month ordered the state to negotiate with two
environmental groups, which challenged current practices,
to agree on interim changes until the study is done.
QUICK FACT Among the most threatened
species are coastal coho salmon, which require cold streams
shaded by thick wooded habitat.
The Associated Press contributed to
this report. Call The Bee's Matt Weiser, (916) 321-1264. |
