GRANTS PASS, Ore. -- New research confirms that
steelhead raised for generations in hatcheries do poorly when they
try to reproduce in the wild, but the first generation of fish
raised from wild parents in hatcheries are as successful at
reproducing in their native rivers as their wild cousins.
The results of genetically testing some 15,000
steelhead returning to the Hood River in Oregon over the past 15
years offer support for federal policies using hatcheries to bolster
threatened and endangered wild runs of salmon and steelhead in the
Columbia Basin.
But Oregon State University geneticist Michael
Blouin, lead author of the study posted last week in the online
version of the journal Conservation Biology, cautioned that relying
on hatcheries to sustain salmon runs is likely to fail in the long
run without restoring river habitats, because the fish raised from
wild eggs hatcheries will soon evolve traits ill-suited to the wild.
In hatchery programs, "we have essentially
created a fish version of white lab mice," Blouin said.
"This means they are very well adapted to being born in a
little plastic tray and being raised in a concrete pond and fed fish
chow. They don't survive that well in the wild.
"This is evolution in real time right before
your eyes."
Hatchery fish make up about two-thirds of the
salmon and steelhead returning each year to the Columbia Basin, the
largest producer of salmon on the West Coast. The returns represent
just 5 percent of historical levels before dams, logging,
agriculture and urban development destroyed much of their habitat.
Conservation groups, Indian tribes, fishermen,
state and federal agencies, the timber industry, agricultural groups
and property rights groups have been battling over whether to rely
on hatcheries for decades.
In 2001, a federal judge ruled that Oregon coastal
coho raised in fish hatcheries must get the same protection under
the Endangered Species Act as Oregon coastal coho that spawned in
the wild, despite the fact that the hatchery fish were descended
from genetic stocks far outside the region.
The federal salmon hatchery policy adopted in 2004
to comply with the ruling was guided by preliminary results of the
Hood River study, said Bob Lohn, northwest regional director of NOAA
Fisheries, which is in charge of restoring salmon.
"We don't expect this to cause us to make
major changes," Lohn said. "But it certainly adds
importance to the hatchery reform effort that is now ongoing in the
Columbia River system."
NOAA Fisheries is reviewing 189 different hatchery
programs, deciding which will keep producing fish and which should
be shut down or forced to adopt modern techniques. It is expected to
be completed in about six months, Lohn said.
Bill Bakke of the Native Fish Society said other
studies have shown that even hatchery fish bred from wild eggs are
inferior to wild fish in behavior, body size and other
characteristics that determine their survival.
He said he expected state and federal agencies
that operate salmon hatcheries to use the study to justify expanding
programs based on wild broodstock, despite the study's cautionary
note that they were likely to fail in the long run.
"This is the end of wild steelhead in the
Northwest," he said.
Mark Chilcote, a conservation biologist for the
Oregon Department of Fish and Wildlife, said he did not expect the
study to change hatchery operations in Oregon, where most are
operated to provide fish for people to catch, not to help struggling
runs survive.
"In that case, the main thing is you want to
create a product that returns a lot of fish to a fishery, minimizes
the impact with wild fish, and is an efficient operation," he
said. "Typically, when you take a wild fish and spawn them and
tray to raise them in a hatchery, it is more difficult, because they
are not as domesticated."
The study extracted DNA from fish scales that have
been collected from every steelhead returning to the Hood River
since 1991. Hood River is a tributary of the Columbia flowing down
the flanks of Mount Hood east of Portland. A dam makes it possible
to sample every fish headed upstream.
By comparing the genetics of fish returning in
different years, they found that fish from traditional hatcheries
using nonnative broodstock for winter steelhead had reproductive
success as low as 6 percent to 11 percent of wild fish, which fish
from hatcheries using wild broodstock had reproductive success
indistinguishable from wild spawners.