Page 28 - ARUBA TODAY

A28 SCIENCE
Saturday 6 OctOber 2018
APNewsBreak: Another rare fish pulled back from extinction

By DAN ELLIOTT ing reservoirs, or removing
Associated Press them by electrofishing —
DENVER (AP) — Another stunning them with electric-
rare Colorado River fish has ity and euthanizing them
been pulled back from the with an overdose of anes-
brink of extinction, wildlife thetic.
officials said Thursday, the Changing the fish from en-
second comeback this dangered to threatened
year for a species unique to will allow more flexibility in
the Southwestern U.S. the way it is protected, said
The U.S. Fish and Wildlife Kevin McAbee, deputy di-
Service recommended rector of the recovery pro-
reclassifying the ancient gram.
and odd-looking razorback Under endangered status,
sucker from endangered to individual fish have to be
threatened, meaning it is protected, but threatened
still at risk of extinction, but status means biologists can
the danger is no longer im- take steps to improve the
mediate. overall population even
The Associated Press was if some fish might be hurt,
briefed on the plans before McAbee said.
the official announcement. Razorbacks still face chal-
Hundreds of thousands of lenges. The first-year sur-
razorbacks once thrived vival rate of hatchery fish,
in the Colorado River and each roughly 14 inches (36
its tributaries, which flow centimeters) long, is about
across seven states and 20 percent or less in the
Mexico. wild, Chart said. It climbs to
By the 1980s they had 80 percent after that.
dwindled to about 100. Drought, climate change
Researchers blame non- and increasing human de-
native predator fish that mand are straining the riv-
attacked and ate the ra- ers, which makes it harder
zorbacks and dams that for fish to survive.
disrupted their habitat. McAbee said the Fish and
Their numbers have Wildlife Service took the
bounced back to between This undated photo provided by the U.S. Fish and Wildlife Service shows Katie Creighton of the Utah river's uncertain future into
54,000 and 59,000 today, Division of Wildlife Resources and Brandon Albrecht, of Bio-West, a government contractor, hold- account before recom-
thanks to a multimillion-dol- ing two large razorback suckers collected from Lake Powell, a reservoir on the Colorado River. mending the change for
lar effort that enlisted the Associated Press the razorbacks. Their long
help of hatcheries, dam lifespan helps them endure
operators, landowners, na- In March, the Fish and Wild- 40 years. ing, Chart said. The Fish low-water years when few
tive American tribes and life Service recommended Razorbacks have been and Wildlife Service began young fish survive, he said.
state and federal agen- changing the humpback around for between 3 mil- capturing the remaining Cooperation among water
cies. chub from endangered to lion and 5 million years, wild razorbacks and mov- users in 2018, a year of dev-
"It's a work in progress," said threatened. It takes 18 to but trouble arrived as the ing them to hatcheries to astating drought in much
Tom Chart, director of the 24 months to complete the population expanded in begin rebuilding the popu- of the Southwest, shows the
Upper Colorado River En- process, including a public the Southwest. State and lation. razorbacks' needs can be
dangered Fish Recovery comment period. federal agencies began The agency designated ra- accommodated, McAbee
Program. "We get more fish The razorback sucker's introducing game fish into zorbacks an endangered said.
out in the system, they're name comes from a sharp- the Colorado without real- species in 1991, although "Things could have been
showing up in more places, edge, keel-like ridge along izing they would devour the Utah and Colorado enact- catastrophic," he said.
they're spawning in more its back behind its head. native fish, Chart said. A ed state protections earlier. Taylor McKinnon of the
locations." Chart thinks the ridge may spurt of dam-building was Biologists began restocking Center for Biological Diver-
Chart's program oversees have evolved to help the a boon to cities and farms rivers with hatchery-raised sity is doubtful about how
the campaign to restore fish stay stable in the tur- but interrupted the natural razorbacks in 1995. Now, healthy the razorbacks re-
the razorback sucker and bulent waters of the Colo- springtime surge of melting about 55,000 are released ally are.
three other fish, all of them rado. snow, which in turn shrank into the Colorado and its The government's reliance
found only in the Colorado It can grow up to 3 feet (1 the floodplains that provid- tributaries annually. on hatcheries to boost the
River system. meter) long and live up to ed a safe nursery for young The Fish and Wildlife Service population shows they are
razorbacks. began working with dam not self-sustaining, he said,
Dams also made parts of operators to time water re- and he worries about their
the rivers too cold for ra- leases to help razorbacks future in the overtaxed Col-
zorbacks, because they re- spawn and restore flood orado River.
lease water from the chilly plains for them to mature. "I think the elephant in the
depths of reservoirs. And Some dams were modified room right now with re-
they blocked the natural to help razorbacks to get gard to recovery is climate
migration of the fish. by. change and river flows and
By the late 1980s, most of Wildlife officials began rein- regional aridification," he
the wild razorbacks were ing in non-native predator said.
old, an ominous sign they fish with nets and screens "We're skeptical of the mer-
were no longer reproduc- to keep them from escap- its of this," McKinnon said.q