In a study sponsored by Trout Unlimited, private fisheries consultant Dr.
Phillip Mundy found that within 18 years Chinook salmon on the Snake River will
be extinct if current trends continue. Mundy based his conclusion on an
extinction model, which uses spawner to spawner ratios to evaluate population
fluctuation from one generation to the next. The number of salmon spawning in a
given year is recorded and then compared to the number recorded for the parent
generation. If the resulting ratio is less than one, the population is
declining. Spawner ratio data is available from 30 years ago to the present,
providing Mundy with a very credible data set. Mundy emphasized the urgency of
the situation. "If we have any problems with the study, it’s that we’re too
conservative," he said. "We could be too optimistic about the signs of
extinction. It could be that we have slightly less time."
Mundy’s study doesn’t offer any solutions, but many people in the scientific
community feel that breaching the dams is the only way to save the Chinook
salmon. Over 200 scientists made this statement by sending a letter to the
White House in March. PATH scientists as well as experts from various advocacy
groups have come to the same conclusion. The western division of the American
Fisheries Association has voiced its support for breaching the dams by passing
a resolution stating that if the salmon are to be saved, the dams must be
breached. It remains to be seen whether policy makers will opt for breaching or
not, and Mundy says that there is no time to lose.
for more information, also see http://www.tu.org
Snake River chinook extinction set at 2017”, Environmental Network News, 12
July 1999. Read entire article at:
Endangered Colorado pikeminnow stimulates restoration efforts
The endangered Colorado pikeminnow was pushed to the brink of extinction in the
1960s by Western dam-building and government efforts to poison and replace them
with gamefish such as largemouth bass. Three decades later, federal officials
are spending millions to help the rare fish swim around the river-blocking
structures. The federal government built its first pikeminnow fish ladder in
1996 around the 8-foot Redlands Diversion Dam on the Gunnison River. One
pikeminnow swam up the 300-foot-long ladder in 1996. Eighteen followed in 1997,
and 23 more passed through last year. In addition to the endangered species,
27,000 other fish have used the passageway.
Sometime this fall, federal officials said they hope to start building another
fish ladder, for $3.4 million, around the Highline Diversion Dam, known locally
as the Roller Dam, on the Colorado upstream of Grand Junction. That ladder,
combined with another $2 million federal plan to tear down an unused 10-foot
structure called the Price-Stubb Dam, would open another 55 miles of river
habitat to the migratory pikeminnow.
"If it reopens that habitat, it seems like money well spent,'' said Peter
Evans, director of the Colorado Water Conservation Board, which helps finance
new dams in the state. "We'd like to see the fish benefit.'' Federal attempts
to tear down the Price-Stubb Dam, which hasn't been used regularly by water
users since the 1920s, have been complicated by a proposal to add a
hydroelectric plant. That proposal remains unsettled. For more information on
efforts to remove Price-Stubb Diversion Dam, contact Steve Glazer of the Sierra
Club Colorado River Task Force at 970.349.6646.
(Obmascik, Mark, "Fish climb ladders of success," Denver Post, 9 July, 1999.
Full story retrieved at:
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org