Endangered Colorado River basin fish

Colorado pikeminnow (Ptychocheilus lucius) The Colorado pikeminnow (formerly Colorado squawfish) is a torpedo-shaped fish with an olive-green and gold back, silver sides and white belly. These fish spawn between late June and early September and when they are 5-6 years old and at least 16 inches long. Similar to salmon, Colorado pikeminnow can migrate more than 200 miles to spawn.

The largest minnow in North America and one of the largest in the world, the Colorado pikeminnow at one time may have lived 50 or more years, growing to nearly 6 feet long and weights of up to 80 pounds.

In the last 30 years, the largest Colorado pikeminnow found in the upper Colorado River basin was nearly 38 inches long and weighed about 25 pounds. The Colorado pikeminnow was called "white salmon" and "Colorado salmon" by early settlers, who valued it for food and as a sport-fish. It was the Colorado River's top predator in the early 1900s and has been known to take anglers' bait in the form of mice, birds and even small rabbits, despite that its only "teeth" are found on a bony, circular structure located deep within its throat. This fish also readily strikes lures and live bait used to catch catfish and northern pike. Some people may have heard about other species of pikeminnow that are plentiful in other parts of the country. However, these other pikeminnow are different species of fish and are not endangered.

Colorado pikeminnow are thought to have evolved more than 3 million years ago. (Also see: Historical perspective.)

Status and distribution:

• Listed as endangered by U.S. Fish and Wildlife Service in 1967; given full protection under the Endangered Species Act of 1973.
• Listed as endangered under Colorado law since 1976; downlisted to threatened in 1998.
• Protected under Utah law since 1973.

Colorado pikeminnow were once abundant in the main stem of the Colorado River and most of its major tributaries in Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada, California and Mexico. Now, they exist primarily in the Green River below the confluence with the Yampa River, the lower Duchesne River in Utah, the Yampa River below Craig, Colo., the White River from Taylor Draw Dam near Rangely downstream to the confluence with the Green River, the Gunnison River in Colorado, and the Colorado River from Palisade, Colo., downstream to Lake Powell. Biologists believe Colorado pikeminnow populations in the upper Colorado River basin are now relatively stable and in some areas may even be growing. In the Green River, for example, research indicates Colorado pikeminnow populations may be on the rise. Biologists believe this may be occurring because of changes made in how Flaming Gorge Dam now is being operated.

Recovery strategies: The primary strategies being used to recover this fish species are to maintain more natural river flow patterns by releasing more water from dams in the spring, stabilize flows in late summer for young fish, ensure that stocking of non-native fish does not conflict with endangered fish recovery and build passageways and "ladders" around certain dams and barriers to allow endangered fish to migrate up and down the river. Recovery goals: Colorado pikeminnow will be considered eligible to be reclassified from federally endangered to threatened when naturally self-sustaining populations are being maintained in the following areas: The Green River from its confluence with the Colorado River to its confluence with the Yampa River, the lower 137 miles of the Yampa River, and the lower 150 miles of the White River. The Colorado River from Palisade, Colo., to Lake Powell. The San Juan River from Lake Powell upstream to the confluence of the Animas River.

This fish species will be eligible for removal from the federal endangered species list when all of the following conditions have been met:

• Self-sustaining populations exist in the areas of the Green, Colorado and San Juan rivers identified above.
• A population exists and habitat has been protected either in the Salt River or in the Verde River.
• The threat of significant "fragmentation" of the population has been removed. (Fragmentation refers to separation between fish populations caused by geographical distance or by physical barriers.)
• Essential habitats, including primary migration routes, required stream flows and necessary water quality, have been legally protected.
• Other identifiable threats that could significantly affect the population have been removed.

More specific recovery goals are under development and will be published in draft in the Federal Register in early 2001. The recovery goals consist of both demographic criteria and criteria to minimize or remove threats. The objective, measurable criteria are presented for both downlisting and delisting for each of the four endangered fishes throughout their range.

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