Filters: Categories: Publication (X) > Types: ScienceBase Citation (X) > partyWithName: Julie A Jackson (X)
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Humpback chub (Gila cypha) are listed under the Endangered Species Act of 1973, as amended. In accordance with recovery goals finalized in 2002, a population estimate was completed for adult humpback chub in Westwater Canyon on the Colorado River. This population estimate was conducted from 1998 to 2000 with the objectives of obtaining population estimates for humpback chub and roundtail chub in Westwater Canyon. Sampling occurred during September and October throughout the three years of the study. Three passes were conducted annually with approximately one week between passes. The primary method of capture was via trammel netting with supplemental electrofishing on one pass per year. Population estimates were...
Categories: Publication;
Types: Citation,
ScienceBase Citation;
Tags: Colorado River,
Gila cypha,
Gila robusta,
Westwater Canyon,
growth,
The fifth consecutive year of nonnative control in the lower San Juan River was conducted in 2006. This project was initiated to remove nonnative fish species, and to identify factors involved in movement of striped bass (Morone saxatilis) and other reservoir species out of Lake Powell and into the river. Relationships between these factors and nonnative catch rates were intended to help in the refinement of removal effort timing. Since the formation of the new waterfall at Piute Farms in 2003, channel catfish and other resident nonnative fish have been the focus of removal actions.
The fourth year of nonnative control in the lower San Juan River was conducted in 2005. This project was initiated to remove nonnative fish species, and to identify factors involved in the movement of striped bass (Morone saxatilis) and other lacustrine species out of Lake Powell and into the river. Relationships between these factors and nonnative catch rates were intended to help in the refinement of removal effort timing. Since the formation of the new waterfall at Piute Farms in 2003, channel catfish and other resident nonnative fish have been the focus of removal actions.
Multiple-pass, capture-recapture sampling was conducted in most (819 river km) warm water reaches of the Green River Basin, Utah and Colorado, to estimate demographic parameters for recruit-sized (400 to 449 mm TL) and adult (> 450 mm TL) Colorado pikeminnow Ptychocheilus lucius. Three or four sampling passes were completed in each year for the Yampa, middle Green, and White River reaches (2000 to 2003), and the Desolation-Gray Canyon and lower Green River reaches (2001 to 2003).
Humpback chub population estimates were determined for Desolation and Gray canyons (Deso/Gray), on the Green River, by conducting multiple pass capture-recapture sampling. Three sampling passes were conducted in 2001 and 2003, and two passes were conducted in 2002 due to low water. In 2003, sampling was moved to the fall to avoid capturing Colorado pikeminnow that use Desolation Canyon for spawning. Twelve sites were sampled throughout the two canyons. Included within these sites, were four long-term sites sampled annually by Utah Division of Wildlife Resources since 1989. Analysis of point estimates generated by capture-recapture data demonstrated that the adult humpback chub population was composed of 1,254 individuals...
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