7870 - Laserfiche WebLink

Home Browse Search

Biological Control. Red shiner are vulnerable to fish predation. Stocking Colorado squawfish (a piscivore) to supplement existing wild stocks could additionally facilitate reducing numbers of nonnative fishes, including red shiner. Physicochemical Manipulations.-Correlative evidence has demonstrated that relative abundance of red shiner is negatively affected by high river discharges and associated lower water temperatures, suggesting that management of flow regimes to approximate natural hydrographs and periodically provide above-average magnitudes in spring and summer discharges would suppress abundance of red shiner. However, cause and effect relationships need to be determined. Common Carp Cyprinus carpio Native Distribution: Temperate regions of Europe and Asia (Lee et al. 1980). Distribution and Status in Upper Colorado River Basin: First introduced into the United States in the mid-late 1800's to serve as a food fish. Today, the species is found in warm waters throughout Canada and the United States. First introduced into Colorado in 1879 (wiltzius 19811 and into Utah by 1881 [Sigler 19581; introduction of common carp into the UCRB probably occurred shortly after its initial introduction into Colorado and Utah. Common carp is now common or abundant throughout the upper basin (Tyus et al. 1982; Nelson et al. 19951. In the upper basin, common carp are locally abundant in sheltered habitats, particularly in impoundments, backwaters, shorelines, and along sand-silt, tamarisk-lined banks [Valdez 1990]. In a survey of CRIB researchers, common carp ranked fourth on a list of 28 nonnative fish species considered to adversely impact native fishes of the CRB and the southwestern United States. Suspected impacts included predation on larvae of all native fishes, especially Colorado squawfish and razorback sucker, and competitive interactions with all native fishes, especially roundtail chub, Colorado squawfish, bluehead sucker, flannelmouth sucker and June sucker Chasmistes liorus mictus. Habitat alteration caused by activities of common carp was also listed as a possible impact [Hawkins and Nesler 1991]. 42