Laserfiche WebLink
45. <br />Biotic Interactions - 0 <br />Colorado squawfish. <br />o Reproductive success of Colorado squawfish tends to be higher in years of <br />high discharge while introduced species reproductive success tends to be <br />suppressed. <br />Haynes et al. (1985) suggested a negative correlation between high flow <br />years and good reproductive success among introduced species. <br />Channel catfish I I r gunctatus) were reported to be an exception <br />as this exotic species exhibited good reproductive success in high flow <br />years. Catch per unit effort of Colorado squawfish in the Yampa River <br />was reported- to be 800% higher in years where peak flows exceeded <br />20,000 cfs than in years with lesser peak flows. They cautioned that only <br />four years of data were available so conclusions were tentative. Flows of <br />20,000 cfs in the lower Yampa River have a recurrence interval of about <br />20 years, but a long-lived species such as the Colorado squawfish could <br />have adapted to such a flow regime <br />Holden (1980) suggested altered flow regime as a possible limiting factor <br />affecting reproductive success of Colorado squawfish. Competition and <br />predation were suggested as possible factors being affected by changes <br />in the hydrograph. He hypothesized that access to gravel pits may be <br />more favorable to introduced species than to native species if they are a <br />stable lentic environment. 0