Laserfiche WebLink
1 <br />slow runs, °slacc waters" and eddies, in depths of 0.6 to 1.4 m (2.0 to 4.6 ft) and <br />velocities of 0.03 to 0:33 m/s (0.1 to 1.1 ft/s; Valdez and Masslich 1989). <br />In the upper Colorado River, near Grand Junction, Osmundson and Kaeding (19.89) <br />reported similar habitat use: pools and slow eddies from November through April, runs <br />and pools from July through October,-runs and backwaters during May, and <br />backwaters, eddies, and flooded gravel pits during June. Selection of depths changed <br />seasonally; use of relatively shallow water occurred during spring and use of deeper <br />water during winter. Mean depths were 0.9 to 0.99 m (3.0-3.3 ft) during May and June, <br />1.62 to 1.65 m (5.3-5.4 ft) from August through September, and 1.83 to 2.16 m (6.6-7.1 <br />ft) from November through April (Osmundson and Kaeding 1989). <br />Adult razorback suckers use a great variety of habitats, including lower gradient, low- <br />vetocity riverine sections of canyon-bound areas. The fish also have been tracked <br />moving through whitewater habitats (Tyus and Karp 1990), but spent little time there. <br />There are few historic records of razorback suckers in Grand and Marble canyons of <br />the lower Colorado River, possibly due to lack of historic sampling in these <br />inaccessible whitewater canyons (Minckley et al. 1991). Lanigan and Tyus (1989) <br />suggested that n~zorback sucker distribution in the Green River may be constrained by <br />whitewater canyons that either impede migration or do not have suitable habitat. <br />Although the fish has been extirpated from its historic riverine habitats in the lower <br />16 <br /> <br /> <br /> <br /> <br />s <br /> <br /> <br /> <br /> <br /> <br />a <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />