8290

• UCREFRP Catalog Number: 8290
• Author: Day, K. S. and C. Crosby.
• Title: An Assessment of Young-of-the-Year Colorado Squawfish ‎(Ptychocheilus lucius)‎ Use of Backwater Habitats in the Green River, Utah.
• USFW Year: 1997.
• USFW - Doc Type: FG-33,
• Copyright Material: NO

STIIDY AREA
Sampling was conducted in a 16.1 km reach of the Green River wholly with
boundaries of Ouray National Wildlife Refuge (NWR) (Figure 1). The reach incl
riverine habitat between the upstream portion of Leota Bottom (river kilometer
the inlet to Woods Bottom (RK 405.5). This portion of the Green River is char
extremely low gradient and slow flow. River bed sediments consist of sand, mu
Eleven island/sandbar complexes and eleven perennial sandbar complexes ars pre
reach. Many migrating sandbars develop each year. Deposition and erosion of
form numerous backwater habitats in this reach. Backwaters are formed most co
through sand wave migration and scouring.
Habitat conditions in this reach are determined by annual flows. Deposi
spring peak flows is determined largely by output of the Yampa River and Flami
Spring high flows of up to 23,000 cfs were observed. Sculpting of aggraded ma
upon summer and winter flows. Summer flows during the study were fairly stabl
depending upon the year, were between 1400 cfs and 2000 cfs. Winter flows var
high as 4000 cfs. Main channel temperatures varied with annual weather Condit
seasonality. Spring temperatures from 4°C to 12°C, summer temperatures from 2
and fall temperatures from 10°C to 20°C were observed.
Islands and shoreline areas are dominated by cottonwood (Populus freemon
dense understory of salt cedar (Tamarix ramosissima), willow (Sa1ix exigua, S.
an-ygdaloides) and skunkbush sumac (Rhus trilobata). Forb and grass communitie