WSP01587

• File Number: 8220.101.17
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 7/1/1998
• Author: Valdez/et al.
• Title: The Aquatic Ecosystem of the Colorado River in Grand Canyon - Grand Canyon Data Integration Project - Synthesis Report
• Water Supply Pro - Doc Type: Report/Study

AqllQtic Ecosystem of the Colorado River in Grand Canyon

LIST OF FIGURES (Continued)

Figure 16. Chronology of relative abundance offish species in the Colorado River in Grand
Canyon, 1800-1997 ................................................... 51
Figure 17. Distribution of fishes in Glen and Grand Canyons, 1990-1991 ................. 55
Figure 18. Locations of nine aggregations of humpback chub in the Colorado River through
Glen and Grand Canyons. Percentage of total captures are indicated for

1990-1993 .......................................................... 59
Figure 19. Water velocity ranges in nearshore habitat types and average and maximum velocity
preferences ofYOY and juvenile humpback chub ........................... 73
Figure 20. Graph showing guild box with respect to spatial fidelity, feeding strategy, and
temperature preference for the eight native species and eleven principal non-native
species of tile Colorado River in Grand Canyon ............................ 133
Figure 21. Spawning temperature for Colorado River fishes ........................... 135
Figure 22. Egg-hatching temperature for Colorado River fishes ........................ 135
Figure 23. Lethal and optimum growth temperature for Colorado River fishes. . . . . . . . . . . .. 136
Figure 24. Number of species, species diversity, and biomass of native and non-native fish
species by geomorphic reach from Lees Ferry to Dimnond Creek .............. 137
Figure 25. LCR iD110w at 9,200 to 9,600 efs mainstem discharge ....................... 155
Figure 26. LCR inflow at 12,130 to 12,809 efs mainstem discharge ..................... 157
Figure 27. LCR iD110w at 17,470 to 17,798 efsmainstem discharge..................... 159
Figure 28. Three flow alternatives developed by Project Workshop participants, compared to
the Seasonally Adjusted Steady Flow alternative (SASF), which served IS the model
for CApdiwental steady flow recommended by FWS in the GCDEIS Biological

Opinion. .......................:................................... 197

vi