7424

• UCREFRP Catalog Number: 7424
• Author: National Research Council
• Title: Editor
• USFW Year: Series
• USFW - Doc Type: 1987
• Copyright Material: YES

-6-
fish feeding habits. The interpretation of these
data provides numerous useful insights concerning
the mechanisms that regulate the fish resources of
the Colorado River.
The new information improves our understanding of
the physical limitations on individual fish species
in the Colorado River. However, the data base and
data analysis need to be expanded to support
predictive modeling of critical habitat space for
fish species in both adult and larval stages. This
requires integration of research efforts with
studies focused on sediment deposition, particle
size distribution, and invertebrate and algal
productivity in the river downstream from Glen
Canyon.
The Department of the Interior should
• support a monitoring program to evaluate
future operations in the context of a Colorado
River ecosystem model with priority on sediments
and aquatic biota components
• evaluate the quality of the water that is
released or could be released at different levels
from Lake Powell, e.g., temperature, nutrients,
particulate organic materials, and zooplankton
• include algal and invertebrate productivity in
future aquatic study
• perform focused studies on sediment movement
and deposition in reaches between the dam and Lake
Mead
• develop predictive, process-oriented mociels to
understand sediments, water temperature, nutrient
concentrations, and economics of power produc:tion
Terrestrial Biology
The terrestrial researchers were faced with the
difficult task of collecting enough data in a short
period of time, and under conditions for which they
had not planned, to be able to offer suggestions
for river management. This component of the GCES
report suffers from a failure to link riverine