8250

• UCREFRP Catalog Number: 8250
• Author: Lamarra, V. A.
• Title: Longitudinal Variation in the Trophic Structure of the Upper Colorado River.
• USFW Year: 1999.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

The D50 and D16 values for the stratum sampled in the Gunnison River were not
significantly different from the Colorado River for each habitat type on respective sample
dates. The D16 values in the runs do reflect the changes noted in the size distributions
(Figure 16).
COLORADO RIVER-RIFFLES COLORADO RIVER-RUNS
Mean Particle Diameter: D50 Mean Particle Diameter: D50
200 200
-

150 ..................................... . .... - ............. .._....... .._._...........

- -

150
....__
......... ..__..... . - .....................
.........
E

100
....._
... ._ •___ _ _ __...._

..I ..
E
E
d 100 .........

.........
a
a
.
_. .... ... -__
50 -. .............. ................. ____..- ........ 50 _ ............. ...._.
_-_.__ .......... ..__
•
0 0
Sprig 1994 Fall 1994 Spring 1995 Fall 1995 Sprig 1994 Fall 1994 Spring 1995 Fail 1995
PERIOD PERIOD
GUNNISON RIVER-RIFFLES GUNNISON RIVER-RUNS
Mean Particle Diameter: D50 Mean Particle Diameter: D50
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150 150 i_ ...... ... -
E .... ......
...._ E '. __ ...._
.
E
G 700
......... ....
..... _...- E
$i 100 .........
........ _
." _ __.
... .....

D
0
Spring 1901 Fall 1994 Spring 1995 Fall 1995 Spring 1991 Fall 1994 Spring 1995 Fall 1995
PERIOD PERIOD
Figure 17. The seasonal distribution of D50 subst
Gunnison River (below).
;s and runs in the Colorado River (above) and the
COLORADO RIVER-RIFFLES COLORADO RIVER-RUNS
Mean Particle Diameter: D16 Mean Particle Diameter: D16
100 109

75 - _- .........

___

75 ..... ..................... . _ .._..... .........

.___...
- ......

c 50
a 0
50
__..

25 .... '... - .... ...._ ...... 25 ...... .
_
-
0 0
Sprig 1884 Fall 1991 Spring 1995 Fall 1995 Spring 1894 Fall 1994 Spring 1995 Fep 1995
PERIOD PERIOD
GUNNISON RIVER-RIFFLES GUNNISON RIVER-RUNS
Mean Particle Diameter: D16 Mean Particle Diameter: D16
190 100
75 75 ...._... ___.....
E ......... .____ - .._ ... ........... . _ .. ...... ......... E

0
w
a
25 .......... ........ __.:.... ......- 25 ........'.-.... - ................ ... __•_ -- .._.. .......... ..._...
•
0 0
Spring 1994 Fail 1984 Spring 1995 Fail 1995 Spring 1994 Fail 1994 Sprang 199: Fall 1985
PERIOD PERIOD
Figure 18. The seasonal distribution of D16 substrate sizes for riffles and runs in the Colorado River (above) and the
Gunnison River (below).
18