7804

• UCREFRP Catalog Number: 7804
• Author: Hagan, H. K. and J. E. Banks.
• Title: An Ecological And Limnological Study of the Green River in Dinosaur National Monument.
• USFW Year: 1963.
• USFW - Doc Type: \
• Copyright Material: NO

T.A13IE 1. SECCHI DISC VISD3n.ITY AT ISlAND PARK, SEPrEl4BER-
oc'rOmm" 1962.

Date Depth of visibility in inches

September 23
25
26
28
29
30
October 28

t
2
4
6
9-3/4
l~t

to cling to bits of brush and debris sticking up trom the bottom sands and
sUt 18a noticeable example ot insect adaptability. With the fishes" the
extreme nuchal hump" the enlarged fins and the lack or reduction in scales.
ot the Gila Cypha and others&re examples at adaptations :to current a.n:d
heav,- turbidity.

!'!!!. ~ populations

Sampling at the fish populations was obviously' prejudiced because of
the sreat difficulty in gett1na into the steep canyon areas. Valuable col-
1ec:tiona should be possible in the summer of 19631 and up until such tiDe
that the Flaming Gor~e Reservoir is filled. It is sincerely hoped that
plans have been made to do this.

1't is interesting to note that in the Lodore area ME-. 13anks was able
to distinguish what he considered to be distinct dU'ferences between the
bony taU. ed chub Gila robusta ele~s and the round taUed chub GUa
robust. robusta. The round taUe chubs 'rere taken only from the slow
current areas near the end of the sandbar 1 vest of the Lodore Ranger
Station. He found the bony tailed chub in the taster waters of the narrow
chazmels with only an occasional fish in the slower waters. Also of
interest is his report of red to orange markings on the sides of the bony
taU :Lnmid-July. This marking is associated with spawning in the male
tish and reportedly does not last for a. . long period of time as it m1eht in
otber. spec iea. The bony taU is reported to spawn in Lake lot>have on the
lover Colorado River in }.~.

The exotic carp ~rinUS carpio '1ere taken in all sections of the
lb1\D1ent throughout t e summer and ill the autumn. Despite the fact that
1ih1a fish is usually considered a fish of slow vaters and especially lakes
8ZI4. reservoirs, it seems to have expanded into most niches of the turbulent
Green River. These fish were found entering the upper sections of Jones
Creek in Whirlpool Canyonl the only real trout habitat in the ~nument.
l"t is very significant to note that one carp with a very pronounced nuchal.
huIrp' was found dead in a swift water section of Lodere Canyon near Pot Creek.

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