7159

• UCREFRP Catalog Number: 7159
• Author: Hagen, H. K.
• Title: Progress Report on Ecological and Limnological Studies of the Green River in Dinosaur National Monument.
• USFW Year: 1963.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

At L~ not a single !ish :was-i'ounfi ilp!';p.1kJt~!1,r~ back-breaking
efforts to sein€-._the water. Not a~_!ngle fish appJ~!!:r-~_ci in the poisoned
channeJ..-.of' the stream. This area lias kept under observation until late
afternoon and examined that night and the following day by supervisory
Ranger Forsell l'lho was checking hunters in the area.

TABLE 1. FISH COLLECTIOrffi IN DINOSAUR NATIONAL MONUMENT, OCTOBER 19-21, 1962

Common name

Echo
Park

Island
Park

Flannel-mouth sucker
Channel catfish
Co!9. River sq~sh
Round-tailed chub
Dluehead Mtn. sucker
Colo. mottled sculpin
utah silversides minnOll
Green River Spring dace
Carp
Black bullhead
Fathead minnovT
Total

1

8
2

Castle Split
Park Mountain
12 25
1 .2
2
2 5
lO
It
1
lO3 2
1 36
2
l33 75

l2

2

15
10

11
26

35

Table 2, contrasts the species composition in the section sampled
in 1961 and 1962. The grpatest reduction was at lodore, of 'course, where
no fiGh vere found 50 1962. At Echo Park thcre "Tere oJ~!1_three of the
species found of the eleven recorded in 1962. Pimephales was found in
1962 at Echo Park but not in 1961. Loss in species was great at Island
Park but less severe at Split Hountuin.

Obviously the methods used cannot guarantee that the sampling was
representative of the fish present and that some fish species are not
still in the river. It is certainly hoped that they are. The contrast
between the numbers of fish taken in 1961 and 1962, however, lvas very
apparent to all those who blid participated in both expeditions. In
1961 so many fish "ere taken with less effective equipment and in higher
\-Iaters that no attempt was made to count actual numbers of fish. This
is now regretable in view of the change in 1962. In Echo Park) for
example) the 1961 crew turned up hundreds of fishes in only one "hole"
near the entrance of Pool Creek. In 1962, this hole plus the entire
section of the river produced only twenty-six fish. There is no doubt
that the fish kill in the Monument was very extensive.

A preliminary count of invertebrate organisms taken in 1962 as
compared with 1961 is shown in Table 3. Nore complete data will be
given in the final report but it is interesting to note that the decrease
in bottom organisms was very striking. This is again contrary to what
might be expected had the stream not been polluted. The louer water

= 5 =