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

Dissolved oxygen varied from 6.5 p.p.m. to 7.3 p.p.m. The pH was
nearly constant at 7.4 to 7.6. Alkalinit ies shoved the greatest varia-
t ions as would be expected.

Bottoms in this part of the river were mostly of fine sand and silt
and were constantly changing. Aquatic vegetation was absent in the
Lodore area.

Fish were captured in several ways and the pattern of capture: gave
valuable clues as to the position of several species in the stream current.
For example - the "throw" or "set" lines vhich were most effective in
taking large fish indicated the fish were mainly restricted to the shore-
line areas. No fish were taken beyond the third hook on the line.
Coloring of the '%!5ii"iy--tail chubs and other fish gave indication of
approaching spawning periods. Immature insects taken in this area showed
an interesting adaptation to counter the effects of the shifting bottom.
The large majority were found attached to tree limbs and sticks that
were partially submerged in the sand.

July 29 - August 25, 1962

Mr. Banks moved to t.he Ech.Q:p~ar:k area and cont inued to collect
samples and make observations much as those at Lodore. He ventured as
far as possible up the Yampa River in addition to collecting on the Green.
A plankton net was used in the slow moving sections of the streams.

Interesting and valuable observations were made including: time of
insect hatches, rate of drop of river water and related catches of fish;
variations in bottom types in the Yampa and Green Rivers; variations in
amounts of stream vegetation; slightly but constantly cooler water temper-
atures of the Green River; the first observation of a very young carp
(3 inches in length) with a pronounced nuchal hump; many others.

September 3 through September 16, 1962

In anticipation of the upstream rehabilitation project in Wyoming,
utah and parts of Colorado, Mr. Banks moved back to ~r~ to be able
to make detailed observations. He made a number of checks on fish and
invertebrate populations to compare with observations made in July.

When the toxic effects were anticipated at Brown's Park bridge he
journeyed there to watch the de-toxification operation. During the
following several days he intensely studied the stream inside the
boundaries of Dinosaur National Monument. l.fr. Banks collected, identi-
fied and preserved a number of the dead and dying fish. He assisted
Park Service personnel in constructing live-boxes, making chloroform
tests for rotenone and in other ways. After the fish stopped dying he
sampled intensively to determine the results of the escaped poison.
Despite great efforts that had yielded many specimens before he was
ab e to finO. dnlY6nelive fish and this fish a smal:l dace) was in a
smal , shallow-poo . ere It coUld have been isolated
and thus escapedthe effects of the poison.

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