8214

• UCREFRP Catalog Number: 8214
• Author: Modde, T., D. Irving and R. Anderson.
• Title: Habitat Availability and Habitat Use of Endangered Fishes in the Yampa River during Baseflow Periods.
• USFW Year: 1997.
• USFW - Doc Type: Vernal, Utah and Grand Junction, Colorado.
• Copyright Material: NO

Maybell Gage Fall Hydrograph
1996 & Exceedence Flows (1916-1996)

800

700

V'

600

',^"

'/

1\ v'

.........500
l/l
--
U
-----400
~
o
u: 300

\.,

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, '-"',J"./',

200

100

o 08id, 08id~

. 0'811' .

'oans ' o9i02

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80% _.'m 50%-

20%

1 9961

Figure 6. 1996 fall hydro graph for the Yampa River, Maybell gage.

channel catfish (predators and competitors) were also monitored to define their range of
movement both in and above Yampa Canyon. In addition, in 1997 movements of postspawning
Colorado squawfish will be monitored as they pass through Cross Mountain Canyon and the
Patrick Sweeney Diversion area to record flows fish can negotiate these potential barriers.

i\ total of thirty fish were implanted with radio transmitters in the Yampa River in the
summer of 1996. Of these 30 fish, ten were Colorado squawfish (5 in the lower canyon area and
5 in the upper river reach), 10 were channel catfish (5 in the lower reach and 5 in the upper
reach), five were Northern pike (upper reach) and five were humpback chub (lower reach).
Colorado squawfish, channel catfish, and Northern pike were implanted with a 36-month radio
transmitter (18 g). Humpback chub were implanted with a 6-month (6 g) transmitter because of
their small body cavity and lower body weight. Radio transmitters were implanted during the
months of July and August. Fish in the upper study reach were collected by both angling and
clectrofishing gear and fish in the lower study reach were collected solely by angling. Weekly
aerial surveys of all fish implanted was conducted between 5 August and 20 September 1996. In
addition, another aerial flight was made on 29 October 1996 in an attempt to determine if
implanted fi sh migrated to different locations to overwinter. Seasonal movement of fish was
compared with flow changes in the river.

in Clddition to the aerial surveys, attempts were made to monitor each Colorado squawfish
and humpback chub every two hours through a 24 hr period Boats or wfts equipped with whip
antennas \\ere used to locate fish and exact locations were determined using directional antennas.

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