7402

• UCREFRP Catalog Number: 7402
• Author: Nesler, T. P.
• Title: Aquatic Nongame Research, Endangered Fishes Investigations.
• USFW Year: 1989.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

Table 6. Occurrences of northern pike, channel catfish, and Colorado
squawfish and species combinations observed in sampling efforts in
spring backwaters and fall-sUmmer pools and eddys in the Yampa
River, 1987-1988.

Species
combinations

Spring
Backwaters

Fall-Summer
Pools-Eddys

CS/NP together
CS/CC together
CS alone
NP alone
CC alone
CS/NP/eC together
NP/CC together
None of the above

2
2
3
4
o
5
2
4

6
3
5
4
o
1
1
o

aCS=Colorado squawfish, NP=northern pike, CC=channel catfish

Including northern pike, channel catfish, and Colorado squawfish, six
other species were collected during backwater, pool, eddy, and embayment
sampling. Most commonly observed in backwater "block and shock" sampling were
carp, flannelmouth sucker, and roundtail chub. Roundtail chub were also
captured frequently during netting and angling in mainchannel pools, eddys,
and embayments. Bluehead sucker and white sucker were captured only
occasionally in backwaters. Black bullhead (Ictalurus melas) were captured in
two locations only. One was taken in a large isolated pool at RM 94.7. One
was captured, and 10-12 smaller bullhead were observed during two separate
sampling efforts at one of the backwaters located at RM 51.5 above the Little
Snake confluence.

DISCUSSION

Preliminary analyses of the northern pike data suggest the Yampa River
population is relatively small, and comprised primarily of adult fish within
the reaches inhabited by Colorado squawfish (Juniper Springs and downstream).
Indices of condition in conjunctio~ with visual evidence of physical injury
further suggest northern pike are not particularly well-adapted to the flow

~

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