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 4. Frequency of habitat use by northern pike based on radio-tracking
observations and gear sampling in the Yampa River, 1986-1989.
Habitat Pre- Base Winter Total Gear
type runoff Runoff flow ice-on No. sampling
MCBA 1 0 4 l6 21 29
SCBA 2 0 0 0 2 9
TSBA 3 2 0 0 5 17
............... -........................................................................................................... --........................................................................
MCPO 2 0 16 24 42 30
SCPO 0 0 0 0 0 1
MCED 3 2 4 4 13 13
MCEM 2 0 0 0 2 2

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MCRU
MCSH
SCSH

o
2
1

o
o
o

5
1
o

3
3
o

8
6
1

1
1
4

..................................................................................................................................... --......................................................
--......

TOTAL

l6

4

30

50

100

107

MC=mainchannel, SC=side channel, TS=tributary stream, BA=backwater, PO=pool,
ED=eddy, EM=embayment, RU=run, SH=shoreline

In general, trends apparent in pike habitat use were indicative of time of
sampling, habitat availability, and species behavior (Table 4). Sampling was
conducted predominately in backwaters during pre-runoff and runoff periods due
to the lack of-pike obtainable during standardized spring shoreline
electrofishing. Sampling during baseflow was conducted primarily to obtain
pike adults for radio-tracking implantation. Low flow habitat was restricted
to pools and eddys. These conditions are reflected in the pike numbers
captured by habitat type during "gear sampling" with all but six pike captured
in backwater or pool-eddy type habitat. Habitat use observations of the
radio-implanted pike, however, verify this to be a species' preference for
low-velocity habitat throughout the year with 85% of the contacts occurring in
backwater and pool habitat.
On a seasonal basis, contact data is presently biased toward base flow and
winter seasons since pike were radio tracked only once during pre-runoff and
runoff seasons. During the baseflow period of August through October, and the

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