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

NORTHERN PIKE-YAtlPA RIVER

LENGTH DISTRIBUTION BY ~I

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Figure 3. Length frequency distribution of Yampa River northern pike by
river mile capture location.

No reproductive success by northern pike was observed in reaches of the
Yampa also inhabited by Colorado squawfish in either 1987 or 1988. In August
and September 1987, a total of nine seine hauls at six sites (including two in
the Juniper reach, three in the Maybell reach, and one in the. Craig reach)
produced no northern pike YOY. In April-June, 1988, at the Lay Creek (RM
88.2) and Little Snake (RM 51.5) confluences where ripe northern pike were
sampled, available immersed vegetation was searched for eggs. Four seine
hauls were also made to sample for pike YOY. Other backwaters which contained
inundated or aquatic vegetation and appeared suitable as nursery habitat such
as Government Bridge (RM 98.7) and Disappointment Draw (RM 45.4) were sampled
with seine or dip net for the presence of northern pike YOY. In August 1988,
three seine hauls were made at suitable sites between Morgan Gulch (RM 103.4)
and Government Bridge. No northern pike eggs or YOY were sampled in any of
these efforts in 1988. During 19 electrofishing efforts in 16 backwaters in
1988, no YOY or juvenile pike were observed. Eight backwaters located at RM
106.7, 113.2, 144.2, 144.6, l45.1, 147.0, 15l.5, and 152.5 were also sampled _
in May 1988, and no YOY or juvenile pike were observed.

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