3011

• UCREFRP Catalog Number: 3011
• Author: Beamesderfer, R. C. and T. C. Bjornn.
• Title: Habitat Selection, Spawning Behavior and Early Life History of Northern Squawfish with Inferences to Colorado Squawfish.
• USFW Year: 1980.
• USFW - Doc Type: Progress Report,
• Copyright Material: NO

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INTRODUCTION

This report summarizes progress in the study of selected aspects

of the life history and behavior of northern squawfish (Ptych~cheilus

oregonensis) from initiation of the project through September 30~ 1980.

Objectives addressed in this study were chosen after thorough review of

the literature to fill in areas of northern squawfish life history and

behavior where information is lacking and to consider problems analagous

to those of Colorado squawfish which might be useful in explaining past

and present distribution patterns and in preventing further declines in

numbers of that species.

In this report~ each objective is considered separately. Within each

objective, specific objectives are identified, the research rationale and

design is explained briefly, activities undertaken to date are descrioed,

results are summarized and discussed informally and recommendations for

future activities are made.

STUDY AREAS

The St. Joe River (Fig. 1) drains the west slQpe of the Bitterroot

Mountains and empties into the south end of Coeur d'Alene Lake in the

northern panhandle region. of Idaho. Mean annual air temperature in the

region is 8.5 C and annual precipitation averages 77.3 cm (Falter 1969).

Mean annual flow at Calder is 2377 cubic feet per second (USGS 1979)_ The

lower 34 miles of the river, referred to as slackwater, consist of smooth

surfaced water flowing over a coarse silt and sand bottom where average

river depth was 9.0 meters and average width was 80 m (Davis 1961). In

this section the river meanders through a broad, flat valley. Above the

slackwater gradient increases and riffles and long deep pools alternate.