Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; White River Bull Trout Enumeration Project Summary, Progress Report 2003.

Cope, R.

United States. Bonneville Power Administration.

关键词: Bonneville Power Administration;    Management;    Adults;    White River;    Habitat;   

DOI  :  10.2172/963101
RP-ID  :  DOE/BP-00005672-7
RP-ID  :  5672
RP-ID  :  963101

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report summarizes the first year of a three-year bull trout (Salvelinus confluentus) enumeration project on the White River and is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. The White River has been identified as an important bull trout spawning tributary of the upper Kootenay River in southeastern British Columbia. The objective was to collect information on the returning adult spawning population to the White River through the use of a fish fence and traps, and to conduct redd surveys at the conclusion of spawning to provide an index of spawning escapement and distribution. The fence was installed on September 9th, 2003 and was operated continuously (i.e. no high-water or breaching events) until the fence was removed on October 9th, 2003. Estimation of the spawning population of White River bull trout was incomplete. This was due to a larger and more protracted out-migration than expected. As a result, the bull trout spawning population of the White River was estimated to be somewhere above 899 fish. In comparison, this represents approximately one third the population estimate of the 2003 Wigwam River bull trout spawning population. Based on redd index data, the number of bull trout per redd was over twice that of the Wigwam River or Skookumchuck Creek. This was expected as the index sites on the Wigwam River and Skookumchuck Creek cover the majority of the spawning area. This is not true on the White River. From previous redd counts, it is known that there are approximately twice as many redds in Blackfoot Creek as there are in the index site. Additionally, given the large size of the White River watershed and in particular, the large number of tributaries, there is a high likelihood that important bull trout spawning areas remain unidentified. Both floy tag and radio-telemetry data for the White River bull trout have identified extensive life history migrations. Similar data for the Wigwam River and Skookumchuck Creek populations illustrate there is considerable overlap and mixing among these three local populations within their over-wintering and feeding habitat. The upper Kootenay River, Lake Koocanusa and the lower Bull River provide overwintering and feeding habitat for the White River, Skookumchuck Creek and Wigwam River bull trout. Recommendations to improve escapement estimates and spawning distribution are provided. An accurate population estimate is especially important to provide baseline for any potential impacts due to wildfire and subsequent salvage logging that is currently underway immediately adjacent to and upstream of important spawning and rearing habitat in the Middlefork of the White River. Identification of important spawning habitat is important to meet management objectives for the White River.