Life histories of westslope cutthroat and bull trout in the upper Flathead River basin, Montana /

Abstract

Mean densities of bull trout estimated from electrofishing in the Flathead and the Toboggan, MacKenzie and Wigwam drainages of British Columbia 3 2 19 Mean densities of age 0, age I, age II, age III, all bull trout and age I and older bull trout in pools, runs, riffles and pocketwater of the upper Flathead River basin (1979-1981) .... 33 20 Flow pattern or habitat units used by juvenile bull trout and Dolly Varden in streams of Maitana, British Columbia and Alaska. 3 3 21 Cover used by juvenile bull trout and Dolly Varden in streams of Alaska, Montana, and British Columbia 3 5 22 Depth and velocity used by juvenile bull trout in the Flathead and general depth and velocity measures of juvaiile bull trout in streams of British Columbia, adopted from Griffith 1979. .. vi i 36 LIST OF TABLES (Cont.) TABLE P^E 23 Substrate asscx:iated with juvenile bull trout in British Columbia and the Flathead 3 7 24 Percent of age I, II, III, and IV bull trout emigrating from tributary streams 3 9 25 Number of days trapping occurred, number of juvenile bull trout passed downstream through traps, and number of trapped juvenile bull trout per trap day by month from North Fork tributaries during 1976 to 1980 and Middle Fork tributaries during 1981.. . 39 26 Characteristics of bull trout spawning, including time of year, size of spawner, sex ratio and fecundity observed in river drainages of Montana, Idaho and British Coluik^ia 4 6 27 Characteristics of bull trout redds including redd size (disturbed area) , depth of egg deposition, water depth, velocity and streambed conposition observed in river drainages of Montana, Idaho and British Columbia 48 4 5 X LIST OF APPENDICES APPENDIX PAGE A Summary of results for downstream trapping of juvenile westslope cutthroat and bull trout in upper Flathead River tributaries from 1976 to 1981 ai B Sumnary of tag return information illustrating movement of westslope cutthroat and bull trout in the upper Flathead River Basin b l C Age-growth information for westslope cutthroat and bull trout in the upper Flathead River drainage ci xi

Bull Trout Distribution and Abundance in the Waters on and Bordering the Warm Springs Indian Reservation, 2000 Annual Report.

“…Spawning occurs during September followed by a rapid downstream migration. Rapid post-spawning downstream migration has been noted in other fluvial bull trout populations (McLeod and Clayton 1994;Oliver 1979;and Shepard et al 1984 Fluvial Deschutes R. bull trout demonstrated an affinity for deep pools and glides. They occupied deep pools and glides in the Deschutes R. during the fall, winter and early spring.…”

“…Adults return to their natal streams to spawn beginning at age IV (Pratt, 1992, Shepard et al, 1984. Adult immigration into the Warm Springs R. at the WSNFH was monitored by U.S.…”

Coeur d'Alene Tribal Production Facility, Volume III of III, 2002-2003 Progress Report.

“…Of the 6 sites where high levels of small or coarse fines were recorded, only the sites located in the mainstem of Lake Creek showed supporting evidence for low recruitment. The other sites had juvenile and adults densities (range = 12.4 -33.8/100 square meters) that were notably higher than the average density (9.2/100 square meters) reported for seven other westslope cutthroat trout populations in Idaho and Montana (Shepard et al 1984b, Ireland 1993. Several factors may buffer the effects of high sedimentation of redds.…”

“…In Benewah Creek, four tributaries, comprising 32% of the usable stream area in the watershed, have cutthroat trout densities that are notably higher than the average density (9.2/100 square meters) reported for seven other westslope cutthroat trout populations in Idaho and Montana (Shepard et al 1984b, Ireland 1993. In Lake Creek, 41% of the perennial stream area supports higher than average densities, while 26% of the stream area in Evans Creek supports higher than average densities.…”

A Fine-scale Assessment of Using Barriers to Conserve Native Stream Salmonids: A Case Study in Akokala Creek, Glacier National Park, USA

“…Westslope cutthroat trout likely exhibit migratory (i.e., adfluvial and fluvial) and resident life histories in the Akokala watershed [32], and the population is genetically divergent from other populations in the basin [28]. Resident fish remain in their natal stream throughout their lives, whereas migratory westslope cutthroat trout rear in their natal stream for 1-4 years and then migrate downstream to mainstem rivers (fluvial) or Flathead Lake (adfluvial) to rear before returning to their natal stream to spawn [20,33]. Migratory westslope cutthroat trout radiotagged in the Flathead River have been documented spawning in the lower portion of the watershed [32].…”