Download or read book Factors Influencing the Distribution of Bull Trout and Westslope Cutthroat Trout West of the Continental Divide in Glacier National Park written by Vincent Stephen D'Angelo and published by . This book was released on 2010 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reported decline of native bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarkii lewisi populations west of the Continental Divide in Glacier National Park (GNP) prompted research to identify critical habitats and investigate factors influencing their distribution and relative abundance. I evaluated the association of six abiotic factors (stream width, elevation, gradient, large woody debris density, pool density, mean August stream temperature) and a biotic factor (the presence of nonnative lake trout, Salvelinus namaycush) with the occurrence and density of bull trout and westslope cutthroat trout in 79 stream reaches in five sub-drainages of the North Fork Flathead River in GNP. Logistic and linear regression models were used to quantify the influence of these independent variables on species occurrence (presence/absence) and density (age-1 or older fish/100m2), and an information theoretic approach (AICc) was used to determine the most plausible combinations of variables in each case. The occurrence of westslope cutthroat trout was negatively associated with the presence of lake trout and positively associated with large woody debris and water temperature. Westslope cutthroat were detected throughout a wide range of water temperatures (8.5-16oC), stream sizes and elevations, but were most abundant in small, complex streams that were not connected to lakes supporting lake trout. Bull trout occurrence was positively related to stream width and negatively related to channel gradient and water temperature. Bull trout were most abundant in narrow (

Download or read book The Present Status and Distribution of the Westslope Cutthroat Trout Salmo Clarki Lewisi East and West of the Contenental Divide in Montana written by George A. Liknes and published by . This book was released on 1984 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exerpt From Abstract: "The distribution and abundance of westslope trout (Salmo clarki lewisi) has drastically declined over its historic range in the last 100 years. Although previous studies in Montana have identified strongholds, the status of westslope cutthroat statewide continued to be an uncertainty. The purpose of this report was to quantitatively determine the present and historic range as well as identify strongholds of genetically pure westlopw cutthroat in Montana... Statewide, 259 lakes contain or are believed to contain westslope cutthroat populations. Six percent are known to contain genetically pure populations. Fifteen of the 16 pure populations are found within Glacier National Park; the other population is located on the Flathead Indian Reservation. Only 4 lakes or reservoirs east of the continental divide were found to contain westslope populations."

Download or read book Influence of Stream Size and Morphology on the Seasonal Distribution and Habitat Use of Resident Bull Trout and Westslope Cutthroat Trout in Western Montana written by Michael J. Jakober and published by . This book was released on 1994 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Demographic and Habitat Requirements for Conservation of Bull Trout written by Bruce E. Rieman and published by . This book was released on 1993 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Abiotic and Biotic Factors on Occurrence of Resident Bull Trout in Fragmented Habitats Western Montana written by Cecil Frank Rich and published by . This book was released on 1996 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factors Influencing Spawning Migration of Bull Trout Salvelinus Confluentus in the North Fork Skokomish River Olympic National Park Washington written by Samuel J. Brenkman and published by . This book was released on 1998 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distribution and life history characteristics of lacustrine-adfluvial bull trout (Salvelinus confluentus) were described in the North Fork Skokomish River Basin (including Lake Cushman, a reservoir) from 1994 to 1996. Day snorkeling was conducted in the river to determine initiation of the bull trout spawning migration, abundance of spawners, and duration of spawning. Declining photoperiod, increased river discharge, and decreased water temperature appeared to influence timing of migration and spawning. Lacustrine-adfluvial bull trout typically entered the North Fork Skokomish River in October although some fish entered as early as May. Mean lengths of spawners consistently increased from June to December 1996, and early migrating bull trout were shorter than those fish that entered after river discharge increased in October. The presence of two phases of the spawning migration may be indicative of two populations spawning in the river. Bull trout spawned between mid-September and December in the river and tributaries after water temperatures declined. All spawning occurred at temperatures less than 7.5°C. Comparisons with studies of other lacustrine-adfiuvial bull trout populations that inhabit river and reservoir complexes suggested that bull trout exhibit specific migratory strategies related to local environmental conditions. In the North Fork Skokomish River, changes in abundance of bull trout, mountain whitefish (Prosopium wilhamsom), cutthroat trout (Oncorhynchus dark), and rainbow trout (Oncorhynchus mykiss) revealed distinct temporal segregation among these species. Olympic National Park, a designated Biosphere Reserve, contains one of the largest remaining areas of relatively pristine habitat in the range of bull trout. Knowledge of responses of bull trout to changes in river discharge and temperature from relatively undisturbed systems, such as the North Fork Skokomish River, may be useful in understanding patterns observed in degraded environments.

Download or read book The Present Status and Distribution of the Westslope Cutthroat Trout Salmo Clarki Lewisi East and West of the Continental Divide in Montana written by George Alton Liknes and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Feasibility Assessment for Translocation of Imperiled Bull Trout Populations in Glacier National Park Montana written by Benjamin Thomas Galloway and published by . This book was released on 2014 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Translocations are becoming an important tool for conservation and recovery of native fishes. However, many translocations have been unsuccessful likely due to inadequate feasibility assessments of abiotic and biotic factors influencing translocation success prior to implementation. This study provides a framework developed to assess the feasibility of translocating threatened bull trout Salvelinus confluentus into novel stream and lake systems in Glacier National Park, Montana (GNP). Populations of bull trout in GNP are at risk of extirpation in several lakes due to the establishment of nonnative invasive lake trout S. namaycush. Drainage-specific translocations of extant bull trout populations have been proposed as a possible management solution to these declines, but the suitability of translocation sites is unknown. This study evaluated the suitability of spawning, rearing, foraging, and overwintering habitats in three isolated headwater stream and lake systems (Logging, Camas, and Lincoln sites) to determine their suitability for bull trout translocation. A scoring framework was developed to compare the suitability of proposed translocation sites based on three major components: potential for the recipient habitat to support a translocation; potential for the translocation to negatively impact native aquatic biota; and ability of within-drainage donor populations to support a translocation. Scoring criteria were developed based on abiotic and biotic characteristics known to influence translocation success, including water temperature, habitat quantity and quality, habitat complexity, species composition, and the possibility of conducting within-drainage translocation. Based on the framework, the Camas site is the most suitable for translocation because it contains physical and biological conditions comparable to other systems supporting bull trout. The Logging site is the second most suitable site for translocation, whereas the Lincoln site is least suitable because it contains a minimal amount of stream habitat (

Download or read book Distribution and Population Characteristics of Lake Trout in Lake McDonald Glacier National Park written by Andrew Martin Dux and published by . This book was released on 2005 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bull trout Salvelinus confluentus have declined since the establishment of nonnative lake trout Salvelinus namaycush in Lake McDonald, Glacier National Park (GNP). In an attempt to prevent further decline of this population, GNP is considering implementing a lake trout suppression program. I used ultrasonic telemetry to examine the spatial and temporal distribution of lake trout and gill nets to evaluate population characteristics and diet. Model simulations were used to predict lake trout responses to varying levels of suppression. I relocated 36 lake trout (508-859 mm total length) 1,137 times from June through November 2003 and March through November 2004. Lake trout had a narrow vertical distribution during all seasons in both 2003 and 2004, rarely occupying depths>30 m. During thermal stratification, lake trout occupied depths in the upper hypolimnion where mean temperature varied from 8-9°C and dissolved oxygen was highest. Lake trout typically were suspended in the water column during all seasons except autumn. When spawning commenced in late-October, lake trout were associated with littoral habitats containing clean cobble and boulder substrates. The lake trout population had a broad age structure and a maximum age of 37 years. Males reached maturity earlier (12 years) than females (15 years), and total annual mortality rate for lake trout ages 8-27 was 13.2%. Growth rates were slow and relative weight values were among the lowest observed for lake trout throughout their range. Food habits were sampled from 254 lake trout, and 95% of the diet by weight consisted of fish prey. Model simulations indicated that substantial population reduction could be achieved with moderate exploitation (20-50%); however, this was more easily achieved as the size at which lake trout could effectively be captured was reduced. Simulations suggested that recruitment could be reduced to a level where adults are not being replaced at low exploitation (10-30%). These data will allow suppression efforts to be focused at times and places that will maximize efficiency, and population simulations suggest that substantial reduction of the lake trout population is feasible. Ultimately, results from this study should promote recovery of bull trout in Lake McDonald.

Download or read book Spawning and Early Life history Characteristics of Bull Trout in a Headwater lake Ecosystem written by Lora Beth Tennant and published by . This book was released on 2010 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bull trout, Salvelinus confluentus, are in decline throughout their native range. Interaction with nonnative species is considered to be one of the drivers of bull trout decline. Bull trout exhibit a variety of life-history strategies and lacustrine-adfluvial bull trout seem to be particularly susceptible to population decline when nonnative lake trout, S. namaycush, invade or are introduced into lakes where bull trout are the dominant salmonid. Quartz Lake in Glacier National Park, Montana, provided a unique opportunity to gather information on the spawning and early life-history characteristics of a bull trout population prior to anticipated declines in bull trout abundance due to lake trout invasion. The objectives of this study were (1) to characterize the spatial and temporal dynamics of bull trout spawning migrations and associate areas of high redd accumulation to abiotic factors, and (2) to quantify the influence of abiotic factors on the distribution of subadult bull trout in tributary streams of Quartz Lake. Stream surveys were conducted to quantify physical habitat characteristics in the study area, backpack electrofishing was used to sample subadult bull trout rearing in lake tributaries, and redd surveys were used to investigate the spatial and temporal trends in the accumulation of bull trout redds. Bull trout redds and subadult bull trout were found throughout the study area; however, bull trout spawning and rearing appeared to be concentrated in lower Quartz Creek. This area was low gradient, and there was a high percent of gravel and cobble substrates. Bull trout spawning began in late September, peaked in early October, and concluded in mid-October. These data provide important information on bull trout life-history in headwater lakes and provide biologists with baseline data that will be useful for assessing the effects of lake trout suppression efforts that began in 2009.

Download or read book A Watershed scale Monitoring Protocol for Bull Trout written by Dan Isaak and published by . This book was released on 2009 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Changes in Distribution of Trout in Great Smoky Mountains National Park 1900 1977 written by George Alan Kelly and published by . This book was released on 1980 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant changes have occurred in the distribution of trout in streams of Great Smoky Mountains National Park since 1900. By the mid-1970's the original range of the native brook trout had been reduced by about 70% and the species was relegated to suboptimal habitat in head water streams. Most of the stream sections lost by brook trout became the territory of the introduced rainbow trout, which in 1977 occupied about 80% of the Park waters. After 1950, brown trout introduced in State waters outside the Park established reproducing populations in some 50 miles of stream formerly occupied only by rainbow trout. If current trends continue, the recovery of brook trout in Park water may be difficult, if not impossible, and brown trout may occupy much of the territory now held by rainbow trout.

Download or read book Distribution and Habitat Use of Bull Trout Following the Removal of Nonnative Brook Trout written by Dirk Renner and published by . This book was released on 2005 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invasion by nonnative brook trout (Salvelinus fontinalis) often results in replacement of bull trout (Salvelinus confluentus) in western North America, but the causal mechanisms are not well understood. Removal of brook trout from 1992 to 2000 from Sun Creek in southern Oregon, provided an opportunity to investigate the changes in distribution and abundance of bull trout. This study investigated bull trout distribution over from 1994 to 2003, during and following the extirpation of brook trout in 2000. In 2001 over, 8 km of contiguous stream habitat was examined to investigate bull trout habitat utilization. Bull trout abundance increased almost 300% after the removal of brook trout; however, bull trout distribution did not shift either upstream or downstream into habitat previously occupied by brook trout. This finding suggested that the occupied habitat was either critical for bull trout persistence or that factors restricted dispersal. Temperature did not appear to limit bull trout distribution remaining below 17°C with averages less than 10°C throughout Sun Creek. The downstream distribution of bull trout coincided with a point source increase of turbidity. In regions of the stream where turbidity was low bull trout abundance was positively associated with deep pools, higher average temperatures, and correlated with high densities of springs. The results of this study suggest that brook trout did not displace bull trout, underscoring the importance that point source disturbances (i.e. turbidity) can have on trout distributions. These findings reiterate the value of sampling contiguous streams as a means to identifying factors influencing trout distribution throughout a stream system.

Download or read book Conservation Assessment for Inland Cutthroat Trout written by and published by . This book was released on 1995 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book South Fork Flathead Watershed Westslope Cutthroat Trout Conservation Program written by and published by . This book was released on 2005 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Movement Distribution and Resource Use of Westslope Cutthroat Trout in the South Fork Clearwater River Basin written by Marika E. Dobos and published by . This book was released on 2015 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although many Westslope Cutthroat Trout Oncorhynchus clarki lewisi populations in Idaho are robust and stable, others are depressed. In some systems, such as the South Fork Clearwater River (SFCR) system, environmental conditions (e.g., summer temperatures) are hypothesized to limit populations of Westslope Cutthroat Trout. Radiotelemetry and snorkeling methods were used to describe movement, distribution, and habitat use of Westslope Cutthroat Trout in the SFCR in 2013 and 2014. Sixty-six tags were implanted into fish (155–405 mm). Sedentary and mobile summer movement patterns of Westslope Cutthroat Trout were observed. Sixty-two sites were snorkeled along the mainstem SFCR from 5–14 August 2014 to better describe the distribution of Westslope Cutthroat Trout. Twenty-three Westslope Cutthroat Trout were observed in 12 sites and at low density (mean ± SD; 0.0003 ± 0.0008 fish/m2 ). Results indicate that summer temperature was the primary factor limiting the distribution of Westslope Cutthroat Trout in the system.

Download or read book Bull Trout Distribution and Abundance in the Waters on and Bordering the Warm Springs Reservation written by and published by . This book was released on 2003 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The range of bull trout (Salvelinus confluentus) in the Deschutes River basin has decreased from historic levels due to many factors including dam construction, habitat degradation, brook trout introduction and eradication efforts. While the bull trout population appears to be healthy in the Metolius River-Lake Billy Chinook system they have been largely extirpated from the upper Deschutes River (Buchanan et al. 1997). Little was known about bull trout in the lower Deschutes basin until BPA funded project No. 9405400 began during 1998. In this progress report we describe the findings to date from this multi-year study aimed at determining the life history, habitat needs and limiting factors of bull trout in the lower Deschutes subbasin. Juvenile bull trout and brook trout (Salvelinus fontinalis) relative abundance has been assessed in the Warm Springs River and Shitike Creek since 1999. In the Warm Springs R. the relative densities of juvenile bull trout and brook trout were .003 fish/m2 and .001 fish/m2 respectively during 2002. These densities were the lowest recorded in the Warm Springs River during the period of study. In Shitike Cr. the relative densities of juvenile bull trout and brook trout were .025 fish/m2 and .01 fish/m2 respectively during 2002. The utility of using index reaches to monitor trends in juvenile bull trout and brook trout relative abundance in the Warm Springs R. has been assessed since 1999. During 2002 the mean relative densities of juvenile bull trout within the 2.4 km study area was higher than what was observed in four index reaches. However, the mean relative densities of brook trout was slightly higher in the index reaches than what was observed in the 2.4 km study area. Habitat use by both juvenile bull trout and brook trout was determined in the Warm Springs R. Juvenile bull trout and brook trout were most abundant in pools and glides. However pools and glides comprised less than 20% of the available habitat in the study area during 2002. Multiple-pass spawning ground surveys were conducted during late August through October in the Warm Springs R. and Shitike Cr. during 2002. One-hundred and thirteen (113) redds were enumerated in the Warm Springs R. and 204 redds were found in Shitike Cr. The number of redds enumerated in both the Warm Springs R. and Shitike Cr. were the most redds observed since surveys began in 1998. Spatial and temporal distribution in spawning within the Warm Springs R. and Shitike Cr. is discussed. Juvenile emigration has been monitored in Shitike Creek since 1996. A total of 312 juveniles were estimated to have emigrated from Shitike Cr. during the spring, 2002. Adult escapement was monitored in the Warm Springs R. and Shitike Cr. Thirty adults were recorded at the Warm Springs National Fish Hatchery weir during 2002. This was the highest number of spawning adults recorded to date. A weir equipped with an underwater video camera near the spawning grounds was operated in the Warm Springs R. Thirty-one adults were recorded at the weir in day counts. The adult trap in Shitike Cr. was unsuccessful in capturing adult bull trout during 2002 due to damage from a spring high water event. Thermographs were placed throughout Warm Springs R. and Shitike Cr. to monitor water temperatures during bull trout migration, holding and spawning/rearing periods. During 1999-2002 water temperatures ranged from 11.8-15.4 C near the mouths during adult migration; 11.4-14.6 C during pre-spawning holding; and 6.5-8.4 C during adult spawning and juvenile rearing.