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 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 General Technical Report RMRS written by and published by . This book was released on 1998 with total page 842 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Bull Trout Life History Genetics Habitat Needs and Limiting Factors in Central and Northeast Oregon Annual Report 1996 written by and published by . This book was released on 1997 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is part of a multi-year research project studying aspects of bull trout life history, ecology and genetics. This report covers the activities of the project in 1996. Results and analysis are presented in the following five areas: (1) analysis of the genetic structure of Oregon bull trout populations; (2) distribution and habitat use of bull trout and brook trout in streams containing both species; (3) bull trout spawning surveys; (4) summary and analysis of historical juvenile bull trout downstream migrant trap catches in the Grande Ronde basin; and (5) food habits and feeding behavior of bull trout alone and in sympatry with brook trout.

Download or read book Strategies for Conserving Native Salmonid Populations at Risk from Nonnative Fish Invasions written by Kurt D. Fausch and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Native salmonid populations in the inland West are often restricted to small isolated habitats at risk from invasion by nonnative salmonids. However, further isolating these populations using barriers to prevent invasions can increase their extinction risk. This monograph reviews the state of knowledge about this tradeoff between invasion and isolation. We present a conceptual framework to guide analysis, focusing on four main questions concerning conservation value, vulnerability to invasion, persistence given isolation, and priorities when conserving multiple populations. Two examples illustrate use of the framework, and a final section discusses opportunities for making strategic decisions when faced with the invasion-isolation tradeoff.

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.

Download or read book Bull Trout Distribution and Abundance in the Waters on and Bordering the Warm Springs Indian Reservation 2001 Annual Report written by and published by . This book was released on 2002 with total page 41 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 stable 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 from the fourth year (2001) of the 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 was assessed in the Warm Springs River and Shitike Creek by night snorkeling. In the Warm Springs R. juvenile bull trout were slightly more numerous than brook trout, however, both were found in low densities. Relative densities of both species were the lowest observed since surveys began in 1999. Relative densities of juvenile bull trout and brook trout increased in Shitike Cr. Juvenile bull trout vastly out numbered brook trout in Shitike Cr. The utility of using index reaches to monitor trends in juvenile bull trout and brook trout relative abundance was assessed in the Warm Springs R. for the third year. Mean relative densities of juvenile bull trout within the index reaches was slightly higher than what was observed in the 2.4 km control reach. However, the mean relative density of brook trout in the 2.4 km control reach was slightly higher than what was observed in within the index reaches. Habitat use by both juvenile bull trout and brook trout was determined in the Warm Springs R. Juvenile bull trout and brook trout occupied pools more frequently than glides, riffles and rapids. However, pools accounted for only a small percentage of the total habitat. Multiple pass spawning ground surveys were conducted during late August through October in the Warm Springs R. and Shitike Cr. The number of redds enumerated in the Warm Springs R. declined substantially from 1998-2000 observations. Total redds recorded in Shitike Cr. was higher than 2000, but fewer than observed in 1998-1999. Spatial and temporal distribution in spawning within Warm Springs R. and Shitike Cr. is discussed. Juvenile emigration was monitored in Shitike Cr. The number of emigrants was the highest recorded since 1996. As in past years both a spring and fall migration period was observed. Adult escapement was monitored in the Warm Spring R. and Shitike Cr. The number of adults recorded passing the Warm Springs National Fish Hatchery weir was the second highest recorded since 1995. An adult trap was successfully operated in Shitike Cr. Eighty adult bull trout were enumerated during 2001.

Download or read book Bull Trout Distribution and Habitat Use in the Weiser River Drainage Idaho written by Susan B. Adams and published by . This book was released on 1994 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Feeding Behavior and Diet of Native Bull Trout Salvelinus Confluentus and Introduced Brook Trout S Fontinalis in Two Eastern Oregon Streams written by Stephanie L. Gunckel and published by . This book was released on 2000 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the greatest threats to native bull trout Salvelinus confluentus populations is the presence of non-native brook trout S. fontinalis. This study, conducted in two second-order Eastern Oregon streams, investigates the effect of brook trout on the feeding behavior arid diet of bull trout. Feeding behavior, microhabitat use, and agonistic interactions were examined in a controlled in-stream experiment where twenty enclosures were randomly assigned one of three treatments: two bull trout, four bull trout, or a mix of two bull trout and two brook trout. Results provide little evidence of a niche shift for bull trout in the presence of brook trout or of resource partitioning between sympatric bull trout and brook trout. All fish held focal feeding points in similar microhabitats and fed primarily from the water column. Brook trout showed the greatest growth, were highly aggressive, and consistently dominated bull trout of equal size. Examination of stomach contents revealed allopatric bull trout, sympatric bull and brook trout fed primarily on larvae of Ephemeroptera, Trichoptera, and aquatic Diptera and terrestrial insects. Sympatric bull trout and brook trout had a high degree of dietary overlap. All fish exhibited size selective predation, and piscivory was rare. Similar habitat use, feeding behavior and diet of bull trout and brook trout, and aggressive interactions between these species suggest that, when habitat and prey resources are scarce, direct interference competition is likely, and the dominant behavior of brook trout may potentially displace bull trout.

Download or read book Brook Trout Removal as a Conservation Tool to Restore Eagle Lake Rainbow Trout written by Gerard Carmona Catot and published by . This book was released on 2009 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seasonal Habitat Use and Changes in Distribution of Juvenile Bull Trout and Cuttthrout Trout in Small High Gradient Streams written by Joseph L. Bonneau and published by . This book was released on 1994 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Review of Bull Trout Salvelinus Confluentus Life history and Habitat Use in Relation to Compensation and Improvement Opportunities written by McPhail, J. D. (John Donald) and published by Ministry of Environment, Lands and Parks. This book was released on 1996 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Brown Trout written by Javier Lobón-Cerviá and published by John Wiley & Sons. This book was released on 2017-12-18 with total page 821 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brown Trout: Biology, Ecology and Management A comprehensive guide to the most current research, history, genetics and ecology of the brown trout including challenging environmental problems The brown trout is an iconic species across its natural European distribution and has been introduced throughout the World. Brown Trout offers a comprehensive review of the scientific information and current research on this major fish species. While the brown trout is the most sought species by anglers, its introduction to various waters around the world is causing serious environmental problems. At the same time, introduction of exogenous brown trout lineages threats conservation of native gene pools of populations in many regions. The authors summarize the important aspects of the brown trout’s life history and ecology and focus on the impact caused by the species. The text explores potential management strategies in order to maintain numerous damaged populations within its natural distributional range and to ameliorate its impacts in exotic environments. The authors include information on a wide-range of topics such as recent updates in population genetics, evolutionary history, reproductive traits and early ontogeny, life history plasticity in anadromous brown trout and life history of the adfluvial brown trout and much more. This vital resource: Contains the latest research on the biology and ecology of brown trout Includes information on phylogeography, genetics, population dynamics and stock management Spotlights the brown trout’s introduction to regions around the world and the serious environmental impacts Offers a comprehensive review of conservation and management techniques Written for salmonid scientists and researchers, fishery and environmental managers, and students of population genetics, ecology and population dynamics, Brown Trout explores the most recent findings on the history, ecology and sustainability of this much-researched species.

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 Bull Trout Distribution and Abundance in the Waters on and Bordering the Warm Springs Indian Reservation 2000 Annual Report written by and published by . This book was released on 2000 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 stable 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 from the third year (2000) of the multi-year study aimed at determining the life history, genetics, habitat needs and limiting factors of bull trout in the lower Deschutes subbasin. Juvenile bull trout and brook trout (Salvelinus fontinalis) relative abundance was assessed in the Warm Springs River and Shitike Creek by night snorkeling. In the Warm Springs R. juvenile bull trout were slightly more numerous than brook trout, however, both were found in low densities. Relative densities of both species declined from 1999 observations. Juvenile bull trout vastly out numbered brook trout in Shitike Cr. Relative densities of juvenile bull trout increased while brook trout abundance was similar to 1999 observations in eight index reaches. The utility of using index reaches to monitor trends in juvenile bull trout and brook trout relative abundance was assessed in the Warm Springs R. for the second year. Mean relative densities of both species, within the index reaches was slightly higher than what was observed in a 2.4 km control reach. Mill Creek was surveyed for the presence of juvenile bull trout. The American Fisheries Society ''Interim protocol for determining bull trout presence'' methodology was field tested. No bull trout were found in the 2 km survey area.