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Book Distribution  Movements  and Life history Characteristics of Yellowstone Cutthroat Trout Oncorhynchus Clarkii Bouvieri in the Upper Yellowstone River Drainage

Download or read book Distribution Movements and Life history Characteristics of Yellowstone Cutthroat Trout Oncorhynchus Clarkii Bouvieri in the Upper Yellowstone River Drainage written by Brian Daniel Ertel and published by . This book was released on 2011 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distribution and abundance of Yellowstone cutthroat trout, Oncorhynchus clarkii bouvieri, has declined across the historic range because of anthropogenic influences. Habitat has been fragmented and non-native species have been introduced that compete with, feed upon, or interbreed with cutthroat trout. As a result, many cutthroat trout populations are now isolated in headwater streams and life-history forms are lost or reduced. The upper Yellowstone River basin, above Yellowstone Lake, offers a rare opportunity to study Yellowstone cutthroat trout in a large, intact, river system with few anthropogenic influences. Understanding of life-history forms present in the upper Yellowstone River basin assist in proper conservation and management of the watershed. To determine cutthroat trout life-history forms present, their abundance, and habitat preferences, a combination of radio-telemetry, electrofishing, underwater census, habitat assessment, and age and growth were used. Movements of 151 cutthroat trout were tracked by aircraft, 2003-2005. Most relocated fish (98%) followed a lacustrine-adfluvial life history migration pattern, spending an average 24 days in the river. Cutthroat began entering the river in April and most emigrated by August. Fish migrated as far as 67 km to spawn and spawning aggregations within the system were found in only 11 locations. Underwater census and electrofishing surveys were used to determine fish distribution and abundance in the Yellowstone River and its tributaries. Main stem cutthroat trout densities were low and not evenly distributed. A mean of 8 fish/500 m reach were sampled with the majority in 8 reaches. Juvenile (150 mm, 2 years old) and large adult (330 mm,4 years old) cutthroat trout were found in the main stem, but fish from 151-330 mm (age 3) were absent. Within tributaries, fish densities ranged from 1.7-49.5 fish/100 m reach. Fish up to 305 mm were sampled and ranged 1 to 4 years in age. Data from this study suggest most cutthroat trout in the upper Yellowstone River express a lacustrine-adfluvial life history, however, some fluvial fish are present in tributaries. These findings will be important in driving conservation and management decisions in this drainage and provide critical information in future ESA listing considerations.

Book Atlas of Yellowstone

    Book Details:
  • Author : W. Andrew Marcus
  • Publisher : Univ of California Press
  • Release : 2022-01-11
  • ISBN : 0520976924
  • Pages : 366 pages

Download or read book Atlas of Yellowstone written by W. Andrew Marcus and published by Univ of California Press. This book was released on 2022-01-11 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of the award-winning Atlas of Yellowstone contains 50% new material, making it the authoritative reference for the world’s first national park on its 150th anniversary. The publication of the Atlas of Yellowstone, Second Edition coincides with the 150th anniversary of the founding of Yellowstone National Park—a major international event. The atlas is an accessible, comprehensive guide that presents Yellowstone’s story through compelling visualizations rendered by award-winning cartographers at the University of Oregon. Readers of this new edition of the Atlas of Yellowstone will explore the contributions of Yellowstone to preserving and understanding natural and cultural landscapes, to informing worldwide conservation practices, and to inspiring national parks around the world, while also learning about the many struggles the park faces in carrying out its mission. Ranging from Indigenous Americans and local economies to geysers and wildlife migrations, from the life of one wolf to the threat of wildfires, each page provides leading experts’ insights into the complexity and significance of Yellowstone. Key elements of the atlas include: More than 1,000 maps, graphics, and photographs Contributions from more than 130 experts Detailed topographic maps of Yellowstone and Grand Teton National Parks Exploration of Yellowstone National Park’s influence over 150 years on conservation practice, park management, and American culture New, detailed visualizations of wildlife that take advantage of modern GPS technology to track individual animals and entire herds Place-name origins for Yellowstone and Grand Teton National Parks and the surrounding region

Book Life History Migrations of Adult Yellowstone Cutthroat Trout in the Upper Yellowstone River

Download or read book Life History Migrations of Adult Yellowstone Cutthroat Trout in the Upper Yellowstone River written by Brian D. Ertel and published by . This book was released on 2017 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of salmonid life history types at the watershed scaleis increasingly recognized as a cornerstone for effective management. In this study, we used radiotelemetry to characterize the life history movements of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in the upper Yellowstone River, an extensive tributary that composes nearly half of the drainage area of Yellowstone Lake. In Yellowstone Lake, Yellowstone Cutthroat Trout have precipitously declined over the past 2 decades primarily due to predation from introduced Lake Trout Salvelinus namaycush. Radio tags were implanted in 152 Yellowstone Cutthroat Trout, and their movements monitored over 3 years. Ninety-six percent of taggedtrout exhibited a lacustrine?adfluvial life history, migrating upstream a mean distance of 42.6 km to spawn, spending an average of 24 d in the Yellowstone River before returning to Yellowstone Lake. Once in the lake, complex postspawning movements were observed. Only 4% of radio-tagged trout exhibited a fluvial or fluvial?adfluvial life history. Low prevalence of fluvial and fluvial?adfluvial life histories was unexpected given the large size of the upper river drainage. Study results improve understanding of life history diversity in potamodromous salmonids inhabiting relatively undisturbed watersheds and provide a baseline for monitoring Yellowstone Cutthroat Trout response to management actions in Yellowstone Lake.

Book Biology  Status  and Management of Yellowstone Cutthroat Trout

Download or read book Biology Status and Management of Yellowstone Cutthroat Trout written by Robert E. Gresswell and published by . This book was released on 2011 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri were historically distributed in the Yellowstone River drainage (Montana and Wyoming) and the Snake River drainage (Wyoming, Idaho, Utah, Nevada, and probably Washington). Individual populations evolved distinct life history characteristics in response to the diverse environments in which they were isolated after the last glaciation. Anthropogenic activities have resulted in a substantial decline (42% of the historical range is currently occupied; 28% is occupied by core [genetically unaltered] populations), but the number of extant populations, especially in headwater streams, has precluded listing of this taxon under the Endangered Species Act. Primary threats to persistence of Yellowstone cutthroat trout include (1) invasive species, resulting in hybridization, predation, disease, and interspecific competition; (2) habitat degradation from human activities such as agricultural practices, water diversions, grazing, dam construction, mineral extraction, grazing, timber harvest, and road construction; and (3) climate change, including an escalating risk of drought, wildfire, winter flooding, and rising temperatures. Extirpation of individual populations or assemblages has led to increasing isolation and fragmentation of remaining groups, which in turn raises susceptibility to the demographic influences of disturbance (both human and stochastic) and genetic factors. Primary conservation strategies include (1) preventing risks associated with invasive species by isolating populations of Yellowstone cutthroat trout and (2) connecting occupied habitats (where possible) to preserve metapopulation function and the expression of multiple life histories. Because persistence of isolated populations may be greater in the short term, current management is focused on isolating individual populations and restoring habitats; however, this approach implies that humans will act as dispersal agents if a population is extirpated because of stochastic events.

Book Influence of Basin scale Physical Variables on Life History Characteristics of Cutthroat Trout in Yellowstone Lake

Download or read book Influence of Basin scale Physical Variables on Life History Characteristics of Cutthroat Trout in Yellowstone Lake written by Robert E. Gresswell and published by . This book was released on 1997 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Individual spawning populations of Yellowstone cutthroat trout Oncorhynchus clarki bouvieri differ in life history characteristics associated with broad spatial and temporal environmental patterns, but relationships between specific life history characteristics of Yellowstone cutthroat trout and physical apsects of the environment are poorly understood. We examined basin-scale physical characteristics of tributary drainages and subbasins of Yellowstone Lake in relation to timing (peak and duration) of lacustrine-adfluvial Yellowstone cutthroat trout spawning migrations and mean length of cutthroat trout spawners in 27 tributaries to the lake. Stream drainages varied along gradients that can be described by mean aspect, mean elevation, and drainage and stream size. Approximately two-thirds of the variation in the timing of the peak of the annual cutthroat trout spawning migrations and average length of spawners was explained by third-order polynomial regressions with mean aspect and basin area as predictor variables. Because most cutthroat trout ascend tributaries soon after peak runoff, it appears that the influence of basin-scale physical variables on the date of the migration peak is manifested by the pattern of stream discharge. Spawner length does not seem to be a direct function of stream size in the Yellowstone Lake watershed, and aspect of the tributary basin seems to have a greater influence on the body length of cutthroat trout spawners than does stream size. Mechanisms that explain how the interaction of basin-scale physical variables influence spawner length were not investigated directly; however, we found evidence of distinct aggregations of cutthroat trout that are related to physical and limnological characteristics of the lake subbasins, and there is some indication that lake residence may be related to tributary location.

Book Life History Characteristics and the Effects of Climate on Growth of Yellowstone Cutthroat Trout in Headwater Basins

Download or read book Life History Characteristics and the Effects of Climate on Growth of Yellowstone Cutthroat Trout in Headwater Basins written by Patrick Ryan Uthe and published by . This book was released on 2015 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone Cutthroat Trout was historically distributed throughout the Upper Yellowstone and Upper Snake River drainages, but now occupies only 42% of its original range because of habitat degradation and introduced salmonid species. Many of the current strongholds are located on public land in mountainous watersheds with low human disturbance. However, knowledge of life history characteristics of headwater populations is limited. Moreover, streams throughout the Rocky Mountains have already exhibited symptoms of climate change through alterations in thermal and hydrologic regimes, but it is unknown how these changes will affect fish populations. To address these needs, we implemented a mark-recapture study on five populations of trout from Spread Creek, Wyoming, and Shields River, Montana, to estimate annual growth, survival rates, and movement patterns, and document the effects of discharge, temperature, and food availability on summer growth patterns. Survival rates were high compared to survival rates of other Cutthroat Trout subspecies and large trout generally had lower survival rates than small trout. Downstream movements out of streams by tagged trout were substantial. Annual growth rates varied among streams and size classes, but were relatively low compared to populations of Yellowstone Cutthroat Trout from large, low elevation streams. Trout grew more in length than weight in summer, suggesting an investment in structural growth rather than accumulation of reserve tissues. Temperature and discharge had strong effects on summer growth, but the effect of discharge was greater for growth in weight than in length, probably resulting from increased prey availability at high discharges. Temperature interacted with fish length such that small trout responded favorably to increased average daily temperatures near physiological optima and increased growing season length, whereas large trout responded negatively to warming temperatures. These estimates of key demographic parameters are useful in developing management and conservation strategies. Additionally, we documented that even under thermally suitable conditions, discharge can have significant effects on growth, making it important to consider multiple factors affected by climate change when devising climate adaptation strategies for coldwater fishes.

Book Yellowstone Cutthroat Trout  Oncorhynchus Clarki Bouvieri

Download or read book Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri written by Robert E. Gresswell and published by . This book was released on 2009 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This assessment examines the biology, ecology, conservation status, and management of the Yellowstone cutthroat with specific reference to the geographic and ecological characteristics of USFS Region 2. Although much of the literature on the subspecies originates from field investigations outside Region 2, this document places that literature in the ecological and social context of the central Rocky Mountains. Similarly, this assessment focuses on the reproductive behavior, population dynamics, and life-history characteristics of the Yellowstone cutthroat trout under the current environment conditions." --page 8

Book Life history Organization of Cutthroat Trout in Yellowstone Lake and Its Management Implications

Download or read book Life history Organization of Cutthroat Trout in Yellowstone Lake and Its Management Implications written by Robert E. Gresswell and published by . This book was released on 1994 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life-history organization of the cutthroat trout (Oncorhvnchus clarki) may be viewed at various levels, including species, subspecies, metapopulation, population, or individual. Each level varies in spatial scale and temporal persistence, and components at each level continually change with changes in environment. Cutthroat trout are widely distributed throughout the western USA, and during its evolution the species has organized into fourteen subspecies with many different life-history characteristics and habitat requirements. Within subspecies, organization is equally complex. For example, life-history traits, such as average size and age, migration strategy, and migration timing, vary among individual spawning populations of Yellowstone cutthroat trout (Oncorhvnchus clarki bouvieri) in tributary streams of Yellowstone Lake. In this study specific life-history traits of adfluvial cutthroat trout spawners from Yellowstone Lake were examined in relation to habitat of tributary drainages and subbasins of the lake. Results suggest that stream drainages vary along gradients that can be described by mean aspect, mean elevation, and drainage size. Approximately two-thirds of the variation in the timing of annual cutthroat trout spawning migrations and average size of spawners can be described by third-degree polynomial regressions with mean aspect and elevation as predictor variables. Differences in average size and growth of cutthroat trout suggested metapopulation substructure related spatial heterogeneity of environmental characteristics of individual lake subbasins. Evidence that polytypic species can adapt to heterogenous environments, even within a single lake, has implications for the conservation, restoration, and management of many freshwater fishes. Understanding the consequences of human perturbations on life-history organization is critical for management of the cutthroat trout and other polytypic salmonid species. Loss of diversity at the any hierarchical level jeopardizes long-term ability of the species to adapt to changing environments, and it may also lead to increased fluctuations in abundance and yield and increase risk of extinction. Recent emphasis on a holistic view of natural systems and their management is associated with a growing appreciation of the role of human values in these systems. The recreational fishery for Yellowstone cutthroat trout in Yellowstone National Park is an example of the effects of management on a natural-cultural system. Although angler harvest has been drastically reduced or prohibited, the recreational value of Yellowstone cutthroat trout estimated by angling factors (e.g., landing rate or size) ranks above all other sport species in Yellowstone National Park. To maintain an indigenous fishery resource of this quality with hatchery propagation is not economically or technically feasible. Nonconsumptive uses of the Yellowstone cutthroat trout including fish-watching and intangible values, such as existence demand, provide additional support for protection of wild Yellowstone cutthroat trout populations. A management strategy that reduces resource extraction has provided a means to sustain a quality recreational fishery while enhancing values associated with the protection of natural systems.

Book Life history Organization of Yellowstone Cutthroat Trout  Oncorhynchus Clarki Bouvieri  in Yellowstone Lake 1994  Gresswell  Robert E   Liss  W  J   Larson  Gary L

Download or read book Life history Organization of Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri in Yellowstone Lake 1994 Gresswell Robert E Liss W J Larson Gary L written by Robert E. Gresswell and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life-history organization of the cutthroat trout (Oncorhynchus clarki) may be viewed at various levels, including species, subspecies, metapopulation, population, or individual. Each level varies in spatial scale and temporal persistence, and components at each level continually change with changes in environment. Cutthroat trout are widely distributed throughout the western United States, occurring in such diverse environments as coastal rivers of the Pacific Northwest and interior streams of the Great Basin. During its evolution the species has organized into 14 subspecies with many different life-history characteristics and habitat requirements. Within subspecies, organization is equally complex. For example, life-history traits, such as average size and age, migration strategy, and migration timing, vary among individual spawning populations of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) in tributary streams of Yellowstone Lake. Understanding the effects of human perturbations on life-history organization is critical for management of the cutthroat trout and other polytypic salmonid species. Loss of diversity at any hierarchical level jeopardizes the long-term ability of the species to adapt to changing environments, and it may also lead to increased fluctuations in abundance and yield and increase the risk of extinction.

Book Range Wide Status of Yellowstone Cutthroat Trout  Oncorhynchus Clarki Bouvieri   2001  2003

Download or read book Range Wide Status of Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri 2001 2003 written by Bruce E. May and published by Palala Press. This book was released on 2018-03-03 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Book Range Wide Status of Yellowstone Cutthroat Trout  Oncorhynchus Clarki Bouvieri

Download or read book Range Wide Status of Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri written by Bruce E May and published by Palala Press. This book was released on 2015-09-05 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Book Yellowstone Cutthroat Trout

Download or read book Yellowstone Cutthroat Trout written by Michael K. Young and published by . This book was released on 2017 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) is a member of the Salmonidae, the family of trout, salmon, grayling, and whitefish. This subspecies was first described by C. E. Bendire in 1882 based on a sample from a disjunct population in Waha Lake, Idaho (Behnke 1992), but many explorers had made earlier observations of this subspecies in Montana and Wyoming (May 1996). Native Americans undoubtedly recognized this species for much longer. The Yellowstone cutthroat trout is visually distinguished from other trout species by its two prominent red slashes on the lower jaw, and from other cutthroat trout subspecies by its medium-large, black spots that tend to be concentrated posteriorly and its drab brownish, yellowish, or silvery coloration, with brighter colors generally absent even in mature fish (Behnke 1992; Baxter and Stone 1995). The relation of Yellowstone cutthroat trout to Snake River fine-spotted cutthroat trout O. c. spp. is problematic. Early genetic analyses could not distinguish these subspecies (Loudenslager and Kitchin 1979; Leary et al. 1987), but recent attempts have been more successful (Kruse 1995). Behnke (1992) contended that the Snake River fine-spotted cutthroat trout constituted a separate subspecies as a consequence of its distinctive appearance, unsurprisingly, caused by an abundance of ground-pepper-sized spots and its novel life history involving extensive movement among spring streams, small tributaries, and large rivers in a geologically young basin (Kiefling 1978). Regardless, it has never been formally recognized and is often considered synonymous with Yellowstone cutthroat trout (e.g., for purposes of federal listing; Dufek et al. 1999).

Book Yellowstone Cutthroat Trout Distribution and Habitat Conditions of the Yellowstone River Drainage  Bridger Teton National Forest

Download or read book Yellowstone Cutthroat Trout Distribution and Habitat Conditions of the Yellowstone River Drainage Bridger Teton National Forest written by Jason C. Burckhardt and published by . This book was released on 2009 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Ecology of Atlantic Salmon and Brown Trout

Download or read book Ecology of Atlantic Salmon and Brown Trout written by Bror Jonsson and published by Springer Science & Business Media. This book was released on 2011-05-03 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.

Book Ecological and Environmental Investigations of Competition Between Native Yellowstone Cutthroat Trout  Oncorhynchus Clarkii Bouvieri   Rainbow Trout  Oncorhynchus Mykiss   and Their Hybrids

Download or read book Ecological and Environmental Investigations of Competition Between Native Yellowstone Cutthroat Trout Oncorhynchus Clarkii Bouvieri Rainbow Trout Oncorhynchus Mykiss and Their Hybrids written by Steven Michael Seiler and published by . This book was released on 2007 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduced species can have dramatic impacts within the native communities where they become established. In western North America, native cutthroat trout (Oncorhynchus clarkii) are experiencing drastic declines due to habitat alteration and fish introductions. Rainbow trout ( O. mykiss) are thought to be especially detrimental to cutthroat trout because they share similar life histories and can form fertile hybrid offspring, compounding interspecific competition through added pressure from hybrids. My dissertation consists of five studies developed to test ecological and environmental factors that may influence the spread of rainbow trout and cutthroat-rainbow hybrid trout within native Yellowstone cutthroat trout ( O. c. bouvieri) populations. I raised Yellowstone cutthroat trout, rainbow trout, and reciprocal first generation hybrids under common conditions and tested for differences in morphology and swimming stamina (Chapter 1), aggression and foraging ability (Chapter 2), and the strength of interspecific competition on the growth rate of Yellowstone cutthroat trout (Chapter 3). I also surveyed trout and environmental characteristics from the South Fork of the Snake River watershed to test for morphological differences between wild Yellowstone cutthroat trout, rainbow trout, and hybrids (Chapter 4) and to examine the influence of environmental characteristics on the extent of hybridization (Chapter 5). I found differences in morphology, swimming stamina, foraging behavior, and growth between Yellowstone cutthroat trout, rainbow trout, and their hybrids that place cutthroat trout at a disadvantage. The field survey found body shape differences between Yellowstone cutthroat trout, rainbow trout, and hybrids consistent with those of trout raised in the laboratory with high predictability of genetic class based on morphology alone. The degree of hybridization present at field sampling locations was related to the size of the stream and summer water temperature of the sampling location; however, level of hybridization could also be the result of distance from a location where most rainbow trout were stocked. My work provides some of the first tests of competition between cutthroat trout and rainbow trout and the influence of hybridization. This dissertation will aid in cutthroat trout conservation efforts and be of general interest to invasive species ecologists in better understanding the dynamics of invasive species success.

Book A Long Term Comparison of Yellowstone Cutthroat Trout Abundance and Size Structure in Their Historical Range in Idaho

Download or read book A Long Term Comparison of Yellowstone Cutthroat Trout Abundance and Size Structure in Their Historical Range in Idaho written by and published by . This book was released on 2002 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: We compared estimates of population abundance and size structure for Yellowstone cutthroat trout Oncorhynchus clarki bouvieri obtained by electrofishing 77 stream segments across southeastern Idaho in the 1980s and again in 1999-2000 to test whether populations of Yellowstone cutthroat trout had changed. Sites sampled in the 1980s were relocated in 1999-2000 by using maps and photographs or by finding original site-boundary stakes, so that the same reach of stream was sampled during both periods. Abundance of Yellowstone cutthroat trout longer than 10 cm did not change, averaging 41 fish/100 m of stream during both the 1980s and 1999-2000. The proportion of the total catch of trout composed of Yellowstone cutthroat trout also did not change, averaging 82% in the 1980s and 78% in 1999-2000. At the 48 sites where size structure could be estimated for both periods, the proportion of Yellowstone cutthroat trout that were 10-20 cm long declined slightly (74% versus 66%), but the change was due entirely to the shift in size structure at the Teton River sites. The number of sites that contained rainbow trout O. mykiss or cutthroat trout 3 rainbow trout hybrids rose from 23 to 37, but the average proportion of the catch composed of rainbow trout and hybrids did not increase (7% in both the 1980s and 1999-2000). Although the distribution and abundance of Yellowstone cutthroat trout have been substantially reduced in Idaho over the last century, our results indicate that Yellowstone cutthroat trout abundance and size structure in Idaho have remained relatively stable at a large number of locations for the last 10-20 years. The expanding distribution of rainbow trout and hybrids in portions of the upper Snake River basin, however, calls for additional monitoring and active management actions.

Book Status and Management of Interior Stocks of Cutthroat Trout

Download or read book Status and Management of Interior Stocks of Cutthroat Trout written by Robert E. Gresswell and published by . This book was released on 1988 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: