Download or read book Factors Affecting Growth of Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri in Alpine Lakes of the Absaroka Beartooth Wilderness Montana written by Richard Kenneth Stiff and published by . This book was released on 1998 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Relative Contributions of Climate Variation Lake Trout Predation and Other Factors to the Decline of Yellowstone Lake Cutthroat Trout During the Three Recent Decades written by Lynn Robert Kaeding and published by . This book was released on 2010 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relative contributions of climate variation, lake trout Salvelinus namaycush predation, and other factors to the recent, three-decade decline of the lacustrine-adfluvial (i.e., a life-history form consisting of fish that mostly live in a lake but spawn in an inflowing tributary) Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri (YCT) population of Clear Creek, a Yellowstone Lake tributary, were evaluated. Strong growth of that population's storied spawning run between the early 1960s and 1978, when the run peaked at about 70,000 fish, had been considered key evidence of recovery of the lake's YCT population from formerly excessive angler harvest and other adverse factors. Thus the run's subsequent, almost continuous decline to about 500 fish in 2007 was perplexing. Gillnet catches of YCT at established lake locations likewise indicated a concurrent decline in the lake-wide YCT population. Prominent among the factors that may have importantly affected the YCT population during the recent decades was predation by the illegally introduced, reproducing, nonnative lake trout discovered in Yellowstone Lake in 1994. Data mainly taken from YCT in the spawning run (n = 29 years) and gillnet catch (n = 30 years) were examined for information useful to specifying the Leslie matrix of a dynamic, age-structured model that had climate as a covariate. The model, fitted to spawning run size and mean total length (TL) of YCT in the run during 1977-2007 (n = 29 data years), explained 87% of variation in observed run size, 86% of variation in observed mean TL, and strongly suggested that climate (as indexed by total-annual air degree-days> 0°C measured on the lake's north shore) had an important effect on recruitment of age-0 YCT to subsequent spawning runs. Results also suggested that an effect of lake trout predation on survival of age-1 to age-5 YCT became apparent only during the recent decade. The important test of ongoing efforts to control lake trout in Yellowstone Lake and thereby limit their predation on YCT - on the basis of data for YCT - will occur when climatic conditions improve for YCT recruitment to the Clear Creek and other YCT spawning stocks of the lake.

Download or read book Fluctuations in Age Composition and Growth Rate of Cutthroat Trout in Yellowstone Lake written by Ross V. Bulkley and published by . This book was released on 1961 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Age composition, growth rate, and year-class strength of Yellowstone Lake cutthroat trout from collections made in 1948 and from 1950 to 1959 are analyzed to relate total catch changes in age composition and growth rate. An increase in growth rate of fish fully recruited to the fishery and a decrease in percentages of fish belonging to age groups VI and VII are attributed to an increase in fishing pressure. Mean age of the catch varied with year-length of the catch has remained high, suggesting that production is more efficient now than in past years. Maximum equilibrium yield may be near. If the catch continues to increase at the present rate, it may become excessive within the next few years.

Download or read book Genetic Considerations for the Conservation and Management of Yellowstone Cutthroat Trout Oncorhynchus Clarkii Bouvieri in Yellowstone National Park written by David Joel Janetski and published by . This book was released on 2006 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: A key component to conservation is an accurate understanding of genetic subdivision within a species. Despite their ecological and economic importance, relatively little is understood about the genetic structuring of Yellowstone cutthroat trout in Yellowstone National Park. Here, we use traditional (Fst, Rst, Nm, and AMOVA) and modern (Bayesian assignment tests, coalescent theory, and nested clade analysis) analytical approaches to describe the population genetic subdivision of cutthroat trout spawning populations in Yellowstone Lake and to identify genetically distinct population segments throughout Yellowstone National Park. Evidence for restricted gene flow between spawning populations within Yellowstone Lake was detected using nested clade analysis. This is the first molecular evidence for restricted gene flow between spawning populations in Yellowstone Lake. In contrast, traditional methods such as Fst and Rst as well as the Bayesian clustering program STRUCTURE v2.0 failed to detect evidence for restricted gene flow. Across our sampling range within Yellowstone National Park, eleven genetically distinct cutthroat trout population segments were detected. These showed a general pattern of small, isolated populations with low genetic diversity in headwater streams and wide-spread, genetically diverse populations in higher-order rivers. We recommend populations be managed to maintain current levels of genetic diversity and gene flow. Based on the recent decline of and distinct morphological, behavioral, and genetic nature of cutthroat trout in Yellowstone Lake, we recommend the Yellowstone Lake spawning populations collectively be recognized as an evolutionarily significant unit.

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.

Download or read book Fluctuations in Age Composition and Growth Rate of Cutthroat Trout in Yellowstone Lake Classic Reprint written by United States Fish and Wildlife Service and published by Forgotten Books. This book was released on 2017-11-19 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Fluctuations in Age Composition and Growth Rate of Cutthroat Trout in Yellowstone Lake Oliver B. Cope. 1961. 62 pp. 56. Limnology of Yellowstone Lake in Relation to the Cutthroat Trout, by Norman G. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Download or read book Estimates of Predator Consumption of Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri in Yellowstone Lake written by Paul Rodney Stapp and published by . This book was released on 2002 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Dynamics of Yellowstone Cutthroat Trout and Lake Trout in the Yellowstone Lake Ecosystem written by John Michael Syslo and published by . This book was released on 2015 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of lake trout Salvelinus namaycush into Yellowstone Lake preceded the collapse of the native Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri population. As a system with a simple fish assemblage and several long-term data sets, Yellowstone Lake provided a unique opportunity to evaluate the ecology of a native salmonid in the presence of a non-native salmonid population undergoing suppression in a large natural lake. Diet data for Yellowstone cutthroat trout and lake trout were evaluated at varying densities to determine the effects of density on diet composition. Temporal diet shifts from 1996-1999 to 2011-2013 were likely caused by limitation of prey fish for lake trout. Diets, stable isotopes, and depth-related patterns in CPUE indicated lake trout> 300 mm consumed primarily amphipods, making them trophically similar to Yellowstone cutthroat trout from during 2011-2013. A lake trout removal program was initiated during 1995 to reduce predation on Yellowstone cutthroat trout. Abundance and fishing mortality were estimated for lake trout from 1998 through 2013 and Yellowstone cutthroat trout from 1986 through 2013. Density-dependence was evaluated by examining individual growth, weight, maturity, and pre-recruit survival as a function of abundance. In addition, a simulation model was developed for the lake trout- Yellowstone cutthroat trout system to determine the probability of Yellowstone cutthroat trout abundance persisting at performance metrics given potential reductions in lake trout abundance. Estimates of Yellowstone cutthroat trout abundance varied 5-fold and lake trout abundance varied 6-fold. Yellowstone cutthroat trout weight and pre-recruit survival decreased with increasing Yellowstone cutthroat trout abundance; however, individual growth and maturity were not related to abundance. Lake trout population metrics did not vary with lake trout abundance. Simulation model results were variable because of uncertainty in lake trout pre-recruit survival. Conservative estimates for required lake trout reductions were> 97% of 2013 abundance for a> 70% probability of Yellowstone cutthroat trout persistence at the performance metrics outlined in the Native Fish Conservation Plan. Lake trout removal will likely reduce lake trout abundance and result in Yellowstone cutthroat trout recovery if the amount of fishing effort exerted in 2013 is maintained for at least 15 years.

Download or read book Migrate Mutate Or Die written by Sarah Gandhi-Besbes and published by . This book was released on 2016 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yellowstone National Park is a relatively pristine ecosystem preserved through time. The Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri population, inhabiting shallower waters in Yellowstone Lake and spawning in its tributaries, has been declining primarily due to the introduction of a predatory fish. The lake trout Salvelinus namaycush, which rapidly grow to large sizes, feed on the Yellowstone cutthroat trout, breed and spawn in Yellowstone Lake, and dwell in deeper waters out of predatory reach. The Yellowstone cutthroat trout is relied upon both directly and indirectly by more than 40 species within Yellowstone National Park. The grizzly bear Ursus arctos horribilis, bald eagle Haliaeetus leucocephalus, and osprey Pandion halaetus all feed directly on the spawning fish. This study looks at how the declining Yellowstone cutthroat trout populations affect these predatory populations, and what their populations may look like should current trends continue into the year 2030. Conducting a meta-analysis and collecting primary data allowed for statistical projections predicting and comparing estimated future populations. The ecological change in Yellowstone Lake provides insight into how the concerns of one ecosystem affects multiple.

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.

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.

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.

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.

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.

Download or read book Informative Correlations Among Metrics of Yellowstone Lake Cutthroat Trout Caught by Two Quantitative Methods Across Three Recent Decades written by Lynn Robert Kaeding and published by . This book was released on 2013 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri (YCT) of Yellowstone Lake, in Yellowstone National Park, Wyoming, is an iteroparous fish and obligate stream spawner. The size and several other attributes of the annual YCT spawning run in one lake tributary, Clear Creek, have been periodically estimated for several decades. The trends in that run's metrics have been assumed to depict the trends in the lake's YCT population as a whole, although such associations had not been substantiated by statistical analyses. The present study revealed strong correlations between metrics of YCT in the run (years 1977-2007) and of "prespawner" YCT (i.e., mature fish whose excised gonads indicated that the fish would have spawned the next year) caught in gill nets set in various lake locations the preceding fall. Data for both capture methods also revealed a negative effect of spawning population density on YCT somatic growth, which is known to be positively associated with fecundity. This study showed that most metrics of YCT in the Clear Creek spawning run were indicative of those of prespawner YCT in Yellowstone Lake and aided the development of population models that are needed to determine the causal factors in the recent, three-decade population decline of YCT.

Download or read book A Case Study in Natural Resource Policy Yellowstone Cutthroat Trout Oncorhynchus Clarki Bouvieri in the Greater Yellowstone Ecosystem written by Brad Johnson and published by . This book was released on 2007 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Greater Yellowstone Ecosystem is hailed as one of the most intact temperate ecosystems in the world. Within the ecosystem the Yellowstone cutthroat trout has been noted as both a keystone species and an indicator of ecosystem health. As anthropogenic induced stress and its effects on natural systems have become more readily apparent, a call has risen for a new holistic form of natural resource policy development and implementation. The Ecosystem Approach, based on the principles of sustainability, is a multidisciplinary, cross-sectoral policy paradigm, which serves that function for this study.