Download or read book Ecosystem Consequences of Declining Yellowstone Cutthroat Trout in Yellowstone Lake and Spawning Streams written by Lusha M. Tronstad and published by . This book was released on 2008 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduced Lake Trout Alter Nitrogen Cycling Beyond Yellowstone Lake written by Lusha Marguerite Tronstad and published by . This book was released on 2015 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduced predators can have large effects on the ecosystem in which they were introduced, but how much these effects extend to other ecosystems beyond the invaded one is less known. We compared how lake trout (Salvelinus namaycush) affected nutrient cycling in an invaded and adjacent ecosystem in Yellowstone National Park, Wyoming, USA. Introduced lake trout in Yellowstone Lake caused the native Yellowstone cutthroat trout (Oncoryhynchus clarkii bouvieri) population to decline. Native cutthroat trout are a dominant animal in the lake and may alter nutrient cycling in both Yellowstone Lake where they reside and in tributary streams used for spawning. We estimated changes in nutrient transport and nutrient uptake in both Yellowstone Lake and Clear Creek, a spawning stream, before and after the invasion of lake trout. Annual area-specific excretion fluxes from cutthroat trout were nine times higher in Clear Creek compared to Yellowstone Lake when cutthroat trout were abundant. However, fluxes within the lake and stream were similar after cutthroat trout declined. In Yellowstone Lake, zooplankton excretion supplied 86% of ammonium (NH4+) that was taken up, but cutthroat trout only supplied 0.3% after the introduction of lake trout. Conversely, NH4+ excreted by cutthroat trout was likely a major flux in Clear Creek, because NH4+ fluxes from cutthroat trout exceeded watershed export of NH4+ in years when 3000 cutthroat trout spawned. Furthermore, NH4+ excretion fluxes from spawning cutthroat trout in Clear Creek supplied up to 6.1% of the NH4+ demanded by microbes after the introduction of lake trout. However, based on modeled past NH4+ uptake, we estimated that up to 60% of NH4+ excreted by spawning cutthroat trout may have been taken up by stream microbes when cutthroat trout were abundant. Therefore, transported NH4+ from spawning cutthroat trout was likely an integral part of N cycling in tributary streams in the past. By comparing the effects of declining cutthroat trout on two ecosystems, we show that lake trout had a larger effect on N cycling within an adjacent stream ecosystem than the invaded lake ecosystem itself, because the migratory behavior of cutthroat trout concentrated them in spawning streams increasing their effect.
Download or read book Yellowstone Fishes written by John D. Varley and published by Stackpole Books. This book was released on 1998 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: This richly illustrated and thoroughly researched reference covers all the species of fish and every aspect of their existence in one of the most famous sport fisheries in the world. This edition includes new material on the impact of forest fires and the introduction of non-native species; an expanded chapter on angling; and an assessment of recent management policies. Full color plates and historic b&w photos.
Download or read book Indirect Effects of Bioinvasions in Yellowstone Lake The Response of River Otters to Declines in Native Cutthroat Trout written by Jamie R. Crait and published by . This book was released on 2015 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonnative species threaten ecosystems throughout the world ? including protected reserves. In Yellowstone National Park, river otters Lontra canadensis depend on native cutthroat trout as prey. However, nonnative lake trout and whirling disease have significantly reduced the abundance of these native fish in the park's largest body of water, Yellowstone Lake. We studied the demographic and behavioral responses of otters to declining cutthroat trout on Yellowstone Lake and its tributaries. From 2002-2008, we monitored otter activity at latrine (scent-marking) sites, collected scat for prey identification, and used individual genotypes from scat and hair samples to evaluate survival and abundance with capture?recapture methods. Otter activity at latrines decreased with declines in cutthroat trout, and the prevalence of these fish in otter scat declined from 73% to 53%. Cutthroat trout numbers were the best predictor of temporal variation in apparent survival, and mean annual survival for otters was low (0.72). The density of otters in our study area (1 otter per 13.4 km of shoreline) was also low, and evidence of a recent genetic bottleneck suggests that otter abundance might have declined prior to our study. River otters in and around Yellowstone Lake appear to be responding to reductions in cutthroat trout via changes in distribution, diet, and possibly survival and abundance. Our results provide a baseline estimate for monitoring the broader outcome of management efforts to conserve native cutthroat trout and emphasize the indirect ecosystem consequences of invasive species.
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 Mortality Studies on Cutthroat Trout in Yellowstone Lake by Orville P Ball and Oliver B Cope written by Orville P. Ball and published by . This book was released on 1961 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a study of the Yellowstone Lake cutthroat trout, Salmo clarki lewisi, by the U.S. Fish and Wildlife Service, effects of environment on mortality of eggs, immature fish, spawners, and postspawners were measured for various components of the population in Yellowstone Lake (Wyoming). Five methods for estimating mortality of adults on spawning runs are described, with counting and tagging as the principal procedures. Of the total number of eggs deposited in the gravel, 60 to 75 percent died before hatching, and 99.6 percent had died by the time the fingerlings enetered Yellowstone Lake. In Arnica Creek runs, 48.6 percent died in the stream, 40.2 died later in the lake of natural causes, 7.6 were taken by fishermen, and 3.6 percent were alive 2 years later. The white pelican is a serious predator on cutthroat trout in Yellowstone Lake. From 1949 to 1953 fishermen caught 11.6 percent of the catchable trout available to them. Migrations of adult fish in Yellowstone Lake were traced through tagging.
Download or read book Changing Numbers of Spawning Cutthroat Trout in Tributary Streams of Yellowstone Lake and Estimates of Grizzly Bears Visitings Streams from DNA written by Mark A. Haroldson and published by . This book was released on 2005 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985-87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and have the potential to reduce the native cutthroat population and negatively impact terrestrial predators that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n = 25) from areas of Yellowstone Lake surveyed during the previous study to determine if changes in spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested a considerable decline between study periods in streams in the West Thumb area of the lake. The apparent decline may be due to predation by lake trout. Indices of bear use also declined on West Thumb area streams. We used DNA from hair collected near spawning streams to estimate the minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in 1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample, but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were only documented in 1 segment of the lake, whereas 12 (16%) were found in 2-3 lake segments. Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on 6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories derived from DNA and the Jolly-Seber procedure in Program MARK to produce annual estimates of grizzly bears visiting streams. Approximately 68 grizzly bears visited the vicinity of cutthroat trout spawning streams annually. Thus, approximately 14-21% of grizzly bears in the Greater Yellowstone Ecosystem (GYE) may have used this threatened food resource annually. Yellowstone National Park (YNP) is attempting to control the lake trout population in Yellowstone Lake; our results underscore the importance of that effort to grizzly bears.
Download or read book Equilibrium Yield and Management of Cutthroat Trout in Yellowstone Lake written by Norman Gustaf Benson and published by . This book was released on 1963 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equilibrium yield of the cutthroat trout, Salmo clarki lewisi Girard, in Yellowstone Lake, Wyo., is determined from data on catch and spawning runs from 1945 to 1961. Changes in growth rate, spawning runs, mortality rates, and year-class strength are related to differences in total catch. Three stages of exploitation of the stock are defined and the maximum safe catch or equilibrium yield is estimated at 325,000 trout. Management of the sport fishery according to equilibrium yield is discussed with reference to regulations, distribution of fishing pressure, planting, and interspecific competition. The Yellowstone River fishery is treated briefly.
Download or read book Climate Change in Wildlands written by Andrew J Hansen and published by Island Press. This book was released on 2016-06-07 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists have been warning for years that human activity is heating up the planet and climate change is under way. We are only just beginning to acknowledge the serious effects this will have on all life on Earth. The federal government is crafting broad-scale strategies to protect wildland ecosystems from the worst effects of climate change. One of the greatest challenges is to get the latest science into the hands of resource managers entrusted with vulnerable wildland ecosystems. This book examines climate and land-use changes in montane environments, assesses the vulnerability of species and ecosystems to these changes, and provides resource managers with collaborative management approaches to mitigate expected impacts. Climate Change in Wildlands proposes a new kind of collaboration between scientists and managers--a science-derived framework and common-sense approaches for keeping parks and protected areas healthy on a rapidly changing planet.
Download or read book Contrasting Past and Current Numbers of Bears Visiting Yellowstone Cutthroat Trout Streams written by Justin Everette Teisberg and published by . This book was released on 2014 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone's grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non-native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997?2000. We initiated a 3-year study in 2007 to assess whether numbers of spawning fish, black bears, and grizzly bears within and alongside stream corridors had changed since 1997?2000. We estimated numbers of grizzly bears and black bears by first compiling encounter histories of individual bears visiting 48 hair-snag sites along 35 historically fished streams. We analyzed DNA encounter histories with Pradel-recruitment and Jolly-Seber (POPAN) capture-mark-recapture models. When compared to 1997?2000, the current number of spawning cutthroat trout per stream and the number of streams with cutthroat trout has decreased. We estimated that 48 (95% CI?=?42?56) male and 23 (95% CI?=?21?27) female grizzly bears visited the historically fished tributary streams during our study. In any 1-year, 46 to 59 independent grizzly bears (8?10% of estimated Greater Yellowstone Ecosystem population) visited these streams. When compared with estimates from the 1997 to 2000 study and adjusted for equal effort, the number of grizzly bears using the stream corridors decreased by 63%. Additionally, the number of black bears decreased between 64% and 84%. We also document an increased proportion of bears of both species visiting front-country (i.e., near human development) streams. With the recovery of cutthroat trout, we suggest bears that still reside within the Lake basin will readily use this high-quality food resource.
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 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 Predatory Fish Invasion Induces Within and Across Ecosystem Effects in Yellowstone National Park written by Todd M. Koel and published by . This book was released on 2019 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predatory fish introduction can cause cascading changes within recipient freshwater ecosystems. Linkages to avian and terrestrial food webs may occur, but effects are thought to attenuate across ecosystem boundaries. Using data spanning more than four decades (1972?2017), we demonstrate that lake trout invasion of Yellowstone Lake added a novel, piscivorous trophic level resulting in a precipitous decline of prey fish, including Yellowstone cutthroat trout. Plankton assemblages within the lake were altered, and nutrient transport to tributary streams was reduced. Effects across the aquatic-terrestrial ecosystem boundary remained strong (log response ratio ? 1.07) as grizzly bears and black bears necessarily sought alternative foods. Nest density and success of ospreys greatly declined. Bald eagles shifted their diet to compensate for the cutthroat trout loss. These interactions across multiple trophic levels both within and outside of the invaded lake highlight the potential substantial influence of an introduced predatory fish on otherwise pristine ecosystems.
Download or read book Yellowstone Grizzly Bears written by Daniel D. Bjornlie and published by National Park Service Yellowstone National Park. This book was released on 2017 with total page 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 Knowing Yellowstone written by Jerry Johnson and published by Rowman & Littlefield. This book was released on 2010-06-16 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visitors to Yellowstone National Park are drawn to the spectacular scenery, unique thermal features, and the large numbers of wild animals easily observed in their natural habitat. The thoughtful visitor to the park cannot help but be captivated by the unparalleled breadth of scientific knowledge needed to understand the intricate interrelationships that make up the yellowstone landscape. Knowing Yellowstone explores how scientists discover what they know about America's first national park and the surrounding lands. The chapter authors are scientists who represent the best of their fields of study. The science they describe is leading the way to our understanding of complex ecosystems worldwide.
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.
