Download or read book Population Dynamics and Trophic Ecology of Nonnative Lake Trout in Priest Lake Idaho written by Elizabeth L. Ng and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonnative Lake Trout have provided a recreational fishery in Priest Lake, Idaho, since their introduction in 1925. However, changes in the fish assemblage, declines in Lake Trout body condition, and negative interactions between Lake Trout and fishes of conservation and economic importance have prompted questions about future management goals for this Lake Trout population. Given the lack of fishery-independent information, I evaluated the demographics and trophic ecology of Lake Trout in Priest Lake. I used age-structured population models to synthesize biological information and evaluate the feasibility and trade-offs associated with eradication, trophy, and balance management scenarios. I also used stable isotope analysis to evaluate Lake Trout in a food-web context. These studies contribute directly to effective management of Lake Trout in Priest Lake, and more broadly, to our understanding of Lake Trout populations throughout North America.

Download or read book Population Dynamics and Evaluation of Alternative Management Strategies for Nonnative Lake Trout in Priest Lake Idaho written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Population Dynamics and Trophic Ecology of Northern Pike and Smallmouth Bass in Coeur D Alene Lake written by John David Walrath and published by . This book was released on 2013 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adfluvial Westslope Cutthroat Trout Oncorhynchus clarkii lewisi populations have declined significantly since the 1900s in Coeur d'Alene Lake, Idaho. The Coeur d'Alene Tribe has an intense Passive Integrated Transponder (PIT) tagging program and has reported poor juvenile to adult return rates, which is hypothesized to be a result of predation by nonnative species, such as Northern Pike Esox lucius and Smallmouth Bass Micropterus dolomieu . Sampling occurred on 138 days and 15,645 individual fishes representing 24 species were captured. The population structure and dynamics of Northern Pike and Smallmouth Bass were similar across sampling locations. After pooling data for Coeur d'Alene Lake, growth of Northern Pike and Smallmouth Bass was compared using meta-analysis to other populations across their distributions. The potential effect of predation by Northern Pike on Westslope Cutthroat Trout was evaluated with bioenergetics modeling. Northern Pike (i.e., 2008-2011 year classes) consume an estimated 5,641 Westslope Cutthroat Trout annually from the four sampling locations (i.e., Cougar, Wolf Lodge, Windy bays, Benewah Lake) in Coeur d'Alene Lake.

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 A Study of the Population Dynamics and Trophic Ecology of the Brook Trout in Two Subalpine Lakes in Southeastern Wyoming written by Thomas R. Garofalo and published by . This book was released on 1964 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Trophic Ecology of Lake Trout Salvelinus Namaycush in Flaming Gorge Reservoir Utah Wyoming written by Thomas C. Roberts and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lake Trout (Salvelinus namaycush) are apex predators that were first introduced into Flaming Gorge Reservoir, Utah-Wyoming in 1979 and have been self-sustaining since 1989. However, our understanding of their trophic ecology and subsequent effects on other fish species within this reservoir is limited. I assessed feeding dynamics of Lake Trout through traditional diet analyses and stable isotope analyses of muscle and liver tissues, and compare these outputs to patterns of Lake Trout growth rates and size structure. By integrating Lake Trout feeding dynamics with population demographics, I infer potential impacts of Lake Trout predation on prey fish. Lake Trout consumed a wide breadth of prey items across their ontogeny, but consumed a higher proportion of fish as their length increased. Stable isotope analyses suggested a higher reliance on fish prey than was described by stomach content analysis; however, estimates of feeding dynamics were comparable across methods. Growth models suggest that Lake Trout exhibited two distinct growth trajectories which indicate a divergent foraging strategy among individuals. I conclude that Lake Trout predation could be an important driver of game and non-game fish populations. While more information is needed, results suggest current length class definitions used for Lake Trout harvest regulations may not reflect observed ecological breakpoints. Further research such as bioenergetics modeling and fishing related mortality estimates are needed to fully understand ecological dynamics of this apex predator within Flaming Gorge Reservoir.

Download or read book Interactions Between Lake Trout and Bull Trout in the Priest Lake System Idaho written by Derek C. Entz and published by . This book was released on 2017 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 2. "The effects and impacts introduced species have on native species is well known in some cases and less well for others. The introduction and success of Lake Trout in the Priest Lake system, in Idaho, poses a threat to native fish populations. In an effort to further understand the potential competition and predation on native species in Upper Priest Lake, 283 stomachs were collected from Lake Trout in 2015 and 2016. Small Lake Trout (500 mm total length (TL)) fed at a significantly higher rate on Mysis shrimp (Mysis diluviana) than larger Lake Trout (500 mm TL; P0.001). Larger Lake Trout (500 mm TL) fed at a significantly higher rate on fish than small Lake Trout (P

Download or read book Ecology of Lacustrine adfluvial Bull Trout Populations in an Interconnected System of Natural Lakes written by Michael Hendrik Meeuwig and published by . This book was released on 2008 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Loss of connectivity among populations and interactions with nonnative species can negatively influence abundance of bull trout Salvelinus confluentus. Connectivity among bull trout populations and trophic relationships among native and nonnative fishes in Glacier National Park (GNP), Montana, were examined. Competition between juvenile (or equal to 80 mm) bull trout and lake trout S. namaycush for cover habitat was examined in a laboratory environment. Connectivity among bull trout populations was inferred from genetic data. Barriers (i.e., waterfalls or equal to 1.8 m) reduced genetic diversity and increased genetic differentiation among populations. Genetic differentiation was positively related to the length of tributary stream sections between populations and populations within the same drainage were more similar than populations in different drainages. Competition between bull trout and nonnative lake trout for prey is a potential mechanism for declines in bull trout abundance. Stable isotopes analyses were used to examine trophic relationships among fishes in GNP lakes. Bull trout and lake trout were top-level predators among lakes (Delta15N analysis), lake trout occupied a higher trophic position than bull trout (Delta15N analysis), and bull trout and lake trout likely used different foraging habitats (Delta13C analysis). These data do not support the prediction that these species are complete competitors for prey resources in GNP. Cover habitat protects fish from predators and is competed for if limiting. Habitat use by juvenile bull trout and lake trout was experimentally evaluated. Bull trout and lake trout differed in habitat use. Lake trout avoided bottom habitat, bull trout avoided water column habitat when lake trout were present, and neither species selected cover habitat. The hypothesis that bull trout and lake trout compete for cover habitat was not supported. The landscape in GNP allows connectivity among bull trout populations that are not isolated by barriers and one-way dispersal past waterfalls is likely. This connectivity allows dispersal and colonization by nonnative fishes into GNP lakes. Bull trout and nonnative lake trout are not complete competitors for prey resources in GNP or cover habitat; however, future studies should examine trophic shifts by these species associated with prey limitation and diel variability in habitat use by these species.

Download or read book Feeding Ecology of Native and Nonnative Salmonids During the Expansion of a Nonnative Apex Predator in Yellowstone Lake Yellowstone National Park written by John M. Syslo and published by . This book was released on 2016 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The illegal introduction of Lake Trout Salvelinus namaycush into Yellowstone Lake, Yellowstone National Park, preceded the collapse of the native population of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri, producing a four-level trophic cascade. The Yellowstone Cutthroat Trout population?s collapse and the coinciding increase in Lake Trout abundance provided a rare opportunity to evaluate the feeding ecology of a native prey species and a nonnative piscivore species after the restructuring of a large lentic ecosystem. We assessed diets, stable isotope signatures, and depth-related CPUE patterns for Yellowstone Cutthroat Trout and Lake Trout during 2011?2013 to evaluate trophic overlap. To evaluate diet shifts related to density, we also compared 2011?2013 diets to those from studies conducted during previous periods with contrasting Yellowstone Cutthroat Trout and Lake Trout CPUEs. We illustrate the complex interactions between predator and prey in a simple assemblage and demonstrate how a nonnative apex predator can alter competitive interactions. The diets of Yellowstone Cutthroat Trout were dominated by zooplankton during a period when the Yellowstone Cutthroat Trout CPUE was high and were dominated by amphipods when the CPUE was reduced. Lake Trout shifted from a diet that was dominated by Yellowstone Cutthroat Trout during the early stages of the invasion to a diet that was dominated by amphipods after Lake Trout abundance had increased and after Yellowstone Cutthroat Trout prey had declined. The shifts in Yellowstone Cutthroat Trout and Lake Trout diets resulted in increased trophic similarity of these species through time due to their shared reliance on benthic amphipods. Yellowstone Cutthroat Trout not only face the threat posed by Lake Trout predation but also face the potential threat of competition with Lake Trout if amphipods are limiting. Our results demonstrate the importance of studying the long-term feeding ecology of fishes in invaded ecosystems.

Download or read book Investigating Trophic Ecology and Dietary Niche Overlap Among Morphs of Lake Trout in Lake Superior written by Justin Michael Hoffmann and published by . This book was released on 2017 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Handbook of Global Freshwater Invasive Species written by Robert A. Francis and published by Routledge. This book was released on 2017-08-11 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invasive non-native species are a major threat to global biodiversity. Often introduced accidentally through international travel or trade, they invade and colonize new habitats, often with devastating consequences for the local flora and fauna. Their environmental impacts can range from damage to resource production (e.g. agriculture and forestry) and infrastructure (e.g. buildings, road and water supply), to human health. They consequently can have major economic impacts. It is a priority to prevent their introduction and spread, as well as to control them. Freshwater ecosystems are particularly at risk from invasions and are landscape corridors that facilitate the spread of invasives. This book reviews the current state of knowledge of the most notable global invasive freshwater species or groups, based on their severity of economic impact, geographic distribution outside of their native range, extent of research, and recognition of the ecological severity of the impact of the species by the IUCN. As well as some of the very well-known species, the book also covers some invasives that are emerging as serious threats. Examples covered include a range of aquatic and riparian plants, insects, molluscs, crustacea, fish, amphibians, reptiles and mammals, as well as some major pathogens of aquatic organisms. The book also includes overview chapters synthesizing the ecological impact of invasive species in fresh water and summarizing practical implications for the management of rivers and other freshwater habitats.

Download or read book An Ecological Characterization of Rocky Mountain Montane and Subalpine Wetlands written by and published by . This book was released on 1986 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Management Policies written by United States. National Park Service and published by . This book was released on 1988 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biology and Control of Aquatic Plants written by Lyn A. Gettys and published by . This book was released on 2009 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biology and Control of Aquatic Plants: A Best Management Practices Handbook is the fourth edition of a handbook produced by the not for profit Aquatic Ecosystem Restoration Foundation (AERF). The mission of the AERF is to support research and development which provides strategies and techniques for the environmentally and scientifically sound management, conservation and restoration of aquatic ecosystems. One way the Foundation accomplishes this mission is by producing this handbook to provide information to the public regarding the benefits of aquatic ecosystem conservation and aquatic plant management. The first, second and third editions of this handbook became some of the most widely consulted references in the aquatic plant management community. This fourth edition has been specifically designed with water resource managers, water management associations, homeowners and customers and operators of aquatic plant management companies and districts in mind. Our goal in preparing this handbook is to provide basic, scientifically sound information to assist decision-makers with their water management questions.

Download or read book Forest Roads A Synthesis of Scientific Information written by and published by DIANE Publishing. This book was released on 2001 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sex Control in Aquaculture written by Hanping Wang and published by John Wiley & Sons. This book was released on 2018-11-08 with total page 1969 pages. Available in PDF, EPUB and Kindle. Book excerpt: Awarded Bookauthority's "Best Aquaculture Books of all Time" A comprehensive resource that covers all the aspects of sex control in aquaculture written by internationally-acclaimed scientists Comprehensive in scope, Sex Control in Aquaculture first explains the concepts and rationale for sex control in aquaculture, which serves different purposes. The most important are: to produce monosex stocks to rear only the fastest-growing sex in some species, to prevent precocious or uncontrolled reproduction in other species and to aid in broodstock management. The application of sex ratio manipulation for population control and invasive species management is also included. Next, this book provides detailed and updated information on the underlying genetic, epigenetic, endocrine and environmental mechanisms responsible for the establishment of the sexes, and explains chromosome set manipulation techniques, hybridization and the latest gene knockout approaches. Furthermore, the book offers detailed protocols and key summarizing information on how sex control is practiced worldwide in 35 major aquaculture species or groups, including fish and crustaceans, and puts the focus on its application in the aquaculture industry. With contributions from an international panel of leading scientists, Sex Control in Aquaculture will appeal to a large audience: aquaculture/fisheries professionals and students, scientists or biologists working with basic aspects of fish/shrimp biology, growth and reproductive endocrinology, genetics, molecular biology, evolutionary biology, and R&D managers and administrators. This text explores sex control technologies and monosex production of commercially-farmed fish and crustacean species that are highly in demand for aquaculture, to improve feed utilization efficiency, reduce energy consumption for reproduction and eliminate a series of problems caused by mixed sex rearing. Thus, this book: Contains contributions from an international panel of leading scientists and professionals in the field Provides comprehensive coverage of both established and new technologies to control sex ratios that are becoming more necessary to increase productivity in aquaculture Includes detailed coverage of the most effective sex control techniques used in the world's most important commercially-farmed species Sex Control in Aquaculture is the comprehensive resource for understanding the biological rationale, scientific principles and real-world practices in this exciting and expanding field.

Download or read book Ecological Literature and the Critique of Anthropocentrism written by Bryan L. Moore and published by Springer. This book was released on 2017-10-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an analysis of literary texts that question, critique, or subvert anthropocentrism, the notion that the universe and everything in it exists for humans. Bryan Moore examines ancient Greek and Roman texts; medieval to twentieth-century European texts; eighteenth-century French philosophy; early to contemporary American texts and poetry; and science fiction to demonstrate a historical basis for the questioning of anthropocentrism and contemplation of responsible environmental stewardship in the twenty-first century and beyond. Ecological Literature and the Critique of Anthropocentrism is essential reading for ecocritics and ecofeminists. It will also be useful for researchers interested in the relationship between science and literature, environmental philosophy, and literature in general.