Author: John D. VarleyPublisher:
ISBN:
Category : Cutthroat trout
Languages : en
Pages : 12
Book Description
Ecology, Status, and Management of the Yellowstone Cutthroat Trout
Author: John D. VarleyPublisher:
ISBN:
Category : Cutthroat trout
Languages : en
Pages : 12
Book Description
Status and Management of Interior Stocks of Cutthroat Trout
Author: Robert E. GresswellPublisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 160
Book Description
The Status, Ecology and Management of the Yellowstone and Snake River Finespotted Cutthroat Trout
Author: John D. VarleyPublisher:
ISBN:
Category : Fishery management
Languages : en
Pages : 7
Book Description
Yellowstone Cutthroat Trout (Oncorhynchus Clarki Bouvieri)
Author: Robert E. GresswellPublisher:
ISBN:
Category : Endangered species
Languages : en
Pages : 148
Book Description
"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
Dynamics of Yellowstone Cutthroat Trout and Lake Trout in the Yellowstone Lake Ecosystem
Author: John Michael SysloPublisher:
ISBN:
Category : Introduced fishes
Languages : en
Pages : 154
Book Description
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.
Yellowstone Fishes
Author: John D. VarleyPublisher: Stackpole Books
ISBN: 9780811727778
Category : Nature
Languages : en
Pages : 170
Book Description
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.
Biology, Status, and Management of Yellowstone Cutthroat Trout
Author: Robert E. GresswellPublisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 31
Book Description
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.
Conservation Assessment for Inland Cutthroat Trout
Author: Donald A. DuffPublisher: DIANE Publishing
ISBN: 0788145673
Category :
Languages : en
Pages : 199
Book Description
This document focuses on the current status, distribution and range for five subspecies of cutthroat trout Oncorhynchus clarki, which are found largely on national forest system lands and ecosystems in the Rocky Mountain and Intermountain West within the U.S. from the Canadian to the Mexican border. The 5 subspecies -- Westslope, Yellowstone, Bonneville, Rio Grande, and Colorado River cutthroat trout -- are designated either species of special concern or sensitive. These subspecies are presently restricted to a fragment of their former range. Includes assessment methods, and origins and taxonomic theory. Illustrated.
Cutthroat
Author: Pat TrotterPublisher: Univ of California Press
ISBN: 9780520254589
Category : Nature
Languages : en
Pages : 572
Book Description
Cutthroat tells the full story of the genuine native trout of the American West. This new edition, thoroughly revised and updated after 20 years, synthesizes what is currently known about one of our most interesting and colorful fishes, includes much new information on its biology and ecology, asks how it has fared in the last century, and looks toward its future. In a passionate and accessibly written narrative, Patrick Trotter, fly fisher, environmental advocate, and science consultant, details the evolution, natural history, and conservation of each of the cutthroat's races and incorporates more personal reflections on the ecology and environmental history of the West's river ecosystems. The bibliography now includes what may be the most comprehensive and complete set of references available anywhere on the cutthroat trout. Written for anglers, nature lovers, environmentalists, and students, and featuring vibrant original illustrations by Joseph Tomelleri, this is an essential reference for anyone who wants to learn more about this remarkable, beautiful, and fragile western native.
Equilibrium Yield and Management of Cutthroat Trout in Yellowstone Lake
Author: Norman Gustaf BensonPublisher:
ISBN:
Category : Cutthroat trout
Languages : en
Pages : 52
Book Description
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.