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 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 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 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 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 Predicting Year class Abundance of Yellowstone Lake Cutthroat Trout written by Ross V. Bulkley and published by . This book was released on 1962 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluctuations in strength of year classes from 1945 to 1956 of Yellowstone Lake cutthroat from Pelican and Chipmunk Creeks are compared with the parental stock and several climatically influenced factors of the environment. Variations in year-class strength in the two tributaries were highly correlated with fluctuations in lake water levels. Strong year classes occurred in yeas of low water. Female spawner escapement, timing of the runs, and summer air temperatures were not significant factors. A formula based on water levels is presented for predicting year-class strength in Pelican Creek and in the Fishing Bridge area fishery. Stocking of fry in years of high water is suggested as a means of supplementing natural production. A method of forecasting lake water levels several months in advance of their occurrence is discussed.

Download or read book Revised Bibliography on the Cutthroat Trout written by Oliver B. Cope and published by . This book was released on 1964 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper is a compilation of 221 abstracts of publications on the biology, culture, distribution, and management of the cutthroat trout, Salmo clarki Richardson. The 1958 publication, "Annotated Bibliography on the Cutthroat Trout," contained 135 abstracts, which have been incorporated with recent ones to form the present report.

Download or read book Hooking Mortality of the Yellowstone Cutthroat Trout Salmo Clarki Lewisi in Yellowstone Lake written by Don Hunsaker and published by . This book was released on 1965 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: INn the ten years from 1950 to 1960, the number of annual angling hours on Yellowstone Lake, Wyoming, increased from 191,989 to 407,327. In 1964, a total of 488,563 hours of anglers effort was recorded. The shoreline fishery by itself accounted for 167,704 anglers. This increase in angler effort has been accompanied by a greater harvest of fish and is characteristic of the increased sportfishing pressure throughout the United States. With an expanding human population the sport of fishing is continually gaining popularity and growing concern has been voiced in recent years about the gradual depletion of our sport fishery resources due to angler take. In Yellowstone, the importance of greater conservation effort is evidenced by the fact that some 20,000 cutthroat trout were discarded to waste in 1959. Either larger numbers of catchable size fish must be made available or some practical method of conserving individual fish must be developed without detracting from the purely sporting aspects of angling. A potentially rewarding solution to this problem is the possibility of instigating an effective "Fishing-for-Fun" philosophy where anglers would catch fish for the sport of it and immediately return them to the water. Although this idea was initiated in Yellowstone National Park in 1960, in practice, public acceptance and biological benefit have not been measured. This proposed project will establish the feasibility of a large scale catch and return fishing program at Yellowstone lake and contribute significant data to similar programs in other fresh water areas. The research will be under the direction of Don Hunsaker II and F. Phillip Sharpe. All the important factors of the problem will be considered and tested. The project will begin in January, 1966, and extend for a period of three years until December, 1968.

Download or read book Natural Variation in Spotting Hyoid Teeth Counts and Coloration of Yellowstone Cutthroat Trout written by Ross V. Bulkley and published by . This book was released on 1963 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Differences in hyoid teeth and spotting counts among samples from four related populations of Yellowstone cutthroat trout, Salmo clarki lewisi Girard, reached species and subspecies levels as defined by some workers. Body coloration varied significantly among fish in six spawning runs of Yellowstone Lake, Wyo. The use of coloration, spotting, and hyoid teeth counts in cutthroat trout for taxonomic purposes needs reevalution.

Download or read book Age Growth Maturity and Fecundity of Yellowstone Lake Cutthroat Trout written by Lynn Robert Kaeding and published by . This book was released on 2011 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demographic data are sparse for Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri; YCT). Data for YCT in the spawning run (spring; 29 years) of a Yellowstone Lake tributary or caught in gill nets set (fall; 30 years) at established lake locations between 1977 and 2007 were examined. Female proportion in runs averaged 0.61 but was 0.48 among gillnetted "prespawner" YCT (i.e., mature fish whose excised gonads indicated the fish would have spawned the next year). Maturity proportion-total length (TL) relationships for gillnetted female and male YCT were logistic-shaped and similar in their inflection points; maturity onset occurred at 200?250 mm TL; ~95% of YCT [greater than or equal to] 400 mm TL were mature and 70% were prespawners. Fecundity was positively associated with YCT TL. Accuracy of scale-based YCT ages was affected by a frequently overlooked scale annulus and an inability to unequivocally identify fish of a single cohort on the basis of scale characteristics using associated, recognized ageing criteria for this population. Temporal differences in fits of a modified von Bertalanffy growth model to YCT TL at capture and scale-based age probably resulted from ageing errors evident among successive, annual scale analysts rather than differences in YCT growth. Nevertheless, when the age estimates of one, long-term analyst were used in analyses, the estimated growth parameters L[infinity] and [omega] were concordant with empirical observations of the maximum TL of YCT and TL of age-1 YCT in Yellowstone Lake, respectively. The demographic relationships and linking, parameterized growth model provide a useful foundation for age-structured population modeling.

Download or read book Yellowstone Lake Trout Creel Census 1950 51 written by Harvey L. Moore and published by . This book was released on 1952 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Demography of Lake Trout in Relation to Population Suppression in Yellowstone Lake Yellowstone National Park written by John Michael Syslo and published by . This book was released on 2010 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduced lake trout Salvelinus namaycush threaten to extirpate native Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri in Yellowstone Lake, Yellowstone National Park. Suppression of the lake trout population is deemed necessary for the conservation of Yellowstone cutthroat trout. A National Park Service gill netting program removed nearly 273,000 lake trout from Yellowstone Lake between 1995 and 2007. Lake trout population size has not been estimated; therefore, it is difficult to determine the efficacy of the program (i.e., proportion of the population that has been removed). My objectives were to (1) examine catch per unit effort (C/f) through time and catch as a function of effort to determine if the suppression program has caused lake trout abundance to decline, (2) determine if length structure, age structure, individual growth, mortality, body condition, length at maturity, age at maturity, and fecundity have changed as a function of harvest, and (3) develop age-structured models to determine the level of mortality required to cause population growth rate to decline below 1.0 (replacement). An increase in lake trout abundance was indicated by increasing C/f over time. Additionally, catch has continued to increase as a function of effort, indicating lake trout abundance is increasing. Population metrics were not clearly indicative of a response to harvest. However, metrics were comparable to North American lake trout populations where harvest has occurred, indicating that lake trout have not reached carrying capacity in Yellowstone Lake. Results from an age-structured matrix model determined the rate of population growth was 1.1 given the current rate of fishing mortality and that population growth rate would be 1.3 in the absence of fishing mortality. The current rate of population growth is positive; however, it is slower than it would be in the absence of lake trout suppression. Fishing mortality needs to increase from the rate of 0.22 estimated in 2007 to at least 0.32 to reduce population growth rate below replacement. Lake trout suppression is becoming an increasingly common management practice throughout the Intermountain West. Thus, Yellowstone Lake provides a case study for evaluating a strategy to remove the apex predator from a large lake.

Download or read book Environmental Factors and Egg Mortality of Cutthroat Trout S a l m o C l a r k i in Three Tributaries of Yellowstone Lake written by LeRoy Edwin Mills and published by . This book was released on 1966 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Six Years of Catch Statistics on Yellowstone Lake written by Oliver B. Cope and published by . This book was released on 1957 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U. S. Fish and Wildlife Service collected catch statistics on Yellowstone Lake and adjacent waters from 1950 to 1955 as part of an investigation on the status of the cutthroat trout fishery and the fish populations. Methods for estimating numbers of fishermen, hours of effort, and catch, were developed for each unit of the fishery and were used to compute estimates for all years of the 6-year period. -- First paragraph.

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 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.