Download or read book Predicting the Presence of Self sustaining Trout Populations in High Elevation Lakes of Yosemite National Park California written by Daniel Mark Boiano and published by . This book was released on 1999 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self sustainability of Trout Populations in Currently stocked Alpine Lakes in California s Sierra Nevada written by Trip Armstrong and published by . This book was released on 2003 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book South Fork Flathead Watershed Westslope Cutthroat Trout Conservation Program written by and published by . This book was released on 2005 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2004 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interpreting Impacts of Introduced Trout Populations in Mountain Lakes in the Era of Ecological Restoration written by Queenie Z. Gray and published by . This book was released on 2013 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stocking exotic trout species in high mountain lakes was a common practice in Rocky Mountain Lakes in the 20th century. Currently, restoration action to remove trout populations favours the conservation of native food webs. Meanwhile, little is known about the self-sustaining trout populations, particularly in our study area. We assessed impacts of stocking trout on naturally fishless foodwebs of mountain lakes. Results were applied to management goals in Waterton Lakes National Park. A comparison of mean abundances of zooplankton in fish and fishless lakes revealed differences in less than half the taxa encountered. Principle component analysis did not show an association between zooplankton community structure and fish presence. Paleolimnological analyses suggested an increase in relative abundance of large-bodied cladocerans, but statistical power was low. The results show the importance of identifying explicit restoration objectives because impacts may not be compelling. If restoration by trout eradication is pursued, demographic characteristics can aid in selecting which populations are more easily depleted by gillnetting. We used generalized linear models to examine four population characteristics associated with population decline: 1) catch per unit effort (CPUE), 2) proportion of females, 3) proportion of mature individuals and 4) length of mature individuals. There were significant differences between populations in CPUE and length at maturity, but not on the proportion of females or mature individuals. We thus incorporated the former characteristics into a basic assessment system and ranked the 11 salmonid populations by their susceptibility to eradication. We presented a simple yet meaningful step in facilitating management actions commonly constrained by a lack of biological knowledge.
Download or read book Ecological Implications of Trout Introductions to Lakes of the Selway Bitterroot Wilderness Idaho written by Peter F. Bahls and published by . This book was released on 1990 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The widespread introduction of trout to naturally fishless mountain lakes in the western United States has been accompanied by little research. The ecological role of trout populations occurring in 91 lakes of the central Selway Bitterroot Wilderness, Idaho, was examined with respect to 1) the sampling variability of biological and chemical lake characteristics measured, 2) possible effects of trout on biotic communities of crustacean zooplankton, macro-invertebrates, amphibians and reptiles, and 3) the relation of fish population characteristics (condition and maximum body length) to stocking rate, angling pressure, natural recruitment and lake habitat characteristics. Based on 22 lakes surveyed two or three times over a three year period, sampling variability was relatively low for individual species, biotic communities and length and weight of the largest fish in the population. Water conductivity measured at the lake surface from shore was the most reliable index of water quality, exhibiting low seasonal and duplicate sampling variability and a high correlation with alkalinity samples. Based on Detrended Correspondence Analysis (DCA), an ordination method used to organize the 91 lakes by the presence or absence of taxa, the composition of indigenous biotic communities was strongly related to the presence or absence of fish. The Multi-Response Permutation Procedure indicated that the difference in communities was statistically significant. Fewer taxa were sampled in lakes with fish and the taxa expected to be most vulnerable to predation due to their large size and frequent occurrence in open water were rarely found in lakes containing fish. DCA ordinations indicated that characteristics of the fish population (fish species, condition and maximum body length) were also related to the composition of the biotic community. This was probably due to the bottom up:top down trophic level interactions of predator and prey; fish affecting the structure of biotic communities by predation and prey affecting growth and condition of fish by their abundance and availability as determined by both physical habitat characteristics and impacts of predation by fish. Average condition and maximum body length of fish populations were related to stocking rate, natural recruitment, angling pressure and lake habitat variables by stepwise multiple regression. Average condition and maximum body length increased with decreasing level of natural recruitment for all fish population classes, except brook trout (all with high natural recruitment) and populations with no natural recruitment. Average fish condition increased with increasing angling pressure (measured by campsite impact and access distance ratings). Maximum body length of fish increased in relation to habitat variables, particularly presence of the large (2-3 mm) calanoid copepod, Diaptomus sp. Stocking rate was not related to average condition or maximum body length for any fish population class tested except one, where it may represent a spurious correlation. The findings of this study suggest the need to reassess high lake research and management policies that have promoted 1) widespread stocking of un-surveyed lakes on a regular basis and 2) considered stocking rate adjustments as an effective means of manipulating fish populations. Management direction can now be based on a recognition of the potential usefulness of one-time sampling of biological and chemical lake characteristics, the potential for significant impacts of fish on indigenous biotic communities, and the importance of natural recruitment, angling pressure and habitat variables in determining characteristics of the fish population. Recommendations include the identification and maintenance without further stocking of fishless lakes and lakes containing self sustaining trout populations (wild trout lakes).
Download or read book Studies of Trout of Three High Mountain Lakes written by Robert L. Hassur and published by . This book was released on 1961 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Journal of Wilderness written by and published by . This book was released on 2004 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Yosemite Trout Fishing Guide written by Steve Beck and published by Frank Amato Publications. This book was released on 2001-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yosemite National Park is known the world over for its awesome beauty. But this park offers the fisherman more than just a feast for the eyes -- great trout fishing for those who know where, when, and how! In this book, Steve shows you when, where, and how. For each section of the park covered, you'll learn of its history, hatches, weather, regulations, what fish you can expect and how best to catch them, and much more. No trip to this national treasure is complete without it!
Download or read book Conditions of Existence Growth and Longevity of Brook Trout in a Small High altitude Lake of the Eastern Sierra Nevada written by Norman Reimers and published by . This book was released on 1958 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Estimates of Abundance and Distribution of Spawning Lake Trout on Sheboygan Reef in Lake Michigan written by David M. Warner and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Efforts to restore self-sustaining lake trout (Slavelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study eggs and fry, it is necessary to identify spawning locations, which is difficult in deep water. Acoustic sampling can be used to rapidly locate aggregations of fish (like apwning lake trout), we conducted an acoustic survey covering 22 km (2) at Sheboygan Reef, a deep reef (
Download or read book Topographic Index Modeling of Young of year Brook Trout Salvelinus Fontinalis Habitat and Selecting Candidate Lakes for Wild Brook Trout Re Introduction written by Peter Merritt Stevens and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adirondack brook trout (Salvelinus fontinalis) depend on locations of groundwater upwelling for spawning, nursery habitat and thermal refugia for both young-of-year (YOY) and adult fish. Landscape-scale anthropogenic disturbances, such as logging and road construction, have the potential to influence brook trout habitat by altering these groundwater regimes. We used a topographic index (TI) approach to link watershed-scale topography with groundwater-influenced tributaries and seeps and YOY brook trout presence in the littoral zone of three lakes in the Adirondack Mountains, NY. The TI value of shoreline locations was positively associated with the temperature difference between lake surface and substrate, indicating greater groundwater seepage at locations with a higher TI value. The TI value of shoreline locations was also positively correlated with YOY brook trout presence in the nearshore zone. TI represented a significant improvement in predictive capability over currently available groundwater-influenced habitat location and delineation methods. Akaike's information criterion indicated that TI value was the strongest predictor of: (1) the presence of groundwater-influenced tributaries or seeps, and (2) YOY brook trout presence and numerical abundance in the nearshore zone. However, TI-based metrics were unable to predict brook trout population reproductive status or density at an inter-lake scale, possibly because the effects of acid precipitation are the primary drivers of variability in brook trout population abundance at a regional scale within the Adirondacks. The TI model represents a useful management tool at the scale of an individual lake shoreline, but further refinement is required for applications at an inter-lake scale.
Download or read book Distribution and Population Characteristics of Lake Trout in Lake McDonald Glacier National Park written by Andrew Martin Dux and published by . This book was released on 2005 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bull trout Salvelinus confluentus have declined since the establishment of nonnative lake trout Salvelinus namaycush in Lake McDonald, Glacier National Park (GNP). In an attempt to prevent further decline of this population, GNP is considering implementing a lake trout suppression program. I used ultrasonic telemetry to examine the spatial and temporal distribution of lake trout and gill nets to evaluate population characteristics and diet. Model simulations were used to predict lake trout responses to varying levels of suppression. I relocated 36 lake trout (508-859 mm total length) 1,137 times from June through November 2003 and March through November 2004. Lake trout had a narrow vertical distribution during all seasons in both 2003 and 2004, rarely occupying depths>30 m. During thermal stratification, lake trout occupied depths in the upper hypolimnion where mean temperature varied from 8-9°C and dissolved oxygen was highest. Lake trout typically were suspended in the water column during all seasons except autumn. When spawning commenced in late-October, lake trout were associated with littoral habitats containing clean cobble and boulder substrates. The lake trout population had a broad age structure and a maximum age of 37 years. Males reached maturity earlier (12 years) than females (15 years), and total annual mortality rate for lake trout ages 8-27 was 13.2%. Growth rates were slow and relative weight values were among the lowest observed for lake trout throughout their range. Food habits were sampled from 254 lake trout, and 95% of the diet by weight consisted of fish prey. Model simulations indicated that substantial population reduction could be achieved with moderate exploitation (20-50%); however, this was more easily achieved as the size at which lake trout could effectively be captured was reduced. Simulations suggested that recruitment could be reduced to a level where adults are not being replaced at low exploitation (10-30%). These data will allow suppression efforts to be focused at times and places that will maximize efficiency, and population simulations suggest that substantial reduction of the lake trout population is feasible. Ultimately, results from this study should promote recovery of bull trout in Lake McDonald.
Download or read book Ecosystems of California written by Harold Mooney and published by Univ of California Press. This book was released on 2016-01-19 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt: This long-anticipated reference and sourcebook for CaliforniaÕs remarkable ecological abundance provides an integrated assessment of each major ecosystem typeÑits distribution, structure, function, and management. A comprehensive synthesis of our knowledge about this biologically diverse state, Ecosystems of California covers the state from oceans to mountaintops using multiple lenses: past and present, flora and fauna, aquatic and terrestrial, natural and managed. Each chapter evaluates natural processes for a specific ecosystem, describes drivers of change, and discusses how that ecosystem may be altered in the future. This book also explores the drivers of CaliforniaÕs ecological patterns and the history of the stateÕs various ecosystems, outlining how the challenges of climate change and invasive species and opportunities for regulation and stewardship could potentially affect the stateÕs ecosystems. The text explicitly incorporates both human impacts and conservation and restoration efforts and shows how ecosystems support human well-being. Edited by two esteemed ecosystem ecologists and with overviews by leading experts on each ecosystem, this definitive work will be indispensable for natural resource management and conservation professionals as well as for undergraduate or graduate students of CaliforniaÕs environment and curious naturalists.
Download or read book Merced Wild and Scenic River Comprehensive Management Plan written by and published by . This book was released on 2000 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Managing California s Water written by Ellen Hanak and published by Public Policy Instit. of CA. This book was released on 2011 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
