Download or read book Analysis of Food Web Effects of Non native Fishes and Evaluation of Stream Restoration Potential for the San Rafael River Utah written by Timothy E. Walsworth and published by . This book was released on 2011 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: PUBLIC ABSTRACT: Native fishes of the Colorado River Basin have experienced dramatic reductions in range and abundance as a result of extensive human alterations to the basin's waterways. Many of these native fishes are federally listed under the Endangered Species Act, while several others are subject to range-wide conservation agreements between state and federal management agencies. Three of the native species subject to range-wide conservation agreements are the flannelmouth sucker, bluehead sucker, and roundtail chub (hereafter, the "three species"). Each of the "three species" is still found in the San Rafael River of southeastern Utah, which has experienced habitat degradation and non-native species establishment representative of many desert streams. In this study, I examined the effects of non-native species on the food web structure and relative growth rates of the "three species" (Chapter 2) in two sections of the river characterized by the presence and absence of non-native fish. I found that the presence of non-native species lengthens the food chain, presenting new predators and competitors to the 'three species.' However, I found no evidence of reduced growth in the presence of these non-native fishes, likely due to movement of individuals of the "three species" between the two sections of river. Secondly, I developed a model to identify and rank limiting factors to the "three species" along the continuum of the lower river. Finally, I used this model to simulate and predict the relative effect of different restoration actions at different locations along the river on the abundance of the 'three species.' These models predicted that removal of non-native fishes and the restoration of long stretches of suitable habitat would be most beneficial to the 'three species.' Models such as those developed in this study can be useful for management agencies to prioritize restoration efforts to ensure the persistence of the "three species" both in the San Rafael River and throughout their historic range.
Download or read book Analysis of food web effects of non native fishes and evaluation of restoration potential for the San Rafael River Utah written by Timothy E. Walsworth and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Flooding and Tamarisk Removal on Habitat for Sensitive Fish Species in the San Rafael River Utah written by Daniel Louis Keller and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I of this report is focused on assessment of habitat changes on the San Rafael River after the abnormally high water year in 2011. Having habitat data and aerial imagery collected in 2010 (pre-flood) provided an opportunity to assess how a flood of this magnitude changed river habitat. In 2011 we commissioned a second aerial flight of the San Rafael River to serve as post flood imagery, then used Geographic Information Systems (GIS, ArcMap 10) to analyze river changes due to tamarisk removal and flooding. Our tamarisk removal project appears to have increased the potential for spring floods to diversify river habitat. The lack of complex habitat (pools, riffles, backwaters) is a limiting factor for native fish in the lower San Rafael River. Part I of this report also includes investigations into the importance of large woody debris (LWD) in creation of complex river habitat. Pools, riffles, and backwaters occurred more frequently within 30 m up and down stream of LWD piles (LWD buffers) compared to areas within 30 m of random points (random buffers). In addition to a greater number of pools around LWD, the pools inside LWD buffers were also significantly larger than those associated with the random buffers. The size of riffle and backwater habitat was not significantly different between the LWD buffers and the random buffers. LWD piles strongly influence the formation and distribution of complex habitat along the lower San Rafael River. Due to the importance of LWD in creating complex habitat and thermal refuge, several management options are discussed that would increase the LWD in the San Rafael River. Part I primarily covers the ecological component of this study, however the recommendations section of Part I discusses some of the policy and economic issues concerning restoration of the San Rafael River. Part II of the report will include human dimension, policy, and economic aspects of restoration efforts on the San Rafael River. Here we evaluate how water use could be impacted by further declines in native fish species and how potential listing of the 0́8three species0́9 would affect water users in the San Rafael River Drainage. The roundtail chub (Gila robusta) has been petitioned for listing under the Endangered Species Act in the Lower Colorado Basin. If roundtail chub were listed in the Upper Colorado Basin, the San Rafael River could be listed as critical habitat for recovery of the species. Part II also consists of a literature review of the current research available on the San Rafael River. The literature review is a synthesis of past research that illustrates the importance and need for restoration of the San Rafael River. Part II also identifies future research needs, such as evaluating the reintroduction of beaver as a restoration technique. This section will also discuss the pros and cons of current and proposed management practices, as well as identify how changes in local water policy and management could benefit native fish populations of the San Rafael River. Many of the proposed management practices such as installing more efficient irrigation systems, and working with water users to coordinate release of water in the spring time, will assist in the large undertaking of providing more flows for the benefit of native fish. The economic and ecological aspects of various tamarisk control methods is discussed with costs given for the current methods of tamarisk control being used on the San Rafael River.
Download or read book Food Web Structure and Variation in the Gila River USA written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The upper Gila River basin in southwest New Mexico, USA is one of the few unimpounded drainage basins in North America and is a stronghold for the unique and endemic fishes west of the Continental Divide. Multiple non-indigenous fishes have been introduced to the Gila River and are a potential threat to native fishes, yet very little is known of the trophic ecology of the native and nonnative fishes. We used diet and stable isotopes collected from native and nonnative fishes to identify their trophic relationships and evaluate potential interactions in the upper Gila River basin during June-July, 2007 and 2008. Diet and stable isotope data indicated aquatic invertebrates were the primary food for both native and nonnative fishes. Native large-bodied fishes were mainly algivore/detritivores and native small-bodied fishes were primarily insectivores. Small-bodied nonnative fishes fed on detritus and aquatic invertebrates. Nonnative predators preyed on small-bodied fishes and predaceous aquatic invertebrates and had higher trophic positions than all native fishes. Although nonnative predators did not rely exclusively on native fishes as prey, their presence extended community food-chain lengths, and the combined predation on juvenile native fishes by multiple apex predators may threaten persistence of native fishes. The lack of concise evidence for negative effects suggested that impacts of nonnative predators were more subtle and confirmed the underlying complexity of a relatively simple community The extensive database on feeding relations of Gila River fishes allowed us to further understand how energy moves through ecosystems. Specifically, the goal of chapter two was to characterize variation in fish-community food web structure within and among study reaches on the Gila River using [superscript]13C and [superscript]15N stable isotopes. We hypothesized that food web structure would reflect variation in fish community structure, resource availability and environmental conditions across habitats. Food web structure in isotope bi-plot space was estimated using community-wide measures of trophic structure, mean trophic position, and food-chain length. Permutational multivariate analysis of variance indicated that indices of food web structure were more variable among than within reaches and this pattern was primarily associated with variation in trophicl area occupied by taxa in isotope bi-plot space and mean trophic position of those taxa. Variation in food web structure was significantly associated with fish species richness across macrohabitats but was weakly associated with abiotic reach-scale factors. Variation in food web structure was concordant with variation in fish community composition and suggested that factors influencing the distribution of fishes also influence food web structure.
Download or read book Proposed Experimental Releases from Glen Canyon Dam and Removal of Non native Fish written by and published by . This book was released on 2002 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental releases of water from Glen Canyon Dam to conserve fine sediments and reduce non-native fish will be combined with mechanical removal of non-native fish to benefit native fish, particularly the endangered humpback chub.
Download or read book Assessment of Effects of Altered Stream Flow Characteristics on Fish and Wildlife California Executive summary Final report Case studies written by and published by . This book was released on 1976 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Battle Against Extinction written by W. L. Minckley and published by University of Arizona Press. This book was released on 2017-08-15 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1962 the Green River was poisoned and its native fishes killed so that the new Flaming Gorge Reservoir could be stocked with non-native game fishes for sportsmen. This incident was representative of water management in the West, where dams and other projects have been built to serve human needs without consideration for the effects of water diversion or depletion on the ecosystem. Indeed, it took a Supreme Court decision in 1976 to save Devils Hole pupfish from habitat destruction at the hands of developers. Nearly a third of the native fish fauna of North America lives in the arid West; this book traces their decline toward extinction as a result of human interference and the threat to their genetic diversity posed by decreases in their populations. What can be done to slow or end this tragedy? As the most comprehensive treatment ever attempted on the subject, Battle Against Extinction shows how conservation efforts have been or can be used to reverse these trends. In covering fishes in arid lands west of the Mississippi Valley, the contributors provide a species-by-species appraisal of their status and potential for recovery, bringing together in one volume nearly all of the scattered literature on western fishes to produce a monumental work in conservation biology. They also ponder ethical considerations related to the issue, ask why conservation efforts have not proceeded at a proper pace, and suggest how native fish protection relates to other aspects of biodiversity planetwide. Their insights will allow scientific and public agencies to evaluate future management of these animal populations and will offer additional guidance for those active in water rights and conservation biology. First published in 1991, Battle Against Extinction is now back in print and available as an open-access e-book thanks to the Desert Fishes Council.
Download or read book Maintaining Population Persistence in the Face of an Extremely Altered Hydrograph written by Jared L. Bottcher and published by . This book was released on 2009 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability of an organism to disperse to suitable habitats, especially in modified and fragmented systems, determines individual fitness and overall population viability. The bluehead sucker (Catostomus discobolus), flannelmouth sucker (Catostomus latipinnis), and roundtail chub (Gila robusta) are three species native to the upper Colorado River Basin that now occupy only 50% of their historic range. Despite these distributional declines, populations of all three species are present in the San Rafael River, a highly regulated tributary of the Green River, Utah, providing an opportunity for research. Our goal was to determine the timing and extent of movement, habitat preferences, and limiting factors, ultimately to guide effective management and recovery of these three species. In 2007-2008, we sampled fish from 25 systematically selected, 300-m reaches in the lower 64 km of the San Rafael River, spaced to capture the range of species, life-stages, and habitat conditions present. We implanted all target species with a passive integrated transponder (PIT) tag, installed a passive PIT tag antennae, and measured key habitat parameters throughout each reach and at the site of native fish capture. We used random forest modeling to identify and rank the most important abiotic and biotic predictor variables, and reveal potential limiting factors in the San Rafael River. While flannelmouth sucker were relatively evenly distributed within our study area, highest densities of roundtail chub and bluehead sucker occurred in isolated, upstream reaches characterized by complex habitat. In addition, our movement and length-frequency data indicate downstream drift of age-0 roundtail chub, and active upstream movement of adult flannelmouth sucker, both from source populations, providing the lower San Rafael River with colonists. Our random forest analysis highlights the importance of pools, riffles, and distance-to-source populations, suggesting that bluehead sucker and roundtail chub are habitat limited in the lower San Rafael River. These results suggest management efforts should focus on diversifying habitat, maintaining in-stream flow, and removing barriers to movement.
Download or read book Assessment of Effects of Altered Stream Flow Characteristics on Fish and Wildlife written by and published by . This book was released on 1977 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Secondary Production Rates Consumption Rates and Trophic Basis of Production of Fishes in the Colorado River Grand Canyon AZ written by Kevin Christopher Donner and published by . This book was released on 2011 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Regulation of the flows of large rivers has contributed to the decline and extirpation of native fishes worldwide. The impact of altered physical habitats on fishes in these rivers is well studied however, the potential impact of altered food resources and competition for food is relatively unknown. I investigate fish assemblage secondary production rates, consumption rates, trophic basis of production, and coefficients of potential competition for food in a regulated section of the Colorado River. Simuliidae and Chironomidae fueled 41-57% of secondary production by the entire fish assemblage at all sites. Competition coefficients between individual species and the fish assemblage exceeded 1 for six of ten species indicating strong potential of competition for food. Simplified trophic basis of production and competition for depauperate food resources in regulated rivers potentially results in unstable food web structure and may partly explain erratic shifts in abundance or extirpation of native fishes.
Download or read book Native and Nonnative Fish Community and Food web Dynamics in Dryland Streams of the American Southwest written by Jane S. Rogosch and published by . This book was released on 2019 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshwater biodiversity is at once the most diverse and the most imperiled among the world's ecosystems. In the southwest, regional biodiversity and endemism face challenges imposed by declining water availability and widespread nonnative species proliferation. In this dissertation, I explore how these challenges affect fish community dynamics and native species persistence in dryland rivers, and explore the effectiveness of nonnative removal programs toward native fish conservation. The overarching questions motivating my research are: (1) How are fish communities responding to a changing climate? (2) How does flow intermittence and species origin shape freshwater fish beta diversity across dryland riverscapes? (3) Can we restore native species food-web dynamics through invasive species management? (4) Do strategic and opportunistic removal programs result in measurable, and if so comparable, benefits to native species conservation? Demographic models linking native and nonnative populations to flow dynamics predicted that contemporary declines in the frequency of peak flows, and increases in drought frequency are likely to result in nonnative dominant fish assemblages and diminished native fish populations. I found that intermittent and perennial streams play complementary roles in supporting fish beta diversity, and that contributions of intermittent streams to overall beta diversity were relatively consistent through time, primarily supporting a unique composition of native fishes. Although nonnative species control and removal programs are a common management strategy they have not always been successful. However, I found that nonnative removal efforts allowed native species to recover in their food-web dynamics, by returning to higher trophic levels and isotopic niches comparable to individuals that did not co-occur with nonnative fishes. In a model informed by long-term monitoring programs, I also found that both opportunistic and strategic removal strategies were predicted to decrease native fish extinction probabilities. These results were encouraging, and demonstrated that removal programs can meet recovery goals even over large areas and long after nonnative species are established.
Download or read book The Influence of Land Use and Mediterranean Seasonality on California Stream Fishes written by Kristina Yoshida and published by . This book was released on 2015 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshwaters ecosystems support extraordinary biodiversity relative to their extent and provide important societal benefits. As such, freshwater environments and biota are often heavily impacted by anthropogenic activities. Freshwater fishes in Mediterranean-climate regions are especially impacted because of large human populations in these regions and extensive agricultural production, extensive river modification for flood control and to meet societal demands, and because these systems are heavily invaded by non-native organisms. The distribution and ecology of freshwater fishes in Mediterranean-climate regions are also influenced by the distinct wet and dry periods and the high inter-annual variability in precipitation. Thus, efforts to manage and conserve native fishes in Mediterranean-climate regions require understanding both the effects of human disturbance and the strong seasonality that characterizes these regions. In this dissertation, I examine the relationship between land use and Mediterranean seasonality on freshwater fishes in streams within the greater San Francisco Bay region in California, USA. In my second chapter, I use a multivariate approach to explore variability among fish communities in 25 Bay Area watersheds. I found that a combination of local (water conductivity) and watershed-scale factors (percent forested watershed, watershed area, elevation) were important predictors of fish communities across sites. Furthermore, watershed-scale factors had indirect effects on fish communities through their influence on a local-scale factor, water conductivity. The results of this chapter highlight the importance of considering both the direct and indirect effects of watershed-scale factors on freshwater fish communities. In my third chapter, I continued my analysis of land use and fish communities with a focus on contemporary land change. For this chapter, I performed a resurvey study, surveying the habitat and fish communities in 32 sites in the Alameda Creek Watershed that had been surveyed by Dr. Robert Leidy in the mid-1990s, including sites in the rapidly urbanizing Livermore Valley region. Again using a multivariate approach, I found that the increase in urbanization across an approximately 16-year period was related to change in fish community composition, a decline in native species richness, and a decline in a common native cyprinid - changes that were not observed in another part of the watershed that has experienced little land use change in the last 16 years. The relationship between land use change and fish community change was strongest when considering land use change at a local scale. These results suggest that ongoing land change alters fish communities and that contemporary resurveys are an important tool for examining how freshwater taxa respond to recent and ongoing environmental change. In my final chapter, I assessed how seasonal drought, a characteristic feature of Mediterranean-climate systems, influenced food webs in a small intermittent stream in Marin County, CA that provides rearing habitat for threatened steelhead trout (Oncorhynchus mykiss). I used stable isotopes of carbon and nitrogen to characterize food web structure and the trophic position of a suite of predators in this system, including O. mykiss and several macroinvertebrate predators. I compared food web snapshots across time, as well as between permanent and temporary pools. I found that the intermittent stream food web remained relatively stable across time and did not differ between pool types. However, I also found significant changes in the trophic position, niche width, and mean [delta]13C values for aquatic predators. This study provides an important first look at the trophic ecology of an imperiled fish species in intermittent streams during the summer drought season, and emphasizes that food chain length increases across the drought season, possibly because invertebrate prey are concentrated with declining water levels. In conclusion, my research shows that anthropogenic factors at the watershed scale influence instream conditions and freshwater fish communities, and emphasizes that contemporary changes in land use can have subtle changes on fish community structure, which may be indicative of future declines of extirpations of native fishes. Finally, my research shows that changing conditions across the summer drought season lead to shifts in the trophic ecology of some, but not all, aquatic predators, including threatened steelhead trout. Overall my research contributes to a growing body of research that demonstrates how multi-scale natural and anthropogenic factors influence freshwater fishes in Mediterranean-climate region.
Download or read book The Impacts of Native and Nonnative Fish on Stream Communities written by Nicolaas W. Bouwes and published by . This book was released on 1999 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brown Trout written by Javier Lobón-Cerviá and published by John Wiley & Sons. This book was released on 2017-12-18 with total page 821 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brown Trout: Biology, Ecology and Management A comprehensive guide to the most current research, history, genetics and ecology of the brown trout including challenging environmental problems The brown trout is an iconic species across its natural European distribution and has been introduced throughout the World. Brown Trout offers a comprehensive review of the scientific information and current research on this major fish species. While the brown trout is the most sought species by anglers, its introduction to various waters around the world is causing serious environmental problems. At the same time, introduction of exogenous brown trout lineages threats conservation of native gene pools of populations in many regions. The authors summarize the important aspects of the brown trout’s life history and ecology and focus on the impact caused by the species. The text explores potential management strategies in order to maintain numerous damaged populations within its natural distributional range and to ameliorate its impacts in exotic environments. The authors include information on a wide-range of topics such as recent updates in population genetics, evolutionary history, reproductive traits and early ontogeny, life history plasticity in anadromous brown trout and life history of the adfluvial brown trout and much more. This vital resource: Contains the latest research on the biology and ecology of brown trout Includes information on phylogeography, genetics, population dynamics and stock management Spotlights the brown trout’s introduction to regions around the world and the serious environmental impacts Offers a comprehensive review of conservation and management techniques Written for salmonid scientists and researchers, fishery and environmental managers, and students of population genetics, ecology and population dynamics, Brown Trout explores the most recent findings on the history, ecology and sustainability of this much-researched species.
Download or read book Trout and Char of the World written by Jeffrey L. Kershner and published by . This book was released on 2019 with total page 831 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first comprehensive look at the taxonomy, life history, and conservation status of the world's trout and char. These are fascinating and beautiful fish that rate high for the angler as well as for tourist and recreational economies. Trout and char also play key roles in the ecology of many lake and river systems around the world. Trout and char are abundant in many regions, but most native species are on the decline. Some are classified as vulnerable, threatened, or endangered. Because of their widespread stocking in regions where they are not native, some trout and char also are the cause for threats to other native species. Loss of habitat, an expanding human population, and rapid climate change are challenging their future as streams warm and waters become more variable in their flows. This book examines trout and char from all these perspectives. Early chapters explore the unique diversity and life history aspects of trout and char and provide information on the taxonomy and systematics while also detailing some of unique life histories. New information is presented about species diversity and distributions by country. Summary chapters explore significant conservation and management challenges of broad interest to scientists, resource managers, anglers, and interested public. Trout and Char of the World end s with a series of essays exploring the future of trout and char over the next 50 years. Trout and Char of the World will be a primary resource for trout and char biologists, conservationists, and anglers in the many countries where trout and char are native or have been introduced, and a resource for anyone interested in learning more about the diversity and distribution of trout and char worldwide.--
Download or read book Biogeochemistry of Wetlands written by K. Ramesh Reddy and published by CRC Press. This book was released on 2022-09-10 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.
Download or read book Global Warming written by John T. Houghton and published by Cambridge University Press. This book was released on 1997-09-18 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: The best briefing on global warming the student or interested general reader could wish for.
