Download or read book Seasonal and Longitudinal Investigation on the Impacts of Recreational Activities on the Aquatic Macroinvertebrate Community Within the San Marcos River written by Ovie Oluwanisola Agare and published by . This book was released on 2016 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the San Marcos River, recreational activities are most pronounced between April and October. Given the continued urbanization and increasing population in San Marcos there is need for a quantitative study on the possible effect of elevated recreational activities on the aquatic macroinvertebrates within the river. Furthermore, currently, there has been no study which quantified patterns in macroinvertebrate drift and benthic community structure simultaneously in the San Marcos River. Information on drift patterns and benthic macroinvertebrate habitat relationships is necessary to understand mechanisms for species persistence within the San Marcos River. In this study, I examined the seasonal and longitudinal patterns of benthic macroinvertebrate community composition at three different sites within the San Marcos River. I also examined the seasonal and longitudinal response of the drifting aquatic macroinvertebrates to changes in their habitat as a result of recreational activities in the San Marcos River. Tubing and swimming accounted for most of the recreation activity (>90%). Across all seasons, the upstream most study site had the highest drift densities compared to two downstream study sites. Canonical Correspondence Analysis (CCA) results explained 15.3% of the variability in the San Marcos River benthic macroinvertebrate community among vegetated habitats and 23.9% among open substrate habitats. Study results indicated that drift is related to benthic abundance. Macroinvertebrate drift densities followed the typical circadian pattern observed in other river systems and results indicated no increase in macroinvertebrate drift density during the peak recreation period. Conclusively, study results indicated that macroinvertebrates at the two upstream sites were not impacted by recreation and turbidity. However, the lower most study site, based on the CCA results indicate that substrate and turbidity are factors influencing the macroinvertebrate community.
Download or read book Seasonal and Longitudinal Changes in Functional Feeding Group Composition of Benthic Macroinvertebrates in the San Marcos River Texas written by Joseph McMurry Owen and published by . This book was released on 1996 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Influence of Light Availability on Metabolism in an Urban Spring fed River written by Matthew Stehle and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In aquatic ecosystems, temperature and light are the primary drivers of ecosystem metabolism, which is comprised of gross primary production (GPP) and ecosystem respiration (ER). However, light availability and temperature are generally seasonally synchronous in aquatic systems outside of the tropics, thus it is difficult to assess the independent influence of each parameter on ecosystem metabolism. I examined the effects of seasonal light availability on both GPP and ER, macrophyte community dynamics, and autotrophic metabolism in the San Marcos River, a physicochemically stable spring-fed system with high perennial macrophyte biomass. I estimated GPP, ER, and net ecosystem production (NEP) for spring, summer, and winter seasons in the upper San Marcos River. Using high-resolution drone imagery and in-field measurements, I determined seasonal biovolume (m3) across four reaches of varying recreational intensity. Finally, I used metabolic chambers to estimate seasonal GPP, respiration (R), and net primary production (NPP) of three macrophyte species and plastic plant analogues of increasing morphological complexity to determine how structural complexity influences metabolism of macrophytes and their epiphyte communities. I found that both GPP and ER in the upper San Marcos River were strongly correlated with seasonal light availability, indicating autotrophic respiration as a substantial portion of ER. I found that reach-scale macrophyte coverage and biovolume are largely controlled by recreational activity and not seasonal light availability. Finally, macrophyte and epiphyte metabolism were different across seasons and morphotypes, with the most structurally complex macrophytes exhibiting the greatest epiphyte metabolism. Overall, this study indicates that ecosystem metabolism in thermally stable spring-fed rivers is largely driven by light limitation of autotrophic biomass and that human recreational intensity influences ecosystem functioning.
Download or read book A Recreational Use Survey of the San Marcos River written by David D. Bradsby and published by . This book was released on 1994 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The San Marcos River written by Robert W. Spain and published by . This book was released on 1994 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book San Marcos River written by Texas A & M University. Department of Landscape Architecture and published by . This book was released on 1975 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detailed Project Report and Integrated Environmental Assessment San Marcos River Section 206 Aquatic Ecosystem Restoration Project written by United States. Army. Corps of Engineers and published by . This book was released on 2014 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental impacts on aquatic diversity written by Katie Siech and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluating the Impacts of Winter Drawdown on Macroinvertebrate Communities Within the Context of Localized Environmental Conditions written by Gabrielle Trottier and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The regulation and management of lake water levels have become a major form of anthropogenic disturbance in temperate and boreal aquatic ecosystems. Drawing the water level down as the winter season progresses can lead to substantial exposure of the littoral zone, rendering it susceptible to desiccation and freezing. Such changes in the hydrological regime of littoral zones can have significant effects on aquatic biota, including macroinvertebrates. These organisms are widely considered as robust bioindicators, but it is also well known that their abundance and distribution is characterized by substantial patchiness. Often, scientists who use macroinvertebrates as bioindicators, focus their sampling on a single habitat type (e.g., stony littoral) to reduce the heterogeneity in macroinvertebrate distributions. However, applying such an approach in the context of an environmental stressor makes it difficult to draw general conclusions about the impact of a potential stressor on the entire littoral zone. Recently, a debate has emerged in the literature over the effects of water level drawdown on macroinvertebrate communities and we think that at least part of this debate may be due to different sampling strategies employed across studies to examine the effects of drawdown on macroinvertebrate communities. In order to evaluate how nearshore macroinvertebrate communities, from a variety of habitats, are affected by drawdown, we sampled 15 reservoirs and quantified macroinvertebrate abundance and composition. To these data, we applied a combination of (generalized) linear mixed effects models and multivariate analyses to answer the following question; what are the effects of drawdown on macroinvertebrate abundance and community composition? To address this question and incorporate the possible effects of heterogeneity in abundance and distribution of macroinvertebrates, we explicitly considered multiple physical environmental variables as additional predictors of macroinvertebrate abundance and community composition. We found that drawdown and thermal regime were significant predictors of macroinvertebrate abundance, but explained negligible amounts of variation in the community composition. Overall, these findings help elucidate how macroinvertebrate communities respond to winter drawdown and strengthen the knowledge on how localized environmental conditions influence macroinvertebrates. Furthermore we think that our sampling and analytical approach provides a useful template for other scientists to adopt when quantifying the effect of a potential stressor on nearshore macroinvertebrate communities." --
Download or read book San Marcos River a reconnaissance study written by University of Texas at Austin. School of Architecture and published by . This book was released on 1972 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods in Stream Ecology written by F. Richard Hauer and published by Academic Press. This book was released on 2011-04-27 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods in Stream Ecology, Second Edition, provides a complete series of field and laboratory protocols in stream ecology that are ideal for teaching or conducting research. This updated edition reflects recent advances in the technology associated with ecological assessment of streams, including remote sensing. In addition, the relationship between stream flow and alluviation has been added, and a new chapter on riparian zones is also included. The book features exercises in each chapter; detailed instructions, illustrations, formulae, and data sheets for in-field research for students; and taxanomic keys to common stream invertebrates and algae. With a student-friendly price, this book is key for all students and researchers in stream and freshwater ecology, freshwater biology, marine ecology, and river ecology. This text is also supportive as a supplementary text for courses in watershed ecology/science, hydrology, fluvial geomorphology, and landscape ecology. Exercises in each chapter Detailed instructions, illustrations, formulae, and data sheets for in-field research for students Taxanomic keys to common stream invertebrates and algae Link from Chapter 22: FISH COMMUNITY COMPOSITION to an interactive program for assessing and modeling fish numbers
Download or read book An Introduction to the Aquatic Insects of North America written by Richard W. Merritt and published by Kendall Hunt. This book was released on 1996 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drought and Aquatic Ecosystems written by P. Sam Lake and published by John Wiley & Sons. This book was released on 2011-06-09 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Droughts are a major hazard to both natural and human-dominated environments and those, especially of long duration and high intensity, can be highly damaging and leave long-lasting effects. This book describes the climatic conditions that give rise to droughts, and their various forms and chief attributes. Past droughts are described including those that had severe impacts on human societies. As a disturbance, droughts can be thought of as “ramps” in that they usually build slowly and take time to become evident. As precipitation is reduced, flows from catchments into aquatic systems decline. As water declines in water bodies, ecological processes are changed and the biota can be drastically reduced, though species and populations may survive by using refuges. Recovery from drought varies in both rates and in degrees of completeness and may be a function of both refuge availability and connectivity. For the first time, this book reviews the available rather scattered literature on the impacts of drought on the flora, fauna and ecological processes of aquatic ecosystems ranging from small ponds to lakes and from streams to estuaries. The effects of drought on the biota of standing waters and flowing waters and of temporary waters and perennial systems are described and compared. In addition, the ways in which human activity can exacerbate droughts are outlined. In many parts of the world especially in the mid latitudes, global warming may result in increases in the duration and intensity of droughts. Drought and Aquatic Ecosystems is essential reading for freshwater ecologists, water resource managers and advanced students.
Download or read book Ecological Effects of Water level Fluctuations in Lakes written by Karl M. Wantzen and published by Springer Science & Business Media. This book was released on 2009-05-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most aquatic ecosystems have variable water levels. These water-level fluctuations (WLF) have multiple effects on the organisms above and below the waterline. Natural WLF patterns in lakes guarantee both productivity and biodiversity, while untimely floods and droughts may have negative effects. Human impacts on WLF have led to a stabilization of the water levels of many lakes by hydraulic regulation, untimely drawdown due to water use, or floods due to water release from hydropower plants in the catchments. This book provides a first review in this field. It presents selected papers on the ecological effects of WLF in lakes, resulting from a workshop at the University of Konstanz in winter 2005. Issues addressed here include the extent of WLF, and analyses of their effects on different groups of biota from microorganisms to vertebrates. Applied issues include recommendations for the hydrological management of regulated lakes to reduce negative impacts, and a conceptual framework is delivered by an extension of the floodpulse concept for lakes. Current impacts on water use, including increasing demands on drinking and irrigation water, hydropower etc., and climate change effects on WLF make this book an essential resource for aquatic ecologists, engineers, and decision-makers dealing with the management of lake ecosystems and their catchments.
Download or read book Methods in Stream Ecology written by F. Richard Hauer and published by Academic Press. This book was released on 2017-01-16 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods in Stream Ecology provides a complete series of field and laboratory protocols in stream ecology that are ideal for teaching or conducting research. This two part new edition is updated to reflect recent advances in the technology associated with ecological assessment of streams, including remote sensing. Volume focusses on ecosystem structure with in-depth sections on Physical Processes, Material Storage and Transport and Stream Biota. With a student-friendly price, this Third Edition is key for all students and researchers in stream and freshwater ecology, freshwater biology, marine ecology, and river ecology. This text is also supportive as a supplementary text for courses in watershed ecology/science, hydrology, fluvial geomorphology, and landscape ecology. Methods in Stream Ecology, 3rd Edition, Volume 2: Ecosystem Structure, is also available now! Provides a variety of exercises in each chapter Includes detailed instructions, illustrations, formulae, and data sheets for in-field research for students Presents taxonomic keys to common stream invertebrates and algae Includes website with tables and a link from Chapter 22: FISH COMMUNITY COMPOSITION to an interactive program for assessing and modeling fish numbers Written by leading experts in stream ecology
Download or read book Eutrophication causes consequences and control written by Abid A. Ansari and published by Springer Science & Business Media. This book was released on 2010-10-17 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eutrophication continues to be a major global challenge to water quality scientists. The global demand on water resources due to population increases, economic development, and emerging energy development schemes has created new environmental challenges to global sustainability. Eutrophication, causes, consequences, and control provides a current account of many important aspects of the processes of natural and accelerated eutrophication in major aquatic ecosystems around the world. The connections between accelerated eutrophication and climate change, chemical contamination of surface waters, and major environmental and ecological impacts on aquatic ecosystems are discussed. Water quality changes typical of eutrophication events in major climate zones including temperate, tropical, subtropical, and arid regions are included along with current approaches to treat and control increased eutrophication around the world. The book provides many useful new insights to address the challenges of global increases in eutrophication and the increasing threats to biodiversity and water quality.
Download or read book Groundwater Surface Water Interactions written by Habil. Jörg Lewandowski and published by MDPI. This book was released on 2020-12-10 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent years have seen a paradigm shift in our understanding of groundwater–surface water interactions: surface water and aquifers were long considered discrete, separate entities; they are now understood as integral components of a surface–subsurface continuum. This book provides an overview of current research advances and innovative approaches in groundwater–surface water interactions. The 20 research articles and 1 communication cover a wide range of thematic scopes, scales, and experimental and modelling methods across different disciplines (hydrology, aquatic ecology, biogeochemistry, and environmental pollution). The book identifies current knowledge gaps and reveals the challenges in establishing standardized measurement, observation, and assessment approaches. It includes current hot topcis with environmental and societal relevance such as eutrophication, retention of legacy, and emerging pollutants (e.g., pharmaceuticals and microplastics), urban water interfaces, and climate change impacts. The book demonstrates the relevance of processes at groundwater–surface water interfaces for (1) regional water balances and (2) quality and quantity of drinking water resources. As such, this book represents the long-awaited transfer of the above-mentioned paradigm shift in understanding of groundwater–surface water interactions from science to practice.
