Multiple Stressors In River Ecosystems

Multiple Stressors in River Ecosystems: Status, Impacts and Prospects for the Future provides a comprehensive and current overview on the topic as written by leading river scientists who discuss the relevance of co-occurring stressors for river ecosystems. River ecosystems are subject to multiple stressors that threaten their ecological status and the ecosystem services they provide. This book updates the reader’s knowledge on the response and management of river ecosystems to multi-stress situations occurring under global change. Detailing the risk for biodiversity and functioning in a case-study approach, it provides insight into methodological issues, also including the socioeconomic implications. Presents a case study approach and geographic description on the relevance of multiple stressors on river ecosystems in different biomes Gives a uniquely integrated perspective on different stressors, including their interactions and joint effects, as opposed to the traditional one-by-one approach Compiles state-of-the-art methods and technologies in monitoring, modeling and analyzing river ecosystems under multiple stress conditions

There is a pressing need for developing and testing a general set of theories in order to provide a confident basis for prediction of multiple stressor effects. Confident prediction is central to confident decision making in water pollution control. Consequently, WERF commissioned this study which has as its goal to provide a study design based on good science that helps establish a general, conceptual approach to multiple stressors. The objectives of the study are to develop a flexible and scientifically defensible conceptual model of the environmental effects of multiple stressors on river and stream ecosystems; develop a study design to test the conceptual model of multiple stressor effects; and, document the process used to arrive at the conceptual model. The multiple stressor conceptual model includes two main components: (1) a diagram that portrays the main features of the study team's understanding of how multiple stressors would interact and the nature of the effects; and (2) a series of three testable risk hypotheses. These two components follow the guidance provided by the U.S. EPA for ecological risk assessment. The proposed conceptual model encompasses the following key assumptions: interactions between the stressor and the ecosystem are dependant upon the existing baseline conditions; for each stressor/baseline combination there will theoretically be a functional and a structural response; effects on habitat are caused by structural or functional responses to stressors; and effects on habitat can cause structural or functional responses.

This open access book surveys the frontier of scientific river research and provides examples to guide management towards a sustainable future of riverine ecosystems. Principal structures and functions of the biogeosphere of rivers are explained; key threats are identified, and effective solutions for restoration and mitigation are provided. Rivers are among the most threatened ecosystems of the world. They increasingly suffer from pollution, water abstraction, river channelisation and damming. Fundamental knowledge of ecosystem structure and function is necessary to understand how human acitivities interfere with natural processes and which interventions are feasible to rectify this. Modern water legislation strives for sustainable water resource management and protection of important habitats and species. However, decision makers would benefit from more profound understanding of ecosystem degradation processes and of innovative methodologies and tools for efficient mitigation and restoration. The book provides best-practice examples of sustainable river management from on-site studies, European-wide analyses and case studies from other parts of the world. This book will be of interest to researchers in the field of aquatic ecology, river system functioning, conservation and restoration, to postgraduate students, to institutions involved in water management, and to water related industries.

There is a pressing need for developing and testing a general set of theories in order to provide a confident basis for prediction of multiple stressor effects. Confident prediction is central to confident decision making in water pollution control. Consequently, WERF commissioned this study, which has as its goal to provide a study design based on good science that helps establish a general, conceptual approach to multiple stressors. The objectives addressed in this report are: (1) review and critique the existing body of knowledge for multiple stressors; (2) develop a searchable, annotated bibliography of multiple stressor research; and, (3) identify gaps in the body of knowledge. A rigorous, theoretical basis for the prediction of multiple stressor effects could not be developed from the literature on experimental studies of multiple stressor effects in aquatic ecosystems. Despite the wealth of observational data, the existence of several useful tools for interpretation of cause/effect relationships (including formal Stressor Identification methods), and the studies reviewed in this report, there are no tools that allow a confident, a priori, prediction of ecosystem response to multiple stressors. The current literature provides, at best, a series of site-specific glimpses of the response of ecological communities and ecosystems to multiple stressors. There is seldom, if ever, any reference to a more generalized model of multiple stressor effects apart from the discussion of the expectations regarding additivity versus synergism. Many articles that purport to be multiple stressor studies do not go beyond an inventory of the various stresses and upsets affecting the ecosystem, without attempting to assess the interactions among them.

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

Ecotoxiclogical risk from multiple stressors covers any situation where org- isms are exposed to a combination of environmental stressors. These include physical and chemical pollutants as well as other stressors such as parasites and environmental impact (e. g. , climate change or habitat loss). The combi- tion of stressors can result in increased risk to organisms (either additive or synergistic effects) or decreased effects (protective or antagonistic effects). The multiple stressor challenge is an international, multi-disciplinary problem requiring an international, multi-disciplinary approach. The c- rent approach to multiple stressors is to examine one stressor at a time and assume additivity. Little work has been done on combinations of stressors such that potential interactions can be determined. The problem is very complex. Multiple stressors pose a whole spectrum of challenges that range from basic science to regulation, policy and gove- ance. The challenges raise fundamental questions about our understanding of the basic biological response to stressors, as well as the implications of those uncertainties in environmental risk assessment and management. In addition to the great breadth, there is also great depth in the research ch- lenges, largely due to the complexity of the issues. From a basic science point of view, many of the mechanisms and processes under investigation are at the cutting edge of science — involving new paradigms such as genomic ins- bility and bystander effects.

This text examines the impact of climate change on freshwater ecosystems, past, present and future. It especially considers the interactions between climate change and other drivers of change including hydromorphological modification, nutrient loading, acid deposition and contamination by toxic substances using evidence from palaeolimnology, time-series analysis, space-for-time substitution, laboratory and field experiments and process modelling. The book evaluates these processes in relation to extreme events, seasonal changes in ecosystems, trends over decadal-scale time periods, mitigation strategies and ecosystem recovery. The book is also concerned with how aspects of hydrophysical, hydrochemical and ecological change can be used as early indicators of climate change in aquatic ecosystems and it addresses the implications of future climate change for freshwater ecosystem management at the catchment scale. This is an ideal book for the scientific research community, but is also accessible to Masters and senior undergraduate students.