A Review Of The Impacts Of Climate Change On Bcs Freshwater Fish Resources And Possible Management Responses

As we approach the end of the twentieth century, public and scientific attention is focusing increasingly on the detection and assessment of changes in our environment. This unique volume addresses the potential implications of global warming for fisheries and the societies which depend on them. Using a 'forecasting by analogy' approach, which draws upon experiences from the recent past in coping with regional fluctuations in the abundance or availability of living marine resources, it is shown how we might be able to assess our ability to respond to the consequences of future environmental changes induced by a potential global warming. The book takes the form of a series of integrated case studies from around the globe, which are presented by an interdisciplinary group of leading researchers. This important and thought-provoking volume will be of interest to a wide range of scientists working in the fields of biology, marine and environmental science, climatology, economics and anthropology, as well as resource managers and policy makers concerned with the health and future of living marine resources.

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.

Global warming and climate change are growing environmental concerns which are much in the scientific, governmental and public eye. The potential impact on freshwater and marine fishes is immense, because most fish have no physiological ability to regulate their body temperature. This volume focuses on the effects of temperature at all levels of organization in fish, with particular emphasis on physiological function: cells, epithelia, organ systems, the whole organism, reproduction, behaviour, pollutant interactions, ecology and population dynamics, with each chapter written by experts in the field. Many chapters also speculate on the long-term physiological and ecological implications to fish of a 2-4°C global warming scenario. Researchers and graduate students in the areas of animal physiology and behaviour, environmental toxicology, population ecology and fisheries biology and management will find this volume of particular interest.

This report indicates that climate change will significantly affect the availability and trade of fish products, especially for those countries most dependent on the sector, and calls for effective adaptation and mitigation actions encompassing food production.

Species distribution models are useful tools that can be used to evaluate tradeoffs of management and conservation strategies under scenarios of environmental change. Modeling efforts for fish species have largely focused on cold-water, commercial, and recreationally-valued species, even though warm-water, non-game species have important roles in ecosystem services and processes. I developed species distribution models for fourteen warm-water fish species native to the Central United States and evaluated environmental drivers and predictive performance. I used an ensemble model approach produced by combining forecasts of five single-model techniques. Response plots and variable importance calculations were used to evaluate the influence of individual variables. The predictive performance of the ensemble models was assessed using area under the curve (AUC) of the receiver-operating characteristic plot. Ensemble model AUC values generally performed better than single-model types, suggesting ensemble models are more reliable and applicable for management purposes than single-models. Most models were influenced by a mix of climate, land use and geophysical variables; however, climate variables were the dominant environmental drivers across models. Next, I projected distribution responses of 14 warm-water fish species to climate and land use scenarios using the ensemble models combined with scenario analyses. I incorporated different time periods, greenhouse gas emissions scenarios, and general circulation models into the scenario analysis. I then tested the effect of climate change scenario and the incorporation of land use on range change. Although it has been hypothesized that warm-water fishes will generally benefit from future climate changes through range expansion, I found wide variability in range change across the species modeled. There was a significant effect of greenhouse gas scenario and year on overall range change for half of the species modeled. The incorporation of future land use projections into scenarios generally led to increased range expansion. I combined all scenarios into consensus projections to visualize range change projections across all scenarios. Some species expanded their range to the north and into higher elevations while other species were projected to lose significant portions of their range. For example, orangethroat darter ( Etheostoma spectabile ) is projected to gain between 30 to 90 percent new range and lose between 0 to 6 percent of its current range while bigmouth shiner (Hybopsis dorsalis ) is projected to gain between 0 to 20 percent new range and lose 75 to 100 percent of its current range. Variability in climate change responses across warm-water species may be a result of ecological traits, such as range size and fecundity. The variability in warm-water species' responses suggests management of these species can be informed through the use of species distribution modeling and scenario analysis.

Climate change not only involves rising temperatures but it can also alter the hydro-meteorological parameters of a region and the corresponding changes emerging in the various biotic or abiotic environmental features. One of the results of climate change has been the impact on the sediment yield and its transport. These changes have implications for various other environmental components, particularly soils, water bodies, water quality, land productivity, sedimentation processes, glacier dynamics, and risk management strategies to name a few. This volume provides an overview of the fundamental processes and impacts of climate change on river basin management and examines issues related to soil erosion, sedimentation, and contaminants, as well as rainfall-runoff modeling and flood mitigation strategies. It also includes coverage of climate change fundamentals as well as chapters on related global treaties and policies.

Climate change is a global issue and the effects on fish populations remain largely unknown. It is thought that climate change could affect fish at all levels of biological organisation, from cellular, individual, population and community. This thesis has taken a holistic approach to examine the ways in which climate change could affect fish from both tropical, marine ecosystems (Great Barrier Reef, Australia) and temperate, freshwater ecosystems (non-tidal River Thames, Britain). Aerobic scope of coral reef fish tested on the Great Barrier Reef was significantly reduced by just a 2°C rise in water temperature (31, 32 and 33°C, compared to the current summer mean of 29°C) due to increased resting oxygen consumption and an inability to increase the maximal oxygen uptake. A 0.3 unit decline in pH, representative of ocean acidification, caused the same percentage loss in aerobic scope as did a 3°C warming. Interfamilial differences in ability to cope aerobically with warming waters will likely lead to changes in the community structure on coral reefs with damselfish replacing cardinalfish. Concerning Britain, there is evidence of gradual warming and increased rainfall in winter months over a 150 year period, suggesting that British fish are already experiencing climate change. It was evident from an analysis of a 15 year dataset on fish populations in the River Thames, that cyprinid species displayed a different pattern in biomass and density to all the non-cyprinid fish population, suggesting that there will be interfamilial differences in responses to climate change. Using a Biological Indicator Approach on the three-spined stickleback, Gasterosteus aculeatus, a 2°C rise in water temperature resulted in a stress response at the cellular and whole organism level. A 6°C rise in temperature resulted in a stress response at the biochemical level (higher cortisol and glucose concentrations), cellular level (higher neutrophil: lymphocyte ratio) and whole organism level (higher ventilation rate and lowered condition factor, hepatosomatic index and growth). G. aculeatus is considered to be temperature tolerant; therefore these results indicate that climate change may prove to be stressful for more temperature-sensitive species. This study has demonstrated that climate change will have direct effects on fish populations, whether they are in temperate regions such as Britain or in tropical coral reefs, but with strong interfamilial differences in those responses.

Report of the Climate Variability, Climate Change and Fisheries Project -- Executive summary and general findings of the Climate Variability, Climate Change and Fisheries Project.