Summary
1. In an effort to develop quantitative relationships between various kinds of flow alteration and ecological responses, we reviewed 165 papers published over the last four decades, with a focus on more recent papers. Our aim was to determine if general relationships could be drawn from disparate case studies in the literature that might inform environmental flows science and management.

2. For all 165 papers we characterised flow alteration in terms of magnitude, frequency, duration, timing and rate of change as reported by the individual studies. Ecological responses were characterised according to taxonomic identity (macroinvertebrates, fish, riparian vegetation) and type of response (abundance, diversity, demographic parameters). A ‘qualitative’ or narrative summary of the reported results strongly corroborated previous, less comprehensive, reviews by documenting strong and variable ecological responses to all types of flow alteration. Of the 165 papers, 152 (92%) reported decreased values for recorded ecological metrics in response to a variety of types of flow alteration, whereas 21 papers (13%) reported increased values.

3. Fifty-five papers had information suitable for quantitative analysis of ecological response to flow alteration. Seventy per cent of these papers reported on alteration in flow magnitude, yielding a total of 65 data points suitable for analysis. The quantitative analysis provided some insight into the relative sensitivities of different ecological groups to alteration in flow magnitudes, but robust statistical relationships were not supported. Macroinvertebrates showed mixed responses to changes in flow magnitude, with abundance and diversity both increasing and decreasing in response to elevated flows and to reduced flows. Fish abundance, diversity and demographic rates consistently declined in response to both elevated and reduced flow magnitude. Riparian vegetation metrics both increased and decreased in response to reduced peak flows, with increases reflecting mostly enhanced non-woody vegetative cover or encroachment into the stream channel.

4. Our analyses do not support the use of the existing global literature to develop general, transferable quantitative relationships between flow alteration and ecological response; however, they do support the inference that flow alteration is associated with ecological change and that the risk of ecological change increases with increasing magnitude of flow alteration.

5. New sampling programs and analyses that target sites across well-defined gradients of flow alteration are needed to quantify ecological response and develop robust and general flow alteration–ecological response relationships. Similarly, the collection of pre- and post-alteration data for new water development programs would significantly add to our basic understanding of ecological responses to flow alteration.

https://www.waterboards.ca.gov/waterrights/water_issues/programs/bay_delta/deltaflow/docs/exhibits/swrcb/swrcb_poff2010_2.pdf

Ecological responses to altered flow regimes: a literature review to inform the science and management of environmental flows

R and streams, by their very nature long ribbons of aquatic habitat, are inherently difficult to study. Approaching the banks of a flowing-water (lotic) system, one can see only a short fragment of the entire stream, from one bend to another, and can gain little appreciation for important features that lie beyond view. Moreover, materials transported downstream by the flow, and organisms traveling up or down the hydraulic highway, are soon gone from the reach and the opportunity to study them is often lost. Lakes present their own challenges for study, but by contrast to streams, one can usually see large expanses from shore that encompass all major habitats needed for aquatic organisms to complete their life history, such as gravel shoals, beds of aquatic vegetation, and open water habitats. Much of our knowledge of the ecology of rivers and streams is based on observations and experiments on organisms and habitat in the short fragments we can view or quickly traverse on foot, and this limited understanding underpins our efforts at conservation of stream fishes. Here, we argue that this understanding is incomplete, like viewing only disjunct parts of a landscape painting through small holes in a curtain draping it. We propose that a continuous view of rivers is essential for effective research and conservation of their fishes and other aquatic biota—a view not just of disjunct reaches but of the entire spatially heterogeneous scene of the river environment, the riverscape, unfolding through time. One symptom of our incomplete understanding is the alarming rate of decline over the last 50 years of fishes that inhabit rivers and streams of North America. The public is aware that salmon are disappearing from the Pacific Northwest, with about a quarter of the 214 stocks of anadromous salmon and trout imperiled a decade ago (Nehlsen et al. 1991). Even little-known small fishes native to Great Plains and southwestern desert streams have suffered drastic declines (Minckley and Douglas 1991, Fausch and Bestgen 1997), and many are now either protected by federal or state listing as endangered or threatened species or are being considered for such protection. North America harbored the greatest diversity worldwide of temperate freshwater fishes (Warren and Burr 1994), crayfishes (Taylor et al. 1996), and mussels (Williams et al. 1993), but about 30% to 75% of the taxa in each group are at increased risk of extinction (i.e., categorized as rare, threatened, or endangered species). Fishes are also the most imperiled vertebrates worldwide (Allan and Flecker 1993, Leidy and Moyle 1998) and a large proportion spend at least part of their lives in streams.

https://www.jstor.org/stable/10.1641/0006-3568(2002)052%5B0483%3ALTRBTG%5D2.0.CO%3B2

Landscapes to Riverscapes: Bridging the Gap between Research and Conservation of Stream Fishes

Recognition of the escalating hydrological alteration of rivers on a global scale and resultant environmental degradation, has led to the establishment of the science of environmental flow assessment whereby the quantity and quality of water required for ecosystem conservation and resource protection are determined.

A global review of the present status of environmental flow methodologies revealed the existence of some 207 individual methodologies, recorded for 44 countries within six world regions. These could be differentiated into hydrological, hydraulic rating, habitat simulation and holistic methodologies, with a further two categories representing combination-type and other approaches.

Although historically, the United States has been at the forefront of the development and application of methodologies for prescribing environmental flows, using 37% of the global pool of techniques, parallel initiatives in other parts of the world have increasingly provided the impetus for significant advances in the field.

Application of methodologies is typically at two or more levels. (1) Reconnaissance-level initiatives relying on hydrological methodologies are the largest group (30% of the global total), applied in all world regions. Commonly, a modified Tennant method or arbitrary low flow indices is adopted, but efforts to enhance the ecological relevance and transferability of techniques across different regions and river types are underway. (2) At more comprehensive scales of assessment, two avenues of application of methodologies exist. In developed countries of the northern hemisphere, particularly, the instream flow incremental methodology (IFIM) or other similarly structured approaches are used. As a group, these methodologies are the second most widely applied worldwide, with emphasis on complex, hydrodynamic habitat modelling. The establishment of holistic methodologies as 8% of the global total within a decade, marks an alternative route by which environmental flow assessment has advanced. Such methodologies, several of which are scenario-based, address the flow requirements of the entire riverine ecosystem, based on explicit links between changes in flow regime and the consequences for the biophysical environment. Recent advancements include the consideration of ecosystem-dependent livelihoods and a benchmarking process suitable for evaluating alternative water resource developments at basin scale, in relatively poorly known systems. Although centred in Australia and South Africa, holistic methodologies have stimulated considerable interest elsewhere. They may be especially appropriate in developing world regions, where environmental flow research is in its infancy and water allocations for ecosystems must, for the time being at least, be based on scant data, best professional judgement and risk assessment. Copyright © 2003 John Wiley & Sons, Ltd.

http://www.swrcb.ca.gov/waterrights/water_issues/programs/bay_delta/deltaflow/docs/exhibits/swrcb/swrcb_tharme2003.pdf

A global perspective on environmental flow assessment: emerging trends in the development and application of environmental flow methodologies for rivers

SUMMARY 1. The flow regime is a primary determinant of the structure and function of aquatic and riparian ecosystems for streams and rivers. Hydrologic alteration has impaired riverine ecosystems on a global scale, and the pace and intensity of human development greatly exceeds the ability of scientists to assess the effects on a river-by-river basis. Current scientific understanding of hydrologic controls on riverine ecosystems and experience gained from individual river studies support development of environmental flow standards at the regional scale. 2. This paper presents a consensus view from a group of international scientists on a new framework for assessing environmental flow needs for many streams and rivers simultaneously to foster development and implementation of environmental flow standards at the regional scale. This framework, the ecological limits of hydrologic alteration (ELOHA), is a synthesis of a number of existing hydrologic techniques and environmental flow methods that are currently being used to various degrees and that can support comprehensive regional flow management. The flexible approach allows

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The ecological limits of hydrologic alteration (ELOHA): a new framework for developing regional environmental flow standards

SUMMARY 1. Natural biogeochemical processes and diverse communities of aquatic biota regulate freshwater quantity and quality in ways that are not sufficiently acknowledged nor appreciated by the water resources management community. The establishment and enforcement of environmental flow requirements offer promising means to improve and care for these critical environmental services. This Special Issue provides new insights and novel techniques to determine, protect and restore ecologically and socially sustainable flow regimes, and thereby help achieve the water-related goals of the Millennium Ecosystem Assessment. 2. Whilst alteration of flow, sediment, organic matter and thermal regimes interact to reduce biological diversity and the ecological integrity of freshwater ecosystems – and thereby degrade the properties and ecological services most valued by humans – ‘environmental flows’ left in rivers, or restored to developed rivers, will sustain many ecological and societal values. The success of river protection and rehabilitation ⁄ restoration depends upon understanding and accurately modelling relationships between hydrological patterns, fluvial disturbance and ecological responses in rivers and floodplains. 3. This Special Issue presents new analytical and modelling approaches to support the development of hydro-ecological models and environmental flow standards at multiple spatial scales – applicable to all rivers in any economic and societal setting. Examples include the new framework Ecological Limits of Hydrologic Alteration (ELOHA) founded on hydrological classification and gradient analysis; ecological trait analysis; Bayesian hierarchical modelling; Bayesian Decision Networks; and Integrated Basin Flow Assessment (IBFA). 4. Advances in the allocation of flood flows along the River Murray in Australia, an Ecosystems Function Model (HEC-EFM) for the Bill Williams River restoration programme in Arizona (U.S.A), the European Water Framework Directive, and improved management of hydroelectric dams demonstrate the potential for significant ecological recovery following partial restoration of natural river flow regimes. 5. Based on contributions to this Special Issue, the action agenda of the 2007 Brisbane Declaration on environmental flows and the wider literature, we propose an invigorated global research programme to construct and calibrate hydro-ecological

/pdf/preserving-the-biodiversity-and-ecological-services-of-454rvugm1g.pdf

Preserving the biodiversity and ecological services of rivers: new challenges and research opportunities

: This document is intended to update the concepts and ideas first presented in Information Paper 12, the first attempt to describe the Instream Flow Incremental Methodology in its entirety in 1982. This also is to serve as a comprehensive introductory textbook on IFIM for training courses as it contains the most complete and comprehensive description of IFIM in existence today. This should also serve as an official guide to IFIM in publication to counteract the misconceptions about the methodology that have pervaded the professional literature since the mid-1980's as this describes IFIM as it is envisioned by its developers The document is aimed at the decisionmakers of management and allocation of natural resources in providing them an overview; and to those who design and implement studies to inform the decisionmakers. There should be enough background on model concepts, data requirements, calibration techniques, and quality assurance to help the technical user design and implement a cost-effective application of IFIM that will provide policy-relevant information. Some of the chapters deal with basic organization of IFIM, procedural sequence of applying IFIM starting with problem identification, study planning and implementation, and problem resolution.

Stream habitat analysis using the instream flow incremental methodology

The conclusions of numerous stream restoration assessments all around the world are extremely clear and convergent: there has been insufficient appropriate monitoring to improve general knowledge and expertise. In the specialized field of instream flow alterations, we consider that there are several opportunities comparable to full-size experiments. Hundreds of water management decisions related to instream flow releases have been made by government agencies, native peoples, and non-governmental organizations around the world. These decisions are based on different methods and assumptions and many flow regimes have been adopted by formal or informal rules and regulations. Although, there have been significant advances in analytical capabilities, there has been very little validation monitoring of actual outcomes or research related to the response of aquatic dependent species to new flow regimes. In order to be able to detect these kinds of responses and to better guide decision, a general design template is proposed. The main steps of this template are described and discussed, in terms of objectives, hypotheses, variables, time scale, data management, and information, in the spirit of adaptive management. The adoption of such a framework is not always easy, due to differing interests of actors for the results, regarding the duration of monitoring, nature of funding and differential timetables between facilities managers and technicians. Nevertheless, implementation of such a framework could help researchers and practitioners to coordinate and federate their efforts to improve the general knowledge of the links between the habitat dynamics and biological aquatic responses.

/pdf/detecting-biological-responses-to-flow-management-missed-37pgdhk4ta.pdf

Detecting biological responses to flow management: Missed opportunities; future directions

/pdf/public-attitudes-and-knowledge-of-the-black-tailed-prairie-55fuhw5vf7.pdf

Public Attitudes and Knowledge of the Black-tailed Prairie Dog: A Common and Controversial Species

Black-tailed prairie dogs (Cynomys ludovicianus) historically occupied an 11-state region of the United States. We surveyed 1,900 residents (response rate 56%) of this region to understand citizen knowledge and perceptions about prairie dogs and their management. Those who have direct experience—e.g., those who live very close to prairie dog colonies or know the location of the nearest colony—have higher levels of knowledge. A significantly higher level of knowledge was documented among those who were politically active when compared with the general public. Those who found environmental issues difficult to understand were associated with lower knowledge. People with direct experience were likely to hold negative views, whereas those holding environmentalist values were likely to express positive attitudes toward the species. Although those with higher education reported more knowledge, there was no link between a person’s level of knowledge and perceptions of prairie dog management.

/pdf/public-knowledge-and-perceptions-of-black-tailed-prairie-10tm118r83.pdf

Public Knowledge and Perceptions of Black-Tailed Prairie Dogs

We studied six interagency negotiations covering Federal Energy Regulatory Commission (FERC) hydroelectric power licenses Negotiations occurred between state andfederal resource agencies and developers over project operations and natural resource mitigation We postulated that a balance of power among parties was necessary for successful negotiations We found a complex relationship between balanced power and success and conclude that a balance of power was associated with success in these negotiations Power played a dynamic role in the bargaining and illuminates important considerations for regulatory design

Berton Lee Lamb

Papers

Stream habitat analysis using the instream flow incremental methodology

Detecting biological responses to flow management: Missed opportunities; future directions

Public Attitudes and Knowledge of the Black-tailed Prairie Dog: A Common and Controversial Species

Public Knowledge and Perceptions of Black-Tailed Prairie Dogs

Power Distribution in Complex Environmental Negotiations: Does Balance Matter?