5/25/2016  |   13:30 - 13:45   |  313

ECOLOGICAL IMPACTS OF ALTERED RIVER FLOW REGIMES The range and variation of stream and river flows over recent historical time, referred to as the natural flow regime, has acted as a template for contemporary ecological processes, adaptations and support of native biodiversity. Extensive construction of dams by humans for water supply, hydropower generation and flood mitigation has altered the natural dynamics of ecologically important flows and aquatic biodiversity at regional, continental and global scales. The deteriorating condition of riverine ecosystems and loss of freshwater biodiversity from dam impacts and flow modification has led to the field of environmental flows (e-flows), defined as ‘the quantity, quality and timing of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend on these ecosystems’. Recent developments in e-flows science, methods of assessment and implementation reveal important achievements, as well as limitations in eco-hydrological understanding and management practice. Climate change and novel alterations to river flow regimes and aquatic ecosystems will challenge the science and practice of environmental flows, and make freshwater ecosystem protection and restoration even more urgent as well as more complex.

Angela Arthington (Primary Presenter/Author), Australian Rivers Institute, Griffith University, a.arthington@griffith.edu.au;


Presentation:
This presentation has not yet been uploaded.

5/25/2016  |   13:45 - 14:00   |  313

FLOW MANAGEMENT FOR HYDROPOWER EXTIRPATES AQUATIC INSECTS, THE FOUNDATION OF RIVERINE FOOD WEBS Dams impound the majority of rivers and provide important societal benefits including daily water releases to provide on-peak hydroelectricity generation. Such “hydropeaking” is common worldwide, and governments are planning extensive new development of hydropower, yet the downstream impacts of hydropeaking remain unclear. We evaluated aquatic insect response to hydropeaking using a life history-hydrodynamic model. Our model predicts that aquatic insect abundance below hydropeaking dams will depend on a basic life history trait—egg laying behavior of adults—such that open-water layers will be unaffected, while ecologically important river-edge layers such as mayflies will be extirpated. These predictions are supported by a >2500 sample citizen science dataset of aquatic insects from the Colorado River in Grand Canyon, and by a survey of insect diversity and hydropeaking intensity across dammed rivers of the Western US. Our study demonstrates that river health is degraded below hydropeaking dams, with biodiversity loss comparable to rivers polluted by toxic chemicals. Our results also inform the design of cost-effective environmental flows that should mitigate the deleterious impacts of hydropeaking on aquatic insects, biodiversity, and ecosystem services.

Ted Kennedy (Primary Presenter/Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, tkennedy@usgs.gov;


Jeffrey Muehlbauer ( Co-Presenter/Co-Author), University of Alaska Fairbanks, USGS Alaska Cooperative Fish and Wildlife Research Unit, jdmuehlbauer@alaska.edu;


Charles Yackulic ( Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, cyackulic@usgs.gov;


Dave Lytle ( Co-Presenter/Co-Author), Oregon State University, lytleda@oregonstate.edu;


Scott Miller ( Co-Presenter/Co-Author), BLM/USU National Aquatic Monitoring Center, Department of Watershed Sciences, Utah State University, scott.miller@usu.edu;


Kimberly Dibble ( Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, kdibble@usgs.gov;


Eric Kortenhoeven ( Co-Presenter/Co-Author), USGS-Grand Canyon Monitoring and Research Center, ekortenhoeven@usgs.gov;


Anya Metcalfe ( Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, ametcalfe@usgs.gov;


Colden Baxter ( Co-Presenter/Co-Author), Idaho State University, baxtcold@isu.edu;


Presentation:
This presentation has not yet been uploaded.

5/25/2016  |   14:00 - 14:15   |  313

ADDRESSING THE ECOLOGICAL IMPACTS OF DAMS THROUGH DAM REMOVAL IN THE U.S. Dams alter flow, impair in-stream habitat, disconnect adjacent reaches, and negatively influence the transport and processing of sediment and organic material. While some dams in the United States play an important role in water supply, flood control, and irrigation, many no longer serve their original purpose, are poorly maintained, and are good candidates for removal. Dam removal is gaining momentum as a restoration tool. For dams that still provide a specific function, the benefits of the structure may no longer outweigh the impacts to fisheries and river habitat. American Rivers has documented the removal of more than 1,200 dams across the United States and maintains an interactive map of known projects. With limited resources and thousands of dams to prioritize for removal, information to guide the process is of principal importance. This talk will provide an overview of published dam removal science, review patterns of dam removal rates and geography over time, and acknowledge gaps in our collective understanding of the impact of dam removal on river ecosystems and identify research needs for advancing the practice of dam removal.

Erin Singer McCombs (Primary Presenter/Author), American Rivers, emccombs@americanrivers.org;


Laura S. Craig ( Co-Presenter/Co-Author), American Rivers, lcraig@americanrivers.org;


Brian Graber ( Co-Presenter/Co-Author), American Rivers, bgraber@americanrivers.org;


Serena McClain ( Co-Presenter/Co-Author), American Rivers, smcclain@americanrivers.org;


Presentation:
This presentation has not yet been uploaded.

5/25/2016  |   14:15 - 14:30   |  313

CULVERTS IN THE BOREAL FOREST: IMPACTS AND RESTORATION METHODS FOR NATIVE FRESHWATER FISHES In the boreal forest, industrial development has resulted in the installation of thousands of culverted road crossings that can degrade habitat and disrupt connectivity for freshwater fishes. Herein, we first describe the extent to which culverts are altering stream fish communities in the boreal forest by means of a comparative field study. We then describe the management utility of an optimization-analysis tool to prioritize problem culverts for restoration by incorporating region-specific parameter estimates of budgetary constraints, culvert (i.e. barrier) passibility, and species-specific life history information. Results from the field study suggest that in addition to effecting fish passage and stream connectivity, alterations to instream fish habitat from culverts may be driving large-scale changes in stream fish communities in the boreal forest, and warrants immediate management action. Optimization-model outputs indicate that for Arctic Grayling (Thymallus arcticus) and Bull Trout (Salvelinus confluentus), a large proportion (~61-83%) of isolated habitat can be reconnected with a low investment (~$200K to $500K). This study provides important evidence supporting the utility of this optimization-based method for prioritizing conservation efforts for freshwater fish in low-gradient forested watersheds.

Bryan Maitland (Primary Presenter/Author), University of Wyoming, bmaitlan@uwyo.edu;


Mark Poesch ( Co-Presenter/Co-Author), University of Alberta, poesch@ualberta.ca;


Axel Anderson ( Co-Presenter/Co-Author), Foothills Research Institute, University of Alberta, aeanders@ualberta.ca;


Presentation:
This presentation has not yet been uploaded.

5/25/2016  |   14:30 - 14:45   |  313

RIVER NAVIGATION INFRASTRUCTURE AND IMPACTS Overwhelmingly, rivers today serve multiple overlapping human purposes, including water supply, waste disposal, flood conveyance, recreation, power generation, etc. Increasingly, many rivers are "service limited," and human uses intersect and constrain each other as well as ecosystem services. River navigation impacts vary in magnitude from negligible (e.g., aboriginal river transport) to fluvial-industrial complexes that have dramatically altered the hydrology, form, and function of those rivers. In industrialized rivers, navigation occupies a large swath of "service space," often strongly constraining other human and environmental services. A review of river navigation worldwide suggests that the service burden imposed correlates foremost with the navigation depth imposed on a river relative to its natural or pre-regulation depth range. Other factors such as volume of shipping, vessel width, vessel types, etc. are of secondary importance. Depending on local river conditions and infrastructure toolkits, navigation constrains other river services through: altered hydrology, channel simplification and straightening, altered cross-sectional geometry, altered sediment dynamics, and cascading secondary impacts. As many developed regions begin river-service reconciliation, solutions are needed to address the disproportionate burden navigation often places on rivers.

Nicholas Pinter (Primary Presenter/Author), University of California at Davis, npinter@ucdavis.edu;


Presentation:
This presentation has not yet been uploaded.

5/25/2016  |   14:45 - 15:00   |  313

EXPLORING OPPORTUNITIES FOR ADDRESSING MULTIPLE THREATS IN FRESHWATER CONSERVATION Major challenges to understanding the nature of multiple stressor effects on individuals, populations, and communities in freshwater ecosystems remain. Research is needed to identify the prevalence, interaction and linkages between abiotic and biotic stressors, and to assess their effects on the ecological status of freshwater ecosystems in order to improve water management practice and policies. This presentation aims to explore and shed light on the links between different exposure stressors and modifiers confronting freshwater ecosystems now and in the future. Using a series of case studies and systematic review, I discuss the wide array of freshwaters affected by multiple stressors, the spatial and temporal scales involved, the species and ecosystem processes affected, and the resulting conservation challenges and emerging opportunities.

Julian Olden (Primary Presenter/Author), University of Washington, olden@uw.edu;


Presentation:
This presentation has not yet been uploaded.