Sarah Yarnell, Ph.D., Associate Professional Researcher at the Center for Watershed Sciences, University of California – Davis

Sarah is an Associate Professional Researcher at the Center for Watershed Sciences.  Her studies focus on integrating the traditional fields of hydrology, ecology and geomorphology in the river environment.  She is currently conducting research that applies understanding of river ecosystem processes to managed systems in the Sierra Nevada, with a focus on the development and maintenance of riverine habitat.  She is a recognized expert in the ecology of the Foothill yellow-legged frog (Rana boylii), a California species of special concern that is listed as threatened in some regions, and she was the first researcher to apply sediment transport and two-dimensional hydrodynamic modeling techniques to the evaluation of instream amphibian habitat.

Her experience includes consultation as a technical expert for various hydroelectric power relicensing projects, where she has worked closely with government resource agencies and the private sector to assess the impacts of environmental flows on aquatic biota and provide recommendations for developing flows that improve the functioning of river ecosystems.  She is currently working with colleagues to apply a Functional Flows approach to the development of environmental flow criteria throughout the state.  In recent years, her research experience has expanded to include evaluation and restoration of headwater systems, particularly montane meadows in the Sierra Nevada and Cascade ranges.  Throughout her time at CWS, she has co-taught field-based river courses, such as Ecogeomorphology, and she teaches as a part-time lecturer for the Department of Earth & Planetary Sciences.  She is a member of the Hydrologic Sciences Graduate Group and finds working with students to be one of the highlights of her job.

2024 Science Symposium Presentation

Adaptively Managing a Functional Flow regime in California.

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Sarah Yarnell, Ph.D., Associate Professional Researcher at the Center for Watershed Sciences, University of California – Davis gives her presentation titled, “Adaptively Managing a Functional Flow regime in California.“

Baruch, E., S. Yarnell, T. Grantham, J. Ayers, A. Rypel, R. Lusardi, Mimicking functional elements of the natural flow regime promotes native fish recovery in a regulated river. Ecological Society of America. 14 July 2024.

Daniele Tonina, Ph.D., P.E., Professor Department of Civil & Environmental Engineering, University of Idaho | Co-Director, Center for Ecohydraulics Research | Science Advisory Board Member

Daniele Tonina joined the Center of Ecohydraulics Research and the Department of Civil & Environmental Engineering in 2009. Natural environments are complex systems that require a holistic approach for synthesizing physical and biological processes. He follows this approach in his research, which can be broadly defined as ecohydrology. His research interests are in identifying and modeling linkages between physical processes and biological systems. This line of research improves our knowledge and ability to manage and protect river basins, water supplies, and riverine ecosystems, and thus forms an important basis for new public policy, urban development, and engineering designs. His research is not focused on one subject, but it examines the connection and interaction of different components that form a natural system.

His interests include surface and ground water processes and the interface between these two major systems — the hyporheic zone. In subsurface hydrology, he has investigated solute transport in heterogeneous formations with a stochastic approach. In surface waters, he is interested in sediment transport, river morphology response to disturbances and their effect on solute mixing and the aquatic habitat. He is particularly interested in surface-subsurface water interaction and its implications for ecosystems and water quality. He has been investigating how these interactions affect nutrient cycles, in-stream self-cleaning processes, both of which address engineering needs and answer ecological questions on how to manage and protect water resources. He is interested in defining the importance of hyporheic flow in different environments and under changing conditions. He is currently collaborating on the evaluation of a new airborne green lidar technology for surveying both terrestrial and aquatic systems (EAARL systems). This tool will provide extremely accurate topographic data of river networks and their surrounding riparian and floodplain zones and will support new research in river network evolution and structure, aquatic and terrestrial habitats, and surface processes.

2024 Science Symposium Presentation

Nitrification/denitrification, temperature and dissolved Oxygen changes within the hyporheic zone and emissions of greenhouse gases.

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Daniele Tonina, Ph.D., P.E., gives his presentation titled, Nitrification/denitrification, temperature and dissolved Oxygen changes within the hyporheic zone and emissions of greenhouse gases.

John Buffington, Ph.D., Research Geomorphologist, U.S. Forest Service

John Buffington is a Research Geomorphologist with the U.S. Forest Service, Rocky Mountain Research Station in Boise, Idaho.  He graduated from the University of California Berkeley in 1988 with a B.A. in geology and from the University of Washington in 1995 and 1998 with M.S. and Ph.D. degrees in geomorphology. 

He was a National Research Council Scholar from 1998-2000, a professor in the Center for Ecohydraulics Research at the University of Idaho from 2000-2004, editor of the Journal of Geophysical Research: Earth Surface from 2015-2018 and has been an editorial board member of Hydrological Processes since 2015.  His research focuses on fluvial and hillslope geomorphology of mountain basins, biophysical interactions, and the effects of natural and anthropogenic disturbances on aquatic habitat.  He has been a member of the Program’s Science Advisory Board since 2010.  

2024 Science Symposium Presentation

Stability of channel morphology and aquatic habitat in a changing climate: Implications for management of regulated rivers.

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as John Buffington, Ph.D., Research Geomorphologist, U.S. Forest Service gives his presentation titled, “Stability of channel morphology and aquatic habitat in a changing climate: Implications for management of regulated rivers.”

Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program

Todd works on flow and sediment issues on the Trinity River for the TRRP and is currently investigating flow effects on temperature stratification in river pools, development of an acoustic technique for bedload monitoring, and evolution of Rush and Indian creek deltas and their capacity for rearing juvenile Chinook salmon. Todd completed a four-year enlistment in the U.S. Coast Guard before starting his career in river and salmon restoration in 1994. His work has mainly focused on interties between sediment transport dynamics, streamflow, and biological populations in rivers in the Western U.S., Alaska, New York, and Costa Rica.

Todd has earned a B.S. in Watershed analyses and restoration and an M.S. in Watershed Management from Humboldt State University and a Ph.D. in Water Resources from the University of Idaho. His academic research included developing and testing an equation that predicts entrainment of waterlogged wood in rivers, streambed packing effects on sediment mobility, relative stability of salmon redds and ambient streambed areas, and salmon spawning effects on hyporheic (groundwater) flow and marine nutrients from salmon in streams. Todd’s free time is preferably spent building wood structures of any kind and caring for the land where he lives along Browns Creek.

2024 Science Symposium Presentation

History of fine sediment and its impacts on physical processes and biologic populations in the Trinity River.

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program gives his presentation titled, “History of fine sediment and its impacts on physical processes and biologic populations in the Trinity River”.

David Gaeuman, Ph.D., Senior Geomorphologist, Yurok Tribe, Design and Technical Services Program

David Gaeuman joined the Yurok Tribe Fisheries Department in 2019 after 13 years as a U.S. Bureau of Reclamation employee in the Weaverville TRRP office. Prior to arriving in Weaverville in 2006, he spent 3 years conducting sediment transport research in the Missouri River with the U.S. Geological Survey and worked in stream monitoring and restoration throughout the mountain west while earning a master’s degree in stream geomorphology at the University of Montana and a Ph.D. from Utah State University.

2024 Science Symposium Presentation

A decade of tracking coarse sediment augmentations: where has all the gravel gone?

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as David Gaeuman, Ph.D., Senior Geomorphologist, Yurok Tribe, Design and Technical Services Program presents, “A decade of tracking coarse sediment augmentations: where has all the gravel gone?”

Scott McBain, Fluvial Geomorphologist, McBain & Associates/Applied River Sciences, Consultant to Hoopa Valley Tribe Fisheries Department

Scott McBain is a fluvial geomorphologist at McBain Associates and has been a consultant for the Hoopa Valley Tribe Fisheries Department since 1989. He was one of many authors of the Trinity River Flow Evaluation Study, with his focus on the high flow and sediment management components. His discussion will focus on the evolution of the coarse sediment management strategy described in the Flow Study and ROD, and potential future coarse sediment management strategy considerations.

2024 Science Symposium Presentation

Background of sediment management as recommended in the Trinity River Flow Evaluation Study, and considerations for future coarse sediment management.

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Scott McBain, Fluvial Geomorphologist, McBain & Associates/Applied River Sciences, Consultant to Hoopa Valley Tribe Fisheries Department gives his presentation titled, “Background of sediment management as recommended in the Trinity River Flow Evaluation Study, and considerations for future coarse sediment management.“

James Lee, M.S., Implementation Branch Chief, Trinity River Restoration Program

James Lee is the Implementation Branch Chief at TRRP and is employed by the U.S. Bureau of Reclamation. His current role focuses on stream habitat restoration projects on a dam-regulated river, with a special emphasis on increasing native runs of Pacific salmon. James has worked for the program since 2012 as the staff Riparian Ecologist (employed by the Hoopa Valley Tribe) and then Science Coordinator.

Prior to his time at TRRP, he worked at an environmental consulting company, served the public as a wildlife biologist at a state natural resource trustee agency, and studied the ecology of several native desert fish species from a university in the southwestern U.S. He earned a B.S. in Wildlife and Fisheries Biology from the University of California, Davis, and a M.S. in Forest Resources from the University of Georgia.

2024 Science Symposium Presentation

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as James Lee, M.S., Implementation Branch Chief, Trinity River Restoration Program gives his presentation titled,  “Implications of variable summer baseflows to riparian vegetation in the Trinity River riparian corridor.“

Conor Shea, Ph.D., P.E., Civil Engineer: Hydraulics and Geomorphology, U.S. Fish and Wildlife Service, Arcata

Conor Shea specializes in the application of fluvial geomorphology, hydrology, and hydraulic analysis to develop aquatic habitat restoration projects. He has worked for government agencies, private consulting firms, and in academic settings. He provides technical assistance to a variety of partners that includes local and state government agencies, non-profit organizations, and private landowners. His work includes all phases of restoration project development from site assessment, monitoring, and concept development to preparing full construction plans and supervising construction.

Conor earned a B.S. in Forest Engineering and M.S. in Water Resources Engineering from the State University of New York College of Environmental Science and Forestry, and a Ph.D. in Fluvial Geomorphology from the Johns Hopkins University. Conor has worked for the U.S. Fish and Wildlife Service since 2003.

2024 Science Symposium Presentation

Evolving Paradigms of Trinity River Channel Form

Day 3 of the Trinity River Restoration Program Science Symposium covered Physical Channel Form. Listen in as Conor Shea, Ph.D., P.E., Civil Engineer in Hydraulics and Geomorphology for the U.S. Fish and Wildlife Service, Arcata gives his presentation titled, “Evolving Paradigms of Trinity River Channel Form”

Nate Mantua, Ph.D., Research Scientist, National Oceanic and Atmospheric Administration/National Marine Fisheries Science Center

Nate Mantua is a climate scientist with research focused on climate dynamics, climate impacts on natural resources, and the use of climate information in resource management. Much of his work has focused on climate, marine life, and fisheries in the North Pacific Ocean and western North America, including understanding climate impacts on Pacific salmon ecology and salmon fisheries. Nate is a former Associate Professor at the School of Aquatic and Fisheries Sciences (2006-2012) and founding member and co-director of the Climate Impacts Group, University of Washington (1995-2012).

2024 Science Symposium Presentation

Day one of the Trinity River Restoration Program Science Symposium covered Fish Populations. Listen in as Nate Mantua, Ph.D., Research Scientist, National Oceanic and Atmospheric Administration/National Marine Fisheries Science Center presents, “Monitoring to Science to Management: science-informed decision making to combat an aquatic parasite.“

Nicholas A. Som, Ph.D, Unit Leader, U.S. Geological Survey California Cooperative Fish and Wildlife Research Unit, CalPoly-Humboldt

Nicholas joined the U.S. Geological Survey California Cooperative Fish and Wildlife Research Unit in November of 2023, as the Unit Leader. Additionally, Nicholas teaches graduate courses on statistical methods common to fish and wildlife projects, such generalized linear models, applied Bayesian modeling at the Department of Fisheries Biology at California Polytechnic University, Humboldt.

Nicholas’ educational history includes an undergraduate mathematics degree from Regis University, a master’s degree in statistics from Washington State University, and he received his Ph.D. from Oregon State University where he studied time-series and spatial statistics for data originating from stream and river networks. Prior to joining the CRU, Nicholas was a statistician and program lead for the fish and aquatic conservation program at the Arcata US Fish and Wildlife office.

Nicholas’ research focuses on answering ecological questions with quantitative tools aimed to inform resource management decision makers. His main interests include water management and the ecology of pacific salmon, and his work includes both methods development and applied science projects. His applied work has ranged from the Columbia to Sacramento Rivers, but with most attention on the Klamath Basin. He frequently works on models for aquatic habitat, population dynamics, and disease dynamics.

2024 Science Symposium Presentation

Day one of the Trinity River Restoration Program Science Symposium covered Fish Populations. Listen in as Nicholas A. Som, Ph.D, Unit Leader, U.S. Geological Survey California Cooperative Fish and Wildlife Research Unit, CalPoly-Humboldt presents, “Monitoring to Science to Management: science-informed decision making to combat an aquatic parasite.“