John Hayes, Ph.D., Freshwater Fisheries Scientist – Cawthron Institute, New Zealand

John Hayes is a freshwater fisheries scientist from Nelson, New Zealand, recently retired from the Cawthron Institute, where he retains an emeritus position. John has special expertise in recreational trout and salmon fisheries, instream habitat modelling and salmonid foraging and bioenergetics modelling. He has led and supervised research and consulting projects on freshwater fisheries, habitat assessment, limiting factors, environmental flow regimes and effects of hydro-power and irrigation schemes.

Over the last two decades of his career John led a series of research projects with New Zealand and USA scientists developing process-based models integrating river hydraulics, invertebrate drift transport and the bioenergetics of drift feeding to predict effects of flow, water temperature and clarity on stream salmonid growth and carrying capacity. Much of his research has been aimed at understanding how rivers work in relation to sustaining fish populations and fisheries to inform environmental effects assessment. He has undertaken fisheries related environmental consulting widely in New Zealand and contributed to a project in Oregon. His salmonid bioenergetics models have been applied in New Zealand, Australia, and the USA – including the North Umpqua and Colorado rivers, and Columbia River tributaries.

John’s interests in fish ecology arose from a life-long passion for fishing. Over his career he has enjoyed communicating freshwater ecology and fisheries science in popular press. He has been a regular writer for Fish & Game New Zealand magazine, also published in Flylife Magazine (Australia), and co-authored the book ‘The Artful Science of Trout Fishing’.

2024 Science Symposium Presentation

Day two of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as John Hayes, Ph.D., Freshwater Fisheries Scientist – Cawthron Institute, New Zealand presents, “How flow affects aquatic invertebrate habitat and drift, and salmonid net energy intake and instantaneous carrying capacity.”

Eli Asarian, Aquatic Ecologist/Hydrologist, Riverbend Sciences

Eli Asarian is an aquatic ecologist/hydrologist and founder of the Eureka-based consulting firm Riverbend Sciences. He has worked in California and Oregon watersheds for over 20 years. He specializes in statistical analysis of large, complex datasets and has authored or co-authored over 25 technical analyses on flow, water temperature, water quality, and algae.

Since 2015, he has completed seven water temperature studies in the Klamath-Trinity river basin, including “Wildfire smoke cools summer river and stream water temperatures” and the TRRP-funded “Synthesizing 87 years of scientific inquiry into Trinity River water temperatures.” He has assisted with development and implementation of salmon and steelhead recovery plans throughout California, and serves as president of the Salmonid Restoration Federation. Additional info HERE.

2024 Science Symposium Presentation

Day two of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Eli Asarian, Aquatic Ecologist/Hydrologist, Riverbend Sciences presents, “Water temperatures in the Klamath-Trinity Basin: flow, other key drivers, and climate change implications.”

Seth Naman, Fisheries Biologist, NOAA Fisheries – National Marine Fisheries Service

Seth earned a Bachelor of Science from Oregon State University and a Masters of Science in Fisheries Biology from Humboldt State University. After positions with Idaho Fish and Game, the National Park Service, and the Yurok Tribe, he began working for the National Marine Fisheries Service in 2008. Seth participates in several of the TRRP’s work groups, the Trinity River Hatchery Technical team, and he’s an alternate on the TMC. He is a longtime resident of Humboldt County and enjoys fishing, hunting, kayaking, and rafting.

2024 Science Symposium Presentation

Day 2 of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Seth Naman, Fisheries Biologist, NOAA Fisheries – National Marine Fisheries Service presents, “A method to implement natural flow regimes for regulated rivers.”

Presentation Coming Soon!

Derek Rupert, Fish Biologist – Bureau of Reclamation, Northern California Area Office

Derek Rupert is a fish biologist with the Bureau of Reclamation – Northern California Area Office, a position he has held since 2017.  He previously worked for the US Fish and Wildlife Service as part of the Trinity River salmon population monitoring program and with the National Park Service in Yellowstone performing cutthroat trout restoration.  He has Master of Science degree in biology from Western Kentucky University and a Bachelor of Science degree in fisheries biology from Mansfield University of Pennsylvania. 

2024 Science Symposium Presentation

Day 2 of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Derek Rupert, Fish Biologist for the Bureau of Reclamation, Northern California Area Office presents, “Seasonally Oscillating Hydrographs.“

Don Ashton, Senior Aquatic Herpetologist/Ecologist – McBain Associates/Applied River Sciences

Don Ashton is a professional herpetologist and aquatic ecologist. He earned a Bachelor of Science in Biodiversity and Master of Arts in Biology from Humboldt State University. For three decades, his research in the government and private sectors has focused on river restoration to support ecosystem function and inform land use and resource management decisions with a focus on Northwestern Pond Turtle and Foothill Yellow-legged Frog conservation.

2024 Science Symposium Presentation

Frogs and Turtles informing flow management and river restoration.

Day 2 of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Don Ashton, Senior Aquatic Herpetologist/Ecologist – McBain Associates/Applied River Sciences presents , “Frogs and Turtles informing flow management and river restoration.“

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 the relationship 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.

2024 Science Symposium Presentation

Thermal stratification in pools on the Trinity River.

Day 2 of the Trinity River Restoration Program Science Symposium covered Habitat, Flow and Temperature. Listen in as Todd Buxton, Ph.D., Hydrologist/Geomorphologist, Trinity River Restoration Program presents , “Thermal stratification in pools on the Trinity River.”

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”.