Cooperative Fish and Wildlife Research Units Program: Nevada
Education, Research and Technical Assistance for Managing Our Natural Resources

Nevada Research Activities

Projects

Project	Completion Date
Habitat Suitability for Big Spring Spinedace (Lepidomeda mollispinis pratensis) in Meadow Valley Wash, Nevada	May 2025	The Big Spring Spinedace (Lepidomeda mollispinis pratensis) is a Federally threatened cyprind fish with a distribution limited to a single 5-km stream reach in Meadow Valley Wash, Lincoln County, NV. Little is known about the life history, habitat requirements, or demographics of this species. In 1994, the U.S. Fish and Wildlife Service set goals and objectives for recovery of BSS that included selection and establishment of refuge populations due to the vulnerability of the existing population to catastrophic events, human-induced habitat modification, and nonnative species introduction, and indicated that information collected on life history and habitat requirements should be utilized to evaluate potential refugia sites.This project is a collaboration among the U.S. Geological Survey, Nevada Cooperative Fish and Wildlife Research Unit, U.S. Fish and Wildlife Service, and the Nevada Department of Wildlife. We will establish criteria to evaluate Big Spring Spinedace habitat suitability via a literature review and pre-assessment analysis, conduct flow permanence surveys, monitor water levels and temperatures, and survey occupied and potential re-introduction sites for habitat suitability. We expect to recommend a prioritized list of sites that could be used as refuge population(s) for Big Spring Spinedace in and around Meadow Valley Wash, Nevada.	None

Research Publications

Research Publications	Publication Date
Sergeant, C.J., Bellmore, J.R., Bellmore, R.A., Falke, J.A., Mueter, F.J., Westley, P.A.H. 2023. Hypoxia vulnerability in the salmon watersheds of Southeast Alaska. Science of the Total Environment. dx.doi.org/10.1016/j.scitotenv.2023.165247	October 2023

Presentations

Presentations	Presentation Date
Schoen, E., Falke, J., Paul, J., Meyer, B., Neuswanger, J., Strohm, D., McKenna, B., Lynne, D., and Savereide, J. 2023. How Do Wildfires Affect Alaskan Chinook Salmon? Evidence from Rivers and Satellites. American Fisheries Society Annual Meeting, Grand Rapids, MI, August 20-24, 2023.	August 2023	Wildfires are becoming more frequent in Alaska's boreal ecosystems, but their effects on rivers and salmon are not well understood. One year after wildfires bisected an important Chinook salmon habitat, we found fire-affected sites were slightly warmer and more turbid than upstream reference sites, but food resources and juvenile salmon growth were similar. Satellite measurements across a broader study area showed historic wildfires warmed the land surface for > 15 years, resulting in complex e
Samuel, W. T., J. A. Falke, K. D. Tape, S. K. Panda, A. C. Seitz. 2023. When beavers get burned, do fish get fried? The role of beavers in mediating wildfire effects on freshwater fish habitat in boreal Alaska. American Fisheries Society 153^nd Annual Meeting, Grand Rapids, MI. August 20–24.	August 2023	Little is known about how wildfire affects fish habitat and populations in boreal streams despite the substantial impacts of fire on ecosystem processes, and how fire effects may be mediated by species interactions. This study will help to provide a better understanding of the role of beavers in maintaining diverse and productive aquatic habitats in riverscapes under changing wildfire conditions.
Rich, B., Westley, P., Sepulveda, A., Rinella, D., Falke, J., and E. Schoen. 2023. Introduced northern pike predation and consumption of juvenile salmon in a warming world. Matanuska-Susitna Salmon Habitat Partnership Symposium. 13-14 November, 2023. Palmer, AK.	November 2023	Global climate change may be exacerbating the impacts of invasive species such as Northern Pike in warming Alaska waters. We found that the direction and rate of predation by pike on juvenile salmon varied by species and with stream flow and temperature, and that pike may switch to alternative prey once salmon are extirpated. Thus, changing freshwater processes may directly affect predation rates of pike on salmon, but not total consumption.
Rich, B., Sepulveda, A., Falke, J., Schoen, E., Rinella, D., and P. Westley. 2024. Salmon declines coincide with climate mediated increases in consumption by a novel predator. Alaska Chapter American Fisheries Society Annual Meeting. 24-29 March 2024. Seward, AK.	March 2024	We explored the potential for synergistic effects of warming and invasion to better understand observed changes in a freshwater community comprised of socially valuable salmonid fishes.
K. Fitzgerald, L.H. Cheng, N. Boyles-Muehleck, R. Bellmore, J. Fellman, and J. Falke. 2023. Juvenile Coho Salmon growth patterns track biennial Pink Salmon spawning abundance fluctuations in a southeast Alaska watershed. National Meeting of the American Fisheries Society. 20-24 August, 2023,Grand Rapids, MI, USA.	August 2023	It is not well known whether adult salmon spawning abundance fluctuations confer disparate foraging and growth opportunities to stream-dwelling fish between years. We explored this hypothesis using a bioenergetic simulation paired with empirical field observations in a southeast Alaskan watershed that supports spawning salmon.
Hermus, J.H., J.D. Muehlbauer, D.J. Rinella, V.R. von Biela, J.A. Falke. 2023. The effects of water temperature and heat stress on juvenile Chinook Oncorhynchus tshawytscha, and Coho Salmon Oncorhynchus kisutch growth in the Deshka River watershed. Mat-Su Salmon Science and Conservation Symposium, Palmer, Alaska, 13-14 November 2023.	November 2023	This presentation is an introduction to John Hermus’ master’s thesis. This project will analyze data from the Deshka River watershed, with the goal of understanding the effects of water temperature and heat stress on juvenile Chinook and Coho Salmon growth in the face of a changing climate.
Hermus, J.H., J.D. Muehlbauer, D.J. Rinella, V.R. von Biela and J.A. Falke. 2024. The effects of water temperature and heat stress on juvenile Chinook (Oncorhynchus tshawytscha), and Coho Salmon (Oncorhynchus kisutch) growth in the Deshka River watershed. Alaska Chapter American Fisheries Society Annual Meeting, Seward, Alaska, 25-29 March 2024.	March 2024	This presentation is an introduction to John Hermus’ masters thesis. This project will analyze data from the Deshka River watershed, with the goal of understanding the effects of water temperature and heat stress on juvenile Chinook and Coho Salmon growth in the face of a changing climate.
Fitzgerald, K., R. Bellmore, J. Fellman, C. Delbecq, and J. Falke. 2023. Stream hydrology and a salmon pulse subsidy shape juvenile salmonid foraging patterns in a southeast Alaska watershed. National Meeting of the American Fisheries Society. August 20 -24, 2023, Grand Rapids, MI, USA.	August 2023	Consumers capacity to exploit pulse subsidy resources may be influenced by antecedent environmental conditions such as stream flow. For juveniles of two salmonid species, we observed that consumption optima coincided with baseflow and high flow conditions, minima were observed during severe low-water and intermediate flow values, and interannual hydrologic variation shifted growth trajectories among years, potentially impacting access to pulse subsidies.
Falke, J.A., Dunham, J.B., Rosenberger, A.E., Thurow, R.F., Dolloff, A., Howell, P.J., and W.C. Saunders. 2024. Standardized Sampling of Coldwater Fish in Wadeable Streams in North America. World Fisheries Congress, Seattle, WA. 3-9 March, 2024.	March 2024	In this presentation we describe our textbook chapter on standardized techniques for quantitative sampling of fishes in North American coldwater streams focused on backpack electrofishing, snorkeling, and redd count methods. We emphasize training, method validation, and obtaining unbiased measurements and estimates within sampling units as critical components of any coldwater stream standardized sampling program.
Falke, J.A. and J.D. Paul. 2023. Landscape-scale prediction of freshwater habitat potential for Chinook Salmon (Oncorhynchus tshawytscha) across the Yukon and Kuskokwim River basins, Alaska. American Fisheries Society Annual Meeting, Grand Rapids, MI. 20 – 24 August 2023.	August 2023	Research into environmental factors involved in the decline of Yukon River Chinook Salmon stocks has exposed information gaps regarding fine-scale freshwater habitat quality known to influence population productivity. We developed spatially-explicit habitat suitability models for spawning and rearing life-stages based on fluvial geomorphic attributes, and are developing a decision support tool based on input from stakeholders tailored to the specific applications of this dataset.
Falke, J.A. 2024. What is the Nevada Cooperative Fish & Wildlife Research Unit? Graduate Education, Collaborative Research, and Technical Assistance for Fish and Wildlife Conservation and Management in Nevada and Beyond. California-Nevada Chapter American Fisheries Society Biennial Meeting. 9-12 April, 2024, Redding, CA.	April 2024	Description of the Nevada Cooperative Fish and Wildlife Research Unit.
Falke, J.A. 2023. What is the Nevada Cooperative Fish & Wildlife Research Unit? Graduate Education, Collaborative Research, and Technical Assistance for Conservation of Great Basin Fish and Wildlife. Desert Fishes Council Annual Meeting. 15-18 November, 2023, Bishop, CA.	November 2023	Description of the Nevada Cooperative Fish and Wildlife Research Unit.

Data or Software Releases

Type	Citation	Publication Date
Data Release	Sergeant, C. J. and Falke, J. Code to Support Hydrologic variability and a pulse subsidy shape juvenile salmonid foraging patterns in a southeast Alaska watershed. Version 1.0.0: U.S. Geological Survey software release. Reston, Va. https://doi.org/10.5066/P9TA6PK	October 2023
Data Release	Sergeant, C. J. and Falke, J. 2023. Data describing hypoxia vulnerability in the salmon watersheds of Southeast Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9VAKF20.	May 2021
Data Release	Jalbert, C.S., Sepulveda, A.J., and Falke, J.A., 2021, Data describing vulnerability of Pacific salmon to invasion of northern pike (Esox lucius) in southcentral Alaska, 2017-2019: U.S. Geological Survey data release, https://doi.org/10.5066/P9UJAH16.	June 2020
Software Release	Fitzgerald, K.A, and Falke, J., 2023, Stream hydrology and a pulse subsidy shape patterns of fish foraging: U.S. Geological Survey data release, https://doi.org/10.5066/P9EEEDB1.	November 2023