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Person

Jeffrey A Falke

Unit Leader - Fish, Research Fish Biologist

Email: jfalke@usgs.gov
Office Phone: 775-682-9510
ORCID: 0000-0002-6670-8250

Location
1664 N. Virginia Street
Mail Stop 405
Reno , NV 89557
US
Abstract (from Fisheries Magazine): Ecosystem transformation can be defined as the emergence of a self‐organizing, self‐sustaining, ecological or social–ecological system that deviates from prior ecosystem structure and function. These transformations are occurring across the globe; consequently, a static view of ecosystem processes is likely no longer sufficient for managing fish, wildlife, and other species. We present a framework that encompasses three strategies for fish and wildlife managers dealing with ecosystems vulnerable to transformation. Specifically, managers can resist change and strive to maintain existing ecosystem composition, structure, and function; accept transformation when it is not feasible...
Categories: Publication; Types: Citation
Climate change is an important factor affecting fish globally. This site provides a comprehensive database of peer-reviewed literature available on how climate change has impacted and will continue to impact inland fishes worldwide. These studies have been compiled through an extensive, systematic primary literature review to identify English-language, peer-reviewed journal publications with projected and documented examples of climate change impacts on inland fishes globally. From this standardized database of existing literature, we can examine global patterns in climate change impacts on inland fish. Following a decision path based on knowledge of how climate has been documented to affect fish biology in five...
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Pulsed subsidy events create ephemeral fluxes of hyper-abundant resources that can shape annual patterns of consumption and growth for recipient consumers. However, environmental conditions strongly affect local resource availability for much of the year, and can heavily impact consumer foraging and growth patterns prior to pulsed subsidy events. Thus, a consumer’s capacity to exploit pulse subsidy resources may be influenced by antecedent environmental conditions, but this has rarely been shown in nature and is unknown in aquatic ecosystems. We sampled fish at a high frequency (daily - weekly measurements) to examine the importance of hydrologic variation and a salmon pulse subsidy on the foraging patterns of two...
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This .zip file contains five products that will allow users to recreate the analyses and spatial data figures used in Sergeant et al. 2023, Hypoxia Vulnerability in the Salmon Watersheds of Southeast Alaska: 1) Hypoxia vulnerability calculations (.csv file) at water temperature monitoring sites, 2) Hypoxia vulnerability calculations (.csv file) for stream reaches near hatchery release sites, 3) Habitat characteristics (.csv file) at water temperature monitoring sites, 4) R code (.R file) for recreating Figure 3, modeled contours of the estimated number of pink salmon/m2 to create hypoxia in Southeast Alaska streams across all potential combinations of velocity, depth, and water temperature, 5) Esri map package (.mpk...
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Viable sockeye salmon populations are critical to the economy, culture, and freshwater ecosystems of Bristol Bay in Western Alaska, and it is unclear how populations might respond to warming temperatures during the critical life history stages of spawning and embryo incubation. The overarching goal of the project is to understand how temperature might influence population-specific patterns of embryo incubation, timing of hatching and fry emergence, and sockeye salmon embryo survival. By combining analyses of data from two large lake systems in the Kvichak watershed, laboratory rearing experiments to elucidate functional relationships, and simulation modeling, this project quantifies biological responses to changing...
Categories: Data, Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Academics & scientific researchers, CLIMATE CHANGE IMPACT ASSESSMENT MODELS, CLIMATE CHANGE IMPACT ASSESSMENT MODELS, DATA REFORMATTING, DATA REFORMATTING, All tags...
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