Education
Ph.D. Ecology Evolution and Conservation Biology, University of Nevada-Reno
Specialty
Aquatic Ecology
Research Interests
Landscape ecology of aquatic ecosystems, conservation biology of focal species, ecology of natural disturbance, biological invasions, monitoring
Personal Interests
Australian cattledogs, mycophilia, water sports
The Elwha River Restoration Project...
... has reconnected the water, salmon, and sediment of a pristine river and coast of the Olympic Peninsula of Washington. Coordinated by the National Park Service, restoration of the Elwha River included the removal of two large dams that had blocked salmon and sediment passage for almost 100 years. The largest dam removal in U.S. history began in...
Native lampreys are culturally significant fishes for tribal communities in Oregon. As such, the USGS has begun working with the Cow Creek Band of Umpqua Tribe of Indians to study changes that may be affecting habitat for native Pacific and western brook lampreys in the Umpqua River basin.
Chinook Salmon and Pacific Lamprey are culturally significant fishes to the Tribal community along the Siletz River, Oregon. The USGS has begun studying how streamflow and bedload conditions may influence mainstem spawning habitats.
PRObability of Streamflow PERmanence (PROSPER)
Rivers and streams are constantly changing. Streamflows can change throughout the year and between years due to snowmelt, precipitation, diversions, and return flows. For many streams, these fluctuations determine whether a stream has year-round flow or not. PROSPER is a project initiated to better understand what causes these fluctuations...
Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
Invasive species are a growing threat to native species and ecosystem processes in fresh waters. The Introducing non-native fish into an area may have no effect, little current effect, or the potential to seriously impact the native species, possibly resulting in their extinction. We conduct research to address the causes of invasions and their impacts. We also provide technical support for...
Restoration of aquatic ecosystems involves a broad spectrum of active and passive efforts. Passive efforts rely on natural recovery of ecosystems, such as land use practices that protect riparian zones and sources of wood and sediment that drive the geomorphic and associated biological functions in streams. Active efforts involve more direct intervention, usually applied to specific locations...
Effects of changing climate on aquatic ecosystems requires understanding a complex series of interactions between terrestrial climates, their corresponding impacts on hydrological processes, and ultimately a suite of biological responses. These uncertainties stand in contrast to the urgent need for reliable information to be used in developing long-term strategies for climate adaptation to...
Many species exhibit diverse behaviors that translate into different patterns of habitat use and demography. Diversity within species can be related to a complex array of processes, including genetic and maternal influences, and external environmental drivers. Our work addresses life history diversity in salmon and trout, including Pacific salmon, steelhead and rainbow trout, cutthroat trout,...
View this webinar to learn about a new initiative to address knowledge gaps in water availability at the landscape scale.
View this webinar to learn more about threatened bull trout.
These tabular, spatial, and code data sets were created in support of a stream temperature monitoring study in the Willow-Whitehorse and Little Blitzen watersheds in southeastern Oregon from 2011-2015.
Stream segments, aquatic organism captures, stream surveys, and road-stream crossings described by these metadata accompany a 2012 electrofishing study of the distribution and abundance of aquatic organisms conducted by the U.S. Geological Survey, and the U.S. Forest.
Resource managers in the Pacific Northwest (USA) actively thin second-growth forests to accelerate the development of late-successional conditions and seek to expand these restoration thinning treatments into riparian zones. Riparian forest thinning, however, may impact stream temperatures–a key water quality parameter often regulated to protect...
Roon, David; Dunham, Jason B.; Groom, Jeremiah D When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species:...
Martens, Kyle D; Dunham, Jason B. Beaver-related restoration is a process-based strategy that seeks to address wide-ranging ecological objectives by reestablishing dam building in degraded stream systems. Although the beaver-related restoration has broad appeal, especially in water-limited systems, its effectiveness is not yet well documented. In this article, we present a process...
Nash, Caroline; Grant, Gordon E.; Charnley, Susan; Dunham, Jason B.; Gosnell, Hannah; Hausner, Mark B.; Pilliod, David S.; Taylor, Jimmy D. Through their multiple functions, refuges may be important for stream‐living fishes, particularly during stressful events such as seasonal low flow or drought. Coastal Cutthroat Trout Oncorhynchus clarkii clarkii is an ideal study organism to understand the importance of refuge. During seasonal low flow, lower water levels limit access...
Penaluna, Brooke E; Dunham, Jason B.; Andersen, Heidi V This study developed a spatially explicit framework to support the conservation of Western Brook Lamprey Lampetra richardsoni and Pacific Lamprey Entosphenus tridentatus in the Umpqua River basin, Oregon. This framework identified locations within the river network likely to support “potential burrowing habitat” for lamprey...
Jones, Krista; Dunham, Jason B.; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Coates, Kelly; Mackie, Travis
The accurate mapping of streams and their streamflow conditions in terms of presence or absence of surface water is important to both understanding physical, chemical, and biological processes in streams and to managing land, water, and ecological resources. This document describes a field form, FLOwPER (FLOw PERmanence), available within a mobile...
Jaeger, Kristin L.; Burnett, Jonathan; Heaston, Emily D.; Wondzell, Steve M.; Chelgren, Nathan; Dunham, Jason B.; Johnson, Sherri; Brown, Mike Ecological resources for fishes in stream food webs shift over space and time, providing a complex template of available resources that can be used for growth. We tracked water temperature in conjunction with young-of-year Coho Salmon size, growth, and diet in 2 streams with contrasting thermal regimes: a groundwater stream with colder...
Campbell, E Y; Dunham, Jason B.; Reeves, G H The seasonal and inter-annual variability of flow presence and water temperature within headwater streams of the Great Basin of the western United States limit the occurrence and distribution of coldwater fish and other aquatic species. To evaluate changes in flow presence and water temperature during seasonal dry periods, we developed spatial...
Gendaszek, Andrew S.; Dunham, Jason B.; Torgersen, Christian E.; Hockman-Wert, David P; Heck, Michael; Thorson, Justin Martin; Mintz, Jeffrey Michael; Allai, Todd Multiple restoration actions have been implemented in response to declining salmon populations. Among these is the addition of salmon carcasses or artificial nutrients to mimic marine-derived nutrients historically provided by large spawning runs of salmon. A key assumption in this approach is that increased nutrients will catalyze salmon...
Benjamin, Joseph R.; Bellmore, James R; Whitney, Emily; Dunham, Jason B. The likelihood that fish will initiate spawning, spawn successfully, or skip spawning in a given year is conditioned in part on availability of energy reserves. We evaluated the consequences of spatial heterogeneity in thermal conditions on the energy accumulation and spawning potential of migratory bull trout (Salvelinus confluentus) in a...
Benjamin, Joseph R.; Vidergar, Dmitri T; Dunham, Jason B. The introduction of Common Carp (Cyprinus carpio) into North American waterways has led to widespread alteration of aquatic ecosystems. Control of this invader has proven extremely difficult due to its capacity for rapid population growth. To help understand how Common Carp can potentially be controlled we developed a population dynamics model (...
Pearson, James B; Dunham, Jason B.; Bellmore, J Ryan; Lyons, Donald E. The decision to reintroduce a species can be difficult owing to conflicting opinions and objectives, as well as uncertainty of the outcome. Structured decision making addresses these considerations by identifying realistic fundamental objectives and building achievable management alternatives, within a quantitative modeling framework. The process...
Benjamin, Joseph R.; Brignon, William R.; Dunham, Jason B.
Few would believe the importance of freshwater mussels to scientists here in the Pacific Northwest. These little-known and often-ignored organisms may live for over a century on the bottoms of lakes, rivers, and streams. Freshwater mussels have a story to tell, and researchers have developed a way of ‘reading’ this story. USGS Aquatic Biologist Jason Dunham discusses his
Resource managers are interested in understanding whether thinning trees in riparian forests could help existing trees grow larger, eventually providing a source of large woody debris, promoting riparian zone heterogeneity, and enhancing riparian biodiversity.
Many stream studies in the Pacific Northwest have focused solely on coastal cutthroat trout, the most prevalent species, though it is well-known that interactions within the total species assemblage can be important.
Beaver-related restoration is a process-based strategy that seeks to re-establish dam building in degraded stream systems by translocating beavers to streams where dams are desired, building artificial structures that mimic beaver dams, or restoring riparian vegetation to attract beavers.
Interactions among river conditions that influence fish migration success make it challenging to assess management options.
During seasonal low flow in streams, survival of fish is low and predation risk is high, which could be explained by a lack of available cover.
Lampreys in the Umpqua River basin face multiple threats, including predation by nonnative fish such as smallmouth bass.
Novel forms of drought are emerging globally, due to climate change, shifting teleconnection patterns, expanding human water use, and a history of human influence on the environment that increases the probability of transformational ecological impacts.
The first year of life is perilous for a salmonid, typified by a critical period of post-emergence mortality.
Watershed assessments are often used to prioritize restoration, yet these assessments primarily focus on geomorphic conditions and less frequently incorporate abiotic factors, such as water chemistry and temperature, and biotic factors, such as the structure of food webs.
Impacts from biological invasions are especially prevalent in freshwaters. Conventional approaches to managing invaders such as prevention, control, or eradication can be variably effective, difficult to implement, or socially undesirable.
USGS and USFS develop a mobile application field form for rapid collection of flow/no flow observations.
Multiple restoration actions have been implemented in response to declining salmon populations, including adding salmon carcasses or artificial nutrients to mimic marine-derived nutrients historically provided by large spawning runs of salmon.