I am a USGS emeritus research biologist and affiliate assistant professor in the Department of Ecology at Montana State University. My research is focused on the factors that influence fish abundance, distribution, and life history within, and among watersheds, and how these relationships change in through time.
Research Interests: My interest in the role of disturbance in shaping the aquatic systems has led to research on the interactions among landscape-scale environmental features, instream habitat characteristics, and cutthroat trout abundance and distribution. Currently my research is focused on the effects of fire, timber harvest, invasive species, and climate change on persistence of native trout in the Intermountain West. I have been involved with the lake trout issue in Yellowstone Lake since these invaders were first discovered in 1994 and act as chair of the lake trout suppression independent scientific review panel that was formed 2008.
Recent Accomplishments
Education
- Ph.D. Fisheries Science. 1994. Oregon State University
- M.S. Wildlife Science. 1973. Utah State University
- B.S. Biology. 1970. University of New Mexico
Professional Studies/Experience
Mentorship/Outreach
Professional societies/affiliations/committees/editorial boards
Honors, awards, recognition, elected offices
Scientific/Oral Presentations, Abstracts
Science and Products
FAQ on Invasive Lake Trout in Yellowstone Lake
These Frequently Asked Questions and responses were developed by USGS and their partners with the Lake Trout Suppression Scientific Review Panel *. The purpose of these FAQs is to provide answers to several of the more common questions concerning the lake trout suppression program in Yellowstone Lake, within Yellowstone National Park, and provide information about the current status of the program...
Predicting Effects of Climate Change on Native Fishes in Northern Great Plains Streams
The Northern Great Plains of North America are a region of profound global importance because organisms that live in these semi-arid prairie environments have developed a unique ability to live through conditions of extreme heat, cold, floods, and drought. Prairie streams are essential components of these ecosystems because they provide critical “green lines” of habitat for both aquatic and...
Estimating Future Streamflow in Eastern Montana Using the Precipitation-Runoff Modeling System and the RegCM3 Regional Climate Model
Streams in the Northern Great Plains provide critical “green lines” of habitat for aquatic and terrestrial wildlife. However, changes in water quantity associated with global climate change may transform some prairie streams from essential refuges to habitats no longer capable of supporting fishes. Although studies have examined climate change effects on larger river basins across the United...
Yellowstone Lake Acoustic Biotelemetry Project Home Page
Fishery biologists and managers are increasingly consumed with the recovery and restoration of native trout and salmon throughout the western United States. These fish historically inhabited a variety of freshwater habitats, but have declined due to habitat degradation, fragmentation and introduction of nonnative species. Introduced fishes constitute a major threat to the persistence of native...
Bob Gresswell's Past Projects
Bob Gresswell's Past Projects
Understanding Extreme Climate Events in the North Central U.S.
The climate of the North Central U.S. is driven by a combination of factors, including atmospheric circulation patterns, the region’s complex topography which extends from the High Rockies to the Great Plains, and variations in hydrology. Together, these factors determine the sustainability of the region’s ecosystems and the services that they provide communities. In order to understand the vuln
The Potential Influence of Changing Climate on the Persistence of Native Salmonids
Understanding how climate change will influence habitat for interior species of native salmonids is critical for effective management and recovery of these species. The US Department of the Interior, the US Department of Agriculture, state fisheries managers, and non-governmental organizations are increasingly challenged in attempting the recovery and restoration of native trout and salmon through
Science and Products
- Science
FAQ on Invasive Lake Trout in Yellowstone Lake
These Frequently Asked Questions and responses were developed by USGS and their partners with the Lake Trout Suppression Scientific Review Panel *. The purpose of these FAQs is to provide answers to several of the more common questions concerning the lake trout suppression program in Yellowstone Lake, within Yellowstone National Park, and provide information about the current status of the program...Predicting Effects of Climate Change on Native Fishes in Northern Great Plains Streams
The Northern Great Plains of North America are a region of profound global importance because organisms that live in these semi-arid prairie environments have developed a unique ability to live through conditions of extreme heat, cold, floods, and drought. Prairie streams are essential components of these ecosystems because they provide critical “green lines” of habitat for both aquatic and...Estimating Future Streamflow in Eastern Montana Using the Precipitation-Runoff Modeling System and the RegCM3 Regional Climate Model
Streams in the Northern Great Plains provide critical “green lines” of habitat for aquatic and terrestrial wildlife. However, changes in water quantity associated with global climate change may transform some prairie streams from essential refuges to habitats no longer capable of supporting fishes. Although studies have examined climate change effects on larger river basins across the United...Yellowstone Lake Acoustic Biotelemetry Project Home Page
Fishery biologists and managers are increasingly consumed with the recovery and restoration of native trout and salmon throughout the western United States. These fish historically inhabited a variety of freshwater habitats, but have declined due to habitat degradation, fragmentation and introduction of nonnative species. Introduced fishes constitute a major threat to the persistence of native...Bob Gresswell's Past Projects
Bob Gresswell's Past ProjectsUnderstanding Extreme Climate Events in the North Central U.S.
The climate of the North Central U.S. is driven by a combination of factors, including atmospheric circulation patterns, the region’s complex topography which extends from the High Rockies to the Great Plains, and variations in hydrology. Together, these factors determine the sustainability of the region’s ecosystems and the services that they provide communities. In order to understand the vulnThe Potential Influence of Changing Climate on the Persistence of Native Salmonids
Understanding how climate change will influence habitat for interior species of native salmonids is critical for effective management and recovery of these species. The US Department of the Interior, the US Department of Agriculture, state fisheries managers, and non-governmental organizations are increasingly challenged in attempting the recovery and restoration of native trout and salmon through - Publications