Bull Trout and Climate Change - Risks, Uncertainties and Opportunities for Mapping the Future

Bull trout are a federally listed, native charr species distributed throughout the Pacific Northwest. Among the critical requirements for this species are a need for large, interconnected habitats of cold water. Much uncertainty exists regarding the future of bull trout and their habitats given environmental trends associated with a warming climate and increasing fire activity. Presentations at this symposium provide an overview of bull trout, their relationship to climate, and alternatives for modeling future habitat and population distributions.

Videos and Abstracts of the 2008 Western Division Meeting of the American Fisheries Society

Monitoring Bull Trout Populations

Bull trout are native to much of the Pacific Northwest, but population declines during the 20th century prompted listing under the Endangered Species Act. Several national forests have also selected bull trout as a Management Indicator Species, which makes monitoring a priority. Monitoring protocols have traditionally focused on tracking site level abundance, but these approaches can be costly to apply across broad areas and are being replaced in some instances by distributional monitoring. Researchers at the Boise Aquatic Sciences Lab have adapted distributional approaches for bull trout to create a monitoring protocol that can be applied rapidly and inexpensively while providing powerful trend detection across broader areas relevant to land management.

Briefing Paper  |  A Watershed-scale Monitoring Protocol for Bull Trout (RMRS-GTR-224)

Invasive Species

Invasive Species: Managing for Native Trout

Invasive Species are one of the most important threats to the integrity of stream ecosystems.  Although widely distributed, invasions and the disruption of native communities are not universal.  Understanding where invasion risks are most important and what can be done about it will be key to prioritization of limited management resources.

Briefing Paper

Nonnative Fish Removal

Nonnative brook trout have invaded and replaced native cutthroat trout in many Rocky Mountain streams. Methods to remove brook trout, such as chemical treatment and intensive electrofishing, are expensive, time-consuming, and sometimes controversial. An alternative technique used in control of unwanted insects, pheromone lures and traps, may be applicable to fish.

Briefing Paper

Stream Temperature Modeling

Stream thermal regimes are important within regulatory contexts and strongly affect aquatic ecosystems. Numerous approaches have been developed for modeling stream temperatures, but broad application of these models to USFS lands has been constrained by data limitations and poor predictive ability. RMRS scientists have developed an approach to modeling stream temperatures that requires a minimum of field effort by using existing temperature records in combination with GIS and remote sensing technologies. The approach is being applied in a central Idaho watershed to map thermal habitat networks for native fish species, but could also be used to forecast future habitat distributions, improve understanding of factors affecting stream temperatures, determine compliance with water quality standards, or optimize temperature sampling strategies. 

Briefing Paper  |  Stream Temperature Modeling Website