Life history diversity of Snake River finespotted cutthroat trout: managing for persistence in a rapidly changing environment

North American Journal of Fisheries Management
By: , and 

Links

Abstract

Over the last century, native trout have experienced dramatic population declines, particularly in larger river systems where habitats associated with different spawning life history forms have been lost through habitat degradation and fragmentation. The resulting decrease in life history diversity has affected the capacity of populations to respond to environmental variability and disturbance. Unfortunately, because few large rivers are intact enough to permit full expression of life history diversity, it is unclear what patterns of diversity should be a conservation target. In this study, radiotelemetry was used to identify spawning and migration patterns of Snake River Finespotted Cutthroat Trout Oncorhynchus clarkii behnkei in the upper Snake River. Individuals were implanted with radio tags in October 2007 and 2008, and monitored through October 2009. Radio-tagged cutthroat trout in the upper Snake River exhibited variation in spawning habitat type and location, migration distance, spawn timing, postspawning behavior, and susceptibility to mortality sources. Between May and July, Cutthroat Trout spawned in runoff-dominated tributaries, groundwater-dominated spring creeks, and side channels of the Snake River. Individuals migrated up to 101 km from tagging locations in the upper Snake River to access spawning habitats, indicating that the upper Snake River provided seasonal habitat for spawners originating throughout the watershed. Postspawning behavior also varied; by August each year, 28% of spring-creek spawners remained in their spawning location, compared with 0% of side-channel spawners and 7% of tributary spawners. These spawning and migration patterns reflect the connectivity, habitat diversity, and dynamic template of the Snake River. Ultimately, promoting life history diversity through restoration of complex habitats may provide the most opportunities for cutthroat trout persistence in an environment likely to experience increased variability from climate change and disturbance from invasive species.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Life history diversity of Snake River finespotted cutthroat trout: managing for persistence in a rapidly changing environment
Series title North American Journal of Fisheries Management
DOI 10.1080/02755947.2015.1044625
Volume 35
Issue 4
Year Published 2015
Language English
Publisher American Fisheries Society
Contributing office(s) Northern Rocky Mountain Science Center
Description 13 p.
First page 789
Last page 801
Country United States
State Wyoming
Other Geospatial Snake River
Online Only (Y/N) N
Additional Online Files (Y/N) N