Date of Award:
5-2008
Document Type:
Thesis
Degree Name:
Master of Science (MS)
Department:
Watershed Sciences
Committee Chair(s)
Phaedra Budy
Committee
Phaedra Budy
Committee
Brett Roper
Committee
David Tarboton
Abstract
Due to the significant threats posed by nonnative fish species worldwide, it is important to understand how life-history strategies of individual species interact with environmental conditions to explain the success or failure of nonnative fish invasions. Brown trout are prolific invaders, but often exhibit upstream distributional limits in Intermountain West streams, potentially due to a maladaptive reproductive life-history strategy influenced by hydrologic conditions in high-elevation areas. We used redd counts, egg survival experiments, and temperature modeling to investigate the reproductive life-history strategy of brown trout and its potential for success along an elevational stream gradient. We documented brown trout spawning in stream reaches at elevations higher than where we typically encounter brown trout during summer electrofishing surveys, indicating the potential for upstream invasion. We observed a decline in egg survival at higher elevation, cooler water sites, but did not document complete recruitment failure at these sites, again indicating the potential for successful invasion at this life-stage. Temperature data indicate that during most years, incubating brown trout eggs would likely fail to emerge from the gravel prior to peak spring flows in these high-elevation stream reaches, suggesting that damaging spring floods may cause significant egg and sac-fry mortality at high elevations, and may determine invasion success in these areas. Our results highlight the importance of identifying specific mechanisms of recruitment failure in order to better predict nonnative fish invasions in the future.
Checksum
21caa108e6b4648c6f12ff79ad972f09
Recommended Citation
Wood, Jeremiah, "An Investigation of the Early Life-History of Brown Trout (Salmo trutta) and Potential Influences on Invasion Success in the Logan River, Utah" (2008). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 131.
https://digitalcommons.usu.edu/etd/131
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