Dams created by North American Beaver (Castor canadensis) have numerous effects on the stream habitat use of trout. The extent to which beaver dams act as movement barriers to salmonids and whether successful dam passage differs among species is a topic in need of further research. We investigate the passage of beaver dams by three species of trout in two northern Utah tributaries. We fitted 1381 trout with passive integrated transponder tags located above and below 22 known beaver dams to establish whether fish passed dams and to identify downstream and upstream passes; 187 trout were observed passing a beaver dam. Native Bonneville cutthroat trout (Oncorhynchus clarki utah) passed dams more frequently than both non-native brown trout (Salmo trutta) and brook trout (Salvelinus fontinalis). It was determined that spawning timing affected seasonal changes in dam passage for each species. Physical characteristics and location of individual beaver dams affected the passage of each species. Movement behaviors of each trout species were also evaluated to help explain dam passage. This data suggests that beaver dams are not acting as barriers to movement for cutthroat and brook trout which have both co-evolved with North American beaver but may be impeding the movements of invasive brown trout.
- This research is one of the first studies that quantitatively documents the passage of three species of trout passing beaver dams
- It is important to watershed and fisheries managers in areas where beaver are present
View Larger Map
We used passive integrated transponder (PIT) tags in fish to track their locations. We identifed fish located above and below beaver dams to identify passage and direction of passage. We also evaluated passage by fish species, size class, and passage timing.
- All three species of trout were observed passing beaver dams.
- Bonneville cutthroat trout, which have coevolved with North American beaver, were more adept than brown trout at passing beaver dams in both directions
- While brook trout also coevolved with North American beaver, they passed dams less frequently due to much smaller overall movement behaviors and only being located in the upper reaches of Spawn Creek
- Future work is needed to identify the actual mechanisms behind dam passage. How do fish pass dams? Do they jump the dam, swim through the dam, or go around a dam using side channels, or a combination of the three? In-stream antenna arrays place above, below, and in side channels would help to answer this question.
- This project is a follow up to the USFS: Comparison of Traditional Versus Ground-Based LiDaR Instream Haibtat Assessments
- 2011. Lokteff R, Roper BB and Wheaton JM. Ground Based Lidar and PIT Tags: Does High Resolution Data Improve Our Understanding of a Fish's Utilization of Habitat? , American Fisheries Society 141st Annual Meeting: Seattle, WA.
- 2011. Lokteff R, Wheaton JM and Roper BB. Spatial Distribution and Species Segregation of Bonneville Cutthroat Trout, Brown Trout, and Brook Trout, American Fisheries Society 141st Annual Meeting: Seattle, WA, P-96 pp.
- 2011. Lokteff RL, DeMeurichy KD and Wheaton JM. 2011. High Resolution Mapping of Instream Habitat: Pilot Study using Ground-based LiDaR in Logan River Watershed, Ecogeomorphology and Topographic Analysis Lab, Utah State University, Prepared for US Forest Service, Logan, Utah, 28 pp.
- Lokteff RL*, Roper B & Wheaton JM. In Review. Trout Passage of
Beaver Dams in Two Northern Utah Tributaries. submitted to Transactions
of American Fisheries Society.
- NCALM LiDaR of Temple Fork Watershed: LiDAR data acquisition and processing completed by the National Center for Airborne Laser Mapping (NCALM - http://www.ncalm.org). NCALM funding provided by NSF's Division of Earth Sciences, Instrumentation and Facilities Program. EAR-1043051.DOI: 10.5069/G9HQ3WTG