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The effect of stream restoration on preferred cutthroat trout habitat in the Strawberry River, Utah. Nic Braithwaite. Introduction – Strawberry River. http://www.merriam-webster.com/cgi-bin/nytmaps.pl?utah. Strawberry River. Major tributary to Strawberry Reservoir
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The effect of stream restoration on preferred cutthroat trout habitat in the Strawberry River, Utah Nic Braithwaite
Introduction – Strawberry River http://www.merriam-webster.com/cgi-bin/nytmaps.pl?utah
Strawberry River • Major tributary to Strawberry Reservoir • Harmful water use and land management practices degraded habitat • Limited cutthroat trout spawning, rearing, and resident stream populations
Strawberry River • Utah Division of Wildlife Resources (UDWR) recently completed a stream restoration project on the Strawberry River. • Active restoration primarily included bank stabilization and revegetation efforts. • UDWR Goals and Objectives: Reduce TP and increase the quality of fish habitat.
Major Project Questions • Have the restoration efforts increased the amount of suitable spawning habitat? • Have the restoration efforts increased the amount of suitable habitat for juvenile and adult life stages in the river?
Project Site – Four 500m Reaches Kilometer 0 0.75 1.25
Main Habitat Variables • Depth • Near-bed velocity • Substrate • Cover • Habitat type • Temperature (UDWR)
Electrofishing Surveys • 3-pass depletion • 100 m sub-reaches • Focus is on the cutthroat trout population and length distributions
Redd Surveys – Preference • Shallower depths (0.15 – 0.30 m) • Higher near-bed velocities (0.15 – 0.50 m/s) • Moderate substrate (22 – 64 mm) • Riffle habitat type
Electrofishing Surveys – Size Class Dist. Number of Bear Lake Cutthroat Trout Size Class (mm)
Snorkel Surveys – Preference • Deeper water (> 0.40 m) • Presence of cover • Pool habitat type
Snorkel Surveys – Reach Scale Habitat “Restored ‘09” Study Reach “Control 1” Study Reach
Summary/Conclusions • Restoration may have lead to more desirable habitat for some spawning variables • Improvements may not be ecologically significant • Cutthroat trout densities higher in restored reaches. Fish may be redistributing themselves, but not increasing in abundance • Size distribution of cutthroat trout was very similar throughout restored and unrestored reaches
Summary/Conclusions • Restoration tended to increase pools and number of habitat units per reach, but not an overall increase in depth or cover • Difficult to assess the impact of restoration on available habitat • Continued monitoring can help tease out sources of variation, as well as capture long-term responses
Acknowledgements Utah State University: Chris Luecke (Advisor) Scott Miller (Committee Member) Michelle Baker (Committee Member) Nira Salant (Post-Doc WATS) Utah Division of Wildlife Resources: Alan Ward (Strawberry Project Leader) Justin Robinson (Strawberry Project Biologist)