Aquatic Resources

Prospect 3 Fish Screen and Ladder Biological Evaluation

Meridian designed, fabricated, and installed a remote PIT-tag detection system in the Prospect No. 3 Hydroelectric Project fish ladder. Four individual PIT-tag antennas were continuously monitored using an Oregon RFID half duplex multiplexer-reader. Meridian PIT-tagged resident trout and introduced them into the ladder to document upstream fish passage success and timing. Meridian also conducted a mark-recapture test to determine fish entrainment and injury rate through the project intake fish screens and fish bypass system, and used PIT-tagged fish to measure fish screen bypass travel time.

Estimation of Fish Entrainment at Lake Kachess and Keechelus Dams

US Bureau of Reclamation
Meridian designed and conducted fish entrainment studies at the outlets of Lake Keechelus and Lake Kachess dams over a 2-year period, focused primarily on evaluating bull trout entrainment. Meridian employed a screw trap and hydroacoustic technology to measure continuous fish entrainment rates over the 4-month survey period at Lake Keechelus. At Lake Kachess, Meridian used a screw trap and experimental fyke net trap to measure fish entrainment rates. Meridian custom-designed and built the experimental fyke net and screw trap cable rigging system to ensure that these structures would remain in place and perform effectively throughout the 4-month survey period.

Yale Tailrace Water Quality Attainment Study

Meridian conducted a detailed assessment of the fish assemblage and water temperature regime of the Lake Merwin Canyon, which is influenced by discharge from the Yale Project powerhouse. Meridian quantified seasonal and diel fish assemblage and distribution by depth using tangle-netting and boat electrofishing. Meridian measured water temperature patterns by anchoring four vertical thermistor strings in strategic locations. Meridian analyzed the detailed fish presence and water temperature data and related this to discharge from the Yale Hydroelectric Project. Fish presence was related to water temperature by depth and reach. Water temperature data was related to project generation and identified correlation between maximum water temperature, temperature fluctuation and project generation/discharge. Meridian made recommendations on operation changes to increase cold water habitat availability for cold water aquatic biota.

Bull Trout Limiting Factors Analysis

PacifiCorp Energy
Meridian designed and conducted a limiting factors analysis of bull trout in tributaries to Lake Merwin and Swift Creek Reservoir. We developed a set of physical habitat criteria for each life stage, and collected fish presence, water temperature, and habitat data to rate 16 streams based on these criteria. The Qualitative Habitat Assessment (QHA) method was applied to define limiting factors by life stage for each stream. Results of QHA were used to rank streams for potential bull trout restoration.

North Umpqua Hydroelectric Project Fish Passage Facility Evaluation

Meridian is leading a hydraulic and biological evaluation of the new Soda Springs Dam fish passage facilities (upstream fish ladder and downstream fish screens) at the North Umpqua Hydroelectric Project. Meridian biologists are using videography to describe fish behavior (with emphasis on adult steelhead and spring Chinook salmon), identifying areas of the ladder that may inhibit passage, and evaluating fish injury and mortality rates associated with passage of downstream migrating juvenile spring Chinook salmon through the fish screen. Meridian is also conducting an underwater videography evaluation of the Soda Springs and Slide Creek tailrace barriers to determine if they pose a risk of injury to adult anadromous salmonids.

Resident Trout Limiting Factors Analysis

Public Utility District No. 1 of Snohomish County
In cooperation with the University of Washington, Meridian biologists designed and conducted field studies for a resident trout limiting factors analysis in Spada Lake, collecting and integrating data on the fish species assemblage; the size, parasite load, and abundance of trout and brown bullhead; and fish forage base (zooplankton and neuston) distribution and abundance.

Downstream Migrant Transport Flow Evaluation

Tacoma Power
Using radio telemetry, Meridian biologists assessed the migration rates and survival of salmon and steelhead smolts as they moved through the lower 50 miles of the mainstem Cowlitz River. The effects of pulsed flows on the migration timing of each species were determined. We conducted all aspects of the study, including design, setup and maintenance of the telemetry arrays; radio tagging hatchery and naturally produced coho, Chinook and steelhead; mobile tracking; and data analysis and reporting.