Event Title

Concurrent Sessions B: Lamprey Passage - From Altered to Free-Flowing; Migration Patterns of Adult Pacific Lamprey In A "Free-Flowing" River Environment Above Lower Gran

Location

Agriculture Production Theater, Oregon State University

Start Date

25-6-2013 10:40 AM

End Date

25-6-2013 11:00 AM

Description

Complex life histories render anadromous fish susceptible to environmental and anthropogenic change. Adult Pacific lamprey (Lampetra tridentata) returning to the Snake River, ID must ascend a series of eight dams within the Columbia River hydrosystem resulting in prolonged exposure to an altered passage environment. While some research has focused on improving passage at these facilities, little is known about adult behavior and distribution patterns within free-flowing river environments. In this study, radiotelemetry was used to monitor behavior, migration timing, and movement patterns of upstream migrating adult lamprey through the Snake River basin upstream of Lower Granite Dam. To determine seasonal timing, migration rates, overwintering habitat, and final distributions, telemetry data of individually radio-tagged adults were evaluated. Additionally, adult behavior in relation to environmental variables was analyzed to determine which factors were correlated with overall movement patterns. From 2006 to 2009, the movements of 146 radio-tagged fish were recorded. Adults were detected throughout much of the Snake and Clearwater drainages but returns to the Clearwater River were higher in all years (annual estimates = 61.2-70.3%). Fish moved into the upper reaches of the South Fork Clearwater, Lochsa, Selway, and Salmon Rivers as far as 945 rkm from the Pacific Ocean. From August to October, radio-tagged adults encountered river temperatures at the Snake-Clearwater confluence that differed by approximately 10°C. Migration rates were assessed for 93 radio-tagged adults through 15 reaches. Median migration rates were more variable in reservoir reaches (annual range =0.1-41.1 km•day-1) and faster than in free-flowing reaches (mean = 12.1 km•day1). General migration behavior and stream selection were not strongly associated with environmental variables. Overall these results suggest that current free-flowing environments may provide adequate migration conditions and that adult Pacific lamprey have the capacity to reach spawning streams after navigating the altered Columbia River hydrosystem.

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Jun 25th, 10:40 AM Jun 25th, 11:00 AM

Concurrent Sessions B: Lamprey Passage - From Altered to Free-Flowing; Migration Patterns of Adult Pacific Lamprey In A "Free-Flowing" River Environment Above Lower Gran

Agriculture Production Theater, Oregon State University

Complex life histories render anadromous fish susceptible to environmental and anthropogenic change. Adult Pacific lamprey (Lampetra tridentata) returning to the Snake River, ID must ascend a series of eight dams within the Columbia River hydrosystem resulting in prolonged exposure to an altered passage environment. While some research has focused on improving passage at these facilities, little is known about adult behavior and distribution patterns within free-flowing river environments. In this study, radiotelemetry was used to monitor behavior, migration timing, and movement patterns of upstream migrating adult lamprey through the Snake River basin upstream of Lower Granite Dam. To determine seasonal timing, migration rates, overwintering habitat, and final distributions, telemetry data of individually radio-tagged adults were evaluated. Additionally, adult behavior in relation to environmental variables was analyzed to determine which factors were correlated with overall movement patterns. From 2006 to 2009, the movements of 146 radio-tagged fish were recorded. Adults were detected throughout much of the Snake and Clearwater drainages but returns to the Clearwater River were higher in all years (annual estimates = 61.2-70.3%). Fish moved into the upper reaches of the South Fork Clearwater, Lochsa, Selway, and Salmon Rivers as far as 945 rkm from the Pacific Ocean. From August to October, radio-tagged adults encountered river temperatures at the Snake-Clearwater confluence that differed by approximately 10°C. Migration rates were assessed for 93 radio-tagged adults through 15 reaches. Median migration rates were more variable in reservoir reaches (annual range =0.1-41.1 km•day-1) and faster than in free-flowing reaches (mean = 12.1 km•day1). General migration behavior and stream selection were not strongly associated with environmental variables. Overall these results suggest that current free-flowing environments may provide adequate migration conditions and that adult Pacific lamprey have the capacity to reach spawning streams after navigating the altered Columbia River hydrosystem.