Session Title

Session S-06F: Elwah River Restoration: Evolution of Habitats and Ecosystems During a Dam Removal Project

Conference Track

Restoration

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Start Date

1-5-2014 1:30 PM

End Date

1-5-2014 3:00 PM

Abstract

The removal of the Elwha and Glines Canyon Dams on the Elwha River will renew access for anadromous salmonids to 70 miles of high quality habitat located primarily within Olympic National Park. Concurrent dam removals began in 2011, with complete fish passage projected in 2014. While the long-term benefits to anadromous populations are undisputed, release of stored sediment behind the dams is temporarily elevating suspended solids and degrading existing spawning habitat downstream of the Elwha dam. To minimize deleterious effects in the lower river, give populations an early opportunity to spawn and imprint on upstream habitats, and examine the response of anadromous fish to the newly available areas, Chinook and coho salmon and steelhead were moved upstream of Elwha and Glines Canyon dams in 2011 and 2012. We radiotagged and tracked 20 adult Chinook salmon, 47 adult coho salmon, and 37 steelhead to determine spatial and temporal movements and spawning in tributaries and the main stem river. An additional 10 coho and 1 chum salmon were tagged in the lower river and released to continue their migration. Fish movements were monitored using fixed sites and mobile tracking. We also observed substantial volitional fallback and subsequent spawning or migrational movement in the lower river by all both Chinook and coho salmon. Kelting behavior was common in tagged steelhead. We observed coho salmon and steelhead redds in Little River, Indian Creek, the mainstem Elwha River, and side channels of the river. Two Chinook redds were seen in the area upstream of Glines Canyon Dam. Tributaries seeded with adults retained spawers while mainstem releases provided for more exploratory migrational movements. The offspring from these relocated adults will have direct outmigration access to the ocean and the river will be open for upstream migration when they return as adults. Transplanting adult salmonids is labor intensive and requires source populations from downstream for seeding, but can result in spawning activity in new areas and can be managed to include hatchery and wild fish to supplement naturally occurring colonizations.

Rights

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Language

English

Format

application/pdf

Type

Text

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May 1st, 1:30 PM May 1st, 3:00 PM

Movement of transplanted adult salmonids in previously inaccessible habitat in the Elwha River

Room 602-603

The removal of the Elwha and Glines Canyon Dams on the Elwha River will renew access for anadromous salmonids to 70 miles of high quality habitat located primarily within Olympic National Park. Concurrent dam removals began in 2011, with complete fish passage projected in 2014. While the long-term benefits to anadromous populations are undisputed, release of stored sediment behind the dams is temporarily elevating suspended solids and degrading existing spawning habitat downstream of the Elwha dam. To minimize deleterious effects in the lower river, give populations an early opportunity to spawn and imprint on upstream habitats, and examine the response of anadromous fish to the newly available areas, Chinook and coho salmon and steelhead were moved upstream of Elwha and Glines Canyon dams in 2011 and 2012. We radiotagged and tracked 20 adult Chinook salmon, 47 adult coho salmon, and 37 steelhead to determine spatial and temporal movements and spawning in tributaries and the main stem river. An additional 10 coho and 1 chum salmon were tagged in the lower river and released to continue their migration. Fish movements were monitored using fixed sites and mobile tracking. We also observed substantial volitional fallback and subsequent spawning or migrational movement in the lower river by all both Chinook and coho salmon. Kelting behavior was common in tagged steelhead. We observed coho salmon and steelhead redds in Little River, Indian Creek, the mainstem Elwha River, and side channels of the river. Two Chinook redds were seen in the area upstream of Glines Canyon Dam. Tributaries seeded with adults retained spawers while mainstem releases provided for more exploratory migrational movements. The offspring from these relocated adults will have direct outmigration access to the ocean and the river will be open for upstream migration when they return as adults. Transplanting adult salmonids is labor intensive and requires source populations from downstream for seeding, but can result in spawning activity in new areas and can be managed to include hatchery and wild fish to supplement naturally occurring colonizations.