Every salmon migrating to and from Lake Washington and its tributaries must pass through the Ship Canal twice in its life. Each summer, water temperatures can reach lethal levels for salmon. This can delay migration, increase disease risks and even kill fish directly. Addressing this problem is a crucial step to save imperiled salmon runs and bring tribal and recreational salmon fishing back to our urban Seattle corridor. LLTK has started working with local watershed managers and other partners to create a suite of science-based alternatives to address the ship canal water temperature problem. These alternatives will then be assessed, and a solution developed. This work is made possible by a grant from King County.
The Hood Canal Bridge is a migration barrier and death trap where predators lurk for easy pickings. Up to 50% of the steelhead that make it to the bridge don’t make it past, and we expect the bridge is impacting other salmon. While over the long run we need to work towards a more fish-friendly bridge design, LLTK and our partners have assessed the bridge and secured funding to design temporary solutions to reduce fish mortality at the bridge. This includes an underwater guidance structure designed to encourage fish to swim to where there are no pontoons blocking their migration route. However, state- wide budget reductions may make it difficult to secure the $2-3 million necessary to get solutions in the water.
Degraded habitat, past overharvest, production-oriented hatchery practices, and a changing ecosystem have all reduced diversity in our salmon and steelhead populations. With climate change bearing down, rebuilding this lost diversity is key to creating the resilience our fish need to survive.
We recognize it will take every tool available to keep salmon in our waters now, and in the future. LLTK and our partners are testing new hatchery strategies that foster diversity with the goal of returning more and larger fish, and we’re helping to restore habitat that promotes diversity, like estuaries that are critical to juvenile wild Chinook.