An introduction to in-water, seawall habitat
Elliott Bay Seawall: An important salmon migration corridor
Tens of thousands of salmon migrate along the Elliott Bay Seawall and then up the Green/Duwamish River and its tributaries every year to spawn. After beginning their lives in freshwater rivers, juvenile salmon then swim down the Green/Duwamish River to enter Elliott Bay in the spring and summer – along the Elliott Bay Seawall. Because the Elliott Bay Seawall Project area is such an important link in the salmon migratory route, improving salmon habitat within Elliott Bay is pivotal to the success of regional salmon recovery.
Historically, the eastern shoreline of Elliott Bay looked much like other unaltered shorelines across Puget Sound—a bluff-backed beach with intertidal marshes and mudflats. The mudflats and gently sloping beaches of Elliott Bay were home to a bounty of birds, fish, and marine invertebrates.
When the seawall was built, the nearshore was cleared to make room for piers, roads, and buildings. With the lack of typical nearshore habitat, salmon migrating along the waterfront can become confused and vulnerable to predators. Current challenges that juvenile salmon encounter along the seawall include:
Despite these challenging aspects, today’s seawall still provides a home to many species of aquatic life.
As part of the seawall replacement program, the City of Seattle is committed to restoring a functional salmon migration corridor along Seattle’s waterfront. The Elliott Bay Seawall Project has been researching how best aquatic habitat can be restored.
Since 2008, four major studies have been conducted along Seattle’s waterfront:
Habitat restoration along Seattle’s seawall
To make life better for juvenile salmonids and other marine creatures, the City is designing a shallow, lighted migratory corridor along the seawall to enhance habitat for juvenile salmon and other marine life. The City is planning to restore habitat by: