Puget Sound Shorelines Hit The Wall

Apr 22, 2016

Walls are going up around Puget Sound, and the sound is paying for it. In King County, property owners have walled off most of the shoreline with concrete bulkheads and other heavy infrastructure. A new study suggests the practice known as shoreline armoring is more harmful to Puget Sound than previously thought.

Aimee Kinney is a biologist at the University of Washington Tacoma.

"I see lots of little sand fleas jumping around, do you see those?" Kinney said.

Most of Alki Beach is a city park. A concrete seawall separates the popular beach from the road and buildings above it. But this little stretch of beach below a waterfront house has logs, driftwood, and some kelp and eelgrass piled up at the high-tide line. It's a more natural shoreline, and the sand fleas like it there.

"So this is a really important food source for salmon coming out of the rivers to bulk up on before they go out in the ocean," Kinney said.

Beaches that haven't been walled off by concrete or rock piles are an increasingly rare commodity in Puget Sound.

"These beaches are critical for salmon," Kinney said.

In all, Puget Sound loses nearly a mile of shoreline to armoring every year. The damage stretches beyond that walled-off mile. A new study by University of Washington researchers says a new seawall can damage the shoreline habitat of neighboring areas.

Megan Dethier with UW's Friday Harbor Labs is the lead author on that study.

"Of course, that all adds up to Puget Sound wide or Salish Sea wide," Deithier said, "So it's not just you and your neighbors, it's the whole broad ecosystem."

Researchers and local officials say homeowners often armor their shorelines illegally, but local governments lack the ability to enforce their shoreline regulations.

These conflicts are likely to get worse as sea levels rise with our changing climate and more waterfront owners try to protect their properties from the rising seas.

Copyright 2016 KUOW