More than 125 planners and scientists gathered for a May 20th forum focusing on the latest scientific studies of shoreline armoring in Puget Sound. A video of forum presentations is now available online (below).

“Armoring” refers to hardened structures designed to protect shorelines against natural processes like erosion and storm surge, and it is common throughout the region. Almost 30% of the Puget Sound shoreline—about 700 miles total—is now classified as armored, and the figure grows by a mile or more per year.

Scientists have been wondering for some time how this trend is affecting the ecology of Puget Sound, and the Puget Sound Partnership has made reduction of shoreline armoring one of the centerpieces of its recovery efforts. Studies are increasingly pointing to armoring’s negative effects, but the science has not always been definitive. That was the motivation behind the recent Salish Sea Shoreline Forum at South Seattle Community College where scientists and planners gathered to discuss their research.

Salish Sea Nearshore Conference #3 from Salish Sea Shoreline Forum Video on Vimeo.

Forum highlights included a presentation by University of Washington’s Megan Dethier who described a recent study of more than 60 Puget Sound beaches. Although not yet peer-reviewed, her preliminary results showed that, among other things, beaches with armoring showed less biological diversity. She found that:

• Crows love armored beaches, but varieties of other birds declined.
• Birds at armored beaches perched more and foraged less, a possible sign of less available food.
• There were noticeably more invertebrates at unarmored beaches, something that affects the entire food web, from forage fish to keystone species—Dethier pointed out seeing bears dining on tiny amphipods known as “beach hoppers.”
• Unarmored beaches are wider and shadier, and have more organic debris.

A report describing the entire forum is expected to be released by forum organizers in the coming months. The forum was sponsored by The Washington State Department of Natural Resources, the Washington Department of Fish and Wildlife, the Puget Sound Partnership, Futurewise and Washington Sea Grant.