By SUSIE KALHORN
Puget Sound needs saving, and it’s now more apparent than ever that what shoreline homeowners do on their own stretch of beach can play an important role in the sound’s health.
Recent efforts to improve the health of Puget Sound have focused on the nearshore, the place where the land meets the sea. It’s called the sound’s breadbasket because it is so productive. When we explore the beach at low tide, it’s teeming with life: barnacles, kelp crabs, moon snails, a plethora of eggs stuck to eelgrass. Less obvious is how important the desert-looking sand and gravel flats are to small fish like the sand lance and surf smelt, which lay their eggs high up on the beach during high tide. When the tide recedes, the eggs are protected from drying out by the shade of shoreline trees and shrubs.
These little fish called forage fish feed bigger fish like threatened chinook salmon, which are the primary food of the threatened southern resident orcas. When orcas come to our shores, people crowd the beach at Point Robinson in awe. The reality, however, is pretty simple: No little fish means no salmon, which means no orcas.
We know that bulkheads and groins, which are referred to as shoreline armoring and are common on Vashon, can change the beach. Bulkheads protect the land from washing away, but they also disconnect the land from the sea. Sand and gravel move along the shore, pushed by currents, tides and waves. The sands and gravels that have moved elsewhere are normally replenished by eroding bluffs. Shoreline armoring, however, can starve the beach, changing it and the community of organisms that can survive there. In recent years much research has gone into identifying these “feeder bluffs” and tracking “drift cells,” the direction the sand and gravel travels and where it is deposited. King County, for example, has worked hard to protect feeder bluffs on the southeast side of Maury Island at Piner Point so that sand and gravel can continue to make it all the way up to Point Robinson.
Dr. Megan Dethier at the University of Washington is currently studying 34 matched pairs of armored and unarmored beaches in Puget Sound. She’s found that armored beaches are 4 to 9 meters narrower than natural beaches and have 20 to 60 percent less shade, making life difficult for forage fish egg survival. The accumulation of wrack — the seaweed and other bits left at high tide — is also much greater on natural beaches. This wrack, in turn, supports small animals like beach hoppers, which are food for fish and shorebirds. Dethier found 15 times more crustaceans on unarmored beaches than armored beaches.
“It’s the stinkin’ seaweed and the critters that feed the food web that is disrupted by armoring,” she said at a recent conference.
I was dismayed to read a recent report put out by King County on change to the shorelines on Vashon-Maury and in the surrounding area. Researchers did an inventory to see what human-made changes had occurred along the shoreline between 2004 and 2013 on the 96 miles of Water Resources Inventory Area 9 (WRIA 9) shoreline. WRIA 9 extends from Federal Way to the north side of Elliot Bay and includes all of Vashon-Maury Island. The distressing results: “The amount of new shoreline armoring found through the course of this study offset all of the gains from shoreline restoration projects over the past 8 years.”
I’m concerned about the habitat that supports Puget Sound’s food web. Our tax dollars dedicated to restore Puget Sound will be wasted if we continue to let habitat destruction outpace habitat restoration. It’s like we’re on a treadmill, expending dollars and getting nowhere.
Most of the new bulkheads or major bulkhead repairs, clearing in the shoreline buffer, new docks, groins, stairs and ramps occurred on Vashon-Maury and most were unpermitted. The longest new bulkhead in WRIA 9 is an unpermitted 292-foot structure located at the very beginning of a drift cell at the mouth of Quartermaster Harbor.
I know that island shoreline homeowners care passionately about Puget Sound. I’m not advocating that we tear out all existing bulkheads and let our shorefront homes wash out to sea. I am suggesting we be very cautious about installing new bulkheads and clearing brush along the shoreline. Forage fish need the sand and gravel and the shade. Views and slope stability can be maintained using judicious pruning instead of clearing, thereby protecting human life and safety. Think Oso. We know much more about nearshore ecology than we did when our island was simply a summer beach playground for mainlanders.
There are engineer-ecologists that can help determine whether a bulkhead is really necessary at a shoreline property, and a workshop this weekend will help homeowners explore what they can do to keep a more natural beach at their property. Although getting construction permits has not been the Vashon way, we are missing opportunities, such as exploring alternatives to new bulkheads, setting bulkheads back from the ordinary high water mark and avoiding putting armoring on top of forage fish spawning areas.
Puget Sound is our moat. It is what defines us as islanders. As a community, we need to decide how we are going to protect and restore our magnificent piece of it for generations to come.
— Susie Kalhorn is an environmental educator.
Homeowners workshop
On Saturday the King Conservation District will put on a free workshop for shoreline and bluff homeowners to learn the best practices for protecting property while also protecting Puget Sound. For more information, see the classes section of this week’s calendar on page 8.
