By The Herald Editorial Board
Instead of hiking boots and dog paws, more of the Snohomish River delta’s Spencer Island could soon be traversed by chinook salmon smolts.
The state Department of Fish and Wildlife, Snohomish County and the U.S. Army Corps of Engineers have proposed breaching and lowering dikes on the 414-acre island as part of a plan to return to the estuary what was first diked and built up as grazing and agricultural land in the early 1900s. The project would restore important habitat for chinook salmon and other wildlife, as reported Saturday by The Herald’s Ta’Leah Van Sistine.
What’s left to be determined, following the closing of a public comment period on Oct. 8, is how much will be returned to the fish and how much will be left accessible to people.
Located east of I-5 and north of the U.S. 2 trestle between Steamboat and Union sloughs, the island is split between state land to the north, where hunters and dog walkers are allowed; and county property to the south, where hikers and birdwatchers tread.
In truth, the reclamation by river and tidal waters had already begun, although unplanned, when a dike failed on the northern portion of the island in 2005; allowing portions of the island to be inundated as tides flow and ebb. Work to lower and remove dikes as proposed — a $9 million project — would further expand the estuary and the amount of habitat, giving over to salmon up to more than double the current area of available habitat.
The habitat restoration follows similar projects in the Snohomish River estuary, including a 2019 project on Mid-Spencer Island, north of the proposed restoration, and last year’s joint project between the Tulalip Tribes and the Port of Everett to remove dikes that restored 353 acres to the Blue Heron Slough, part of 1,000 acres of estuary restoration work at Smith Island and the Qwuloolt marsh.
Over the last century, the Snohomish River estuary — the twisting channels that cut through marshlands as the river connects with Port Gardner Bay, Possession Sound and the rest of the Salish Sea — lost about 85 percent of its vital habitat to diking and land conversion. The diking created dry land for agriculture but at the cost of habitat for up to 1.6 million chinook salmon smolts annually, according to a 2020 watershed report by the Treaty Tribes of Western Washington.
Since 1984, when the Pacific Salmon Commission began tracking salmon abundance, Salish Sea chinook salmon populations — deemed “threatened” under the Endangered Species Act — have declined 60 percent, according to the Environmental Protection Agency. In more recent years, the number of adult salmon returning to spawning grounds has seen a modest decrease, said the agency responsible for threatened and endangered species protection.
Marshland estuaries produce large amounts of insects on which salmon smolts — the young salmon that are making the transition from freshwater to saltwater — feed and grow before entering the ocean. The more habitat for smolts, the more smolts there are and the larger and healthier they become and the better they are able to survive life at sea, in order to return to spawn and continue the cycle. Studies have found, according to SalmonRecovery.gov, that faster growing and larger juvenile chinook salmon are better positioned to survive their first year in the ocean, when most salmon are believed to perish.
And more salmon means a more robust food web for other wildlife, including other fish, orcas and other marine mammals, and bald eagles, ospreys and other birds; as well as more salmon for sports fishing and commercial fishing and for Tribes, honoring treaty commitments.
But, in the case of Spencer Island, that habitat restoration could come at the cost of access for birdwatchers, walkers and waterfowl hunters. Of nine alternative proposals up for consideration, all could potentially limit up to 5 miles of trails on the island, including a loop trail on the county’s southern end of the island and a trail to the north that follows Steamboat Slough. Seven of the plans would keep access to all or most of the loop trail, while four would also preserve access to at least some of the Steamboat Slough trail.
But even then, some access may be limited.
“If folks wanted to off-road with waders, they could,” Seth Ballhorn, with state Fish and Wildlife, told The Herald, but “the county wouldn’t be maintaining that as a formal trail.”
As important as it is to restore as much fish habitat as possible, there’s reason to preserve some access for people. The birdwatchers, hunters and others who visit the island can and have been stewards of the marshland and estuary there, with interests in their continued protection. And as estuary is restored, the island’s potential to serve as an environmental lab for the county’s students also grows, providing lessons in ecology and nature’s resilience that children and young adults can see with their own eyes.
As well it would provide proof of the value of such restoration efforts for the entire Snohomish River delta.
Spencer Island could serve as a window for all to view and better understand the importance of estuaries and habitat, not just for salmon, but for all wildlife. And for us.
Learn more and comment
To review proposals for the Spencer Island habitat restoration, go to the state Department of Fish and Wildlife’s Spencer Island page at tinyurl.com/SpencerWDFW. To comment, go to tinyurl.com/SpencerFeedback