Skokomish Tribe Removes Invasive Varnish Clams, Restores Shellfish Beds

The Skokomish Indian Tribe removed thousands of pounds of varnish clams, an invasive species, from the Skokomish Estuary tidelands this summer.

A varnish clam looks similar to a manila clam but the giveaway is the peeling brown film on the shell, like old furniture. The non-native clam from Japan showed up on the West Coast in the early 1990s and is found throughout Hood Canal.

“There are so many varnish clams here, we’re trying to figure out if we can create a bait or consumption market for them,” said Blair Paul, the tribe’s shellfish biologist. The tribe had not harvested them prior to this project but by this fall the tribe had found a small consumption market for them, with weekly demands up to 2,000 pounds.

The project is part of a larger effort to improve the shellfish habitat, after shellfish beds on the tidelands were damaged by upstream land use in the watershed.

Historic logging practices, hydropower projects, agriculture and transportation activity, plus the construction of dikes and levees, had significantly altered the river’s natural processes for decades, including sediment recruitment and transport.

As a result, the tidelands were starved of coarse sediment and were being smothered by fine sediment. To remedy this, 1,000 cubic yards of gravel were spread on the tidelands this summer.

To support the shellfish population, the tribe will spread Pacific oyster cultch (shells) and clam seed on the tidelands each spring for the next three years. Ultimately, about 13 acres of Manila clam habitat and 15 acres of oyster habitat will be added.

Technical assistance is being provided by the Puget Sound Restoration Fund for the gravel enrichment and shellfish seeding project, with funding through mitigation funds from Naval Base Kitsap.

Photo: Skokomish tribal members harvest varnish clams as part of the effort to remove the invasive clams from the Skokomish Estuary tidelands. T. Royal