Molluscs in the Class Bivalvia feed on phytoplankton and detrital particles suspended in the water column, serving as a key trophic link between microscopic primary producers and higher consumers. Epibenthic bivalves can function as ecosystem engineers through the provision of hard substrate and three-dimensional biogenic structure, while infaunal bivalves can function as engineers through physical alteration of soft substrate habitats. Numerous native and non-native species of bivalves occur in Puget Sound, including important aquaculture species such as Pacific oysters (Crassostrea gigas), non-native invasive species such as the purple varnish clam (Nutallia obscurata), and species targeted in recreational fisheries (e.g., nativelittleneck clams and non-native Manila clams). The native geoduck clam, Panopea generosa, is valued as a commercially-fished species and as an aquaculture species. The native Olympia oyster, Ostrea lurida (also known as Ostreola conchaphila) currently is a restoration target in Puget Sound, having been depleted through human activities in the last century.
Invasive species are considered a top threat to the balance of ecosystems worldwide. New discoveries of non-native green crabs in Puget Sound have highlighted that concern here at home, but invasive species can impact more than just the food web. Some introduced species can produce toxins that accumulate in shellfish or by directly infecting the human body.
Social scientists around the Salish Sea are predicting the effects of environmental change through the lens of culturally important foods.
Environmental samplers may provide early detection of harmful algal blooms (HABs) in Puget Sound. This toxic algae is expected to increase as the climate changes, bringing with it new and potentially more severe outbreaks of shellfish poisonings.
A 2005 report from the Washington Sea Grant Program describing the history and current state of native Olympia oysters including their ecology, history with human interactions, prefered habitat, and reestablishment efforts in the Puget Sound region.
This 2006 technical report for the Puget Sound Nearshore Partnership describes how shellfish have high ecological, economical, cultural, recreational value, however human activity is threatening their existence by altering their native habitat with changes in land use, shoreline modifications, stormwater, sewage and industrial discharge.
Northwest Coast First Peoples made clam garden terraces to expand ideal clam habitat at tidal heights that provided optimal conditions for clam growth and survival, therefore enhancing food production and increasing food security.
A November 2013 literature review by Washingtom Sea Grant synthesizes the state of the science of geoduck clams and the potential environmental impacts of geoduck aquaculture in the Puget Sound region.