Food web impacts of geoduck clam aquaculture practices in Puget Sound, Washington

Abstract

Aquaculture operations are a frequent and prominent cause of anthropogenic disturbance to marine and estuarine communities. In Puget Sound, Washington, aquaculture of the Pacific geoduck clam (<italic>Panopea generosa</italic>) is on the rise, however little is currently known about impacts of the industry on ecological communities. The study took place during the initial, structured phase of intertidal geoduck aquaculture, when nets and PVC tubes were in place to protect immature geoducks from predators. The food web of a local ubiquitous consumer, Pacific staghorn sculpin (<italic>Leptocottus armatus</italic>), was compared between geoduck aquaculture sites and nearby reference areas without aquaculture. A variety of research techniques, including stomach content analysis, stable isotope analysis and bioenergetics modeling, were utilized to examine the ecological impacts of geoduck aquaculture at its current scale. Overall, the results showed that the structured phase of geoduck aquaculture initiated some changes to staghorn sculpin ecology, but the general function of sculpin within the food web remained unchanged.