Project Title

Understanding of the Influence of Non-indigenous Smooth Cordgrass (Spartina alterniflora) on Food Web Dynamics in Pacific Northwest estuaries

Description

The primary objective of this project is to determine the importance of cordgrass production to the detritus-based food webs in Willapa Bay. The research seeks to answer:

• What are the potential changes imposed on Pacific Northwest estuarine food webs by smooth cordgrass?
• Do Pacific oysters (Crassostrea gigas) make use of organic matter derived from smooth cordgrass in Pacific Northwest estuaries?

Worldwide, non-indigenous species are considered one of the top threats to the world's ecosystems. Rivaled only by the impact of habitat loss and alteration, this global threat has been used to justify a massive eradication campaign against three species of non-indigenous cordgrass in Pacific Northwest estuaries. Spartina alterniflora is the most widespread of these species, particularly in Willapa Bay, WA. This species of cordgrass has brought about a tremendous increase in productivity in the system, but many believe it is destructive to habitat and wildlife (including juvenile Pacific salmon), and a threat to the local economy which is founded largely on harvest of oysters and other marine resources.

This project examines the production base of oysters in Willapa Bay and in nearby Grays Harbor, where S. alterniflora is absent. Measuring naturally occurring stable isotope ratios in adult and post-settled larval oysters and in several organic matter sources, including S. alterniflora, eelgrasses (Zostera spp.), benthic algae and seston. This project will determine the importance of S. alterniflora as a food source for oysters. This project will also provide the foundation for further research on how S. alterniflora production relates to other commercially important species (e.g., Dungeness crab, Cancer magister) and to juvenile Pacific salmon (Oncorhynchus spp.).

Investigators

Blake Feist, Chris Harvey (Fisheries Resources Analysis and Monitoring Division), Bill Reichert

Collaborators

Jennifer Ruesink, Alan Trimble, Charles Simenstad (University of Washington), and Richard Hicks (Conservation Biology Division)

Support

NOAA Fisheries

Project Status

Data analyses ongoing, one manuscript in review

Watershed Home  |  Landscape Ecology and Recovery Science team page