Washington Coast Shellfish Aquaculture Study

Willapa Bay and Grays Harbor are known for their ecological integrity, habitat values and water quality despite historic alterations to the bays and their watersheds. They are tremendously important to the conservation of fish, shorebirds and other wildlife; and they are economically important to fisheries, shellfish aquaculture and as transportation waterways. Like other estuaries on the West Coast, they are complex and dynamic ecosystems affected by variability and trends in ocean conditions and climate.

The complexity of these ecosystems makes shellfish aquaculture and resource management in the bays more challenging. Sustaining shellfish aquaculture is a high priority concern for the state of Washington and communities in Pacific and Grays Harbor Counties. The Washington Coast Shellfish Aquaculture Study is one of several coordinated efforts to address this concern.

The Challenges

Among the principle issues challenging aquaculture in coastal Washington are how shellfish farms interact with two species: eelgrass and burrowing shrimp. Eelgrass beds provide important habitat to many protected and managed species. Shellfish farming practices are evolving rapidly, and further study is needed to fully understand the relationship between farming practices and eelgrass.

High population densities of burrowing shrimp can soften mudflats and cause shellfish to sink and suffocate. Many techniques have been tested for controlling the shrimp on shellfish farms, but without chemical controls, growers still lack an effective approach for managing them. Shellfish farmers need economically and ecologically sustainable approaches to address the issues related to both eelgrass and burrowing shrimp.

The Study

The Washington Coast Shellfish Aquaculture Study is a three-year applied research project to assist planning and collaboration amongst tideland managers, owners and regulators in Willapa Bay and Grays Harbor. The goal is to sustain shellfish aquaculture in the two bays by establishing a collaborative ecosystem-based management* framework that will highlight potential solutions to the current challenges and support ongoing participation from tideland managers, owners and regulators.

* ecosystem-based management is an environmental management approach that recognizes the full array of interactions within an ecosystem, including humans, rather than considering single issues, species, or ecosystem services in isolation.

The Project Team and Working Group

The project team is led by Washington Sea Grant with participation from collaborating scientists and a working group. Working group members have been recruited from entities that own, manage or regulate shellfish beds, public tidelands and other natural resources, including shellfish farmers, public agencies and tribes. Their dialogue is as essential to the success of the study as scientific and technical contributions.

At the conclusion of the study, the working group members will be equipped with the tools to form an ongoing management collaborative.

New Tools for Collaborative Management

A management collaborative will need tools to apply ecosystem-based principles to the issues faced in Willapa Bay and Grays Harbor. This study will produce the following:

  • a shared understanding among scientists, resource managers and shellfish farmers of how the ecosystem functions and what is at risk,
  • objective methods for assessing how shellfish farms and other tidelands contribute to habitat values and ecosystem processes in the bays,
  • ecosystem-based aquaculture practices that optimize the value of shellfish farms for both shellfish production and as habitat, and
  • options for an ongoing structure for collaborative management, patterned after forest management collaboratives or other proven models.

Opportunities for Public Involvement

The Washington Coast Shellfish Aquaculture Study is an applied research project to assist planning and collaboration amongst the working group members and is not a public decision-making process. However, the public’s input is appreciated.

  • The project team will host four workshops over the next two years to allow in-person working group dialogue and the exchange of scientific and technical information. The public will be invited to hear from local, regional and global experts and observe the working group’s dialogue.
  • The study will share research findings on this website.
  • Public questions and comments will be collected at the workshops and via surveys on this website.


A suite of four workshops are scheduled over the next two years. These workshops will move the study forward and develop the tools needed for an ongoing ecosystem-based management collaborative amongst stakeholders.

Workshop 1:  Oct 28-29, 2019 in South Bend, WA

Workshop 2: Spring 2020

Workshop 3: Fall 2020

Workshop 4: Spring 2021


Projects currently contributing to this study are funded by Washington State appropriations, NOAA’s Office of Aquaculture and the National Sea Grant College Program.

Below is a chart illustrating the working group process that will be followed over the next three years:

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