Zostera japonica management on commercial clam beds in Willapa Bay general permit

We issue coverage under this general permit when shellfish growers choose to use an herbicide (imazamox) to control the non-native eelgrass Zostera japonica on their commercial clam beds. Zostera japonica is a class C noxious weed that may be controlled on commercial clam beds but does not include use for control on geoduck and oyster beds. Physical and mechanical methods of Zostera japonica control are not regulated by this permit. Read our blog to find out more about the Zostera japonica permit.

The current permit went into effect April 4, 2020 and expires on March 3, 2025.

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Current permit and related documents

Click the map to enlarge.

Map of treatment areas

This map shows where treatments to control Z. japonica have been done between 2019 - 2023. An average of 82 acres of clam beds have been treated each year during this time. The total area of Willapa Bay is around 80,000 acres, with approximately 8,000 acres covered by the native eelgrass Z. marina, and about 6,000 acres covered by the invasive eelgrass Z. japonica

Permit reissuance

We invited public comments on the draft permit from Nov. 21, 2024 to Jan.14, 2025. A formal notice was published in the Washington State Register on Nov. 20, 2024.

Comments we recieved on the draft permit are available to view online. An official response to comments will be included as an appendix to the Fact Sheet when the final permit is issued.

Documents to support the draft general permit:

Public workshops and hearings

During the two workshops, in Dec. 2024 and Jan. 2025, we explained the proposed changes to the permit and answered questions. Immediately following the public workshop, the hearing provided an opportunity for people to provide formal verbal testimony. We also invited written comments on the draft permit. 

We held an in-person informational workshop in Nov. 2024 to discuss the draft permit. A presentation on the draft permit was given, followed by questions and answers. No formal comments were taken during this meeting.

Timeline

Nov. 21, 2024 through Jan. 14, 2025: Formal public comment on the draft permit
April 2025: Proposed permit reissuance.
March 3, 2025: Current permit expires

Permit application, forms, and resources