Water Quality photo identifier

Water Quality Program

Zostera japonica Management on Commercial Clam Beds in Willapa Bay General Permit

The Zostera japonica Management on Commercial Clam Beds in Willapa Bay permit is a combined National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit. It allows the use of imazamox and marker dyes on commercial clam beds (excluding geoduck), in Willapa Bay only, for control of Zostera japonica eelgrass, a Class C noxious weed.

Picture of a Willapa Bay Zostera japonica eelgrass bed from Dr. Kim Patten
Zostera japonica bed photo by Dr. Kim Patten

Focus Sheet: Control of non-native eelgrass (Zostera japonica) on commercial shellfish beds in Willapa Bay

State NWCB Zostera japonica noxious weed listing

Aquatic Pesticide NPDES Permit ListServ