California Sea Grant College Program

This report summarizes the activities and accomplishments of the Zostera japonica Eradication Project conducted under Humboldt Bay Harbor Recreation and Conservation District Permit No. 03-03 during the period October 21, 2009 to December 31, 2010. The Z. japonica Eradication Project is a cooperative effort involving University of California Sea Grant Extension staff, California Department of Fish and Game staff, and Humboldt State University student interns. Project Background

This ongoing eradication project represents the front line of defense in California against a non-native eelgrass that rapidly colonizes areas of unvegetated mudflat. Native to Asia, Z. japonica has become established on tidal flats from Boundary Bay, British Columbia to Coos Bay, Oregon. The detection of dwarf eelgrass (Zostera japonica Aschers and Graebn) on Indian Island in Humboldt Bay, California, in June 2002 represents the southern extent of its range in the Eastern Pacific and it is the first time this introduced species has been encountered in California