European Green Crab Quarterly Progress Report – Winter 2024 (October 1 to December 31, 2024)

In response to the ESSB 5693 (2022 c 297) legislative budget proviso directive, this report has been authored as the tenth in a series of ongoing quarterly progress reports. This report will serve to outline the successes and challenges of ongoing European green crab (hereafter green crab) emergency response efforts in Washington state from October 1 to December 31, 2024. In addition, this report will examine green crab data for the totality of 2024 in the context of previous years (2022-2023).

The previous quarterly progress reports are available at: https://wdfw.wa.gov/publications and on WDFW’s European green crab webpage.

In 2021, the Washington Department of Fish and Wildlife (WDFW), co-managers, tribes, and partners identified an exponential increase of invasive European green crab, Carcinus maenas, in the Lummi Nation’s Sea Pond within the Salish Sea, and in outer coastal areas including Grays Harbor, Makah Bay, and Willapa Bay. On Dec. 14, 2021, WDFW Director Susewind submitted an emergency measures request under RCW 77.135.090 for green crab response to Governor Jay Inslee. On Jan. 19, 2022, Governor Jay Inslee issued an emergency proclamation (#22-02) to address the exponential increase in green crab populations across Washington’s marine shorelines. The proclamation directed WDFW to eradicate, reduce, or contain green crab populations in Washington. The Washington State Legislature approved $8,568,000 in emergency funding during the 2022 Supplemental Budget to facilitate increased green crab management efforts. In response to the legislative budget proviso directive, this report is the tenth in a series of ongoing quarterly progress reports. This Winter 2024 report will outline the successes and challenges of ongoing green crab emergency response efforts in Washington state from October 1 to December 31, 2024.

An Incident Command System (ICS) was established to deal with the complexities of the green crab management effort. Support for and coordination with co-managers, tribes, and partners is essential, as the scale of the green crab emergency is such that no one entity could ever hope to implement successful statewide management strategies alone. Washington Sea Grant (WSG), the Lummi Nation, the Makah Tribe, the Shoalwater Bay Tribe, shellfish growers and various other entities have continued their ongoing efforts managing green crab populations, closely coordinating with WDFW. The ICS also resulted in the creation and distribution of various updates including reports to the governor every 10 days and Situation Reports (SitReps) based on monthly operational periods to provide information on and ensure transparency regarding management actions taken, grant funding allocations, green crab catch numbers, trapping efforts, media outreach, and other relevant information. These Situation Reports were synthesized for the public, media, and other external audiences in bi-monthly Green Crab Public Updates published and distributed through WDFW’s Green Crab Management Updates email list as well as Department webpages, communications, and social media channels.

Representatives from many entities participating in green crab management have joined the ICS Multi-Agency Coordination (MAC) Group. The MAC Group provides a forum for these representatives to share information, establish a common operating picture, develop long-term priorities for the green crab emergency, and commit and allocate funding and other resources to enhance emergency measures responses.

During Winter 2024, the collective effort of all organizations resulted in approximately 372,631 green crab removed from Washington state marine waters, with 370,664 from the Coastal Branch and 1,967 from the Salish Sea Branch. Since January 1, 2022, approximately 1,696,190 green crab have been removed from Washington state marine waters, with 1,604,161 removed from the Coast Branch, and 92,029 removed from the Salish Sea Branch. In addition to active control trapping, Winter 2024 trap deployment for early detection monitoring occurred in areas where green crab had not previously been detected. Green crab has not been detected in the Salish Sea Branch south of the northern Hood Canal. Data on green crab abundance, body size, sex ratios, and reproductive status were collected for future analysis, along with DNA and RNA samples to assess connectivity between green crab populations.

Green crab removal numbers for Washington increased substantially in 2024 compared to previous years overall, though changes in removal numbers and catch per unit effort (CPUE) was highly variable across Management and Coordination Areas. One likely contribution to the increase in CPUE is the El Niño Southern Oscillation (ENSO) event during the winter of 2023 which supported recruitment of green crab in many management areas. At the same time, there were more trapping partners covering more sites, removing higher volumes of green crab. The green crab emergency remains a complex and nuanced situation with no universal solution to this highly variable problem.

WDFW, WSG, co-managers, tribes, and partners achieved significant progress in green crab management efforts. The European Green Crab Research Task Force continues to coordinate with green crab researchers across the Pacific coast of North America to advance research priorities to support green crab management efforts in Washington state and throughout the region. Additional progress was also made on public education and community engagement to support green crab awareness, with WDFW representatives engaging individuals at public events and producing new outreach materials. While challenges remain (e.g., preparing for the 2025 field season), the continued efforts of all parties and the clear organizational structure set previously will allow for continued success through 2025.