US Environmental Protection Agency (EPA), Region 10, October 2023 – September 2027
A pressing new challenge that has emerged in the Salish Sea region is the European green crab (EGC) invasion, which resulted in an Emergency Proclamation by the governor of the State of Washington. Washington Department of Fish and Wildlife began implementation of necessary emergency measures to eradicate or to prevent the permanent establishment and expansion of EGC. EGCs are benthic invertebrates characterized by a highly dispersive pelagic larval phase and a relatively slow-moving benthic adult phase. The spread of EGC is largely driven by the dispersal of its early life stages (i.e., larvae). Larval dispersal in the water column depends on both physical transport and biological factors. Due to the inherent complexity of conducting field and experimental observations, biophysical individual-based models have been developed to investigate the importance of different physical and biological processes for larval dispersal. Thus, PNNL is developing a biophysical larval dispersal model for EGC in the Salish Sea and its application to predict EGC spatial distribution and spread. In addition, PNNL is performing EGC environmental DNA surveys to provide additional input data and output validation for the model.
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In support of a multi-agency effort in response to the European green crab (EGC) invasion of the Salish Sea, a biophysical larval dispersal model was developed, using information on EGC early life stages dynamics, monitoring data, and outputs of the Salish Sea Model. The larval dispersal model of EGC is a coupling of the Salish Sea Model with a larval dispersal model Ichthyop (Lett et al. 2008). The model application and forecasts will inform management action and response planning efforts for EGC in the Salish Sea.
To ensure accurate model outputs, future simulations will use data of current EGC locations in the Salish Sea to inform model release sites of simulated larvae. As such, the team is currently gathering data of EGC trapping efforts done by government agencies and Tribal Nations. (If you have EGC trapping data, please reach out to us!) We also performed an environmental DNA (eDNA) field campaign in Summer 2024. The results of this field campaign will further inform the model for EGC simulated larvae release and settlement locations.
This project started in October 2023 and work is ongoing.
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End of summer field campaign. Photo credit: Lenaig Hemery
Contacts and Project Team
Dr. Lysel Garavelli, Modeling Task Lead, Pacific Northwest National Laboratory
Dr. Lenaig Hemery, Environmental DNA Task Lead, Pacific Northwest National Laboratory
Dr. Lily Engel, Postdoctoral Research Associate, Pacific Northwest National Laboratory
Presentations
[1] Engel L.M., T.P. Khangaonkar, and L. Garavelli. 02/19/2025. “Larval Dispersal Modeling of the European Green Crab.” Presented by L.M. Engel at WDFW European Green Crab Managers Symposium, Online, Washington. PNNL-SA-208533.
[2] Engel L.M., M.R. Premathilake, N. Barrier, T.P. Khangaonkar, N. Georgas, E. Day, and L.G. Hemery, et al. 12/13/2024. “Modeling larval dispersal and its implications for marine ecosystem management.” Presented by L.M. Engel at AGU Fall Meeting 2024, Washington, District Of Columbia. PNNL-SA-206232.
[3] Engel L.M. 04/22/2024. “Environmental Modeling for European Green Crab Management.” Presented by L.M. Engel at Environmental Modeling Class Guest Lecture, Tacoma, Washington. PNNL-SA-197050.
[4] Garavelli L., T.P. Khangaonkar, M. Premathilake, and L.M. Engel. 02/20/2024. “Coastal ecosystem vulnerability to an invasive species – the European Green Crab.” Presented by L. Engel at Ocean Sciences Meeting, New Orleans, Louisiana. PNNL-SA-194822.
[5] Engel L.M., L. Garavelli, M. Premathilake, and T.P. Khangaonkar. 02/01/2024. “European Green Crab Larval Dispersal Modeling.” Presented by L. Engel at EGC Larval Workshop, Mt. Vernon, Washington. PNNL-SA-193860.
Publications
[1] Engel, L., Premathilake, L., Barrier, N., Khangaonkar, T., & Garavelli, L. (2025). Larval connectivity for European green crab management in the Salish Sea and surrounding waters. Marine Ecology Progress Series, 754, 77-92. https://doi.org/10.3354/meps14778