About the Class
| Taught by P. Sean McDonald |
They’re small. They’re hungry. And they’re here. The invasive European green crab (Carcinus maenas) has been called one of the world’s worst invasive species. These surprisingly tough crabs threaten the foundation of our coastal ecosystems—devouring shellfish and uprooting the eelgrass meadows and salt marshes that shelter fish, birds, and other marine life.
In this class, participants will trace the unfolding story of how European green crab arrived on Pacific shores, how they spread through the Salish Sea, and why they’ve proven so difficult to control. We’ll explore their remarkable adaptability, appetite, and ecological impacts, and learn how scientists, tribal resource managers, state agencies, and community volunteers are working together to track, trap, and contain them. Along the way, we’ll consider what this invasion reveals about the resilience of native species, the links between people and place, and the shared challenge of caring for our changing coasts.
| About Sean McDonald |
With a B.S. in Marine Biology from Western Washington University and a Ph.D. from the University of Washington, Sean McDonald is an Associate Teaching Professor jointly appointed in UW’s Program on the Environment and School of Aquatic and Fishery Sciences. For more than 25 years, he has studied the ecology, spread, and management of the invasive European green crab and its interactions with native species such as the Dungeness crab. His work blends field ecology, modeling, and collaborative monitoring to inform science-based management of coastal ecosystems across the Pacific Northwest and the broader Salish Sea.
Sean serves on several regional and national advisory groups focused on invasive species and shellfish management, including the Washington State European Green Crab Research Task Force and the Pacific Northwest Crab Research Group Coordinating Committee. A lifelong educator who began teaching as an undergraduate in an invertebrate zoology lab, he now teaches courses in environmental communication, sustainability, and supports student research in marine ecology at UW. Sean loves connecting science and people—so if you have ocean questions, he’s always happy to talk.
