Molt Search

The emerging invasion by European green crabs (Carcinus maenas) threatens marine resources in Washington. Early detection of small populations gives Washington State & tribal partners the best chance to reduce the spread and impact of this globally damaging invasive species.

Washington Sea Grant and Washington State University Extension have teamed up on this volunteer-based early detection program to complement existing trapping efforts across the region.

Molts can serve as an early indicator of the presence of European green crab in a new area. Molt Search aims to support broader participation in early detection of invasive European green crab spread along inland Washington’s shorelines by teaching volunteers simple, standardized steps for searching and reporting on the presence (and absence!) of European green crab molts.

Additional data on native Dungeness crab molts adds value to search efforts by filling a significant knowledge gap on the range and growth patterns of juvenile Dungeness, whose preferred habitats overlap with the new invader.

Molt Searches can be done on any shoreline in Washington state, at any time/frequency and consist of a timed collection of molts following standard protocols, a photograph of the collection, and submission of the photo via the MyCoast app.