Clam recruitment and survival, Crab abundance in Willapa Bay 2024

Recruitment was operationally defined as 250-500 micron size class and was measured from spat samplers four times during the summer, as well as seasonal recruitment of >500 micron clams that survived to mid-September.

(Spat samplers = mesh bags of 15x10 cm, 1 mm mesh size, filled with round gravel) Predator exclosures were established at four tidal elevations at one site, and survival of 1-cm and 2-cm clams was measured over 6 weeks. Crab abundances were determined from traps mid-way through the experiment, including three native (Metacarcinus [Cancer] magister, Cancer productus, Hemigrapsus oregonensis) and one non-native crab species (Carcinus maenas).