This project investigates whether Giant Pacific Octopus (Enteroctopus dofleini) predation may help maintain the sponge–scallop mutualism in the Salish Sea. Although sponge encrustation on spiny scallops (Chlamys hastata) has traditionally been associated with protection from sea stars, this study found that octopuses strongly preferred non-encrusted scallops, suggesting octopus predation may also be an important selective force favoring sponge-covered scallops.