Purple and Ochre sea stars (Pisaster ochraceus) preying on Pacific blue mussels (Mytilus trossulus). Also seen are Green Surf Anemones (Anthopleura xanthogrammica), Short Plumose Anemones (Metridium senile), barnacles, limpets and other intertidal invertebrates. Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.