goose barnacles, or stalked barnacles or gooseneck barnacles, are filter-feeding crustaceans attached to rocks at avila beach,

california wildlife acorn barnacles animal avila beach barnacle blue calm clam clouds coast coastline crustaceans gooseneck horizon landscape leisure mollusc nature people ocean outdoors pacific reflection relax rock rocky sand scenic sea seascape seashell sessile shell shellfish shore sky stone sunset surf tide tourism tranquil travel water wave wild goose stalked filter-feeding attached rocks