The checklist area includes Iona Beach Regional Park, a 114 hectare Greater Vancouver Regional District (GVRD) park flanked by the intertidal foreshore. The checklist area is all of Iona Island including the immediate waters around the Iona South (often called the "West") Jetty, the North Arm Jetty, a portion of the North Arm of the Fraser River, McDonald Slough, and the Iona-Sea Island Causeway which joins Iona and Sea Islands. The checklist area does not include Sea Island.