Successful commercial aquaculture operations have grown in the Pacific Northwest and the Canadian West Coast on two exotic species Crassostrea gigas and Tapes philippinarum introduced from Japan during the 20th Century. Introduction of the Asian oyster C. ariakensis was proposed as a means for recovering distressed oyster fisheries in Chesapeake Bay, but it was not pursued after extensive public review deemed the practice too risky. However due to increased global shipping, exotic bivalves are being transferred worldwide. The recent introduction of a Western Hemisphere mussel Mytella charruana into the Philippines provides a good case study of shellfish aquaculture industry opportunities and challenges associated with an accidental introduction.