Oyster reefs provide valuable habitat for many ecologically and economically important species, as well as stabilising benthic and intertidal habitats. Their bioactivity and structure creation leads to a greater abundance and diversity of other aquatic species. This book focuses on the eastern oyster's aquaculture and diversity of associated species; the cadmium conundrum in British Columbian oysters; the problems and risks related to an exotic oyster introduction case; and the expansion of distribution among spionid polychaetes by accompanying oyster shells during transportation.