Cascumpec Bay is a large, shallow saltwater bay on the northern coast of Prince Edward Island, covering approximately 40 square kilometres. It opens to the Gulf of Saint Lawrence but is protected from its full force by the Cascumpec Sand Hills, a barrier island with extensive dunes. The bay receives freshwater input from several rivers, including the Kildare, Mill, Foxely, and Trout Rivers, creating productive estuaries where salt and fresh water mix. The surrounding landscape is primarily agricultural, with notable exceptions being the peat-rich Black Banks area at the southern end and the important bird habitats of the barrier islands. The bay is renowned for its shellfish aquaculture and supports a variety of inshore fisheries.