Throughout spring, summer and fall, these open shallow waters serve as a major foraging area for thousands of gulls and terns as schools of fish occupy the waters near shoals year-round. It is also important in winter for feeding gulls and Northern Gannets. Common Terns are prevalent from May to September; Forster's Terns from mid-March to November and Royal Terns from August to October. Bonaparte's Gulls also use the site in the winter although their numbers fluctuate widely. In spring, it is an essential staging area for many species. From about February to April, up to 185,000 Black and Surf Scoters, and 3000 Red-throated Loons, gather here in anticipation of their journey north. Common sightings of pelagic birds include Wilson's Storm-Petrels in June and July, and Parasitic Jaegers in October.

The Mouth of Delaware Bay Important Bird Area includes the shallow waters at the mouth of the Delaware Bay located between the southwestern tip of Cape May Point, New Jersey and Delaware. The IBA encompasses Prissywick Shoal, Eph Shoal, Middle Shoal, Overfalls Shoal, Somers Shoal, and the unnamed rips closer to Cape May Point. These waters and shoals provide extremely valuable foraging and staging habitat for water birds year-round.