Subsequently, Charles Urner published a note in the Auk regarding sight reports of Great Cormorants in the Barnegat Bay area. Although some cormorants in the area were strongly suspected to be Great Cormorants (or European Cormorants, as they were called at that time), it wasn't until 23 February 1931 that a Barnegat Bay cormorant was seen well enough to for the field marks for Great Cormorant to be made out. As Urner concluded his note: "Since identification of single cormorants in the field is so difficult unless the bird is in, or approaching, breeding plumage, or is seen very near at hand, this species is probably of more regular occurrence than the published records indicate (Urner 1932)."
Stone, Witmer. 1932. The European Cormorant in New Jersey. Auk 49:77. PDF here
Urner, Charles A. 1932. The European Cormorant in New Jersey. Auk 49:341-342. PDF here