I second Menhaden, aka Bunker, Fat Back, Mossbunker, Pogie. An oily bait fish. Heavily Commercially fished for their oil. This fish "Flash" on the surface, but do not bite.
In certain instance there can be predators below them, but most small Spanish and Blues do not eat them. Generally the Blues and Spanish will chase Silverside Minnows (Spearing) Glass Minnows, Finger Mullet amongst others. Surf fishing on the Northern Beaches down to Oregon Inlet has been very slow.