Whats Chasing Baitfish?

Have seen bait balls/groups here & there w/ masses of birds feeding on them.  Anyone know what they probably are? Anchovies? And what could be feeding on the baitfish & what I could throw in there to catch them?

PJ

Try throwing castmasters or crocodiles into the bait balls.  Right now there are a ton of mackerel in monterey bay feeding on anchovies.  That might be what you are seeing.

MolBasser