strange striper behavior

[Duke41]

About two weeks ago while entering the West Wall at Pt. Judith I saw the strangest site. 4 or so different pods of schoolie stripers in the surface swimming with their mouth wide open. It was pretty cool. They would sound and then surface again swimming pretty much in the same direction mouths open. This went on for a long time they where doing it before I got their and after I left. They would not hit anything. poppers, spoons, plastics. Although a couple of guys were getting fish by trolling trebles hooks with weights in them. Anyone seen this before, any ideas what they were feeding in that day. And oh yeah I caught a 34.5 pounder eeling Southwest ledge that day. Which I entered as a member of team S-B at snugg harbor. It was an excellent day!!