I doubt anything would of caught them, aside from snagging them. Those are fish with one thing on there agenda, spawning. They have pretty much stop feeding, occasionally you can get a reaction strike from them but not worth the time in my opinion. Also, since they are nearing the end of their life they are not the best to eat. The Cohos we caught two weeks ago off of Portage, IN are the one you want to eat. Also nothing better than a spring coho out of cold water (except a shore lunch walleye in Canada).
I've never run into Coho all bunched up at the end like that before. No way they could get over the dam. You can catch them when they start up the rivers, like the Muskegon River, but you are right, snagging may be the only way at the end. Illegal up here!
Best Coho are in the spring. We did quite well not too far from shore along the coast of Lake Michigan. You could limit out really quick when they are running.
