did you SEE the salmon in the place where you were casting?
Also, I used to be a strong believer in "salmon are idiots" and will not care about set up, bait or any of that fancy stuff like the trout do...boy was I wrong. I hooked over 40 salmon since start of September by changing up my setup to the usual "trout" version.
10lb mono mainline
8lb fluro leader
tiny size 12 hook
bead with either roe or anything "salmon" colors such as yellow, chartreuse, orange... will do WONDERFUL!
the float and weight set up is also very important, since salmon are not feeding once in spawn mode, you want to piss them off so they bite out of reaction to protect.
So youd have to make sure the bait is hitting them in the face, or in the general area. Anything drifting too high or sideways will not be productive, at least in my experience with salmon.
Setting up your split shots and using the correct float size (I use 3.5grams to 4grams on smaller east rivers) and the correct depth will guarantee fish!