Hi wb,
Let's focus on the positive ...
1. You are catching, not just the size you would like or sometimes you get sea robins.
2. You are fishing an area known to produce.
3. Your equipment and rigs work as you are catching fish.
4. Killies are known to catch.
There are any number of things to help. Hopefully some folks will weigh in that fish the SH Channel more than I.
1. Try different bait. Squid/sand eels and some will tell you gulp may improve your catch size.
2. Rig selection ... are the sea robins hitting the high hook? If so, try a fishfinder rig.
3. Rig selection (alternative) - try bouncing a bucktail tipped with a killie, squid or gulp.
4. Tides - is this happening on one particular tide? Be aware of the interaction of tide and catching.
5. Try a different area - the fishing pressure may be too great in the area you are fishing.
6. Trends - when you fished, was there a recent storm. If so, it will put the bite off as the fresh water runoff will slow fishing for a few days.
These are some of the things I would examine. I may also look at whether I am fishing the flats, droppoffs or middle of the channel (this time of year I would consider the dropoffs and middle of channles as the water is cooler).
Without fishing with you, I cannot evaluate technique, but bouncing, slow up and down with pauses and just dragging the bait work at different times.
Good luck,
Capt. Ed