TOPIC:

I am a multi species angler that is getting more and more involved with the effect of scent when fishing. How critical is it in salmon fishing? 

Good question!

Never hurts, Often doesn't help. But until fish can talk, we'll never know for sure. That being said - west coasters really believe in it. I'd use it all the time except it's messy.  If it's oil or water based, it washes off. If it's jelled stuff you need dishwashing soap to clean the lure.  I have been know to put small pieces of Berkley Gulp on my hooks because they leave a scent trail.  Never hurt.  

Thanks mike. I have been doing that with crappie trolling.