A good bit of it was that when Coho go right through the bay and up river to stage without pausing they do not bite well until they come to a stop to stage up. Hatchery fish have a tendency to be less aggressive than wild due to hook & line harvest ( ocean / all ) steadily removing the aggressive ones in any year and over time. All that said if the wild component is in the head down and run up mode the hatchery fish will mirror the behavior but on steroids but they will stop and you can get them. The key is finding out where they are staging. Get them there while newly arriving they can be caught.