On the strong incoming tides the salmon head up river and don't feed only defend there spawning grounds so the bites are more random out of aggression.
There are no spawning grounds in the Tidal Fraser River...
The Tidal Fraser River is a large travelling corridor. When the tide starts going out, fish travelling in the middle will indeed head downstream with the current, but they often circle around and travel more closely to shore to head upstream again.
The water is in the Tidal Fraser River is a mixture of fresh and salt. Under this condition, returning salmon go through a change in osmoregulation. Before transforming completely back into a freshwater organism, feeding still occurs. Once awhile, on very rare occasions, I have seen pink salmon chasing baitfish on the surface when fishing in the Tidal Fraser River.