Chum stocks are largely influenced by hatchery enhancement so not really the best indication
totally
DFO has even changed the run timing of Fraser chums.
Before the SEP program started in the 1970's Fraser chum returns peaked in Mid November. Over the decades of enhancement by DFO the November chums are virtually gone and the peak return is right on top of the Thompson steelhead return in Mid October. This was done to appease the commercial gill netters so they did not have to fish in the colder weather.
When fishing the Vedder all through December and into January there would be lots of chums in the shallows and many runs.