Prior to diversion from the Black/Duwamish to Lake WA the Cedar probably had sockeye of the riverine type. They rear in rivers rather than lakes are are rather widespread but generally rare. It may have had lake-rearing sockeye, as there are systems now where the fry move down one stream the up another to access the lake. Since there are no records of large catches of sockeye by the early settlers this scenario, while possible, is not likely.

Rivers are not "intended" to have one or another species of fish. They support what the ecosystem can support. Flows too low in summer? probably few coho and steelhead. Average spawning flow 10 cfs? Probably no real Chinook as they need more water.

The fact that the stocked sockeye invaded the Cedar and flourished is evidence enough that the system could support them. Then, we cleaned up the lake of sewage (food source), we introduced more species of predators and competitors, we constrained the river behind levees and rip-rap. We diverted the flow for domestic and municipal use. The lake warmed as the climate warmed.

The ecosystem is telling us, if we were willing to listen, that it can no longer support sockeye because of the changes that have occurred in the lake.