10-12-2021, 05:52 PM
I've observed kokanee at the mouth of tributaries around the Gorge that they could not ascend. Some of those groups stayed there for the duration of the spawn until they died. Kokanee will definitely pioneer new areas though, and I see that more on years when spawner abundance is high. It's like they want to "get away from the crowds". Sometimes they're in odd locations too, that do not look like quality spawning habitat. In those cases, spawning success is probably low. There's reservoir spawning in the Gorge, and the areas they predominantly use were selected by kokanee (they were not stocked there) and spawning success can be really high. In previous years and studies, the proportion of the fishery from in-reservoir spawning groups was as high as 93%, whereas all the tributary spawning combined was only 7%. Success will obviously vary from year to year due to reservoir elevation, reservoir drawdown in the winter months, and tributary flows, sediment load, and temperature during incubation, etc. Hope it helps, Ryno