Many aren't so optimistic about the reintro of sockeye fry into Okanagan Lake given all the signs of a system in serious imbalance - primarily due to the failed mysid introduction and the impact of all the irrigation impoundments on all the tribs, which disrupt the flow of nutrients into Okanagan Lake (i.e trapped in the sediments behind the many irrigation dam structures). According to the Okanagan Lake Action Plan, the nutrient imbalance has caused a dramatic decrease in the productivity of the lake, which is compounded by the fact the mysids are a major competitor for groceries with juvenile trout and kokanee while not being bioavailable as prey to larger fish due to their diurnal migration to the depths when the sun's up. Net effect is a reduction in both the total numbers and average size of kokanee in the lake over the past couple of decades. When both size and numbers go down at the same time, red flags go up. If you throw millions of additional hatchery sockeye fry into the competitive mix without addressing the base productivity of the lake, it's just more mouths competing for very limited groceries.
Not dissimilar to Russia and Alaska pumping billions of hatchery chum and pink fry into the North Pacific during a cycle of lower ocean productivity - as we've all seen it doesn't bode well for the wild stocks competing for the limited food supply.
Unfortunately not as simple as just building a hatchery and pumping out fry when you're dealing with aquatic ecosystems. I, along with many others, would argue that the successes being witnessed in the Okanagan d/s of McIntyre Dam and in Osoyoos Lake are primarily due to the development of the "Fish/Water Management Tool" that directs the management of flows and lake levels, not hatchery enhancement. Prior to this tool the Ministry took a flood risk averse approach that did two things - scoured alevins out of redds in the early spring and caused a thermocline "crunch" in the ultra-warm Osoyoos Lake (sockeye/kokanee fry only rear in the North basin of Osoyoos Lake and even there the small window of water cool enough but with enough oxygen gets so small it is the limiting factor for number of fry the lake produces). Since the tool has been used redd scour hasn't occurred and the lakes carrying capacity/survival of fry to smolt has risen dramatically. Development of this tool was funded by the Douglas County Public Utility, in partnership with ONA, as part of their Endangered Species Act obligations, as referenced by sly karma above.
Anyway, good things are happening due to the ESA's requirement the US public utilities spend dollars to recover endangered Columbia salmon stocks and, due to the great work by ONA, they see that they can get great bang for their buck north of the border.
Ukee