There are a couple things that could change these harvest shares. First, we are still evaluating how well these fish are surviving as they make their migration from Bonneville Dam to Lower Granite Dam. It looks like their survival will be below average this year which would cause these harvest shares to drop some. We will be taking a more in-depth look at this information later this week. We will also be evaluating how well PIT tagged fish represent the actual run size using genetic data collected at Lower Granite Dam. I provided more details on this process in a previous update if you are interested (Chinook update 5-2-2023). In some years, this data has increased harvest shares significantly, and in some years it has not. Next week, the harvest share data I present will include more accurate survival and PIT estimates.

Based on some comments I received last week, I wanted to share with you information how passage of Rapid River hatchery fish over Lower Granite Dam compares to fish destined for upper Salmon River fisheries (see Figure below). We use this data to help us evaluate what type of impact fisheries occurring in the lower Salmon River will have on upstream fisheries (South Fork Salmon River and upper Salmon River). As you can see in the figure below, upriver fish first started passing over Lower Granite Dam on May 19.  If we assumed these fish will migrate from lower Granite Dam to the beginning of the fishery in the lower Salmon River (Rice Creek Bridge) in 10 days, these fish would start showing up on May 29. Flows at the Slide Rapid dropped below 50,000 cfs (flows that are less of an impediment to fish passage) on May 27, meaning these upriver fish would be entering the lower Salmon River fishery with about 1,500 Rapid River hatchery fish that would have been stuck below this rapid.  Since May 27, counts of upriver fish increased slowly until June 1, and it is this surge of fish that we are most concerned about when they enter the lower Salmon River fishery.