Hi everybody. It is time for my weekly Chinook Salmon update (4/28/2020).
With only around 50 Chinook Salmon counted passing over Lower Granite Dam last week, we didn’t expect much for the opener last Saturday. The only people we saw fishing for Chinook Salmon were in the Clearwater River near Lewiston and there were only a few of those. We didn’t observe any lucky anglers and estimated no salmon were harvested over the weekend. It wouldn’t surprise me if we see our first fish harvested this coming weekend as daily counts over Lower Granite Dam will likely exceed 100 fish by then.
So let’s talk about what the run is looking like. After all, I think we are all wondering if the fish are on their way. There are a couple ways to look at this. We can look at the actual counts at Bonneville Dam, and we can look at PIT tag detections to see how many of the fish that have passed over Bonneville Dam are destined for Idaho.
The graph below shows daily counts of adult Chinook Salmon that have passed over Bonneville Dam as of yesterday (4/27/20) compared to what was counted last year (2019) and the average over the last 10 years (2010-2019). Based on this data, it suggests this year’s run has a late timing which is not too surprising seeing this is what has occurred the last four years. The not too promising thing is for us to see a decent return to Idaho this year, over the next week we need to see daily counts exceed 10,000 fish a day (off the top of the graph). This is not out of the realm of possibilities as this is what occurred in 2016. However, the later the run is the more likely this will not happen, and it is more likely we will see returns similar to the last three years where we provided small to no fisheries. Based on history, the next seven days will be telling on what this year’s spring Chinook Salmon return will be like.
The other thing we can look at is the number of Idaho bound PIT tagged Chinook Salmon that have passed over Bonneville Dam. As of April 27, only 13 Idaho bound PIT tagged salmon that we use to estimate run size have passed over Bonneville Dam. These PIT tags expand to a little over 1,000 fish – not great. Almost all of these fish are either destined for Dworshak Hatchery or Rapid River Hatchery. The number of PIT tagged fish destined for Dworshak Hatchery is promising, but unfortunately we are not seeing many fish released in other locations. Ultimately the PIT tag data tells us about the same thing as the count data at Bonneville Dam and that is the run is late and we need to see a big boost over the next week for things to look promising.
That is all I have for you this week. If you are following fish counts at Bonneville Dam, keep your fingers crossed for multiple counts of more than 5,000 fish a day.
Have a good week everyone.