Fall Chinook salmon and coho salmon update 8/29/2024

Idaho’s fall Chinook Salmon season opened on August 18, and the Coho Salmon season starts on September 1. So, I figured I better put out an update to let people know what is going on with these fisheries. In this update, I will try to answer the questions people have been asking most frequently including what are the runs looking like, what percent of the runs are being trapped at Lower Granite Dam for broodstock, and what fishing rules do you need to follow if you have both an Idaho and Washington fishing license and would like to fish the boundary waters and/or both states during the same day. 

FALL CHINOOK SALMON

Run Status

Fall Chinook “officially” started passing over Lower Granite Dam on August 18, which means we don’t have a lot to go on to evaluate how this year’s return is progressing. However, I have provided the figure below that shows how the 2024 preseason forecast (bars furthest to right) compares to previous year’s returns. This forecast suggests that this year’s return will be less than the previous four years, but still enough to provide good fishing opportunities. 

Counts at Bonneville Dam and Lower Granite Dam suggest a couple things. First, the run looks early. In fact, the 139,000 adult fall Chinook Salmon that have been counted passing over Bonneville Dam is the most we have ever seen for this time period (Aug 1 through Aug 28). The majority of these fish are destined for the upper Columbia River, but what we see at Bonneville Dam reflects on what we can expect to see upstream of Lower Granite Dam. In fact, the counts we are seeing at Lower Granite Dam for this same time period are also the highest we have ever seen. The other thing these counts tell us is the run will likely come in higher than the preseason forecast. In fact, if we look just at the PIT tagged fish that are destined for the Snake River, this data suggest that we could see over 35,000 adult fish make to Lower Granite Dam which is quite a bit higher than the 24,000 fish preseason forecast. Just how early this run is will dictate just how many fish will ultimately pass over Lower Granite Dam this year.

When and Where to Fish

To help those of you who were wondering when the best time to fish for fall Chinook is, I have provided the figure below that shows the average run timing (for the past 10 years) for adult fall Chinook Salmon to Lower Granite Dam. This information shows that the beginning of the second week of September is when fall Chinook Salmon counts at Lower Granite Dam typically peak, and once the counts peak, they typically stay up for two to three weeks. Based on the adult Chinook Salmon counts that have occurred this year, it looks like good counts (> 1000 fish/day) at Lower Granite Dam will start occurring a week earlier than normal. An important thing to realize is that when many of the fish arrive at the confluence of the Snake and Clearwater rivers, they stop migrating and hang out in the cool Clearwater River flows. Many of these fish will remain in this area until the Snake River cools down (typically around mid to late September). At this point, these fish will resume their migration upstream. What this means is the number of fish in the confluence area will build up until water temperatures cool down in the Snake River. 

For those who like to fish in the flowing rivers such as the Clearwater River upstream of the Potlatch mill, the Snake River upstream of Asotin, or the Salmon River, the farther upstream you want to fish, the later you will want to wait before you head out. As I indicated earlier, the Snake River typically cools down around mid to late September. As such, if you want to fish in the Snake River above Asotin, you won’t see a lot of fish until after mid to late September. For the Salmon River, fishing often doesn't pick up until October. Fish will enter the Clearwater River earlier than the Snake River because it has cold water, but fishing still doesn’t usually get good until late September. When looking for places to fish, it is important to know that when the fish first get to areas they want to spawn, they tend to hold in the deeper pools and runs, and then as they get closer to spawning, they will start moving into shallower water near gravels bars and pool tail-outs.

COHO SALMON

Run Status

I provided the figure below to give you a feel for how the Coho Salmon preseason forecast to Lower Granite Dam for 2024 compares to previous years. As you can see, the forecast for this year’s return is similar to what occurred last year (around 14,000 fish). Coho Salmon typically don’t start showing up at Lower Granite Dam until around mid-September so we have some time before we will understand how accurate this forecast is. However, we can glean information from counts and PIT tag detections at Bonneville Dam. As of August 28, over 27,000 Coho Salmon have been counted at Bonneville Dam. That is the second highest count we have ever seen at Bonneville dam for this time. PIT tag detections of Coho Salmon at Bonneville Dam are also promising. As of August 27, PIT tags estimated about 3,300 of these fish are destined for Idaho. If this run has an average run timing, that would result in around 24,000 Coho making it to Lower Granite Dam. It would make sense that this run is early seeing both steelhead and fall Chinook Salmon appear to have early run timings this year. If the Coho Salmon run is early, the 24,000 fish PIT tag projection will be on the high side. Regardless, this early information suggest that we will have another good Coho Salmon return to Idaho this year.

When and Where to Fish

Coho Salmon typically don’t start showing up in Idaho until mid-September, and fishing doesn’t get good until October. Good fishing can occur through much of November.  Most of the Coho Salmon returning to Idaho were reared at Dworshak Hatchery and released in Lapwai Creek and Clear Creek at Kooskia Hatchery. Some Coho Salmon were also reared at Eagle Creek Fish Hatchery in Oregon and released into a tributary of the Grande Ronde River. Although Coho Salmon will scatter throughout the Clearwater and Snake rivers, anglers tend to have the most success in those area where they congregate – the areas they were released and reared at. 

TRAPPING BROODSTOCK AT LOWER GRANITE DAM

The fall Chinook Salmon hatchery program has played a key role in why fall Chinook Salmon returns to the Snake River basin have improved dramatically since the 1980’s and 1990’s. Three hatcheries rear and release fall Chinook Salmon in the Snake River basin. Their overall goal is to release close to 6 million smolts into the Snake River basin with about 80% of these fish being released upstream of Lower Granite Dam. The broodstock for this program is collected at a fish trap located on Lower Granite Dam’s fish ladder. These fish are trapped in a manner to help meet broodstock goals and reduce handling of wild steelhead. To meet these goals this year, trapping started on August 18 with 70% of the return being trapped. For marked fish (fish that had a clipped adipose fin or some type of tag), they were kept for broodstock if their fork length was over 80 cm (about 33 inches total length) whereas if they were not marked (adipose intact and no tags detected), they were kept if they were over 70 cm (about 28 inches total length). Because the run is early, broodstock collection has been going better than expected this year. For that reason, on August 26, the trap rate dropped to 40% and the only fish kept for broodstock are unmarked fish (adipose intact and no tags detected) that are > 70 cm. What this means is that when we were trapping 70% of the run, about 65% of those fish counted at the window made it past Lower Granite Dam. Now that the trap rate is at 40% and only unmarked fish are being kept, over 80% of the fish counted at the window will make it past the dam and into the fishery. In early September, trap rates will drop to 18%.

Coho Salmon broodstock have also been collected at Lower Granite Dam in the past. However, in years when the return if large, the Nez Perce Tribe has been successful in collecting sufficient broodstock at trap sites in Lapwai Creek, Clear Creek, and at Dworshak Fish Hatchery. Because the Coho Salmon return looks like it will be good this year, it is unlikely that broodstock will need to be collected at Lower Granite Dam. 

SEASONS, LIMITS, AND RULES

I’m not going to go into details on Idaho’s seasons and rules for fall Chinook Salmon or Coho Salmon because you can review them by clicking on these links:

• Fall Chinook Seasons and Rules
• Coho Seasons and Rules

However, I will provide these key points:

Fall Chinook Salmon Seasons and Limits

• The season in Idaho started on August 18, 2024 (The North Fork Clearwater opens September 1).
• The fishery will occur in the Snake River, lower Salmon River, and much of the Clearwater River basin.
• The daily limit is three (3) adult fish (adipose clipped and unclipped fish can be kept).
• Fishing will be allowed seven days a week in all areas that are open.

Coho Salmon Seasons and Limits

• The season in Idaho starts on September 1, 2024.
• The fishery will occur in the Snake River and much of the Clearwater River basin.
• The daily limit is two (2) adult fish (adipose clipped and unclipped fish can be kept).
• Fishing will be allowed seven days a week in all areas that are open.

Fishing Boundary Waters

For those who like to fish in Washington or with a Washington fishing license in the confluence area, you can view their regulations for the Snake River by clicking on this link (WDFW Snake River Fall Chinook regulations).

For the most part, Washington has the same limits and seasons as Idaho.

One popular area to fish for fall Chinook Salmon is around the confluence of the Snake and Clearwater rivers (see map below). Where it can get complicated is for those people who have both an Idaho and Washington fishing license and fish in Washington only waters, boundary waters, and Idaho only waters. For those of you who like to do this, you should be aware of the following things. When fishing the boundary water, you can only exercise the privileges of one license at the same time. For example, if you are fishing with two rods (Idaho allows this if you have a two-pole permit, Washington does not allow this) in the boundary water, you must tag your fish on an Idaho permit. You also must follow all other Idaho regulations such as in Idaho whoever hooks the fish must tag the fish (in Washington whoever lands the fish must tag the fish). In addition, if you fish the boundary water, you are entitled to have in possession only the limit allowed by one license regardless of the number of licenses in possession.

If you plan to fish in both boundary waters and Washington only waters, I urge you to call up the WDFW (WDFW Contact Info) to understand how they will enforce various scenarios. I copied the following wording from Washington’s regulations that anglers may not be aware of. “Before utilizing a Washington fishing license or fishing Washington only waters, any fish retained while using another state’s license must be returned to shore before continuing to angle.” In other words, don’t catch a fish in the boundary water and tag it on an Idaho permit and then continue into Washington only waters with that fish in your boat.

KNOW YOUR FISH

If you plan to fish for fall Chinook Salmon or Coho Salmon, you may also encounter steelhead or Sockeye Salmon. They all have different regulations, so it is imperative that you be able to differentiate between these four species. Be aware that anglers have been catching Sockeye Salmon this year, and there is no season on them anywhere upstream of the mouth of the Snake River. There are many different sources that can help you identify the differences between these species. I have provided links below to some of the better sites.

• https://idfg.idaho.gov/fish/identification/salmon-steelhead
• https://wdfw.wa.gov/sites/default/files/publications/01384/2012-13_marine.pdf
• https://www.adfg.alaska.gov/static/regulations/fishregulations/PDFs/southeast/2019se_sfregs_salmon_id.pdf
• https://www.pac.dfo-mpo.gc.ca/fm-gp/rec/identify-identifier-eng.html

Good luck fishing!