2023 Snake River Basin Fall Chinook, Coho, Steelhead Update

The following updates for the Snake River Basin Fall Chinook, Coho, and Steelhead fisheries was provided by Jack Yearout on October 11, 2023, for Nez Perce Tribal Members.

Fall Chinook

The following table describes the most recent projection of Fall Chinook to Lower Granite Dam, broodstock removal, and projected run above Lower Granite Dam after broodstock removal. The total projected run for adult Fall Chinook is over 41,000 fish, comprised of 8,459 natural fish, 17,623 unclipped hatchery fish, and 15,384 clipped hatchery fish. Total broodstock removal was 3,100 adults, comprised of 1,308 natural fish, 1,258 unclipped hatchery fish, and 534 clipped fish. Broodstock needs have been met for 2023. After broodstock removal, we project at total of 36,710 adults above Lower Granite Dam, comprised of 7,253 natural fish, 15,447 unclipped hatchery fish, and 14,010 clipped hatchery fish.

Based upon these return projections, broodstock removal, and total number of fish above Lower Granite Dam, the following table details the harvest shares, harvest to date, and harvest remaining.

To date, the NPT has harvested a total of 2,857 adult Fall Chinook, comprised of 536 natural fish, 1,072 unclipped hatchery fish, and 1,249 clipped hatchery fish. This is the largest harvest of SRB Fall Chinook in recent memory by the NPT! As you can see, there is still over 4,400 fish remaining for the NPT to harvest. Unfortunately, the quality of the Fall Chinook is declining rapidly, and the fishing effort and harvest is winding down. The NPT will need to continue its efforts of growing this fishery to take full advantage of all available fish in future years.

Coho

The following table describes the most recent projection of Coho to Lower Granite Dam, broodstock needs, harvest targets, harvest to date, and harvest remaining. We currently project over 17,000 Coho above Lower Granite Dam comprised of 13,583 fish destined to the Clearwater, and 3,642 fish destined to the Lostine River in the Grande Ronde basin. This is a very good Coho return. The broodstock need of 1,619 for the Clearwater component of the run will be collected primarily at the Lapwai Creek and Clear Creek trapping locations. There is no broodstock collection requirement for the Lostine releases. Based upon initial coordination and negotiations with the states (IDFG, WDFW, ODFW), we have taken a precautionary approach with regards to harvest management. We leave a large buffer of fish to ensure broodstock collection occurs, and to also provide fish for supplementation on the landscape. Based upon this coordination, both the NPT and the states plan for harvest with what turns out to be an approximate 21% harvest rate allocation for each party. For 2023, this works out to 3,699 total Coho for both parties.

To date, the NPT has harvested 349 Coho, which is under 10% of the total target. The NPT has 2,441 Coho remaining to harvest. As a comparison, the states (IDFG, WDFW, ODFW) have harvested less than 100 fish to date. Like the Fall Chinook, the quality of the Coho will decline as we approach November, and the fishing effort and harvest will begin to wind down. The NPT will need to continue its efforts of growing this fishery to take full advantage of all available fish in future years.

Steelhead

The orange table below describes the total Steelhead return to date at various Idaho release locations above Lower Granite Dam based upon pit tag data. Based upon this pit tag data, we currently estimate a total of 31,160 hatchery steelhead are above Lower Granite Dam that are returning to the Clearwater, Salmon, and Snake River basins.

Based upon window counts, we estimate 52,797 steelhead are above Lower Granite Dam, which also includes fish destined to the Grande Ronde and Imnaha river basins. Of this total, we estimate 38,577 clipped and 14,2220 unclipped fish. These steelhead returns are comprised of both A Index (smaller) and B Index (larger) fish.

Most of the NPT harvest of steelhead occurs in the Clearwater River on B Index steelhead. The following table has the forecast to the Clearwater River, the Broodstock Needs, and the projected harvest share for hatchery B Index steelhead. The run is currently coming in much higher than the preseason forecast.

The below tables have the most up to date information on NPT harvest of steelhead in the Snake River Basin.

All harvest at Ahsahka in the North Fork of the Clearwater is on B Index steelhead. With a harvest share of over 6,700 fish, the NPT has over 6,000 fish left to go to reach its harvest share. This fishery will continue thru the spring of 2024 and end in late March/early April.

The above gillnet harvest data for steelhead contains harvest that has occurred in the Lower Granite pool, at the confluence of the Snake and Clearwater rivers in the Lewiston/Clarkston area, and in the Clearwater River. A portion of these fish harvested are B Index steelhead, and a portion of these fish are A Index steelhead. In our postseason analysis process, we will allocate this harvest out to all the various release/return locations.

The take home message is that there are approximately 6,000 B Index steelhead left to harvest for NPT, and a very large number of A Index steelhead available. Like the Fall Chinook and Coho fishery, the NPT will need to continue its efforts of growing its steelhead fishery to take full advantage of all available fish in future years.