Council adopts 2025 salmon abundance forecasts; states recommend adjusted weighting for Oregon‑Production‑Index coho forecast

The Pacific Fishery Management Council on March 6 adopted the council staff’s 2025 preseason stock abundance forecasts, acceptable biological catches (ABCs) and annual catch limits (ACLs) for salmon, with one specific exception: the council accepted an alternate Oregon Production Index Hatchery (OPIH) coho forecast recommended by the states of Oregon and Washington.

What the council adopted: A motion to adopt the 2025 abundance forecasts, ABCs and ACLs (agenda item E2) was made by Council Member John North and seconded by David Sones. The motion included a specific exception: for the OPIH (hatchery coho) forecast, the council adopted Washington and Oregon’s recommended forecast of 493,640 adult coho rather than the value produced by the initial preseason model run.

Why the OPIH forecast changed: At a February technical meeting, scientists raised concerns that the ARIMA ensemble forecast adopted in late 2023 gave undue weight to a lagged Pacific Decadal Oscillation (PDO) index that in 2024 diverged from regional sea‑surface temperature indicators, producing a record‑low OPIH forecast (312,551) that conflicted with other indicators — notably the Oregon Coast Natural coho forecast. Washington and Oregon scientists tested alternatives to improve forecast performance over a 15‑year retrospective and found that applying exponentially decaying year weights (most recent years weighted more heavily, a 25% decay rate) reduced mean absolute percent error in hindcasts and produced a higher OPIH forecast (493,640). The states recommended adopting the adjusted forecast for 2025 and returning the methodology to formal review during the normal methodology cycle.

Scientific and advisory views: The Salmon Technical Team (STT) and the Scientific and Statistical Committee (SSC) discussed forecast performance. The SSC recommended that forecasts include standardized uncertainty measures and suggested using frameworks (for example, Satterthwaite and Shelton 2023) to identify forecasts that need targeted methodological work. The Salmon Advisory Subpanel supported the state proposal to weight recent years more heavily for 2025, noting the socioeconomic risk of an incorrectly low coho forecast.

Klamath and other stocks: The STT reported Klamath River fall Chinook remain overfished and that the Klamath rebuilding plan is still active; the stock’s 2025 forecast was much lower than in 2024, prompting concern about de minimis exploitation limits under the control rule. The council and NOAA staff noted the 2024 field conditions and survey complications in the Klamath Basin as contributing factors.

Council action and next steps: The council adopted the forecasts and ACLs as presented in Preseason Report 1, with the states’ OPIH forecast substituted by the jointly recommended 493,640 figure. The council asked NOAA and regional science centers to provide clearer uncertainty metrics and to continue work on forecast methodology review; several participants urged that the methodology change be examined further in the upcoming methodology review cycle.

Ending: The council’s adoption sets the regulatory starting point for 2025 fisheries planning. Members instructed staff and agencies to provide additional documentation of forecast performance and to address the SSC request for standardized uncertainty reporting.