A new approach to Lewis River steelhead production
WDFW, PacifiCorp, Cowlitz Public Utility District, partners rolling out changes to improve steelhead fisheries and support wild steelhead conservation.
In the coming months, anglers are likely to notice changes to steelhead fishing along the Lewis River as fishery managers roll out a set of measures to improve fisheries and mitigate genetic risks for native fish populations.
These initiatives will establish a new winter-run steelhead hatchery program, strategically designed to extend angling and harvesting opportunities into the spring and cease an out of basin steelhead stock production. Additionally, fishery managers will reallocate 25,000 smolts from the early winter-run steelhead program to bolster the popular summer-run steelhead program.
Background: Lewis River hatchery reform
The Lewis River is a major tributary of the lower Columbia River that enters the Columbia near the town of Woodland in southwest Washington. A series of hydroelectric dams and reservoirs on the Lewis River near the town of Cougar — including Merwin Dam, Yale Dam, and the two Swift Dams — are owned and operated by PacifiCorp in coordination with the Cowlitz County Public Utility District (PUD).
Salmon and trout hatcheries in the Lewis River basin are overseen by the Washington Department of Fish and Wildlife (WDFW) and are operated through a funding partnership with PacifiCorp and Cowlitz PUD, in support of their Federal Energy Regulatory Commission (FERC) Lewis River Hydroelectric Project licenses and the Lewis River Settlement Agreement.
This funding supports the hatchery production of various species, including anadromous spring Chinook, coho, summer- and winter-run steelhead, along with resident fish programs including Merwin Reservoir kokanee and catchable rainbow trout stocked in Swift Reservoir and the Swift Power Canal. These are important fisheries that provide anglers with ample harvest opportunities year-round throughout the North Fork (NF) Lewis River Basin.
One of WDFW’s current and long-term objectives for the Lewis River hatchery program is to establish a naturally reproducing and harvestable population of winter-run steelhead upstream and downstream of Merwin Dam. This goal is integral to the long-term vision for the region’s steelhead populations, aligning with the Lewis River Settlement Agreement goal of establishing genetically viable, self-sustaining, naturally reproducing harvestable populations for winter steelhead, coho and Chinook salmon.
However, achieving a genetically robust and self-sustaining population of winter-run steelhead necessitates a strategic shift in hatchery management approaches.
Lewis River Hatchery Program Transition Plan
Earlier this year, WDFW collaborated with the Lewis River Aquatic Coordination Committee (ACC) to develop a comprehensive Lewis River Hatchery Program Transition Plan, paving the way for strategic adjustments to the NF Lewis River steelhead programs.
The ACC is comprised of signatory parties to the Lewis River Settlement Agreement, including WDFW, PacifiCorp, Cowlitz PUD, National Oceanic and Atmospheric Administration (NOAA), United States Fish and Wildlife Service (USFWS), Cowlitz Indian Tribe, Confederated Tribes and Bands of the Yakama Nation (Yakama Nation) and several other governmental and non-governmental organizations.
The ACC provides guidance on implementation of the Settlement Agreement and associated Lewis River Hydroelectric Project FERC licenses. This includes oversight of hatchery operations, fish passage initiatives, reintroduction efforts, and monitoring and evaluation projects throughout the Lewis River basin.
The development of the Lewis River Hatchery Transition Plan for steelhead used a structured decision-making process and carefully evaluated alternative hatchery strategies for the NF Lewis River steelhead program. The plan aims to maintain harvest opportunities for hatchery fish, while minimizing risks to the natural-origin (wild) population. This involved an in-depth assessment of existing hatchery programs and their performance, followed by a modeling approach to evaluate alternative options.
Current Lewis River Hatchery steelhead programs
Currently, hatchery steelhead production in the NF Lewis River consists of three distinct programs.
Two of these programs — one for summer-run and one for winter-run steelhead — operate as segregated programs, exclusively using hatchery fish in the broodstock without incorporating any wild fish. The primary goal of these segregated programs is to provide harvest opportunities for anglers. Broodstock is a common term in the production of hatchery fish and refers to the breeding stock used to spawn the next generation of fish. More information on broodstock and hatchery genetic management plans is available on this webpage.
Specifically, the summer-run hatchery program relies on Skamania-derived broodstock and aims to release 175,000 adipose-clipped smolts annually from the Merwin hatchery, supplemented by an additional 60,000 smolts released from an in-river cooperative net pen in the lower NF Lewis River.
Conversely, the segregated early winter-run steelhead program employs Chambers Creek-derived broodstock and aims to release 100,000 adipose-clipped smolts annually. However, Chambers Creek hatchery steelhead, originating from Puget Sound, pose a genetic risk to the natural population of NF Lewis River winter steelhead as they are considered an out-of-basin stock.
In contrast, the second winter-run steelhead program (and third distinct program) in the NF Lewis River operates as an integrated hatchery program. This program predominantly uses wild adult steelhead for broodstock with the aim of producing 50,000 unclipped (adipose fin intact) smolts annually, each tagged with a blank wire tag (BWT) for detection purposes.
The objective of the integrated steelhead program is to support the reintroduction outcome goal of the Settlement Agreement by increasing the abundance and distribution of natural spawners through transport of returning adults into the upper watershed.
Lewis River fishery performance
The Lewis Aquatic Technical Subcommittee (ATS) recently conducted an assessment of the performance of both the winter- and summer-run steelhead programs, which the ACC approved. This evaluation, which used data from WDFW’s Catch Record Card reporting system and included estimations of harvest rates (as detailed in Table 1 below), yielded several key findings:
- Total catch figures for both summer- and winter-run programs have shown a decline in recent years.
- While harvest rates have experienced a downturn for winter-run steelhead, rates for summer-run steelhead have remained high. Specifically, summer-run harvest rates have ranged from 66% in 2013 to a low of 21% in 2017.
- The Chambers Creek derived winter-run steelhead catch typically peaks in December and January, whereas the summer-run steelhead catch is concentrated in July and August.
Lewis River Hatchery steelhead program alternatives
Following a thorough assessment, three alternative hatchery strategies have been identified for the Lewis River steelhead programs. Each of these strategies share a common goal of sustaining a harvest-focused, segregated summer-run steelhead program (with potential variations in smolt plant size) and discontinuing the existing harvest-focused, segregated winter-run steelhead program.
- Alternative 1: Maintain the current conservation-based, integrated winter-run steelhead program and create a new segregated program using locally derived stock (rather than Chambers Creek stock) to provide opportunity to harvest.
- Alternative 2: Maintain the current conservation-based, integrated winter-run steelhead program and create a new “stepping-stone” program (described below) to provide opportunity for harvest.
- Alternative 3: Expand the existing integrated winter-run steelhead program along with implementing adipose-clipping of the production, thus creating a single winter-run hatchery program with a dual objective of both conservation and harvest.
Modeling approach for alternative selection
Following the identification of alternative hatchery strategies, each option underwent life-cycle modeling alongside the wild population. The details of this modeling approach are available in the Lewis River Hatchery Program Transition Plan for steelhead.
Ultimately, following a thorough evaluation process, Alternative 2 emerged as the preferred option. This decision was based on its ability to reduce genetic risks while also boosting the number of wild spawners. The stepping-stone program within Alternative 2 especially stood out for its effectiveness in preventing overexploitation of the wild steelhead population.
Lewis River hatchery steelhead program changes and implementation
The ongoing conservation-focused, integrated winter-run program (50,000 smolt plant) will remain intact, though both existing harvest-focused programs (summer- and winter-run) will be updated.
The first, and largest, change will be to eliminate the segregated Chambers Creek winter-run program and replace it with a stepping-stone program (HSRG 2014). Unlike the Chambers Creek program, which is a fully segregated, domesticated stock derived from outside the lower Columbia River basin, this stepping-stone approach will use returning Lewis River basin, first-generation (F1) adults (adult returns from the integrated hatchery program). This strategic shift aims to uphold genetic continuity between the localized hatchery and wild populations, thereby mitigating genetic risks.
This program diverges slightly from traditional stepping-stone models, maintaining consistent production goals for both integrated and stepping-stone components. Additionally, the program will prioritize the use of integrated F1 adult returns, ensuring the broodstock remains only one or two generations (F2) removed from wild parents. No wild broodstock will be used for the stepping-stone program.
As part of the transition, a second change proposes the transfer of 25,000 smolts from the winter-run harvest program to its summer-run counterpart. The stepping-stone winter-run program aims to produce 75,000 adipose-clipped smolts annually, while the summer-run program targets 200,000 adipose-clipped smolts (plus the current 60,000 net pen). The Lewis ATS evaluation anticipates this reallocation of smolts will yield positive harvest benefits.
Ultimately, these changes are designed to minimize impacts to the upper NF Lewis River reintroduction program while ensuring meaningful harvest opportunities.
Beyond their scientific and biological merits, the introduction of the stepping-stone program is expected to extend the winter-run hatchery steelhead return timeframe later in the season. Additionally, as these returning adults are anticipated to be in a less-mature condition, they are expected to offer improved table-fare, further supplementing the recreational benefits of these changes.
Summary
Beginning in 2024, a new winter-run steelhead program will be initiated on the NF Lewis River, supplanting the existing early winter-run steelhead program. Concurrently, there will be a production shift of 25,000 smolt from the winter-run steelhead program to its summer-run counterpart, as shown in Table 2.
To avoid a gap year in harvest opportunities, the last batch of early winter-run steelhead (Chambers Creek stock) currently being reared will be released in April 2024. Although these adults are anticipated to return in the winter of 2025, they will no longer serve as broodstock. Subsequently, broodstock collection for the stepping-stone program is slated to begin in March 2024, with the release scheduled for April 2025. Anglers can anticipate the availability of these fish for harvest in the winter of 2026.
With these modifications to the hatchery steelhead program in the Lewis River basin, improved angling opportunities and conservation outcomes are anticipated, including an extended return timeframe for the winter-run steelhead fishery and, ultimately, improved table quality fish.
Additional information on current and prior hatchery steelhead smolt plants is available on this WDFW webpage. More information on steelhead management is available on this webpage.
