In Search of the Lost Legions Attempting to account for Hatchery-origin steelhead returns to the Snake River Herb Pollard – NOAA –National Marine Fisheries Service Chris Starr – USFWS – Lower Snake Compensation Plan

Hatchery Origin Natural Origin

Hatchery-origin : Wild/natural Steelhead Run Composition at Lower Granite Dam Hatchery-origin Wild/natural Hatchery-origin steelhead Natural-origin Steelhead

Hatchery-origin : Wild/natural Steelhead Run % Composition at Lower Granite Dam Hatchery-origin steelhead Natural-origin steelhead Hatchery-origin steelhead adults Natural-origin steelhead adults

Concerns about Hatchery-origin Steelhead Adult Returns Genetic concerns: Genetic concerns: Artificial selectionArtificial selection Genetic introgressionGenetic introgression Loss of fitnessLoss of fitness Ecological Concerns Ecological Concerns Competition for mates or spawning areasCompetition for mates or spawning areas

Sometimes these concerns are expressed as: “There are Tens of Thousands of unaccounted hatchery steelhead in the Snake River Basin!” “There are Tens of Thousands of unaccounted hatchery steelhead in the Snake River Basin!” “Hatchery steelhead stray randomly and impact wild steelhead throughout the basin!” “Hatchery steelhead stray randomly and impact wild steelhead throughout the basin!” “Hatchery strays are spawning with wild fish in important natural production areas, reducing fitness and adversely impacting recovery!” “Hatchery strays are spawning with wild fish in important natural production areas, reducing fitness and adversely impacting recovery!”

Concerns for Hatchery strays in status reviews and recovery literature

But, really, not much is known about the impact of hatchery fish on natural steelhead in the Snake River basin. But, really, not much is known about the impact of hatchery fish on natural steelhead in the Snake River basin.

The Assignment to Fishery Managers: Account for the hatchery-origin steelhead that return to known sites and harvest Account for the hatchery-origin steelhead that return to known sites and harvest Summarize the data for hatchery- origin steelhead that stray between release sites or into natural production areas Summarize the data for hatchery- origin steelhead that stray between release sites or into natural production areas

Data on known removals/mortalities Hatchery rack returns Hatchery rack returns Harvest estimates/creel census Harvest estimates/creel census Natural mortality Natural mortality Return to direct stream releases Return to direct stream releases Catch and release mortality in recreational fisheries Catch and release mortality in recreational fisheries

Data on known strays/tag recoveries Wild steelhead weirs in Grande Ronde, Imnaha, and Lochsa systems Wild steelhead weirs in Grande Ronde, Imnaha, and Lochsa systems Hatchery weirs Hatchery weirs Coded-wire tag returns from weirs and fisheries Coded-wire tag returns from weirs and fisheries

Genetic Evidence of hatchery introgression into natural populations IDFG Steelhead Genetic Survey IDFG Steelhead Genetic Survey NMFS Northwest Fishery Science Center surveys NMFS Northwest Fishery Science Center surveys

Cooperators Washington Department of Fish and Wildlife – Mark Schuck Washington Department of Fish and Wildlife – Mark Schuck Oregon Department of Fish and Wildlife – Rich Carmichael Oregon Department of Fish and Wildlife – Rich Carmichael Idaho Department of Fish and Game – Paul Kline Idaho Department of Fish and Game – Paul Kline Nez Perce Tribal Fisheries – Becky Johnson Nez Perce Tribal Fisheries – Becky Johnson Shoshone-Bannock Tribal Fisheries – Keith Kutchins Shoshone-Bannock Tribal Fisheries – Keith Kutchins Confederated Tribes of the Umatilla Indian Reservation – Brian Zimmerman Confederated Tribes of the Umatilla Indian Reservation – Brian Zimmerman

How many fish can be accounted for? How many fish can be accounted for?

Distribution of Hatchery-origin Steelhead in the Snake River Weighted Average Harvest 60.9% Hatchery Rack 19.1% Direct Stream 8.7% Natural Mortality 6.4% C&R mortality 0.8% Unaccounted 4.1%

Distribution of Hatchery-origin Steelhead in the Snake River

Unaccounted HOR NOR Escapement

So, where do they go?

Numbers of natural-origin adult steelhead and hatchery- origin strays trapped at Grande Ronde River tributary weirs, (Data from Mike McLean, CTUIR ) Weir SiteRun Year Total (Strays) Lookingglass Creek (4) Upper Grande Ronde (1) Catherine Creek (3) Total (Strays)550 (5)447 (1)378 (2)1,375 (8)

Proportion of Hatchery-origin steelhead strays at three weirs in the upper Grande Ronde Subbasin 1,367 Wild/natural fish – 99.4% 8 Hatchery strays – 0.6%

Stray rates in the Imnaha Basin to run years. Courtesy of Jay Hesse (Nez Perce Tribe). LightningStray rateCowStray rate Run yearEscapementCreek(%)Creek(%)SGS(%) , , , ,

Imnaha Hatchery Returns and strays in Tributaries 11,363 Hatchery returns – Hatchery Strays detected in Tributaries

Fish Creek Weir: Hatchery Strays Hatchery-origin strays ~2% Natural-origin recruits

Rapid River Weir NOR:HOR HOR NOR

How well do the hatchery fish return to the point of release? How well do the hatchery fish return to the point of release?

Cottonwood Pond – 4,515 CWT recovered in the Snake River Basin Snake River Sport – 1,628 Grande Ronde Sport – 1,936 Cottonwood Trap Lyons Ferry Trap Others – 60 (1.3%) Clearwater Sport – 11 Tucannon Sport – 13 Salmon Sport - 30 Pahsimeroi – 1 Big Canyon - 5

Wallowa-Big Canyon 4,361 CWT Recovered in the Wallowa River Returned to Site of Release – 4,348 Strays between Facilities - 13

Idaho Rack and Harvest Recovery of fish released at racks – 6,361 CWT recovered in Snake river OK – Fish recovered at the release site or in fisheries downstream and en route - 6,324 tags Not OK – Fish recovered at the wrong hatchery rack or in fisheries off the direct route – 37 tags (0.6%)

IDFG Direct Stream Releases 1,153 CWT OK – Recovered in area of release tags (79.5%) Out-of-Subbasin– downstream – 37 tags (3.0%) In-subbasin - downstream – 48 tags (4.0 %) In-subbasin – upstream 152 tags (13.2%)

Genetic Surveys Genetic Population Structure of Snake River Basin Steelhead in Idaho (Nielsen et al 2004) : Genetic Population Structure of Snake River Basin Steelhead in Idaho (Nielsen et al 2004) : “…significant genetic population structure remains for steelhead populations within the Snake River…”

Conclusion: Fishery managers know where most of the hatchery origin steelhead go in the Snake River Basin. On the average, 95.9% of the hatchery steelhead passing Lower Granite Dam are accounted in harvest, rack returns, natural mortality and returns to sites like the Little Salmon River. The number of unaccounted fish is much smaller than has been thought. On the average, 95.9% of the hatchery steelhead passing Lower Granite Dam are accounted in harvest, rack returns, natural mortality and returns to sites like the Little Salmon River. The number of unaccounted fish is much smaller than has been thought.

Conclusion: Once within the Snake River Basin, hatchery-origin steelhead demonstrate a high degree of homing fidelity. CWT detections indicate >90% return to release sites CWT detections indicate >90% return to release sites Stray rates between facilities or in fishery detections are small. Stray rates between facilities or in fishery detections are small.

Conclusion: Detection of Hatchery strays in natural production areas is less than suspected Weirs located on wild steelhead streams catch few hatchery fish, hatchery fish are seldom observed in spawning grounds surveys, and the ongoing genetic surveys have not reported widespread occurrence of the hatchery stocks. Weirs located on wild steelhead streams catch few hatchery fish, hatchery fish are seldom observed in spawning grounds surveys, and the ongoing genetic surveys have not reported widespread occurrence of the hatchery stocks.

Uncertainties remain... There are weirs on only a few of the important wild production streams – What about the others? There are weirs on only a few of the important wild production streams – What about the others? If the few hatchery strays arrive in natural spawning areas, how successful are they – what are the impacts? If the few hatchery strays arrive in natural spawning areas, how successful are they – what are the impacts?

However….. Empirical data is fairly abundant and robust to indicate that straying of large numbers of hatchery steelhead into important natural production areas does not occur within the Snake River basin at the level previously thought. Empirical data is fairly abundant and robust to indicate that straying of large numbers of hatchery steelhead into important natural production areas does not occur within the Snake River basin at the level previously thought.

Management Implications Geographic isolation of hatchery steelhead can be an effective management measure Geographic isolation of hatchery steelhead can be an effective management measure Release fish in main stems, away from important tributary spawning areasRelease fish in main stems, away from important tributary spawning areas Release fish in areas with good public access to increase harvest ratesRelease fish in areas with good public access to increase harvest rates

Management Implications Steelhead exhibit strong homing fidelity to release sites, but… Steelhead exhibit strong homing fidelity to release sites, but… There may be a tendency to stray upstream or into nearby tributaries if fish are not removedThere may be a tendency to stray upstream or into nearby tributaries if fish are not removed

Management Implications Acclimation ponds may not be necessary, but… Acclimation ponds may not be necessary, but… Release at a pond or tributary weir will likely help with accounting for returnsRelease at a pond or tributary weir will likely help with accounting for returns Acclimation ponds allow management options with non-migratory “residual” malesAcclimation ponds allow management options with non-migratory “residual” males

Thank you… Any Questions? Any Questions? Herb Pollard, NOAA Fisheries NW Region, Hatcheries and Inland Fisheries Branch Chris Starr, US Fish and Wildlife Service, Lower Snake River Compensation Plan