Background

I. Hood River Spring Chinook Salmon Smolt Quality

The Hood River, Oregon Salmon Production Program is co-managed by the Warm Springs Tribe (WS) and the Oregon Department of Fish and Wildlife (ODFW) for supplementation of spring Chinook salmon in the Hood River system.  The current Master Plan for the Hood River Production Program (March 5, 2008 Draft) calls for a comparative hatchery release study designed to "provide co-managers with the best available information for determining a long term biologically sound and cost effective spring Chinook salmon production strategy for the Hood River Basin that balances harvest needs with ecological considerations".  Rearing facilities, both inside and outside the basin, are being evaluated for long-term use in the Hood River spring Chinook supplementation program.  The objective of this evaluation is to conduct a multi-year (2008-2018) comparative study of Hood River spring Chinook reared at three different hatchery facilities prior to being moved to the West Fork Hood River for final acclimation and release.  The facilities include, Round Butte Hatchery/Pelton Ladder (RBH) on the Deschutes River, OR; Columbia Gorge Hatchery (CGH) a.k.a. Carson National Hatchery on the Wind River, WA; Parkdale Fish Facility (PFF) on the Hood River, OR.  Each year, starting Fall 2008, returning adults will be collected in the Hood River, artificially spawned at the PFF, and gametes will be distributed to each of the respective hatchery facilities for long term-rearing to the parr-smolt stage.   Starting in Spring 2010 uniquely tagged juveniles from each facility will be moved to the Moving Falls Acclimation Pond on the West Fork Hood River for acclimation and forced release in April.  The Hood River Master Plan calls for monitoring fish health, size at release, specific growth rates, rates of precocious male maturation (age-2 minijacks, age-3 jacks) and ultimately smolt-to-adult returns (SAR's) for each brood year/release group.  SAR's for all adult year classes from all brood years will be available starting in 2013 with final returns in 2018.   These data will be used to evaluate which hatchery facility/regime is optimum for future long-term implementation in the Hood River Supplementation program.

As part of the broader Revised Hood River Production Master Plan we will conduct the following Hood River Smolt Quality Monitoring and Evaluation Study.  The overall goals will be:

A.  Monitor spring growth and smolt development at all rearing sites.

B.  Provide comparative metrics of smolt quality between rearing sites.

Specifically, we will determine if differences in growth, smolt development and early male maturation, exist between Hood River spring Chinook salmon reared at RBH, PFF and CGH and subsequently released into the West Fork Hood River for three consecutive brood years (BY) 2008-2010 released in years 2010-2012. In addition, we will monitor Deschutes stock spring Chinook reared at RBH and released into the Deschutes River and Carson stock spring Chinook reared at CGH and released into the Wind River.  These measures will allow us to:

C.  Assess the effects on growth and smolt development of transferring fish from out of basin rearing facilities (RBH and CGH) to the acclimation release site at Moving Falls on the West Fork Hood River.  

These physiological/life-history indices will provide early, predictable and replicated comparative data, before the acquisition of full SAR's in 2010-2012, for evaluating the three rearing regimes.  In addition, these metrics are independent of any potential alteration in ocean conditions that can produce variation in SAR's that are unrelated to freshwater rearing.  However, once SAR's are obtained we will be able to:

D.  Correlate physiological indices of growth and smolting to SAR to evaluate key factors responsible for potential differences in survival between release groups

This will allow us to:

E.  Evaluate rearing practices with regard to A, B and C to recommend "best" rearing practices and a long term rearing strategy for the HRPP. Results will be available for managers in late-2012.  Final correlational analysis of physiological indicators with SAR's (D) will be conducted as adults return from 2012-2018.

II.  Hood River Steelhead Trout Residualism Monitoring

          Like spring Chinook salmon, steelhead trout display significant phenotypic plasticity in both the age of smolting and age of maturation.  Hatchery-reared steelhead may adopt one of three life history pathways after release: 1) smolt and migrate to sea 2) sexually mature and remain in freshwater and attempt to spawn naturally (primarily males), or 3) "residualize" as a non-smolting and non-maturing parr and delay migration or maturation 'decisions' until the subsequent year(s).   Starting in FY 2012 we will initiate at study using physiological indices to quantify residualism rates of the steelhead trout population supplemented in to the Hood River by WS and ODFW.  These fish are from Hood River natural origin brood stock reared at Oak Springs Hatchery on the Deschutes River, OR and released in to the Hood River in May of each spring.  Prior to transfer of the fish from Oak Springs to the Hood River we will collect 300 fish and sample them for length, weight, condition factor, body lipid, pituitary glands for measurement of mRNA levels of reproductive hormones, plasma for measurement of 11-ketotestosterone and gonad tissue for mRNA measurement of reprodutive hormones and histological analysis.  Finally, we will collect gills for determination of Na+/K+-ATPase enzyme activity as an indicator of smoltification.  These indicese will be examined in a multifactorial analysis to catagorize fish into thier respective life-histories.  These data will be used to help determine rates of residualism in Hood River steelhead and to potentially help modify rearing regimes for these fish to minimize residualism rates.