BPA Fish and Wildlife FY 1997 Proposal

Section 1. Administrative
Section 2. Narrative
Section 3. Budget

see CBFWA and BPA funding recommendations

Section 1. Administrative

Title of project
Effects of Abundance of Hatchery Smolts on Growth, Distribution and Abundance

BPA project number   5517900

Business name of agency, institution or organization requesting funding
TBD

Sponsor type   Placeholder

Proposal contact person or principal investigator

BPA technical contact   ,

Biological opinion ID   Research M&E Program; hyp E.1

NWPPC Program number   7.2A.6

Short description

Project start year   1997    End year   

Start of operation and/or maintenance   0

Project development phase   PLANNING

Section 2. Narrative

Related projects

Project history

Biological results achieved

Annual reports and technical papers

Management implications

Specific measureable objectives

Testable hypothesis
HYPOTHESIS E.1: ABUNDANCE OF HATCHERY SMOLTS IN THE MIGRATION CORRIDOR HAS NO EFFECT ON GROWTH AND SURVIVAL OF WILD/NATURAL SALMON.

Underlying assumptions or critical constraints

Methods
Three approaches to this hypothesis can be considered.

1. Manipulation of abundance of hatchery fish.

Within the migration corridor upstream from the first hydroelectric dam, one could contemplate periodic elimination/reduction of hatchery fish from the migration corridor. While it may be impossible to take such measures as alternate-year denial of access of hatchery smolts to the migration corridor, less drastic testing is feasible. Hatchery X wild interactions in the migration corridor in the Salmon River may be studied by truck-transporting Sawtooth and Pahsimeroi hatchery fish directly from the hatchery (both salmon and steelhead) to Shoup, upstream from the Middle Fork. This would minimize straying of transported fish into the Middle Fork Salmon River, and would leave the river between Sawtooth weir and Shoup for wild/natural fish to migrate with much-reduced numbers of hatchery smolts. It would be possible to PIT-tag wild/natural migrants at Sawtooth trap, and to estimate survival rate with hatchery fish transport and without. The study could cover alternate years for four to six years.

Can this alternative be studied effectively? Problematic. The difficulty is that if survival changes in reduced hatchery cohorts are small, very large sample sizes will be required to detect significant differences between years. Furthermore, possible gains in survival in the upper river may attenuate between Shoup and the point at which survival is measured (LGR).

2. Examination of growth, stomach fullness, and survival in the smolt cohorts of 1996 and 1997.

This alternative would take advantage of the very small smolt cohorts of 1996 and 1997. It would examine stomach fullness for hatchery salmon, and growth and survival of wild salmon, in the Snake and main-stem Columbia rivers. Size data would be compared with sizes of wild smolts sampled in past years. Those data would in turn be examined with respect to possible covarying factors like river temperature units and discharge. Survival of fish from upriver traps and hatcheries to LGR would be examined and compared with survivals in 1993-1995. The low cohort abundance in 1996 and 1997 provides a surrogate for reduced abundance of hatchery fish in the migration corridor.

Can this study be done? Yes. A complication is that the small smolt cohort in 1996 and 1997 may benefit from low density and be larger and more fit that smolts in previous years that they would be compared to. Thus, it may be difficult to distinguish density dependent factors that occur in spawning and rearing areas from those that occur in the migration corridor.

3. Comparison of survival from Whitebird-Riggins traps to first dam.

Recent releases of smolts from the Salmon River trap may permit comparison of survivals to the first hydro project with survivals in the early 1960s provided by early NMFS studies, prior to the buildup in hatchery production. Survivals in 1996-97 should be examined.

Can this study be done?
Yes, but see comment above.

Brief schedule of activities

Biological need

Critical uncertainties

Summary of expected outcome

Dependencies/opportunities for cooperation

Risks

Monitoring activity

Section 3. Budget

* For most projects, Authorized is the amount recommended by CBFWA and the Council. Planned is amount currently allocated. Contracted is the amount obligated to date of printout.

Funding recommendations

CBFWA funding review group   System Policy

Recommendation    Tier 2 - fund when funds available

Recommended funding level