SpringSummer Chinook and Steelhead Abundance Trends

1
Idaho Natural Production
Monitoring and Evaluation Program
199107300 Idaho Department of Fish and Game
Objectives

• Manage and collect long-term monitoring data for
  wild/natural (w/n) steelhead trout and
  spring/summer (s/s) chinook salmon populations in
  Idaho.
• Measure changes in w/n steelhead and s/s chinook
  production attributable to habitat enhancement
  projects.
• Estimate life cycle survival for w/n steelhead
  and s/s chinook.

2
Spawning Ground Surveys
This Project continues and augments historic redd
count information
Chinook
Long-term monitoring data are critical to
evaluate the status and trends
Elms-Cockrum 2001
Idaho Natural Production Monitoring and
Evaluation Project 199107300
3
Parr Monitoring Database

• 17 years of parr density and physical habitat
  data with over 6,500 records.

4
Generational Trends - Parr Density
BiOp uses cohort replacement rates from adult R/S
data. This projects parr density trends
corroborate adult s/s chinook R/S trends, and
provides spatial and temporal information for
steelhead not generally available from adult
data.
Chinook
Steelhead
Hall-Griswold and Petrosky in prep.
Idaho Natural Production Monitoring and
Evaluation Project 199107300
5
Spawner to Parr

• This project identified relationships between
  parr density and w/n escapements for s/s chinook
  and A-run/B-run steelhead.
• BY 2001 escapement 44,837 wild s/s chinook salmon

Hall-Griswold and Petrosky in prep.
Idaho Natural Production Monitoring and
Evaluation Project 199107300
6
Life-Cycle Survival Rates (Smolts per Female)
This projects recent estimates of Snake River
fresh water productivity indicate s/s chinook
produced an average of 243 smolts/female in
recent brood years. Moderate density dependence
was expressed at low spawning abundance
Kiefer et al. 2001
Idaho Natural Production Monitoring and
Evaluation Project 199107300
7
Recruit/Spawner Analysis
Historic and future R/S data critical to BiOp
evaluation and the Fish and Wildlife Program.
The project continues historic estimates and
improves accuracy of run reconstructions
Schaller et al. 1999
Idaho Natural Production Monitoring and
Evaluation Project 199107300
8
S/S Chinook Length at Age Sample Sites, 2000

• Initiated because of discrepancy between PIT tag
  ocean age returns and w/n run reconstructions
  based on historic length-at-age data.

9
Estimating Age Composition of W/N S/S Chinook
Returns
Lower Granite Dam Viewing window
Adult Chinook Salmon
10
Life-Cycle Survival Rates
This project continues historic estimates and
improves estimates of life stage survival
rates Smolts/female for Snake R. s/s chinook at
LGR Aggregate s/s chinook SAR at LGR Estimate
overall and migration route-specific SAR for
PIT-tagged w/n steelhead and s/s chinook
10.0
200
8.0
150
6.0
100
Smolts/spawner
Smolt-to-adult survival (SAR)
4.0
50
2.0
0.0
0
1962
1967
1972
1977
1982
1987
1992
1997
Brood year
Petrosky et al. 2001
Idaho Natural Production Monitoring and
Evaluation Project 199107300