Abundance, Survival and Productivity

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Abundance, Survival and Productivity
Nez Perce Tribal Hatchery (Spring Chinook-Newsome
Creek)
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(No Transcript)
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Management Assumption(Adult abundance and goals)
We can describe annual (and 10-year geometric
mean) abundance of natural and hatchery origin
adults relative to management thresholds (minimum
spawner abundance) within prescribed precision
targets.

• Redd count trends
• Hatchery and natural-origin fish abundance
• Redd count - escapement correlation

Newsome Creek
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Redd Count Trend
Number of Redds
Newsome Creek
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Adult Abundance and Goals
(Hatchery and natural escapement)
Ecological Escapement (4,048)
Sustainable Harvest (1,766)
Adult Escapement
Viable Threshold (214)
93
0
Newsome Creek
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Adult Abundance and Goals
(Redd count vs. escapement regression)
R2 0.81
Fish/redd 5.8
Newsome Creek
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Management Assumption(Run forecasts)
Hatchery and natural origin adult returns can
be adequately forecasted to guide harvest
opportunities, broodstock collection and weir
management.

• Annual Run predictions

Newsome Creek
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Run Forecasts
(Observed escapement and Run prediction)
Run Prediction
Observed Escapement
Newsome Creek
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Run Forecasts
(Observed escapement and run prediction)
Run Prediction
Newsome Creek
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Management Assumption(Harvest)
Hatchery and natural origin adult returns are
produced at a level of abundance adequate to
support fisheries in most years with an
acceptable level of impact to natural-spawner
escapement.

• No targeted harvest in Newsome Creek above the
  weir has occurred
• Acceptable harvest levels are established
  annually by co-managers and NOAA

Newsome Creek
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Management Assumption(Escapement management)
Management methods can be effectively implemented
as described in management agreements and
monitoring and evaluation plans.

• Hatchery fraction of returns and on the spawning
  ground
• Weir efficiency estimates

Newsome Creek
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Escapement Management
(Hatchery fraction in escapement and in spawner
abundance)
Newsome Creek
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Escapement Management
(Weir efficiency estimates)
Newsome Creek
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Management Assumption(Productivity comparison)
Productivity of supplemented populations is
similar to productivity of populations if they
had not been supplemented)

• Natural juvenile production over time
• Recruit per spawner

Newsome Creek
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Productivity Comparisons
(Natural juvenile production over time)
Percent Composition
Total Abundance (Thousands)
Newsome Creek
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Productivity Comparisons
(Recruit per spawner summary utilizing smolt
equivalents)
Newsome Creek
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Management Assumption(Juvenile survival)
Life stage-specific survival is similar between
hatchery and natural-origin population components.

• Release to Lower Granite Dam
• SARs

Newsome Creek
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Juvenile Survival
(Life stage specific survival of natural origin
fish to Lower Granite Dam)





P lt 0.05
Newsome Creek
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Juvenile Survival
(Release to Lower Granite Dam comparison of
natural and hatchery pre-smolt origin fish)


Survival Probability


P lt 0.05
Newsome Creek
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SARs LGD to Newsome Creek
Partial Return

P lt 0.05
Newsome Creek
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Summary

• Forecast method needs revision and is dependent
  upon age structure of returning fish
• Natural Production does occur in Newsome Creek
• Recent population trends are down
• Newsome Creek has limited winter habitat
• Redd counts can be used to estimate escapement
• Supplementation remains needed to assure adequate
  adult returns to meet restoration goals.

Newsome Creek