NATURES

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NATURES
Natural Rearing Enhancement System

• (Project 199105500)

Resource Enhancement and Utilization Technologies
Division Northwest Fisheries Science
Center National Marine Fisheries Service 2725
Montlake Boulevard E. Seattle, Washington
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Goals

• Increase postrelease survival
• Minimize morphological and behavioral divergence
  from wild fish

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Summary of Major Results Achieved

• Seminatural raceway habitat
• Induced wild-like behavior and coloration
• Increased instream survival
• Predator avoidance conditioning
• Increased instream survival
• Increased predator recognition
• Ecological interactions
• Improved competitive ability
• Reduced behavioral divergence
• Feeds
• Improved foraging skills
• 12 published papers

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Objectives

• 1. Evaluate the independent and interactive
  effect of NATURES seminatural raceway habitat
  variables on chinook salmon smolt-to-adult
  survival.
• 2. Evaluate the effect of NATURES predator
  avoidance conditioning on chinook salmon
  smolt-to-adult survival.
• 3. Quantify the effects of hatchery steelhead
  reared in NATURES and conventional environments
  on the growth, survival, condition, and
  emigration of naturally-reared steelhead and
  chinook salmon.
• 4. Determine the effects of NATURES rearing on
  the behavioral development of juvenile steelhead
  and the effects of competition with
  naturally-reared salmonids.

Address RPA 170-173, and 184
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Carson NFH Experiments (Obj. 1 2)

• Seminatural Raceway Habitat
• Predator Avoidance Conditioning

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Experiment evaluating the independent and
interactive effects of NATURES Seminatural
Raceway Habitat
Full factorial experimental design
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Eight rearing treatments
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Seminatural Raceway Habitat Experiment

• Response variables
• Growth
• Health
• Cryptic coloration
• Brain development
• Predation bioassay
• Instream survival
• Smolt-to-adult survival

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Predator Avoidance Conditioning Experiment

• Rearing treatments
• No antipredator conditioning
• Antipredator conditioning
• Response variables
• Instream survival
• Smolt-to-adult survival

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The effects of NATURES rearing environments on
ecological interactions between naturally and
hatchery-reared steelhead (Obj. 3 4).

• Rationale
• Ecological interactions between wild and
  hatchery-reared salmonids have been implicated in
  stock declines.
• NATURES rearing affects competitive ability and
  agonistic behavior (Berejikian et al. 2000,
  2001).

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Experimental Facilities
Quasi-natural stream (40 x 6 m)
Behavior observation flumes
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How do hatchery rearing environment and stocking
density affect interactions with naturally-reared
steelhead parr?

• Stock conventional and NATURES steelhead parr at
  different densities with naturally-reared
  steelhead and chinook parr.
• Evaluate habitat use, agonistic behavior,
  feeding, growth, survival, and dispersal of
  naturally-reared steelhead parr.

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Expected Results

• Determine the combination of seminatural raceway
  habitat components that maximize smolt-to-adult
  survival.
• Determine if predator avoidance conditioning
  increases smolt-to-adult survival.
• Quantify effects of NATURES-reared steelhead on
  the growth, survival, and dispersal of natural
  steelhead and chinook parr.
• Quantify effects of NATURES-reared steelhead on
  the habitat use, behavior, and feeding of natural
  steelhead and chinook parr.