BROODSTOCK AND WEIR MANAGEMENT

FOR CHINOOK SALMON HATCHERY

PROGRAMS IN IDAHO

Brian Leth, IDFG

Wutch you talkn bout Willis…

Segregated Broodstock

Integrated Broodstock Supplementation

Segregated Broodstock Only use hatchery-origin fish in brood

stock Developing a group of fish that is

successful in the hatchery and provides mitigation for lost harvest opportunity Selection favors fish that do well in the

hatchery environment

Hatchery and natural populations not intended to interbreed Spatial or temporal separation

Integrated Broodstock Incorporating natural fish into the

hatchery broodstock (variable levels) Minimize divergence of hatchery and

natural populations Provides a reserve for natural

population in the hatchery A better candidate for supplementing

natural populations (conservation objectives)

Supplementation The intentional release of hatchery

produced individuals into the natural environment for the purpose of contributing to natural production

NORs = Natural Origin Returns

To integrate or not to integrate…. that is the question

Depends on Management Objectives and Situation Conservation or mitigation, or both Perceived risks to natural population from the

hatchery program.

To integrate or not to integrate…. that is the question

Depends on Management Objectives and Situation Conservation or mitigation, or both Perceived risks to natural population from the

hatchery program.

Uncertainty Related to Using Hatcheries as a Tool to Recover Natural Populations Level of integration Program size relative to natural population HSRG, HRT, AHA

To integrate or not to integrate…. that is the question

Depends on Management Objectives and Situation Conservation or mitigation, or both Perceived risks to natural population from the hatchery

program.

Uncertainty Related to Using Hatcheries as a Tool to Recover Natural Populations Level of integration Program size relative to natural population HSRG, HRT, AHA

Maintain Mitigation Program while Managing Risks Reduce impacts to natural population A better candidate for supplementation

Issues/Constraints of Integration Insufficient NORs to integrate the

entire hatchery program Reduced productivity in the hatchery

environment??

Alternatives to Full Integration Stepping Stone Integration

Maintain two broodstocks Integrated component for supplementation Segregated component used for harvest

mitigation

As NORs increase there is opportunity to integrate a larger component of total production

Facility constraints associated with managing multiple broodstocks

Sliding Scale- Broodstock and Weir Management

Used to manage integrated and natural populations Decisions are driven by the size of the natural

population Reduce hatchery influence in nature and increase

natural influence in the hatchery

Escapement of NORs

Number of NORs Released Above

Weir

Max % of NORs Retained for Broodstock

Minimum fraction of Broodstock made of NORs

Maximum fraction of hatchery

spawners in nature

0-49 0 NA NA 1.00

50-99 25-50 50% 30% 0.90

100-149 60-89 40% 30% 0.80

150-299 105-209 30% 40% 0.50

300-599 210-419 30% 50% 0.50

600-899 480-719 20% 60% 0.40

900-1199 720-1009 20% 70% 0.35

1200-1999 1010-1809 20% 80% 0.25

2000-3000 1810-2810 10% 90% 0.10

Sliding Scale- Broodstock and Weir Management

Used to manage integrated and natural populations Decisions are driven by the size of the natural population

Escapement of NORs

Number of NORs Released Above

Weir

Max % of NORs Retained for Broodstock

Minimum fraction of Broodstock made of

NORs

Maximum fraction of hatchery

spawners in nature

0-49 0 NA NA 1.00

50-99 25-50 50% 30% 0.90

100-149 60-89 40% 30% 0.80

150-299 105-209 30% 40% 0.50

300-599 210-419 30% 50% 0.50

600-899 480-719 20% 60% 0.40

900-1199 720-1009 20% 70% 0.35

1200-1999 1010-1809 20% 80% 0.25

2000-3000 1810-2810 10% 90% 0.10

Sliding Scale - Broodstock and Weir Management

Influence of Natural Environment in the Hatchery

Escapement of NORs

Number of NORs Released Above

Weir

Max % of NORs Retained for Broodstock

Minimum fraction of Broodstock made of NORs

Maximum fraction of hatchery

spawners in nature

0-49 0 NA NA 1.00

50-99 25-50 50% 30% 0.90

100-149 60-89 40% 30% 0.80

150-299 105-209 30% 40% 0.50

300-599 210-419 30% 50% 0.50

600-899 480-719 20% 60% 0.40

900-1199 720-1009 20% 70% 0.35

1200-1999 1010-1809 20% 80% 0.25

2000-3000 1810-2810 10% 90% 0.10

Sliding Scale - Broodstock and Weir Management

Influence of Hatchery in the Natural Environment

Sliding Scale - Broodstock and Weir Management

Management of Programs Decisions based on size of natural

population difficult to forecast

Requires more inseason coordination/communication and adaptive management

Integrated Chinook Salmon Programs

Pahsimeroi, Upper Salmon and SF Salmon rivers

2010- Initiated Broodstock Development 2013 and Beyond

Implement sliding scale for supplementation and broodstock management

Monitor production and productivity of hatchery and natural populations and RRS

Special thanks to the staffs at Pahsimeroi, Sawtooth, and McCall

fish hatcheries.