Broodstock and Weir Management for Chinook Salmon hatchery programs in Idaho

1. Broodstock and Weir Management for Chinook Salmon hatchery programs in Idaho Brian Leth, IDFG

2. Wutch you talkn bout Willis… • Segregated Broodstock • Integrated Broodstock • Supplementation

3. 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

4. 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)

5. Supplementation • The intentional release of hatchery produced individuals into the natural environment for the purpose of contributing to natural production • NORs = Natural Origin Returns

6. 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.

7. 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

8. 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

9. Issues/Constraints of Integration • Insufficient NORs to integrate the entire hatchery program • Reduced productivity in the hatchery environment??

10. 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

11. 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

12. Sliding Scale- Broodstock and Weir Management • Used to manage integrated and natural populations • Decisions are driven by the size of the natural population

13. Sliding Scale - Broodstock and Weir Management • Influence of Natural Environment in the Hatchery

14. Sliding Scale - Broodstock and Weir Management • Influence of Hatchery in the Natural Environment

15. 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

16. 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

17. Special thanks to the staffs at Pahsimeroi, Sawtooth, and McCall fish hatcheries.