Management strategies for balancing hatchery functions with natural fish protections

1. Management strategiesfor balancing hatchery functions with natural fish protections Brad Cavallo

2. Issues Potential Actions Reduced Hatchery Production In-river Releases pHOS Excess Harvest pHOB

3. Potential Actions • In-river releases of hatchery fish • Reduces straying, but hatchery Chinook seem to have an innate tendency to stray On-site release straying rates from Vander Haegen and Doty (1995)

4. Potential Actions • In-river releases of hatchery fish • Reduces straying, but hatchery Chinook salmon seem to have an innate tendency to stray Feather River Hatchery In-river releases

5. Potential Actions • In-river releases of hatchery fish Reduces straying, but hatchery Chinook salmon seem to have an innate tendency to stray • Even among wild Chinook salmon, 2% to 9% of adult returns have been observed to stray (Keefer et al. 2005) Keefer et al. 2005. STRAYING RATES OF KNOWN-ORIGIN ADULT CHINOOK SALMON AND STEELHEADWITHIN THE COLUMBIA RIVER BASIN, 2000-2003. USGS Technical Report 2005-5

6. Potential Actions • In-river releases of hatchery fish • Reduces straying, but hatchery Chinook salmon seem to have an innate tendency to stray • In-river releases will NOT reduce hatchery fish on the spawning grounds of rivers which host hatcheries What rivers are those? American River Feather River Sacramento River MokelumneRiver Merced River

7. Potential Actions 1) In-river releases of hatchery fish At best,a partial solution. Doesn’t address domestication selection, which is probably a bigger problem than interbasin straying 2) Reduce hatchery production? Consider it, but recognize this action conflicts with original purpose and mission of our hatcheries Are other options available?

8. Issues Weirs Weirs Potential Actions Reduced Hatchery Production In-river Releases pHOS Wild Harvest pHOB

9. Potential Actions Weirs: Control access to spawning grounds (pHOS), collect wild origin fish for hatchery broodstock (pHOB)

11. Norway Weir Video

12. = fall/spring segregation weir = hatchery segregation & broodstock collection weir = existing monitoring weir planned proposed

13. = fall/spring segregation weir = hatchery segregation & broodstock collection weir planned proposed

14. = fall/spring segregation weir = hatchery segregation & broodstock collection weir = existing monitoring weir proposed

15. = fall/spring segregation weir = hatchery segregation & broodstock collection weir proposed

16. Potential Actions • Weirs. • Could be very effective for pHOS and pHOB management • Relatively easy to deploy and operate in regulated rivers • Weirs would allow flexibility for Bay releases • Provide new and better monitoring data

17. Issues Harvest Changes Harvest Changes Weirs Weirs Potential Actions Reduced Hatchery Production In-river Releases pHOS Wild Harvest pHOB

18. Potential Actions New harvest management strategies • Many possible strategies… • Reduce all harvest • Implement quotas on maximum number of wild or ESA salmon allowed to be harvested • Mark-selective: harvest only hatchery fish, release others

19. % change in spawning abundance Years In-river spawning under mark-selective fisheries (simulated populations) Source: Pyper et al. 2012

20. Potential Actions New harvest management strategies • Many possible strategies… • Reduce all harvest • Implement quotas on maximum number of wild or ESA salmon allowed to be harvested • Mark-selective: harvest only hatchery fish, release others • Terminal fisheries

21. How? Extended Net Pen Rearing

22. Terminal Fisheries “terminal fisheries” can target a specific stock or run, selectively harvest hatchery Chinook, release wild fish with very low mortality

23. Almadraba (“netting fence to catch tuna”)

24. Potential Actions • Weirs. • Could be very effective for pHOS and pHOB management • Relatively easy to deploy and operate in regulated rivers • Weirs would allow flexibility for Bay releases • Provide new and better monitoring data 4) Harvest management • Status quo strategies will cause continuing restrictions on harvest • Alternative strategies (quotas, mark-selective, and/or terminal fisheries) have potential for increasing harvest of hatchery fall Chinook

26. How do hatchery salmon inhibit recovery of natural Chinook stocks? “…hatchery stocks consistently reproduce very poorly in the wild” Araki et al. 2008. Synthesis: fitness of hatchery-reared salmonids in the wild. Evolutionary Ecology Vol. 1 (2008) 342–355 Hood River steelhead: ~40% fitness reduction per generation Araki et al. 2007. Genetic Effectsof Captive Breeding Cause a Rapid, Cumulative Fitness Decline in the Wild. Science, Vol 318, p. 100-103 Fitness

27. We have very serious salmon problems… Draft Recovery Plan for Central Valley Salmonid (NMFS 2009) • Identifies both hatchery effects and ocean harvest impacts as VERY HIGH stressors for spring and winter run Chinook

28. CAUSES Changes in Age At Maturity Pre-2010 data from Williams (2006)

29. CAUSES Changes in Age at Maturity • We have reduced diversity of age classes • Runs now consistent primarily of Age-2 to Age-4 fish As a result CV fall run Chinook: • more vulnerable to extinction from year class failures • less able to utilize available habitats and to take maximum advantage of favorable conditions