Management strategies for balancing hatchery functions with natural fish protections Brad Cavallo

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

1) 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) Potential Actions

1) 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 Potential Actions

1) 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 STRAYING RATES OF KNOWN-ORIGIN ADULT CHINOOK SALMON AND STEELHEAD WITHIN THE COLUMBIA RIVER BASIN, USGS Technical Report Potential Actions

1) 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 Mokelumne River Merced River 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? Potential Actions

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

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

Norway Weir Video

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

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

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

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

3)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 Potential Actions

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

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

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

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

How? Extended Net Pen Rearing

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

Almadraba (“netting fence to catch tuna”)

3)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 Potential Actions

How do hatchery salmon inhibit recovery of natural Chinook stocks? “…hatchery stocks consistently reproduce very poorly in the wild” Araki et al 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 Genetic Effects of Captive Breeding Cause a Rapid, Cumulative Fitness Decline in the Wild. Science, Vol 318, p Fitness

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

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

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