Cramer Fish Sciences Research Project

Coleman National Fish Hatchery Fall Run Chinook Salmon Survival


Fall run Chinook salmon produced at the Coleman National Fish Hatchery (CNF) support the majority of commercial and recreational salmon harvest in California.  With a yearly production target of ≈12 million juveniles, operations at Coleman can have a significant impact on economically valuable fisheries.  Juveniles raised at the hatchery are released into Battle Creek and then migrate down the Sacramento River and through the San Francisco Estuary before reaching the Pacific Ocean.  Juvenile salmon are released in two batches within approximately 10 to14 days of each other with the first release occurring in early April.  Recent analysis of coded wire tag returns suggests that the first releases survive at a higher rate than the second releases resulting in a loss of production.  Cramer Fish Sciences is collaborating with the US Fish and Wildlife Service, UC Davis, NOAA and UC Santa Cruz to investigate the magnitude and spatial location of mortality for juveniles migrating through the Sacramento River and Delta during these two time periods.


The project has three specific technical objectives:

  1. Estimate survival of juvenile salmon in each of the two release periods.
  2. Generate reach specific survival estimates to identify areas of increased mortality among releases.
  3. Identify habitat features and environmental variable associated with high mortality habitats.


Fall run Chinook salmon will be implanted with JSAT acoustic transmitters that will allow us to tag salmon as small as 6 grams which is more representative of the population than larger late fall run juveniles used in previous studies.  In each of the next three years, 150 fish will be tagged and released along with the two production releases from CNF.  Seven days following each release from CNF, another 150 fish will be tagged and released in the Sacramento River near the City of Sacramento.  This phased release will allow us to get a more precise estimate of survival through the Delta and is timed to coincide with when we expect fish released at CNF to be passing Sacramento.  Over 70 acoustic receivers will be deployed from Battle Creek to the Golden Gate Bridge that will allow us to estimate reach specific survival, entrainment into different migration corridors and migration speed.


A pilot study has been completed and we are currently processing data from receivers.  Releases are scheduled along with full monitor deployment in 2013.