The Sacramento/San Joaquin is perhaps the epicenter of interactions between salmon & society
Very important region politically and ecologically
Genetic diversity of salmon abounds still but less so than historically
Spring-run Chinook historically the most abundant, lost access to tributary habitat (dam construction) and listed as threatened under the ESA in 1999
Winter-run Chinook blocked by Shasta Dam in 1945, remain spawning below the dams; Endangered under ESA in 2004
Fall-run likely as historically as abundant as spring-run; supported by very heavy hatchery production (ca. 32 million releases per year)
How much is the SF Bay Chinook salmon worth to commercial fisheries? Less than dungeness crab. But still a lot…4.7 million prior to collapse of 2008.
Value of sport fisheries more than 10x higher!
California the most populous state (38.8 million, 12% of all us); fifth largest agriculture and food commodities in world
Best soil for agriculture is in the San Joaquin but virtually all the water falls in the north (Sierra Nevada). Solution to the problem was to move the water to where it is abundant to where needed
Done through a series of canals…need to overcome geography and need pumping facilities to move water. 54% of water goes to agricultural demand, 32 % to the environment, and 14% of urban
An increasing amount of water is diverted upstream locations before entering the delta; currently 48% of water entering watershed from upstream makes it to the delta
Increasing urban demand for water and decline in agriculture
Mismatches between when water is available (spring) and when it is needed (summer)
Currently we are in a deteriorating delta area
Dams have host of issues: barriers, temperature effects, diverst water and change salinity, and costly to maintain.
Other major changes are in the delta itself…delta had very rich soils from flooding and so in the 1830s major efforts to dike and create levies to avoid flooding and tap into high value agricultural grounds, enter Bureau of Reclamation
Yolo bypass channel provides opportunistic use of good rearing habitat…but it is rarely open
How do we circumvent poor survival in the system? Many hatcheries trucking to fish to the delta…downside is that the fish stray at much higher rates
On average approximately 50% of the fish on spawning grounds are first generation hatchery fish
Have lost a lot of diversity in timing of release and size at release…consequence?
Options for additional exports do not fare well for salmon. Under scenarios of 30% more expected to drive populations to extinction