The Current Magazine Spring 2015 - Page 24

Study Expands to Six Sites

Past studies have shown that salmon that have access to floodplains grow larger than their river-raised counterparts and therefore are more likely to survive predation and thrive once they reach the ocean to complete their growth cycle. For three consecutive winters the Nigiri Project, conducted on rice fields at the Knaggs Ranch property on the Yolo Bypass, has documented the fastest growth of juvenile Chinook salmon ever recorded in the Central Valley. For the first time this year, salmon were also planted at multiple other floodplain locations in the Central Valley, including two additional sites on the Yolo Bypass; a site on the Sutter Bypass; on the USGS-managed Cosumnes River Preserve; and at Dos Rios Ranch, near the confluence of the San Joaquin and Tuolumne Rivers.

Approximately 45,000 hatchery-bred juvenile Chinook salmon were released on flooded rice fields at the Knaggs Ranch on February 5th. Smaller experimental groups were also placed in enclosures at the various satellite sites. Scientists compared salmon growth rates and looked for patterns among these different floodplains on the Sacramento, American, Feather, Cosumnes and San Joaquin Rivers.

PROJECT UPDATES

Jacob Katz (left) and Carson Jeffres of UC Davis count young salmon to be stocked into the fields.