In the spring of 2014, 11,791 Feather River fall run Chinook smolts with tag code #060448 were trucked from the Feather River Hatchery and released to net pens in northern San Francisco Bay near Tiburon, California and the Golden Gate Bridge. It was the middle of the historic 2012-2015 drought. Somehow, an estimated 323 of these fished survived (2.74%) to be recovered in fisheries, spawning grounds, and hatcheries, including 68 back to the Feather River Hatchery (Figure 1). The return rate for the Tiburon released smolts was over ten times that of the Feather River releases, five times that of Delta net pens, and over twice that of eastern San Pablo Bay pen releases (Table 1). Similar results occurred from 2013 and 2015 Tiburon releases. Results were even better from smolts barged from the Feather River to the Golden Gate in 2013.1
One wonders whether trucking and barging millions of smolts reared at the Feather and American River hatcheries would lead to more salmon commercial and sport fishery catches and improved spawning runs in the Feather and American rivers, especially during droughts. Salmon run collapses during the 2007-2009 and 2013-2015 droughts were often blamed on poor ocean conditions, as well as poor river conditions. Concerns of potential straying are unfounded, as all the Bay releases of Feather and American hatcheries have low straying rates (see Figure 1 for example). Do we want a better return on our Central Valley salmon hatchery investments?
|Table 1. Number released and estimated %return from 2014 Feather River smolt releases.2|
|Release Location||Total Released||Percent Return|
|Tiburon Net Pens||11,791||2.74|
|Lower Feather River||1,230,000||0.01-0.19|
|West Delta Net Pens||201,000||0.55|
|San Pablo Bay Net Pens||6,900,000||0.19-1.30|