Project: Juvenile Salmon Outmigration and Distribution in the San Francisco Estuary

View of San Francisco from underneath the Bay Bridge

Introduction:

2008-2009  is the third year of a multiyear study conducted to provide a scientific basis for policy and management of dredging work windows as it pertains to the Endangered Species Act.  Environmental work windows were established under the Long Term Management Strategy (LTMS) for the placement of dredged material in the San Francisco Bay Region to minimize potential impacts from dredging activities on Endangered Species Act (ESA) listed salmonids.  These windows were based on the geography and time of year when Chinook salmon and steelhead were thought to be absent.  Scientific records, on Chinook and steelhead movements, provided by this study will enable agencies like NMFS to improve regulations in and around the San Francisco Bay.

Alcatraz Island in San Francisco Bay

Objective:

The goal of this study is to analyze the potential impacts and exposure of migrating fish to suspended sediment from dredging and its materials. The specific technical objectives are:

(1) estimate transit times through the San Francisco Estuary.

(2) measure residence times in interest locations.

(3) identify spatial trends in migratory pathways.

Methods:

Ultrasonic receiver prior to deployment in San Francisco Bay

500 juvenile late-fall run Chinook salmon and 500 steelhead trout smolts will be released in the Sacramento River at Elk Landing in the first two weeks of February (FY07 and FY08 study years release point was Rio Vista Bridge on the Upper Sacramento River). Tagged fish are passively tracked by hydroacoustic monitors deployed throughout the estuary.  The monitor records include detections of tagged fish with coded ultrasonic beacons (Vemco tags- V7 and V9) and the associated date and time of the detected movement. 

Progress:

Monitors for 2008-2009 study year deployed in late December 2008
Annual draft report for 2006-2007 and 2007-2008 study years completed in January 2009

Personnel:

Eric Chapman (lead)

Pete Klimley Ph.D. (PI)

Department of Wildlife, Fish, & Conservation Biology, University of California, Davis

Funding Sources:

U.S. Army Corps of Engineers

Acknowledgements:

Caltrans - Chuck Morton and crew

Aquarium of the Bay - Mike McGill and Christina Salger

ECORP - Tom Keegan