USGS Western Ecological Research Center

Home Who We Are Where We Are What We Do Products Search Outreach Jobs Contacts

How do waterbirds respond to the bustling recreational and transit water traffic of San Francisco Bay?

Greater Scaup in San Francisco Bay --Photographer: USGS


The San Francisco Bay Estuary is a critical migratory stop-over and wintering area for diving waterfowl and other waterbirds in the Pacific Flyway. Wildlife surveys show that large numbers of unique species, such as diving ducks, guillemots and grebes, rely on Bay waters seasonally or year-round.

At the same time, San Francisco Bay is one of the most dynamic and growing waterfronts in the U.S., accommodating shipping ports, recreational and commercial boaters, and water transit year-round, not to mention special celebrations and events such as the America’s Cup sailing race. A flotilla of rafting birds and piloted vessels share our Bay.

Yet little is known about how water traffic disturbance may affect habitat use and foraging ecology of rafting waterbirds. Studies elsewhere have shown that high-speed ferry routes can discourage habitat use by waterbirds within certain distances, while boat traffic disturbance can cause waterbirds to expend more energy flying and flushing from roosting and foraging sites, and spend less time feeding — thereby losing valuable energy that could be stored for breeding or migration.

The USGS Western Ecological Research Center works with many local and state institutions to study the wildlife ecology in the San Francisco Bay Area and California at large. As part of the USGS mission to survey America’s natural resources, our scientists study how birds and other wildlife respond to different environmental factors, be it wildfires, invasive plants and predators, environmental pollutants, or human activity.

Our research projects on water traffic and waterbirds in San Francisco Bay will not only help inform the management decisions of local institutions and agencies — but it also will contribute to our knowledge of wildlife science in general, and help us all discover new knowledge about San Francisco Bay’s ecosystem and natural resources.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information:

References to non-U.S. Department of Interior (DOI) products do not constitute an endorsement by the DOI.

* DOI and USGS link policies apply.