Alcatraz Island


La Isla de los Alcatraces, "Island of Pelicans", dubbed by Juan Manuel de Ayala in 1775 for the abundance of pelicaniforms and other seabirds, is a regionally important breeding site for seabirds on the West Coast of North America. In conjunction with the National Park Service Golden Gate National Recreation Area, we have studied the populations and productivity of seabirds on Alcatraz Island since the early 1990s (Saenz et al. 2006). Potential disturbance to breeding birds is of concern because Alcatraz is the most heavily-visited tourist destination in northern California, with well over one million visitors annually. Moreover, given its proximity to San Francisco, various activities including firework displays and the America's Cup sailboat racing may cause disturbance to the birds. Field studies focus on the breeding ecology of Brandt's cormorant and western gull. Data reports are available upon request.

Heather Robinson conducts the Alcatraz seabird research.

Heather Robinson conducts the Alcatraz seabird research.

At-sea seabird surveys

Seabird observations at sea provide valuable information about seabird distribution and abundance.  These data are coupled with hydrographic and plankton data that are collected concurrently by the ship during survey transects, which provides researchers a snapshot of ecosystem conditions and biological community structure at several trophic levels.  Farallon Institute conducts at-sea seabird surveys on two research program cruises each year, described below.  Data are available by request, and survey summary reports are available here.

Southern-Central California

We conduct at-sea seabird surveys seasonally as part of the California Cooperative Oceanic Fisheries Investigation (CalCOFI), California Current Ecosystem - Long-term Ecological Research (CCE-LTER), and Southern California Coastal Ocean Observing System (SCCOOS) programs.  These cruises take place in the Southern California Bight and along the Central California Coast.  For each cruise, a seabird observer is stationed on the bridge of the ship and records the number and species of birds seen from the ship.  The data software records the geographic position of the ship for each seabird observation and we can analyze seabird density by location.  Initiated by other agencies, Farallon Institute has been responsible for this surveying since 2008; full time series extend back to 1987. 

Central California-Oregon

We also conduct at-sea seabird surveys annually on the National Marine Fisheries Service (NMFS) Juvenile Rockfish-Ecosystem Survey off the central-northern California coast and extending up the Oregon coast.  Time series extend back to 1996, and FI observers have done the surveys since 2008.  Survey methods are the same as for the Southern California observations.

Flesh-footed shearwater. Photo copyright by  Ron LeValley .

Flesh-footed shearwater. Photo copyright by Ron LeValley.

Black-footed albatross.  Photo by Sophie Webb, spring 2017 CalCOFI cruise.

Black-footed albatross.  Photo by Sophie Webb, spring 2017 CalCOFI cruise.