The San Francisco Bay–Delta Estuary drains 40 percent of California land.

The San Francisco Estuary Institute, along with local government agencies and interested citizens, has developed the Bay Area EcoAtlas, a Geographic Information System (GIS), to provide public access to well-validated, regionally consistent information about the ecological resources of the San Francisco Bay Area.

Many kinds of information from numerous sources are being integrated in this GIS to form a comprehensive picture of the environmental past, of the present, and of change. The EcoAtlas provides the most detailed regional views of past and present ecological conditions now available. It is also a spatial template for viewing possible scenarios for environmental management and a geographic index for environmental data and their sources. The high level of accuracy and detail was made possible largely by over 200 Bay Area residents who have contributed information and over 10,000 hours of their time.

The Native Landscape View (c. 1770 - 1820) is a composite picture based on information gleaned from thousands of documents examined at archives throughout the region. The sources included 18th- and 19th-century maps, paintings, photographs, engineering reports, explorers' journals, hunting magazines, and interviews with elders. Each historical feature in the map is classified according to level of certainty for shape, location, and size, based on a file of supporting information.

The Modern Landscape View (c. 1998) is based on infrared aerial photography taken during the winter of 1995 - 96. The Estuary Institute produced a series of draft versions of the modern view, which were revised by more than 100 local and regional experts during 1996 and 1998.

Now the EcoAtlas is being extended into local watersheds. Detailed pictures of current conditions and of change through time will soon be available for Wildcat Creek (Contra Costa and Alameda Counties), Miller Creek (Marin County), Nathanson Creek (Sonoma County), Permanente Creek (Santa Clara County), and other watersheds. In collaboration with local partners, the Estuary Institute is compiling information on native fish species, aquatic contaminants, local watershed boundaries, and other significant datasets.

The first version of the EcoAtlas is being used in diverse public settings for science, planning, and education. It is envisioned that anyone will be able to use it to exchange information about local and regional ecology. Planning continues to assure the accuracy of the EcoAtlas, maximize its availability to the public, and enable reputable sources to add information. The Estuary Institute will endeavor to make updated versions available as quickly and easily as possible, while maintaining interagency approval of the contents and the highest standards of science. It is hoped that the EcoAtlas will enhance the regional sense of place and purpose.

EcoAtlas paper maps and posters are available through the Estuary Institute. Curricular materials based on the EcoAtlas are being designed and tested by the West Contra Costa County School District for use in local schools. The digital EcoAtlas is currently being "beta-tested" on CD by agency and community group partners. After the beta-test and distribution plans are completed, the EcoAtlas will be released to the public on CD. The Estuary Institute welcomes partnerships to make the EcoAtlas useful for local and regional environmental planning, management, and stewardship.

For more information, contact Gabriele Marek: (510) 231-9539 or gabriele@sfei.org, or visit the EcoAtlas at the San Francisco Estuary Institute's website: www.sfei.org to view maps.

Robin Grossinger is an environmental scientist at the San Francisco Estuary Institute.