San Francisco Bay Area

10,000 BCE - present

The San Francisco Bay Area refers to the region encompassing the San Francisco, San Pablo, and Suisun Bay estuaries. It serves and feeds from a connected system of creeks and rivers, reservoirs, marshes, and lakes. The bay area is among the six most important hotspots for biodiversity in the United States, home to over 90 species of flora and fauna. Among these are shore, marsh, and upland birds, marine and land mammals, reptiles, and amphibians. Many of these are endangered, including the salt marsh harvest mouse, the pacific herring, the pygmy blue butterfly, and the river otter. Invasive species have disturbed the Bay Area ecosystem for centuries. Asian kelp contributes to beach erosion and damages other marine culture. What remains of the salt marshes work to filter pollutant debris and sediment as well as serve as habitat for tidal marsh wildlife. However, these marshes are eroding further from an overpopulation of striped shore crabs. Extensive residential spread has vastly transformed the Bay area, which now contains roughly 7.75 million people throughout its nine counties. Resultant deforestation and increased pollution contribute to warming air and water temperatures. The rising climate affects all other aspects of the bay area’s health. Wildlife migratory patterns are disrupted, water levels are rising, and vegetation cannot be sustained.

The territory of San Francisco falls within the ancestral homelands of the Ohlone, Ramaytush, and Muwekma peoples.

Territorial recognition: https://native-land.ca/

Most Pressing Issues

Deforestation

Huge redwoods historically towered over much of the northern California landscape. In the San Francisco Bay area, these forests condensed the regional fog to keep temperatures low and rainfall consistent. Deforestation in the bay area has led to soil erosion, rising average temperatures, and loss of habitat for native wildlife. Although redwood forests are now protected, logging is an issue which continues to harm California ecosystems today.

Pollution

In the mid-19th century, the gold rush introduced excessive mining waste into the bay area. The crystal clear water became muddy with gold washings and quickly spread to surrounding rivers and streams. Storm water waste is presently the largest source of pollution in San Francisco. Since the 1950s, the shoreline has been reduced due to garbage dumps and household waste.

Water levels and shoreline

Rising water levels in the San Francisco Bay area are caused by a handful of factors and affect the health of the ecosystem in many different ways. Causes of seal level rise include but are not limited to residential and industrial pollution, climate change, and tidal fluctuation. The rising water levels are also detrimental to wetland rehabilitation efforts, as freshly restored wetlands are fragile. Additionally, sea level rise accelerates cliff retreat as bigger waves hit the land at faster and stronger rates. As cliff retreat advances, the wildlife dependent on these areas are experiencing major habitat loss.

Wildlife decline

Wildlife populations in the San Francisco Bay area have long struggled to stay alive due to centuries of overhunting. Many of these species, such as beaver, otter and marten were highly valuable during the fur trade in the early 1900s. These animals, along with woodland creatures including racoon, badgers and skunks, were targeted for their pelts only. As described in early settler journals, whales were also excessively pursued, and later shrimp and pacific salmon. Recently, habitat destruction is the primary risk that wildlife populations in the bay area face. This is the case for the Salt Marsh Harvest Mouse and the bald eagle.

How You Can Help

Save the Bay

Save the Bay is a nonprofit organization working to rehabilitate and improve the San Francisco Bay Area water quality and wildlife populations. Founded in 1961, the organization does much to protect the land from development and restore it to its natural state.

San Francisco Bay National Society

The San Francisco Bay Wildlife Society seeks to nurture in the public a sense of understanding, appreciation, and stewardship of the San Francisco Bay National Wildlife Refuges, their natural and cultural history, and to conserve, preserve, and restore bay lands as essential wildlife habitat.

The Marine Mammal Center

The Marine Mammal Center works to rescue and rehabilitate marine mammals in the San Francisco Bay area, research the behavioral patterns of these animals, and educate the bay community on the future of global ocean conservation. The Marine Mammal Center is composed of a 1,300 volunteer network and is open to public visitation.

Sources:

“What are California Marine Invasive Species?” California Department of Fish and Wildlife, May 10, 2022.

“Marine Mammals of the Bay Area,” San Francisco Bay Wildlife Info.

“Mammals of the Bay Area,” San Francisco Bay Wildlife Info.

Renee Cormier and Melissa Pitkin, Pocket Guide to Birds of San Francisco Bay, (Petaluma, CA: Point Blue Conservation Science), 2008.