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About Marin Bayland Advocates

About Marin Bayland Advocates
Marins Baylands

How You Can Help


The San Francisco Bay estuary is very different today compared to what the first Europeans saw when they arrived in 1769. Large-scale changes in the region's habitats began soon after the establishment of the first Spanish missions. Clearing of the region's oak woodlands and converting its perennial grasslands to pastures of non-native annual grasses began the process of erosion from hillsides and creek banks.

In the mid-1800s, settlers diked and filled tens of thousands of acres of tidal baylands for agricultural uses. Mining during the subsequent Gold Rush in California's Sierra Nevada Mountains sent tons of silt and debris downstream, further clogging and shrinking the wetlands surrounding the bay.

Following the Gold Rush, extensive areas of the remaining baylands were used to build ports, rail lines, and roads. Early industrial developers in San Francisco, Oakland, and other shoreline cities built many facilities on Bay fill or on land immediately adjacent to the Bay.

As development continued to the present, nearly 90% of the region's vast natural wetlands have been permanently lost. With them went critical habitat. This habitat was used for breeding, resting, and feeding by birds, fish, and other wildlife. Habitat loss and degradation have played key roles in the population declines of many species, and are the cause of many of the problems we face today. Maintaining healthy baylands helps to prevent flooding and erosion, water and air pollution, differential settlement of building foundations and roadways, and economic losses in commercial fishing.

51 species of plants and animals that occur in or near baylands are today listed under state and federal endangered species acts, including invertebrates, fishes, amphibian, reptiles, birds, mammals, and plants.