San Francisco Bay is more than the geographic feature that defines our region. It is home to hundreds of types of fish, birds, and other wildlife. It provides food (it once provided a lot more). It’s an aquatic mood stone that goes from slate grey on a cloudy day to sparkling emerald and sapphire on a sunny day. (And, yes, it smells kind of bad sometimes, too.) Unknown by many, it the largest estuary on the west coast of North America, in a league with Chesapeake Bay on the east coast and the Mississippi Delta on the gulf coast. Whether riding on a bike or watching birds or having a BBQ, we are fortunate to have this amazing place in our backyard. And we’re not the only ones: millions of birds use the Bay as a critical stopover point when the migrate along the Pacific Flyway each year. They get food and shelter from the saltmarshes and tidal mudflats. But these places are under threat, not just from sea level rise but also from invasive plants. Back in the last century, well-meaning engineers planted Atlantic cordgrass for erosion control. Then it began to spread and damage marshes. Since 2005, the Coastal Conservancy’s Invasive Spartina Project has used airboats, genetic testing, sophisticated GIS, and a lot of hard work to push back the invasive cordgrass. Learn about how hometown heroes are doing their part to address the global biodiversity crisis.