Humboldt Bay is a natural bay and a multi-basin, bar-built coastal lagoon located on the rugged
North Coast of
California, entirely within
Humboldt County. It is the largest protected
body of water on the
West Coast between
San Francisco Bay and
Puget Sound, the second largest enclosed bay in California, and the largest port between San Francisco and
Coos Bay,
Oregon. The largest city adjoining the bay is
Eureka, the regional center and county seat of Humboldt County, followed by the college town of
Arcata. These primary cities together with adjoining unincorporated communities and several small towns comprise a Humboldt Bay Area total population of nearly 80,000 people, which accounts for nearly 60% of the population of Humboldt County. In addition to being home to more than 100 plant species, 300 invertebrate species, 100 fish species, and 200 bird species, the bay and its complex system of marshes and grasses support hundreds of thousands of migrating and local shore birds. Commercially, this second largest
estuary in California houses the largest
oyster production operations on the West Coast, producing more than half of all
oysters farmed in California.