Right now, the Tiburon peninsula and Richardson Bay within San Francisco Bay are alive with Pacific herring, a silvery fish that spawns in the winter and early spring, provoking a feeding frenzy among wildlife. We witnessed the spectacle yesterday alongside Bay Nature Editorial Director Eric Simons, who just wrote a great story about the return of herring to the Bay on Bay Nature Online. As you can see from the photo above, ducks are massing in great numbers out on the bay to feed and rest.

Above, gulls feed on roe deposited on rocks and submerged vegetation in Tiburon.

Pacific herring are a vital food source for dozens of species of birds, marine mammals, large fish and other wildlife in the Bay and along the Pacific Flyway from Alaska to central California. Herring and its roe (eggs) are energy-rich, aggregated, and found in predicable locations in estuaries and quiet embayments with just the right combination of conditions for spawning. In fact, herring spawn on just a tiny fraction of the California coast, and San Francisco Bay is the most important spawning area south of British Columbia. The circles on the map below indicate the relative sizes of herring spawning populations south of Alaska:

The tens of thousands of ducks, gulls, and other wildlife surrounding us yesterday reminded us of the importance of our campaign to protect and sustain herring in San Francisco Bay and at other, smaller yet still important, spawning areas in California. We are pushing for habitat stewardship and responsible fishing practices in order to sustain this vital resource for wildlife into the future.

Herring will be spawning in the Richardson Bay and other areas through February, and the birds and other wildlife are out there enjoying it. It’s a great time to see wildlife on the bay.