Bay Nature: The Backstory on Pacifica’s Whale Bonanza

Published in Bay Nature: October 10, 2024

In dense fog 30 miles out from the Golden Gate Bridge, the 50,000-pound humpback whale’s leap out of the water is almost totally silent, maybe 300 feet away. Its motion is as smooth and natural as an exhalation; its ribbed body arcs and cascades back into the mirrored sea. Seconds later, the only sign it was there at all is my fast-beating heart. 

Meanwhile, our boat, the research vessel Fulmar, continues motoring ahead against the swells of the San Francisco Bay. If we want to understand what that lone humpback whale means in the ocean’s broader story, we have a schedule to keep. 

For the past 20 years, scientists have been motoring transects—straight lines across the water—to count whales like this humpback, as well as anything else they see along the way, whether bird or balloon. They cast fine nets to see what small things live in the deep; they measure variables like salinity and temperature. All to produce an annual health check for this part of the eastern Pacific Ocean. These cruises—known as the Applied California Current Ecosystems Studies, or ACCESS—are a collaboration between the Petaluma-based nonprofit Point Blue Conservation Science, the U.S. National Oceanic and Atmospheric Administration, and the Cordell Bank and Greater Farallones national marine sanctuaries. Through these surveys, scientists have watched the ocean go through seismic shifts over the last two decades. And one of the most marked changes they’ve observed is how humpback whales shifted towards land after the 2014–2016 marine heatwave, often called the Blob. 

...the most marked changes they’ve observed is how humpback whales shifted towards land...

It’s a change unmistakable to not only marine biologists out at sea, but citizens and scientists standing on solid ground. This year in particular has been a “banner year” for humpback whales, says Bill Keener, a marine biologist with the Marine Mammal Center, a Sausalito-based nonprofit. At places like Pacifica’s pier, thousands of people have witnessed the whales over the last few months—surfacing their smooth backs, lunging, diving, bubble-feeding—sometimes in unprecedented numbers, sometimes with tens of whales gathering at a time.

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