Text by Victoria Schlesinger; images by Jane Kim.
SPOTLIGHT SPECIES: OCHRE SEA STAR
Seeing stars
In 2013, biologists began to notice that sea stars—more than 20 species of them, eventually—along North America’s Pacific coast were suffering from an illness that caused them to disintegrate. Literally, limbs fell off and creatures dissolved away. The illness, dubbed sea star wasting disease, ravaged populations, including the ochre sea star (Pisaster ochraceus).
But that initial die-off was followed by huge recruitment pulses. Meaning, lots of ochre sea star larvae settled in tidepools and began to grow. They are so itty-bitty, it’s roughly a year before scientists can even see them to count them. Sea stars’ recovery has been mixed along Bay Area coastlines, says Sarah Cohen, a biology professor at San Francisco State University. Some have returned. Others not so much. But the infections have mostly subsided.
This summer scientists concluded the bacterium Vibrio pectenicida was killing sunflower sea stars. More study will determine its impact on other sea star species.
Bionic butterfly
This overwintering season, sometime between October and March, when monarch butterflies (Danaus plexippus) settle in Santa Cruz, at least two dozen will be outfitted with tiny transmitters—weighing .06 grams and attached with eyelash glue—powered by solar panels. For this new experiment studying the beleaguered western monarch population, Xerces Society researchers invite the public to follow along and detect tagged monarchs through the Project Monarch app. Scientists hope to learn more about the monarchs’ migratory routes to better protect them.
The nose has it
Male surf scoters (Melanitta perspicillata) have a fantastic schnoz, or, technically, a bill, but really it looks like a great, lumpy, fire-hued nose, and it has captured human hearts. It gets attention from the lady scoters, too. The colorfully snooted male swims back and forth, dipping and shaking his honker in a female’s direction. Courtship begins along California’s coast, where the diving ducks winter, before the pair flies to Alaska and Canada to breed. But since 1989, the number of scoters wintering in the Bay has been declining, according to the 2025 San Francisco Bay State of the Birds report.
Winter feast
Manzanitas—those red-barked, smooth-skinned, serpentine-limbed, quintessential California shrubs that can sometimes grow tree-high—are food banks during the Bay Area’s winter. In 2015 some 105 manzanita taxa were known; in the decade since, that number has climbed to 108, thanks to how easily they hybridize and a lot of research. The common manzanita (Arctostaphylos manzanita) has six subspecies. They supply bees and hummingbirds with nectar and host potentially dozens of species of moths as larvae during winter, including the elegant sphinx moth (Sphinx perelegans).
State of flow
Freshwater flooding in winter needs a rebrand. The dire consequences of rivers and creeks overflowing their banks in the Bay Area catch the headlines, while in fact over the last 94 years, less and less fresh water is emptying into the San Francisco Estuary, according to the 2025 State of Our Estuary report. Water has increasingly been siphoned off for all manner of human needs. That means floodplains aren’t getting a regular dose of nutrients, groundwater isn’t recharging, and the quiet, low-saline shallows that young creatures, especially salmon, depend on are missing.
Bro-cation
You’re not imagining it. Over the past decade, California sea lions (Zalophus californianus) have increasingly been swimming through San Francisco Bay and up the Sacramento–San Joaquin River into the Delta and hanging out for the winter. Carp and sea bass lure them, and the haul-out spots convince them to stay. It’s the adult and subadult males you’re seeing, recuperating after the summer breeding season in Southern California’s Channel Islands. If you encounter a sea lion in the Delta, calmly retreat to another spot on the water.
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