Illustrations by Jane Kim; research and writing by Bay Nature staff.
Gulls begun wild
Congratulations: you’ve taken your first flight and made it out on your own on a jagged rocky Farallon island, 30 miles from the soft living of the mainland’s garbage piles. You grew up surrounded by thieves and predators; that’s how you honed your wit and courage. By early fall, fledgling western gulls (Larus occidentalis) are nearly grown and fully independent: foraging along the coast, skimming the sea for fish, and winging over to San Francisco to catch the end of baseball season. Western gulls born in Santa Cruz or Bodega Bay have been seen returning to their parents as late as September for an extra meal. But not those from the Farallones, the largest western gull nesting colony on earth and the incubator of what may be our toughest seagulls.
A Christmas Coral
While not much marks the passage of time in the deep sea, the majestic, slow-growing Christmas tree coral (Antipathes dendrochristos)—one of the 30-odd coral species known to live in the freezing depths off California’s coast—is arguably always in holiday mode. In 2012, scientists collected a piece from a beautiful specimen in 300 feet of water some 20 miles southwest of Point Reyes. A bright-orange rosy rockfish was peering out from underneath the “tree,” which measured 10 feet across; a similar-size coral specimen was estimated at over 140 years old. Until 2012 this species had only been seen in Southern California. Scientists gave it its name in 2005 because it “resembled a multicolored, snow-flocked Christmas tree, replete with ornaments of barnacles, worms, shrimps, and crabs.”
Ver-millions
The cold regions of the Pacific are awash in biodiversity, but not usually in color. At least we have the vermilion rockfish (Sebastes miniatus), a resident of California’s rocky offshore reefs that shines through the depths in a radioactive red-orange it owes to zooplankton in its diet. Vermilion rockfish can be on the shy side; they’re a popular catch in both recreational and commercial fisheries, with about 220,000 pounds landed commercially in 2023. In our area, the fish spawn from September through December. Vermilion rockfish give birth to live young—sometimes more than one million larvae per mother.
Sharktoberfeast
Summer’s end is a time for return and reunion: friends come home from vacation, kids go back to school, and the largest adult great white sharks (Carcharodon carcharias) swim to their famed hunting grounds around the Farallon Islands. They arrive in time to overlap with immature elephant seals, which attempt to haul out on pocket beaches. After packing on the calories between September and November, the sharks will leave California for the “white shark cafe” in the open Pacific. Farallones sharks are mostly repeat visitors: males show up every year, females alternate years. If a cage dive isn’t for you, shark season energy peaks on land with Sharktoberfest events around the Bay Area.
Fancy fringe
“Of all land plants, the palm is the most distinguished,” English botanist E.J.H. Corner once wrote. Where the land ends, you’ll find classy sea palms (Postelsia palmaeformis), technically annual algae, that grow in clumps like an epaulet fringe on the rocky coast. Sea palms reach up to two feet in height and turn a rich caramel color in the summer and fall as they drop their spores. The crashing waves are doing them a favor, by battering other species out of the way. The spores stay close, which renders populations more vulnerable to threats like marine heat waves and overharvesting. Eventually winter storm surges best the mature palms, ripping them out by their holdfast roots and clearing the rocky coast, until the spores shoot up in early spring.
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The eyes have it
The oceans are chock-full of zooplankton. Which particular plankton, however, changes constantly. Colder water and south-flowing currents bring Arctic species to our coast, while warmer water and north-flowing currents bring more temperate species. One of the temperate critters is Ditrichocorycaeus anglicus, a kind of tiny crustacean known as a copepod. Most copepods have a light-detecting eyespot, called an ocellus, but nonetheless hunt their phytoplankton prey by smell and touch. D. anglicus, though, has a lens-like structure built into its carapace. Experiments have shown that D. anglicus hunts better in the light than in the dark, suggesting it can do something many copepods can’t: use its eyes to see.
