Fish are falling from the sky in parts of San Francisco, and a boom in coastal anchovy populations is to blame.
Reddit user sanfrannie posted earlier this month that about a dozen 8-inch silver fish “rained down from the sky” onto their friend’s roof and back deck in the Outer Richmond. Several other users commented with similar experiences — one person said they “heard a whoosh sound behind me and heard a massive splat” before seeing fish scattered on a nearby driveway. Another commented that they “almost got hit by a fish waiting for a bus” in the Castro, and a third person said they assumed “a band of roving kids were doing a Tik Tok sardine-throwing challenge on a roof somewhere” after seeing several fish fall onto an Outer Richmond sidewalk.
Local fishers and researchers are blaming seabirds that, because of an explosion in the anchovy population off the coast of the Bay Area, now have more fish than they know what to do with.
“From Half Moon Bay to Point Reyes, people are telling me they’ve never seen bait this thick,” said Larry Collins, president of the San Francisco Community Fishing Association. “I heard stories just last week from guys who said that the water out there was just covered with thousands of birds, and the birds were just sitting on the water with anchovies in their mouths because they can’t eat anymore.”
Jim Ervin, retired laboratory analyst at San Jose’s Environmental Services Department, wrote in a June 11 blog post for UC Davis’ Otolith Geochemistry & Fish Ecology Laboratory that “the anchovy population just exploded in Lower South SF Bay.”
“The monthly totals in April and May were 29 and 52, respectively,” the post says. “The total number leaped to over 2,600 for the June trawls. This is the second-highest monthly total we have ever seen.”
Adam Ratner, associate director of conservation education at the Marine Mammal Center in Sausalito, attributes the phenomenon to normal patterns of upwelling, a process in which cold, nutrient-dense water rises from the ocean depths, replacing warmer water at the surface.
“The water temperatures right now do appear to be colder than normal, and this has provided some much-needed food for animals such as anchovies, seabirds and marine mammals,” Ratner said. “It is unclear how long this burst of cold water will last, and we know with climate change that the trend is pointing towards warmer water temperatures becoming the norm, but for the time being, this appears to be providing some additional support for fishing communities, migrating whales and our local sea lions.”
According to Collins, the water this year is the coldest local fishermen have seen in a long time, and the anchovies are a testament to that.
“It’s just totally healthy ocean out there right now. I heard guys telling me about pelicans that, instead of diving to fill their mouths up, they’re just skimming the water and getting full mouths of anchovies,” Collins said.
As far as the fish raining onto city streets, birds like these pelicans are almost certainly to blame.
“The anchovies are in pretty big numbers right now, and are pretty close to shore,” said Whitney Grover, interim deputy director at the Golden Gate Audubon Society. “So we’re experiencing a lot of these seabirds fishing, and then if they fly back over the land on the way to wherever they’re going, sometimes they drop fish.”
Grover said that some bird species like the double-crested cormorant prefer to stay more inland, near freshwater lakes, but will travel to the coast when there’s a large number of fish to feed on. Brown pelicans also tend to fly longer distances on daily foraging routes. Birds like these could explain people having to dodge falling fish in neighborhoods like the Castro.
“I could see them going to Ocean Beach and picking up some anchovies, then flying right over San Francisco and over the Castro to go into the bay,” Grover said.
The boom in anchovies has also brought in large numbers of marine mammals that feed on forage fish. So while things might get a little slimy if you’re planning on hitting the waves, it’s the perfect time to try out some whale watching.
