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Why Are There Anchovies All Over San Francisco’s Sidewalks?

San Francisco's sidewalks are awash with anchovies, a phenomenon driven by the city's unique coastal ecosystem. These tiny fish play a crucial role in the marine food web, and their unexpected presence on land sparks intrigue about urban-wildlife interactions. What could be causing this unusual migration from sea to sidewalk? Join us as we unravel this fishy mystery.
Margaret Lipman
Margaret Lipman
Margaret Lipman
Margaret Lipman

San Francisco weather brings to mind a temperate climate with fog rolling in across the Golden Gate Bridge. The city is known for its changeable weather conditions - it can be warm and dry one minute, then cool and drizzly just an hour later. But San Francisco's latest bout of precipitation is unlike anything city residents have ever seen.

In recent days, anchovies have been spotted on San Francisco's sidewalks, rooftops, and driveways. Some people have reported seeing the silvery fish falling from the sky, leading many news outlets to report that it's "raining anchovies" in the Bay Area. While that might be a slight exaggeration, there is definitely something fishy going on – and seabirds such as pelicans are to blame.

A boom in the anchovy population has led to seabirds dropping fish from the sky onto San Francisco’s streets.
A boom in the anchovy population has led to seabirds dropping fish from the sky onto San Francisco’s streets.

Ecologists think they understand the reason for the boom, with anchovy numbers reaching their second-highest recorded level. The success of their spawning event has been attributed to a surge of cool, nutrient-dense water rising to the surface of San Francisco Bay. Full of plankton, this "upwelling" provides ideal nourishment for anchovies, and it also benefits seabirds, sea lions, whales, and other marine creatures.

It's raining anchovies!

  • Residents have reported seeing seabirds sitting in the bay, their mouths stuffed full of fish. When they fly away, some of these fish drop to the ground, sometimes with a terrific splat that makes it seem like it's raining anchovies.

  • Fishermen report that the water is the coldest they've known in years, indicating healthy ocean conditions. Ecologists don't know how long the trend will continue, as ocean temperatures are generally on the rise due to climate change.

  • Texarkana, Texas experienced fishy rain last year, but for an entirely different reason – a waterspout that deposited them miles away due to windy conditions.

Margaret Lipman
Margaret Lipman
Margaret Lipman is a teacher and blogger who frequently writes for WiseGEEK about topics related to personal finance, parenting, health, nutrition, and education. Learn more...
Margaret Lipman
Margaret Lipman
Margaret Lipman is a teacher and blogger who frequently writes for WiseGEEK about topics related to personal finance, parenting, health, nutrition, and education. Learn more...

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    • A boom in the anchovy population has led to seabirds dropping fish from the sky onto San Francisco’s streets.
      By: perfectmatch
      A boom in the anchovy population has led to seabirds dropping fish from the sky onto San Francisco’s streets.