Millions of Blue 'By-the-Wind Sailors' Wash Ashore Along Pacific Coast

Millions of bright blue, jellyfish-like creatures called by-the-wind sailors (Velella velella) are washing ashore on beaches from California to Oregon and Washington. These oval-shaped zooplankton, about four inches long, use sail-like fins to drift across the ocean surface. Each organism is a colony of thousands of genetically identical zooids that perform specialized tasks such as stinging prey or reproduction. This spring, strandings are particularly heavy in the San Francisco Bay Area, where beaches appear blue from a distance, according to Jackie Sones of UC Davis' Bodega Marine Reserve. The phenomenon occurs when winds blow from west to east, often during warmer ocean conditions. A possible El Niño, predicted by NOAA, may be contributing, and scientists suspect climate change plays a role. While harmless to humans, the creatures can cause mouth and eye irritation in pets and toddlers. As they decompose, they emit a fishy odor and eventually dry to a crisp. Experts like Steven Haddock of the Monterey Bay Aquarium Research Institute note they will likely blow away within weeks.