Topic · 4 posts
El Niño and La Niña, and what the Pacific’s big swings mean for West Coast shellfish, starting with our 2026-27 series.
Southern California coastal water had its second-warmest September since 1981, September sea level from San Francisco south topped 1997 (uncorrected for air pressure), and heatwaves off Morro and Tomales were still going on October 20th. It also covers the Kelvin wave and Vibrio.
About a third of Pseudo-nitzschia seriata-group blooms at California piers were followed within eight weeks by at least 0.5 ng/mL of domoic acid in seawater. El Niño indices added no detectable forecast skill beyond local ocean state, in tests that could only catch a large gain.
In past El Niño winters, rule-implied rain-closure exposure rose clearly at only one of five California growing areas tested, and strong eastern-Pacific winters were close to all or nothing. What the literature says, what 75 years of rainfall show, and what to watch this winter.
The central equatorial Pacific is warmer for the time of year than in any year since 1950 on NOAA's current index, while the North Pacific runs cool. The first post in our El Niño series covers what we measured, what past events can tell growers, and what they can't.