NOAA warns strong El Niño could drive sharks and tropical species into California waters

NOAA has issued a forecast indicating a high likelihood of a very strong El Niño event this autumn, with a 63% probability of peak conditions between November 2026 and January 2027, potentially placing it among the most powerful episodes recorded. The warming of eastern Pacific waters is already setting record temperatures along the West Coast, prompting marine scientists to anticipate significant shifts in species distribution.

Professor Chris Lowe notes that juvenile great white sharks have largely vacated the San Diego nursery, while tiger, bull and hammerhead sharks are expected to appear further north. Douglas McCauley adds that tropical fish such as mahi-mahi, bluefin tuna, sea turtles and the venomous yellow-bellied sea snake could temporarily inhabit California’s coastal zones. Warmer seas may also accelerate growth of the toxin-producing algae Pseudo-nitzschia, raising concerns about domoic acid contamination in shellfish.

The altered food web could draw more whales toward shore, heightening the chance of entanglement in fishing gear. Officials stress that each El Niño is unique, but improved monitoring should help communities prepare for these ecological changes.