Super El Niño Turns Pacific Waters Bluish as Plankton Decline Accelerates
NASA satellite data show the equatorial Pacific has become noticeably bluer this year, reflecting a sharp drop in green phytoplankton caused by the ongoing Super El Niño.
NASA’s latest satellite observations indicate that the equatorial Pacific is turning a deeper blue as the Super El Niño intensifies, a change visible in time-lapse images that contrast one outlet state with the greener waters of 2025. The loss of colour is linked to a collapse of photosynthesising plankton, which normally give the ocean its green shade by thriving on upwelled, nutrient-rich water. Weakening trade winds during El Niño have halted this upwelling, leaving the surface waters nutrient-poor and causing the plankton to starve.
NOAA projects an 83 % probability that this will be the most powerful El Niño since records began in 1950, with sea-surface temperatures in the eastern Pacific already 1.7 °C above average and likely to rise further. The PACE satellite, launched in 2024, captured the colour shift in hyperspectral detail, while Kelvin waves detected earlier this year have already raised sea levels by up to 1.3 feet near South America. Researchers caution that the decline in plankton could trigger cascading effects throughout the marine ecosystem, displacing fish and other wildlife that depend on these microscopic producers.
Why it matters
The blue-shift signals a major disruption of ocean nutrients, threatening marine ecosystems and global climate patterns.
How this story developed
- Aug 31 UN warns that a record-breaking El Niño could trigger worldwide extreme weather
- Sep 3 UN says the El Niño is expected to remain in place until February 2027.
- Sep 7 Britain announced cuts of more than 80 % to bilateral aid in eight African states.
- Sep 7 UK models show a higher likelihood of stormier, wetter conditions during autumn and winter.
- Sep 9 The contiguous United States experienced its warmest June-August period on record, with an average temperature of 74.4°F, according to NOAA.
- Sep 10 August 2026 set a new all‑time monthly heat record and drought drove the two biggest western water reservoirs to their lowest historic levels.
- Sep 21 The system, now classified as a hurricane, is positioned about 270 miles south-southeast of Manzanillo and 190 miles south-southwest of Zihuatanejo, with sustained winds of 80 mph. Forecasts suggest it could reach major-hurricane strength by Tuesday and maintain a trajectory offshore while dumping 4-8 inches of rain across Guerrero and Michoacan through Thursday. Tourist hubs such as Acapulco, Puerto Vallarta and Guadalajara may experience rough seas and gusty conditions, and the moisture could trigger flash-flood threats in the U.S. Southwest later in the week.
- Sep 23 Polo intensified to Category 5 with maximum sustained winds of 175 mph.
- Sep 24 Authorities opened shelters and deployed thousands of military and Red Cross personnel to assist affected communities.
- Sep 29 Probability estimates now place a greater than 90% chance that the El Niño will remain very strong through February 2027.
- Oct 2 Manila Water Philippine Ventures is stepping up its water-supply safeguards after PAGASA projected a very strong El Niño that could last until the first quarter of 2027.
- Oct 7 The Department of Agriculture in Bicol rolled out a major aid package for farmers and fishers ahead of the El Niño.
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