Satellite maps published by NASA's Earth Observatory on August 10, 2026, compared monthly average chlorophyll-a concentrations for June 2025, when conditions were neutral, with June 2026, as El Niño was strengthening. Data came from the Ocean Color Instrument on NASA's PACE satellite. The largest difference appeared in the central Pacific near the equator due north of New Zealand, where the June 2026 concentrations were substantially lower.

Oceanographers Matthew Kehrli and Graham Trolley of the Ocean Ecology Laboratory at NASA's Goddard Space Flight Center said the change is expected: weakening equatorial trade winds deepen the warm surface layer and suppress upwelling of cool, nutrient-rich water that fuels phytoplankton. They anticipated that differences in the central Pacific would become more pronounced as El Niño progresses, though they noted outcomes depend on trade-wind behavior. Reduced phytoplankton can limit food for zooplankton, fish, seabirds and marine mammals.

The observatory reported that Peru's Ministry of Production repeatedly suspended anchovy fishing in 2026, and that pelicans had been seen in Peruvian ports and urban areas seeking food. NOAA's Climate Prediction Center expected the El Niño to keep strengthening through the end of 2026, with a 97 percent chance of lasting through early Northern Hemisphere spring 2027.