ISRO's Oceansat-3 Detects Ocean Ecosystem Changes Amid 'Super El Niño'

ISRO's Oceansat-3 satellite has detected unusual changes in the world's ocean ecosystem, coinciding with a "Super El Niño" this year. El Niño is a periodic warming event in the tropical Pacific Ocean that recurs from time to time and affects ocean regions across the globe. This year's episode has warmed the ocean surface unusually, blocking the usual upward flow of cold, nutrient-rich water from the deep ocean to the surface.

With fewer nutrients reaching the surface layer, the growth of phytoplankton — tiny plant-like organisms in the ocean that form the base of the marine food chain — has been hindered. This has reduced chlorophyll levels in the ocean and disrupted oxygen production for marine life overall.

Two instruments aboard Oceansat-3, a satellite ISRO sent for ocean research — the Ocean Colour Monitor-3 and the Scatterometer — surveyed the ocean surface to study this. ISRO compared this June's data from the instruments with June data from 2024 and 2025, and found that chlorophyll levels in the ocean have now dropped significantly. The satellite data also confirmed that winds which normally blow from east to west are, because of El Niño, now blowing from west to east, altering ocean currents as a result.

The World Meteorological Organization (WMO) had earlier predicted that El Niño would intensify in June this year, and the Oceansat-3 satellite data has reinforced that prediction with direct ocean observations.

The findings signal that major shifts in global weather patterns and rainfall may follow, along with a decline in the ocean ecosystem — a conclusion ISRO's satellite data has pointed to for environmental organisations around the world.