Kolkata: El Niño has strengthened and is expected to remain strong through the July–September season, the Indian National Centre for Ocean Information Services (INCOIS) has said in its latest report published on August 15.
“The persistence of El Niño through the upcoming seasons is expected to influence ocean conditions across the North Indian Ocean. Higher sea surface temperatures (SST), increased upper ocean heat content, stronger stratification, and widespread marine heatwaves may affect marine ecosystems, fisheries, and coastal environments,” the report said.
The warming conditions associated with El Niño are likely to result in a modest decline in small pelagic fish landings (Indian Oil Sardine and Indian Mackerel) and a possible reduction in the average size of these species during the upcoming fishing season. “Prolonged warming and associated changes in ocean productivity and fish habitats may alter the distribution and availability of commercially important fish species,” INCOIS said.
Marine heatwave conditions are already widespread across the Northern Indian Ocean, with moderate to extreme marine heatwaves observed over substantial portions of both the Arabian Sea and Bay of Bengal. The persistence of warmer ocean conditions may increase thermal stress on coral reef ecosystems and the likelihood of coral bleaching during prolonged marine heatwave events, INCOIS noted.
Changes in ocean temperature and marine productivity associated with persistent warming may affect fishing conditions and the distribution of potential fishing zones during the upcoming seasons. “Warmer ocean conditions may influence the background environment for extreme weather events, while coastal regions may remain vulnerable to localised erosion, flooding and storm surge impacts during severe weather episodes,” the report said.
INCOIS has urged fishermen, maritime operators, coastal communities, tourism stakeholders and disaster management agencies to closely monitor its ocean services throughout the forecast period, including Potential Fishing Zone advisories, Ocean State Forecasts, High Wave Alerts, Swell Advisories, Storm Surge Forecasts and Coastal Inundation Services. “INCOIS will continue to provide Marine Heatwave Advisory System (MAHAS), Ocean State Forecasts (OSF), Coral Bleaching Alerts and Harmful Algal Bloom (HAB) advisories to support preparedness and decision making during the evolving El Niño conditions,” the agency said.
According to INCOIS, El Niño refers to the warming of the eastern Pacific Ocean associated with the positive phase of the El Niño–Southern Oscillation (ENSO). A prevailing El Niño condition in the Pacific Ocean has an adverse effect on the Indian summer monsoon rainfall and, thereby, on the economic well being of the country. El Niño is also found to cause stronger and prolonged marine heatwaves in the northern Indian Ocean, damaging the ecological balance and coral reefs and causing significant losses to the fishery industry.
“Thus, monitoring the El Niño condition and predicting its further evolution with sufficient lead time is of prime importance for better preparedness and policymaking. Beyond its influence on monsoon rainfall, El Niño can significantly alter ocean conditions across the Indian Ocean through changes in sea surface temperature, upper ocean heat content, ocean circulation, marine heatwaves, and marine ecosystem productivity. These changes can influence fisheries, coral reef health, coastal hazards, and maritime activities, making ENSO outlooks valuable for a range of operational ocean services,” it said.
“From August 2026 onwards, through most of the forecast period to March 2027, El Niño is expected to remain the dominant ENSO phase, with probabilities ranging from 80 to 98 per cent. ENSO neutral conditions are projected to be the second most likely phase, with probabilities of 5 to 20 per cent during August 2026 to March 2027, increasing to around 45 per cent by April 2027, followed by La Niña, which remains the least probable phase with probabilities of less than 2 per cent through April 2027,” the report stated.
(IANS)
