Introduction
The next challenge for India’s fishing industry may be developing far beyond the coastline. As El Niño strengthens in the Pacific Ocean, rising sea temperatures could affect marine ecosystems across the northern Indian Ocean, putting commercially important fish such as Indian oil sardine and Indian mackerel under pressure.
India’s fisheries sector has received a specific warning from the ICAR-Central Marine Fisheries Research Institute (CMFRI): Indian oil sardine availability could decline in 2027 if the projected ocean warming occurs. The Indian National Centre for Ocean Information Services (INCOIS) has also warned of potential reductions in sardine and mackerel catches as fish respond to changing marine conditions. <Cite refs={[“turn589289search0″,”turn589289search4”]}/>
This does not mean a nationwide fish shortage is inevitable. However, the warning raises important questions about future fish landings, coastal livelihoods and the availability of affordable seafood.
How Does El Niño Affect Marine Ecosystems?
El Niño is a climate phenomenon characterised by unusually warm surface waters in the central and eastern equatorial Pacific. It changes atmospheric circulation and wind patterns, which can influence ocean conditions far beyond the Pacific.
One important process affected by ocean warming is upwelling. In upwelling regions, winds bring colder, nutrient-rich water from deeper layers towards the surface. These nutrients support phytoplankton, microscopic organisms that form the foundation of many marine food webs.
When warming weakens or alters upwelling, nutrient availability and plankton production can change. This may affect the food available to fish, their growth, reproductive success and survival during early life stages.
The effects are particularly well documented in the Peruvian anchoveta fishery. A study published in the ICES Journal of Marine Science in December 2025 examined historical ocean and ecosystem conditions and found that major El Niño events in 1982–83 and 1997–98 disrupted the timing between plankton availability and the early feeding stages of anchoveta larvae. Such mismatches can reduce larval survival and contribute to lower fishing yields. <Cite refs={[“turn589289search1”]}/>
The Indian Ocean has different oceanographic conditions, so the effects cannot simply be copied from Peru. Nevertheless, the research demonstrates how changes in temperature and food availability can influence fish populations.
Why Are Indian Oil Sardines at Risk?
Indian oil sardine (Sardinella longiceps) is an important small pelagic fish for India’s marine fisheries, particularly along the southwest coast. It supports fishing livelihoods and supplies fish to local markets and consumers.
In July 2026, CMFRI Director Grinson George warned that El Niño-related warming could intensify marine heatwaves and affect oil sardine availability in 2027. According to the institute’s assessment, the warming influence was expected to strengthen between October and December 2026, with potential effects reaching the northern Indian Ocean around April–May 2027. <Cite refs={[“turn589289search0″,”turn589289search9”]}/>
The warning is significant because oil sardine populations respond to environmental conditions that influence spawning, recruitment and food availability. Recruitment refers to the process through which young fish survive and enter the population available to the fishery.
If warming affects egg development, larval survival or the availability of plankton, fewer young fish may survive to later stages. Changes in ocean conditions can also alter where sardines gather, making them harder to locate in their usual fishing grounds.
However, the scale of any decline will depend on how marine conditions develop and how fish populations respond. A projected risk should not be treated as a confirmed reduction in the 2027 catch.
Could Indian Mackerel Catches Also Decline?
Indian mackerel (Rastrelliger kanagurta) is another commercially important small pelagic species found in Indian coastal waters. It contributes to domestic seafood supply and provides income for fishing communities and traders.
INCOIS warned in its June 2026 El Niño bulletin that the Arabian Sea and Bay of Bengal could experience thermal stress, particularly during March–May 2027. The agency identified sardines and mackerel among the species whose catches could be affected by fish moving towards more suitable habitats or by changes in recruitment. Fish may also fail to reach their usual sizes under altered environmental conditions. <Cite refs={[“turn589289search4″,”turn589289search6”]}/>
For fishing operations, these changes could mean less predictable fishing grounds, variations in catch sizes and greater uncertainty about daily landings. Even if fish remain abundant elsewhere, their reduced availability near traditional fishing areas could affect the catch obtained by local fleets.
The actual impact on mackerel will need to be assessed through ongoing observations of sea temperatures, fish distribution and landings.
What Could This Mean for Fishers and Consumers?
A decline in sardine or mackerel availability could affect several parts of India’s seafood supply chain.
For fishers, lower catches can mean reduced daily revenue even when operating costs remain similar. Traders and market vendors may face inconsistent supplies, while processors that depend on regular volumes could experience procurement difficulties.
Consumers could also feel the effects if reduced landings lead to tighter supplies in particular coastal markets. Prices, however, will not necessarily rise everywhere or by the same amount. They will depend on the scale of any catch decline, local demand, alternative fish supplies, transport costs and market conditions.
The impact could vary significantly between regions. A change in sardine availability along Kerala’s coast, for example, does not automatically mean that every Indian seafood market will experience the same shortage.
Monitoring the Ocean Will Be Critical
El Niño is not the only factor affecting marine fisheries. Long-term ocean warming, marine heatwaves, fishing pressure and habitat changes can also influence fish abundance and distribution. Separating the effects of these factors is essential for making reliable forecasts.
INCOIS has begun issuing specialised El Niño bulletins for India’s maritime sectors, while CMFRI has indicated that it will provide advisories to fishers and fish farmers. These assessments can help stakeholders prepare for changing marine conditions. <Cite ref
Regular monitoring of sea surface temperatures, plankton productivity, fish landings, catch sizes and the distribution of sardines and mackerel will be important in the months ahead. Timely information can help fishers make better-informed operational decisions and help fisheries managers respond if risks become clearer.
Conclusion
El Niño could create additional uncertainty for India’s marine fisheries as ocean temperatures rise and fish habitats change. CMFRI’s warning about oil sardine availability in 2027, alongside INCOIS concerns about sardines and mackerel, highlights the need to prepare for possible changes in fish catches.
For now, the concern is a potential risk rather than a confirmed nationwide supply crisis. How strongly it affects India’s fisheries will depend on the development of ocean conditions, fish population responses and the ability of fishing communities and markets to adapt.