Calcium carbide, found in these containers, is known to produce acetylene gas upon contact with moisture, which is highly flammable.
Published Nov 15, 2025 | 3:00 PM ⚊ Updated Nov 15, 2025 | 3:00 PM
MSC ELSA 3 sinking off Kerala coast. Credit: x.com/SpokespersonMoD
Synopsis: MSC ELSA-3 sank off Kerala in May 2025 with 640 containers, including hazardous cargo. NIO’s first survey reveal oil slicks, dead marine life, oxygen depletion, massive Noctiluca and jellyfish blooms, and confirmed petroleum hydrocarbons. About 357 tonnes of toxic nurdles have washed ashore. Meanwhile, calcium carbide containers at 3km depth pose ongoing risk. On the other hand, MSC has been accused of systemic safety failures. The full report of the impact will be out by 2026.
When the container vessel MSC ELSA-3 sank on 24 May, about 13 nautical miles off the Kerala coast with 640 containers—including 13 hazardous ones—it triggered one of the biggest environmental concerns the state has ever faced at sea.
For weeks after the vessel went down, the ocean offered only fragments of what might be unfolding beneath its churning grey surface: marine mammal carcasses here, containers washed ashore there, and plastic nurdles rolling in with the tide.
But now, the ocean has begun revealing the first signs of distress—one that raises troubling questions about chemical leakage, ecological stress, and the state’s readiness for maritime disasters of this scale.
While these findings are still preliminary, they confirm what many coastal communities had feared: the combination of heavy monsoon conditions, hazardous cargo, and subsequent pollutant dispersal has created a complex mix of ecological pressures along Kerala’s southwest coast.
A full scientific picture may still be months away, but the first reports offer enough to understand both the immediate risks and the long-term uncertainties.
The National Institute of Oceanography (NIO), which has been entrusted with environmental and socio-economic impact study, carried out its first phase of field surveys between 25 July and 21 August from onboard its research vessel Sagar Samvada.
The survey spanned 10 transects from Cape Comorin to Kozhikode, (others being Colachel, Vizhinjam, Kollam, Karunagappalli, Alappuzha, Arthungal, Kochi, and Munambam), combining visual assessment, water sampling, sonar imaging, and biodiversity tracking.
The first and most notable observation was the presence of oil slicks at the wreck site.
According to the NIO, a large patch of oil film was visible on the water surface directly above the capsized vessel.
The slick appeared to have aligned with wave directions and was drifting toward coastal regions—a typical behaviour during the monsoon when wind speeds and oceanic turbulence increase dramatically.
Fragmentation of the slick into dispersed patches was also noted, a process accelerated by heavy winds and currents.
The presence of oil in the water was not just visual.
A dead and deformed marine turtle was found at the wreck site—an early sign of potential toxicity in the surrounding waters.
Oil exposure can suffocate marine reptiles, coat their skin, and disrupt feeding and reproduction.
NIO scientists warn that early-stage mortality signals must be tracked closely, as they could point to wider impacts on marine fauna.
The monsoon-driven coastal upwelling along the southwest coast—a natural process in which deeper, colder, nutrient-rich water rises to the surface—was unusually intense at the time of survey.
Upwelling is a seasonal phenomenon, but during pollution events it can drive contaminants vertically through the water column, expanding the zone of ecological impact.
The team also detected traces of Arabian Sea High Saline Water mass, indicating strong mixing in the region.
Certain stretches, particularly off Kanyakumari, experienced wind speeds above 20 knots due to the funneling of winds through the Gulf of Mannar and Palk Bay. This combination of high winds and rough sea conditions would have likely accelerated the spread of any leaked oil or other hazardous materials.
Oxygen depletion was reported across multiple transects—especially at Kozhikode, Munambam, Kochi, and Colachel.
These areas appeared to be influenced by the naturally occurring Oxygen Minimum Zone (OMZ) in the southeastern Arabian Sea.
While low oxygen conditions are typical in deeper waters, the NIO notes that when combined with pollutants from shipwrecks, OMZs can worsen stress on marine organisms.
The survey also recorded unusual biological responses.
Gelatinous plankton—mainly jellyfish-like organisms—were found in abundance across the Kollam transect and further north.
Massive blooms of gelatinous species were detected in the coastal waters of Kochi, Alappuzha, and Kollam.
Additionally, a striking bloom of Noctiluca, a bioluminescent plankton notorious for causing green or red discoloration in seawater, was observed from Kollam to Kozhikode.
An extensive patch was particularly visible off Arthungal.
While plankton blooms may appear visually dramatic, their ecological significance is more complex.
They often indicate shifts in nutrient availability or water chemistry, and in some cases reflect ecological disruption.
Noctiluca blooms, for instance, can lead to oxygen depletion and harm fish populations—raising questions about whether the shipwreck and resulting pollution may be influencing bloom dynamics.
The NIO emphasises that these findings constitute only early indicators.
Detailed chemical, biological, and hydrodynamic analyses are underway and will be reflected in a comprehensive first-phase report due on December 30, 2025.
The full environmental impact assessment—spanning three stages—will only be completed by July 2026.
A crucial aspect of this shipwreck is the presence of 13 containers classified under IMDG Class 4.3—materials that react dangerously with water.
Calcium carbide, found in these containers, is known to produce acetylene gas upon contact with moisture, which is highly flammable.
While authorities have not yet confirmed leakage from these containers, their location at a depth of roughly 3 km poses long-term uncertainties.
If breached, the reaction of calcium carbide with seawater may cause localised toxic gas pockets or chemical contamination—a scenario scientists are watching closely.
This category of cargo underscores why the NIO will model pollutant dispersion, track seasonal variations, and identify both short- and long-term ecological risks.
Separately, the Kerala State Pollution Control Board received the lab results of two deep-sea water samples collected by the Indian Coast Guard on 25 May, just a day after the shipwreck.
These samples, labelled 251330 and 251530, were analysed for pH, conductivity, heavy metals, and petroleum hydrocarbons (TPH).
While pH and conductivity levels aligned with typical marine values, the presence of petroleum hydrocarbons—0.08 mg/L and 0.055 mg/L—confirmed measurable oil contamination in the deep sea surrounding the wreck.
Though these concentrations may appear low, their importance lies in the fact that oil had already entered the marine environment within 24 hours of the incident.
The Board noted that comparing these results with standard coastal water quality norms is not meaningful because the samples were collected offshore in deep sea conditions.
The Pollution Control Board on 21 October informed the National Green Tribunal that it is undertaking periodic sediment sampling to assess heavy metals and microplastics.
However, the Board stressed that the full environmental and socio-economic impact can only be determined after the NIO completes its final reports covering all phases of the study.
Besides oil and hazardous cargo, one of the most visible consequences of the shipwreck has been the widespread deposition of plastic nurdles—small pellets used in manufacturing—along the beaches of Kollam and Thiruvananthapuram.
These nurdles, lightweight and buoyant, spread rapidly along the coastline in the weeks after the wreck.
Between 24 June and 9 October, approximately 357.6 tonnes of nurdles were collected and transported to Kollam port.
Their removal was coordinated through a massive clean-up effort involving the salvaging company, local volunteers, and multiple government departments under the guidance of the Kerala State Disaster Management Authority, which had developed a beach clean-up protocol specifically for nurdle contamination.
Despite the clean-up, scientists warn that nurdles are among the most harmful forms of marine plastic pollution.
They absorb toxic chemicals, are mistaken for food by fish and seabirds, and break down into microplastics.
The long-term impact on Kerala’s marine food chain—including fish and shrimp ready for export—will only be known after detailed chemical analysis and the completion of NIO’s long-term monitoring.
The incident has pushed the state to accelerate its preparedness frameworks.
Kerala has contracted Environ Software Pvt. Ltd. to prepare an Oil Spill Contingency Plan (OSCP).
The draft OSCP is expected within eight months from the signing of the agreement on 20 August, 2025.
The plan will focus on early warning systems, risk identification, ecological recovery strategies, and institutional reforms to improve response to future maritime incidents.
Amid mounting evidence of environmental damage from the shipwreck, a new investigative report by Greenpeace South Asia, published on 13 November, has sharpened the spotlight on the world’s largest container carrier, the Mediterranean Shipping Company (MSC).
‘Below Deck: The Truth Beneath What You Sea’ examines MSC’s global operations between 2015 and 2025 and alleges a pattern of systemic safety failures, opaque liability practices, and regulatory evasion.
The report argues that the sinking of MSC ELSA 3 in May 2025—an ageing, Liberian-flagged vessel carrying fuel, hazardous cargo, and plastic pellets—was not an isolated tragedy but part of a decade-long trend.
It highlights repeated incidents across MSC’s fleet, including container fires, cargo losses, collisions, and oil spills, many aboard older ships operating in Global South waters.
According to Greenpeace, MSC has routinely deployed ageing vessels under flags of convenience on routes with weaker enforcement, while relying on international liability-limitation regimes and confidential settlements to minimise accountability after accidents.
This practice, the report says, has left coastal communities—from Kerala to the North Sea—bearing the environmental and economic costs.
The findings, drawn from port inspection records, court filings, and verified media sources, call for stronger global regulation, transparent remediation, and equitable compensation frameworks as scrutiny intensifies over MSC’s environmental governance.
The shipwreck incident has thus become a slow-moving ecological crisis whose full scale Kerala has yet to grasp.
With three phases of NIO studies in the pipeline and periodic monitoring by state agencies, Kerala’s assessment of the MSC ELSA-3 disaster is still evolving.
The preliminary findings, however, already underscore the complexity of the environmental impacts—from toxic cargo risks and oil contamination to altered biological activity and the spread of massive amounts of plastic nurdles.
The shipwreck has also exposed the gaps in disaster preparedness and the need for a robust regulatory framework for maritime safety, environmental liability, and emergency response.
As Kerala awaits the comprehensive scientific reports due in 2026, the incident serves as a stark reminder of the fragile balance in its coastal ecosystems—and the high cost of disruptions in its waters.
(Edited by Amit Vasudev)
