Study on Keralam ELSA-3 shipwreck shows persistent nurdle pollution, evolving ecological impacts

Study on Keralam ELSA‑3 shipwreck shows persistent nurdle pollution, evolving ecological impacts In the aftermath of the May 2025 accident, the Tamil Nadu Pollution Control Board (TNPCB) initiated short‑term (rapid) and long‑term (two‑year) impact assessment studies through Suganthi Devadason Marine Research Institute (SDMRI) in Thoothukudi. The research team was tasked with quantifying immediate sediment contamination, identifying the extent of microplastic dispersion, and mapping preliminary ecological disturbances around the wreck site. Within weeks of the incident, preliminary surveys revealed unusually high concentrations of nurdles – the small beads used as a raw material in plastic production – scattered across a 200‑metre radius of the wreck..

The first rapid assessment phase focused on sediment cores taken at multiple transects around the ship’s remains. Analysts noted a 12‑fold increase in plastic particle density compared to pre‑incident baseline levels documented in 2023. Microplastic concentrations reached 1,200 particles per kilogram of wet sediment, a figure that dwarfed the national average for comparable coastal zones..

The data also highlighted a significant proportion of these particles being nurdles, with sizes ranging from 0.1 to 3 millimetres, indicating a recent input from the wreck’s cargo holds. Concurrent to sediment sampling, SDMRI deployed remote‑operated vehicles equipped with high‑resolution cameras to inspect the wreckage structure. The imaging revealed extensive corrosion of the hull, exposing loose cargo pallets..

The pallets, previously secured in the forward hold, had been dislodged during the ship’s abrupt grounding, releasing thousands of nurdles into the surrounding waters. The imagery also captured several fish species, notably juvenile mullets, feeding in proximity to the cargo pallets, raising immediate concerns about microplastic ingestion. To understand the biological ramifications, the research team collected plankton samples from the water column up to 50 metres deep..

Results showed a dramatic uptick in the abundance of plastic‑laden zooplankton, especially copepods and euphausiids. These organisms, the primary food source for many pelagic fish, now carried detectable levels of nurdles in their digestive tracts. Early indications suggest a potential trophic transfer of microplastics, which could cascade through the marine food web and ultimately affect human consumers of local seafood..

In parallel, a community outreach program was launched to involve local fishermen and coastal residents. Interviews conducted across three fishing villages revealed increased fish mortality rates and a noticeable decline in catch quality. One seasoned fisher reported that several fish had been caught with visible plastic fragments in their stomachs..

While anecdotal, these observations corroborated laboratory findings and underscored the broader socio‑economic impact of the wreck. The long‑term assessment phase, slated for completion by late 2027, aims to monitor changes in sediment dynamics and microplastic persistence. SDMRI plans to install sediment traps and deploy autonomous surface vehicles to track particle dispersion patterns over seasonal cycles..

These tools will help determine whether nurdles are being entrained into deeper sediment layers or whether they remain buoyant, continuing to pose a risk to surface‑dwelling organisms. A critical component of the study involves assessing the effectiveness of current coastal cleanup protocols. Preliminary analyses suggest that standard beach‑cleaning operations are inadequate for addressing dispersed nurdles, which often settle in estuarine sediments rather than on the shoreline..

Consequently, TNPCB is exploring the feasibility of deploying specialized suction‑based equipment capable of extracting microplastics from shallow sediments without disrupting local benthic communities. Environmental NGOs have expressed concerns over the potential long‑term ecological damage. A recent report by the Green Coast Initiative highlighted that persistent microplastic pollution can alter sediment chemistry, affecting benthic invertebrate communities and compromising nutrient cycling..

The Keralam ELSA‑3 wreck, given its size and cargo composition, represents a substantial source of plastic input that could alter the ecological balance of the Gulf of Mannar, a region already vulnerable to climate‑driven sea‑level rise. The research team also examined the potential for chemical leaching from the wreck’s cargo. Laboratory tests on sediment samples revealed elevated levels of phthalates and bisphenol A, common plastic additives..

These compounds, known endocrine disruptors, could compound the physical hazards posed by nurdles, particularly affecting reproductive health in marine organisms. The dual threat of physical microplastics and chemical contaminants necessitates a comprehensive mitigation strategy. In response to the findings, TNPCB has announced the establishment of a dedicated task force to oversee remediation efforts..

The task force will coordinate with SDMRI, local authorities, and international experts to develop a phased removal plan. This plan will prioritize areas with the highest microplastic concentrations and will incorporate community‑based monitoring to ensure transparency and public participation. By early 2026, the first phase of targeted dredging and sediment bioremediation is expected to commence in the most heavily affected zones..

The project will employ bioaugmentation techniques, introducing specific bacterial strains capable of degrading polymer chains. While the efficacy of such approaches remains under investigation, initial pilot studies in similar contexts have shown promising reductions in microplastic concentrations over a six‑month period. As the long‑term assessment progresses, scientists anticipate that data will illuminate the natural attenuation processes governing microplastic fate in coastal environments..

The outcomes will inform policy decisions on shipping regulations, particularly regarding the transport of nurdles in bulk. If the study confirms persistent ecological damage, it could prompt stricter enforcement of maritime safety protocols and encourage the adoption of alternative packaging materials in the plastic manufacturing sector.