Walk into a mangrove forest in Goa, and you expect to hear the rustle of crabs, the call of birds, and the gentle splash of tidal water. But today, there is something else rustling beneath the canopy. It is the crackle of plastic wrappers. Fishing nets hang like ghosts on twisted roots. Bottle caps sit wedged between pneumatophores. The mangrove is whispering a warning, and it sounds alarmingly like plastic.
The mangroves of Goa, with their dark, tangled roots and hidden channels, rarely appear in the glossy brochures that promote the state’s beaches and nightlife. Yet these salt-tolerant forests are among the most precious ecosystems on India’s coast. They are the quiet sentinels that stabilise shorelines, nurture marine life, and store extraordinary amounts of carbon. As a new scientific study reveals, they are becoming sinks for the plastic that the modern world sheds at an astonishing pace.
What was once a natural filter for tidal flows is turning, inch by inch, into a graveyard for bottles, bags, and fragments of broken consumer products. The findings in this paper, ‘Anthropogenic litter pollution in the mangrove blue carbon ecosystem: Unveiling the spatial distribution, composition, source delineation and mitigation measures along the Goa coast, India’, paint a sobering, data-rich picture of how deeply human waste has infiltrated one of India’s most valuable blue-carbon ecosystems.
Mangroves: Goa’s natural guardians under pressure
Mangroves cover over 27 square kilometres of Goa’s coast. They stabilise shorelines, reduce flooding, support fish breeding, and store massive amounts of carbon. They also provide livelihoods to coastal communities. But mangroves are extremely good at trapping things that float into them. This includes plastic.
The researchers who undertook this investigation did not begin with the assumption that Goa’s mangroves were pristine. Tourism, urbanisation, and industrial expansion have transformed the coastal belt over the past two decades, stretching waste-management systems, increasing local consumption, and sending more discarded plastic into rivers, drains, and creeks. Yet even with this background, the sheer volume of anthropogenic litter they documented across seven mangrove sites startled them.
The study surveyed mangroves across Panaji, Chimbel, Chorao, Divar, Pomburpa, Agacaim and Querim. Sampling was done during low tide, covering more than 1,000 square metres of mangrove floor. What they found confirms what many locals have feared: mangrove ecosystems are becoming plastic traps.
What the study found: Plastic everywhere
Over the course of their fieldwork conducted during low tide, when the forest floor is most accessible, they counted a staggering 5,549 pieces of litter across just 1,080 square metres of sampled area. That works out to an average of roughly 5.14 items per square metre, with some sites, like Chimbel, recording more than double that density. The study’s statistical analysis confirmed that these differences were not random: some locations, especially those near dense settlements or heavily used creeks, have far worse litter burdens than others.
What stands out in the data is not just how much litter has accumulated but what it is made of. Plastic dominates with overwhelming consistency. In every site studied, plastic was the single largest category of litter, accounting for about 66 percent of all items collected. The most common types of plastic were the mundane but ubiquitous by-products of daily consumption—fragments of broken packaging, food wrappers, bags, sachets, styrofoam pieces, bottle caps, and discarded bottles. These small, lightweight items travel easily from households, tourist hotspots, and commercial areas into waterways, eventually settling in the quiet, root-dense zones of the mangroves.
In Querim, at the northern tip of Goa, plastic accounted for more than 80 percent of all debris; even the “cleanest” site, Pomburpa, still had more than 55 percent plastic in its overall litter composition. The pattern aligns with global research showing that mangroves, because of their structural complexity, act as natural traps for floating debris. Once plastic enters these forests, it is rarely dislodged.
Where is the plastic coming from?
An equally troubling dimension emerges when the study traces where this litter is coming from. By examining product labels, the types of items found, and the proximity of local activities, the researchers concluded that nearly 89 percent of the waste originated on land. This included household waste, food packaging, consumer plastics, and various forms of mismanaged solid waste. Sea-based activities—mostly fishing gear such as nets, ropes, and lines—made up the remaining 11 percent. Notably, none of the debris carried foreign branding or labelling, indicating that this was not litter swept in from distant currents but was almost entirely generated locally. The finding underscores how inadequate waste management, littering, stormwater runoff, and urban drainage systems funnel local pollutants into these fragile habitats.
Tourism’s shadow: When popularity becomes pressure
Tourism, widely celebrated as the engine of Goa’s economy, also leaves its mark in less visible ways. The Mandovi and Zuari estuaries, lined with mangroves, are hubs for cruising, boating, and other recreational activities. As tourist footfall has increased—over 10 million visitors in 2024 alone—so have the volumes of improperly discarded waste. Even when tourists do not litter directly, the waste generated by the businesses that serve them often finds its way into drainage canals and creeks. That refuse is eventually swept by tide and current into the mangrove interiors, where it becomes lodged among roots and sediment. The study’s data suggests that, without intervention, the rate of future accumulation will only increase.
Indices that tell a troubling story
To better understand the severity of the problem, the researchers employed a suite of environmental indices commonly used to assess coastal and urban pollution. Across all seven sites, the results were consistently alarming. According to the Clean Coast Index, every location studied fell into the category of “highly dirty”, with Chimbel scoring particularly poorly. The General Index, which looks at all forms of debris rather than just plastic, painted an equally grim picture. The Hazardous Items Index showed that several sites contained worrying amounts of dangerous litter—broken glass, sharp metal, sanitary waste, and other items that pose direct threats to both wildlife and humans. Finally, the Clean Environment Index, which incorporates weighting factors for different types of waste, rated every single site as “extremely dirty”. These findings are significant not only as environmental assessments but also as indicators of the risks faced by mangrove-dependent communities.
Why plastic in mangroves is dangerous?
While the numbers are striking, the ecological implications are even more concerning. The mangrove floor is a dynamic, breathing system. Its aerial roots, known as pneumatophores, are essential for gas exchange, especially in waterlogged soils with low oxygen. The study documented multiple instances of these roots being enveloped or constricted by plastic debris. When pneumatophores are covered or smothered, they cannot perform gas exchange effectively, creating localised anoxic conditions that weaken or kill portions of the plant.
Plastics caught among branches and stems block sunlight, disrupt photosynthesis, and stunt growth. Over time, sustained suffocation can accelerate root growth in unnatural ways, cause deformation, or trigger leaf loss. These impacts, though subtle at first, have cascading consequences for the health of the entire mangrove stand.
From macroplastics to microplastics: The threat we don’t see
As plastic breaks down into smaller particles, the ecological risks multiply. The transformation of macroplastics into microplastics and nanoplastics—driven by sun exposure, wave action, and microbial degradation—means that the pollution does not remain confined to the forest floor. Tiny particles infiltrate sediments, adhere to biofilms, and are ingested by organisms ranging from crabs and molluscs to commercially important fish species.
Several global studies have shown that microplastics can travel up the food chain, carrying toxic chemical additives and absorbed pollutants. More than half of plastics contain compounds classified as hazardous under the UN’s global classification system, raising the possibility that local human populations could be exposed to these contaminants through seafood consumption. Evidence from other mangrove systems, such as the Sundarbans, shows clear trophic transmission of microplastics all the way to tertiary consumers, underscoring the seriousness of this threat.
Plastic and the future of Goa’s coastal communities
Litter accumulation also jeopardises the next generation of mangroves. Seedlings and propagules, which rely on unobstructed space to settle and take root, are easily crushed, entangled, or displaced by plastic debris. Earlier studies referenced in the paper show that debris-covered areas experience higher seedling mortality and more physical damage to branches and bark. For mangrove forests already under pressure from land-use change, rising sea levels, and climate-related stressors, such impediments could reduce resilience and regeneration rates.
When mangroves decline, so do the ecosystem services they provide: coastal protection weakens, fish nurseries shrink, carbon sequestration declines, and water filtration capacity drops. The economic consequences can be severe, especially for coastal communities that depend on fisheries, aquaculture, and ecotourism.
The bigger picture: A national and global plastic emergency
The researchers emphasise that Goa’s waste problem is not an isolated phenomenon but part of a much larger trend sweeping across the Indian Ocean region. India is among the top global producers of mismanaged plastic waste, and with rapid urbanisation and consumption growth, the volume entering natural systems continues to rise. Studies predict that plastic emissions in coastal habitats may increase by more than 50 percent by 2030 if present trends continue. Waste-management infrastructure has not kept pace with this surge. Nearly 40 percent of India’s plastic waste ends up in landfills, and a significant fraction escapes into the environment due to imperfect segregation, collection, and recycling systems. Even strong policy measures—such as India’s ban on many single-use plastics and the introduction of extended producer responsibility rules—struggle to translate into on-ground change without strict enforcement and sustained public engagement.
Can this trend be reversed? Possible paths forward
Goa has attempted a range of interventions. The state government banned single-use plastics in 2019, intensified clean-up drives, and expanded awareness programmes through nationwide campaigns such as Swachh Bharat Abhiyan. But these efforts have not been enough to counter the sheer volume of waste produced by tourism, urban settlements, and local commerce. Waste segregation remains inconsistent, recycling facilities are insufficient, and enforcement of bans is often patchy. The study suggests that without robust, region-specific mitigation strategies, plastic pollution will continue to undermine the ecological stability of the state’s mangrove ecosystems.
Strengthening waste management systems—especially in urban and tourist areas—is essential. Infrastructure for collection, segregation, and recycling must be scaled up significantly. Community-level interventions, including incentives for responsible waste disposal, buy-back schemes for fishing gear, and public education campaigns, can reduce the flow of debris into waterways. Ultimately, source control is far more effective than relying solely on periodic clean-up efforts, which offer only temporary relief.
A warning and an opportunity to protect Goa’s coastal guardians
The study’s conclusions are unequivocal: Goa’s mangroves are heavily polluted, ecologically vulnerable, and in urgent need of targeted intervention. With plastic accounting for two-thirds of all litter, and most of it originating on land, the responsibility for action falls squarely on human systems—municipal bodies, industries, tourism operators, and residents alike. Mangroves are among the most resilient ecosystems on Earth, capable of withstanding storms, tides, and fluctuating salinity. Their undoing, however, may come from something far quieter: the creeping accumulation of human waste that chokes their roots, poisons their soils, and infiltrates their food webs. If left unaddressed, the degradation of these forests will ripple through coastal economies, cultures, and livelihoods.
Yet the researchers also make clear that this crisis is not irreversible. With strong policy reforms, effective waste-management systems, community participation, and sustained public pressure, the trajectory can still change. The mangroves have long protected the people of Goa. It is now up to the people to protect them before these coastal guardians are overwhelmed by the tide of plastic at their feet.