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In Pulinkunnu, a village in Kerala’s Alappuzha district’s Kuttanad region, the waters that once supported livelihoods are now strangled by a green invader. Water hyacinth, a fast-spreading aquatic weed, has blanketed canals and backwaters, obstructing fishing, choking irrigation channels, and posing serious health risks to local communities.
Though water hyacinth (Eichhornia crassipes) is known globally as an aggressive weed, its impacts in India remain poorly documented at the local level. A recent study by Aji Abba and Sabarinath S titled ‘Sustainable management of water hyacinth (Eichhornia crassipes): Community-led strategies for livelihood enhancement in rural India,’ published in Results in Engineering, sheds light on the Kuttanad region’s ongoing battle—and how the community is seeking solutions from the ground up.
Water hyacinth (Eichhornia crassipes) often appears as a green layer of dense vegetation on rivers, ponds, and lakes. A fast-growing aquatic plant, it normally provides shelter and feeding grounds for a range of aquatic animals. However, under conditions where water bodies are polluted with a high nutrient load, these free-floating and highly invasive aquatic plants can proliferate rapidly, forming a dense green layer on water bodies and posing a risk to the natural habitats of the freshwater ecosystems. In Kuttanad, these mats now cover 75–94 percent of surface waters, with hotspots near farmlands, residential areas, and canals.
Water hyacinth thrives in nutrient-rich waters, especially those loaded with agricultural runoff or untreated sewage. Its rapid growth forms dense mats that block sunlight, deplete oxygen, and disrupt aquatic ecosystems. As the weed grows, it alters water chemistry. The study found high nutrient loads, increased acidity, and elevated levels of total dissolved solids (TDS) in infested waters.
Rampant growth of this weed can also slow down water currents, leading to stagnation and creating conducive conditions for mosquito breeding and the spread of diseases such as malaria, encephalitis, filariasis, etc. Contamination by E. coli bacteria and visible turbidity point to deteriorating water quality—posing health risks to people and animals alike.
Dense growth of the weed in water can cause massive water losses through transpiration, which can be three times higher than natural evaporation. Infestation with water hyacinth can also negatively affect irrigation facilities by decreasing water flows and also interfere with recreational activities such as swimming, fishing, and boating. During floods, heavy floating mats of the weed can dislodge and cause significant damage to downstream infrastructures such as bridges and fences and to crops and pastures.
It is no surprise that this invasive weed has spread to more than 141 countries and 24 Indian states with its remarkable ability to multiply. For example, 10 water hyacinth plants can reproduce into 655,360 plants, covering approximately half a hectare in 8 months. In India, control measures cost over ₹2.3 billion annually, with approximately two million hectares of water bodies affected by this invasive species.
Kuttanad, a Ramsar-designated wetland in Kerala, is particularly vulnerable to water hyacinth invasions due to its below-sea-level farming systems and complex hydrology. The region has an intricate network of backwaters and canals, and the Pampa River serves as a main source of water in the region. People in the region practice intensive rice and coconut farming.
This study conducted in the Kuttanad region involved the community in mapping the spread of the weed and evaluated its impacts on water quality, health, agriculture, and fisheries in the region. The study also explored sustainable ways of managing the growing menace of water hyacinth.
The community was involved in mapping the spread of water hyacinth in Kuttanad, and it was found that the weed covered 75 to 94 percent of the surface area of water bodies in the region.
The growth hotspots were concentrated in areas close to agricultural lands, canals, and densely populated residential areas, indicating that water enriched with nutrients from agricultural runoff such as nitrogen and phosphates and human and animal waste led to overgrowth of water hyacinth. The water quality of the area showed that the water was highly acidic, high in iron due to industrial effluents or natural minerals, and high in dissolved ions leading to high TDS possibly due to agricultural runoff or sewage intrusion.
The water covered with dense layers of water hyacinth was found to be highly turbid and contaminated with E. coli bacteria, indicating that the thick vegetation mats contributed to oxygen depletion and created anaerobic environments conducive for bacterial proliferation.
The thick mats made it very difficult for fishermen to manoeuvre in the waters and affected their fishing activities. It also led to a reduction in fish count due to fish deaths because of loss of oxygen from the waters.
Water hyacinth growth also disrupted agricultural irrigation due to blockage in the flows of the water. Similarly, fishing was severely affected due to blocked waterways, oxygen depletion, and fish habitat loss. Small businesses also suffered, with 83 percent of people reporting negative consequences, possibly due to reduced water transport efficiency and increased maintenance costs.
Economic losses from fishing, boat damage, and health-related expenses reached upto Rs. 3000 per month per household, primarily due to reduced fish catch and increased costs associated with clearing waterways. This loss accounted for approximately 20 percent of the average monthly household income in the region—a significant amount that exacerbated financial instability for affected communities. Observations and information from the local population also revealed that there was a significant decline in native fish species, with 76 percent of surveyed fishermen reporting reductions in fish catch.
A number of people experienced waterborne diseases, skin irritation, and fungal infections of legs, which they associated with frequent contact with contaminated or stagnant water hyacinth-infested waters.
The study found that the community was keen to find sustainable solutions to the problem of water hyacinth and showed interest in utilising water hyacinth as a biofertiliser due to rising costs of chemical fertilisers. This community demand for sustainable solutions is now driving a collaborative effort in Kuttanad to develop biofertiliser as an alternative to chemical fertilisers, supporting sustainable agricultural practices.
They can help in leveraging locally available biomass to produce a cost-effective, nutrient-rich organic fertiliser that improves soil fertility and crop yields and reduces dependence on synthetic fertilisers.
Their low installation cost and simple production process make them accessible to small and marginal farmers.
Its use in saline soils has shown promising results in mitigating salinity stress for crops such as tomatoes and potatoes.
Use of water hyacinth for making biofertilisers is as beneficial as microbial populations within water hyacinth support plant growth through phytohormone production.
In addition to promoting biofertilisers, the study recommends a broader set of strategies to manage the water hyacinth crisis. These include reducing nutrient inflows from agricultural runoff and untreated wastewater—major contributors to the weed’s rapid growth—through stronger policy interventions and improved water quality regulations.
It also highlights the potential of investing in sustainable aquaculture to diversify local livelihoods and reduce dependence on fisheries affected by the infestation.
Furthermore, introducing structured cash-for-work programs, which have shown positive results in wetland restoration projects in Southeast Asia and East Africa, could provide both ecological and economic benefits in Kuttanad.