Assam's Son Beel Wetland: A Seasonal System of Inundation and Retreat

Debarun Choudhury Each year, as winter begins around mid November, Arup Das looks out across the marsh surrounding his home in Dargarbond, one of the many villages around Son Beel, a seasonal wetland in Assam. The land around him was submerged under water just a couple of months ago. Now, as the water recedes, he releases his ducks to forage for snails, aquatic plants, insects, and whatever else the retreating waters leave behind. Son Beel is the largest wetland in Assam with a fluctuating size since it expands during the monsoon and contracts during the dry season. More than 50,000 people depend directly on this wetland for their livelihoods. “A wetland is not simply a body of water,” says Tapati Das, an ecologist heading the Department of Ecology and Environmental Science at Assam University. “It is a system of inundation and retreat, of channels and marshes, which naturally replenishes a landscape in cycles.” Tapati describes Son Beel as a freshwater wetland with pronounced seasonal changes in water coverage. “During the monsoon, water spreads across the surrounding lowlands. Flooding expands aquatic habitat; recession concentrates organisms in remaining pools and exposes substrates for terrestrial plants and cultivation,” she elaborates. The seasonal shift is not a temporary interruption to Son Beel’s ecology. “It is part of how the wetland functions.” This cycle shapes fish habitats and determines when land will become available for crop cultivation, and also creates feeding grounds for Arup’s ducks. Back on his farm, ducks of Nageshwari breed are part of an integrated farming system. Their droppings are used as fish feed in his ponds and fishery. However, the impacts of climate change, including erratic rainfall or disasters, and non-climatic factors such as overexploitation of fish, soil erosion, siltation, pollution, shrinking wetland area and declining wetland depth, pose challenges for people who depend on the wetland for livelihood. Some farmers and fishers are adapting to the changes in the beel by diversifying their income sources. Coming from a farming family, Arup began his journey towards integrated farming in 2014 with a single cow. By 2025, his herd had grown to twenty. But in a village where almost every family keeps cattle, the growth of his herd did not translate into a steady source of income. The cost of cattle maintenance outweighed the need for milk in the local market. He has since sold sixteen cows over the years, and now only four remain. A section of his farm is now home to 300 female golden breed chickens (locally known as Sonali) that produce about 250 eggs per day. Another section houses an incubator that hatches ducklings for the next generation, while he cultivates the remaining 0.4 hectares of land for winter crops such as boro rice, pulses, brinjal, and rajma. He started rearing Nageshwari ducks in 2018, after veterinarians from Khanapara Veterinary College introduced him to the breed. With assistance and input from the Krishi Vigyan Kendra (KVK), he developed a registered business in 2020. The farm now has about 1,200 ducks, and its weekly hatching operation produces around 1,000 ducklings. He says, “The incubator must maintain a temperature of 37°Celsius, a requirement that becomes harder to manage when temperatures fluctuate beneath the farm’s tin roof.” Around 10 to 12 families in Dargarbond, and two other villages — Anandapur, and Kalyanpur — have adopted integrated farming. But this diversification plan is not equally accessible to everyone. A study published in December 2025 examined the risks facing farming communities around Son Beel. Researchers interviewed 160 households across 16 villages and assessed their exposure to environmental hazards, their dependence on natural resources and their capacity to adapt. Anandapur gram panchayat (which includes Dargarbond), where Arup lives, is better positioned to deal with climate-related problems than people in some other villages like Krishna Nagar and Bhairab Nagar, where livelihood diversification is limited. The study found that these villages exhibit higher socio-ecological vulnerability, indicating a heightened climate risk. Farmers in these villages have faced severe flooding, hailstorms, declining income from crop cultivation, and wetland degradation. They require “enhancing livelihood diversification, education, and housing infrastructure,” to be resilient from future climate impacts, the study notes. Pulakabha Chowdhury, a senior scientist and the head of Krishi Vigyan Kendra (KVK) in Sribhumi district (which contains Son Beel and the surrounding villages), estimates that only about 5% of farmers have adopted livelihood diversification. He says, “A farmer who owns little land may have nowhere to construct a fishpond. Another may understand the benefits of integrated farming but lack the money to invest in livestock, poultry or an incubator. Even where the land and capital are available, managing several enterprises requires labour and time.” Awareness is another obstacle. According to Chowdhury, “Only 10 to 15% of farmers are aware about alternative crops and livelihood opportunities.” He adds, “Many prefer crops such as seedless tomatoes because they offer the prospect of quicker returns. For households with little financial room to absorb a prolonged harvest, a crop offering quicker returns is the less risky choice.” Samim Borbhuyan, a research scholar in the Department of Ecology and Environmental Science at Assam University says, “The soil around Son Beel is suitable for dragon fruit and foxnuts, also known as makhana. But cultivating unfamiliar crops can require new skills, upfront investment and a wait for returns, with no guarantee that buyers will be available.” Chowdhury says the cost for adopting integrated farming differs on a case-by-case basis. “Arup’s integrated farming model combines several activities, but adopting it requires more than suitable land. Farmers must also be able to finance livestock, ponds, equipment and the labour needed to manage them. For households with limited land or capital, it is very difficult,” he explains. This is why a farming system that works for Arup remains out of reach for many households scattered across the villages around Son Beel. While farmers like Arup view integrated farming as a response to climate variability, they say it’s difficult to gauge the effects of climate change on integrated farming at this point as it is new and emerging. “But the summers are getting both intense and longer in Assam,” Arup says. During the monsoon, as the water swells, hundreds of families who do not depend primarily on traditional fishing turn to a practice known locally as mahajaal or net fishing. The practice involves enclosing sections of rising water with nets, creating spaces where fish can be trapped and harvested. For fisherman Maheshwar Das, the operation begins in a small pond. “I begin with a small batch of fish raised in my pond before transferring them to a 20-bigha net fishery I set up,” he says. “It is a bit costly as it requires nets, bamboo and labour, each adding to the cost.” Maheshwar proceeds to sell his catch to arats , which are local wholesale trading depots through which fish enter the wider market. The availability of fish, however, does not guarantee a profit. Maheshwar says, “During spring and the monsoon, fish sometimes contract diseases and die,” adding, “I could not recover the costs last year as there was disease that was going around; other people I know also faced severe losses.” To supplement his income, Maheshwar buys young ducks, raises them for up to four months and then sells them, rather than maintaining a year-round duck-rearing and hatching operation like Arup. According to Anupam Sharma, the District Fishery Development Officer (DFDO) of Sribhumi, around 400 hectares of Son Beel are productive for fisheries. “The wetland once had 24 group fisheries, of which 14 have since become non-productive due to siltation,” he says. A 2019 review suggests that sediment entering Son Beel from Singla river is faster than it leaving via Kachua river, which carries water from the northern end of the beel towards the Kushiyara river. Sharma cites fishery department records and says the annual fish production of 824,000 kg in 2020-21 from Son Beel. The records list 61 fish species across seven orders and 41 genera, belonging to 24 families, he says. Among the most commonly available fish, Sharma identified Trichogaster fasciata , followed by Amblypharyngodon mola ( mola ) and Esomus danricus ( darkina ). A 2023 study which surveyed fish in the rivers and wetlands of Sribhumi district, recorded 45 species across the water bodies it examined. The study noted fishermen’s reports of a considerable decline in fish production over the preceding decade, associating it with deteriorating water quality and agricultural chemicals entering rivers and wetlands. Raman Das, a traditional fisher from the district, describes a decline in variety. He says “ Chapila ( Gudusia chapra ), basa ( Eutropiichthys vacha ) and pabda ( Ompok pabda ) are varieties that are no longer readily available as they once were.” Raman attributes the decline to motorboats used by tourists and net fishing. Tapati cites a 2017 survey that documents diverse fishing practices and the use of unsuitable fishing gear. The study notes that small mesh nets can severely damage wetland ecosystems by indiscriminately capturing juvenile fish, while gear spanning channels can obstruct movement and, in turn, affect fish populations. According to Borbhuyan, “Increased tourism is also contributing to plastic pollution, which affects the wetland’s ecology.” While peak monsoonal floods still inundate the seasonal floodplain, a 2025 study found that the wetland’s deep-water core is disappearing. Researchers analysed satellite imagery gathered over a decade, revealing that perennial water bodies had nearly halved, from 0.66 square kilometres in 2015 to 0.33 square kilometres in 2024. These pools serve as the permanent refuges essential for fish survival during the dry winter months. As silt clogs the basin during dry season and water tables drop, exposed lake beds are colonised by invasive water hyacinth ( Eichhornia crassipes ) or are converted into winter Boro rice paddies by farmers. This internal collapse mirrors macro-level changes across the wider watershed between 1990 and 2020. A separate watershed study published earlier this year, revealed that the mapped water-body area fell from 46.44 to 39.64 square kilometres across the catchment, while swamp and marshland, the natural hydrological sponges, steadily contracted. It also notes that surface runoff and sediment delivery have also accelerated in the Singla river basin due to upland disturbances and high silt build-up. The Singla river drains the surrounding catchment, including parts of the Mizo Hills, before entering Son Beel as its main inlet, carrying water and sediment from upstream into the wetland. The state government’s plans for Son Beel include improvements in tourism infrastructure and a proposed floating solar project . However, a statewide project to restore wetlands and expand fisheries, called “Sustainable Wetland and Integrated Fisheries Transformation” ( SWIFT ), has been launched, which does not include Son Beel. SWIFT is backed by the Asian Development Bank and implemented through the ARIAS Society and the state fisheries department. In a written response to questions about the project, Himangshu Talukdar, the District Project Director of ADB-SWIFT, confirmed that no package or project component had been approved for Son Beel. The government targets higher tourism, fish production, infrastructure and new livelihoods. But economic incentives alone cannot outweigh ecological health, experts warn. Tapati shares, “Before intervening in Son Beel, we need a clear picture of how it changes through the seasons. That means measuring water levels, the duration of flooding, water flow through channels, sediment deposits and water quality.” She adds, “We also need to document native and invasive plants, fish, other aquatic life, and waterbirds, as well as fishing, farming, aquaculture, and, most importantly, the livelihoods that depend on the beel.” She recommends comparing a full year of data with historical records, as the region experiences increasing monsoon variability. Meanwhile the families around Son Beel are building livelihoods and adapting to these changing ecological conditions. This article is republished from Mongabay under a Creative Commons license. Read the original article here .