Growing up in East Pakistan (now Bangladesh), Purabi Chowdhury remembers a time when hilsa or ilish from the Padma and Meghna rivers was so abundant that no one really talked about it. “Back then, it was never a matter of discussion because it was easily available. It was also within everyone’s reach. There was neither any hype nor any scarcity,” says the 70-year-old.
During the monsoon, if there was no rohu or any other catch on the table, there was hilsa. It was simply another fish to cook and eat, not the prized seasonal delicacy it has become today, she adds.
Now settled in North 24 Parganas in West Bengal, Chowdhury returns to the fish market every season with the same questions: Kothakar ilish (Where is it from?) or taatka hobe toh (Is it going to be fresh?) The answer, she says, changes everything—from the texture of the flesh and the richness of its fat to the flavour that lingers long after the meal.
Few foods inspire the same emotional attachment among Bengalis as the hilsa. Meghnath Karan, 42, a third-generation fish seller at Manicktala wet market in north Kolkata, says those who love their ilish, will eat it only during season—starting in shrabon (monsoon) in July and extending up to Vishwakarma Puja (in September). Fish from cold storage, which is available year-round, will not do for them. Karan places a shiny, silvery hilsa on the ice and lifts the gills, to reveal the pinkish-red colour underneath, indicating it is fresh. The catch is from Raidighi, a wholesale hub for hilsa, in South 24 Parganas of the state. Fish from the cold storage, on the other hand, looks pale/yellowish and costs half the price. It also has a chewy texture and taste, he adds.
At the table, a meal typically begins with fried roe, eaten with hot rice stained yellow with lashings of the mustard oil it has been fried in. The heads may come next, cooked with eggplants, pumpkin or stir-fried with colocasia or Malabar spinach. And last, the curry, often cooked with brinjals and a frugal tempering of nigella seeds, or in a mustard gravy. A tidy line of bones around the edge of the plate is the sign of a good meal. Many debate about its source, and eventually which is better—Padma or Ganga ilish? The origin is as important as the fish itself.
Hilsa or Tenualosa ilisha is an anadromous fish. It spends most of its life in the sea and swims upstream during the monsoon to spawn. Although it is found at the mouth of other rivers and coastal waters across the subcontinent, Bengal’s hilsa is closely tied to its habitat—the Bay of Bengal. But increasingly, the provenance has become part of the conversation. It has also acquired new layers. As inland catches decline, a larger share of the fish now comes from the sea, say scientists, fuelling debates over origin, flavour and quality.
Experts point to juvenile fishing, erratic rainfall and overfishing as some of the major reasons behind its dwindling population in Bengal’s waterways. A ban on hilsa exports from Bangladesh has further complicated matters, forcing the state to look elsewhere to meet the growing demand. While Myanmar hilsa (from the Irrawaddy delta), commonly available in the local markets, has increasingly filled the gap over the years, a record catch off the west coast in Gujarat last year sent Kolkata fish markets into a frenzy. This raises a larger question: How does the community’s relationship with the fish change now that it is regularly brought in from an unfamiliar source? To mitigate the demand-supply gap every season, scientists in Bengal have also explored if it can be reared in freshwater ponds, an experiment that has met with some success. But can a farmed ilish carry the same emotional weight as one that arrives after its annual journey upstream?
IS IT FROM THE RIVER OR SEA?
In his office at the Central Inland Fisheries Research Institute (CIFRI) in Barrackpore, fisheries scientist Srikanta Samanta clicks on a slide tracking India’s hilsa production from 2001-16. The graph tells two stories. One, that India’s annual hilsa production had fallen from around 80,000 tonnes in 2001 to about 40,000 tonnes by 2016. The other is more worrying. The green line, representing riverine catches, falls away much more steeply than the red line denoting fish caught at sea and in estuaries. “Today, most of our ilish comes from the sea. Inland ilish has reduced significantly.”
For a fish whose cultural identity is inseparable from its annual journey upriver, the decline of riverine hilsa is more than an ecological statistic. It raises an unsettling question: what happens when Bengal’s most celebrated migratory fish can no longer complete the migration that has shaped its biology, flavour and place in the Bengali imagination?
Samanta has spent much of his career trying to understand—and arrest—the decline of India’s riverine hilsa. When he joined CIFRI in the early 1990s, researchers frequently travelled to the Farakka Barrage, where migrating hilsa, unable to negotiate the structure, often spawned below it. What happened next explained, in part, why the fish was disappearing. The river would teem with eggs, larvae and juvenile fish, only for them to be scooped up in fine-mesh nets before they had a chance to mature. “We caught them at whichever life stage we found them,” he says. “We never gave the fish a chance to breed even once.”
Farakka, he is quick to point out, was only one part of a larger story. Years of indiscriminate fishing, the capture of juveniles, shrinking spawning habitats and weak enforcement steadily depleted India’s riverine hilsa stock. Across the border, Bangladesh responded differently. It imposed seasonal fishing bans during the breeding months, declared hilsa sanctuaries, regulated the mesh size of fishing nets to prevent juvenile catch, and compensated fishing families for the income they lost while the ban was in force.
The results, Samanta says, are visible not just in the numbers but in the fish themselves. Bangladesh’s annual hilsa production has climbed from around 200,000 tonnes in the early 2000s to around 600,000 tonnes today, river catches have rebounded and the average fish now weighs over a kilogram. In India, by contrast, a 400-500g riverine hilsa has become a rarity. “Their stock is not depleted. They have been able to maintain it,” Samanta says.
The hilsa has always followed the monsoon. But weather experts say that the rhythm is beginning to change. According to the Intergovernmental Panel on Climate Change or IPCC’s Sixth Assessment Report (2021), changing monsoon patterns have resulted in more intense rainfall and greater fluctuations over time across South Asia. Furthermore, a 2015 study published in Weather and Climate Extremes in Science Direct suggests that climate change along with siltation and other human interventions is changing the environmental conditions the fish depend on to migrate and breed in the upper Bay of Bengal.
Rising water temperatures have also caused hatching rates to decline. “It is being observed that the sheer number of eggs that the fish are able to produce has reduced due to increased temperatures in the sea,” says marine conservationist and scientist Divya Karnad, who co-founded InSeason Fish, a sustainable seafood initiative in 2018. She explains that unpredictable rainfall, whether in the form of prolonged dry spells or short yet intense rain, dramatically changes the flow of the rivers, making it more difficult for the fish to swim upstream.
LOOKING WEST
The Gujarat hilsa makes a long journey. After growing up in the waters of the Arabian Sea, it swims towards the Gulf of Khambat and finally makes its way into the funnel-shaped estuary of the Narmada. When the monsoon arrives, the freshwater flow sends the mature fish upstream, towards Bharuch, to spawn. The fish is caught along this migratory route, close to where saline and freshwater meet.
Up until the 1980s-90s, it was a major catch between July and September, in the stretches of the Narmada, and a harbinger of good tidings for the fishing community. But things started to change when the Narmada Valley Project began the construction of the Sardar Sarovar Dam in 1987. According to a study published by the India Water Portal, an archival platform dedicated to water management, research and data, the construction of the dam reduced the monsoon flow of the river, thereby allowing more seawater to enter the estuary and increase its salinity. This considerably impacted the migration cycle of the hilsa from the sea to freshwater breeding grounds. The catch peaked in the early 1990s, but eventually declined over the following decades.
Bharuch has now become one of the key hilsa suppliers to Bengal. Local fish exporters note the region recorded excessive rainfall last year, which allowed more freshwater flow, and created the ideal environment for the fish to breed.
Gujarat hilsa flooding Kolkata markets is not a new phenomenon, says Nadeem Noor Mohammad Panja of Zenith Exports. The Veraval-based seafood export company has been supplying the fish to Kolkata for the past 15 years. Bengal, he points out, has imported it from the west coast for decades. But the fish became scarce as conditions changed in the lower stretches of the Narmada. Panja partly attributes this to industrial pollution/infrastructural projects around Bharuch, making it difficult for the fish to swim upstream to lay eggs.
Last August-September, following a record landing off the coast, Panja sent more than 200 tonnes of hilsa to Kolkata, varying from 700g to 1.2kg in size. Ask him if he is familiar with the craze and he says, “I know it is cooked in a dozen different ways. The one from Padma river is the best. But the locals here rarely eat it because of the excess bones. So we send off the entire lot to Kolkata.”
FISHY BUSINESS
The sentiment for Padma ilish runs deep, especially for those who had to migrate during Partition. When they left their homes, they also left the rivers behind that teemed with the silvery fish.
The longing endured. But in 2012, Bangladesh imposed a ban on exports to India to protect domestic supplies. In the years that followed, however, the Sheikh Hasina government made limited exceptions during Durga Puja, allowing small consignments to cross the border as a goodwill gesture. After her exit in 2024, the interim government initially ended this tradition, and then reversed the order with a one-time shipment of the fish during the festive season.
It comes at a time when Bengal’s own waters have little to offer. The usual catches from Digha, about 190km south-west of Kolkata, in the northern end of the Bay of Bengal, and Diamond Harbour on the eastern banks of the Hooghly, have been dismal, and above all is the khoka ilish or juvenile hilsa. “We are told to discourage the sale of small-sized hilsa by the state authorities, but how is it possible when there is no enforcement at the source where it is being caught?” asks Syed Anwar Maqsood, the secretary of the Fish Importers Association and Howrah Wholesale Fish Market Association.
Maqsood estimates more than 4,000 tonnes of hilsa to have arrived last August-September from Gujarat in Kolkata. He breaks down the economics, saying more fish means lower prices, and for a community that is forever hungry for hilsa, there will always be someone willing to take it home. He says last year the more abundant catch from the west coast sold for as little as ₹400- ₹600 a kg compared to the increasingly scarce yield from Bengal’s waters between ₹1500-1,800 a kg.
Fish seller Karan says the price depends on supply and the size of the fish. The bigger the fish, the pricier it is. When we met him a couple of weeks ago, fish weighing more than 2kg was priced at ₹4,000 a kg and smaller ones at ₹1,600 a kg. This is also the reason he sources fresh hilsa only in small quantities, around 10kg a day, so that he can sell what he buys. He has his dedicated customers, whom he informs immediately.
In September last year, around 100 tonnes of hilsa arrived from across the border ahead of Durga Puja, a consignment Maqsood describes as a disappointment. For the past six years, he has been working to revoke the export ban, and is considering writing to both governments once again, hoping to ease the restrictions.
The story around Padma’s ilish is also more to do with marketing than geography. Maqsood says not every fish touted as Padma’s ilish has been necessarily caught in the river. It could have been hauled in from the sea or another point along its migratory route. “Even the seller knows it is not from Bangladesh. The buyer knows it too. Yet, it is sold as Bangladesh ilish.”
TAMING THE HILSA
In 2012, Samanta and his colleagues embarked on what many considered an improbable scientific challenge: recreating enough of the ilish’s life cycle in captivity to secure its future.
The challenge was formidable. Hilsa is not rohu or catla—species that have been bred in captivity for decades. A migratory fish that spends much of its life traversing the sea, estuaries and rivers, the ilish had never adapted easily to ponds. Before scientists could even think of breeding it, they first had to answer a more fundamental question: could the fish survive—and grow—in captivity?
That question shaped the first phase of a multi-institutional ICAR project between 2012-17, led by ICAR-CIFRI, Barrackpore, with key contributions from ICAR-CIBA, Kakdwip, ICAR-CIFA, Rahara, and ICAR-CIFE, Kolkata. While CIFRI continued studying the hilsa in its natural habitat—its migration, spawning grounds and dwindling river population—its sister institutes specialising in aquaculture focused on a different problem: whether the fish could be reared in ponds. Earlier experiments had hinted that it was possible, but only briefly. This time, the researchers followed the fish over a much longer period. By the end of the project, they had crossed what Samanta calls the first major hurdle: they knew the ilish could survive and grow in captivity.
If the first phase established that it could survive in captivity, the second, between 2021-24, set itself a more ambitious goal: could it complete its life cycle there? The researchers began with wild brood fish caught during the spawning season. At the spawning grounds, eggs from female hilsa were fertilised with milt from males before being carefully packed in oxygenated bags and transported to research centres in Rahara, Kolaghat and Kakdwip. There, scientists attempted to raise them through every stage of life—from microscopic larvae and fry to fingerlings and, eventually, sexually mature adults.
That meant doing something no one had attempted successfully: recreating, inside ponds and laboratories, the conditions that nature ordinarily provides over hundreds of kilometres. The young fish were first sustained on naturally occurring plankton before being gradually weaned onto specially formulated feed.
Researchers experimented with different combinations of proteins, fatty acids and oils in an attempt to mimic the nutrition the fish would normally accumulate during its annual migration between the sea and the river. Different centres also tested how the fish responded to freshwater, brackish water and intermediate salinity.
The breakthroughs came one after another. The captive-reared fish not only survived but grew to adulthood. Males matured. Females, too, developed eggs. Using ultrasound scans instead of sacrificing the brood fish, scientists could monitor the development of their reproductive organs over time. “We now have the confidence,” Samanta says. “But the last step is the hardest.”
That final step has proved elusive. After inducing the captive-reared fish to breed, researchers watched fertilised eggs divide normally under the microscope—one cell becoming two, then four, then many more. Four hours later, the development stopped. The embryo never progressed further. Around the same time in 2024, the project’s funding cycle came to an end, although some of the work has continued through institutional support at partner institutes. “We now know it can be done,” Samanta says. “What we need is patience, and a sustained, long-term effort.”
Samanta is careful to distinguish the project from an attempt to turn the ilish into just another farmed fish. For him, the larger objective is twofold: conserving a species in decline while safeguarding the livelihoods of the fishing communities that depend on it. If captive breeding can eventually be perfected, he says, the fish need not remain in ponds at all. Juveniles could instead be released back into rivers—a practice known as ranching—to replenish depleted wild populations. But he is equally clear that captive breeding cannot, by itself, reverse the decline. Without stronger protection during the breeding season, better regulation of juvenile catch and greater awareness among fishing communities, he says, any scientific breakthrough will remain only part of the solution.
THE TASTE OF MEMORY
Saving the hilsa biologically is not necessarily the same as preserving everything it has come to represent. And that is exactly what food scholar and home chef Amrita Bhattacharya from Bolpur, West Bengal, is interested in understanding—how centuries of living with the fish has shaped local culture.
The memories, she says, are rooted in a time when ilish was not a luxury. Bhattacharya recalls hearing from an elderly resident of Chandannagar, Hooghly district, the stories his grandmother had passed down—of fishing boats camping along the river because the catches were so abundant that families had to preserve the surplus as nona ilish (fish preserved in salt) in the days before refrigeration. Similar memories survive elsewhere. In villages across Pabna in present-day Bangladesh, and even parts of Murshidabad, hilsa was once so plentiful that it could cost less than vegetables or lentils. Families ate it simply—steamed, boiled or lightly salted—letting the fish speak for itself.
Kolkata, she argues, has developed a different relationship with scarcity. Consumers assume that if they can pay enough, hilsa will somehow always be available. In smaller towns like Bolpur, where she lives, people remain more accustomed to accepting the rhythms of the catch. “If it hasn’t come, you wait,” she says. The expectation that every ingredient should be available throughout the year, she believes, has fundamentally altered the way we think about food—including the ilish.
That acceptance of seasonality, Bhattacharya believes, may once have been woven into Bengali food customs themselves. She wonders whether the tradition in many East Bengali households of giving up the fish after Bijoya Dashami and eating it again only around Saraswati Puja may have functioned, consciously or otherwise, as a way of allowing the fish to breed undisturbed. She points to similar practices elsewhere: Mumbai’s Koli fishing community traditionally stays away from the sea during the Shravan months (July-August) before venturing out again after Narali Purnima around late August. To Bhattacharya, such customs suggest that communities often evolved practices that aligned with nature’s rhythms long before we came up with the term “conservation”.
The science points in much the same direction. Samanta argues that the ilish’s celebrated flavour is itself a product of migration. During the marine phase of its life, the fish accumulates fat in its body. As the fish migrates upstream, that stored fat is gradually converted into fatty acids—a process Samanta believes contributes significantly to the distinctive flavour of Padma and Ganga hilsa. “Fat is the main thing responsible for the taste,” he says. “Sea hilsa will never have that flavour.”
Taste, however, is only one part of the ilish’s appeal. “Food is never just about the tongue,” Bhattacharya says. “Our likings begin in the brain.” Over generations, she argues, the fish has accumulated what she calls an “emotional semiotic”—a network of memories, rituals and associations that extend far beyond the dining table.
Those associations find expression in small domestic rituals. Bhattacharya points to the muro—the fish’s head—as an example. To someone unfamiliar with Bengali cuisine, the sight of a fish head, eyes intact, can be off-putting. Within many Bengali homes, however, deciding who gets the muro can signal affection, respect or intimacy, turning a meal into an unspoken expression of care.
The current shortage feels especially acute in Kolkata, she argues, because the city has turned it into a cultural marker. In many parts of Rarh Bengal, the arrival of the monsoon does not automatically trigger a rush for hilsa. Kolkata—and many East Bengali households—have invested the fish with a symbolism that extends well beyond appetite, shaping rituals of hospitality, reciprocity and celebration.
For those who have spent a lifetime eating the fish, the signs reveal themselves much before it reaches the plate. Sanhita D. Sensarma, 49, grew up on a steady diet of ilish in Agartala, Tripura, where proximity to Bangladesh meant access to hilsa from the Padma and Meghna rivers. It is perhaps why she refrains from eating the catch that comes from the west coast. “You cannot make Scotch or a Darjeeling first flush just anywhere. It’s the same logic.”
She explains the signs of a good hilsa lies primarily in its shape, texture and weight. “The shoulder or nape should be wide, and the layers of fat or marbling are the telltale signs of superior flavour. Once the fish is cut, the oil or grease left in between the fingers mean it will be tasty,” explains the Kolkata-based lawyer and food researcher with an interest in food systems. “Purists will also tell you not to wash the fish more than once arguing it washes away the natural oils, and with it, the flavour.” She points out that if the community is known for cooking its fish curries by frying the fish first, ilish makes for an exception. It is typically slipped straight into a curry with a coating of salt and turmeric, or steamed to retain its flavour.
ON RESTAURANT MENUS
While Kolkata’s food and drinks scene evolves with glitzy bars and cafes invading heritage buildings and old neighbourhoods, hilsa remains one tradition that Bengalis are not ready to part with just yet. Come August-September, hoardings announcing hilsa festivals appear above swanky flyovers, while restaurant menus fill up with recipes from another time and nose-to-tail preparations.
Oh! Calcutta, for instance, has been organising its annual “Ilish Utsab” for more than three decades across the chain’s outlets. To ensure a steady supply through the season, the team now blocks a portion of the catch by paying wholesalers in advance, an arrangement it introduced about six years ago. “The advance for this year, around ₹30-35 lakh, has allowed us to secure the best quality fish from mid-June through September, and maybe, until Durga Puja in October,” informs Anjan Chatterjee, the chairman and managing director of Speciality Restaurants.
The restaurant usually chooses hilsa from the Ganga (or Padma) depending on availability. Around 1,150kgs are procured every month during the season. But sourcing alone is not the deciding factor. Size is equally important, with the kitchen preferring fish weighing at least 1.2-1.5kg. Over time, it has served several recipes such as ilish-er fish fingers, kumro patay aam achar ilish, where the fish is coated with mango pickle and wrapped in pumpkin leaves, and this year, ilish korma. Chatterjee says Oh! Calcutta is among the first restaurants to introduce deboned hilsa, primarily catered for a younger generation of Bengalis, especially those living outside the state.
As concerns around dwindling fish stocks, food waste and sustainability become harder to ignore, some restaurants are taking a more considered approach. Instead of building elaborate seasonal spreads, they are planning limited menus, using the fish nose to tail and treating every catch with more care.
At Sienna restaurant in Kolkata, co-head chef Koyel Roy Nandy says the community needs to move beyond the nostalgia surrounding Bangladeshi hilsa. “As humans, we have a tendency to exaggerate and hype things. We must understand every ingredient has its own identity and value. There’s no doubt hilsa is expensive because it is delicious, but fish from Bangladesh is a product of different ecologies and biodiversity. Naturally, it will taste different. That doesn’t make one bad and the other good.”
Nandy recalls a trip to Chandpur in Bangladesh in 2017, where she had what she describes as her best hilsa experience, with thick, fatty cuts of belly portion. “I wouldn’t say Ganga ilish is bad. But, it does make for a more budget-friendly choice.”
What concerns her more is the way hilsa is consumed. “Many families buy smaller sized fish because everyone wants to cook it at least once during the monsoon, and it’s not financially possible to buy a large catch. It’s become a generational ritual. But that doesn’t mean we should eat whatever we get. We need to respect the fish and be mindful of how we consume it. I think that perspective is missing from the conversation.”
The larger issue, she says, is waste. “The amount of wastage in commercial kitchens, despite everything we know about sustainability, is sad. But this applies to any ingredient.” At Sienna, that philosophy shapes its annual hilsa menu during Durga Puja. Last year, it paid ₹2,800 for a kilo. “We do a limited menu for about 15 days and plan it carefully, and considering it is expensive, we use it nose to tail. The tail becomes a bhorta, the head goes into a tawk with fresh tamarind, and the steaks are gently confited in mustard oil. There’s a certain satisfaction in knowing we’ve used every part of the fish. And it’s not mandatory that we do it every season.”
Chowdhury has a measured approach. “If it’s just another day, I will make do with a small catch. But if I have guests over, I’d stretch myself and go for the best.” Perhaps it is time to look beyond the plate, and give hilsa a chance to complete its course, in keeping with the rhythms of nature and tradition.
Additional reporting by Nipa Charagi.