Industrial vessels, operating 24/7 with fine-mesh nets, harvest juveniles before they can reproduce, creating a vicious cycle of recruitment failure. Data shows that 70 per cent of caught fish are below maturity size.

In a stark revelation that underscores the fragility of Bangladesh’s marine lifeline, fish stocks in the Bay of Bengal have plummeted by nearly 80 per cent over the past seven years, threatening the livelihoods of millions and the nation’s food security. Preliminary findings from an ongoing international survey, released today, paint a dire picture of overexploited waters where once-abundant catches now dwindle to shadows of their former bounty. From 158,100 tonnes in 2018 to a mere 33,811 tonnes in 2025, the decline – pegged at 78.6 per cent – signals a crisis born of unchecked industrial fishing and environmental strain.

This catastrophic drop has reshaped the underwater ecosystem, reducing the number of commercially viable major fish species from nine to just five. Iconic catches like tiger shrimp, Indian salmon, and large croakers – once staples of Bangladeshi markets – have been severely depleted, forcing fishermen into riskier, less profitable ventures. “The Bay is emptying faster than we can replenish it,” said Abdullah Al-Mamun, assistant director of the Department of Fisheries. “Overfishing isn’t just a buzzword; it’s the executioner of our marine heritage.”

The survey’s data, gathered aboard the state-of-the-art research vessel Dr. Fridtjof Nansen, highlights how the proliferation of industrial trawlers has accelerated the depletion. In 1985, only 100 such vessels prowled the waters; today, that number has ballooned to 273, many operating with outdated or harmful gear. Of these, 72 trawlers lack proper technology, leading to excessive bycatch – unintended captures of juvenile fish and non-target species – and massive wastage that further erodes stocks. Fishermen in coastal districts like Cox’s Bazar and Chattogram report hauling nets that return half-empty, with average daily yields slashed by over 60 per cent since the early 2010s.

Beyond the numbers, the human toll is profound. Bangladesh’s fisheries sector, which employs over 11 million people and contributes roughly 3.5 per cent to the GDP, faces existential threats. Small-scale artisanal fishers, who depend on the Bay for 80 per cent of their income, are hit hardest. In villages along the 710-kilometer coastline, stories abound of families skipping meals or migrating inland for low-wage labour.

Amina Begum, a 45-year-old fisherwoman from Kuakata, shared her plight: “We used to catch enough hilsa in one dawn to feed our children for a week. Now, it’s a struggle for a single meal. Our children are leaving the sea for the cities, and our traditions are dying with them.”

Environmental degradation compounds the overfishing scourge. Low oxygen levels in oxygen minimum zones, coupled with surging microplastic concentrations and abnormal jellyfish blooms, are suffocating marine life. Fisheries and Livestock Adviser Farida Akhter warned that these are “red flags of a collapsing ecosystem,” exacerbated by illegal, unreported, and unregulated (IUU) fishing and the rampant use of destructive nets that scoop up everything in their path. “Harmful practices like bottom trawling are not just depleting stocks; they’re destroying habitats that future generations won’t inherit,” Akhter emphasised.

As the survey’s full report looms – expected in mid-December – stakeholders are mobilising. The government has pledged stakeholder consultations to curb trawler licenses and enforce stricter regulations, but experts caution that half-measures won’t suffice.

A Beacon of Hope in Fisheries Assessment

Launched in August 2025 under the auspices of the EAF-Nansen Programme – a 50-year-old collaboration between the Food and Agriculture Organization (FAO) of the United Nations and Norway – the 32-day expedition marked a pivotal step in understanding the Bay’s plight. Aboard the Dr. Fridtjof Nansen, a 78-meter vessel equipped with cutting-edge acoustic and biological sampling tools, a multinational team of 13 Bangladeshi scientists, regional experts, and a 26-person crew traversed key transects from Chattogram to the Andaman Sea.

The mission’s scope was ambitious, targeting not only fish abundance but the broader health of the marine environment. Researchers quantified populations of mesopelagic and small pelagic species – vital to the food web – as well as demersal fish like croakers and pomfrets. Environmental metrics painted a multifaceted portrait: sea temperatures rising 0.8°C since 2015, salinity fluctuations linked to erratic monsoons, and pH levels dipping toward acidification thresholds. Primary productivity data revealed patchy phytoplankton blooms, while ocean current mappings exposed how warming waters are shifting migration patterns, pushing valuable species like hilsa farther offshore.

Microplastic sampling yielded sobering insights, with concentrations averaging 1.2 particles per cubic meter in surface waters – double the 2020 baseline. Marine litter, including discarded nets and industrial debris, entangled sampling gear on multiple occasions, underscoring the pollution crisis. “This survey isn’t just about counting fish; it’s about diagnosing the ocean’s fever,” said Dr. Saleha Sultana, lead Bangladeshi marine biologist on the voyage. Her team processed over 500 water and plankton samples, using onboard labs to analyse CO2 absorption rates that could inform climate adaptation models.

The expedition’s real-time data feeds have already influenced preliminary advisories. For instance, early acoustic surveys detected a 45 per cent drop in mid-water fish biomass near the continental shelf, prompting temporary no-trawl zones proposed for high-vulnerability areas. By integrating satellite telemetry with vessel-based hydrography, the team mapped oxygen-depleted “dead zones” spanning 15,000 square kilometres – expanding 20 per cent since the last regional assessment in 2018.

Crisis Drivers: Overfishing and Ecosystem Strain

At the heart of the fish stock collapse lies overfishing, a relentless pressure amplified by Bangladesh’s booming seafood export industry, valued at $500 million annually. The influx of mechanized trawlers, many imported from neighbouring countries, has turned the Bay into a competitive battleground. Industrial vessels, operating 24/7 with fine-mesh nets, harvest juveniles before they can reproduce, creating a vicious cycle of recruitment failure. Data shows that 70 per cent of caught fish are below maturity size, per department of fisheries logs.

IUU fishing adds insult to injury, with foreign fleets encroaching on Bangladesh’s exclusive economic zone (EEZ) – a 118,813 square kilometre expanse teeming with potential but policed by just 12 patrol boats. Satellite imagery from the survey corroborated reports of 50+ unauthorized incursions monthly, siphoning an estimated 20,000 tonnes of undeclared catch yearly. “We’re losing a war we can’t afford,” lamented environmental activist Rezaul Karim, whose NGO monitors coastal encroachments. “Without bilateral enforcement pacts, our waters remain an open buffet.”

Climate change weaves through these threats like an invisible net. Warmer surface waters have stratified the ocean, trapping nutrients below the photic zone and starving surface ecosystems. Jellyfish proliferations, up 300 per cent in sampled areas, outcompete fish for plankton, while coral bleaching in shallower reefs disrupts spawning grounds. The survey’s carbon data links these shifts to global emissions, with Bangladesh – despite low per-capita output – bearing disproportionate brunt as a low-lying delta nation.

Socioeconomic inequities exacerbate vulnerabilities. Artisanal fishers, lacking access to cold chains or market intel, sell at rock-bottom prices to middlemen, fuelling a debt trap that discourages sustainable practices. Women, who process 60 per cent of landings, face amplified hardships from reduced volumes, with household nutrition scores dropping 15 per cent in fisher communities per recent FAO metrics.

Policy Imperatives for Sustainable Marine Harvest

As the Nansen docked in mid-September, handing over terabytes of raw data to Dhaka’s fisheries labs, optimism flickered amid the gloom. The survey’s outputs align with the UN Decade of Ocean Science (2021-2030) and FAO’s Blue Transformation Roadmap, aiming to triple ocean productivity by 2030 through science-driven governance.

Key recommendations urge halving the trawler fleet within five years, via buyback schemes funded by Norway’s $10 million pledge. Enforcing minimum mesh sizes – currently flouted in 40 per cent of operations – could boost juvenile survival by 30 per cent, modelling from IMR simulations suggests. Community-led monitoring, empowered by app-based reporting tools piloted in the survey, promises grassroots enforcement.

Investing in aquaculture offers a buffer: Bangladesh’s marine fish production climbed from 4.9 million tonnes in 2022-23 to over 5.0 million last year, but wild capture still dominates. Hybrid models, blending offshore pens with stock enhancement, could restore 20 per cent of lost yields by 2030, per economic forecasts.

International solidarity is crucial. The EAF-Nansen framework fosters knowledge transfer, training 50 Bangladeshi researchers in advanced sonar and genomic tagging. “This isn’t charity; it’s shared survival,” noted FAO’s regional director, Lars Eric Pedersen. “The Bay’s health ripples across the Indian Ocean.”

In the end, the Bay of Bengal’s story is one of hubris and hope – a call to steward the seas before they slip away. As Farida Akhter implored, “We fished for tomorrow once. Now, we must farm it.”