- The number of fishing boats operating in the northern Bay of Bengal is in excess of the sustainable limit, resulting in overexploitation of the hilsa population.
- There has been a persistent decline of fish catch in spite of increasing efforts, a recent study reports. Between 2002 and 2015, even though the number of boats engaged in fishing increased by 25 percent, the hilsa catch dipped by 13 percent.
- The study draws attention to the haul of juvenile hilsa and first spawners due to small mesh-size nets, which are detrimental to fish stock.
- The enforcement of regulations is important for India to meet the Sustainable Development Goal 14 as a signatory. SDG 14 commits countries to protect oceans and the lives that depend on it.
Tajen Das’s voice is full of foreboding. It mirrors the choppy waters of the Bay of Bengal as he spruces up his fishing boat and gear for the upcoming hilsa (Tenualosa ilisha) season in the monsoons.
“My men are ready. My boat is ready. The fishing nets are in place. We are waiting for June when the monsoons begin. But how long will the hilsa survive in Bengal? The reign of the ‘king of fish’ may soon be over,” continued Tajen Das, a fisherman associated with a south West Bengal’s fishermen forum.
The highly sought-after, silvery trans-boundary fish that travels between the saline seawater and the sweet river water, is not only integral to the socio-economy of West Bengal in east coast of India and neighbouring Bangladesh but also to diplomatic parleys.
A hilsa fish can weigh up to 2.5 kg and is rich in Omega-3-fatty acids. Inspiring poets and artistes, the “darling of waters“, is imperiled by over-exploitation in northern Bay of Bengal. What has dismayed Tajen and his co-workers is a persistent decline in hilsa catch in West Bengal waters despite revamped efforts.
“It is extremely unnerving to watch the catch dwindle even as we press more boats into service,” said Tajen Das.
Unsustainable fishing pressures
In a new study, scientists questioning the sustainability of hilsa fishing practices in the northern Bay of Bengal region suggest that an excess of licensed fishing boats (mechanised boats or trawlers and non-motorised boats) are to blame for the plummeting stock.
The study states that between 2002 and 2015, even though the number of boats engaged in fishing increased by 25 percent, the hilsa catch dipped by 13 percent.
“At present, the number of boats operating in the northern Bay of Bengal has gone beyond the sustainable limit resulting in over-exploitation of the hilsa population. We need to draw a line. Hilsa fishery is being significantly over-exploited in the West Bengal waters. Strict regulations are needed to curb overfishing,” said Isha Das of Jadavpur University, lead researcher of the study.
Overfishing happens when more fish are caught than the population can replace through reproduction.
Using available data, sample collection and computer modelling, the team estimated 25,440 tonnes as the sustainable yield limit for hilsa fishery annually in northern Bay of Bengal region of West Bengal, while the maximum number of boats that may be deployed to achieve this catch is 3987.
“We wanted to examine how we could increase the catch without impacting the fish stock. So one way was to determine an acceptable limit of fishing with boats as one of the parameters. In practise, there are other factors as well that come into play as oceans and rivers are natural systems and are dynamic in nature,” said Isha Das.
Referring to the West Bengal Government data, the researcher clarified that though in the last several years, except for 2010, the annual catch has remained below 25,440 tonnes, the number of fish removed from the population through interaction with fishing (fishing mortality) has been high and the number of boats have gone up.
“This has had a negative impact on the stock in subsequent years,” said Isha Das.
Currently, the study states, fishing pressure from the number of boats legally deployed is almost three times as much.
When asked about the over-exploitation of the fish in northern Bay of Bengal, a peeved Tajen held the businessmen-fishermen-government nexus responsible. “We fishermen have to make a living somehow and we are operating boats that belong to big businessmen. Each businessman owns about 12 to 13 boats. They are here to make money because hilsa fetches good money because of a drop in stock,” Tajen said.
The state government, he claimed, argues that some boats are lost or wrecked on sea and so new vessels are needed.
The hilsa supremacy
Like the salmon, hilsa live most of their lives in salt water and swim to freshwater and estuarine waters to spawn (release eggs). Hilsa start swimming upstream during the southwest monsoon when the rivers swell. The hatchlings go back to the sea and repeat the cycle. They can cover as much as 70 km in a day.
The species is widespread– ranging from the Persian Gulf, Red Sea, Arabian Sea, Bay of Bengal and Vietnam Sea to China Sea.
The hilsa fishery in India and Bangladesh is dependent on hilsa harvested from a particular area: the Indo-Gangetic and Brahmaputra river basins, said study co-author Sugata Hazra, director, School of Oceanographic Studies, Jadavpur University.
The species breed throughout the year with peak activity in October-November and minor spawning phases in February- March and July-August in various rivers and estuaries in the region. Between July and October, large size groups of fish are abundant in the riverine area.
In general, about 80 to 90 percent of the hilsa is captured during monsoon months (July to October) coinciding with the upstream movement to the rivers and estuaries.
About 95 percent of the catch of this commercially important species comes from India, Bangladesh and Myanmar. Annual average production of hilsa in India is 40,000 tonnes per year. In West Bengal, hilsa is an important component of the state fishery. It accounts for about 11 percent of the total fish landings.
The annual fish catch of hilsa from the Bhagirathi–Hooghly River has fluctuated over the years ranging between 12,733 tonnes and 20,000 tonnes between 2000–2001 and 2010–2012.
Over-exploitation, siltation in riverbeds, dams, a decrease in water flow, pollution and fragmentation of the river in the dry season are key impediments to migration.
A fast swimmer, hilsa has a history of migrating all the way to Allahabad and above in the Ganga river system from Bangladesh. Installation of a barrage in Farakka has completely intercepted the Hooghly-Bhagirathi migratory route of Hilsa since 1975, said Hazra.
Hilsa’s well-being
To shore up supplies, one factor that requires urgent attention is the practice of trapping juvenile hilsa (100 to 150 mm), which according to Isha Das, has stretched on for years and has taken its toll on the overall haul. The stage right after the fingerling phase is referred to as a juvenile.
“Hilsa normally has a life expectancy of four to five years if not fished out. They spawn thrice,” Isha Das said. The juveniles are entangled in fishing gear during their seaward migration.
For four to five months, the juveniles feed in freshwater before they make a move to sea water. They are caught in large numbers using nets of small mesh size during their grazing period in rivers as well as estuaries by artisanal fishermen resulting in indiscriminate killing of these tiny fishes, said Hazra.
“We have told the government that boats are in excess, especially the trawlers, and they should not be allowed. We don’t like trawlers because the nets with small mesh size trap juvenile or baby hilsa that could have become adults and spawned. This results in an overall decrease in catch,” Tajen Das said.
Juvenile hilsa, mostly the by-catch of fishery, is not preferred by the fishermen due to their low market price, Isha Das said.
“Destruction of tiny hilsa and other fishlings are inadvertently brought upon by the prawn and prawn seed collectors using zero mesh nets,” Hazra explained.
She said their study also draws attention to the case of netting first-spawners (270 mm).
“Our analysis of decade-old data shows that the probability of first spawners getting caught in the nets is very high at 75 percent. So you are destroying the opportunity for them to spawn and produce more hilsa,” Isha Das said.
Das said this leaves a stock with a higher proportion old fish, the third time spawner or older than that.
Further, the study also attributes the deterioration in the health condition of hilsa in its natural habitat to overfishing.
“They are not attaining the required length and weight. West Bengal hilsa fishery is targeting smaller hilsa fish that is unsustainable in the long-term,” Isha said.
Tajen also rued the disappearing breeding grounds for the hilsa. “There is no breeding ground for the fish in India. Earlier it used to breed in Uttar Pradesh also. Now the fish that we get comes from Myanmar, moves to Bangladesh and that is what we catch. Our fishermen have to go in illegally to Bangladesh waters often to get a decent catch,” Tajen said.
Gap in enforcement
Following recommendation from the IUCN-led trans-boundary studies on hilsa migration, in which Hazra was a participant, the government of West Bengal issued fresh regulation for hilsa fishery management in 2013 where five hilsa sanctuaries were declared and mesh size and minimum catch size were regulated.
The West Bengal government has imposed a fishing ban during the peak breeding period (between September 15 and October 24) every year and has issued directives on mesh size regulation to protect juveniles.
Putting up bag nets, scoop nets and small mesh gill nets along the migratory route during to February to April each year is prohibited as per government regulations.
“However, this remains to be implemented at the ground level with participation from department of fishery, fishermen association, businessmen and consumers,” said Hazra.
Similarly, Hazra said this restriction of boats and catch in a year (as suggested in the study) should be announced by a fresh notification after thorough discussion with the stakeholders for implementation to meet the Sustainable Development Goal 14, which is mandatory for India as a signatory. The country is committed to protect the oceans and the lives that depend on them.
“The government can marginally modify the figures depending on last two to three years catch data. This will be more scientific. However, initially the limit suggested in the study can continue for four to five years,” Hazra said.
The situation is improving
But things are slowly looking up, according to the state fisheries department, even though there are gaps in enforcement of the rules.
The state government admits that the hauling of juvenile hilsa is a “major problem” as also is the issue of unbridled use of mechanised fishing boats, use of bag nets, drag nets or gill nets with small mesh size (less than 90 mm mesh size).
“For the last few years, we have had substantial catch in the open waters. But we do have a crisis in the sense that the production needs to be ramped up to satiate the demand. The demand has not been estimated but is as much as you can get. We are trying to generate more awareness among the fishermen,” a source in the state fisheries department told Mongabay-India requesting anonymity.
The government is offering alternative employment opportunities and rice at Rs 2 per kg to fishermen during the ban period so they don’t catch the fish.
Decline in hilsa availability threatens the livelihoods of over 26,000 fishermen, the source said, but Tajen asserts it could affect millions in Bengal who are both directly and indirectly dependent on it.
Last year, the floods offered some respite to the fishermen community. “There was a glut of hilsa, particularly in Odisha, following heavy rains in the coastal belt. They swam from the sea to the river mouth to lay eggs. This increase in supply also led to a drop in prices,” Tajen Das observed.
The fisherman highlighted how the implementation of the 22-day ban slapped across the border in Bangladesh to stop catching, selling, transporting and hoarding of hilsa during its peak breeding season has been effective in ramping up supply. Hilsa is Bangladesh’s national fish.
The Bangladesh government has introduced an extensive hilsa management action plan to increase hilsa production not only by conserving the juveniles but also by protecting the brood fish during breeding seasons by imposing a ban on fishing and restricting the mesh size. The Bangladesh Government also offers VGF (vulnerable group feeding) programmes for poor fishermen during the ban period
Tajen batted for better management of hilsa fishery on the lines of Bangladesh’s policies, thanks to which the country has seen an increase in hilsa production at a rate of eight to ten percent every year. This is in contrast to the wane in production in India and other countries.
The popular fish (hilsa of the Padma river) was last year recognised as geographical indication (GI) product of Bangladesh, which recently lifted its export ban on hilsa, whose key market is India.
“The situation needs to improve in India. The fishermen have very limited means to earn money when the ban is imposed. The benefits announced by the government does not reach all sections. They have to pay the boat owners. The trend that we are seeing is most fishermen migrate out of Bengal to coastal states like Andhra Pradesh and Kerala to eke out a living,” Tajen Das claimed.
CITATION:
Das, I., Hazra, S., Das, S., Giri, S., Maity, S., & Ghosh, S. Present status of the sustainable fishing limits for Hilsa Shad in the northern Bay of Bengal, India. Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, 1-8.
Banner image: Dawn at Mandarmani, West Bengal India as the fishermen prepare to launch their boats. Photo by Nilanjan Majumdar/Wikimedia Commons
