High-value fish stock depletes
The stock of some high-value sea fish species has depleted over the last three decades due to excessive fishing that also damages the ecosystem of the marine environment, threatening survival of other aquatic lives.
The depletion trend of some fish populations, including shrimp, pomfret, croaker and Indian Salmon, is so alarming that experts call for urgent protective measures.
"The overall shrimp biomass trend has been consistently downward over the last 30 years and somewhat depleted due to overfishing," said a government report, titled Marine Fisheries Survey Reports and Stock Assessment.
The report was published in 2019, after a three-year (2016-2019) survey by the Department of Fisheries (DoF).
The report recommended immediate government interventions before fish like shrimp, pomfret and Indian Salmon face "commercial extinction".
Two years on, the relevant ministries and departments are yet to formulate the rules needed to stop overfishing and rebuild the stock of endangered fish species.
Kh Mahbubul Haque, additional director general of DoF, said the coronavirus pandemic had slowed down their work.
THE DEPLETION
Though the overall shrimp production has risen due to inland shrimp farming, the total catch of marine shrimp has dropped by about 10,000 tonnes in a decade, according to the statistical yearbooks of the DoF.
In 2009-10, the total catch of marine shrimp was 52,592 tonnes. It dropped to 42,816 tonnes in 2019-20.
The DoF is yet to publish the Fisheries Statistical Yearbook for 2020-21.
Dividing marine shrimps into four categories -- tiger, brown, white and others -- researchers analysed the data of industrial catches of shrimps from 2005 to look into the status of shrimp stocks.
They found that two most high-value shrimp species -- tiger shrimp and brown shrimp -- declined slowly but steadily. On the other hand, the catch of white shrimp increased sharply in 2013 after showing a downtrend for several years. Then it dropped again.
"For the overall shrimp trend, the rising trend in lower-value species is offsetting the declining trends in more valuable groups," reads the survey report.
Pomfret -- another high-value fish -- is also depleting at an alarming rate.
Its catch in 2009-10 stood at 50,245 tonnes. A decade later, it came down to 10,023 tonnes, nearly a five-fold drop, according to the DoF.
Indian Salmon, locally known as Lakkha, seems to be the worst victim of over-exploitation. Its catch fell by a whopping 44 folds in 10 years -- from 7,733 tonnes in 2009-10 to just 177 tonnes in 2019-20.
"The marine fisheries resources are heavily exploited, with some species severely depleted and are in urgent need of rebuilding," the report said.
The overall catch of marine fish, however, increased to 6,71,104 tonnes in 2019-20 from 5,17,282 tonnes in 2009-10.
Experts said the increase in the catch of hilsha and some small fish contributed to the overall rise in the marine fish production. For example, the total marine hilsha catch in 2019-20 was 3,04,566 tonnes, almost half the total marine catch that year. Whereas, the hilsha catch was 1,98,574 tonnes 10 years ago.
"The overall catch, all species combined, may remain the same or increase in spite of intense fishing. This may results from replacement of larger, slower growing and reproducing groups such as Indian salmon with small-sized, fast growing and reproducing species such as sardines and scads," reads the survey report.
Pointing out how overfishing puts negative impacts on the ecosystem, researchers said they noticed small and low-value fish species that used to be forage of big fish are being netted in large volumes in recent years.
"The increase in these small species reflects a significant alteration to the ecosystem structure which may or may not be reversible in a reasonable time period," the report noted.
Prof Sayedur Rahman Chowdhury of the Institute of Marine Sciences and Fisheries of Chittagong University was involved in the study.
He said some recent interventions like enforcing a ban on marine fishing for about 65-days and brood Hilsha were bringing some success.
"But to recover fish stock fully we assume that we need to wait for another 10 to 15 years," he said, pointing out that it took 45 years to recover the stock of cord fish in Europe.
LEGAL LOOPHOLES
While the catch of valuable marine fish has declined, the number of boats and trawlers fishing in the bay increased significantly. In 2019, there were 67,889 industrial trawlers and artisanal boats, up from 45,377 in 2009.
One DoF official said industrial fishers often took advantage of the loopholes in the Marine Fisheries Ordinance, 1983, making it difficult to take legal action.
The ordinance, for example, does not specify the size of an industrial fishing trawler. As a result, when officials seek to ban fishing trawlers of a certain size they consider to be industrial, they cannot prove it in court.
"Whenever we took actions, fishing industry people challenged them in the High Court and secured injunction orders in their favour," the official said, requesting anonymity.
Last year, the government passed the Marine Fisheries Act addressing the loopholes, but the law cannot be enforced without relevant rules.
"The industrial trawlers catch a good amount of large hilsha fish from the sea. It threatens the effort to rebuild the hilsha stock. Rules are being framed to ban industries from catching hilsha fish," the official added.
Officials are also planning to set a limit on industrial and artisanal fish catch.
Meanwhile, the DoF has drafted a Fisheries Management Plan (FMP) detailing the work plan to restore the fish stock. The draft is awaiting approval from the fisheries ministry.
Contacted, Towfiqul Arif, additional secretary (planning) of the fisheries and livestock ministry, said they received the draft before Eid-ul-Adha. "We will look into it."
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