Although Bangladesh has succeeded in freshwater fish production and in protecting hilsa, scientists warn that the amount of fish in the Bay of Bengal is falling and some marine species are close to depletion.

There are fears that unless indiscriminate, unregulated and illegal fishing stops, the Bay of Bengal could be left without fish in future. Researchers have made this assessment through marine fisheries research and surveys.

There is no accurate estimate of fish stocks in Bangladesh's waters, and no limit set on how much fish may be caught, because marine fisheries survey research was halted for nearly two decades.

Surveys began after a new vessel, R.V. Meen Sandhani, was bought in 2016. They are carried out in the continental shelf area at depths of 10-200 metres.

A report on marine fish based on an analysis of the past three years' data has been sent to the upper levels of government. Md Sharif Uddin, chief scientific officer of the Marine Fisheries Survey Management Unit of the Department of Fisheries, said: "After 2000 our vessel-based research was completely halted. It has been restarted through the Bangladesh Marine Fisheries Capacity Building project."

"We started this mainly in 2016. From three years of preliminary data we see that although the overall stock in our sea is fine, some fish in some cases appear to have been overharvested."

Marine scientist Saidur Rahman Chowdhury, who is involved in research on the state of marine fish resources and in analysing the data from the survey vessel R.V. Meen Sandhani, said: "This is very worrying for our scientific community. If we do not leave enough fish for them to breed, there will be no reproduction in the next season."

"Other seas of the world, such as the Gulf of Thailand, have become largely empty of fish. We do not want our Bay of Bengal to become empty of fish like that."

Among marine fish, stocks and quantities of lakkha, sardine, poa, lotia, foli chanda, horina shrimp and kata species have fallen at an alarming rate.

Source: BBC Bangla. First published in Bengali on The Agro News.