Hilsas may not be taken for granted

Reports expressing concern about the country's national fish, hilsa, appeared in the media from time to time over the past few years.And those were about if hilsa stock was depleting due to overfishing or any alteration in the conditions that support hilsa's spawning and growth in our rivers. A scientific study done in 2015 found increased salinity, low water flow in the country's major rivers, water control structures built in the rivers, increased siltation and river pollution as the possible causes of fewer hilsas in our rivers. Being an anadromous species of fish (as it spends parts of its life cycle in salty as well as fresh water), hilsa migrates up rivers from sea to spawn. But the factors as noted in the foregoing may come in the way of their migratory behaviour. Also, changes in the temperature of river water (which may have to do with climate change), fall in the level of oxygen in water (pollution may be the cause) and so on can affect their migration. Experts were of the view that the rise in the river water's salinity might be hindering hilsas' migration to the rivers in a big way. These were the possible causes suggested by experts to explain any sustained decline in the hilsa population in our rivers. However, the amount of hilsa caught may fluctuate over time. So, without observing the hauls over a long period of time, it would be too early to reach any conclusion about any lasting change in hilsa's migratory movement towards the estuaries of Bangladesh's major rivers.
There was yet another concern about the size and weight of the hilsas caught. In fact, after 2019, when the country is said to have witnessed the best time for both the fishermen who make a living by catching hilsa and those who trade in the fish, the situation changed for the worse. According to the Department of Fisheries (DoF), for three years since that time (2019), the hilsas were found to be lighter by about 200 grams than those caught earlier. Obviously, their size was also smaller. However, further observations by DoF and Bangladesh Fisheries Research Institute (BFRI) came up with some good news, too. Reports have it that since the beginning of this month, most of the hilsas caught in the major rivers like Padma, Meghna and Jamuna were bigger in size and, of course, heavier, weighing up to one kilogramme. And what is further heartening is that there has been a phenomenal increase in their number. The three year-long lean period for hilsa, which experts believe was due mainly to reduced rainfall, is over.
It would, again, be too early to enthuse over this July's bigger hilsa hauls. It may well be another cycle of change in its migratory pattern that this beloved fish of Bengali people has been experiencing of late.
Hilsa, a kind Indian herring, is no more found in large numbers in the estuaries of the rivers flowing into Bay of Bengal. It has also been a very popular fish in the neighbouring Myanmar. But in recent decades, the hilsa stock of that country has dwindled. Though Bangladesh gets 60 per cent of the world's total catch, hilsa was once Myanmar's most exported fish caught in the wild with between 15 and 20 per cent of the catch. But the fish is no more available in amounts that Myanmar's fishermen experienced in the past. The decline in the stock, they largely blame on overfishing.
But it was also the case in Bangladesh in the not-too-distant past. Thanks to the restrictions placed on fishing during certain periods of the year, creation of a number of hilsa sanctuaries and other measures taken towards hilsa conservation, the situation has shown some improvements in Bangladesh.
Even so, concern remains and there should be no room for complacency.

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