NEW DELHI: In June 2016, someone forked out Rs 22,000 for a 4 kg hilsa in Bengal’s Howrah. The fish, that had swum down from Myanmar, was indeed a prize catch: it’s rare to find hilsas that large. But the price the shining fish fetched at a bustling wholesale market in Howrah was the ultimate gastronomic measure of how far a fish lover would go to have the bony hilsa on his plate.Now, after a gap of over 40 years, the hilsa will be able to swim down the Ganga all the way up to Allahabad this monsoon .The migration of Hilsa till Allahabad had been possible till a barrage was built across the Ganges at Farakka in Bengal in the 70s. The barrage came with a navigation lock that blocked the free movement of Hilsas.This lock has now been redesigned to ensure smooth and safe migration of the hilsa shoal during the three mating seasons, particularly during monsoon. A navigation lock is a device that is used to raise and lower boats and ships between stretches of water on a river.“We will open the gates for only eight metres and between 1 am and 5 am, which is the preferred time when Hilsa seeks passage. This provision has been made in consultation with ICARCentral Inland Fisheries Research Institute, Central Water Commission and Farraka Barrage Project Authority. We have designed this inhouse and have saved about Rs 100 crore,” Inland Waterway Authority of India (IWAI) vice-chairman Pravir Pandey told TOI.Hilsa has a history of migrating from Bangladesh to Allahabad down the Ganga. Though it’s a salt-water fish, it migrates from the Bay of Bengal to the sweet waters of the Ganges. “Fish often disperse widely over large areas while feeding and spawning. This hilsa migration will lead to an increase in its production in the region. This will also increase the river’s biodiversity and boost the economy of local fishermen,” a shipping ministry spokesperson said.In recent years, overall catch of hilsa has reduced as overfishing, pollution and spawning have taken their toll on fish stocks. The navigation lock being built at a cost of Rs 361 crore as a part of Jal Marg Vikas Pariyojna will be operational from June.Read this report in Bengali