Tagged Hilsa Fish Recovery Showed a Migration of 225 Km in River Ganga
ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore in association with National Mission for Clean Ganga (NMCG), Ministry of JalShakti, has been carrying out Hilsa, Tenualosa ilisha fisheries improvement in the river Ganga, since 2020. After construction of Farakka barrage in river Ganga during 1975, hilsa fisheries has significantly impacted even, the production has touched down to zero in the middle stretches of river Ganga (Farakka to Prayagraj, the study stretch). To understand the current migratory pattern of Hilsa in the river Ganga, live fish of average weight of more than 250g are being tagged with FloyT-bar anchor tags. Since November 2020, a total of 391 tagged live hilsa has been already ranched in the river Ganga. An interesting result came on 6th October 2021 (17.30hr), that a fishermen caught the tagged live hilsa at NimaitirthaGhat, Baidybati, Hooghly Dist, West Bengal (220 47' 29.5" N; 880 20' 18.8"E) bearing tagged no CIFRI1516 (inserted pictures), that was ranched on 1st October 2021 (20.00hr) at Farakka (24°48'14.93"N; 87°55'55.69"E). This significant observation showed that the fish has migrated 225 km downstream from the ranching site, within a period of 4d 21h (117.3h). This is to note that, of the 225 km of lower stretch of river Ganga, 95km stretch is a freshwater tidal stretch that shows the river stretch experiences tidal current. Negotiating the tidal current the hilsa migration speed was estimated as @ of 0.56 m/s. In addition, it has been recorded a weight loss of 34 gm during this period of migration (4d 21h). This interesting result is of first kind to record in the migratory fish species in India. However, a deeper scientific study is the need of the hour for this migratory fish. Herewith, we acknowledge all the scientific team members associated with ICAR-CIFRI-NMCG-HILSA project.