Fisheries of Indian Shad (Tenualosa ilisha) in the Hooghly–Bhagirathi stretch of the Ganga River system

Abstract

Tenualosa ilisha, the Indian Shad, is one of the most important commercial fish of the Indo-Pacific region and the Hilsa fishery in India is dependent on this species. Presently, the fishery resource of the species lies largely within the Bhagirathi–Hooghly component of the Ganga River system. The annual fish catch of Hilsa from the Bhagirathi–Hooghly River has fluctuated over the years ranging between 12,733 and 20,000 t between 2000–2001 and 2010–2012. The monsoon migration of Hilsa commences in July and gradually picks up in August. From September onwards, the magnitude of migration to the freshwater system showed a declining trend. Stretches between Nischintapur and Diamond Harbour downstream, Hooghly Ghat and Kalna in the freshwater tidal zone, and Lalbagh to Farakka in the Bhagirathi River have been delineated as potential breeding grounds for Hilsa. The intense fishing pressure in the coastal estuarine zone almost year round, especially in breeding season, adversely affects the breeding migration, spawning, and recruitment success vis a vis overall fishery of Hilsa in the system. There is an immediate need to implement effective conservation measures to protect breeders, potential breeding grounds, and juveniles for the cause of sustainable Hilsa fishery.

Transmission and Toxigenic Potential of Vibrio cholerae in Hilsha Fish (Tenualosa ilisha) for Human Consumption in Bangladesh

“…Hilsha ( Tenualosa ilisha) is anadromous in nature, migrating from the Bay of Bengal to inland freshwater through rivers on the Indian sub-continent for spawning, which occurs from July to October and again from January to March (Ahsan et al, 2014 ) (see Figure 1 ). The upstream migration of Hilsha is associated with the state of sexual maturity, as well as the volume of freshwater discharge from the estuary during monsoons (Bhaumik, 2017 ). The catch percentage of Hilsha is very high during these migratory periods.…”

Role of lunar phases, rainfall, and wind in predicting Hilsa shad (Tenualosa ilisha) catch in the northern Bay of Bengal

“…According to Ahsan et al (), moderate water velocities facilitate the movement of Hilsa shad. Apart from water current, high turbidity also facilitates Hilsa movement, as the shoals of brood Hilsa are found to be attracted by high turbid waters (Bhaumik, ). Thus, we hypothesize that the synergistic effect of favorable water currents and turbidity can lead to higher Hilsa catches.…”

“…According to Ahsan et al (2014), moderate water velocities facilitate the movement of Hilsa shad. Apart from water current, high turbidity also facilitates Hilsa movement, as the shoals of brood Hilsa are found to be attracted by high turbid waters (Bhaumik, 2017 during breeding since the larvae as well as the juveniles cannot thrive well in higher salinity waters (Bhaumik & Sharma, 2012).…”

Interplay between reproduction and age selective harvesting delays of a single population non-autonomous system

“…During the first year, the growth is roughly at the rate of an inch per month [25]. The spawning of Hilsa is seasonal [5] and is observed during July-August to October-November [37]. It takes 8-9 months for hilsa to grow to 163-225 mm in size.…”