Sustainable fish production through ecological and fisheries management of canals in Indian Sundarbans (West Bengal).

Abstract

The canal systems in Indian Sundarbans, West Bengal cover 907.33 ha area and offers a huge resources for fisheries development and livelihood. Naturally, fish enter to these canals from the source waters and form natural populations. Despite having vast resources, a little attention is paid to boost Inland fish production from canals. To understand the ecology and development of suitable practices/ techniques in canal systems, an effort was made for the sustainable fish production. Bharua canal a tidal fed canal connected with river Hooghly at Shibpur, Fraserganj of Sundarbans was selected to enhance fish production. The total length of canal is 2 km, average width of 45 m and water depth ranged from 3 to 8 feet. Three numbers of net partition system (NPS) were constructed with dimension of 50m × 45m covering an area of 2,250 m2 each partition system. Water temperature (27.50±0.49°C), transparency (27.71±2.10 cm), Dissolved oxygen (5.61±0.13mgL- 1), pH (7.68±0.04), salinity (2.28±0.11gL-1) were recorded during the trial. Diatoms (Bacillariophyceae) were dominated across the seasons. The quantitative abundance of phytoplankton and Zooplankton in the canal was 9522±2170 cellsl-1 and1918±97ind/l respectively. Rotifera shared dominance (45%) followed by crustacean nauplii (20%) and cladocera (12%). A total of 16 species of fish under 7 orders and 10 families were recorded. With the native fishes, fingerlings of Indian Major Carps Labeo catla, Labeo rohita and exotic carp Ctenopharyngodon idella were stocked @2 nos./m2 in a ratio of 50: 40: 10 in a net partition system (NPS) installed in the canal. After a culture period of 180 days, the average size recorded for Labeo catla, Labeo rohita and Ctenopharyngodon idella were 265.61 ± 25.44 g, 184.63 ± 26.13 g and 221.57 ± 21.94g respectively. In addition to stocked fishes, considerable quantity of small indigenous fish (SIF’S) like Puntius sophore, Puntius ticto, Amblypharngyodon mola, Salmostomo bacaila were caught from NPS. In the present study, culture of fish in NPS showed feasible option in the canal. Hence, the NPS can be look upon as a potential culture practice to enhance the fish production and productivity from the unutilized canal resources. Adoption of this culture practice will provide a nutritional security, generate employment opportunity, and improve the livelihood and socioeconomic status of the rural populace of Indian Sundarbans.