IMPACT OF DROUGHT ON HATCHERY FISH SEED PRODUCTION IN WEST BENGAL - A CASE STUDY

Abstract

Alteration in seasonal and annual variability in rainfall resulting in drought and flood will be significant drivers of change in aquaculture and inland fisheries for the coming years in India. West Bengal a major producer of inland fish seed and consumable fish , is likely to be affected by the climatic changes.With this background the present study was undertaken to assess the impact of drought in the year 2009 on fish seed production in hatcheries of two major fish seed producing districts of West Bengal viz., N 24 Parganas and Bankura. During 2009 the mean minimum air temperature in N 24 Parganas and Bankura, during January-April and May-September was higher by 0.34o C and 0.54o C and by 0.26o C and 0.28o C respectively. The corresponding mean minimum water temperature during the same period in the two district also increased by 0.39 and 0.62o C and by 0.30 and 0.32o C respectively. The optimum fish breeding months, JuneSeptember had a deficiet rainfall of 24% in N 24 Parganas and 15% in Bankura. Majority of the hatcheries investigated (68%) were affected by cumulative effect of high temperature and water deficiency. In N 24 Parganas the major factor for low spawn production was high larval mortality (45%) while in Bankura low demand of fish seed due to inadequate water area for stocking (80%) compelled restriction in purchase of seeds from the hatcheries. Economic analyses of spawn production in the two hatcheries one each in N 24 Parganas and Bankura indicated 61% and 73% loss in income respectively compared to the year 2006. The adaptation options practiced by 90% of the farmers were diversification to culture of alternate species like Pangasius sp., Puntius javanicus, Clarias gariepinus and Piractus brachypomus (paku) and cross breeding of the Indian Major Carps in 55% of the hatcheries.

Key words : Drought, climate change, hatchery, adaptation, breeding season, Indian major carps