Study of salinity infiltration in soil due to vannamei shrimp farming in the adjoining area of Contai, Purba Medinipur, West Bengal, India and its immediate economic effect

Brackish water aquaculture (presently vannamei shrimp farming) has been increasing rapidly due to gain of higher profits than traditional agriculture or fishery in the coastal areas and it has been playing important roles on the socio-economic development of Contai under Purba Medinipur district of West Bengal, India. It provides quick economic benefits with earning of foreign currency and simultaneously alleviates poverty through employment-generation, creates scope of engagement for the rural and marginal villagers. Although vannamei shrimp farming has contributed a positive impact on the socio-economic scenario of the area, nevertheless has always been subjected to lots of negative environmental consequences as well as thousands of questions regarding crop-productivity, future food-security and challenges towards sustainable development. Substantial leakage, seepage, and overflow of saline water into the nearest agricultural lands has been diminishing the fertility and crop-productivity. As a result, areas of agricultural land are being reduced and land-conversion to shrimp farms is increasing the rise. The rapid increase of farming area has direct and indirect effect especially on agriculture. Moreover, due to continued shrimp farming in the same plots the soil properties of those ponds along with species composition have been changing and those lands are badly becoming barren. As an immediate effect, yield of shrimp as well as income from this sector is reducing with each year.