Stocking for sustainable aqua-venture: optimal growth, yield and economic analysis of Penaeus vannamei culture in inland saline water (ISW) of India

Inland saline water (ISW)-based Penaeus vannamei aquaculture system is an emerging field of fisheries, which came as a magic capsule to boost the overall agri-cum-aquacultural economy of many countries including India. The standardized technology for ISW-based P. vannamei culture includes ameliorating the culture water with K+-ion supplementation and amending Ca++/Mg++ ratio to 1:2–3, so as to simulate the natural seawater (NSW) equivalence, and replicating the NSW-culture parameters in the ISW system. However, for sustained growth and enhanced profitability, there was a need for formulation of ISW-specific culture parameters. In view of this, the present study was undertaken wherein P. vannamei seeds (post-larvae 8) were experimentally reared in ISW ponds with three different stocking densities (30, 45 and 60 PL8/m2) for a period of 75 and 110 days across two culture seasons followed by evaluation of growth and economic performances. Our study revealed highest mean weight (21.21–28.10 g), specific growth rate (8.75–6.22%) and survival percentage (92.93–90.34%) and lowest feed-conversion ratio (1.14–1.21) in the 30/m2 stocking group over the two respective seasons. The lower stocking density group also displayed maximum economic viability, recording benefit–cost ratio of 2.01 and net profit of 2.73 USD/Kg at 110 days. Further, in terms of profit sensitivity it ensures comfortable margins at any uncertain inflationary/deflationary scenarios. Thus, it can be inferred that at 30/m2 stocking density, the ISW-based P. vannamei culture can become a financially viable and sustainable aqua-venture for aspirant farmers, which have the potential to transform salt-degraded wasteland into profit-making asset.