Economics of risk and uncertainty of alternative water exchange and aeration rates in semi‐intensive shrimp culture systems

Abstract

Reducing water exchange in shrimp aquaculture to minimize discharge of pollutants is a search for sustainability. In desert regions, like most of northwest Mexico, low water exchange must be complemented with artificial aeration to compensate for low levels of oxygen in warm and highly saline water. The economic yield of a low‐water‐exchange production system is compared against yield from a typical water‐exchange‐without‐aeration system for Penaeus vannamei culture. The difference between two systems is centered on pumping and aeration rates for a 100 ha semi‐intensive farm in northwest Mexico. A bioeconomic model was built to compare the systems. Risk analysis is adopted to account for uncertainty of seed price, shrimp growth rate, survival rate, and shrimp prices. The typical system was slightly more profitable than the low‐water‐exchange, aerated system. The latter used less electricity than the former in all of the three mortality‐rate scenarios. However, the difference in profitability is so small that for practical purposes both production systems provide similar economic yield. For a typical system, the probability of reaching a positive net present value (NPV) is high, therefore under the assumed risks, a 100 ha semi‐intensive shrimp farm in northwest Mexico is a good investment choice.