Low-Cost Salinity Sensor Increases Profitability and Environmental Sustainability for Small Plot Shrimp Farmers

Over 80% of the world shrimp production comes from developing countries. The nutrient-rich cash crop can provide a small plot entrepreneur with higher revenues than alternative crops; however, the extreme poor are unable to afford the necessary equipment to monitor the salinity concentration in the ponds. Consequently, their yields per volume are on average one-third the amount of their commercial counterparts. This undergraduate research project produced a marketable salinity sensor with the same accuracy as current systems while reducing the total manufacturing and production cost by over tenfold. The handheld sensor uses a resistive bridge to measure salinity. The output is displayed through a bank of LEDs which correspond to corrective measures necessary to maintain the optimal salinity concentration for a high shrimp yield. The sensor is designed to maximize profits and reduce the environmental footprint by effectively managing the addition of salt in ponds. The system is rechargeable through human power and can be assembled and distributed by low income populations in developing countries. The projected marketing cost is less than nine dollars and has the potential to improve per capita incomes by over threefold.