The Dakshina Kannada and Udupi districts of Karnataka are bestowed with extensive estuarine areas, which is a lifeline for small scale fishermen. Of the many brackish water fish species available in the area, Sillago sihama (Family: Sillaginidae) commonly known as Indian sand whiting or ladyfish is a highly esteemed delicacy and it forms 70 - 80% of the Sillaginid catch of the two districts. There is considerable demand for this species throughout the year but the peak demand is observed during the South-West monsoon when the deep sea fishing is mostly suspended due to rough sea conditions wherein it fetches a maximum price of Rs.700/kg. An abundance of the seed of this species in the estuarine waters of these districts holds prospects of mariculture in cages and ponds. Though attempts to breed S. sihama in captivity were successful in a few research settings, the larval survival was very poor, thereby necessitating further research. Obtaining water quality data from the nursery grounds will throw some light on the optimal parameters to be maintained in the hatchery so as to get the best larval survival rate and growth. Apart from this, 24-hour monitoring of water quality gives an idea as to how the parameters fluctuate within a day in that particular brackish water environment.
Water quality can be monitored continuously by means of industrial grade sensors which require minimum maintenance. It can be used as part of a larger system to provide users with accurate and reliable data. The system can be connected to the cloud so the data can be accessed from remote locations. This allows fish farmers to monitor the water quality of the fish farm from anywhere on the globe. Since fishes are very sensitive to their environment, small changes in water quality parameter can affect the health and growth rate of the fish, thereby affecting the productivity of the fish farm. By using Field programmable gate array (FPGA) as the controller unit for the sensors, it is possible to extend the system after deployment if required. FPGA's consume very less power and has high flexibility which makes it suitable for the circumstances. Technologies such as Bluetooth, Wi-Fi, Zig-Bee and Long Range (LoRa) can be investigated as a communication platform between remote and control system. Depending on the range offered by wireless technologies, an appropriate platform for communication can be decided. Since FPGA offers great concurrency, all the sensor data can be accessed simultaneously making the system real-time.
By designing an FPGA based water quality monitoring system with industrial grade sensors, aquaculturist can be benefited considerably. Monitoring of the fish farm can be done remotely thus alleviating the life of fish farmers. A non-laborious, automated and power efficient system can be developed with FPGA and state-of-the-art wireless technologies. The principal purpose of this work is to develop an affordable and efficient remote water quality monitoring system for the aquaculture industry.