Development of a cloud-based IoT monitoring system for Fish metabolism and activity in aquaponics

Abstract

A cloud-based Internet of things monitoring system in aquaponics is proposed in this study. The system can measure water temperature, water depth, dissolved oxygen, and pH value. Moreover, three infrared distance sensors were attached to the aquarium glass at different heights to monitor the group activity of fish. Continuous water depth sensing in the rearing tank can be used to monitor the ebb-and-flow irrigation and calculate the flowrate of water circulation.By using the fish activity sensing to determine if the fish are at rest, the dissolved oxygen and water temperature at fish’s resting states are collected, then based on the established oxygen transfer rate model in this study, the systemic metabolic rate and fish’s locomotion-induce metabolic rate can be calculated through the daily regression analysis. Fish activity sensing is a proactive measuring method compared with the measuring of dissolved oxygen and pH value, it has the advantage of immediacy and can technically be used to cross check whether the reading of dissolved oxygen or pH sensor near feeding time is within a reasonable range.The measuring module incorporating sensors and sub-1 GHz communication can transmit data to a 1-km-long gateway module. Finally, the data are uploaded to ThingSpeak™, a cloud platform, through Wi-Fi. By using the data stored on the cloud, a real-time alarm system for indicating abnormalities is developed and a periodic regression analysis is conducted using the cloud-based programming of ThingSpeak™.