Implementation of an Optical Sensor to Detect Fish in Aquiculture Tanks

The increase in the world population increments the demand for fish. In this context, the fish farms have to improve the production in their infrastructures being this very expensive. In this paper, we propose a Low-Cost Wireless Sensor Network based in an optical sensor, for monitoring the presence of sea breams at different distances. In addition, we use a test tube with foil to simulate the similar characteristics of this kind of fishes to perform the tests. We evaluate the use of a light-dependent resistor and a photodiode for the infrared spectrum to detect the object at different distances. Our results indicate that the best is the photoresistor because its data was more accurate than the photodiode. In the experiment, we locate the simulation of fish at different distances of 5 cm, 9 cm, 10 cm, 15 cm, 17 cm, 26 cm, and 37 cm. We measure at different points of the tank measuring the data triplicate. The results displayed that the maximum resistance is 15.44Ω when the test tube is located near the photoresistor and the minimum 10.39Ω when the tube is located far away from the photoresistor. Finally, we perform a test using a real fish that we thought in front of the photoresistor. The results show that when fish is in front of the photoresistor, the maximum resistance is 15.45Ω (with fish) and minimum resistance of 6.42Ω (without fish). We concluded that we are able to distinguish the presence of fish at different distances using light demand resistors.