Detection and target strength measurements of uneaten feed pellets with a single beam echosounder

The possibility of detecting uneaten food pellets in aquaculture floating cages using a scientific single beam echosounder is demonstrated. The applied methodology is based in a basic scheme with the ultrasonic beam facing upwards the sea surface from the cage bottom. The target strength of single pellets is measured resulting in a linear relationship between target strength and pellet size. These results are the basis to quantify the uneaten food falling and to develop an automated feeding system based on demand.