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

[EN] 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. (C) 2017 Elsevier B.V. All rights reserved.