Can acoustic shadows identify fish species? A novel application of imaging sonar data

  • Langkau M
  • Balk H
  • Schmidt M
 et al. 
  • 54


    Mendeley users who have this article in their library.
  • 19


    Citations of this article.


This study addresses a fish species discrimination method based on normalised elliptic Fourier de- scriptors applied to acoustic shadows derived by Dual-frequency Identification Sonar (DIDSON). Acoustic shadows of templates (20, 30, 40 and 50 cm) and live fish of four species [bream, Abramis brama (L.); barbel, Barbus barbus (L.); chub, Leuciscus cephalus (L.); and trout, Salmo trutta (L.)] were projected on a plate in an experimental set-up and tested on suitability for species discrimination. Twenty-centimetre templates were cor- rectly classified in 97.5% of the cases, indicating a size threshold. The larger templates reached values of 100% correct classification based on cross-validated discriminant function analysis. It was also possible to classify moving fish based on screenshots of their acoustic shadows with a certainty of 83.9%. Extended field tests are required to evaluate the method for use in practical monitoring applications in multispecies river environments.

Author-supplied keywords

  • Acoustic shadows
  • Discriminant function analysis
  • Fish species discrimination
  • Fourier analysis
  • Hydroacoustics

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • M. C. Langkau

  • H. Balk

  • M. B. Schmidt

  • J. Borcherding

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free