On acoustic multi-frequency species identification and separation of Atlantic mackerel, Norwegian spring spawn herring and Norway pout.
Abstract
The accuracy of the multi-frequency species identification and separation algorithms may be significantly
improved when the detailed acoustic scattering characteristics of the fish are known, including its expected
variability and uncertainty. The modeling approach is effective for interpreting measured data collected for
different fish species and may give a better understanding of the acoustic scattering characteristics. The paper is
motivated by development of algorithms of multi-frequency species identification and separation of three
economically valuable North European fish species: Atlantic mackerel, Norwegian spring spawn herring and
Norway pout. The backscattering by these fish is studied using an advanced modeling approach, and the results
of the analysis are compared with selected multi-frequency recordings. This allows for an explanation of the
main backscattering mechanisms over the selected frequency range and often a better understanding of the
dominating acoustic scattering parameters. The impact of fish orientation behavior, pressure (for herring) and the
morphological state of the fish is also discussed. Typical backscattering frequency responses for herring,
mackerel and Norway pout are explained theoretically. The obtained results may be a base for improving the
automatic identification algorithms now introduced in scientific echo sounder post-processing systems.
Publisher
ICESSeries
ICES CM documents2004/R:18