Monitoring Two Typical Marine Zooplankton Species Using Acoustic Methods in the South China Sea.

Abstract

The broadband scientific echosounder is considered to have great potential for zooplankton monitoring. In this study, two common types of zooplankton in the South China Sea, <i>Rhopilema hispidum</i> and <i>Acetes chinensis</i>, were continuously monitored using a broadband scientific echosounder. The results revealed distinct volume scattering strength (SV) spectral characteristics between the echoes of <i>R. hispidum</i> and <i>A. chinensis</i>. Meanwhile, echoes of <i>R. hispidum</i> and <i>A. chinensis</i> were classified using the k-means clustering algorithm, achieving an 83.4% accuracy rate. The SV value at a nominal frequency of <i>R. hispidum</i> changes more sharply than that of <i>A. chinensis</i>, suggesting that the density of <i>R. hispidum</i> changes more dramatically. This study demonstrates the advantages of monitoring <i>R. hispidum</i> and <i>A. chinensis</i> outbreaks with a broadband scientific echosounder.