Evaluation of Fish School Resources in Shallow Sea Based on Echo Statistic Method

In order to obtain the spatial-temporal distribution of fish resources together with its changes in sea ranching, and realize the acoustic monitoring and evaluation of fish resource proliferation in sea ranching, the acoustic evaluation technology of fish resources based on the echo statistics method is researched in this paper. Firstly, the simulation is conducted by constructing the fish school echo signal based on the Kirchhoff-ray model, and the simulation results show that the echo statistics method is suitable for acoustic monitoring of fish stocks in sea ranching. Then, the self-developed fish finder was used to survey the national sea ranching demonstration area in the western waters of Furong Island in Shandong Province by navigating in November 2020 and March 2021 respectively. The data obtained from the two voyages were post-processed using the echo statistics method, and the density changes and activities of the fish schools in different times and regions in the surveyed sea were obtained. The analysis results show that the echo statistics method is suitable for the monitoring and evaluation of fishery resources in the sea ranching area.