Research of Bioacoustic Characteristics in the Southern Ocean

Acoustic surveys of biological resources in the Southern Ocean are an important technical means for assessing Antarctic krill resources. However, copepods, polychaetes, jellyfish, pteropods, and other plankton often coexist in krill distribution areas, and their acoustic signals may interfere with krill echo identification and affect the scientific validity of resource assessment. Based on the literature attached to the project application, this paper adopts a narrative review method and summarizes Southern Ocean bioacoustic surveys, the target strength to body length relationship of Antarctic krill, multi frequency mean volume backscattering strength differences, the SDWBA target strength model, and preliminary multi frequency acoustic species identification. The review indicates that studies on the target strength and multi frequency acoustic characteristics of Antarctic krill are relatively mature, and differences between 38 kHz and 120 kHz acoustic images can be used for auxiliary identification. However, quantitative studies on the target strength of coexisting groups such as copepods, polychaetes, jellyfish, and pteropods remain weak, and preliminary multi frequency identification models are still incomplete. It is recommended to strengthen the construction of target strength libraries for multiple groups, standardized equipment calibration, spatiotemporal matching between acoustic and biological sampling, and field validation of multi frequency identification models, so as to improve the accuracy of acoustic surveys and assessments of biological resources in the Southern Ocean.