This study used hydroacoustic method to identify the vertical and horizontal distribution of Antarctic silverfish in the Ross Sea, Antarctica. In February and December 2018, Antarctic silverfish was detected up to 250 meters, and was mainly distributed in water depths of 20 to 30 meters. The horizontal distribution of Antarctic silverfish was mostly undetected in February, and December showed a relatively stronger distribution than that of February. Antarctic silverfish is characterized by their distribution near sea ice.
In this study, the target strength for multi-frequency (38 kHz, 120 kHz, 200 kHz) of juvenile silverfish (Pleuragramma antarcticum) was estimated using by the KRM (Kirchhoff-ray mode) model. The body shape of the silverfish was described by a picture and the body length of nine individuals ranged in 1.8 cm to 8.8 cm. The maximum TScm according to the total length for the constant term (b20) was – 92.93 dB at 38 kHz, – 86.63 dB at 120 kHz, and – 85.89 dB at 200 kHz, respectively. The averaged TScm according to total length for the constant term (b20) was – 100.0 dB at 38 kHz, – 93.0 dB at 120 kHz, and – 106.9 dB at 200 kHz, respectively.