plSSN : 0374-8111 | elSSN : 2287-8815
plSSN : 0374-8111 | elSSN : 2287-8815
plSSN : 0374-8111elSSN : 2287-8815
Estimation of Target Strength of Emerald Rockcod Trematomus bernacchiiin the Ross Sea, Antarctica
이사라·오우석·나형술1,2·손우주1·김정훈3·이경훈4*
국립부경대학교 어업기술안전연구소, 1한국해양과학기술원 극지연구소 해양대기연구본부, 2과학기술연합대학원대학교 극지과학과, 3한국해양과
학기술원 극지연구소 생명과학본부, 4국립부경대학교 해양생산관리학부
Trematomus bernacchii, a dominant benthic notothenioid in the Ross Sea, plays a key role in Antarctic coastal food webs. It has no swimbladder and its acoustic target strength (TS) fundamentally differs from that of swimbladdered fish. Therefore, species-specific TS estimation is essential when assessing acoustic biomass. This study applied the Kirchhoff Ray Mode (KRM) model to estimate the frequency-dependent TS at 38, 70, 120, and 200 kHz using morphological contour data collected from the Terra Nova Bay polynya in March, 2024. The results show a typical broadside-dominant scattering pattern, with a peak TS near the 0° tilt and decreasing responses at larger angles. At higher frequencies, the increased ka ratios amplified the tilt-angle sensitivity, whereas responses at 38 kHz were comparatively stable across tilt angles. Despite the low to moderate regression fits, this study provides the first frequencyspecific TS relationships for a swimbladderless Antarctic benthic fish species, as well as baseline parameters for acoustic-based distribution mapping and biomass estimation under the CCAMLR ecosystem monitoring framework.
Trematomus bernacchii, Target strength, Kirchhoff Ray Mode model, Ross Sea, Underwater acoustics