01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-02-0345 |
| Title of Abstract | One-year dynamics of sound scattering layers in the central Seychelles⿿Chagos Thermocline Ridge, Indian Ocean |
| Authors | Jihoon Jung*, Dongha Kang, Fredrich Simanungkalit, SungHyun Nam, Dong-Jin Kang, Myounghee Kang |
| Organisation | Gyeongsang National University |
| Address | 123, Hansil 7-gil, Tongyeong-si, Gyeongsangnam-do, Republic of Korea Tongyeong, Gyeongsangnam-do, Korea, Rep. Pincode: 53064 E-mail: dbat1@gnu.ac.kr |
| Country | Korea, Rep. |
| Presentation | Oral |
| Abstract | Covering about 20% of the world⿿s ocean surface, the Indian Ocean strongly influences climate⿿ocean interactions and supports diverse marine life. One of its major upwelling regions, the Seychelles⿿Chagos Thermocline Ridge (SCTR) in the southwest Indian Ocean, is notable for its high biological productivity. Sound scattering layers (SSLs), composed mainly of micronekton, are ubiquitous in the global ocean and play a key role in marine ecosystems. In the Indian Ocean, SSLs exhibit distinct dynamics; however, their long-term temporal characteristics remain poorly understood in the SCTR. To investigate the temporal variability of SSLs, including diel vertical migration, over a one-year period in this region, an Acoustic Zooplankton Fish Profiler (ASL, Canada) was moored at 65°E, 8°S from June 2024 to April 2025. Acoustic backscatter at 38 and 120 kHz was recorded to depths of 360 m, and a temperature⿿depth sensor (DST centi-TD, Star-Oddi, Iceland) was also deployed. Together, these long-term acoustic and environmental observations provide critical insights into the temporal dynamics of SSLs in the SCTR. |
| Are you part of IIOE-2 endorsed project | yes |
| Endorsed Project Number | IIOE2-EP52 |
| Keywords | Sound scattering layer; temporal dynamics; Seychelles-Chagos Thermocline Ridge; Long-term acoustic monitoring |
| For Awards | no |