کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6383999 | 1626418 | 2016 | 6 صفحه PDF | دانلود رایگان |
Volume backscattering strength (Sv in dB re 1Â mâ1) of ice krill (Euphausia crystallorophias) was observed at two frequencies (38 and 120Â kHz) with a calibrated split-beam echosounder system in the Amundsen Sea coastal polynya. The horizontal and vertical scattering layers in the upper 200Â m of the water column were known with the existence of predominant ice krill (>95%) in this region. Acoustic identification using a two-frequency dB window between Sv at 38 and Sv at 120Â kHz separated echoes originating from dominant ice krill from other zooplankton species. The frequency dependence of ice krill at 38 and 120Â kHz was examined and the result presented that ice krill might have different acoustic characteristics from other Southern Ocean zooplankton species including Euphausia superba. This result could be applied to improve the ability of acoustic identification and precise density estimation of ice krill in the high-latitude coastal waters of Antarctica.
Journal: Deep Sea Research Part II: Topical Studies in Oceanography - Volume 123, January 2016, Pages 86-91