|Title||A diverse group of echogenic particles observed with a broadband, high frequency echosounder|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Briseno-Avena C., Franks PJS, Roberts P.LD, Jaffe J.S|
|Journal||Ices Journal of Marine Science|
|Type of Article||Article|
|Keywords||acoustic-scattering; biomass; broadband echosounder; cochlodinium-polykrikoides; Fisheries; high frequency; Marine & Freshwater Biology; Marine snow; oceanography; phytoplankton; sound-speed; spatial-distribution; stereoscopic; target strength; thin-layers; video plankton recorder; Zooplankton|
In 1980, Holliday and Pieper stated: "Most sound scattering in the ocean volume can be traced to a biotic origin." However, most of the bio-acoustics research in the past three decades has focused on only a few groups of organisms. Targets such as small gelatinous organisms, marine snow, and phytoplankton, e.g. have been generally to be considered relatively transparent to acoustic waves due to their sizes and relatively low sound speed and density contrasts relative to seawater. However, using a broadband system (ZOOPS-O-2) we found that these targets contributed significantly to acoustic returns in the 1.5-2.5 MHz frequency range. Given that phytoplankton and marine snow layers are ubiquitous features of coastal regions; this works suggests that they should be considered as potential sources of backscatter in biological acoustic surveys.