中层带单个散射体的频率和深度依赖目标强度测量

Frequency- and depth-dependent target strength measurements of individual mesopelagic scatterers.

作者信息

Bassett Christopher, Lavery Andone C, Stanton Timothy K, Cotter Emma DeWitt

机构信息

Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA.

Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543,

出版信息

J Acoust Soc Am. 2020 Aug;148(2):EL153. doi: 10.1121/10.0001745.

DOI:10.1121/10.0001745

PMID:32873032

Abstract

Recent estimates based on shipboard echosounders suggest that 50% or more of global fish biomass may reside in the mesopelagic zone (depths of ∼200-1000 m). Nonetheless, little is known about the acoustic target strengths (TS) of mesopelagic animals because ship-based measurements cannot resolve individual targets. As a result, biomass estimates of mesopelagic organisms are poorly constrained. Using an instrumented tow-body, broadband (18-90 kHz) TS measurements were obtained at depths from 70 to 850 m. A comparison between TS measurements at-depth and values used in a recent global estimate of mesopelagic biomass suggests lower target densities at most depths.

摘要

基于船载回声测深仪的最新估计表明，全球鱼类生物量的50%或更多可能栖息在中层带（深度约200 - 1000米）。然而，由于基于船只的测量无法分辨单个目标，对中层带动物的声学目标强度（TS）了解甚少。因此，中层带生物量的估计受到的限制很大。使用一个装有仪器的拖体，在70至850米的深度获得了宽带（18 - 90千赫）TS测量值。深度TS测量值与最近全球中层带生物量估计中使用的值之间的比较表明，在大多数深度目标密度较低。