Determining dominant scatterers of sound in mixed zooplankton populations.
Determining dominant scatterers of sound in mixed zooplankton populations.
复制标题
确定混合浮游动物种群中声音的主要散射体。
DOI：
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复制
发表时间：
2007
影响因子：
2.4
通讯作者：
N. Copley
中科院分区：
文献类型：
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作者：
A. Lavery;P. Wiebe;T. Stanton;G. Lawson;M. Benfield;N. Copley
高频声散射技术已被用于研究混合浮游动物种群中的优势散射体。在缅因湾测量了43、120、200和420千赫的体积后向散射。利用网络和视频采样技术确定浮游动物的组成和大小，利用电导率、温度和深度传感器确定水的性质。利用最近发展的浮游动物散射模型和微观结构确定了优势散射体。微观结构一般对散射没有贡献。在某些地点，含气浮游动物在所有频率的散射中都占主导地位，它们只占总丰度和生物量的一小部分。在这些地点，声学推断的尺寸与从净样品确定的尺寸非常一致。声学、网络和视频对这些浮游动物丰度的估计之间的显著差异很可能是由于网络和视频技术的限制。没有其他类型的生物散射体在所有频率上都占主导地位。桡足类，一种流体状的浮游动物，占了大部分的丰度和生物量，只在频率最高的特定地点占主导地位。在这些地点，声学推断的丰度与净估计和视频估计非常吻合。描述了解释混合浮游动物种群高频声散射难题的一般方法。
High-frequency acoustic scattering techniques have been used to investigate dominant scatterers in mixed zooplankton populations. Volume backscattering was measured in the Gulf of Maine at 43, 120, 200, and 420 kHz. Zooplankton composition and size were determined using net and video sampling techniques, and water properties were determined using conductivity, temperature, and depth sensors. Dominant scatterers have been identified using recently developed scattering models for zooplankton and microstructure. Microstructure generally did not contribute to the scattering. At certain locations, gas-bearing zooplankton, that account for a small fraction of the total abundance and biomass, dominated the scattering at all frequencies. At these locations, acoustically inferred size agreed well with size determined from the net samples. Significant differences between the acoustic, net, and video estimates of abundance for these zooplankton are most likely due to limitations of the net and video techniques. No other type of biological scatterer ever dominated the scattering at all frequencies. Copepods, fluid-like zooplankton that account for most of the abundance and biomass, dominated at select locations only at the highest frequencies. At these locations, acoustically inferred abundance agreed well with net and video estimates. A general approach for the difficult problem of interpreting high-frequency acoustic scattering in mixed zooplankton populations is described.