Naval Information Warfare Center Pacific, San Diego, California 92152, USA.
Centre for Research into Ecological and Environmental Modelling, School of Mathematics and Statistics, University of Saint Andrews, United Kingdom.
J Acoust Soc Am. 2020 Feb;147(2):698. doi: 10.1121/10.0000596.
Minke whales were acoustically detected, localized, and tracked on the U.S. Navy's Pacific Missile Range Facility from 2012 to 2017. Animal source levels (SLs) were estimated by adding transmission loss estimates to measured received levels of 42 159 individual minke whale boings. Minke whales off Hawaii exhibited the Lombard effect in that they increased their boing call intensity in increased background noise. Minke whales also decreased the variance of the boing call SL in higher background noise levels. Although the whales partially compensated for increasing background noise, they were unable or unwilling to increase their SLs by the same amount as the background noise. As oceans become louder, this reduction in communication space could negatively impact the health of minke whale populations. The findings in this study also have important implications for acoustic animal density studies, which may use SL to estimate probability of detection.
从 2012 年到 2017 年，人们在美国海军太平洋导弹靶场探测、定位和跟踪了小须鲸，并估计了动物声源级（SL）。通过将传输损耗估计值添加到 42159 个小须鲸叫声的测量接收水平中，得出了动物声源级（SL）。在夏威夷附近活动的小须鲸表现出了 Lombard 效应，即在背景噪声增加时，它们会提高叫声的强度。小须鲸还降低了在更高背景噪声水平下叫声 SL 的方差。尽管这些鲸鱼部分补偿了背景噪声的增加，但它们无法或不愿意将其 SL 增加到与背景噪声相同的水平。随着海洋变得更嘈杂，这种通讯空间的减少可能会对小须鲸种群的健康产生负面影响。本研究的结果对使用 SL 来估计检测概率的声学动物密度研究也具有重要意义。
