Goldbogen J A, Stimpert A K, DeRuiter S L, Calambokidis J, Friedlaender A S, Schorr G S, Moretti D J, Tyack P L, Southall B L
Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA Department of Oceanography, Naval Postgraduate School, Monterey, CA 93943, USA
J Exp Biol. 2014 Jul 15;217(Pt 14):2449-55. doi: 10.1242/jeb.103259. Epub 2014 May 6.
Low-frequency acoustic signals generated by baleen whales can propagate over vast distances, making the assignment of calls to specific individuals problematic. Here, we report the novel use of acoustic recording tags equipped with high-resolution accelerometers to detect vibrations from the surface of two tagged fin whales that directly match the timing of recorded acoustic signals. A tag deployed on a buoy in the vicinity of calling fin whales and a recording from a tag that had just fallen off a whale were able to detect calls acoustically but did not record corresponding accelerometer signals that were measured on calling individuals. Across the hundreds of calls measured on two tagged fin whales, the accelerometer response was generally anisotropic across all three axes, appeared to depend on tag placement and increased with the level of received sound. These data demonstrate that high-sample rate accelerometry can provide important insights into the acoustic behavior of baleen whales that communicate at low frequencies. This method helps identify vocalizing whales, which in turn enables the quantification of call rates, a fundamental component of models used to estimate baleen whale abundance and distribution from passive acoustic monitoring.
须鲸产生的低频声学信号能够在广阔的距离上传播，这使得将叫声归属于特定个体变得困难。在此，我们报告了一种新颖的方法，即使用配备高分辨率加速度计的声学记录标签来检测两只佩戴标签的长须鲸体表的振动，这些振动与记录的声学信号的时间直接匹配。部署在正在呼叫的长须鲸附近浮标上的标签以及刚从鲸鱼身上掉落的标签所记录的数据，能够通过声学方式检测到叫声，但并未记录到在呼叫个体上测量到的相应加速度计信号。在两只佩戴标签的长须鲸上测量的数百次叫声中，加速度计在所有三个轴上的响应通常是各向异性的，似乎取决于标签的放置位置，并且会随着接收到的声音强度增加而增强。这些数据表明，高采样率加速度测量能够为低频交流的须鲸的声学行为提供重要见解。这种方法有助于识别发声的鲸鱼，进而能够对叫声频率进行量化，而叫声频率是用于通过被动声学监测来估计须鲸数量和分布的模型的一个基本组成部分。
