Kastelein Ronald A, Verboom Willem C, Jennings Nancy, de Haan Dick
Sea Mammal Research Company, Julianalaan 46, 3843 CC Harderwijk, The Netherlands.
J Acoust Soc Am. 2008 Apr;123(4):1858-61. doi: 10.1121/1.2874557.
The use of ultrasonic sounds in alarms for gillnets may be advantageous, but the deterring effects of ultrasound on porpoises are not well understood. Therefore a harbor porpoise in a large floating pen was subjected to a continuous 50 kHz pure tone with a source level of 122+/-3 dB (re 1 microPa, rms). When the test signal was switched on during test periods, the animal moved away from the sound source. Its respiration rate was similar to that during baseline periods, when the sound was switched off. The behavior of the porpoise was related to the sound pressure level distribution in the pen. The sound level at the animal's average swimming location during the test periods was approximately 107+/-3 dB (re 1 microPa, rms). The avoidance threshold sound pressure level for a continuous 50 kHz pure tone for this porpoise, in the context of this study, is estimated to be 108+/-3 dB (re 1 microPa, rms). This study demonstrates that porpoises may be deterred from an area by high frequency sounds that are not typically audible to fish and pinnipeds and would be less likely masked by ambient noise.
在刺网警报中使用超声波可能具有优势，但超声波对鼠海豚的威慑作用尚未得到充分了解。因此，将一只港湾鼠海豚置于一个大型浮动围栏中，使其暴露于源级为122±3分贝（相对于1微帕，均方根）的连续50千赫纯音环境中。在测试期间打开测试信号时，这只动物会远离声源。其呼吸频率与关闭声音的基线期相似。鼠海豚的行为与围栏内的声压级分布有关。测试期间，动物平均游泳位置的声级约为107±3分贝（相对于1微帕，均方根）。在本研究的背景下，这只鼠海豚对连续50千赫纯音的回避阈值声压级估计为108±3分贝（相对于1微帕，均方根）。这项研究表明，高频声音可能会使鼠海豚远离某个区域，而这些声音通常鱼类和鳍足类动物听不到，也不太可能被环境噪声掩盖。
