Todd Nicole R E, Kavanagh Ailbhe S, Jessopp Mark J, Verboom Willem, Rogan Emer
MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland.
School of Biological, Earth & Environmental Sciences (BEES), University College Cork, Cork, Ireland.
PLoS One. 2025 Apr 9;20(4):e0320925. doi: 10.1371/journal.pone.0320925. eCollection 2025.
Passive acoustic monitoring (PAM) is a valuable tool for monitoring acoustically active small cetaceans such as the harbour porpoise (Phocoena phocoena), with a range of devices commonly used across studies. However, to ensure comparability of findings, there is a need to compare the ability of devices to detect acoustic signals. Using a playback approach, we determined the detection probability and effective detection radius/area (EDR/EDA) for co-deployed C-POD (Cetacean POrpoise Detectors), F-POD (Full waveform capture POD) and SoundTrap acoustic monitoring devices. We conducted playbacks of harbour porpoise recordings across two transects at a range of distances from moored devices, while accounting for a range of variables likely to influence the detection probability of playbacks. Distance from the devices influenced the detection probability across all devices, and a significant difference between transects was also found for the C-POD, possibly due to different ambient noise conditions. The maximum detection distance of the playbacks for the SoundTrap and the F-POD was between 400 - 500m, and EDR was estimated at 297m (EDA 0.276 km2) and 241m (EDA 0.181 km2), respectively. The maximum detection distance for the C-POD was lower, at 300 - 400m, and an EDR of 220m (EDA 0.153 km2). A lower EDR was calculated for harbour porpoise buzzes compared to clicks across devices, due to lower source level of buzzes, suggesting that time spent foraging may be underestimated in PAM studies. The results highlight how detection ranges may differ across commonly used PAM devices, affecting comparability of detection rates across studies. EDR/EDA is an important prerequisite for PAM-derived density and abundance estimates. As such, understanding how devices differ is essential for comparing studies and appropriate planning of long-term acoustic monitoring projects, particularly where estimates of abundance are a key goal.
被动声学监测（PAM）是监测如港湾鼠海豚（Phocoena phocoena）等发声小型鲸类动物的重要工具，在各项研究中通常会使用一系列设备。然而，为确保研究结果的可比性，有必要比较不同设备检测声学信号的能力。我们采用回放方法，确定了共同部署的C-POD（鲸类鼠海豚探测器）、F-POD（全波形捕获POD）和SoundTrap声学监测设备的检测概率以及有效检测半径/面积（EDR/EDA）。我们在距离系泊设备不同距离的两个断面进行了港湾鼠海豚录音的回放，同时考虑了一系列可能影响回放检测概率的变量。设备距离影响了所有设备的检测概率，并且C-POD在不同断面之间也存在显著差异，这可能是由于不同的环境噪声条件所致。SoundTrap和F-POD回放的最大检测距离在400 - 500米之间，估计EDR分别为297米（EDA 0.276平方千米）和241米（EDA 0.181平方千米）。C-POD的最大检测距离较低，为300 - 400米，EDR为220米（EDA 0.153平方千米）。与咔哒声相比，各设备对港湾鼠海豚嗡嗡声的EDR计算值较低，这是因为嗡嗡声的声源级较低，这表明在PAM研究中觅食时间可能被低估。结果突出了常用PAM设备的检测范围可能存在差异，这会影响不同研究间检测率的可比性。EDR/EDA是基于PAM得出密度和丰度估计值的重要前提条件。因此，了解设备之间的差异对于比较研究以及长期声学监测项目的合理规划至关重要，尤其是在丰度估计是关键目标的情况下。
