Comparing the performance of C-PODs and SoundTrap/PAMGUARD in detecting the acoustic activity of harbor porpoises (Phocoena phocoena).

• Published in: Proceedings of Meetings on Acoustics,
• Main Authors: Sarnocinska, Joanna, Tougaard, Jakob, Johnson, Mark, Madsen, Peter T., Wahlberg, Magnus
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: Phocoena phocoena
• Online Access: https://portal.findresearcher.sdu.dk/da/publications/c91ecc25-2eef-4b17-a0d7-f53504f09528; https://doi.org/10.1121/2.0000288; https://findresearcher.sdu.dk/ws/files/121740810/Comparing_the_performance_of_C_PODs.pdf

The C-POD logger is a widely used instrument for passive acoustic monitoring of harbor porpoises, but the absence of a continuous recording in this device makes it difficult to verify its performance. An alternative but more labor-intensive approach is to use a wideband sound recorder and off-line detection software. Here we compare the performance of the C-POD with that of a HF SoundTrap recorder analysed with PAMGUARD software. Seven deployments were made with C-PODs and SoundTraps in the Danish Great and Little Belts between June and November, 2015. There was a positive but generally poor correlation between PAMGUARD and C-POD detections, with the C-PODs detecting only about 21-94% of the click trains detected by PAMGUARD based on the broadband recordings. The main explanation behind this poor correspondence is likely that PAMGUARD performs classification on single clicks, whereas the C-POD classifies groups of clicks ('trains') collectively. Such poor correlation between two common methods can have severe implications for conclusions reached in effect and abundance studies.