Vessel noise exposures of harbour seals from the Wadden Sea ...

• Main Authors: Nachtsheim, Dominik A., Johnson, Mark, Schaffeld, Tobias, Van Neer, Abbo, Madsen, Peter T., Findlay, Charlotte R., Rojano-Doñate, Laia, Teilmann, Jonas, Mikkelsen, Lonnie, Baltzer, Johannes, Ruser, Andreas, Siebert, Ursula, Schnitzler, Joseph G.
• Format: Dataset
• Language: English
• Published: Dryad 2023
• Subjects: FOS Natural sciences; Harbour seal; DTAG; Phoca vitulina; vessel exposure rates; AIS; North Sea; long-duration acoustic dataloggers; underwater noise; harbour seal
• Online Access: https://dx.doi.org/10.5061/dryad.mkkwh714m; https://datadryad.org/stash/dataset/doi:10.5061/dryad.mkkwh714m

The North Sea faces intense ship traffic owing to increasing human activities at sea. As harbour seals (Phoca vitulina) are abundant top predators in the North Sea, it is hypothesised that they experience repeated, high-amplitude vessel exposures. Here, we test this hypothesis by quantifying vessel noise exposures from deployments of long-term sound and movement tags (DTAGs) on nine harbour seals from the Wadden Sea. An automated tool was developed to detect intervals of elevated noise in the sound recordings. An assessment by multiple raters was performed to classify the source as either vessels or other sounds. A total of 133 vessel passes were identified with received levels >97 dB re 1µPa RMS in the 2 kHz decidecade band and with ambient noise >6 dB below this detection threshold. Tagged seals spent most of their time within Marine Protected Areas (89 ± 13%, mean ± SD) and were exposed to high-amplitude vessel passes 4.3 ± 1.6 times per day. Only 32% of vessel passes were plausibly associated with ...