Identification and quantification of soundscape components in the Marginal Ice Zone

Abstract

Acoustic experiments using an integrated ice station were carried out during August 2012 and September 2013 in the Marginal Ice Zone (MIZ) of Fram Strait. The two experiments lasted four days each and collected under-ice acoustic recordings together with wave-in-ice and meteorological data. Synthetic aperture radar satellite data provided information on regional ice conditions. Four major components of the under-ice soundscape were identified: ship cavitation noise, seismic airgun noise, marine mammal vocalizations, and natural background noise. Ship cavitation noise was connected to heavy icebreaking. It dominated the soundscape at times, with noise levels (NLs) 100 km from the icebreaker increased by 10-28 dB. Seismic airgun noise that originated from seismic surveys more than 800 km away was present during 117 out of 188 observation hours. It increased NLs at 20-120 Hz by 2-6 dB. Marine mammal vocalizations were a minor influence on measured NLs, but their prevalence shows the biological importance of the MIZ. The 10th percentile of the noise distributions was used to identify the ambient background noise. Background NLs above 100 Hz differed by 12 dB between the two experiments, presumably due to variations in natural noise sources.

Marine mammal acoustic detections in the Greenland and Barents Sea, 2013 – 2014 seasons

“…Acoustic monitoring of the Arctic marine environment has been of increasing interest to the scientific community and management bodies 15 – 17 . The underwater soundscape, which is shaped by the traditionally measured physical acoustic signal and the dynamically changing acoustic environment, can be divided into natural (physical), biological and anthropogenic sources 18 .…”

Bearded seal (Erignathus barbatus) vocalizations across seasons and habitat types in Svalbard, Norway

“…In this study, the seasonal use of different types of trills was explored to attempt to gain insight into what call types might be most important in a mating context in varied ice environments. By increasing the duration and redundancy in their calling behaviour, bearded seal males likely increase the probability of reaching oestrus females and other males with their signals, despite their dispersed distribution in various types of sea ice environments, where signal to noise ratios tend to be low (Urick and Kuperman 1989;Geyer et al 2016). The long trill, which has been reported to be the most commonly used call type during the mating season in Svalbard, has a longer duration compared to step and sweep trills, especially in the low-frequency range, contributing to a better propagation of sound underwater (Van Parijs et al 2001;Risch et al 2007).…”

Effects of Geophony and Anthrophony on the Underwater Acoustic Environment in the East Siberian Sea, Arctic Ocean

“…The East Siberian Sea (ESS) is one of the least studied regions in the Arctic Ocean and there are many knowledge gaps regarding ambient noise around the East Siberian Shelf. Previous studies on underwater acoustic monitoring were conducted in the Bering Sea, Chukchi Sea, Beaufort Sea, Greenland Sea, and central Arctic Ocean (black circles in Figure 1a) (Chen et al., 2019; Geyer et al., 2016; Halliday et al., 2020; Heard et al., 2013; PAME, 2019; Southall et al., 2020; Wen et al., 2020). According to previous studies, the underwater acoustic environment in the Arctic Ocean is dependent on seasonal and geophysical conditions and is correlated with sea ice (PAME, 2019).…”