Seasonal Patterns in Ocean Ambient Noise near Sachs Harbour, Northwest Territories + Supplementary Appendix 1 (See Article Tools)

Abstract

Ocean ambient noise is a crucial habitat feature for marine animals because it represents the lower threshold of their acoustically active space. Ambient noise is affected by noise from both natural sources, like wind and ice, and anthropogenic sources, such as shipping and seismic surveys. During the ice-covered season, ambient conditions in the Arctic are quieter than those in other regions because sea ice has a dampening effect. Arctic warming induced by climate change can raise noise levels by reducing sea ice coverage and increasing human activity, and these changes may negatively affect several species of marine mammals and other acoustically sensitive marine fauna. We document ambient noise off the west coast of Banks Island near Sachs Harbour, Northwest Territories, to provide baseline noise levels for the eastern Beaufort Sea. Noise levels were comparable to those found in other studies of the Canadian Arctic and Alaska and were typically much lower than levels reported farther south. Stronger wind increased noise, whereas greater ice concentration decreased it, dampening the effect of wind speed. Future work should expand monitoring to other locations in the Arctic, model the impact of increased human activities on ambient noise levels, and predict the impact of these changing levels on marine animals.

The summer soundscape of a shallow-water estuary used by beluga whales in the western Canadian Arctic

“…The dependency of SPL on both wind speed and wave height is well known (Wenz 1962) and has been found in other shallow water systems (Haxel et al 2013). Wind speed is often used in SPL analyses rather than wave height because wind speed is measured automatically by many weather stations, and is, therefore, easier to obtain (McDonald et al 2006;Roth et al 2012;Insley et al 2017).…”

“…Anthropophony will only influence the soundscape if noisy anthropogenic activities occur in that area (Gervaise et al 2012;Martin et al 2017). Although the relative contribution of the geophony will vary among soundscapes, noise from wind and waves will likely be a large contributor to the soundscape at all locations (Wenz 1962;Roth et al 2012;Insley et al 2017). The soundscape will also vary greatly between seasons as all three components vary differentially between seasons.…”

“…Throughout the Arctic, belugas have adapted to a complex soundscape. The Arctic is one of the quietest places on earth under solid sea ice (Diachok and Winokur 1974;Roth et al 2012;Insley et al 2017), but it can be extremely noisy when ice is forming and breaking up (Diachok and Winokur 1974;Roth et al 2012;Kinda et al 2013Kinda et al , 2015Insley et al 2017), during storm events (Roth et al 2012;Insley et al 2017), or around calving glaciers (Deane et al 2014). In contrast to other cetaceans that occur in temperate or tropical latitudes, belugas in the Arctic currently deal with very low levels of anthropogenic noise; however, climate change will likely result in a changing soundscape (Moore et al 2012).…”

Acoustic detections of Arctic marine mammals near Ulukhaktok, Northwest Territories, Canada

“…At this point, we are unsure of why bearded seals were more likely to be detected under high wind speed. Increased wind speed leads to higher ambient noise levels, even under solid ice conditions (Roth et al 2012;Insley et al 2017), which should make it more difficult to detect bearded seals. It is possible that bearded seals increase their source levels or calling rates during increased wind speed to compensate for increased ambient noise levels or, as per the diurnal pattern of calling rationale (Cleator et al 1989), they are simply more likely to be in the water during higher winds.…”

Seasonal variation in Arctic marine mammal acoustic detection in the northern Bering Sea

“…This is especially important in the Arctic. Given the relatively quiet natural baseline soundscape in the Arctic, marine mammal species endemic to the Arctic and sub‐Arctic regions may be more vulnerable to noise pollution impacts (Insley et al, ; Moore et al, ; Reeves et al, ). These include bowhead whales ( Balaena mysticetus ), beluga whales ( Delphinapterus leucas ), Pacific walruses ( Odobenus rosmarus divergens ), bearded seals ( Erignathus barbatus ), and ribbon seals ( Histriophoca fasciata ).…”