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

Abstract

Declines in Arctic sea ice cover are influencing the distribution of protected endemic marine mammals, many of which are important for local Indigenous Peoples, and increasing the presence of potentially disruptive industrial activities. Due to increasing conservation concerns, we conducted the first year‐round acoustic monitoring of waters off Gambell and Savoonga (St. Lawrence Island, Alaska), and in the Bering Strait to quantify vocalizing presence of bowhead whales, belugas, walruses, bearded seals, and ribbon seals. Bottom‐mounted archival acoustic recorders collected data for up to 10 months per deployment between 2012 and 2016. Spectrograms were analyzed for species‐typical vocalizations, and daily detection rates and presence/absence were calculated. Generalized additive models were used to model call presence as a function of time‐of‐year, sea surface temperature, and sea ice concentration. We identified seasonality in call presence for all species, corroborating previous acoustic and distribution studies, and identified finer‐scale spatiotemporal distribution via occurrence of call presence between different monitoring sites. Time‐of‐year was the strongest significant effect on call presence for all species. These data provide important information on Arctic endemic species' spatiotemporal distributions in biologically and culturally important areas within a rapidly changing Arctic region.

Biologically Important Areas II for cetaceans within U.S. and adjacent waters – Aleutian Islands and Bering Sea Region

“…Three additional acoustic recorders had an ~10-20% duty cycle and 16-48 kHz sampling rate and were deployed in Bering Strait and near Gambell and Savoonga (Chou et al, 2019). The Bering Strait mooring was deployed from September 2012 to May 2013 and recorded bowhead whale calls from November to January and mid-March to April (Chou et al, 2019). The Gambell mooring was deployed from October 2014 to July 2016 and recorded bowhead whale detections from December to April (Chou et al, 2019).…”

“…The Bering Strait mooring was deployed from September 2012 to May 2013 and recorded bowhead whale calls from November to January and mid-March to April (Chou et al, 2019). The Gambell mooring was deployed from October 2014 to July 2016 and recorded bowhead whale detections from December to April (Chou et al, 2019). The Savoonga mooring was deployed from October 2014 to June 2015 and recorded bowhead whale detections from December to April (Chou et al, 2019).…”

“…The Gambell mooring was deployed from October 2014 to July 2016 and recorded bowhead whale detections from December to April (Chou et al, 2019). The Savoonga mooring was deployed from October 2014 to June 2015 and recorded bowhead whale detections from December to April (Chou et al, 2019).…”

“…Polygons in this F-BIA are based on the satellite tag 50% density contour from (Citta et al (2021), Fig. 4.4, January through April, 27-32 satellite tags were transmitting during January-April); St. Lawrence Island Indigenous knowledge (Noongwook et al, 2007;Oceana and Kawerak, Inc, 2014, the "Concentration" area); the Sireniki Chukotka shore station (Melnikov et al, 2004); a 37-km radius around acoustic moorings BS1, M8, and NM1 (based on an average detection range of 28-37 km per mooring), and a 20-km radius to the south of the Gambell mooring (Chou et al, 2019). The detection range for the Gambell mooring is reported as several tens of kilometers; we extended the radius around that mooring only 20 km south because bowhead whale direction from the mooring cannot be determined; additionally, from satellite tag data, we expected higher densities of bowhead whales to be north (not south) of the Gambell mooring in December.…”

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

“…Sea ice dynamics induced by environmental forcing could also be a source of sound from an infrasound frequency range from below 20 Hz to several kHz (Geyer et al., 2016; Glowacki et al., 2018; Kinda et al., 2015; Pettit et al., 2015). Marine species, including Arctic endemic marine mammals produce different types of vocalizations over a wide frequency range, which also contribute to the underwater acoustic signature of the Arctic Ocean (Chou et al., 2020; Halliday et al., 2017; Simard et al., 2014; Stafford et al., 2017). In this study, we provide the first assessment of the seasonal variability of ambient noise in the East Siberian Arctic Shelf, an acoustically pristine region on the planet.…”