02178nas a2200217 4500008004100000022001400041245009300055210006900148260001600217520146300233100001601696700002101712700002401733700002701757700001601784700002601800700002601826700002001852700002601872856006201898 2019 eng d a0824-046900aSeasonal variation in Arctic marine mammal acoustic detection in the northern Bering Sea0 aSeasonal variation in Arctic marine mammal acoustic detection in cDec-12-20203 a

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.

1 aChou, Emily1 aAntunes, Ricardo1 aSardelis, Stephanie1 aStafford, Kathleen, M.1 aWest, Leigh1 aSpagnoli, Christopher1 aSouthall, Brandon, L.1 aRobards, Martin1 aRosenbaum, Howard, C. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/mms.1265801993nas a2200145 4500008004100000245011600041210006900157520145700226100002601683700002001709700002001729700002401749700002301773856005101796 2019 eng d00aHigh-amplitude vocalizations of male northern elephant seals and associated ambient noise on a breeding rookery0 aHighamplitude vocalizations of male northern elephant seals and 3 a

Northern elephant seals (Mirounga angustirostris) are massive, land-breeding marine mammals that produce loud, stereotyped calls during annual breeding seasons. To determine vocalization source levels emitted by competing males on a mainland breeding rookery, aerial calls were measured on-axis at 1 m from adult males using three different sound pressure level metrics. Time-averaged (1 min) ambient noise was also measured under variable environmental and social conditions. Results indicate that male northern elephant seals emit high amplitude airborne calls with little variation in call amplitude. Mean source levels ranged from 98 to 114 dB re: 20 μPa [root-mean-square (rms) -fast], 102–116 dB re: 20 μPa (rms-impulse), and 120–131 dB re: 20 μPa (peak) and average standard deviations for all metrics were <2.3 dB. Further, these seal rookeries exhibit high variability in ambient noise (in terms of both spectrum and amplitude) from biotic and environmental sources. Finally, males sampled did not adjust call amplitude to compensate for higher background noise levels and thus did not exhibit a Lombard effect. These findings reinforce the view that the remarkable vocalizations of male northern elephant seals serve as rigid and powerful signals that convey individual identity within noisy breeding colonies rather than as honest indicators of size, status, or motivation.

1 aSouthall, Brandon, L.1 aCasey, Caroline1 aHolt, Marla, M.1 aInsley, Stephen, J.1 aReichmuth, Colleen uhttp://asa.scitation.org/doi/10.1121/1.513942202268nas a2200277 4500008004100000245006700041210006600108490000600174520133800180653002701518653002601545653002401571653001501595653000901610100002001619700002301639700002501662700002101687700002601708700002301734700002301757700002601780700002701806700001901833856013801852 2018 eng d00aContext-dependent variability in blue whale acoustic behaviour0 aContextdependent variability in blue whale acoustic behaviour0 v53 a

Acoustic communication is an important aspect of reproductive, foraging and social behaviours for many marine species. Northeast Pacific blue whales (Balaenoptera musculus) produce three different call types—A, B and D calls. All may be produced as singular calls, but A and B calls also occur in phrases to form songs. To evaluate the behavioural context of singular call and phrase production in blue whales, the acoustic and dive profile data from tags deployed on individuals off southern California were assessed using generalized estimating equations. Only 22% of all deployments contained sounds attributed to the tagged animal. A larger proportion of tagged animals were female (47%) than male (13%), with 40% of unknown sex. Fifty per cent of tags deployed on males contained sounds attributed to the tagged whale, while only a few (5%) deployed on females did. Most calls were produced at shallow depths (less than 30 m). Repetitive phrasing (singing) and production of singular calls were most common during shallow, non-lunging dives, with the latter also common during surface behaviour. Higher sound production rates occurred during autumn than summer and they varied with time-of-day: singular call rates were higher at dawn and dusk, while phrase production rates were highest at dusk and night.

10aacoustic communication10aBalaenoptera musculus10abehavioural context10ablue whale10asong1 aLewis, Leah, A.1 aCalambokidis, John1 aStimpert, Alison, K.1 aFahlbusch, James1 aFriedlaender, Ari, S.1 aMcKenna, Megan, F.1 aMesnick, Sarah, L.1 aSouthall, Brandon, L.1 aSzesciorka, Angela, R.1 aŠirović, Ana uhttp://rsos.royalsocietypublishing.org/lookup/doi/10.1098/rsos.180241https://syndication.highwire.org/content/doi/10.1098/rsos.180241