Erignathus Research Articles

My Wounded Island by J. Pasquet and M. Arbona

Pasquet, Jacques and Marion Arbona. My Wounded Island. Translated by Sophie B. Watson. Orca Books, 2017.Imarvaluk lives on a small island called Sarichef on the Chukchi Sea coast of Alaska. Imarvaluk tells the story of how her people live on their island, in their town of Shishmaref. She explains how they used to live in igloos but now live in small wooden homes. The men in her family still hunt bearded seal, walrus, elk, and caribou as their ancestors did. In the summers the family moves to a camp on the mainland by the Serpentine River where they hunt caribou, catch fish, and pick berries.Imarvaluk also tells of how their lives are changing because of the sea, and the monster within it. During winters long ago, the sea would freeze and protect the island from the waves. The ice would also enable her family to hunt. The creature in the sea has caused winter to retreat earlier and earlier, making the pack ice unstable to hunt on, and it slowly swallows the island into the sea. Imarvaluk describes how the home of her people will eventually disappear and how they may have to relocate to Nome, when her island becomes uninhabitable. Through her relationship with her grandfather, Imarvaluk explains how the culture of her people is very much at risk as they face the end of their island.This beautiful and emotionally packed story is remarkable in its ability to convey how environmental impacts are being felt by this Inupiat community. Illustrations by Marion Arbona use paint and texture to convey impactful images of life on Shishmaref, weaving the monster of the changing environment together with Inupiat mythology. It was refreshing to read a children’s book that takes up the very real changes caused by climate change, and in so doing, does not hesitate to leave the ending unresolved. This being said, My Wounded Island could evoke strong emotions and may be better read with an adult, so that there can be discussion about the issues it presents. This doesn’t mean parents should shy away from this book as it is truly a beautiful and impactful read for both young and old.Highly recommended: 4 out of 4 stars Reviewer: Hanne PearceHanne Pearce has worked at the University of Alberta Libraries since 2004. She holds a BA and MLIS and is currently working towards her Master of Arts in Communications and Technology. Her research interests include: visual communication, digital literacy, information literacy and the intersections between communication work and information work. She is also a freelance photographer and graphic designer.

ABUNDANCE AND DISTRIBUTION OF PHOCID SEALS ON ICE IN THE WESTERN BERING SEA IN SPRING, 2012–2013

Abundance and density distribution of four seal species (ringed, ribbon, spotted, and bearded) on spring ice was estimated based on the data from two instrumental aerial surveys in the western Bering Sea in April-May 2012 and April 2013 and compared with the previously published values. The number of ringed seals on ice was about 61,000, they were rather evenly distributed in the southern, middle and northern parts of the Russian EEZ in the Bering Sea. The estimated number of ribbon seals was about 62,000 in 2012, but only 15,000 in 2013. The number of bearded seals was estimated as 42,000 animals. The abundance and density distribution of spotted seals was shown to be a subject of significant interannual fluctuations with the maximum of about 97,000 individuals. The spotted or ribbon seals were not found in the Anadyr Bay, but importance of the Karaginsky Bay for reproduction of the phocid seals was confirmed. A large population of spotted seals was concentrated there and the ringed and bearded seals were presented there in the highest recorded density. Effectiveness of the instrumental aerial survey method application for assessing abundance and distribution of seals on sea ice was demonstrated. However, in order to estimate the real population abundance, it is essential to apply correction coefficients allowing to account for behavioural and migration processes predefining the proportion of seals available for detection.

The central role of Woods Hole Oceanographic Institution (WHOI) in marine mammal bioacoustics

WHOI researchers pioneered marine mammal bioacoustics. Schevill and Lawrence in 1949 made the first recordings of marine mammals, beluga whales, and in 1956 first demonstrated cetacean echolocation. Schevill later concentrated on the taxonomy and behavior of cetaceans while Watkins developed the first portable high-frequency recorder and passive and active acoustic tracking systems. Ray, Watkins, and Schevill in 1969 presented the first evidence of song in a marine mammal, the bearded seal, linked to the behavior of males in the breeding season. Watkins’ papers on vocalizations informed a generation of bioacousticians on how to interpret sonograms. He was one of the first to use the Navy’s SOSUS hydrophone array to track cetacean movements. Schevill and Watkins also inspired the research of others, both in recoding marine mammal sounds and in interpreting sound in behavior. Tyack led the development of the D-Tag, which simultaneously records vocalizations and movements of cetaceans. Ketten used CAT scans to develop hearing models for cetaceans. Sayigh advanced knowledge of delphnid signature whistles and Fristrup further developed the concept of soundscapes. Watkins and Schevill’s database of more than 20,000 vocalizations from 70 marine mammal species now resides at the New Bedford Whaling Museum, freely available to the public.WHOI researchers pioneered marine mammal bioacoustics. Schevill and Lawrence in 1949 made the first recordings of marine mammals, beluga whales, and in 1956 first demonstrated cetacean echolocation. Schevill later concentrated on the taxonomy and behavior of cetaceans while Watkins developed the first portable high-frequency recorder and passive and active acoustic tracking systems. Ray, Watkins, and Schevill in 1969 presented the first evidence of song in a marine mammal, the bearded seal, linked to the behavior of males in the breeding season. Watkins’ papers on vocalizations informed a generation of bioacousticians on how to interpret sonograms. He was one of the first to use the Navy’s SOSUS hydrophone array to track cetacean movements. Schevill and Watkins also inspired the research of others, both in recoding marine mammal sounds and in interpreting sound in behavior. Tyack led the development of the D-Tag, which simultaneously records vocalizations and movements of cetaceans. Ketten used CAT scans ...

Habitat selection and seasonal movements of young bearded seals (Erignathus barbatus) in the Bering Sea.

The first year of life is typically the most critical to a pinniped’s survival, especially for Arctic phocids which are weaned at only a few weeks of age and left to locate and capture prey on their own. Their seasonal movements and habitat selection are therefore important factors in their survival. During a cooperative effort between scientists and subsistence hunters in October 2004, 2005, and 2006, 13 female and 13 male young (i.e., age <2) bearded seals (Erignathus barbatus) were tagged with satellite-linked dive recorders (SDRs) in Kotzebue Sound, Alaska. Shortly after being released, most seals moved south with the advancing sea-ice through the Bering Strait and into the Bering Sea where they spent the winter and early spring. The SDRs of 17 (8 female and 9 male) seals provided frequent high-quality positions in the Bering Sea; their data were used in our analysis. To investigate habitat selection, we simulated 20 tracks per seal by randomly selecting from the pooled distributions of the absolute bearings and swim speeds of the tagged seals. For each point in the observed and simulated tracks, we obtained the depth, sea-ice concentration, and the distances to sea-ice, open water, the shelf break and coastline. Using logistic regression with a stepwise model selection procedure, we compared the simulated tracks to those of the tagged seals and obtained a model for describing habitat selection. The regression coefficients indicated that the bearded seals in our study selected locations near the ice edge. In contrast, aerial surveys of the bearded seal population, predominantly composed of adults, indicated higher abundances in areas farther north and in heavier pack ice. We hypothesize that this discrepancy is the result of behavioral differences related to age. Ice concentration was also shown to be a statistically significant variable in our model. All else being equal, areas of higher ice concentration are selected for up to about 80%. The effects of sex and bathymetry were not statistically significant. The close association of young bearded seals to the ice edge in the Bering Sea is important given the likely effects of climate warming on the extent of sea-ice and subsequent changes in ice edge habitat.

A multi-species synthesis of satellite telemetry data in the Pacific Arctic (1987–2015): Overlap of marine mammal distributions and core use areas

We collated available satellite telemetry data for six species of ice-associated marine mammals in the Pacific Arctic: ringed seals (Pusa hispida; n = 118), bearded seals (Erignathus barbatus, n = 51), spotted seals (Phoca largha, n = 72), Pacific walruses (Odobenus rosmarus divergens, n = 389); bowhead whales (Balaena mysticetus, n = 46), and five Arctic and sub-arctic stocks of beluga whales (Delphinapterus leucas, n = 103). We also included one seasonal resident, eastern North Pacific gray whales (Eschrichtius robustus, n = 12). This review summarized the distribution of daily locations from satellite-linked transmitters during two analysis periods, summer (May–November) and winter (December–April), and then examined the overlap among species. Six multi-species core use areas were identified during the summer period: 1) Chukotka/Bering Strait; 2) Norton Sound; 3) Kotzebue Sound; 4) the northeastern Chukchi Sea; 5) Mackenzie River Delta/Amundsen Gulf; and 6) Viscount Melville Sound. During the winter period, we identified four multi-species core use areas: 1) Anadyr Gulf/Strait; 2) central Bering Sea; 3) Nunivak Island; and 4) Bristol Bay. During the summer period, four of the six areas were centered on the greater Bering Strait region and the northwestern coast of Alaska and included most of the species we examined. The two remaining summer areas were in the western Canadian Arctic and were largely defined by the seasonal presence of Bering-Chukchi-Beaufort stock bowhead whales and Eastern Beaufort Sea stock beluga whales, whose distribution overlapped during both summer and winter periods. During the winter period, the main multi-species core use area was located near the Gulf of Anadyr and extended northwards through Anadyr and Bering Straits. This area is contained within the Bering Sea “green belt”, an area of enhanced primary and secondary productivity in the Bering Sea. We also described available telemetry data and where they can be found as of 2017. These data are important for understanding ice-associated marine mammal movements and habitat use in the Pacific Arctic and should be archived, with appropriate metadata, to ensure they are available for future retrospective analyses.

Seasonal Movements and Relative Abundance of Bearded Seals (&lt;i&gt;Erignathus barbatus&lt;/i&gt;) in the Coastal Waters of the Chukotka Peninsula

Information about bearded seal seasonal distribution in the Pacific Arctic is limited. Bearded seals (Erignathus barbatus Exleben, 1777) from coastal sites along the southern, eastern, and northern Chukotka Peninsula, Russian Federation, were observed most seasons during 1993 – 96, 1998 – 2000, 2002 – 05, and 2010 – 11. These observations provide spatial and temporal information about bearded seal seasonal distribution, movements, and relative numbers in the coastal zones. In winter, bearded seals aggregate on the young ice in the northern part of the Gulf of Anadyr. Numbers gradually increase during March. In springtime (April–May), bearded seals in the northern Gulf of Anadyr are relatively numerous around Nunligran (Cape Achen), but the number is highly variable across years. During spring bearded seals move eastward along the coast from the northern part of the Gulf of Anadyr towards the Bering Strait and then to the north, as the marginal ice edge zone retreats north. These movements to the east and north continue in ice-free water, and by August, the spring migration of bearded seals along the coast of the Chukotka Peninsula ends. In the summer months of August and September, few bearded seals are present in this coastal zone. The southward autumn migration of bearded seals is not evident near the coast, which suggests that it occurs farther from shore.

Underwater vocal complexity of Arctic seal Erignathus barbatus in Kongsfjorden (Svalbard).

In this study the description of underwater vocal repertoire of bearded seal in Svalbard (Norway) was extended. Two autonomous passive acoustic recorders were deployed for one year (August 2014-July 2015) in the inner and outer parts of the Kongsfjorden, and 1728 h were recorded and 17 220 vocalizations were found. Nine different vocalization classes were identified and characterized using ten acoustic parameters. The calls showed heterogeneous spectral features, but share the descending trend of frequency modulation. The different classes emerged were discriminated primarily by bandwidth and duration, and then by minimum frequency, central frequency, and maximum frequency in this order. This study represents a step forward to improve the understanding of the acoustic behaviour and the social function of these calls, and identified long passive acoustic monitoring as an effective method to assess vocal complexity and the ecology of marine species producing sounds.

Implications of ocean acidification in the Pacific Arctic: Experimental responses of three Arctic bivalves to decreased pH and food availability

Recent sea ice retreat and seawater warming in the Pacific Arctic are physical changes that are impacting arctic biological communities. Recently, ocean acidification from increases in anthropogenic CO2 has been identified as an additional stressor, particularly to calcifying organisms like bivalves. These bivalves are common prey items for benthivorous predators such as Pacific walruses (Odobenus rosmarus divergens), bearded seals (Erignathus barbatus), and diving seaducks, such as Spectacled Eiders (Somateria fischeri). We investigated the effects of decreased pH and food availability on growth (% change in length and wet weight and allometric growth characterizations) and oxygen consumption (mg/L/hour) of three common Arctic bivalves, Macoma calcarea, Astarte montagui, and Astarte borealis. Two sets of experiments were run for seven and eleven weeks, exposing the bivalves to control (8.05 ± 0.02 and 8.19 ± 0.003, respectively) and acidified (7.76 ± 0.01 and 7.86 ± 0.01, respectively) pH treatments. Length, weight, and oxygen consumption were not significantly different among the varying treatments after the seven-week exposure and only one significant effect of decreased pH and one significant effect of decreased food availability were observed after the end of the eleven-week exposure. Specifically, shells of A. borealis displayed a decrease in length in response to decreased pH and M. calcarea showed a decrease in length in response to limited food. The negative effects of pH observed in the experiments on growth and oxygen consumption were small, suggesting that at least two of these species are generally resilient to decreasing pH.

The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994.

Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (Pusa hispida), ribbon (Histriophoca fasciata), bearded (Erignathus barbatus) and spotted (Phoca largha) seal. Variations in catch per unit effort were explored in relation to year, sea ice conditions, day of the year, and geographic location. In most years, the harvest was predominantly represented by ringed seals (mean = 0.43, range 0.25–0.67), followed by ribbon (mean = 0.31, range 0.15–0.43), spotted (mean = 0.19, range 0.11–0.35) and bearded seals (mean = 0.07, range 0.03–0.14). The struck-and-lost percentages were as high as 30–35% for ringed, bearded and spotted seals and 15–20% for ribbon seals. Catch per unit effort (number of seals/skiff*day) for ringed, ribbon, and spotted seals had a similar seasonal pattern with a distinct spike in catches for spotted seals in the first week of May, for ribbon seals in the last week of May, and for ringed seals in the second week of June. Catches of bearded seals showed a less pronounced temporal structure with a gradual increase toward the end of the harvest season in the majority of years. Spatial distribution of harvest effort followed closely with seal distribution obtained from aerial surveys. These data could be used as a source of information on seal herd location throughout the breeding and molting seasons and for more complex demographic or life-table models. We did not find any evidence of the decline of catch per unit effort over the study period. Timely introduction of state regulations and efficient harvest management apparently prevented severe depletion of ice-associated seal populations in the Sea of Okhotsk during the periods of their intense exploitation.

Confronting preferential sampling when analysing population distributions: diagnosis and model‐based triage

SummaryPopulation surveys are often used to estimate the density, abundance, or distribution of natural populations. Recently, model‐based approaches to analyzing survey data have become popular because one can more readily accommodate departures from pre‐planned survey routes and construct more detailed maps than one can with design‐based procedures.Spatial models for population distributions (SMPDs) often make the implicit assumption that locations chosen for sampling and animal abundance at those locations are conditionally independent given modelled covariates. However, this assumption may be violated when survey effort is non‐randomized, leading to preferential sampling.We develop a hierarchical statistical modelling framework for detecting and alleviating the biasing effects of preferential sampling in spatial distribution models fitted to count data. The approach works by specifying a joint model for population density and the locations selected for sampling, and specifying a dependent correlation structure between the two processes.Using simulation, we show that moderate levels of preferential sampling can lead to large (e.g. 40%) bias in estimates of animal density and that our modelling approach can considerably reduce this bias. In contrast, preferential sampling did not appear to bias inferences about parameters informing species–habitat relationships (i.e. slope parameters).We apply our approach to aerial survey counts of bearded seals (Erignathus barbatus) in the eastern Bering Sea. As expected, models with a preferential sampling effect led to lower abundance than those without. However, several lines of reasoning (better predictive performance, higher biological realism) led us to prefer models without a preferential sampling effect for this dataset.When population surveys break from traditional scientific survey design principles, ecologists should recognize the potentially biasing effects of preferential sampling when estimating population density or occurrence. Joint models, such as those described in this paper, can be used to test and correct for such biases. However, such models can be unstable; ultimately the best way to avoid preferential sampling bias is to incorporate design‐based principles such as randomization and/or systematic sampling into survey design.

Incorporating Telemetry Error into Hidden Markov Models of Animal Movement Using Multiple Imputation

When data streams are observed without error and at regular time intervals, discrete-time hidden Markov models (HMMs) have become immensely popular for the analysis of animal location and auxiliary biotelemetry data. However, measurement error and temporally irregular data are often pervasive in telemetry studies, particularly in marine systems. While relatively small amounts of missing data that are missing-completely-at-random are not typically problematic in HMMs, temporal irregularity can result in few (if any) observations aligning with the regular time steps required by HMMs. Fitting HMMs that explicitly account for uncertainty attributable to location measurement error, temporally irregular observations, or other forms of missing data typically requires computationally demanding techniques, such as Markov chain Monte Carlo (MCMC). Using simulation and a real-world bearded seal (Erignathus barbatus) example, I investigate a practical alternative to incorporating measurement error and temporally irregular observations into HMMs based on multiple imputation of the position process drawn from a single-state continuous-time movement model. This two-stage approach is relatively simple, performed with existing software using efficient maximum likelihood methods, and completely parallelizable. I generally found the approach to perform well across a broad range of simulated measurement error and irregular sampling rates, with latent states and locations reliably recovered in nearly all simulated scenarios. However, high measurement error coupled with low sampling rates often induced bias in both the estimated probability distributions of data streams derived from the imputed position process and the estimated effects of spatial covariates on state transition probabilities. Results from the two-stage analysis of the bearded seal data were similar to a more computationally intensive single-stage MCMC analysis, but the two-stage analysis required much less computation time and no custom model-fitting algorithms. I thus found the two-stage multiple-imputation approach to be promising in terms of its ease of implementation, computation time, and performance. Code for implementing the approach using the R package “momentuHMM” is provided.Supplementary materials accompanying this paper appear online.

Resource partitioning between Pacific walruses and bearded seals in the Alaska Arctic and sub-Arctic.

Climate-mediated changes in the phenology of Arctic sea ice and primary production may alter benthic food webs that sustain populations of Pacific walruses (Odobenus rosmarus divergens) and bearded seals (Erignathus barbatus). Interspecific resource competition could place an additional strain on ice-associated marine mammals already facing loss of sea ice habitat. Using fatty acid (FA) profiles, FA trophic markers, and FA stable carbon isotope analyses, we found that walruses and bearded seals partitioned food resources in 2009-2011. Interspecific differences in FA profiles were largely driven by variation in non-methylene FAs, which are markers of benthic invertebrate prey taxa, indicating varying consumption of specific benthic prey. We used Bayesian multi-source FA stable isotope mixing models to estimate the proportional contributions of particulate organic matter (POM) from sympagic (ice algal), pelagic, and benthic sources to these apex predators. Proportional contributions of FAs to walruses and bearded seals from benthic POM sources were high [44 (17-67)% and 62 (38-83)%, respectively] relative to other sources of POM. Walruses also obtained considerable contributions of FAs from pelagic POM sources [51 (32-73)%]. Comparison of δ13C values of algal FAs from walruses and bearded seals to those from benthic prey from different feeding groups from the Chukchi and Bering seas revealed that different trophic pathways sustained walruses and bearded seals. Our findings suggest that (1) resource partitioning may mitigate interspecific competition, and (2) climate change impacts on Arctic food webs may elicit species-specific responses in these high trophic level consumers.

Distribution of populations of ringed seal Phoca hispida and bearded seal Erignathus barbatus in shallow and average-deep areas of the southwestern part of the Kara Sea in summer 2015.

In August-September 2015 in the southwest part of the Kara Sea, visual censuses of ringed seal (Phoca hispida) and bearded seal (Erignatus barbatus) from research vessels were carried out in the water area of 49 814 km2. For the first time, for calculation of abundance and density on ice-free area the SEAL-CALCULATION (TYULEN-RASCHET) software was used with application of separate extrapolation method by the selected sectors. Calculation for the whole census polygon yielded abundance of ringed seal of 4163 ± 16.9% and abundance of bearded seal of 1026 ± 28.4%. On the basis of the census results, a preliminary estimation of distribution of pinnipeds by various depths is presented.

Seasonal Trends in Acoustic Detection of Marine Mammals in Baffin Bay and Melville Bay, Northwest Greenland + Supplementary Appendix 1 (See Article Tools)

The expansion of hydrocarbon exploration in northwest Greenland has made it increasingly important to understand the occurrence of marine mammals in the region. We describe the seasonal occurrence of marine mammals and the spatial distribution of their calls in Baffin Bay and Melville Bay. Four Autonomous Multichannel Acoustic Recorders (AMARs) were deployed during summer 2012 (late July to early October), five recorders during September 2013, and two recorders from late September 2013 to early September 2014. The call presence of several species was analyzed using automatic call detection and manual verification analysis methods. A novel approach to discern narwhal (Monodon monoceros) clicks from beluga (Delphinapterus leucas) clicks was implemented during the verification process. Narwhal calls were detected in spring and fall, showing a south-to-north migration pattern in spring and a north-to-south migration pattern in fall. Few beluga whales were detected during fall 2013 and spring 2014. Bearded seal (Erignathus barbatus) calls were detected mainly during spring (mating period). A small number of bowhead whale calls (Balaena mysticetus) were detected during fall 2013 and spring and summer 2014. For the first time at this latitude in Baffin Bay, long-finned pilot whales (Globicephala melas) and sperm whales (Physeter macrocephalus) were detected during summer and fall. Our results suggest that the presence of marine mammals in Baffin Bay and Melville Bay is governed mainly by the annual cycle of sea ice formation and decay.

Bridging the gaps in animal movement: hidden behaviors and ecological relationships revealed by integrated data streams

AbstractInferences about animal behavior from movement models typically rely solely on location data, but auxiliary biotelemetry and environmental data are powerful and readily available resources for incorporating much more behavioral realism. Integrating multiple data streams can not only reveal hidden behaviors and ecological relationships that would otherwise be difficult or impossible to infer from location data alone, but also facilitate more realistic path reconstruction that respects important ecological features while bridging the information gaps that commonly arise due to measurement error or missing data. Using the bearded seal (Erignathus barbatus), a benthic predator associated with Arctic sea ice, we demonstrate how integrating location, dive activity, land cover, bathymetry, and sea ice data in a unified modeling framework allowed us to identify novel behavior states, such as hauling out on seasonal sea ice and those associated with competing foraging strategies (i.e., benthic vs. mid‐water prey). By utilizing multiple data streams, ecologists can move beyond conventional two‐state models (“foraging” and “transit”) and address more interesting hypotheses about activity budgets, resource selection, and many other areas of movement and behavioral ecology. The generality of our approach provides broad applicability to marine and terrestrial species, as well as many types of biotelemetry and environmental data.

Activity concentration measurements of selected radionuclides in seals from Canadian Arctic

The activity concentrations of naturally occurring radionuclides (such as 226Ra, 210Pb and 210Po) and long lived 137Cs were measured in a total of 119 tissue samples (43 blubber, 43 liver, and 33 muscle samples) from 40 ringed seals and 4 bearded seals collected in the Arviat area of Canada during the fall of 2014. Activity concentration of 210Po was measured in all seal liver and muscle samples individually. The average 210Po activity concentrations were 25 ± 7.6 Bq/kg fresh weight (fw) in muscle and 211 ± 58 Bq/kg fw in liver for ringed seals, and 20 ± 6.1 Bq/kg fw in muscle and 231 ± 150 Bq/kg fw in liver for bearded seals. Due to insufficient sample material for most samples collected, gamma counting for radioactive caesium and radiochemical analysis for 226Ra and 210Pb were performed for pooled samples. Activity concentrations of 210Pb and 226Ra were generally below detection limits. While 134Cs activity concentration was not detectable, 137Cs activity concentration was detected in muscle and liver samples. On average, the 137Cs activity concentrations were 0.25 ± 0.05 and 0.12 ± 0.04 Bq/kg fw in muscle and liver samples of ringed seals, and 0.11 ± 0.02 and 0.10 ± 0.03 Bq/kg fw in muscle and liver samples of bearded seals, respectively. Neither 210Po nor 137Cs were detected in the blubber samples. This study confirmed that 210Po is the dominant contributor to radiation doses resulting from seal consumption. Man-made contaminant 137Cs only contributes less than 0.01% of the total ingestion dose obtained from Arviat seals.

Inuit Symbolism of the Bearded Seal

The skins of the bearded seal—both dress and interior skins—were indispensable in Inuit/Yupiit technology. Converted into straps, thongs, covers, pokes, rain clothing, and underwear, the skins served to make transport possible, facilitate hunting activities, and protect people against wet and stormy weather. Similarly, the same skin objects permitted contact and exchanges with the beings of the Other Worlds, on which the earthly life of humans depended. Symbolic analysis of the characteristics of bearded seal as reflected in ritual, myth, and sayings reveals that bearded seal turns out to bear both frightening and beneficial meanings. Feared in the figure of a bogey at the height of winter, welcomed as the first seal to arrive from a great distance in early spring, inspiring reproduction and protecting Raven in renewing the earth at equinoxes, bearded seal made the Inuit/Yupiit world cohere.

Temporal complexity of southernBeaufortSea polar bear diets during a period of increasing land use

AbstractFrom 2000 to 2013, use of land as a seasonal habitat by polar bears (Ursus maritimus) of the southern Beaufort Sea (SB) subpopulation substantially increased. This onshore use has been linked to reduced spatial and temporal availability of sea ice, as well as to the availability of subsistence‐harvested bowhead whale (Balaena mysticetus) bone piles. Here, we evaluated the role of climate conditions on consumption of traditional ice‐associated prey relative to onshore bowhead whale bone piles. We determined seasonal and interannual trends in the diets ofSBpolar bears using fatty acid‐based analysis during this period of increasing land use. Diet estimates of 569SBpolar bears from 2004 to 2012 showed high seasonal fluctuations in the proportions of prey consumed. Higher proportions of bowhead whale, as well as ringed seal (Pusa hispida) and beluga whale (Delphinapterus leucas), were estimated to occur in the winter–spring diet, while higher proportions of bearded seal (Erignathus barbatus) were estimated for summer–fall diets. Trends in the annual mean proportions of individual prey items were not found in either period, except for significant declines in the proportion of beluga in spring‐sampled bears. Nonetheless, in years following a high winter Arctic oscillation index, proportions of ice‐associated ringed seal were lower in the winter–spring diets of adult females and juveniles. Proportions of bowhead increased in the winter–spring diets of adult males with the number of ice‐free days over the continental shelf. In one or both seasons, polar bears that were in better condition were estimated to have consumed less ringed seal and/or more bowhead whale than those in worse condition. Therefore, climate variation over this recent period appeared to influence the extent of onshore vs. on‐ice food use, which in turn, appeared to be linked to fluctuating condition ofSBpolar bears.

Seasonal marine mammal occurrence detected from passive acoustic monitoring in Scott Inlet, Nunavut, Canada

Monitoring Arctic wildlife is important due to the increasing potential impact of environmental and industrial changes. Passive acoustic monitoring (PAM) can be an important tool for wildlife management through observations of several species simultaneously along with abiotic elements such as industrial activity. Here, we use PAM methods to monitor the occurrence of marine mammals over an 8-month period (Oct 2012–May 2013) in Scott Inlet, Nunavut. When marine mammals were present, we investigated possible environmental correlates. Sea ice coverage strongly influenced detections of marine mammal sounds: narwhals and bowhead whales were only present before full ice cover occurred in the fall, while bearded seals and walruses could only be detected after ice formation. Tidal phase, time of the day, water temperature at 300 m depth, and air temperature all influenced detections of narwhal clicks. This PAM study provides a baseline measure for the presence of marine mammals over the fall to spring in Scott Inlet. Long-term PAM in the same location would allow us to document changes in the phenology of marine mammals at this site in relation to environmental changes.

The relationships between vocalizing bearded seals and sea ice extent in the southern Chukchi Sea

Bearded seal Erignathus barbatus is one of ice-obligate species, which breeds on seasonal sea-ice in the Arctic and sub-Arctic during March-May. They are threatened by the rapid changes in the Arctic environment due to recent climate change, which causes sea-ice reduction or transition of their prey biomass. To understand the seasonal distribution of bearded seals and assess the impacts of climate change, we deployed the underwater sound recorder at the Southern Chukchi Hotspot (SCH) (67.72oN, 168.83oW) during July 2012-October 2015. Calls of bearded seals were manually detected from September before sea-ice formation started, temporarily decreased during late-November-early-December when sea-ice were formed and increased again from January to the end of our recording periods (March 2013, May 2014 or June 2015) when the SCH were freezing. Combined with previous study, our results indicate that bearded seals come to the SCH from the northern part (i.e., Beaufort Sea) in September possibly to forage, and some move southerly to their breeding area (i.e., Bering Sea) coincident with sea-ice formation. These results suggest that seasonal distribution and vocal activity of bearded seals at the SCH, which are tied with sea-ice, might be changed by the Arctic sea-ice decline in the future.