Diving is a critical behaviour of marine mammals, including belugas, which dive to forage and travel under Arctic sea ice. While the limitations of dive behaviour and physiological dive adaptations have been the focus of several studies, cellular adaptations, particularly those of the immune system, have been little considered. However, diving itself presents several challenges that can impact immune responses, leading to disease or injury. As beluga dive their behaviour changes in response to human activity or environmental shifts. It is necessary to better understand how the beluga’s immune system functions during diving. This review provides a brief overview of what is known about beluga’s diving behaviour and physiology and discusses the first efforts to understand the link between diving and health via immune function in belugas. This new area of research is an important consideration regarding potential sub-lethal impacts of a rapidly changing Arctic environment on beluga’s diving behaviour, health and disease susceptibility.
{"title":"The immune response and diving: conservation considerations for belugas (Delphinapterus leucas) in a changing Arctic environment","authors":"L. A. Thompson, T. Romano","doi":"10.33265/polar.v40.5499","DOIUrl":"https://doi.org/10.33265/polar.v40.5499","url":null,"abstract":"Diving is a critical behaviour of marine mammals, including belugas, which dive to forage and travel under Arctic sea ice. While the limitations of dive behaviour and physiological dive adaptations have been the focus of several studies, cellular adaptations, particularly those of the immune system, have been little considered. However, diving itself presents several challenges that can impact immune responses, leading to disease or injury. As beluga dive their behaviour changes in response to human activity or environmental shifts. It is necessary to better understand how the beluga’s immune system functions during diving. This review provides a brief overview of what is known about beluga’s diving behaviour and physiology and discusses the first efforts to understand the link between diving and health via immune function in belugas. This new area of research is an important consideration regarding potential sub-lethal impacts of a rapidly changing Arctic environment on beluga’s diving behaviour, health and disease susceptibility.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41263229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Billefjorden Fault Zone is a major terrane boundary in the Norwegian Arctic. The fault separates basement rocks of Svalbard’s north-eastern and north-western terranes that recorded discrete Precambrian tectonothermal histories and were accreted, intensely deformed and metamorphosed during the Caledonian Orogeny. Although the fault represents a major, crustal-scale tectonic boundary, its northward extent is not well constrained. The present short contribution addresses this issue and presents new seismic mapping of structures and rock units north of Wijdefjorden, where the Billefjorden Fault Zone may continue. This study shows that there is no evidence for major faulting of the top-basement reflection, and therefore, that the Billefjorden Fault Zone may die out within Wijdefjorden–Austfjorden, step ≥ 20 km laterally, or be invisible on the presented seismic data. Seismic data also suggest that Caledonian basement rocks in Ny-Friesland (north-eastern terrane) are not significantly different from basement rocks below the Devonian Graben in Andrée Land (north-western terrane). Potential implications include the absence of a major terrane boundary in northern Spitsbergen.
{"title":"The Billefjorden Fault Zone north of Spitsbergen: a major terrane boundary?","authors":"Jean-Baptiste P. Koehl, Lis Allaart","doi":"10.33265/polar.v40.7668","DOIUrl":"https://doi.org/10.33265/polar.v40.7668","url":null,"abstract":"The Billefjorden Fault Zone is a major terrane boundary in the Norwegian Arctic. The fault separates basement rocks of Svalbard’s north-eastern and north-western terranes that recorded discrete Precambrian tectonothermal histories and were accreted, intensely deformed and metamorphosed during the Caledonian Orogeny. Although the fault represents a major, crustal-scale tectonic boundary, its northward extent is not well constrained. The present short contribution addresses this issue and presents new seismic mapping of structures and rock units north of Wijdefjorden, where the Billefjorden Fault Zone may continue. This study shows that there is no evidence for major faulting of the top-basement reflection, and therefore, that the Billefjorden Fault Zone may die out within Wijdefjorden–Austfjorden, step ≥ 20 km laterally, or be invisible on the presented seismic data. Seismic data also suggest that Caledonian basement rocks in Ny-Friesland (north-eastern terrane) are not significantly different from basement rocks below the Devonian Graben in Andrée Land (north-western terrane). Potential implications include the absence of a major terrane boundary in northern Spitsbergen.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47851362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Kovacs, J. Citta, T. Brown, R. Dietz, S. Ferguson, L. Harwood, M. Houde, E. V. Lea, L. Quakenbush, F. Rigét, A. Rosing-Asvid, T. G. Smith, Vladimir Svetochev, O. Svetocheva, C. Lydersen
The ringed seal is a small phocid seal that has a northern circumpolar distribution. It has long been recognized that body size is variable in ringed seals, and it has been suggested that ecotypes that differ in size exist. This study explores patterns of body size (length and girth) and age-at-maturity across most of the Arctic subspecies’ range using morphometric data from 35 sites. Asymptotic lengths varied from 113 to 151 cm, with sites falling into five distinct size clusters (for each sex). Age-at-maturity ranged from 3.1 to 7.4 years, with sites that had early ages of sexual maturity generally having small length-at-maturity and small final body length. The sexes differed in length at some sites, but not in a consistent pattern of dimorphism. The largest ringed seals occurred in western Greenland and eastern Canada, and the smallest occurred in Alaska and the White Sea. Latitudinal trends occurred only within sites in the eastern Canadian Arctic. Girth (with length and season accounted for) was also highly variable but showed no notable spatial pattern; males tended to be more rotund than females. Genetic studies are needed, starting with the “giants” at Kangia (Greenland) and in northern Canada to determine whether they are genetically distinct ecotypes. Additional research is also needed to understand the ecological linkages that drive the significant regional size differences in ringed seals that were confirmed in this study, and also to understand their implications with respect to potential adaptation to climate change.
{"title":"Variation in body size of ringed seals (Pusa hispida hispida) across the circumpolar Arctic: evidence of morphs, ecotypes or simply extreme plasticity?","authors":"K. Kovacs, J. Citta, T. Brown, R. Dietz, S. Ferguson, L. Harwood, M. Houde, E. V. Lea, L. Quakenbush, F. Rigét, A. Rosing-Asvid, T. G. Smith, Vladimir Svetochev, O. Svetocheva, C. Lydersen","doi":"10.33265/polar.v40.5753","DOIUrl":"https://doi.org/10.33265/polar.v40.5753","url":null,"abstract":"The ringed seal is a small phocid seal that has a northern circumpolar distribution. It has long been recognized that body size is variable in ringed seals, and it has been suggested that ecotypes that differ in size exist. This study explores patterns of body size (length and girth) and age-at-maturity across most of the Arctic subspecies’ range using morphometric data from 35 sites. Asymptotic lengths varied from 113 to 151 cm, with sites falling into five distinct size clusters (for each sex). Age-at-maturity ranged from 3.1 to 7.4 years, with sites that had early ages of sexual maturity generally having small length-at-maturity and small final body length. The sexes differed in length at some sites, but not in a consistent pattern of dimorphism. The largest ringed seals occurred in western Greenland and eastern Canada, and the smallest occurred in Alaska and the White Sea. Latitudinal trends occurred only within sites in the eastern Canadian Arctic. Girth (with length and season accounted for) was also highly variable but showed no notable spatial pattern; males tended to be more rotund than females. Genetic studies are needed, starting with the “giants” at Kangia (Greenland) and in northern Canada to determine whether they are genetically distinct ecotypes. Additional research is also needed to understand the ecological linkages that drive the significant regional size differences in ringed seals that were confirmed in this study, and also to understand their implications with respect to potential adaptation to climate change.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48828371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The beluga (Dephinapterus leucas) has a discontinuous circumpolar distribution in the Arctic and Subarctic regions, with eight populations occurring in Canadian waters (Stewart & Stewart 1989; COSEWIC 2016). The lack of a dorsal fin and a relatively thick dermis (5–12 mm) make the species particularly well adapted to environments with seasonal and extensive ice cover. The population in the SLE, Canada, is at the southern limit of the species’ global distribution and probably established itself thereafter the Wisconsin glaciation (Harington 1977, 2008). The beluga persistence in the SLE is probably largely due to the combination of an extensive and seasonal seaice cover and the cold and productive environmental conditions that are maintained in this region in part from the influx and upwelling of Arctic waters of the Labrador Current (El-Sabh & Silverberg 1990). The SLE beluga, like several other populations, undertakes seasonal movements, but its extent appears limited to a few tens or hundreds of kilometres (Mosnier et al. 2010). The core of its distribution remains in the SLE year-round, but an unknown and likely variable proportion of the population moves eastward each fall to winter in the western Gulf of St. Lawrence (Fig. 1). While immigration from other populations might have been notable a century ago (Vladykov 1944), the SLE beluga population now has the lowest haplotype diversity of all beluga populations and shares none with other populations (Postma 2017; Skovring et al. 2019). Abstract
白鲸(Dephinapterus leucas)在北极和亚北极地区有不连续的环极分布，在加拿大水域有8个种群(Stewart & Stewart 1989;COSEWIC 2016)中。缺乏背鳍和相对较厚的真皮(5-12毫米)使该物种特别适应季节性和广泛冰盖的环境。加拿大SLE的种群处于该物种全球分布的南部极限，可能是在威斯康辛冰期之后建立起来的(Harington 1977,2008)。白鲸在SLE的持续存在可能主要是由于广泛的季节性海冰覆盖和该地区维持的寒冷和多产的环境条件的结合，部分原因是拉布拉多洋流的北极水域的涌入和上涌(El-Sabh & Silverberg 1990)。SLE白鲸和其他几个种群一样，也会进行季节性迁徙，但其范围似乎仅限于几十或几百公里(Mosnier et al. 2010)。其分布的核心全年仍在SLE，但每年秋冬，在圣劳伦斯湾西部，未知且可能可变的种群比例向东移动(图1)。尽管一个世纪前其他种群的移民可能很明显(Vladykov 1944)， SLE白鲸种群现在的单倍型多样性是所有白鲸种群中最低的，与其他种群没有任何共享(Postma 2017;Skovring et al. 2019)。摘要
{"title":"The challenges of a small population exposed to multiple anthropogenic stressors and a changing climate: the St. Lawrence Estuary beluga","authors":"V. Lesage","doi":"10.33265/polar.v40.5523","DOIUrl":"https://doi.org/10.33265/polar.v40.5523","url":null,"abstract":"The beluga (Dephinapterus leucas) has a discontinuous circumpolar distribution in the Arctic and Subarctic regions, with eight populations occurring in Canadian waters (Stewart & Stewart 1989; COSEWIC 2016). The lack of a dorsal fin and a relatively thick dermis (5–12 mm) make the species particularly well adapted to environments with seasonal and extensive ice cover. The population in the SLE, Canada, is at the southern limit of the species’ global distribution and probably established itself thereafter the Wisconsin glaciation (Harington 1977, 2008). The beluga persistence in the SLE is probably largely due to the combination of an extensive and seasonal seaice cover and the cold and productive environmental conditions that are maintained in this region in part from the influx and upwelling of Arctic waters of the Labrador Current (El-Sabh & Silverberg 1990). The SLE beluga, like several other populations, undertakes seasonal movements, but its extent appears limited to a few tens or hundreds of kilometres (Mosnier et al. 2010). The core of its distribution remains in the SLE year-round, but an unknown and likely variable proportion of the population moves eastward each fall to winter in the western Gulf of St. Lawrence (Fig. 1). While immigration from other populations might have been notable a century ago (Vladykov 1944), the SLE beluga population now has the lowest haplotype diversity of all beluga populations and shares none with other populations (Postma 2017; Skovring et al. 2019). Abstract","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49028876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Justin T. Richard, Rachael Levine, T. Romano, B. Sartini
Simultaneous observations of reproductive physiology and behaviour were conducted on a group of two male and two female belugas under professionally managed care for one year to explore potential mating strategies. Weekly blow sampling for progesterone in females was used to define the breeding season by detecting three oestrous cycles in one female. Twice weekly blow sampling for testosterone and twice monthly testes measurements via ultrasonography were used to detect reproductive seasonality in both males. Female–male association frequency varied longitudinally, with 70% of all interactions occurring during the 16-week breeding season. Male–male associations did not vary seasonally. Male display behaviours towards the female occurred 14.8 times more frequently during the breeding season (0.164 ± 0.188 behaviours/min) than outside of the breeding season (0.011 ± 0.042 behaviours/min). The cycling female responded variably to male display behaviours by altering swim speed or body orientation towards the male. Although this small sample size limits broad conclusions, the frequent display behaviours, low copulation rate and lack of serious male–male aggression are consistent with predictions for pre-copulatory female mate choice developed from the current knowledge of beluga reproductive physiology. These observations, which are not feasible for wild belugas, provide important management considerations because reduced opportunities for mate choice could limit the reproductive rate, especially in small populations.
{"title":"Minimally invasive physiological correlates of social behaviour in belugas (Delphinapterus leucas) under human care","authors":"Justin T. Richard, Rachael Levine, T. Romano, B. Sartini","doi":"10.33265/polar.v40.5504","DOIUrl":"https://doi.org/10.33265/polar.v40.5504","url":null,"abstract":"Simultaneous observations of reproductive physiology and behaviour were conducted on a group of two male and two female belugas under professionally managed care for one year to explore potential mating strategies. Weekly blow sampling for progesterone in females was used to define the breeding season by detecting three oestrous cycles in one female. Twice weekly blow sampling for testosterone and twice monthly testes measurements via ultrasonography were used to detect reproductive seasonality in both males. Female–male association frequency varied longitudinally, with 70% of all interactions occurring during the 16-week breeding season. Male–male associations did not vary seasonally. Male display behaviours towards the female occurred 14.8 times more frequently during the breeding season (0.164 ± 0.188 behaviours/min) than outside of the breeding season (0.011 ± 0.042 behaviours/min). The cycling female responded variably to male display behaviours by altering swim speed or body orientation towards the male. Although this small sample size limits broad conclusions, the frequent display behaviours, low copulation rate and lack of serious male–male aggression are consistent with predictions for pre-copulatory female mate choice developed from the current knowledge of beluga reproductive physiology. These observations, which are not feasible for wild belugas, provide important management considerations because reduced opportunities for mate choice could limit the reproductive rate, especially in small populations.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48135292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Behavioural observations of captive beluga whales have complemented and extended much of what has been learnt about this species in the wild. Aquarium-based research has provided finer-scale specificity for many topics, including the seasonal breeding pattern that is characteristic of this species, as well as socio-sexual behaviour that appears to be an important part of the behavioural repertoire of this species. One example is a strong propensity for male–male social interactions that begin to develop at an early age. In addition, detailed behavioural milestones in calves have been documented in ways that extend that which have been collected from wild populations. These include swim positions with mother, separations/reunions with mother, and other social interactions, and play. Characteristics of beluga maternal care have also been studied more often in captive settings than in the wild, particularly with respect to details pertaining to nursing behaviour, individual differences in maternal style and allomaternal care. Other topics that have received scientific scrutiny in zoological settings include individual differences and behavioural laterality. Thus, a greater understanding of beluga behavioural biology has the potential to emerge as a consequence of synergy between research conducted in the two settings.
{"title":"Synergy between behavioural research on beluga whales (Delphinapterus leucas) conducted in zoological and wild settings","authors":"H. Hill, Deirdre B. Yeater, M. Noonan","doi":"10.33265/POLAR.V40.5508","DOIUrl":"https://doi.org/10.33265/POLAR.V40.5508","url":null,"abstract":"Behavioural observations of captive beluga whales have complemented and extended much of what has been learnt about this species in the wild. Aquarium-based research has provided finer-scale specificity for many topics, including the seasonal breeding pattern that is characteristic of this species, as well as socio-sexual behaviour that appears to be an important part of the behavioural repertoire of this species. One example is a strong propensity for male–male social interactions that begin to develop at an early age. In addition, detailed behavioural milestones in calves have been documented in ways that extend that which have been collected from wild populations. These include swim positions with mother, separations/reunions with mother, and other social interactions, and play. Characteristics of beluga maternal care have also been studied more often in captive settings than in the wild, particularly with respect to details pertaining to nursing behaviour, individual differences in maternal style and allomaternal care. Other topics that have received scientific scrutiny in zoological settings include individual differences and behavioural laterality. Thus, a greater understanding of beluga behavioural biology has the potential to emerge as a consequence of synergy between research conducted in the two settings.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47622955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Long-term meteorological data for the Arctic are sparse. One of the longest quasi-continuous temperature time series in the High Arctic is the extended Svalbard Airport series, providing daily temperature data from 1898 until the present. Here, I derive an adjustment to historic temperature observations on the island of Nordaustlandet, north-east Svalbard, in order to link these to the extended Svalbard Airport series. This includes the Haudegen observations at Rijpfjorden during 1944/45 and a previously unrecognized data set obtained by the Norwegian hunters and trappers Gunnar Knoph and Henry Rudi during their wintering at Rijpfjorden in 1934/35. The adjustment is based on data from an automatic weather station at Rijpfjorden during 2014–16 and verified with other independent historic temperature observations on Nordaustlandet. An analysis of the Haudegen radiosonde data indicates that the surface temperature observations at Rijpfjorden are generally well correlated with the free tropospheric temperatures at 850 hPa, but occasionally show the occurrence of boundary-layer inversions during winter, where local temperatures fall substantially below what is expected from the regression. The adjusted historic observations from Nordaustlandet can, therefore, be used to fill remaining gaps in the extended Svalbard Airport series.
{"title":"Historic temperature observations on Nordaustlandet, north-east Svalbard","authors":"B. Sinnhuber","doi":"10.33265/POLAR.V40.7564","DOIUrl":"https://doi.org/10.33265/POLAR.V40.7564","url":null,"abstract":"Long-term meteorological data for the Arctic are sparse. One of the longest quasi-continuous temperature time series in the High Arctic is the extended Svalbard Airport series, providing daily temperature data from 1898 until the present. Here, I derive an adjustment to historic temperature observations on the island of Nordaustlandet, north-east Svalbard, in order to link these to the extended Svalbard Airport series. This includes the Haudegen observations at Rijpfjorden during 1944/45 and a previously unrecognized data set obtained by the Norwegian hunters and trappers Gunnar Knoph and Henry Rudi during their wintering at Rijpfjorden in 1934/35. The adjustment is based on data from an automatic weather station at Rijpfjorden during 2014–16 and verified with other independent historic temperature observations on Nordaustlandet. An analysis of the Haudegen radiosonde data indicates that the surface temperature observations at Rijpfjorden are generally well correlated with the free tropospheric temperatures at 850 hPa, but occasionally show the occurrence of boundary-layer inversions during winter, where local temperatures fall substantially below what is expected from the regression. The adjusted historic observations from Nordaustlandet can, therefore, be used to fill remaining gaps in the extended Svalbard Airport series.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2021-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47686272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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