F. Ercan, D. Blok, S. Weijers, Astrid Odé, F. Wagner-Cremer
The North Atlantic Oscillation (NAO) determines wind speed and direction, seasonal heat, moisture transport, storm tracks, cloudiness and sea-ice cover through atmospheric mass balance shifts between the Arctic and the subtropical Atlantic. The NAO is characterized by the typical, yet insufficiently understood, seesaw pattern of warmer winter and spring temperatures over Scandinavia and cooler temperatures over Greenland during the positive phase of the NAO, and vice versa during the negative phase. We tested the potential to reconstruct NAO variation beyond the meteorological record through the application of a microphenological proxy. We measured the Undulation Index (UI) in Betula nana epidermal cells from herbarium leaf samples and fossil peat fragments dating back to 1865—exceeding most meteorological records in the Arctic—to estimate imprints of spring thermal properties and NAO in Greenland and Finland. We found negative relations between Greenland UI and late winter, spring and early summer NAO, and mostly positive, but not significant, relations between Finland UI and NAO in years with pronounced NAO expression. The direction of the UI response in this common circumpolar species is, therefore, likely in line with the NAO seesaw effect, with leaf development response to NAO fluctuations in northern Europe opposing the response in Greenland and vice versa. Increased knowledge of the UI response to climate may contribute to understanding ecological properties of key Arctic species, whilst additionally providing a proxy for NAO dynamics.
{"title":"North Atlantic Oscillation seesaw effect in leaf morphological records from dwarf birch shrubs in Greenland and Finland","authors":"F. Ercan, D. Blok, S. Weijers, Astrid Odé, F. Wagner-Cremer","doi":"10.33265/polar.v40.7709","DOIUrl":"https://doi.org/10.33265/polar.v40.7709","url":null,"abstract":"The North Atlantic Oscillation (NAO) determines wind speed and direction, seasonal heat, moisture transport, storm tracks, cloudiness and sea-ice cover through atmospheric mass balance shifts between the Arctic and the subtropical Atlantic. The NAO is characterized by the typical, yet insufficiently understood, seesaw pattern of warmer winter and spring temperatures over Scandinavia and cooler temperatures over Greenland during the positive phase of the NAO, and vice versa during the negative phase. We tested the potential to reconstruct NAO variation beyond the meteorological record through the application of a microphenological proxy. We measured the Undulation Index (UI) in Betula nana epidermal cells from herbarium leaf samples and fossil peat fragments dating back to 1865—exceeding most meteorological records in the Arctic—to estimate imprints of spring thermal properties and NAO in Greenland and Finland. We found negative relations between Greenland UI and late winter, spring and early summer NAO, and mostly positive, but not significant, relations between Finland UI and NAO in years with pronounced NAO expression. The direction of the UI response in this common circumpolar species is, therefore, likely in line with the NAO seesaw effect, with leaf development response to NAO fluctuations in northern Europe opposing the response in Greenland and vice versa. Increased knowledge of the UI response to climate may contribute to understanding ecological properties of key Arctic species, whilst additionally providing a proxy for NAO dynamics.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44033256","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}
G. O’Corry-Crowe, Tatiana Ferrer, J. Citta, R. Suydam, L. Quakenbush, J. Burns, J. Monroy, A. Whiting, G. Seaman, Willie Goodwin, Sr., M. Meyer, Sarah L. Rodgers, K. Frost
We investigate the recent history and stock identity of beluga whales (Delphinapterus leucas) in Kotzebue Sound in the Chukchi Sea, a region long frequented by large numbers of belugas in summer until their near disappearance in the 1980s. Wide variation in numbers since then suggests a complex recent history that hinders recovery efforts. Analysis of teeth sampled during the historical (pre-decline) era using ancient DNA (aDNA) methods found that the original Kotzebue Sound whales were differentiated for mitochondrial DNA (mtDNA) from other summering concentrations across the Pacific Arctic revealing a demographically distinct subpopulation where long-established migratory culture likely facilitated population divergence. Analysis of microsatellite (nDNA) and mtDNA markers in belugas from the contemporary (post-decline) era revealed that whales from other stocks likely visited Kotzebue Sound, including during two low ice years when relatively large numbers of whales were present. Some mtDNA lineages were found only in Kotzebue Sound, with one recorded in both the historical and contemporary eras. Exclusion tests found a number of whales in Kotzebue Sound during the contemporary era that had nDNA genotypes unlikely to arise in other contemporary stocks in the Pacific Arctic. Our findings indicate that the Kotzebue Sound belugas comprised a unique stock of which a few remnants likely still co-occur with belugas from other larger stocks. We recommend that the US government work through the co-management process to greatly reduce or eliminate the taking of belugas, especially adult females, likely to belong to the Kotzebue Sound stock, until they recover.
{"title":"Genetic history and stock identity of beluga whales in Kotzebue Sound","authors":"G. O’Corry-Crowe, Tatiana Ferrer, J. Citta, R. Suydam, L. Quakenbush, J. Burns, J. Monroy, A. Whiting, G. Seaman, Willie Goodwin, Sr., M. Meyer, Sarah L. Rodgers, K. Frost","doi":"10.33265/polar.v40.7623","DOIUrl":"https://doi.org/10.33265/polar.v40.7623","url":null,"abstract":"We investigate the recent history and stock identity of beluga whales (Delphinapterus leucas) in Kotzebue Sound in the Chukchi Sea, a region long frequented by large numbers of belugas in summer until their near disappearance in the 1980s. Wide variation in numbers since then suggests a complex recent history that hinders recovery efforts. Analysis of teeth sampled during the historical (pre-decline) era using ancient DNA (aDNA) methods found that the original Kotzebue Sound whales were differentiated for mitochondrial DNA (mtDNA) from other summering concentrations across the Pacific Arctic revealing a demographically distinct subpopulation where long-established migratory culture likely facilitated population divergence. Analysis of microsatellite (nDNA) and mtDNA markers in belugas from the contemporary (post-decline) era revealed that whales from other stocks likely visited Kotzebue Sound, including during two low ice years when relatively large numbers of whales were present. Some mtDNA lineages were found only in Kotzebue Sound, with one recorded in both the historical and contemporary eras. Exclusion tests found a number of whales in Kotzebue Sound during the contemporary era that had nDNA genotypes unlikely to arise in other contemporary stocks in the Pacific Arctic. Our findings indicate that the Kotzebue Sound belugas comprised a unique stock of which a few remnants likely still co-occur with belugas from other larger stocks. We recommend that the US government work through the co-management process to greatly reduce or eliminate the taking of belugas, especially adult females, likely to belong to the Kotzebue Sound stock, until they recover.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49031632","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}
T. Romano, L. A. Thompson, Maureen V. Driscoll, E. Unal, A. Tuttle, Gayle Sirpenski, MaryEllen Mateleska, Dale Wolbrink
Aquaria that care for and maintain belugas (Delphinapterus leucas) under professional care have the opportunity to contribute to the conservation of wild belugas through research, expertise in animal care and husbandry, and engaging and educating the public about threats to the species’ health and population sustainability. In an aquarium setting, belugas can be studied under controlled conditions, with known variables that are often difficult to discern when studying wild belugas. Information on nutrition, health status and environmental parameters can be easily obtained in a controlled setting. Biological samples are collected from professionally trained whales that voluntarily participate in informative experimental paradigms. Research studies in aquaria seek to contribute to the recovery and management of endangered beluga populations, such as those in Cook Inlet. Mystic Aquarium’s efforts are presented as a case study. Key research priorities address action items in the Cook Inlet Beluga Recovery Plan and include: (1) understanding the beluga immune system, microbial communities, pathogens and disease; (2) development of non-invasive methods for assessing reproductive status, body condition and health in wild whales; (3) investigation of diving physiology and the impact of altered dive patterns on health; (4) understanding reproduction, a key to recovery and sustainability of wild populations; (5) development and testing of new technologies for tracking and monitoring whales and habitat use; and (6) understanding how noise affects beluga hearing, behaviour and physiology. Expertise in animal handling, behaviour and nutrition contribute to rescue, rehabilitation and capture release efforts. Moreover, ‘students’ of all ages have the opportunity to be engaged, educated and contribute to beluga conservation.
{"title":"The role of aquaria in beluga research and conservation","authors":"T. Romano, L. A. Thompson, Maureen V. Driscoll, E. Unal, A. Tuttle, Gayle Sirpenski, MaryEllen Mateleska, Dale Wolbrink","doi":"10.33265/polar.v40.5567","DOIUrl":"https://doi.org/10.33265/polar.v40.5567","url":null,"abstract":"Aquaria that care for and maintain belugas (Delphinapterus leucas) under professional care have the opportunity to contribute to the conservation of wild belugas through research, expertise in animal care and husbandry, and engaging and educating the public about threats to the species’ health and population sustainability. In an aquarium setting, belugas can be studied under controlled conditions, with known variables that are often difficult to discern when studying wild belugas. Information on nutrition, health status and environmental parameters can be easily obtained in a controlled setting. Biological samples are collected from professionally trained whales that voluntarily participate in informative experimental paradigms. Research studies in aquaria seek to contribute to the recovery and management of endangered beluga populations, such as those in Cook Inlet. Mystic Aquarium’s efforts are presented as a case study. Key research priorities address action items in the Cook Inlet Beluga Recovery Plan and include: (1) understanding the beluga immune system, microbial communities, pathogens and disease; (2) development of non-invasive methods for assessing reproductive status, body condition and health in wild whales; (3) investigation of diving physiology and the impact of altered dive patterns on health; (4) understanding reproduction, a key to recovery and sustainability of wild populations; (5) development and testing of new technologies for tracking and monitoring whales and habitat use; and (6) understanding how noise affects beluga hearing, behaviour and physiology. Expertise in animal handling, behaviour and nutrition contribute to rescue, rehabilitation and capture release efforts. Moreover, ‘students’ of all ages have the opportunity to be engaged, educated and contribute to beluga conservation.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41858921","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}
C. Goertz, K. Woodie, Brett V. Long, Lisa H. Hartman, E. Gaglione, Dennis Christen, T. Clauss, J. Flower, A. Tuttle, Carey Richard, T. Romano, T. Schmitt, Eric Otjen, S. Osborn, Steve Aibel, T. Binder, W. Van Bonn, M. Castellote, T. A. Mooney, S. Dennison-Gibby, K. Burek‐Huntington, T. Rowles
Given the remote, rugged areas belugas typically inhabit and the low rehabilitation success rate with any cetacean, it is rare to have the opportunity to rescue a live-stranded beluga. The Alaska SeaLife Center cared for two stranded beluga calves with two different outcomes. In 2012, a neonatal male beluga calf (DL1202) stranded following intense storms in Bristol Bay. In 2017, a helicopter pilot discovered a stranded male beluga calf (DL1705) during a flight over Cook Inlet. The Alaska SeaLife Center transported both calves for rehabilitation and utilized supportive care plans based on those for other species of stranded cetaceans and care of neonatal belugas at zoological facilities. Diagnostics included complete blood counts, serum chemistries, microbial cultures, hearing tests, imaging and morphometric measurements to monitor systemic health. Treatments included in-pool flotation support; antimicrobials; gastrointestinal support; and close monitoring of respirations, urination, defecation and behaviour. After three weeks of supportive care, the Bristol Bay calf (DL1202) succumbed to sepsis secondary to a possible prematurity-related lack of passive transfer of antibodies. After seven weeks, the Cook Inlet calf (DL1705) recovered and all medications were discontinued. Unable to survive on his own, he was declared non-releasable and placed in long-term care at a zoological facility, to live with other belugas. Aspects and details from successful cases of cetacean critical care become important references especially vital for the survival of essential animals in small, endangered populations.
{"title":"Stranded beluga (Delphinapterus leucas) calf response and care: reports of two cases with different outcomes","authors":"C. Goertz, K. Woodie, Brett V. Long, Lisa H. Hartman, E. Gaglione, Dennis Christen, T. Clauss, J. Flower, A. Tuttle, Carey Richard, T. Romano, T. Schmitt, Eric Otjen, S. Osborn, Steve Aibel, T. Binder, W. Van Bonn, M. Castellote, T. A. Mooney, S. Dennison-Gibby, K. Burek‐Huntington, T. Rowles","doi":"10.33265/polar.v40.5514","DOIUrl":"https://doi.org/10.33265/polar.v40.5514","url":null,"abstract":"Given the remote, rugged areas belugas typically inhabit and the low rehabilitation success rate with any cetacean, it is rare to have the opportunity to rescue a live-stranded beluga. The Alaska SeaLife Center cared for two stranded beluga calves with two different outcomes. In 2012, a neonatal male beluga calf (DL1202) stranded following intense storms in Bristol Bay. In 2017, a helicopter pilot discovered a stranded male beluga calf (DL1705) during a flight over Cook Inlet. The Alaska SeaLife Center transported both calves for rehabilitation and utilized supportive care plans based on those for other species of stranded cetaceans and care of neonatal belugas at zoological facilities. Diagnostics included complete blood counts, serum chemistries, microbial cultures, hearing tests, imaging and morphometric measurements to monitor systemic health. Treatments included in-pool flotation support; antimicrobials; gastrointestinal support; and close monitoring of respirations, urination, defecation and behaviour. After three weeks of supportive care, the Bristol Bay calf (DL1202) succumbed to sepsis secondary to a possible prematurity-related lack of passive transfer of antibodies. After seven weeks, the Cook Inlet calf (DL1705) recovered and all medications were discontinued. Unable to survive on his own, he was declared non-releasable and placed in long-term care at a zoological facility, to live with other belugas. Aspects and details from successful cases of cetacean critical care become important references especially vital for the survival of essential animals in small, endangered populations.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43438326","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. Frost, Tom Gray, Willie Goodwin, Sr., Roswell Schaeffer, R. Suydam
The Alaska Beluga Whale Committe (ABWC) was formed in 1988 to conserve beluga whales (Delphinapterus leucas) and manage beluga subsistence hunting in western and northern Alaska in cooperation with the National Marine Fisheries Service (NMFS). When the ABWC was formed, there was no consistently funded research or management programme for belugas in Alaska, and co-management was a new concept. The ABWC brought together representatives from beluga hunting communities; federal, state, tribal and local governments; and beluga researchers to develop and implement a programme to manage belugas. With funding from NMFS and others, the ABWC has collected data necessary for informed management decisions including the following: harvest data; aerial surveys of belugas in Bristol Bay and the eastern Bering and Chukchi seas; beluga tracking studies, including training hunters to attach transmitters; a pioneering genetics study of beluga stock identity that has facilitated collection of >2000 beluga skin samples; and a genetics-based mark–recapture study to estimate beluga abundance in Bristol Bay and validate aerial survey estimates. The ABWC is currently engaged in regional management planning in Kotzebue Sound and the eastern Bering Sea. It produces results that are scientifically valid, locally accepted and cost-effective and is an example of what can be achieved when Native hunters, scientists and managing agencies respect and listen to one another and work together. However, the current NMFS co-management funding process has fundamentally altered the relationship between NMFS and ABWC, with NMFS now acting more like a funding agency than a partner.
{"title":"Alaska Beluga Whale Committee—a unique model of co-management","authors":"K. Frost, Tom Gray, Willie Goodwin, Sr., Roswell Schaeffer, R. Suydam","doi":"10.33265/polar.v40.5611","DOIUrl":"https://doi.org/10.33265/polar.v40.5611","url":null,"abstract":"The Alaska Beluga Whale Committe (ABWC) was formed in 1988 to conserve beluga whales (Delphinapterus leucas) and manage beluga subsistence hunting in western and northern Alaska in cooperation with the National Marine Fisheries Service (NMFS). When the ABWC was formed, there was no consistently funded research or management programme for belugas in Alaska, and co-management was a new concept. The ABWC brought together representatives from beluga hunting communities; federal, state, tribal and local governments; and beluga researchers to develop and implement a programme to manage belugas. With funding from NMFS and others, the ABWC has collected data necessary for informed management decisions including the following: harvest data; aerial surveys of belugas in Bristol Bay and the eastern Bering and Chukchi seas; beluga tracking studies, including training hunters to attach transmitters; a pioneering genetics study of beluga stock identity that has facilitated collection of >2000 beluga skin samples; and a genetics-based mark–recapture study to estimate beluga abundance in Bristol Bay and validate aerial survey estimates. The ABWC is currently engaged in regional management planning in Kotzebue Sound and the eastern Bering Sea. It produces results that are scientifically valid, locally accepted and cost-effective and is an example of what can be achieved when Native hunters, scientists and managing agencies respect and listen to one another and work together. However, the current NMFS co-management funding process has fundamentally altered the relationship between NMFS and ABWC, with NMFS now acting more like a funding agency than a partner.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44655881","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. Breton-Honeyman, H. Huntington, Mark Basterfield, Kiyo Campbell, J. Dicker, Tom Gray, Alfred E.R. Jakobsen, Frankie Jean-Gagnon, David Lee, R. Laing, L. Loseto, P. McCarney, John Noksana Jr, Tommy Palliser, Lawrence Ruben, Clayton Tartak, Joseph Townley, E. Zdor
Beluga whales ( Delphinapterus leucas ) are an integral part of many Arctic Indigenous cultures and contribute to food security for communities from Greenland, across northern Canada and Alaska to Chukotka, Russia. Although the harvesting and stewardship practices of Indigenous peoples vary among regions and have shifted and adapted over time, central principles of respect for beluga and sharing of the harvest have remained steadfast. In addition to intra-community cooperation to harvest, process and use beluga whales, rapid environmental change in the Arctic has underscored the need for inter-re-gional communication as well as collaboration with scientists and managers to sustain beluga populations and their cultural and nutritional roles in Arctic communities. Our paper, written by the overlapping categories of researchers, hunters, and managers, first provides an overview of beluga hunting and collaborative research in seven regions of the Arctic (Greenland; Nunatsiavut, Nunavik, Nunavut, and the Inuvialuit Settlement Region, Canada; Alaska; and Chukotka). Then we present a more detailed case study of collaboration, exam-ining a recent research and management project that utilizes co-production of knowledge to address the conservation of a depleted population of beluga in Nunavik, Canada. We conclude that sustaining traditional values, establishing collaborative management efforts, the equitable inclusion of Indigenous Knowledge, and respectful and meaningful collaborations among hunters, researchers and managers are essential to sustaining healthy beluga populations and the peoples who live with and depend upon them in a time of rapid social and environmental change.
{"title":"Beluga whale stewardship and collaborative research practices among Indigenous peoples in the Arctic","authors":"K. Breton-Honeyman, H. Huntington, Mark Basterfield, Kiyo Campbell, J. Dicker, Tom Gray, Alfred E.R. Jakobsen, Frankie Jean-Gagnon, David Lee, R. Laing, L. Loseto, P. McCarney, John Noksana Jr, Tommy Palliser, Lawrence Ruben, Clayton Tartak, Joseph Townley, E. Zdor","doi":"10.33265/polar.v40.5522","DOIUrl":"https://doi.org/10.33265/polar.v40.5522","url":null,"abstract":"Beluga whales ( Delphinapterus leucas ) are an integral part of many Arctic Indigenous cultures and contribute to food security for communities from Greenland, across northern Canada and Alaska to Chukotka, Russia. Although the harvesting and stewardship practices of Indigenous peoples vary among regions and have shifted and adapted over time, central principles of respect for beluga and sharing of the harvest have remained steadfast. In addition to intra-community cooperation to harvest, process and use beluga whales, rapid environmental change in the Arctic has underscored the need for inter-re-gional communication as well as collaboration with scientists and managers to sustain beluga populations and their cultural and nutritional roles in Arctic communities. Our paper, written by the overlapping categories of researchers, hunters, and managers, first provides an overview of beluga hunting and collaborative research in seven regions of the Arctic (Greenland; Nunatsiavut, Nunavik, Nunavut, and the Inuvialuit Settlement Region, Canada; Alaska; and Chukotka). Then we present a more detailed case study of collaboration, exam-ining a recent research and management project that utilizes co-production of knowledge to address the conservation of a depleted population of beluga in Nunavik, Canada. We conclude that sustaining traditional values, establishing collaborative management efforts, the equitable inclusion of Indigenous Knowledge, and respectful and meaningful collaborations among hunters, researchers and managers are essential to sustaining healthy beluga populations and the peoples who live with and depend upon them in a time of rapid social and environmental change.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41958262","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}
Heterotrophic flagellates are essential components of the marine microbial food web. However, how the changes in flagellate populations reflect environmental changes in marine ecosystems is still unclear, especially in polar regions. In this study, we used pyrosequencing to examine the community structure of heterotrophic flagellates (HFs) in the Powell Basin’s surface waters of the northern Antarctic Peninsula. OTUs (operational taxonomic units) of different taxa and the correlations between community structure and environmental factors were analysed. Eight taxa of HFs were selected for the principal analysis: Telonemia, Picozoa, Rhizaria, Amoebozoa, Apusomonas, Centrohelida, Choanomonada and marine stramenopiles (MASTs). The HFs were defined as heterotrophic picoflagellates (HPFs; <3 μm) and heterotrophic nanoflagellates (HNFs; >3 μm, <20 μm), which had similar dominant phyla (MASTs and Telonemia). However, their taxonomic composition differed. Environmental factors exerted similar effects on the community structure of both HPFs and HNPs. Compared with the correlation between HPF and environmental factors, the correlation between HNF and environmental factors was stronger. Salinity, bacterial biomass and the biological interactions amongst dominant taxa were the main variables to influence the diversity and community structure of HFs.
{"title":"Diversity and distribution of heterotrophic flagellates in seawater of the Powell Basin, Antarctic Peninsula","authors":"Zhiyi Chen, Jian-feng He, Shunan Cao, Zhibo Lu, Musheng Lan, Hongyuan Zheng, Guangfu Luo, Fang Zhang","doi":"10.33265/polar.v40.5389","DOIUrl":"https://doi.org/10.33265/polar.v40.5389","url":null,"abstract":"Heterotrophic flagellates are essential components of the marine microbial food web. However, how the changes in flagellate populations reflect environmental changes in marine ecosystems is still unclear, especially in polar regions. In this study, we used pyrosequencing to examine the community structure of heterotrophic flagellates (HFs) in the Powell Basin’s surface waters of the northern Antarctic Peninsula. OTUs (operational taxonomic units) of different taxa and the correlations between community structure and environmental factors were analysed. Eight taxa of HFs were selected for the principal analysis: Telonemia, Picozoa, Rhizaria, Amoebozoa, Apusomonas, Centrohelida, Choanomonada and marine stramenopiles (MASTs). The HFs were defined as heterotrophic picoflagellates (HPFs; <3 μm) and heterotrophic nanoflagellates (HNFs; >3 μm, <20 μm), which had similar dominant phyla (MASTs and Telonemia). However, their taxonomic composition differed. Environmental factors exerted similar effects on the community structure of both HPFs and HNPs. Compared with the correlation between HPF and environmental factors, the correlation between HNF and environmental factors was stronger. Salinity, bacterial biomass and the biological interactions amongst dominant taxa were the main variables to influence the diversity and community structure of HFs.","PeriodicalId":49684,"journal":{"name":"Polar Research","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2021-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42662478","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}
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":"2004 2","pages":""},"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":" ","pages":""},"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}
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