Pub Date : 2023-04-01DOI: 10.1017/S0954102023000068
Florencia Bertoglio, C. Piccini, R. Urrutia, D. Antoniades
Abstract Fildes Peninsula, on King George Island, has been greatly influenced by recent rapid climate warming. Lakes are pervasive features of Fildes Peninsula landscapes, some of which are used as water sources for Antarctic stations. We studied seven Fildes Peninsula lakes to explore differences among lakes and between seasons in phytoplankton and bacterioplankton communities. We measured environmental variables, analysed pigments using high-performance liquid chromatography and examined bacterial DNA through high-throughput sequencing of the 16S rRNA gene. The main driver structuring microbial communities was the season (i.e. spring vs autumn). Chlorophyceae were the dominant phytoplankton group in all lakes and both seasons. Indicator bacteria for each season were identified, including Flavobacterium, Polaromonas and Oxalobacteraceae as indicators of spring conditions under thick ice, whereas Frankiales and Verrucomicrobia were indicator species of autumn following the ice-free summer. The indicator species for spring are generally observed in oligotrophic conditions, whereas many of the autumn indicators are commonly found in soils. There were lesser between-lake differences in microbial communities in autumn, at the end of the open-water period, than in spring at the end of the ice-covered period. This study will act as the basis for future assessments of changes in aquatic microbial communities.
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Pub Date : 2023-04-01DOI: 10.1017/S0954102023000056
W. Nel, D. Hedding, E. Rudolph
WERNER NEL 1, DAVID W. HEDDING 2 and ELIZABETH M. RUDOLPH 3 Department of Geography and Environmental Science, University of Fort Hare, 1 King Williamstown Road, Alice, 5700, South Africa Department of Geography, University of South Africa, Pioneer Avenue, Florida, 1710, South Africa Afromontane Research Unit, Department of Geography, University of the Free State, 205 Nelson Mandela Avenue, Bloemfontein, 9300, South Africa wnel@ufh.ac.za
WERNER NEL 1、DAVID W.HEDDING 2和ELIZABETH M.RUDOLPH 3爱丽丝威廉斯敦国王路1号黑尔堡大学地理与环境科学系，5700年，佛罗里达州先锋大道南非大学南非地理系，1710年，纳尔逊·曼德拉大道205号，自由邦大学地理系南非非洲人研究所，布隆方丹，9300，南非wnel@ufh.ac.za
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Pub Date : 2023-04-01DOI: 10.1017/S0954102023000081
S. Robinson
In the 1980s, British Antarctic scientists (Farman et al. 1985) discovered the hole in the ozone layer over Antarctica, and we are now familiar with images of springtime ozone depletion extending beyond the continental margins (Fig. 1a). The largest Antarctic ozone hole occurred in 2006 (Fig. 1b), but in recent years recovery has started to become apparent, with the total column ozone predicted to return to 1980 levels by 2066 (WMO 2022). However, there is still reason to be concerned about the timing and extent of ultraviolet (UV) radiation exposure in Antarctica, as well as how ozone recovery may be jeopardized by climate change-mediated events such as wildfires. The ozone layer protects the Earth's surface from damaging UV-B radiation. Recent reports demonstrate that over the period of maximum ozone depletion (1990–2020) the maximum spring UV index at Palmer Station (64°S) has increased by 2.5 times compared to the pre-ozone hole era as measured in the early 1970s. Despite the solar angle being much lower in Antarctica, the maximum UV index at Palmer Station in spring can now sometimes exceed that experienced in summer in subtropical regions (San Diego, CA, 32°N; Bernard et al. 2022; Environmental Effects Assessment Panel in press). Antarctic ozone depletion generally peaks between September and October, when most Antarctic terrestrial vegetation and soil biota will be frozen, dormant and hopefully protected under snow cover. Similarly, much marine life will be protected by sea-ice cover, although some seals and birds might be breeding on the ice at this time. Usually by the time summer arrives the ozone layer has recovered (see white lines in Fig. 1c). However, for the past 3 years ozone depletion has been extensive (Fig. 1b) and long-lasting, extending into early summer (e.g. 2022; see black lines in Fig. 1c). Since 2019, November–December total ozone column depth for latitudes 60–90°S have been the lowest since records began in the 1980s (NASA 2023). From a biologist's perspective, ozone depletion in early December is far more concerning, given that this is closer to the solstice, meaning that all solar radiation is higher, including the UV index. A peak in UV index coincident with snowmelt and the emergence of vegetation as well as during the peak breeding season at the start of the summer is of particular concern, as more biota are likely to be exposed to this higher incident UV-B radiation. For some organisms, such exposure may also occur at a more vulnerable time in their life cycles. The effects of climate change through earlier snowmelt and heatwaves (Robinson et al. 2020, Environmental Effects Assessment Panel in press) is likely to be enhancing the spring and summer UV exposure of Antarctic organisms, as noted in the latest United Nations Environment Program Environmental Effects Assessment Panel report (Barnes et al. 2023; Environmental Effects Assessment Panel in press). The Montreal Protocol is an extremely successful environment
在20世纪80年代，英国南极科学家(Farman et al. 1985)发现了南极洲上空的臭氧层空洞，我们现在熟悉了春季臭氧消耗延伸到大陆边缘以外的图像(图1a)。南极最大的臭氧空洞发生在2006年(图1b)，但近年来已经开始明显恢复，预计到2066年臭氧柱总量将恢复到1980年的水平(WMO 2022)。然而，仍有理由担心南极洲紫外线照射的时间和程度，以及野火等气候变化介导的事件如何危及臭氧恢复。臭氧层保护地球表面免受有害的UV-B辐射。最近的报告表明，在最大臭氧消耗期间(1990-2020年)，Palmer站(64°S)的最大春季紫外线指数与1970年代初测量的臭氧空洞前时代相比增加了2.5倍。尽管南极洲的太阳角度要低得多，但帕尔默站春季的最大紫外线指数有时会超过亚热带地区夏季的最大值(圣地亚哥，加利福尼亚，32°N;Bernard et al. 2022;环境影响评估小组(已出版)。南极臭氧消耗通常在9月至10月达到高峰，那时大多数南极陆地植被和土壤生物群将被冻结、休眠，并有望被积雪覆盖。同样，许多海洋生物将受到海冰覆盖的保护，尽管一些海豹和鸟类可能在这个时候在冰上繁殖。通常到夏季到来时，臭氧层已经恢复(见图1c中的白线)。然而，在过去3年中，臭氧消耗范围广泛(图1b)且持续时间长，一直延续到初夏(如2022年;见图1c中的黑线)。自2019年以来，60-90°S纬度地区11月至12月的臭氧柱总深度是自20世纪80年代有记录以来的最低水平(NASA 2023)。从生物学家的角度来看，12月初的臭氧消耗更令人担忧，因为这更接近冬至，这意味着所有的太阳辐射都更高，包括紫外线指数。紫外线指数的峰值与融雪和植被的出现以及夏初的繁殖期一致，这是特别值得关注的，因为更多的生物群可能会暴露在这种较高的UV- b辐射下。对某些生物来说，这种接触也可能发生在其生命周期中较脆弱的时期。正如联合国环境规划署环境影响评估小组最新报告(Barnes et al. 2023;环境影响评估小组(已出版)。《蒙特利尔议定书》是一项极为成功的环境条约。由于该条约，消耗臭氧层化合物(如氟氯化碳;氯氟烃)已经得到控制，预计到2066年臭氧层将恢复(WMO 2022)。根据《蒙特利尔议定书》及其2016年基加利修正案采取的行动也有助于减少温室气体排放和减缓全球气温上升，方法是用不会导致气候强迫的化合物取代导致温室气体排放的氟氯化碳。据估计，这已在中纬度地区防止了至少0.5-1.0°C的变暖，并在北极地区防止了超过1.0°C的变暖(WMO 2022;环境影响评估小组(已出版)。但我们不能自满。近年来观测到的延长的臭氧消耗可能在一定程度上因气候变化的影响而加剧。最近的两个大型臭氧空洞受到不同事件的影响:2019-2020年澳大利亚黑夏森林大火和2021年La Soufriere火山喷发(Yook et al. 2022)。研究表明，澳大利亚大面积的野火向平流层注入了能够消耗臭氧的气溶胶(Damany et al. 2022;Yook et al. 2022)，并可能导致2020年臭氧空洞面积增大(图1b;Solomon et al. 2023)。不像臭氧的原始原因doi:10.1017/S0954102023000081
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Pub Date : 2023-03-01DOI: 10.1017/S0954102023000019
B. Ball, P. Convey, K. L. Feeser, U. Nielsen, David Van Horn
Abstract Antarctic soils provide an excellent setting to test biogeographical patterns across spatial and environmental scales given their relatively simple communities and the dominance of physical factors that create strong environmental gradients. Additional urgency is given by the fact that their unique terrestrial communities are the subject of conservation efforts in a rapidly changing environment. We investigated relationships of soil community assembly and alpha and beta diversity with climatic and environmental parameters across regional and local scales in Maritime Antarctica. We sampled from a regional gradient of sites that differ in habitat severity, ranging from relatively favourable to harsher physicochemical conditions. At the regional scale, bacterial community characteristics and microarthropod abundance varied along this severity gradient, but most measures of fungal communities did not. Microarthropod and microbial communities differed in which soil and climate parameters were most influential, and the specific parameters that influenced each taxon differed across broad and fine spatial scales. This suggests that conservation efforts will need to focus on a large variety of habitat characteristics to successfully encompass diversity across taxa. Because beta diversity was the result of species turnover, conservation efforts also cannot focus on only the most biodiverse sites to effectively preserve all aspects of biodiversity.
{"title":"Habitat severity characteristics structure soil communities at regional and local spatial scales along the Antarctica Peninsula","authors":"B. Ball, P. Convey, K. L. Feeser, U. Nielsen, David Van Horn","doi":"10.1017/S0954102023000019","DOIUrl":"https://doi.org/10.1017/S0954102023000019","url":null,"abstract":"Abstract Antarctic soils provide an excellent setting to test biogeographical patterns across spatial and environmental scales given their relatively simple communities and the dominance of physical factors that create strong environmental gradients. Additional urgency is given by the fact that their unique terrestrial communities are the subject of conservation efforts in a rapidly changing environment. We investigated relationships of soil community assembly and alpha and beta diversity with climatic and environmental parameters across regional and local scales in Maritime Antarctica. We sampled from a regional gradient of sites that differ in habitat severity, ranging from relatively favourable to harsher physicochemical conditions. At the regional scale, bacterial community characteristics and microarthropod abundance varied along this severity gradient, but most measures of fungal communities did not. Microarthropod and microbial communities differed in which soil and climate parameters were most influential, and the specific parameters that influenced each taxon differed across broad and fine spatial scales. This suggests that conservation efforts will need to focus on a large variety of habitat characteristics to successfully encompass diversity across taxa. Because beta diversity was the result of species turnover, conservation efforts also cannot focus on only the most biodiverse sites to effectively preserve all aspects of biodiversity.","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"103 - 119"},"PeriodicalIF":1.6,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47693382","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}
Pub Date : 2023-03-01DOI: 10.1017/S0954102022000451
P. Doran, K. Myers, C. Mckay, D. Bromwich
The McMurdo Dry Valleys in East Antarctica represents the largest ice-free area on the continent. In 1993, the National Science Foundation (NSF) funded the McMurdo Long Term Ecological Research (MCM LTER) site, which built a meteorological network that included a station on the shore of Lake Vida (LVi) in Victoria Valley (VV) installed in 1995 (Doran et al. 1995). This Short Note describes the conditions surrounding the lowest temperature ever recorded in the McMurdo Dry Valleys at LVi and compares them to other nearby meteorological stations.
东南极洲的麦克默多干谷是南极洲最大的无冰区。1993年，美国国家科学基金会(NSF)资助了麦克默多长期生态研究(MCM LTER)站点，该站点建立了一个气象网络，其中包括1995年在维多利亚谷(VV)维达湖(LVi)岸边安装的一个站点(Doran et al. 1995)。这篇短文描述了LVi麦克默多干谷有史以来记录的最低温度周围的条件，并将它们与附近的其他气象站进行了比较。
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Pub Date : 2023-02-01DOI: 10.1017/S095410202300007X
P. Convey
TheAntarctic Treaty System (ATS) is often paraphrased as providing the means by which Antarctica is protected as a 'continent for peace and science', on the face of it meaning that the primary purpose of humans being present in Antarctica is for the advancement of scientific knowledge. As is well known, some of the earliest expeditions to Antarctica placed scientific discovery and exploration amongst their highest priorities. Scientific research in Antarctica really took off with the International Geophysical Year of 1957/58, illustrating that even then the importance of Antarctica in the global system and for the advancement of science was starting to be appreciated. Even today, the lack of knowledge of parts of the continent and surrounding ocean, and/or within particular disciplines, means that 'discovery science' still has a major role to play. With today's emphasis and focus on the multifaceted field of 'global climate change', it is often easy to forget that little more than 30 years ago the concept was barely mentioned or its importance widely appreciated. So, what were the major drivers of the rapid development of Antarctic science in the midto late-20 Century, before 'climate fever' took over, and to what extent do these still apply? Perhaps more provocatively, does science itself really drive the actions and plans of those nations operating in Antarctica, or is it more accurate to see 'the tail wagging the dog', with scientific priorities and cooperation trailing behind geopolitical manoeuvring and the maximising of national prestige within the ATS? Antarctica has always fascinated humans, whether scientists or not. From both scientific and personal perspectives, it provides some of the planet's extremes and superlatives. With most of the world's ice, lowest temperatures, importance as an upper atmospheric and space observatory and surrounded by the most powerful ocean current, it has long been central to glaciological, geological, tectonic, atmospheric and oceanographic studies. Its extreme environments quickly catalysed research into the evolution and exceptional survival abilities of its resident biota – remarkably diverse in the surrounding ocean and equally remarkably sparse on land, but both sharing very long-term histories in the region. There is still much to learn in all these fields, especially at the boundaries between traditionally distinct disciplines, in what used to be known as 'pure' research, or philosophical recognition of the value of knowledge itself. In today's world, Antarctica and the Southern Ocean play key roles as 'sentinels' for change across the globe, not only relating to climate, but also areas like pollution, erosion of biogeography, space weather and the importance of wilderness values. Their roles as the 'engine' for the global ocean circulation system and a key driver of global climate now take prominence. However, it could be suggested that researchers who cannot connect what they do in someway to 'cli
{"title":"What is the place of science in Antarctica?","authors":"P. Convey","doi":"10.1017/S095410202300007X","DOIUrl":"https://doi.org/10.1017/S095410202300007X","url":null,"abstract":"TheAntarctic Treaty System (ATS) is often paraphrased as providing the means by which Antarctica is protected as a 'continent for peace and science', on the face of it meaning that the primary purpose of humans being present in Antarctica is for the advancement of scientific knowledge. As is well known, some of the earliest expeditions to Antarctica placed scientific discovery and exploration amongst their highest priorities. Scientific research in Antarctica really took off with the International Geophysical Year of 1957/58, illustrating that even then the importance of Antarctica in the global system and for the advancement of science was starting to be appreciated. Even today, the lack of knowledge of parts of the continent and surrounding ocean, and/or within particular disciplines, means that 'discovery science' still has a major role to play. With today's emphasis and focus on the multifaceted field of 'global climate change', it is often easy to forget that little more than 30 years ago the concept was barely mentioned or its importance widely appreciated. So, what were the major drivers of the rapid development of Antarctic science in the midto late-20 Century, before 'climate fever' took over, and to what extent do these still apply? Perhaps more provocatively, does science itself really drive the actions and plans of those nations operating in Antarctica, or is it more accurate to see 'the tail wagging the dog', with scientific priorities and cooperation trailing behind geopolitical manoeuvring and the maximising of national prestige within the ATS? Antarctica has always fascinated humans, whether scientists or not. From both scientific and personal perspectives, it provides some of the planet's extremes and superlatives. With most of the world's ice, lowest temperatures, importance as an upper atmospheric and space observatory and surrounded by the most powerful ocean current, it has long been central to glaciological, geological, tectonic, atmospheric and oceanographic studies. Its extreme environments quickly catalysed research into the evolution and exceptional survival abilities of its resident biota – remarkably diverse in the surrounding ocean and equally remarkably sparse on land, but both sharing very long-term histories in the region. There is still much to learn in all these fields, especially at the boundaries between traditionally distinct disciplines, in what used to be known as 'pure' research, or philosophical recognition of the value of knowledge itself. In today's world, Antarctica and the Southern Ocean play key roles as 'sentinels' for change across the globe, not only relating to climate, but also areas like pollution, erosion of biogeography, space weather and the importance of wilderness values. Their roles as the 'engine' for the global ocean circulation system and a key driver of global climate now take prominence. However, it could be suggested that researchers who cannot connect what they do in someway to 'cli","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"1 - 3"},"PeriodicalIF":1.6,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46552589","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}
Pub Date : 2023-02-01DOI: 10.1017/S0954102022000384
Pamela Olmedo-Rojas, Gert‐Jan Jeunen, M. Lamare, Johanna D. Turnbull, A. Terauds, N. Gemmell, Ceridwen I. Fraser
Abstract Environmental DNA is a powerful tool for monitoring biodiversity. Although environmental DNA surveys have successfully been implemented in various environments, protocol choice has been shown to affect results and inferences. Thus far, few method comparison studies for soil have been undertaken. Here, we optimized the workflow for soil metabarcoding through a comparative study encompassing variation in sampling strategy (individual and combined samples), DNA extraction (PowerSoil®, NucleoSpin® Soil, PowerSoil® + phosphate buffer and NucleoSpin® Soil + phosphate buffer) and library preparation (one-step and two-step quantitative polymerase chain reaction methods). Using a partial 18S rRNA marker, a total of 309 eukaryotic taxa across 21 phyla were identified from Antarctic soil from one site in the Larsemann Hills. Our optimized workflow was effective with no notable reduction in data quality for a considerable increase in time and cost efficiency. The NucleoSpin® Soil + phosphate buffer was the best-performing extraction method. Compared to similar studies in other regions, we obtained low taxonomic coverage, perhaps because of the paucity of Antarctic terrestrial organisms in genetic reference databases. Our findings provide useful methodological insights for maximizing efficiency in soil metabarcoding studies in Antarctica and other low-biomass environments.
{"title":"Soil environmental DNA metabarcoding in low-biomass regions requires protocol optimization: a case study in Antarctica","authors":"Pamela Olmedo-Rojas, Gert‐Jan Jeunen, M. Lamare, Johanna D. Turnbull, A. Terauds, N. Gemmell, Ceridwen I. Fraser","doi":"10.1017/S0954102022000384","DOIUrl":"https://doi.org/10.1017/S0954102022000384","url":null,"abstract":"Abstract Environmental DNA is a powerful tool for monitoring biodiversity. Although environmental DNA surveys have successfully been implemented in various environments, protocol choice has been shown to affect results and inferences. Thus far, few method comparison studies for soil have been undertaken. Here, we optimized the workflow for soil metabarcoding through a comparative study encompassing variation in sampling strategy (individual and combined samples), DNA extraction (PowerSoil®, NucleoSpin® Soil, PowerSoil® + phosphate buffer and NucleoSpin® Soil + phosphate buffer) and library preparation (one-step and two-step quantitative polymerase chain reaction methods). Using a partial 18S rRNA marker, a total of 309 eukaryotic taxa across 21 phyla were identified from Antarctic soil from one site in the Larsemann Hills. Our optimized workflow was effective with no notable reduction in data quality for a considerable increase in time and cost efficiency. The NucleoSpin® Soil + phosphate buffer was the best-performing extraction method. Compared to similar studies in other regions, we obtained low taxonomic coverage, perhaps because of the paucity of Antarctic terrestrial organisms in genetic reference databases. Our findings provide useful methodological insights for maximizing efficiency in soil metabarcoding studies in Antarctica and other low-biomass environments.","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"15 - 30"},"PeriodicalIF":1.6,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43033253","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}
Pub Date : 2023-02-01DOI: 10.1017/S0954102022000487
M. González-Aravena, L. Krüger, L. Rebolledo, R. Jaña, A. Aguayo‐Lobo, Marcelo A. Leppe, R. Rondón, F. Santa-Cruz, Carla Salinas, C. Trevisan, C. A. Cárdenas
Abstract The changes implemented in 2005 in the development strategies of Antarctic science carried out by Chile have had a positive impact on the scientific productivity of the Chilean Antarctic Science Program (PROCIEN). We analysed scientometric indicators from between 2009 and 2019. The bibliographic data were extracted from the Web of Science database using search query keywords. We used multiple correspondence analysis to identify specific trends and also network analyses of international collaboration in VOSviewer. The number of Antarctic science publications in Chile has gradually increased from 21 in 2009 to 95 in 2019. The rise in the number of articles was higher in journals for the first impact factor quartile. Research lines showing increased first-quartile impact factor papers corresponded to Antarctic ecosystems, biotechnology and geosciences. The main geographical domains in which such research activities have been carried out corresponded to in the South Shetland Islands and the Antarctic Peninsula. Fieldwork data are the main sources for the production of scientific articles, and there are three science platforms within which most of these papers concentrate. The diversification of funding sources, the implementation of improvements in the selection process and Chile's alignment with Scientific Committee on Antarctic Research programmes have contributed to improving the science that Chile has developed in Antarctica.
摘要智利在2005年实施的南极科学发展战略的变化对智利南极科学计划（PROCIEN）的科学生产力产生了积极影响。我们分析了2009年至2019年间的科学计量指标。书目数据是使用搜索查询关键字从Web of Science数据库中提取的。我们使用了多重对应分析来确定具体趋势，并对VOSviewer的国际合作进行了网络分析。智利的南极科学出版物数量从2009年的21份逐渐增加到2019年的95份。在第一影响因子四分位数的期刊上，文章数量的增长更高。显示第一个四分位数影响因子论文增加的研究线与南极生态系统、生物技术和地球科学相对应。开展此类研究活动的主要地理区域对应于南设得兰群岛和南极半岛。实地调查数据是撰写科学文章的主要来源，这些论文大多集中在三个科学平台上。资金来源的多样化、选拔过程的改进以及智利与南极研究科学委员会方案的一致性，都有助于改进智利在南极发展的科学。
{"title":"Antarctic science in Chile: a bibliometric analysis of scientific productivity during the 2009–2019 period","authors":"M. González-Aravena, L. Krüger, L. Rebolledo, R. Jaña, A. Aguayo‐Lobo, Marcelo A. Leppe, R. Rondón, F. Santa-Cruz, Carla Salinas, C. Trevisan, C. A. Cárdenas","doi":"10.1017/S0954102022000487","DOIUrl":"https://doi.org/10.1017/S0954102022000487","url":null,"abstract":"Abstract The changes implemented in 2005 in the development strategies of Antarctic science carried out by Chile have had a positive impact on the scientific productivity of the Chilean Antarctic Science Program (PROCIEN). We analysed scientometric indicators from between 2009 and 2019. The bibliographic data were extracted from the Web of Science database using search query keywords. We used multiple correspondence analysis to identify specific trends and also network analyses of international collaboration in VOSviewer. The number of Antarctic science publications in Chile has gradually increased from 21 in 2009 to 95 in 2019. The rise in the number of articles was higher in journals for the first impact factor quartile. Research lines showing increased first-quartile impact factor papers corresponded to Antarctic ecosystems, biotechnology and geosciences. The main geographical domains in which such research activities have been carried out corresponded to in the South Shetland Islands and the Antarctic Peninsula. Fieldwork data are the main sources for the production of scientific articles, and there are three science platforms within which most of these papers concentrate. The diversification of funding sources, the implementation of improvements in the selection process and Chile's alignment with Scientific Committee on Antarctic Research programmes have contributed to improving the science that Chile has developed in Antarctica.","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"46 - 59"},"PeriodicalIF":1.6,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47664750","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}
Pub Date : 2023-02-01DOI: 10.1017/S0954102022000529
A. Peirano, A. Bordone, L. Corgnati, S. Marini
Abstract One-year time-lapse images acquired via an autonomous photo imaging device positioned at a depth of 20 m in Tethys Bay (Ross Sea, Antarctica) on a rocky bottom colonized by the sponge Mycale (Oxymycale) acerata were analysed. Monthly changes in the abundance and activity of the sea star Odontaster validus and sea urchin Sterechinus neumayeri on the sponge and nearby rocky bottom were compared with respect to environmental variables such as pack-ice presence/absence, temperature, salinity and photosynthetically active radiation. Sea urchins were more abundant on the rocky bottom and sponge during the summer and winter, respectively. Sea stars showed a decrease in the number of individuals on the sponge from January to December. The grazing activity of both species reached its maximum in January–April, when increased sunlight contributed to the phytoplankton bloom. The winter months were critical both for O. validus and S. neumayeri; although the red sea star maintained its pattern of activity on the rocky bottoms in terms of searching for food, the sea urchin reduced its activity. Time-lapse monitoring systems coupled with physicochemical sensors showed potential for revealing species behaviour in polar environments, contributing to the elucidation of future changes in coastal communities facing climate change.
{"title":"Time-lapse recording of yearly activity of the sea star Odontaster validus and the sea urchin Sterechinus neumayeri in Tethys Bay (Ross Sea, Antarctica)","authors":"A. Peirano, A. Bordone, L. Corgnati, S. Marini","doi":"10.1017/S0954102022000529","DOIUrl":"https://doi.org/10.1017/S0954102022000529","url":null,"abstract":"Abstract One-year time-lapse images acquired via an autonomous photo imaging device positioned at a depth of 20 m in Tethys Bay (Ross Sea, Antarctica) on a rocky bottom colonized by the sponge Mycale (Oxymycale) acerata were analysed. Monthly changes in the abundance and activity of the sea star Odontaster validus and sea urchin Sterechinus neumayeri on the sponge and nearby rocky bottom were compared with respect to environmental variables such as pack-ice presence/absence, temperature, salinity and photosynthetically active radiation. Sea urchins were more abundant on the rocky bottom and sponge during the summer and winter, respectively. Sea stars showed a decrease in the number of individuals on the sponge from January to December. The grazing activity of both species reached its maximum in January–April, when increased sunlight contributed to the phytoplankton bloom. The winter months were critical both for O. validus and S. neumayeri; although the red sea star maintained its pattern of activity on the rocky bottoms in terms of searching for food, the sea urchin reduced its activity. Time-lapse monitoring systems coupled with physicochemical sensors showed potential for revealing species behaviour in polar environments, contributing to the elucidation of future changes in coastal communities facing climate change.","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"4 - 14"},"PeriodicalIF":1.6,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43927915","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}
Pub Date : 2023-01-12DOI: 10.1017/S0954102022000475
S. Heiser, C. Amsler, S. A. Krueger‐Hadfield
Macroalgae cover up to 80% of the benthos along the western Antarctic Peninsula (WAP; Wiencke & Amsler 2012). One of the most common and widespread members of the understory community is the red macroalga Plocamium sp. (Heiser et al. 2020). It supports among the highest amphipod and gastropod densities and is protected from predation through highly diverse chemical defences (Heiser et al. 2020). Haplotypic diversity, based on the mitochondrial cox1 barcode, showed some evidence of geographical structure as well as correlation with specific chemical defences (Shilling et al. 2021). These coarse patterns of genetic diversity are insufficient to understand the processes structuring populations of Plocamium sp. along the WAP, necessitating the use of more polymorphic, nuclear loci, such as microsatellites. Microsatellites have enabled the empirical quantification of the relative rates of selfing (i.e. self-fertilization) vs outcrossing (e.g. Winn et al. 2011) and sexual vs asexual reproduction (e.g. Vallejo-Marín et al. 2010), but studies have been restricted largely to angiosperms or animals, with far fewer investigations in macroalgae (KruegerHadfield et al. 2021). Plocamium sp., like many macroalgae, has a haploid-diploid life cycle, with free-living diploid tetrasporophytes and free-living haploid gametophytes, which are morphologically indistinguishable unless they are reproductive (Fig. S1; Heiser et al. 2020). Meiosis occurs on the tetrasporophytes, resulting in the release of haploid tetraspores. Tetraspores germinate and develop into male and female gametophytes. Gametes are mitotically produced by the gametophytes, but, following fertilization, the zygote is retained on the female gametophyte, where the carposporophyte develops. Each diploid carpospore can germinate into a tetrasporophyte. In natural populations, many thalli are vegetative, rendering it difficult to distinguish the stages. This life cycle results in unique eco-evolutionary consequences that challenge traditional understanding and the utility of common proxies to describe patterns of reproductive system variation (Krueger-Hadfield et al. 2021). For example, Plocamium sp. has separate sexes, but this does not preclude selfing (intergametophytic selfing; see Klekowski 1969). Separate sexes, therefore, cannot be used as a proxy to deduce outcrossing in natural populations. Instead, we must use population genetic tools to empirically quantify the relative rates of selfing, outcrossing and asexual reproduction in natural populations. We developed microsatellites to quantify patterns of genetic diversity and gene flow in Plocamium sp. (Heiser 2022). We chose microsatellites over other approaches for several reasons: 1) microsatellites facilitate the iterative addition of new samples to a dataset, something that is not possible in most genotyping by sequencing (GBS) approaches to identify single nucleotide polymorphisms; 2) microsatellites are an appropriate tool when existing data
{"title":"Microsatellite locus development in the seaweed Plocamium sp.","authors":"S. Heiser, C. Amsler, S. A. Krueger‐Hadfield","doi":"10.1017/S0954102022000475","DOIUrl":"https://doi.org/10.1017/S0954102022000475","url":null,"abstract":"Macroalgae cover up to 80% of the benthos along the western Antarctic Peninsula (WAP; Wiencke & Amsler 2012). One of the most common and widespread members of the understory community is the red macroalga Plocamium sp. (Heiser et al. 2020). It supports among the highest amphipod and gastropod densities and is protected from predation through highly diverse chemical defences (Heiser et al. 2020). Haplotypic diversity, based on the mitochondrial cox1 barcode, showed some evidence of geographical structure as well as correlation with specific chemical defences (Shilling et al. 2021). These coarse patterns of genetic diversity are insufficient to understand the processes structuring populations of Plocamium sp. along the WAP, necessitating the use of more polymorphic, nuclear loci, such as microsatellites. Microsatellites have enabled the empirical quantification of the relative rates of selfing (i.e. self-fertilization) vs outcrossing (e.g. Winn et al. 2011) and sexual vs asexual reproduction (e.g. Vallejo-Marín et al. 2010), but studies have been restricted largely to angiosperms or animals, with far fewer investigations in macroalgae (KruegerHadfield et al. 2021). Plocamium sp., like many macroalgae, has a haploid-diploid life cycle, with free-living diploid tetrasporophytes and free-living haploid gametophytes, which are morphologically indistinguishable unless they are reproductive (Fig. S1; Heiser et al. 2020). Meiosis occurs on the tetrasporophytes, resulting in the release of haploid tetraspores. Tetraspores germinate and develop into male and female gametophytes. Gametes are mitotically produced by the gametophytes, but, following fertilization, the zygote is retained on the female gametophyte, where the carposporophyte develops. Each diploid carpospore can germinate into a tetrasporophyte. In natural populations, many thalli are vegetative, rendering it difficult to distinguish the stages. This life cycle results in unique eco-evolutionary consequences that challenge traditional understanding and the utility of common proxies to describe patterns of reproductive system variation (Krueger-Hadfield et al. 2021). For example, Plocamium sp. has separate sexes, but this does not preclude selfing (intergametophytic selfing; see Klekowski 1969). Separate sexes, therefore, cannot be used as a proxy to deduce outcrossing in natural populations. Instead, we must use population genetic tools to empirically quantify the relative rates of selfing, outcrossing and asexual reproduction in natural populations. We developed microsatellites to quantify patterns of genetic diversity and gene flow in Plocamium sp. (Heiser 2022). We chose microsatellites over other approaches for several reasons: 1) microsatellites facilitate the iterative addition of new samples to a dataset, something that is not possible in most genotyping by sequencing (GBS) approaches to identify single nucleotide polymorphisms; 2) microsatellites are an appropriate tool when existing data","PeriodicalId":50972,"journal":{"name":"Antarctic Science","volume":"35 1","pages":"43 - 45"},"PeriodicalIF":1.6,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43499914","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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