Elementa-Science of the Anthropocene最新文献

{"title":"A microbial perspective on the local influence of Arctic rivers and estuaries on Hudson Bay (Canada)","authors":"Carlee Morency, L. Jacquemot, M. Potvin, C. Lovejoy","doi":"10.1525/elementa.2021.00009","DOIUrl":"https://doi.org/10.1525/elementa.2021.00009","url":null,"abstract":"A clear divide typically exists between freshwater and marine microbial communities, with transitional communities found in estuarine zones. The estuarine communities can derive from inflowing rivers and the sea via tidal mixing and incursions or be comprised of unique brackish species, depending on flow regimes and retention time within an estuary. Only a few studies have been carried out in the Arctic, where moderate salinities associated with the influence of seasonal ice melt could potentially favor marine microbes adapted to lower salinities in fresh-to-saltwater transition zones irrespective of river flows and tidal mixing. To test this idea, we examined early summer microbial communities in 2 western Hudson Bay (Canada) river-to-sea systems: the Churchill and Nelson river systems. Both rivers originate from the same headwaters, suggesting similar catchment conditions, but differ in geomorphology and hydroelectric diversions that induce very different flow and stratification regimes. Using amplicons of the V4 region of the 16S rRNA gene, we identified distinct riverine bacterial communities that were significantly different from the 2 associated estuaries and offshore communities. In the much smaller Churchill Estuary, the microbial community showed a marked influence of freshwater microbial species, along with marine influences. In contrast, in the larger high-flow Nelson River Estuary, riverine bacterioplankton were less evident in the estuary, where the marine signal was much stronger. The marine samples in both systems differed somewhat consistently with the phenology of the phytoplankton bloom in the Bay and tended to harbor distinct attached and free-living bacterial communities. Our results highlight the relevance of river flow and estuarine circulation on selection of bacterial species in estuaries, with ecological implications for food web functionality and biogeochemical cycles in the Anthropocene, where flow regimes would be affected by larger climatic variability.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overview of the MOSAiC expedition","authors":"M. Nicolaus, D. Perovich, G. Spreen, M. Granskog, Luisa von Albedyll, M. Angelopoulos, P. Anhaus, Stefanie Arndt, H. J. Belter, V. Bessonov, G. Birnbaum, J. Brauchle, Radiance Calmer, E. Cardellach, B. Cheng, D. Clemens-Sewall, R. Dadić, E. Damm, G. de Boer, O. Demir, K. Dethloff, D. Divine, A. Fong, S. Fons, M. Frey, Niels Fuchs, C. Gabarró, S. Gerland, H. Goessling, R. Gradinger, J. Haapala, C. Haas, Jonathan Hamilton, Henna-Reetta Hannula, S. Hendricks, A. Herber, C. Heuzé, M. Hoppmann, K. Høyland, M. Huntemann, J. Hutchings, B. Hwang, P. Itkin, H. Jacobi, Matthias Jaggi, Arttu Jutila, L. Kaleschke, C. Katlein, Nikolai Kolabutin, D. Krampe, S. Kristensen, T. Krumpen, N. Kurtz, A. Lampert, B. Lange, R. Lei, B. Light, F. Linhardt, G. Liston, B. Loose, Amy R. Macfarlane, Mallik S. Mahmud, I. Matero, S. Maus, A. Morgenstern, R. Naderpour, V. Nandan, Alexey Niubom, M. Oggier, N. Oppelt, F. Pätzold, Christophe Perron, Tomasz Petrovsky, R. Pirazzini, C. Polashenski, B. Rabe, Ian A. Raphael, J. Regnery, M. Rex","doi":"10.1525/elementa.2021.000046","DOIUrl":"https://doi.org/10.1525/elementa.2021.000046","url":null,"abstract":"Year-round observations of the physical snow and ice properties and processes that govern the ice pack evolution and its interaction with the atmosphere and the ocean were conducted during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition of the research vessel Polarstern in the Arctic Ocean from October 2019 to September 2020. This work was embedded into the interdisciplinary design of the 5 MOSAiC teams, studying the atmosphere, the sea ice, the ocean, the ecosystem, and biogeochemical processes. The overall aim of the snow and sea ice observations during MOSAiC was to characterize the physical properties of the snow and ice cover comprehensively in the central Arctic over an entire annual cycle. This objective was achieved by detailed observations of physical properties and of energy and mass balance of snow and ice. By studying snow and sea ice dynamics over nested spatial scales from centimeters to tens of kilometers, the variability across scales can be considered. On-ice observations of in situ and remote sensing properties of the different surface types over all seasons will help to improve numerical process and climate models and to establish and validate novel satellite remote sensing methods; the linkages to accompanying airborne measurements, satellite observations, and results of numerical models are discussed. We found large spatial variabilities of snow metamorphism and thermal regimes impacting sea ice growth. We conclude that the highly variable snow cover needs to be considered in more detail (in observations, remote sensing, and models) to better understand snow-related feedback processes. The ice pack revealed rapid transformations and motions along the drift in all seasons. The number of coupled ice–ocean interface processes observed in detail are expected to guide upcoming research with respect to the changing Arctic sea ice.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil surface flux measurements are a reliable means for assessing fugitive gas migration across soils and seasons","authors":"Mark Argento, F. Henderson, R. Lewis, D. Mallyon, D. Risk, N. Nickerson","doi":"10.1525/elementa.2021.00010","DOIUrl":"https://doi.org/10.1525/elementa.2021.00010","url":null,"abstract":"As oil and gas wells age and the number of wells drilled increases to meet demand, we may see more instances of fugitive soil gas migration (GM) and associated methane (CH4) emissions. Due to the immense spatiotemporal variability of soils and uncertainty in measurement practice, the detection and quantification of GM emissions is a challenge. Two common measurement techniques include the shallow in-soil gas concentration approach and soil surface flux measurements using flux chambers. In this numerical modeling study, both methods were compared to determine how soil texture, environmental conditions (water content, temperature), and CH4 leak rates into the soil profile influenced in-soil CH4 concentration and surface CH4 flux rates. We observed that in-soil CH4 concentration was strongly controlled by soil texture and environmental conditions, whereas surface CH4 flux rates were far less sensitive to those same parameters. Flux measurements were more useful for determining severity of the CH4 leak into the soil and allowed us to differentiate between leak and nonleak scenarios in soils with biological CH4 production which could complicate a GM assessment. We also evaluated field measurements of carbon dioxide from an enhanced oil recovery site to demonstrate how seasonal conditions can influence concentrations of trace gases in shallow soil. Based on our model results and supplemental field measurements, we propose that flux chamber measurements present a more reliable tool to assess the incidence and severity of fugitive GM.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An investigation of petrochemical emissions during KORUS-AQ: Ozone production, reactive nitrogen evolution, and aerosol production","authors":"Young Ro Lee, L. G. Huey, D. Tanner, M. Takeuchi, H. Qu, Xiaoxi Liu, N. Ng, J. Crawford, A. Fried, D. Richter, I. Simpson, D. Blake, N. Blake, S. Meinardi, Saewung Kim, G. Diskin, J. Digangi, Yonghoon Choi, S. Pusede, P. Wennberg, Michelle J. Kim, J. Crounse, A. Teng, R. Cohen, P. Romer, W. Brune, A. Wisthaler, T. Mikoviny, J. Jimenez, P. Campuzano‐Jost, B. Nault, A. Weinheimer, S. Hall, K. Ullmann","doi":"10.1525/elementa.2022.00079","DOIUrl":"https://doi.org/10.1525/elementa.2022.00079","url":null,"abstract":"Emissions and secondary photochemical products from the Daesan petrochemical complex (DPCC), on the west coast of South Korea, were measured from the NASA DC-8 research aircraft during the Korea-United States Air Quality campaign in 2016. The chemical evolution of petrochemical emissions was examined utilizing near-source and downwind plume transects. Small alkenes, such as ethene (C2H4), propene (C3H6), and 1,3-butadiene (C4H6), dominated the hydroxyl (OH) radical reactivity near the source region. The oxidation of these alkenes in the petrochemical plumes led to efficient conversion of nitrogen oxides (NOx) to nitric acid (HNO3), peroxycarboxylic nitric anhydrides (PANs), and alkyl nitrates (ANs), where the sum of the speciated reactive nitrogen contributes more than 80% of NOy within a few hours. Large enhancements of short-lived NOx oxidation products, such as hydroxy nitrates (HNs) and peroxyacrylic nitric anhydride, were observed, in conjunction with high ozone levels of up to 250 ppb, which are attributed to oxidation of alkenes such as 1,3-butadiene. Instantaneous ozone production rates, P(O3), near and downwind of the DPCC ranged from 9 to 24 ppb h−1, which were higher than those over Seoul. Ozone production efficiencies ranged from 6 to 10 downwind of the DPCC and were lower than 10 over Seoul. The contributions of alkenes to the instantaneous secondary organic aerosol (SOA) production rate, P(SOA), were estimated to be comparable to those of more common SOA precursors such as aromatics at intermediate distances from the DPCC. A model case study constrained to an extensive set of observations provided a diagnostic of petrochemical plume chemistry. The simulated plume chemistry reproduced the observed evolution of ozone and short-lived reactive nitrogen compounds, such as PANs and HNs as well as the rate and efficiency of ozone production. The simulated peroxy nitrates (PNs) budget included large contributions (approximately 30%) from unmeasured PNs including peroxyhydroxyacetic nitric anhydride and peroxybenzoic nitric anhydride. The large, predicted levels of these PAN compounds suggest their potential importance in chemical evolution of petrochemical plumes. One unique feature of the DPCC plumes is the substantial contribution of 1,3-butadiene to ozone and potentially SOA production. This work suggests that reductions in small alkene, especially 1,3-butadiene, emissions from the DPCC should be a priority for reducing downwind ozone.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66944380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterioplankton response to physical stratification following deep convection","authors":"Nicholas Baetge, Luis M. Bolaños, A. Penna, P. Gaube, Shuting Liu, Keri Opalk, Jason R. Graff, S. Giovannoni, M. Behrenfeld, C. Carlson","doi":"10.1525/elementa.2021.00078","DOIUrl":"https://doi.org/10.1525/elementa.2021.00078","url":null,"abstract":"Dissolved organic carbon (DOC) produced by primary production in the sunlit ocean can be physically transported to the mesopelagic zone. The majority of DOC exported to this zone is remineralized by heterotrophic microbes over a range of timescales. Capturing a deep convective mixing event is rare, as is observing how microbes respond in situ to the exported DOC. Here, we report ship and Argo float observations from hydrostation North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) 2 Station 4 (N2S4; 47.46°N, 38.72°W), a retentive anticyclonic eddy in the subtropical region of the western North Atlantic. Changes in biogeochemistry and bacterioplankton responses were tracked as the water column mixed to approximately 230 m and restratified over the subsequent 3 days. Over this period, rapid changes in bacterioplankton production (BP) and cell abundance were observed throughout the water column. BP increased by 91% in the euphotic zone (0–100 m) and 55% in the upper mesopelagic zone (100–200 m), corresponding to 33% and 103% increases in cell abundance, respectively. Within the upper mesopelagic, BP upon the occupation of N2S4 (20 ± 4.7 nmol C L–1 d–1) was significantly greater than the average upper mesopelagic BP rate (2.0 ± 1.6 nmol C L–1 h–1) at other stations that had been stratified for longer periods of time. BP continued to increase to 31 ± 3.0 nmol C L–1 d–1 over the 3-day occupation of N2S4. The rapid changes in BP in the upper mesopelagic did not coincide with rapid changes in community composition, but the taxa that increased in their relative contribution included those typically observed in the epipelagic zone. We interpret the subtle but significant community structure dynamics at N2S4 to reflect how injection of labile organic matter into the upper mesopelagic zone by physical mixing supports continued growth of euphotic zone-associated bacterioplankton lineages on a timescale of days.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66941770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity and biogeography of planktonic diatoms in Svalbard fjords: The role of dispersal and Arctic endemism in phytoplankton community structuring","authors":"L. Šupraha, K. Klemm, Sandra Gran-Stadniczeñko, C. Hörstmann, D. Vaulot, B. Edvardsen, U. John","doi":"10.1525/elementa.2021.00117","DOIUrl":"https://doi.org/10.1525/elementa.2021.00117","url":null,"abstract":"Understanding the processes that shape the community structure of Arctic phytoplankton is crucial for predicting responses of Arctic ecosystems to the ongoing ocean warming. In particular, little is known about the importance of phytoplankton dispersal by the North Atlantic Current and the prevalence and maintenance of Arctic endemism. We investigated the diversity and biogeography of diatoms from five Svalbard fjords and the Hausgarten observatory (Fram Strait) by combining diatom cultivation and 18S rRNA gene metabarcoding. In total, 50 diatom strains were isolated from the area during the HE492 cruise in August 2017. The strains were identified taxonomically using molecular and morphological approaches, and their biogeographic distribution was mapped using the local metabarcoding dataset and a global compilation of published metabarcoding datasets. Biogeographic analysis was also conducted for the locally most abundant diatom metabarcoding amplicon sequence variants. The biogeographic analyses demonstrated that Arctic diatoms exhibit three general biogeographic distribution types: Arctic, Arctic-temperate, and cosmopolitan. At Hausgarten and in outer Isfjorden on the west coast of Svalbard, the communities were dominated by genotypes with Arctic-temperate and cosmopolitan distribution. Diatom communities in nearby Van Mijenfjorden, inner Isfjorden and Kongsfjorden were dominated by genotypes with Arctic-temperate distribution, and cosmopolitan species were less abundant. The genotypes endemic to the Arctic had lower abundance on the west coast of Svalbard. The two northernmost fjords (Woodfjorden and Wijdefjorden) had a higher abundance of genotypes endemic to the Arctic. Our results demonstrate that the diatom communities in the Svalbard area consist of genotypes endemic to the Arctic, and genotypes with broader biogeographic distribution, all of which are further structured by local environmental gradients. Finer biogeographic patterns observed within Arctic-temperate and cosmopolitan genotypes suggest that certain genotypes can be used as indicators of increasing influence of Atlantic waters on the phytoplankton community structure in the Svalbard area.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66942770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of oyster aquaculture on the estuarine carbonate system","authors":"Catherine M. Liberti, M. Gray, L. Mayer, J. Testa, Wei Liu, D. Brady","doi":"10.1525/elementa.2020.00057","DOIUrl":"https://doi.org/10.1525/elementa.2020.00057","url":null,"abstract":"Many studies have examined the vulnerability of calcifying organisms, such as the eastern oyster (Crassostrea virginica), to externally forced ocean acidification, but the opposite interaction whereby oysters alter their local carbonate conditions has received far less attention. We present an exploratory model for isolating the impact that net calcification and respiration of aquacultured eastern oysters can have on calcite and aragonite saturation states, in the context of varying temperature, ocean-estuary mixing, and air-sea gas exchange. We apply the model to the Damariscotta River Estuary in Maine which has experienced rapid expansion of oyster aquaculture in the last decade. Our model uses oyster shell growth over the summer season and a previously derived relationship between net calcification and respiration to quantify impacts of net oyster calcification and gross metabolism on carbonate saturation states in open tidal waters. Under 2018 industry size and climate conditions, we estimate that oysters can lower carbonate saturation states by up to 5% (i.e., 0.17 and 0.11 units on calcite and aragonite saturation states, respectively) per day in late summer, with an average of 3% over the growing season. Perturbations from temperature and air-sea exchange are similar in magnitude. Under 2050 climate conditions and 2018 industry size, calcite saturation state will decrease by up to an additional 0.54 units. If the industry expands 3-fold by 2050, the calcite and aragonite saturation states may decrease by 0.73 and 0.47 units, respectively, on average for the latter half of the growing season when compared to 2018 climate conditions and industry size. Collectively, our results indicate that dense aggregations of oysters can have a significant role on estuarine carbonate chemistry.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66938284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights on sources and formation mechanisms of liquid-bearing clouds over MOSAiC examined from a Lagrangian framework","authors":"I. Silber, M. Shupe","doi":"10.1525/elementa.2021.000071","DOIUrl":"https://doi.org/10.1525/elementa.2021.000071","url":null,"abstract":"Understanding Arctic stratiform liquid-bearing cloud life cycles and properly representing these life cycles in models is crucial for evaluations of cloud feedbacks as well as the faithfulness of climate projections for this rapidly warming region. Examination of cloud life cycles typically requires analyses of cloud evolution and origins on short time scales, on the order of hours to several days. Measurements from the recent Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provide a unique view of the current state of the central Arctic over an annual cycle. Here, we use the MOSAiC radiosonde measurements to detect liquid-bearing cloud layers over full atmospheric columns and to examine the cloud-generating air masses’ properties. We perform 5-day (120 h) back-trajectory calculations for every detected cloud and cluster them using a unique set of variables extracted from these trajectories informed by ERA5 reanalysis data. This clustering method enables us to separate between the air mass source regions such as ice-covered Arctic and midlatitude open water. We find that moisture intrusions into the central Arctic typically result in multilayer liquid-bearing cloud structures and that more than half of multilayer profiles include overlying liquid-bearing clouds originating in different types of air masses. Finally, we conclude that Arctic cloud formation via prolonged radiative cooling of elevated stable subsaturated air masses circulating over the Arctic can occur frequently (up to 20% of detected clouds in the sounding data set) and may lead to a significant impact of ensuing clouds on the surface energy budget, including net surface warming in some cases.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alignment of optical backscatter measurements from the EXPORTS Northeast Pacific Field Deployment","authors":"Z. Erickson, I. Cetinić, Xiaodong Zhang, E. Boss, P. J. Werdell, S. Freeman, Lianbo Hu, Craig M. Lee, M. Omand, M. Perry","doi":"10.1525/elementa.2021.00021","DOIUrl":"https://doi.org/10.1525/elementa.2021.00021","url":null,"abstract":"Backscattering of light is commonly measured by ocean observing systems, including ships and autonomous platforms, and is used as a proxy for the concentration of water column constituents such as phytoplankton and particulate carbon. Multiple on-going projects involve large numbers of independent measurements of backscatter, as well as other biologically relevant parameters, to understand how biology is changing in time and space throughout the global ocean. Rarely are there sufficient measurements to test how well these instruments are inter-calibrated in real-world deployment conditions. This paper develops a procedure to align multiple independently calibrated backscatter instruments to each other using nearby profiling casts and applies this method to nine instruments deployed during a recent field campaign in the North Pacific during August–September of 2018. This process revealed several incorrect calibrations; post-alignment, all nine instruments aligned extremely well with each other. We also tested an alignment to a deep-water reference and found that this method is generally sufficient but has significant limitations; this procedure lacks the ability to correct instruments measuring only shallow profiles and can only account for additive offsets, not multiplicative changes. These findings highlight the utility of process studies involving several independent measurements of similar parameters in the same area.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the phenology and seeding potential of sea-ice microalgal species","authors":"M. V. van Leeuwe, M. Fenton, Emily Davey, Janne-Markus Rintala, E. Jones, M. Meredith, J. Stefels","doi":"10.1525/elementa.2021.00029","DOIUrl":"https://doi.org/10.1525/elementa.2021.00029","url":null,"abstract":"Sea ice is an important habitat for a wide variety of microalgal species. Depending on the species composition, sea ice can be a seeding source for pelagic phytoplankton blooms after ice melt in spring. Sea-ice algal communities were studied over 2 full winter seasons in 2014 and 2016 at Rothera Research Station, situated at the Western Antarctic Peninsula (WAP). Algal pigment patterns and microscopic observations were combined with photophysiological studies based on fluorescence analyses to monitor and explain the phenology of ice-algal species. Clear patterns in species succession were identified. Young sea ice contained a mixture of algal species including dinoflagellates, cryptophytes and diatoms like Chaetoceros spp. and Fragillariopsis spp. In winter, severe environmental conditions resulted in a decline in species diversity and selection towards heterotrophy. Pennate diatoms like Amphiprora kufferathii and Berkeleya adeliensis were the first to dominate the nutrient-enriched bottom-ice layers in early spring. The bottom communities exhibited a remarkably stable value for the photoadaptation parameter, Ek, of circa 25 µmol photons m–2 s–1. Whereas pennate diatoms were most abundant in spring ice, the initial seeding event linked to ice melt was associated with flagellate species. Haptophyte species like Phaeocystis antarctica and prymnesiophytes like Pyramimonas spp. best sustained the transition from sea ice to seawater. Comparison with previous studies shows that the seeding patterns observed in Ryder Bay were characteristic over the wider sea-ice domain, Arctic and Antarctic. Over the course of this century, the WAP is predicted to experience continuing thinning and decline in sea-ice cover. For the near future, we expect that especially microalgal communities of haptophytes and chlorophytes will benefit from the changes, with yet unknown implications for carbon fluxes and higher trophic levels.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66940924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}