[{"awards": "2224760 Gooseff, Michael", "bounds_geometry": "POINT(162.87 -77)", "dataset_titles": "EDI Data Portal: McMurdo Dry Valleys LTER", "datasets": [{"dataset_uid": "200379", "doi": "", "keywords": null, "people": null, "repository": "Environmental Data Initiative (EDI)", "science_program": null, "title": "EDI Data Portal: McMurdo Dry Valleys LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM"}], "date_created": "Tue, 14 Nov 2023 00:00:00 GMT", "description": "In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world\u0027s critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education \u0026 Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6.", "east": 162.87, "geometry": "POINT(162.87 -77)", "instruments": null, "is_usap_dc": true, "keywords": "COMMUNITY DYNAMICS; ABLATION ZONES/ACCUMULATION ZONES; SOIL TEMPERATURE; DIATOMS; FIELD INVESTIGATION; PERMANENT LAND SITES; BUOYS; GROUND-BASED OBSERVATIONS; SEDIMENTS; SNOW WATER EQUIVALENT; SPECIES/POPULATION INTERACTIONS; WATER-BASED PLATFORMS; FIXED OBSERVATION STATIONS; VIRUSES; PHYTOPLANKTON; ACTIVE LAYER; FIELD SURVEYS; RADIO TRANSMITTERS; DATA COLLECTIONS; ECOLOGICAL DYNAMICS; LANDSCAPE; GROUND WATER; SNOW/ICE CHEMISTRY; LAND-BASED PLATFORMS; ANIMALS/INVERTEBRATES; ECOSYSTEM FUNCTIONS; HUMIDITY; GEOCHEMISTRY; SURFACE WINDS; RIVERS/STREAM; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; SNOW; LAND RECORDS; ATMOSPHERIC PRESSURE; SURFACE TEMPERATURE; ATMOSPHERIC RADIATION; BACTERIA/ARCHAEA; AIR TEMPERATURE; GLACIERS; SNOW/ICE TEMPERATURE; SOIL CHEMISTRY; METEOROLOGICAL STATIONS; WATER QUALITY/WATER CHEMISTRY; TERRESTRIAL ECOSYSTEMS; MOORED; PROTISTS; STREAMFLOW STATION; Dry Valleys; LAKE/POND; LAKE ICE; SNOW DEPTH; AQUATIC ECOSYSTEMS; SNOW DENSITY; FIELD SITES", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gooseff, Michael N.; Adams, Byron; Barrett, John; Diaz, Melisa A.; Doran, Peter; Dugan, Hilary A.; Mackey, Tyler; Morgan-Kiss, Rachael; Salvatore, Mark; Takacs-Vesbach, Cristina; Zeglin, Lydia H.", "platforms": "LAND-BASED PLATFORMS; LAND-BASED PLATFORMS \u003e FIELD SITES; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e RADIO TRANSMITTERS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e STREAMFLOW STATION; WATER-BASED PLATFORMS; WATER-BASED PLATFORMS \u003e BUOYS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "Environmental Data Initiative (EDI)", "repositories": "Environmental Data Initiative (EDI)", "science_programs": "LTER", "south": -77.0, "title": "LTER: MCM6 - The Roles of Legacy and Ecological Connectivity in a Polar Desert Ecosystem", "uid": "p0010440", "west": 162.87}, {"awards": "1744767 Sanders, Robert", "bounds_geometry": "POLYGON((-68 -64,-67.4 -64,-66.8 -64,-66.2 -64,-65.6 -64,-65 -64,-64.4 -64,-63.8 -64,-63.2 -64,-62.6 -64,-62 -64,-62 -64.5,-62 -65,-62 -65.5,-62 -66,-62 -66.5,-62 -67,-62 -67.5,-62 -68,-62 -68.5,-62 -69,-62.6 -69,-63.2 -69,-63.8 -69,-64.4 -69,-65 -69,-65.6 -69,-66.2 -69,-66.8 -69,-67.4 -69,-68 -69,-68 -68.5,-68 -68,-68 -67.5,-68 -67,-68 -66.5,-68 -66,-68 -65.5,-68 -65,-68 -64.5,-68 -64))", "dataset_titles": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.; Expedition Data of NBP1910; Expedition Data of NBP 2205; LMG1904 expedition data; NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "datasets": [{"dataset_uid": "200147", "doi": "10.7284/908260", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1904 expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1904"}, {"dataset_uid": "200320", "doi": "10.6084/m9.figshare.19514110.v3", "keywords": null, "people": null, "repository": "Figshare", "science_program": null, "title": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.", "url": "https://doi.org/10.6084/m9.figshare.19514110.v3"}, {"dataset_uid": "200325", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1910", "url": "https://www.rvdata.us/search/cruise/NBP1910"}, {"dataset_uid": "200365", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=PRJNA807326"}, {"dataset_uid": "200366", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP 2205", "url": "https://www.rvdata.us/search/cruise/NBP2205"}], "date_created": "Wed, 27 Jul 2022 00:00:00 GMT", "description": "Traditional models of oceanic food chains have consisted of photosynthetic algae (phytoplankton) being ingested by small animals (zooplankton), which were ingested by larger animals (fish). These traditional models changed as new methods allowed recognition of the importance of bacteria and other non-photosynthetic protozoa in more complex food webs. More recently, the wide-spread existence of mixotrophs (organisms that can both photosynthesize and ingest food particles) and their importance as microbial predators has been recognized in many oceanographic areas. In the Southern Ocean, the only two surveys of mixotrophs have suggested that there may be seasonal differences in their importance as predators. During the long polar night (winter), the ability of mixotrophs to ingest particulate food may aid in their survival thus ensuring a sufficient population in spring to support a phytoplankton bloom once photosynthesis rates can increase. Thus mixotrophs may provide a critical early food source upon which zooplankton and larger animals depend on for growth and reproduction. This project will advance understanding of mixotroph diversity and their ecological impact within the Southern Ocean microbial food web. Specifically, efforts will be focused on mixotrophy in the western Antarctica peninsula region during the austral spring and autumn when there are likely to be changes in the relative importance of photosynthesis and ingestion to mixotrophs. The project will provide research opportunities for undergraduate and graduate students and a post-doctoral researcher. There will be real-time outreach from the Southern Ocean to the public via blogs and interviews, and to high school art students through an established program that blends science and art education. Despite traditional views of protists as either \"phototrophic\" or \"heterotrophic,\" there are many photosynthetic protists that consume prey (mixotrophy). Mixotrophy is a widespread phenomenon in aquatic systems and phytoplankton groups with known mixotrophic species, notably chrysophytes, cryptophytes, prymnesiophytes, prasinophytes and dinoflagellates, are present and often abundant in Antarctic waters. However, in the Southern Ocean, the presence of mixotrophic phytoflagellates has been surveyed only twice prior to this project: in the Ross Sea during Austral spring 2008 and summer 2011. The primary goals of the project are to gain better understanding of mixotroph diversity and their ecological impact with respect to the Southern Ocean microbial food web. The contribution of mixotrophs to primary production and bacterial consumption is likely linked to the taxonomic composition of the community and the abundance of particular species. Abundances of novel mixotrophic species will be evaluated via qPCR, which will be coupled with assessments of rates of feeding and photosynthesis with the goal of describing how active mixotrophs direct the movement of carbon through food webs. These experiments will help the determination of how viable and widespread mixotrophy is as a nutritional strategy in polar waters and give direct information on the currently unknown diversity of mixotrophic taxa under different environmental conditions occurring in austral spring and autumn. Furthermore, the methods will simultaneously yield information on the whole communities of protists - mixotrophic, phototrophic and heterotrophic. In addition, a method to examine aspects of the taxonomic and functional diversities of the bacterivorous/mixotrophic community will be employed. A thymidine analog (BrdU) will be used to label DNA of eukaryotes feeding on bacteria. The BrdU-labeled eukaryotic DNA will be isolated using immunoprecipitation. High-throughput sequencing of the labeled DNA (bacterivores) versus unlabeled community DNA will determine the diversity of bacterivorous mixotrophs relative to other microeukaryotes. Flow cytometric sorting based on chlorophyll to focus on mixotrophic species. These approaches will elucidate a gap in current knowledge of the influence of microbial interactions in the Southern Ocean under different conditions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-65 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; PLANKTON; COASTAL", "locations": "Antarctic Peninsula", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sanders, Robert; Gast, Rebecca; Jeffrey, Wade H.", "platforms": null, "repo": "R2R", "repositories": "Figshare; NCBI; R2R", "science_programs": null, "south": -69.0, "title": "Collaborative Research: Diversity and ecological impacts of Antarctic mixotrophic phytoplankton", "uid": "p0010357", "west": -68.0}, {"awards": "1947040 Postlethwait, John", "bounds_geometry": "POLYGON((-65.3 -63.3,-65 -63.3,-64.7 -63.3,-64.4 -63.3,-64.1 -63.3,-63.8 -63.3,-63.5 -63.3,-63.2 -63.3,-62.9 -63.3,-62.6 -63.3,-62.3 -63.3,-62.3 -63.47,-62.3 -63.64,-62.3 -63.81,-62.3 -63.98,-62.3 -64.15,-62.3 -64.32,-62.3 -64.49,-62.3 -64.66,-62.3 -64.83,-62.3 -65,-62.6 -65,-62.9 -65,-63.2 -65,-63.5 -65,-63.8 -65,-64.1 -65,-64.4 -65,-64.7 -65,-65 -65,-65.3 -65,-65.3 -64.83,-65.3 -64.66,-65.3 -64.49,-65.3 -64.32,-65.3 -64.15,-65.3 -63.98,-65.3 -63.81,-65.3 -63.64,-65.3 -63.47,-65.3 -63.3))", "dataset_titles": "18 SSU rDNA type sequences for Notoxcellia coronata (nov. sp.); 18 SSU rDNA type sequences for Notoxcellia picta (nov. sp.); Fish pictures and skin pathology of X-cell infection in Trematomus scotti.; Histopathology of X-cell xenomas in Trematomus scotti and Nototheniops larseni.; In situ hybridization of X-cell and host fish 18S SSU rRNA in alternate sections of tumor xenomas.; Metagenomic analysis of apparently healthy and tumor samples using Kaiju software ; microMRI analyses of Trematomus scotti Tsco_18_08 with X-cell xenomas; Morphological and pathological data of Trematomus scotti specimens captured on May 30th, 2018 in Andvord Bay.; Nomenclatural Act for the genus Notoxcellia; Nomenclatural Act for the species Notoxcellia coronata; Nomenclatural Act for the species Notoxcellia picta; Phylogenetic Analysis of Notoxcellia species.; Raw Illumina sequencing reads from skin tumors and visually healthy skins from Trematomus scotti and Nototheniops larseni; Temperature profiles at five fishing locations on the West Antarctic Peninsula during austral fall 2018.; Trematomus scotti with X-cell xenomas", "datasets": [{"dataset_uid": "601538", "doi": "10.15784/601538", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Notoxcellia Coronata; Notoxcellia Picta; Perkinsozoa; Xcellidae", "people": "Lauridsen, Henrik; Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "microMRI analyses of Trematomus scotti Tsco_18_08 with X-cell xenomas", "url": "https://www.usap-dc.org/view/dataset/601538"}, {"dataset_uid": "200384", "doi": "", "keywords": null, "people": null, "repository": "ZooBank", "science_program": null, "title": "Nomenclatural Act for the species Notoxcellia picta", "url": "https://zoobank.org/NomenclaturalActs/31062dd2-7202-47fa-86e0-7be5c55ac0e2"}, {"dataset_uid": "200383", "doi": "", "keywords": null, "people": null, "repository": "ZooBank", "science_program": null, "title": "Nomenclatural Act for the species Notoxcellia coronata", "url": "https://zoobank.org/NomenclaturalActs/194d91b2-e268-4238-89e2-385819f2c35b"}, {"dataset_uid": "200382", "doi": "", "keywords": null, "people": null, "repository": "ZooBank", "science_program": null, "title": "Nomenclatural Act for the genus Notoxcellia", "url": "https://zoobank.org/NomenclaturalActs/5cf9609e-0111-4386-8518-bd50b5bdde0e"}, {"dataset_uid": "601539", "doi": "10.15784/601539", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Notoxcellia Coronata; Notoxcellia Picta; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "In situ hybridization of X-cell and host fish 18S SSU rRNA in alternate sections of tumor xenomas.", "url": "https://www.usap-dc.org/view/dataset/601539"}, {"dataset_uid": "601537", "doi": "10.15784/601537", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Notoxcellia Coronata; Notoxcellia Picta; Perkinsozoa; Xcellidae", "people": "Fontenele, Rafaela S. ; Varsani, Arvind; Kraberger, Simona ; Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Metagenomic analysis of apparently healthy and tumor samples using Kaiju software ", "url": "https://www.usap-dc.org/view/dataset/601537"}, {"dataset_uid": "601494", "doi": "10.15784/601494", "keywords": "Andvord Bay; Antarctica; Fish", "people": "Postlethwait, John; Desvignes, Thomas; Le Francois, Nathalie; Lauridsen, Henrik", "repository": "USAP-DC", "science_program": null, "title": "Morphological and pathological data of Trematomus scotti specimens captured on May 30th, 2018 in Andvord Bay.", "url": "https://www.usap-dc.org/view/dataset/601494"}, {"dataset_uid": "601495", "doi": "10.15784/601495", "keywords": "Antarctica; Antarctic Peninsula", "people": "Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Temperature profiles at five fishing locations on the West Antarctic Peninsula during austral fall 2018.", "url": "https://www.usap-dc.org/view/dataset/601495"}, {"dataset_uid": "601496", "doi": "10.15784/601496", "keywords": "Andvord Bay; Antarctica; Fish", "people": "Postlethwait, John; Desvignes, Thomas; Lauridsen, Henrik", "repository": "USAP-DC", "science_program": null, "title": "Fish pictures and skin pathology of X-cell infection in Trematomus scotti.", "url": "https://www.usap-dc.org/view/dataset/601496"}, {"dataset_uid": "601536", "doi": "10.15784/601536", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Notoxcellia Coronata; Notoxcellia Picta; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Kent, Michael L. ; Murray, Katrina N. ; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Histopathology of X-cell xenomas in Trematomus scotti and Nototheniops larseni.", "url": "https://www.usap-dc.org/view/dataset/601536"}, {"dataset_uid": "601501", "doi": "10.15784/601501", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Biota; Notoxcellia Coronata; Notoxcellia Picta; Oceans; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Varsani, Arvind; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Phylogenetic Analysis of Notoxcellia species.", "url": "https://www.usap-dc.org/view/dataset/601501"}, {"dataset_uid": "200277", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "Raw Illumina sequencing reads from skin tumors and visually healthy skins from Trematomus scotti and Nototheniops larseni", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA789574"}, {"dataset_uid": "200262", "doi": "", "keywords": null, "people": null, "repository": "MorphoSource", "science_program": null, "title": "Trematomus scotti with X-cell xenomas", "url": "https://www.morphosource.org/projects/000405843?locale=en"}, {"dataset_uid": "200276", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "18 SSU rDNA type sequences for Notoxcellia picta (nov. sp.)", "url": "https://www.ncbi.nlm.nih.gov/nuccore/OL630145"}, {"dataset_uid": "200275", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "18 SSU rDNA type sequences for Notoxcellia coronata (nov. sp.)", "url": "https://www.ncbi.nlm.nih.gov/nuccore/OL630144"}], "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Overview:\r\nAntarctic biota face increasing stressors from warming oceans. A key question is: What will be the effect of warming waters on Antarctic biota? A gap in our knowledge is the identify of early harbingers of new stressors. In our recent field season, we unexpectedly discovered pink, wart-like neoplasms in Antarctic notothenioid fish, including Trematomus scotti (crowned notothen) and Nototheniops larseni (painted notothen). Neoplasms affected about 30% of T. scotti collected in Andvord Bay on the West Antarctic Peninsula and covered 10 to 30% of the bodies of affected individuals, usually in one contiguous patch. We collected samples from affected and apparently unaffected controls. We could not find evidence of any similar outbreak. Our overall goal is to learn the biological origins of this neoplasm and how it affects cellular function and organismal physiology. \r\nIntellectual Merit:\r\nAim 1: Pathogenic agents. Aim 1a: To test the hypothesis that a virus causes the neoplasm. Methods involve isolating and sequencing viral nucleic acids from neoplasms and from unaffected skin and comparing sequences to known viruses. Aim 1b: To test the hypothesis that neoplasms are hosts to parasites not present in healthy skin. Methods include tissue sections and DNA sequencing to find evidence of parasitic organisms. Significance: achieving Aim 1 will narrow down possible etiological agents. An untested possibility is that environmental contaminants cause the condition; exploring that hypothesis would require further sampling outside the limits of an EAGER proposal.\r\nAim 2: Cell-level pathology. Aim 2a: To test the hypothesis that the histopathology of the neoplasms is similar to other known skin neoplasias; alternatively, it might be a previously unknown type of neoplasia. Methods involve the examination of histological sections to identify pathology-specific characters. Aim 2b: To find effects of neoplasms on cell function. Methods involve performing whole-genome transcriptomics of affected and normal skin by RNA-seq and aligning reads to a T. scotti reference genome. Significance: achieving Aim 2 will define the cell biology and gene-expression phenotypes of the neoplasia, thus suggesting mechanisms that cause it.\r\n[Note: NSF deleted funds specifically to achieve the Aim 3, which nevertheless appears here to represent the original proposal.] Aim 3: Organismal pathology. Aim 3a: To test the hypothesis that the neoplasm has adverse effects on growth and physiology. Methods are to perform morphometrics in fish with neoplasms compared to age-matched controls from otolith studies. Aim 3b: To test the hypothesis that the neoplasia affects reproductive traits. Methods compare reproductive effort in affected and unaffected individuals. Significance: if the neoplasia has little consequences on growth and reproduction, our worry about its spread will be lessened, but if it is harmful, then Antarctic ecology, which largely depends on notothenioid fish, might be in danger.\r\nAchieving Aims 1-3 will advance knowledge by identifying the causes of a neoplasia outbreak in Antarctic fish. Work is potentially transformative because it might represent an early sign of Antarctic fish responses to the stress of global climate change. Proposed work would be the first to investigate a neoplasia outbreak in Antarctic fish. We will assess the project\u2019s success by whether we identify a causative agent and its effects on physiology.\r\nBroader Impacts:\r\nAim 4: Publicizing the neoplasia. We aim to raise awareness of the outbreak and publicize its distinct diagnostic features, including assays to detect it, by contributing to groups that track Antarctic ecosystems. \r\nAim 5: Inclusion. We will involve underrepresented groups in scientific research with authentic research experiences.\r\nAchieving Aims 4 and 5 will benefit society because they will disseminate to scientific and lay communities a potential early-warning system for the effects of an apparently new neoplasia affecting, at least locally, a large proportion of a fish population. Dissemination will stir research to determine whether this neoplasia outbreak is an isolated event or is becoming a general phenomenon, and thus a concern for Antarctic ecosystems. Proposed research will enhance research infrastructure by providing tools to identify the neoplasia. Finally, the project will broaden access to research careers by exposing underserved high school students and undergraduates to an exciting live research project.\r\n", "east": -62.3, "geometry": "POINT(-63.8 -64.15)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Andvord Bay; Amd/Us; PROTISTS; BENTHIC; FISH; Dallmann Bay; USAP-DC; NSF/USA; AMD", "locations": "Andvord Bay; Dallmann Bay", "north": -63.3, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Postlethwait, John; Varsani, Arvind; Desvignes, Thomas", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "GenBank; MorphoSource; NCBI SRA; USAP-DC; ZooBank", "science_programs": null, "south": -65.0, "title": "EAGER: Origin and Physiological Consequences of a Neoplasm Outbreak in Antarctic Fish ", "uid": "p0010221", "west": -65.3}, {"awards": "1846837 Bowman, Jeff", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "The coastal Antarctic is undergoing great environmental change. Physical changes in the environment, such as altered sea ice duration and extent, have a direct impact on the phytoplankton and bacteria species which form the base of the marine foodweb. Photosynthetic phytoplankton are the ocean\u0027s primary producers, transforming (fixing) CO2 into organic carbon molecules and providing a source of food for zooplankton and larger predators. When phytoplankton are consumed by zooplankton, or killed by viral attack, they release large amounts of organic carbon and nutrients into the environment. Heterotrophic bacteria must eat other things, and function as \"master recyclers\", consuming these materials and converting them to bacterial biomass which can feed larger organisms such as protists. Some protists are heterotrophs, but others are mixotrophs, able to grow by photosynthesis or heterotrophy. Previous work suggests that by killing and eating bacteria, protists and viruses may regulate bacterial populations, but how these processes are regulated in Antarctic waters is poorly understood. This project will use experiments to determine the rate at which Antarctic protists consume bacteria, and field studies to identify the major bacterial taxa involved in carbon uptake and recycling. In addition, this project will use new sequencing technology to obtain completed genomes for many Antarctic marine bacteria. To place this work in an ecosystem context this project will use microbial diversity data to inform rates associated with key microbial processes within the PALMER ecosystem model.\r\n\r\nThis project addresses critical unknowns regarding the ecological role of heterotrophic marine bacteria in the coastal Antarctic and the top-down controls on bacterial populations. Previous work suggests that at certain times of the year grazing by heterotrophic and mixotrophic protists may meet or exceed bacterial production rates. Similarly, in more temperate waters bacteriophages (viruses) are thought to contribute significantly to bacterial mortality during the spring and summer. These different top-down controls have implications for carbon flow through the marine foodweb, because protists are grazed more efficiently by higher trophic levels than are bacteria. This project uses a combination of grazing experiments and field observations to assess the temporal dynamics of mortality due to temperate bacteriophage and protists. Although many heterotrophic bacterial strains observed in the coastal Antarctic are taxonomically similar to strains from other regions, recent work suggest that they are phylogenetically and genetically distinct. To better understand the ecological function and evolutionary trajectories of key Antarctic marine bacteria, their genomes will be isolated and sequenced. Then, these genomes will be used to improve the predictions of the paprica metabolic inference pipeline, and our understanding of the relationship between heterotrophic bacteria and their major predators in the Antarctic marine environment. Finally, the research team will modify the Regional Test-Bed Model model to enable microbial diversity data to be used to optimize the starting conditions of key parameters, and to constrain the model\u0027s data assimilation methods.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Magmatic Volatiles; BACTERIA/ARCHAEA; VIRUSES; USA/NSF; Palmer Station; ECOSYSTEM FUNCTIONS; COMMUNITY DYNAMICS; LABORATORY; Amd/Us; PROTISTS; AMD; USAP-DC", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bowman, Jeff; Connors, Elizabeth", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Understanding microbial heterotrophic processes in coastal Antarctic waters", "uid": "p0010201", "west": null}, {"awards": "1642570 Thurber, Andrew", "bounds_geometry": "POINT(166.666 -77.8)", "dataset_titles": "Microbial community composition of the Cinder Cones Cold Seep", "datasets": [{"dataset_uid": "200035", "doi": "DOI:10.1575/1912/bco-dmo.756997.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Microbial community composition of the Cinder Cones Cold Seep", "url": "https://www.bco-dmo.org/dataset/756997"}], "date_created": "Fri, 24 May 2019 00:00:00 GMT", "description": "Methane is a potent greenhouse gas that is naturally emitted into the oceans by geologic seeps and microbial production. Based on studies of persistent deep-sea seeps at mid- and northern latitudes, researchers have learned that bacteria and archaea can create a \"sediment filter\" that oxidizes methane prior to its release. Antarctica is thought to contain large reservoirs of organic carbon buried beneath its ice which could a quantity of methane equivalent to all of the permafrost in the Arctic and yet we know almost nothing about the methane oxidizing microbes in this region. How these microbial communities develop and potentially respond to fluctuations in methane levels is an under-explored avenue of research. A bacterial mat was recently discovered at 78 degrees south, suggesting the possible presence of a methane seep, and associated microbial communities. This project will explore this environment in detail to assess the levels and origin of methane, and the nature of the microbial ecosystem present. \u003cbr/\u003e \u003cbr/\u003eAn expansive bacterial mat appeared and/or was discovered at 78 degrees south in 2011. This site, near McMurdo Station Antarctica, has been visited since the mid-1960s, but this mat was not observed until 2011. The finding of this site provides an unusual opportunity to study an Antarctic marine benthic habitat with active methane cycling and to examine the dynamics of recruitment and community succession of seep fauna including bacteria, archaea, protists and metazoans. This project will collect the necessary baseline data to facilitate further studies of Antarctic methane cycling. The concentration and source of methane will be determined at this site and at potentially analogous sites in McMurdo Sound. In addition to biogeochemical characterization of the sites, molecular analysis of the microbial community will quantify the time scales on which bacteria and archaea respond to methane input and provide information on rates of community development and succession in the Southern Ocean. Project activities will facilitate the training of at least one graduate student and results will be shared at both local and international levels. A female graduate student will be mentored as part of this project and data collected will form part of her dissertation. Lectures will be given in K-12 classrooms in Oregon to excite students about polar science. National and international audiences will be reached through blogs and presentations at a scientific conference. The PI\u0027s previous blogs have been used by K-12 classrooms as part of their lesson plans and followed in over 65 countries.\u003cbr/\u003e", "east": 166.666, "geometry": "POINT(166.666 -77.8)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Sea Floor; USAP-DC; Ross Sea; BACTERIA/ARCHAEA; NOT APPLICABLE", "locations": "Ross Sea; Sea Floor", "north": -77.8, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -77.8, "title": "EAGER: Elucidating the Antarctic Methane Cycle at the Cinder Cones Reducing Habitat.", "uid": "p0010030", "west": 166.666}, {"awards": "1056396 Morgan-Kiss, Rachael", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "datasets": [{"dataset_uid": "000241", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "url": "https://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Mon, 26 Feb 2018 00:00:00 GMT", "description": "This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Morgan-Kiss, Rachael", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -90.0, "title": "CAREER:Protist Nutritional Strategies in Permanently Stratified Antarctic Lakes", "uid": "p0000310", "west": -180.0}, {"awards": "1341362 Gast, Rebecca", "bounds_geometry": "POLYGON((-180 -65,-176 -65,-172 -65,-168 -65,-164 -65,-160 -65,-156 -65,-152 -65,-148 -65,-144 -65,-140 -65,-140 -66.5,-140 -68,-140 -69.5,-140 -71,-140 -72.5,-140 -74,-140 -75.5,-140 -77,-140 -78.5,-140 -80,-144 -80,-148 -80,-152 -80,-156 -80,-160 -80,-164 -80,-168 -80,-172 -80,-176 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78.5,160 -77,160 -75.5,160 -74,160 -72.5,160 -71,160 -69.5,160 -68,160 -66.5,160 -65,162 -65,164 -65,166 -65,168 -65,170 -65,172 -65,174 -65,176 -65,178 -65,-180 -65))", "dataset_titles": "Dinoflagellate sequende data", "datasets": [{"dataset_uid": "000240", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Dinoflagellate sequende data", "url": "http://www.ncbi.nlm.nih.gov/bioproject/428208"}], "date_created": "Mon, 12 Feb 2018 00:00:00 GMT", "description": "Kleptoplasty, the temporary acquisition and use of functional chloroplasts derived from algal prey, is viewed as an important model for the early evolution of the permanent, endosymbiotically-derived chloroplasts found in all permanently photosynthetic eukaryotes. This project will study the evolutionary history and expression of plastid-targeted genes in an abundant Antarctic dinoflagellate that steals chloroplasts from an ecologically important alga, the haptophyte Phaeocystis. Algae play an important role in the fixation and export of CO2 in the Southern Ocean, and this project will explore the genetic basis for the function of these chimeric cells with regard to their functional adaptation to extreme environments and will study the evolutionary history and expression of plastid-targeted genes in both the host and recipient. The project seeks to determine whether the kleptoplastidic dinoflagellate utilizes ancestral plastid proteins to regulate its stolen plastid, and how their transcription is related to environmental factors that are relevant to the Southern Ocean environment (temperature and light). To accomplish these goals, the project will utilize high throughput transcriptome analysis and RNA-sequencing experiments with the dinoflagellate and Phaeocystis. \u003cbr/\u003e\u003cbr/\u003eThis work will help biologists understand the environmental success of this alternative nutritional strategy, and to assess the potential impact of anthropogenic climate change on the organism. The project will also contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will support the mentoring of a graduate student and a postdoctoral fellow. The work is being accomplished as an international collaboration between US and Canadian scientists, and in addition to publishing results in peer-reviewed journals, the investigators will incorporate aspects of this work into public outreach activities. These include field data analysis opportunities for middle school students and science-based art projects with local schools and museums.", "east": -140.0, "geometry": "POINT(-170 -72.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gast, Rebecca", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -80.0, "title": "You are what you eat: The Role of Kleptoplasty in an Antarctic Dinoflagellate", "uid": "p0000302", "west": 160.0}, {"awards": "0944646 Bowser, Samuel", "bounds_geometry": "POLYGON((-160 -68,-159 -68,-158 -68,-157 -68,-156 -68,-155 -68,-154 -68,-153 -68,-152 -68,-151 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-151 -78,-152 -78,-153 -78,-154 -78,-155 -78,-156 -78,-157 -78,-158 -78,-159 -78,-160 -78,-160 -77,-160 -76,-160 -75,-160 -74,-160 -73,-160 -72,-160 -71,-160 -70,-160 -69,-160 -68))", "dataset_titles": "Evolution and Diversity of Antarctic Rhizarian Protists", "datasets": [{"dataset_uid": "600157", "doi": "10.15784/600157", "keywords": "Antarctica; Biota; Foraminifera; Oceans; Southern Ocean", "people": "Bowser, Samuel S.", "repository": "USAP-DC", "science_program": null, "title": "Evolution and Diversity of Antarctic Rhizarian Protists", "url": "https://www.usap-dc.org/view/dataset/600157"}], "date_created": "Wed, 23 Dec 2015 00:00:00 GMT", "description": "This research project will continue studies of a taxonomically definitive group of early evolving (single-chambered) Foraminifera at both multi-gene molecular and ultrastructural levels of analysis, in order to generate more robust and detailed phylogenies of these ecologically-important organisms. Studies will be extended to include members of the enigmatic genus Gromia, to better define their ecological significance and placement within the protistan supergroup Rhizara. Together, these structural and molecular data will be used to complete taxonomic descriptions of over 20 new rhizarian species. The research will develop rapid molecular screening methods for future ecological studies of rhizarian protists, and uncover the driving forces that led to their diversification. A range of educational activities will target local and national audiences, and include development of hands-on, standards-based, innovative science classroom activities. In addition, a short art/science documentary film depicting research on the biology and evolution of Antarctic rhizarian protists will form the basis of a workshop hosted by the Capital Region Center for Arts in Education.", "east": -150.0, "geometry": "POINT(-155 -73)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bowser, Samuel", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Evolution and Diversity of Antarctic Rhizarian Protists", "uid": "p0000413", "west": -160.0}, {"awards": "0838955 Gast, Rebecca", "bounds_geometry": "POLYGON((71.504166 -76.159164,71.5142214 -76.159164,71.5242768 -76.159164,71.5343322 -76.159164,71.5443876 -76.159164,71.554443 -76.159164,71.5644984 -76.159164,71.5745538 -76.159164,71.5846092 -76.159164,71.5946646 -76.159164,71.60472 -76.159164,71.60472 -76.2018032,71.60472 -76.2444424,71.60472 -76.2870816,71.60472 -76.3297208,71.60472 -76.37236,71.60472 -76.4149992,71.60472 -76.4576384,71.60472 -76.5002776,71.60472 -76.5429168,71.60472 -76.585556,71.5946646 -76.585556,71.5846092 -76.585556,71.5745538 -76.585556,71.5644984 -76.585556,71.554443 -76.585556,71.5443876 -76.585556,71.5343322 -76.585556,71.5242768 -76.585556,71.5142214 -76.585556,71.504166 -76.585556,71.504166 -76.5429168,71.504166 -76.5002776,71.504166 -76.4576384,71.504166 -76.4149992,71.504166 -76.37236,71.504166 -76.3297208,71.504166 -76.2870816,71.504166 -76.2444424,71.504166 -76.2018032,71.504166 -76.159164))", "dataset_titles": "Alternative Nutritional Strategies in Antarctic Protists", "datasets": [{"dataset_uid": "600103", "doi": "10.15784/600103", "keywords": "Biota; Microbiology; NBP0305; NBP0405; NBP0508; NBP1101; Oceans; Southern Ocean", "people": "Gast, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Alternative Nutritional Strategies in Antarctic Protists", "url": "https://www.usap-dc.org/view/dataset/600103"}], "date_created": "Wed, 30 Oct 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eMost organisms meet their carbon and energy needs using photosynthesis (phototrophy) or ingestion/assimilation of organic substances (heterotrophy). However, a nutritional strategy that combines phototrophy and heterotrophy - mixotrophy - is geographically and taxonomically widespread in aquatic systems. While the presence of mixotrophs in the Southern Ocean is known only recently, preliminary evidence indicates a significant role in Southern Ocean food webs. Recent work on Southern Ocean dinoflagellate, Kleptodinium, suggests that it sequesters functional chloroplasts of the bloom-forming haptophyte, Phaeocystis antarctica. This dinoflagellate is abundant in the Ross Sea, has been reported elsewhere in the Southern Ocean, and may have a circumpolar distribution. By combining nutritional modes. mixotrophy may offer competitive advantages over pure autotrophs and heterotrophs. \u003cbr/\u003e\u003cbr/\u003eThe goals of this project are to understand the importance of alternative nutritional strategies for Antarctic species that combine phototrophic and phagotrophic processes in the same organism. The research will combine field investigations of plankton and ice communities in the Southern Ocean with laboratory experiments on Kleptodinium and recently identified mixotrophs from our Antarctic culture collections. The research will address: 1) the relative contributions of phototrophy and phagotrophy in Antarctic mixotrophs; 2) the nature of the relationship between Kleptodinium and its kleptoplastids; 3) the distributions and abundances of mixotrophs and Kleptodinium in the Southern Ocean during austral spring/summer; and 4) the impacts of mixotrophs and Kleptodinium on prey populations, the factors influencing these behaviors and the physiological conditions of these groups in their natural environment. The project will contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will train graduate and undergraduate students at Temple University. Research findings and activities will be summarized for non-scientific audiences through the PIs\u0027 websites and through other public forums, and will involve middle school teachers via collaboration with COSEE-New England.", "east": 71.60472, "geometry": "POINT(71.554443 -76.37236)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.159164, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gast, Rebecca", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.585556, "title": "Collaborative Research: Alternative Nutritional Strategies in Antarctic Protists", "uid": "p0000490", "west": 71.504166}, {"awards": "9714299 Caron, David", "bounds_geometry": "POLYGON((-179.9984 -43.56676,-143.99865 -43.56676,-107.9989 -43.56676,-71.99915 -43.56676,-35.9994 -43.56676,0.000349999999997 -43.56676,36.0001 -43.56676,71.99985 -43.56676,107.9996 -43.56676,143.99935 -43.56676,179.9991 -43.56676,179.9991 -47.057693,179.9991 -50.548626,179.9991 -54.039559,179.9991 -57.530492,179.9991 -61.021425,179.9991 -64.512358,179.9991 -68.003291,179.9991 -71.494224,179.9991 -74.985157,179.9991 -78.47609,143.99935 -78.47609,107.9996 -78.47609,71.99985 -78.47609,36.0001 -78.47609,0.000349999999997 -78.47609,-35.9994 -78.47609,-71.99915 -78.47609,-107.9989 -78.47609,-143.99865 -78.47609,-179.9984 -78.47609,-179.9984 -74.985157,-179.9984 -71.494224,-179.9984 -68.003291,-179.9984 -64.512358,-179.9984 -61.021425,-179.9984 -57.530492,-179.9984 -54.039559,-179.9984 -50.548626,-179.9984 -47.057693,-179.9984 -43.56676))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002003", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9901"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "*** Caron 9714299 The analysis of microbial biodiversity of extreme environments is difficult because traditional methods for examining diversity are often ineffective for assessing species richness within these communities. Additional difficulties arise due to the difficulties of recreating and maintaining pertinent environmental features during sample collection and procession. This study focuses on the protistan assemblages (algae and protozoa) in the sea ice, sediment and ocean environments of the Ross Sea, Antarctica. The identification of protistan species in natural assemblages traditionally has entailed direct microscopical analyses as well as enrichment and culture techniques for assessing biodiversity. Determination of diversity for these assemblages in therefore susceptible to biases as a consequence of sampling, enrichment and culture, as well as selective losses due to sample preservation and concentration for microscopy. The goals of this project are: (1) to develop and apply molecular biological approaches to assess species diversity of small protists (algae and protozoa smaller than 100 micrometers) in ocean water, sea ice and sediment environments and (2) to obtain baseline physiological information on the growth rates, feeding rates and growth efficiencies of cultured protozoa under pertinent temperature regimes. Molecular biological studies will involve the use of PCR-based protocols to examine small subunit ribosomal RNA gene (srDNA) diversity. Approaches and techniques developed will be applicable to any other water body or sediment and would provide a means to examine the representativeness of protistan cultures in extant culture collections. ***", "east": 179.9991, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -43.56676, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Caron, David; Jeffries, Martin", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.47609, "title": "LEXEN: Protistan Biodiversity in Antarctic Marine Ecosystems: Molecular Biological and Traditional Approaches", "uid": "p0000625", "west": -179.9984}, {"awards": "0542111 Lonsdale, Darcy; 0542456 Caron, David", "bounds_geometry": "POLYGON((-179.9999 -43.5663,-143.99993 -43.5663,-107.99996 -43.5663,-71.99999 -43.5663,-36.00002 -43.5663,-0.000050000000016 -43.5663,35.99992 -43.5663,71.99989 -43.5663,107.99986 -43.5663,143.99983 -43.5663,179.9998 -43.5663,179.9998 -46.99537,179.9998 -50.42444,179.9998 -53.85351,179.9998 -57.28258,179.9998 -60.71165,179.9998 -64.14072,179.9998 -67.56979,179.9998 -70.99886,179.9998 -74.42793,179.9998 -77.857,143.99983 -77.857,107.99986 -77.857,71.99989 -77.857,35.99992 -77.857,-0.000049999999987 -77.857,-36.00002 -77.857,-71.99999 -77.857,-107.99996 -77.857,-143.99993 -77.857,-179.9999 -77.857,-179.9999 -74.42793,-179.9999 -70.99886,-179.9999 -67.56979,-179.9999 -64.14072,-179.9999 -60.71165,-179.9999 -57.28258,-179.9999 -53.85351,-179.9999 -50.42444,-179.9999 -46.99537,-179.9999 -43.5663))", "dataset_titles": "Do Crustacean Zooplankton Play a Pivotal Role in Structuring Heterotrophic Plankton Communities in the Ross Sea?; Expedition Data; NBP0802 data; Processed CurrentMeter Data from the Ross Sea near Antarctica acquired during the Nathaniel B. Palmer expedition NBP0801", "datasets": [{"dataset_uid": "000122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0802 data", "url": "https://www.rvdata.us/search/cruise/NBP0802"}, {"dataset_uid": "600059", "doi": "10.15784/600059", "keywords": "Antarctica; Biota; Crustacea; Oceans; Phytoplankton; Ross Sea; Southern Ocean", "people": "Lonsdale, Darcy", "repository": "USAP-DC", "science_program": null, "title": "Do Crustacean Zooplankton Play a Pivotal Role in Structuring Heterotrophic Plankton Communities in the Ross Sea?", "url": "https://www.usap-dc.org/view/dataset/600059"}, {"dataset_uid": "001517", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0801"}, {"dataset_uid": "601344", "doi": null, "keywords": "Antarctica; Cape Adare; Mooring; NBP0801; Physical Oceanography; Ross Sea; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed CurrentMeter Data from the Ross Sea near Antarctica acquired during the Nathaniel B. Palmer expedition NBP0801", "url": "https://www.usap-dc.org/view/dataset/601344"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Recent studies of marine ecosystems show conflicting evidence for trophic cascades, and in particular the relative strength of the crustacean zooplankton-phytoplankton link. The Ross Sea is a natural laboratory for investigating this apparent conflict. It is a site of seasonally high abundances of phytoplankton, characterized by regions of distinct phytoplankton taxa; the southcentral polynya is strongly dominated by the colony-forming prymnesiophyte Phaeocystis antarctica, while coastal regions of this sea are typically dominated by diatoms or flagellate species. Recent studies indicate that, while the south-central polynya exhibits a massive phytoplankton bloom, the poor food quality of P. antarctica for many crustacean zooplankton prevents direct utilization of much of this phytoplankton bloom. Rather, evidence suggests that indirect utilization of this production may be the primary mechanism by which carbon and energy become available to those higher trophic levels. Specifically, we hypothesize that nano and microzooplankton constitute an important food source for crustacean zooplankton (largely copepods and juvenile euphausiids) during the summer period in the Ross Sea where the phytoplankton assemblage is dominated by the prymnesiophyte. In turn, we also hypothesize that predation by copepods (and other Crustacea) controls and structures the species composition of these protistan assemblages. We will occupy stations in the south-central Ross Sea Polynya (RSP) and Terra Nova Bay (TNB) during austral summer to test these hypotheses. We hypothesize that the diatom species that dominate the phytoplankton assemblage in TNB constitute a direct source of nutrition to herbivorous/omnivorous zooplankton (relative to the situation in the south-central RSP). That is, the contribution of heterotrophic protists to crustacean diets will be reduced in TNB. Our research will address fundamental gaps in our knowledge of food web structure and trophic cascades, and provide better understanding of the flow of carbon and energy within the biological community of this perennially cold sea. The PIs will play active roles in public education (K-12) via curriculum development (on Antarctic biology) and teacher trainer activities in the Centers for Ocean Science Education Excellence (COSEE-West), an innovative, NSF-funded program centered at USC and UCLA.", "east": 179.9998, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP", "locations": null, "north": -43.5663, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Lonsdale, Darcy; Caron, Bruce", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -77.857, "title": "Collaborative Research: Do Crustacean Zooplankton Play a Pivotal Role in Structuring Heterotrophic Plankton Communities in the Ross Sea?", "uid": "p0000520", "west": -179.9999}]
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In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world's critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education & Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6.
Traditional models of oceanic food chains have consisted of photosynthetic algae (phytoplankton) being ingested by small animals (zooplankton), which were ingested by larger animals (fish). These traditional models changed as new methods allowed recognition of the importance of bacteria and other non-photosynthetic protozoa in more complex food webs. More recently, the wide-spread existence of mixotrophs (organisms that can both photosynthesize and ingest food particles) and their importance as microbial predators has been recognized in many oceanographic areas. In the Southern Ocean, the only two surveys of mixotrophs have suggested that there may be seasonal differences in their importance as predators. During the long polar night (winter), the ability of mixotrophs to ingest particulate food may aid in their survival thus ensuring a sufficient population in spring to support a phytoplankton bloom once photosynthesis rates can increase. Thus mixotrophs may provide a critical early food source upon which zooplankton and larger animals depend on for growth and reproduction. This project will advance understanding of mixotroph diversity and their ecological impact within the Southern Ocean microbial food web. Specifically, efforts will be focused on mixotrophy in the western Antarctica peninsula region during the austral spring and autumn when there are likely to be changes in the relative importance of photosynthesis and ingestion to mixotrophs. The project will provide research opportunities for undergraduate and graduate students and a post-doctoral researcher. There will be real-time outreach from the Southern Ocean to the public via blogs and interviews, and to high school art students through an established program that blends science and art education. Despite traditional views of protists as either "phototrophic" or "heterotrophic," there are many photosynthetic protists that consume prey (mixotrophy). Mixotrophy is a widespread phenomenon in aquatic systems and phytoplankton groups with known mixotrophic species, notably chrysophytes, cryptophytes, prymnesiophytes, prasinophytes and dinoflagellates, are present and often abundant in Antarctic waters. However, in the Southern Ocean, the presence of mixotrophic phytoflagellates has been surveyed only twice prior to this project: in the Ross Sea during Austral spring 2008 and summer 2011. The primary goals of the project are to gain better understanding of mixotroph diversity and their ecological impact with respect to the Southern Ocean microbial food web. The contribution of mixotrophs to primary production and bacterial consumption is likely linked to the taxonomic composition of the community and the abundance of particular species. Abundances of novel mixotrophic species will be evaluated via qPCR, which will be coupled with assessments of rates of feeding and photosynthesis with the goal of describing how active mixotrophs direct the movement of carbon through food webs. These experiments will help the determination of how viable and widespread mixotrophy is as a nutritional strategy in polar waters and give direct information on the currently unknown diversity of mixotrophic taxa under different environmental conditions occurring in austral spring and autumn. Furthermore, the methods will simultaneously yield information on the whole communities of protists - mixotrophic, phototrophic and heterotrophic. In addition, a method to examine aspects of the taxonomic and functional diversities of the bacterivorous/mixotrophic community will be employed. A thymidine analog (BrdU) will be used to label DNA of eukaryotes feeding on bacteria. The BrdU-labeled eukaryotic DNA will be isolated using immunoprecipitation. High-throughput sequencing of the labeled DNA (bacterivores) versus unlabeled community DNA will determine the diversity of bacterivorous mixotrophs relative to other microeukaryotes. Flow cytometric sorting based on chlorophyll to focus on mixotrophic species. These approaches will elucidate a gap in current knowledge of the influence of microbial interactions in the Southern Ocean under different conditions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Overview:
Antarctic biota face increasing stressors from warming oceans. A key question is: What will be the effect of warming waters on Antarctic biota? A gap in our knowledge is the identify of early harbingers of new stressors. In our recent field season, we unexpectedly discovered pink, wart-like neoplasms in Antarctic notothenioid fish, including Trematomus scotti (crowned notothen) and Nototheniops larseni (painted notothen). Neoplasms affected about 30% of T. scotti collected in Andvord Bay on the West Antarctic Peninsula and covered 10 to 30% of the bodies of affected individuals, usually in one contiguous patch. We collected samples from affected and apparently unaffected controls. We could not find evidence of any similar outbreak. Our overall goal is to learn the biological origins of this neoplasm and how it affects cellular function and organismal physiology.
Intellectual Merit:
Aim 1: Pathogenic agents. Aim 1a: To test the hypothesis that a virus causes the neoplasm. Methods involve isolating and sequencing viral nucleic acids from neoplasms and from unaffected skin and comparing sequences to known viruses. Aim 1b: To test the hypothesis that neoplasms are hosts to parasites not present in healthy skin. Methods include tissue sections and DNA sequencing to find evidence of parasitic organisms. Significance: achieving Aim 1 will narrow down possible etiological agents. An untested possibility is that environmental contaminants cause the condition; exploring that hypothesis would require further sampling outside the limits of an EAGER proposal.
Aim 2: Cell-level pathology. Aim 2a: To test the hypothesis that the histopathology of the neoplasms is similar to other known skin neoplasias; alternatively, it might be a previously unknown type of neoplasia. Methods involve the examination of histological sections to identify pathology-specific characters. Aim 2b: To find effects of neoplasms on cell function. Methods involve performing whole-genome transcriptomics of affected and normal skin by RNA-seq and aligning reads to a T. scotti reference genome. Significance: achieving Aim 2 will define the cell biology and gene-expression phenotypes of the neoplasia, thus suggesting mechanisms that cause it.
[Note: NSF deleted funds specifically to achieve the Aim 3, which nevertheless appears here to represent the original proposal.] Aim 3: Organismal pathology. Aim 3a: To test the hypothesis that the neoplasm has adverse effects on growth and physiology. Methods are to perform morphometrics in fish with neoplasms compared to age-matched controls from otolith studies. Aim 3b: To test the hypothesis that the neoplasia affects reproductive traits. Methods compare reproductive effort in affected and unaffected individuals. Significance: if the neoplasia has little consequences on growth and reproduction, our worry about its spread will be lessened, but if it is harmful, then Antarctic ecology, which largely depends on notothenioid fish, might be in danger.
Achieving Aims 1-3 will advance knowledge by identifying the causes of a neoplasia outbreak in Antarctic fish. Work is potentially transformative because it might represent an early sign of Antarctic fish responses to the stress of global climate change. Proposed work would be the first to investigate a neoplasia outbreak in Antarctic fish. We will assess the project’s success by whether we identify a causative agent and its effects on physiology.
Broader Impacts:
Aim 4: Publicizing the neoplasia. We aim to raise awareness of the outbreak and publicize its distinct diagnostic features, including assays to detect it, by contributing to groups that track Antarctic ecosystems.
Aim 5: Inclusion. We will involve underrepresented groups in scientific research with authentic research experiences.
Achieving Aims 4 and 5 will benefit society because they will disseminate to scientific and lay communities a potential early-warning system for the effects of an apparently new neoplasia affecting, at least locally, a large proportion of a fish population. Dissemination will stir research to determine whether this neoplasia outbreak is an isolated event or is becoming a general phenomenon, and thus a concern for Antarctic ecosystems. Proposed research will enhance research infrastructure by providing tools to identify the neoplasia. Finally, the project will broaden access to research careers by exposing underserved high school students and undergraduates to an exciting live research project.
The coastal Antarctic is undergoing great environmental change. Physical changes in the environment, such as altered sea ice duration and extent, have a direct impact on the phytoplankton and bacteria species which form the base of the marine foodweb. Photosynthetic phytoplankton are the ocean's primary producers, transforming (fixing) CO2 into organic carbon molecules and providing a source of food for zooplankton and larger predators. When phytoplankton are consumed by zooplankton, or killed by viral attack, they release large amounts of organic carbon and nutrients into the environment. Heterotrophic bacteria must eat other things, and function as "master recyclers", consuming these materials and converting them to bacterial biomass which can feed larger organisms such as protists. Some protists are heterotrophs, but others are mixotrophs, able to grow by photosynthesis or heterotrophy. Previous work suggests that by killing and eating bacteria, protists and viruses may regulate bacterial populations, but how these processes are regulated in Antarctic waters is poorly understood. This project will use experiments to determine the rate at which Antarctic protists consume bacteria, and field studies to identify the major bacterial taxa involved in carbon uptake and recycling. In addition, this project will use new sequencing technology to obtain completed genomes for many Antarctic marine bacteria. To place this work in an ecosystem context this project will use microbial diversity data to inform rates associated with key microbial processes within the PALMER ecosystem model.
This project addresses critical unknowns regarding the ecological role of heterotrophic marine bacteria in the coastal Antarctic and the top-down controls on bacterial populations. Previous work suggests that at certain times of the year grazing by heterotrophic and mixotrophic protists may meet or exceed bacterial production rates. Similarly, in more temperate waters bacteriophages (viruses) are thought to contribute significantly to bacterial mortality during the spring and summer. These different top-down controls have implications for carbon flow through the marine foodweb, because protists are grazed more efficiently by higher trophic levels than are bacteria. This project uses a combination of grazing experiments and field observations to assess the temporal dynamics of mortality due to temperate bacteriophage and protists. Although many heterotrophic bacterial strains observed in the coastal Antarctic are taxonomically similar to strains from other regions, recent work suggest that they are phylogenetically and genetically distinct. To better understand the ecological function and evolutionary trajectories of key Antarctic marine bacteria, their genomes will be isolated and sequenced. Then, these genomes will be used to improve the predictions of the paprica metabolic inference pipeline, and our understanding of the relationship between heterotrophic bacteria and their major predators in the Antarctic marine environment. Finally, the research team will modify the Regional Test-Bed Model model to enable microbial diversity data to be used to optimize the starting conditions of key parameters, and to constrain the model's data assimilation methods.
Methane is a potent greenhouse gas that is naturally emitted into the oceans by geologic seeps and microbial production. Based on studies of persistent deep-sea seeps at mid- and northern latitudes, researchers have learned that bacteria and archaea can create a "sediment filter" that oxidizes methane prior to its release. Antarctica is thought to contain large reservoirs of organic carbon buried beneath its ice which could a quantity of methane equivalent to all of the permafrost in the Arctic and yet we know almost nothing about the methane oxidizing microbes in this region. How these microbial communities develop and potentially respond to fluctuations in methane levels is an under-explored avenue of research. A bacterial mat was recently discovered at 78 degrees south, suggesting the possible presence of a methane seep, and associated microbial communities. This project will explore this environment in detail to assess the levels and origin of methane, and the nature of the microbial ecosystem present. <br/> <br/>An expansive bacterial mat appeared and/or was discovered at 78 degrees south in 2011. This site, near McMurdo Station Antarctica, has been visited since the mid-1960s, but this mat was not observed until 2011. The finding of this site provides an unusual opportunity to study an Antarctic marine benthic habitat with active methane cycling and to examine the dynamics of recruitment and community succession of seep fauna including bacteria, archaea, protists and metazoans. This project will collect the necessary baseline data to facilitate further studies of Antarctic methane cycling. The concentration and source of methane will be determined at this site and at potentially analogous sites in McMurdo Sound. In addition to biogeochemical characterization of the sites, molecular analysis of the microbial community will quantify the time scales on which bacteria and archaea respond to methane input and provide information on rates of community development and succession in the Southern Ocean. Project activities will facilitate the training of at least one graduate student and results will be shared at both local and international levels. A female graduate student will be mentored as part of this project and data collected will form part of her dissertation. Lectures will be given in K-12 classrooms in Oregon to excite students about polar science. National and international audiences will be reached through blogs and presentations at a scientific conference. The PI's previous blogs have been used by K-12 classrooms as part of their lesson plans and followed in over 65 countries.<br/>
This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.
Kleptoplasty, the temporary acquisition and use of functional chloroplasts derived from algal prey, is viewed as an important model for the early evolution of the permanent, endosymbiotically-derived chloroplasts found in all permanently photosynthetic eukaryotes. This project will study the evolutionary history and expression of plastid-targeted genes in an abundant Antarctic dinoflagellate that steals chloroplasts from an ecologically important alga, the haptophyte Phaeocystis. Algae play an important role in the fixation and export of CO2 in the Southern Ocean, and this project will explore the genetic basis for the function of these chimeric cells with regard to their functional adaptation to extreme environments and will study the evolutionary history and expression of plastid-targeted genes in both the host and recipient. The project seeks to determine whether the kleptoplastidic dinoflagellate utilizes ancestral plastid proteins to regulate its stolen plastid, and how their transcription is related to environmental factors that are relevant to the Southern Ocean environment (temperature and light). To accomplish these goals, the project will utilize high throughput transcriptome analysis and RNA-sequencing experiments with the dinoflagellate and Phaeocystis. <br/><br/>This work will help biologists understand the environmental success of this alternative nutritional strategy, and to assess the potential impact of anthropogenic climate change on the organism. The project will also contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will support the mentoring of a graduate student and a postdoctoral fellow. The work is being accomplished as an international collaboration between US and Canadian scientists, and in addition to publishing results in peer-reviewed journals, the investigators will incorporate aspects of this work into public outreach activities. These include field data analysis opportunities for middle school students and science-based art projects with local schools and museums.
This research project will continue studies of a taxonomically definitive group of early evolving (single-chambered) Foraminifera at both multi-gene molecular and ultrastructural levels of analysis, in order to generate more robust and detailed phylogenies of these ecologically-important organisms. Studies will be extended to include members of the enigmatic genus Gromia, to better define their ecological significance and placement within the protistan supergroup Rhizara. Together, these structural and molecular data will be used to complete taxonomic descriptions of over 20 new rhizarian species. The research will develop rapid molecular screening methods for future ecological studies of rhizarian protists, and uncover the driving forces that led to their diversification. A range of educational activities will target local and national audiences, and include development of hands-on, standards-based, innovative science classroom activities. In addition, a short art/science documentary film depicting research on the biology and evolution of Antarctic rhizarian protists will form the basis of a workshop hosted by the Capital Region Center for Arts in Education.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). <br/><br/>Most organisms meet their carbon and energy needs using photosynthesis (phototrophy) or ingestion/assimilation of organic substances (heterotrophy). However, a nutritional strategy that combines phototrophy and heterotrophy - mixotrophy - is geographically and taxonomically widespread in aquatic systems. While the presence of mixotrophs in the Southern Ocean is known only recently, preliminary evidence indicates a significant role in Southern Ocean food webs. Recent work on Southern Ocean dinoflagellate, Kleptodinium, suggests that it sequesters functional chloroplasts of the bloom-forming haptophyte, Phaeocystis antarctica. This dinoflagellate is abundant in the Ross Sea, has been reported elsewhere in the Southern Ocean, and may have a circumpolar distribution. By combining nutritional modes. mixotrophy may offer competitive advantages over pure autotrophs and heterotrophs. <br/><br/>The goals of this project are to understand the importance of alternative nutritional strategies for Antarctic species that combine phototrophic and phagotrophic processes in the same organism. The research will combine field investigations of plankton and ice communities in the Southern Ocean with laboratory experiments on Kleptodinium and recently identified mixotrophs from our Antarctic culture collections. The research will address: 1) the relative contributions of phototrophy and phagotrophy in Antarctic mixotrophs; 2) the nature of the relationship between Kleptodinium and its kleptoplastids; 3) the distributions and abundances of mixotrophs and Kleptodinium in the Southern Ocean during austral spring/summer; and 4) the impacts of mixotrophs and Kleptodinium on prey populations, the factors influencing these behaviors and the physiological conditions of these groups in their natural environment. The project will contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will train graduate and undergraduate students at Temple University. Research findings and activities will be summarized for non-scientific audiences through the PIs' websites and through other public forums, and will involve middle school teachers via collaboration with COSEE-New England.
*** Caron 9714299 The analysis of microbial biodiversity of extreme environments is difficult because traditional methods for examining diversity are often ineffective for assessing species richness within these communities. Additional difficulties arise due to the difficulties of recreating and maintaining pertinent environmental features during sample collection and procession. This study focuses on the protistan assemblages (algae and protozoa) in the sea ice, sediment and ocean environments of the Ross Sea, Antarctica. The identification of protistan species in natural assemblages traditionally has entailed direct microscopical analyses as well as enrichment and culture techniques for assessing biodiversity. Determination of diversity for these assemblages in therefore susceptible to biases as a consequence of sampling, enrichment and culture, as well as selective losses due to sample preservation and concentration for microscopy. The goals of this project are: (1) to develop and apply molecular biological approaches to assess species diversity of small protists (algae and protozoa smaller than 100 micrometers) in ocean water, sea ice and sediment environments and (2) to obtain baseline physiological information on the growth rates, feeding rates and growth efficiencies of cultured protozoa under pertinent temperature regimes. Molecular biological studies will involve the use of PCR-based protocols to examine small subunit ribosomal RNA gene (srDNA) diversity. Approaches and techniques developed will be applicable to any other water body or sediment and would provide a means to examine the representativeness of protistan cultures in extant culture collections. ***
Recent studies of marine ecosystems show conflicting evidence for trophic cascades, and in particular the relative strength of the crustacean zooplankton-phytoplankton link. The Ross Sea is a natural laboratory for investigating this apparent conflict. It is a site of seasonally high abundances of phytoplankton, characterized by regions of distinct phytoplankton taxa; the southcentral polynya is strongly dominated by the colony-forming prymnesiophyte Phaeocystis antarctica, while coastal regions of this sea are typically dominated by diatoms or flagellate species. Recent studies indicate that, while the south-central polynya exhibits a massive phytoplankton bloom, the poor food quality of P. antarctica for many crustacean zooplankton prevents direct utilization of much of this phytoplankton bloom. Rather, evidence suggests that indirect utilization of this production may be the primary mechanism by which carbon and energy become available to those higher trophic levels. Specifically, we hypothesize that nano and microzooplankton constitute an important food source for crustacean zooplankton (largely copepods and juvenile euphausiids) during the summer period in the Ross Sea where the phytoplankton assemblage is dominated by the prymnesiophyte. In turn, we also hypothesize that predation by copepods (and other Crustacea) controls and structures the species composition of these protistan assemblages. We will occupy stations in the south-central Ross Sea Polynya (RSP) and Terra Nova Bay (TNB) during austral summer to test these hypotheses. We hypothesize that the diatom species that dominate the phytoplankton assemblage in TNB constitute a direct source of nutrition to herbivorous/omnivorous zooplankton (relative to the situation in the south-central RSP). That is, the contribution of heterotrophic protists to crustacean diets will be reduced in TNB. Our research will address fundamental gaps in our knowledge of food web structure and trophic cascades, and provide better understanding of the flow of carbon and energy within the biological community of this perennially cold sea. The PIs will play active roles in public education (K-12) via curriculum development (on Antarctic biology) and teacher trainer activities in the Centers for Ocean Science Education Excellence (COSEE-West), an innovative, NSF-funded program centered at USC and UCLA.