Environmental Research
Oral Presentations
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Organizing the 'World of Water': Historical perspectives and future directions.
Matthew Iles Shih, Robert Varady, PhDKeywords: Natural Resource Management, International Hydrological Programme, History, Global Water Initiatives Abstract:Amidst rapidly growing concern over the emerging "global water crisis," a wide array of scholars, citizen groups and public officials are struggling to envision new policy frameworks and institutional arrangements capable of promoting human health and wellbeing through the rational and equitable management of the world’s increasingly strained freshwater resources. Doing so, however, will require the active participation of a diverse and numerous population of "Global Water Initiatives" (GWIs)—a dynamic collection of professional societies, organized events, designated periods, and independent multilateral initiatives that has coalesced around the problem of freshwater research and management over course of the past century. Unfortunately, as a dynamic collectivity these initiatives are little understood. Combining historical analysis and recent survey data, we seek to help fill this void by (1) characterizing the historical development of GWIs as an institutional field; (2) identifying current challenges to and opportunities for reform; (3) elucidating strategies for rendering the field more effective; and (4) locating the most appropriate position within the field from which to promote these strategies. Our research distinguishes several salient historical trends—including proliferation, diversification, and overlap—and shows how they have produced the rather complicated institutional topography that contemporary sector-wide reformers must navigate. We conclude by outlining several strategies for transforming this landscape and suggest reasons why one organization in particular, the International Hydrological Programme, may be best positioned to facilitate this process.
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IL-1 mediates persistent but not acute ozone-induced airway hyperreactivity
Kirsten Blensly, David B Jacoby, Allison D FryerKeywords: Lungs, Parasympathetic Nerves, Cytokines, Eosinophils, Asthma Abstract:Ozone (O3) exposure causes airway hyperreactivity, lasting at least 3 days, and increases interleukin-1 (IL-1) in human and animal lungs. Eosinophil depletion prevents O3 induced airway hyperreactivity 1 day post O3 but worsens airway hyperreactivity 3 days post O3. Thus, the mechanism of hyperreactivity changes between 1 and 3 days following O3 exposure in guinea pigs. O3 increases IL-1β in bone marrow. To test whether IL-1β mediates airway hyperreactivity 1 and 3 days post O3 guinea pigs were treated with an IL-1 receptor antagonist (Kineret, 30mg/kg ip) 30 minutes before exposure to filtered air or O3 (2ppm, 4 hours). One or 3 days later electrical stimulation of both vagus nerves, in anesthetized animals, caused bronchoconstriction that was significantly potentiated in O3 exposed animals compared to air exposed controls. The IL-1 antagonist prevented airway hyperreactivity 3 days but not 1 day post O3. Acetylcholine (1-10ug/kg, iv) induced bronchoconstriction was not changed 1 or 3 days post O3 but was increased in O3 exposed animals treated with the IL-1 antagonist. In bronchoalveolar lavage the IL-1 antagonist did not change inflammatory cell numbers in either O3 or air exposed animals at either time point. These data confirm the mechanism of airway hyperreactivity changes over three days following ozone to become IL-1 dependent.
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A COMPUTATIONAL MODEL FOR STEROID HORMONE AND VITELLOGENIN PROFILES IN UNEXPOSED AND EE2-EXPOSED MALE FHMs
Zhenhong Li, Kroll KJ, Reyero NG, Szabo NJ, Ekman DR, Collette TW, Denslow ND, Ankley GT, Watanabe KHKeywords: Computational Model, Male Fathead Minnow, Steroid Hormones, Vitellogenin, 17alpha-Ethinylestradiol Abstract:Endocrine disrupting chemicals (e.g., estrogens) discharged into the aquatic environment are known to affect reproductive endpoints in fish. 17 alpha ethynylestradiol (EE2), a synthetic estrogen used in birth control pills, is discharged from sewage treatment plants into water bodies throughout the United States. A goal of our research is to understand how exposure to EE2 affects reproductive endpoints such as concentrations of steroid hormones (i.e., 17 beta estradiol (E2), testosterone (T), and 11-ketotestosterone (KT)) and vitellogenin (Vtg, a precursor to an egg yolk protein) in male fathead minnows (FHM, Pimephales promelas). In this study, we developed a physiologically based computational model comprising six tissue compartments. Mass balances were used to formulate a set of differential equations describing E2, T, KT, EE2 , and Vtg kinetics. The model was calibrated with data from 75 unexposed control FHMs and 9 FHMs exposed to 10 ng/L and 50 ng/L EE2 for 48 hours. The model successfully predicted the medians and variances of EE2 and Vtg concentrations in both unexposed and EE2 -exposed FHMs; and successfully predicted the medians of E2, T and KT in both unexposed and EE2 -exposed FHMs, but underestimated the variances of E2, T and KT. Our model only simulated one major pathway of E2, T and KT metabolism, which might lead to the underestimated variances. The model may be used to estimate the effects of EE2 exposure in male FHMs, and may also be used to study the biochemical processes related to steroidgenesis.
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Coastal Upwelling and the Columbia River Plume
Charles Seaton, Charles Seaton, Antonio BaptistaKeywords: Indicators, Ecology, Plume, Estuary Abstract:The Columbia River estuary generates a large plume. The characteristics of the Columbia River plume are determined in part by the ocean end member for the Columbia River estuary. Using 11 years of temperature data and 5 years of salinity data from the CORIE observation network in the Columbia River estuary, we developed an upwelling classifier that categorizes the ocean end member of the estuary as freshly upwelled water or downwelled older surface water for each tidal day. We compared the results of the upwelling classifier and the along shore wind stress, and found that the range of values of integrated wind stress were distinct (3% overlap) for the upwelled and downwelled categories of the classifier. The time scale of the response of the estuary to the along shore wind stress was almost exactly the same as that of the coastal ocean. We conclude that coastal upwelling conditions are directly reflected in the ocean end member of the Columbia River estuary. Comparisons of the results of the classifier to nitrate-temperature-salinity data from RISE and CMOP cruises shows that there is a reasonable but imperfect agreement between classification of the estuarine ocean end member as upwelled and matching temperatures between the ocean end member and high nitrate coastal water.
Poster Presentations
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Microbial Diversity in a Ultra-Thick Mn-Fe Oxide Encrusted Microbial Mat From the 5000 Meter-Deep Off-Axis Hydrothermal Vent 'Ula Nui, Hawaii
Richard Davis, Craig L. Moyer, Andrea C. Curtis, Andrew W. Han, Hubert Staudigel, and Bradley M. TeboKeywords: Biofilm, Microbiology, Manganese, Iron, Hydrothemral Abstract:The ‘Ula Nui Vent Field is located at 5000 m depth on the southern flank of Loihi Seamount. The vent field exhibited abundant low temperature (≈0.2 °C above ambient) ultra-diffuse seeps which were covered with extensive microbial mat material. The microbial mats consisted of a 0.5-3 cm thick upper mat comprised of laminated layers of manganese oxides and iron oxides which overlayed a flocculent iron oxide mat that could attain depths of over 1 m. These mats covered a minimum lateral area of 4000 square meters on the seafloor.
Bacterial communities from the top and bottom mats were analyzed using T-RFLP community fingerprinting coupled with clone library analysis which allowed targeted fluorescent in situ hybridization (FISH) and batch enrichments of the microbial communities. T-RFLP electropherograms indicate dominance of zeta-Proteobacteria in both the top and lower mat. Cluster analysis of T-RFLP fingerprints show strong correlation between the bottom mat and microbial mats found in the hydrothermally active Pele’s Pit at Loihi Seamount. The top mat clusters with iron and manganese oxide encrusted microbial mats found at seeps on Loihi Seamount. Clone library analysis show the presence of zeta-Proteobacteria and Planctomycete anammox phylotypes implying neutrophilic iron oxidation and anaerobic ammonia oxidation were active metabolisms in the community. Microscopic analysis showed biogenic iron oxide structures with attached bacterial cells. Enrichment cultures of anaerobic iron/manganese oxidation coupled with nitrate reduction suggest that these metabolisms may also be important in ‘Ula Nui microbial mats.
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Biogeography of the Dominant Bacterial Taxa Across a Salinity Gradient In the Columbia River Estuary
Daniel Murphy, L. Herfort, M. Selby, P. Zuber and H. M. SimonKeywords: Abstract:The National Science Foundation Center for Coastal Margin Observation and Prediction (CMOP) is a river to ocean observatory being developed to gather long-term physical, chemical and biological information. A primary goal of CMOP is to achieve transformative understanding of the composition and activities of microbial assemblages by relating microbial productivity to regional productivity and biogeochemical cycles in the Pacific Northwest coastal margins. The microbiology component of CMOP has undertaken a study to understand the ecology of microorganisms within the Columbia River estuary. The Columbia River estuary is a dynamic environment where the mixing of freshwater and seawater as well as the deposition and resuspension of particles originating from many sources generates a high gradient region. In this region, chemical and physical variability almost certainly impact the composition and activities of microbial assemblages. Microbial diversity within the estuary is expected to be high due to the dynamic nature of the estuarine environment. Analysis of small subunit (SSU) ribosomal RNA (rRNA) genes was conducted across a salinity gradient within the estuary. Construction and analysis of clone libraries, together with PCR - Single Strand Conformation Polymorphism (SSCP) fingerprinting analysis resulted in identification of the dominant microbial taxa and their relative population sizes. Analyses of samples collected at several locations along the estuarine salinity gradient indicated a river to ocean variability with respect to bacterial community composition. Across the gradient, microbial assemblages were dominated by a few bacterial phyla with a moderate degree of diversity at the species level.
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Vertical transmission of ammonia-oxidizing archaea in the tropical sponge Corticium sp.
Andrew Han, Ann-Chee Cheng, Margo HaygoodKeywords: Symbiosis, Marine Sponge, Archaea Abstract:Marine sponges (phylum Porifera) are sessile, filter-feeding organisms and are among the most ancient animal phyla. Sponges harbor diverse microbial communities that have a variety of functions within the host. Studies of bacterial communities have dominated sponge-microbe research due to their potential for production of bioactive secondary metabolites. However, studies focusing on archaeal communities are rapidly becoming more prevalent and are helping to close gaps in our knowledge of sponge-microbe interactions. Here we report the presence of putative ammonia-oxidizing archaea (AOA) in the tropical sponge Corticium sp. Phylogenetic analysis of archaeal 16S rRNA gene sequences amplified from Corticium sp. samples revealed the Corticium-associated archaea are part of the marine group I Crenarchaeota. Specific probes were designed to localize Corticium-associated archaea within the host tissue using fluorescent in situ hybridization (FISH). FISH analysis revealed the clustering of Corticium-associated archaea in sponge embryos, which are brooded within the adult tissue. This evidence for vertical transmission of archaea in Corticium suggests a specialized relationship between the archaea and their sponge host. Recent studies have suggested widespread ability of marine crenarchaeotes for ammonia oxidation. Archaea-specific ammonia monooxygenase subunit A genes, a functional biomarker for ammonia-oxidation, were recovered from Corticium sp. samples by PCR amplification. The presence of AOA in marine sponges might suggest the dependence of sponges on archaea for ammonia detoxification.
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Characterization of microbial assemblages involved in biogeochemical cycling of nitrogen in the northeast Pacific hypoxic zone.
Suzanne De Lorenzo, Brad Tebo, Peter Zuber, Joe Needoba, Holly Simon, Lydie Herfort, Suzanna BrauerKeywords: Oxygen Minimum Zone, Hypoxia, Anammox Abstract:Recent studies (Kuypers et al 2005; Hamersley et al 2007) have shown that the anaerobic oxidation of ammonium by anammox bacteria rather than denitrification is the primary pathway catalyzing the loss of nitrogen from marine oxygen minimum zones (OMZ), particularly in highly productive eastern boundary upwelling systems such as the Humboldt and Benguela Currents. These are some of the most productive ecosystems in the world, often characterized by high primary productivity resulting in mid-column hypoxia or anoxia. More than 30% of total global nitrogen loss occurs in OMZs suggesting a dramatic role in global biochemical cycling. To date, no research regarding nitrogen cycling has been conducted in the OMZ in the California Current, a similar system in the Northeast Pacific. Here we plan to combine molecular and biogeochemical techniques to compare active bacterial assemblages, including anammox bacteria, in and out of the hypoxic zone off the coast of central Oregon. Results from this study will further our understanding of the importance of microbial assemblages in the nitrogen cycle of the California Current OMZ .
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Efficacy of Cryogenic Subsurface Core Sampling for Molecular Biological Tools
Christina Brow, Rick Johnson, Holly SimonKeywords: Real-Time Qpcr, Bioremediation Abstract:Ideally, subsurface remediation strategies should be designed based on knowledge of indigenous microorganisms, their metabolic capabilities, and how they respond to changing environmental conditions. Molecular biological tools ( MBTs) such as real-time qPCR, have tremendous potential to improve the design, field performance, and monitoring of subsurface remediation. However, application of MBTs to subsurface remediation presents many challenges. With respect to environmental sample collection, traditional coring results in redistribution of pore fluids during sample removal from the subsurface . This could likely obscure biogeochemical interfaces important for understanding the remediation process. Additionally, application of MBTs to ongoing remediation activities would necessitate the timely processing of large numbers of samples in a manner that would be the least cost-prohibitive.
Pore water redistribution and subsequent sample contamination can be eliminated by freezing the core sample in-situ prior to extraction. We are developing an integrated approach to demonstrate the efficacy of cryogenic subsurface core sampling for a suite of MBTs. Laboratory experiments demonstrate no difference in our ability to amplify DNA with real-time qPCR between frozen and unfrozen cores.
Furthermore, comparable results are obtained when analyzing the real-time qPCR data using the traditional standard curve approach, and a standard curve-independent method, DART -PCR, that determines PCR amplification efficiency from the kinetics of the fluorescence curve. The use of this analysis approach could greatly reduce overall processing costs by eliminating the need to run standard curves with each reaction.