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Ecological Exposure Research Division Publications: 2007
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This page lists publication titles, citations and abstracts produced by NERL's Ecological Exposure Research Division for the year 2007, organized by Publication Type. Your search has returned
56 Matching Entries.
See also Ecological Exposure Research Division citations with abstracts:
1999,
2000,
2001,
2002,
2003,
2004,
2005,
2006,
2007,
2008
Technical Information Manager: Linda Ransick - (513) 569-7395 or ransick.linda@epa.gov
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Presented/Published |
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Diatoms as Indicators of Isolated Herbaceous Wetland Condition in Florida, USA |
03/01/2007
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Lane, C. R. AND M. T. BROWN. Diatoms as Indicators of Isolated Herbaceous Wetland Condition in Florida, USA. ECOLOGICAL INDICATORS. Elsevier Science Ltd, New York, NY, 7(3):521-540, (2007).
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Benthic, epiphytic, and phytoplanktonic diatoms, as well as soil and water physical-chemical parameters, were sampled from 70 small (~1 ha) isolated depressional herbaceous wetlands located along a gradient of human disturbance in peninsular Florida to: 1) compare assemblage structure between types; 2) analyze the effects of ecoregion on diatom distribution; 3) develop biological indicators of wetland condition and ultimately an index of biological integrity using a single assemblage; and 4) examine autecological relationships between diatom structure and environmental variables. Collected diatom samples were enumerated to 250 valves and identified to species or subspecies. An on-site assessment of wetland condition was made using the Wetland Rapid Assessment Procedure (WRAP), and a landscape-scale human disturbance score (Landscape Development Intensity index, LDI) was calculated for each site using aerial photos and GIS. Compositional differences were found between samples from the same site, but no significant differences were found when comparing composition across sites. Results equivocated on differences in regional composition among types, suggesting possible dissimilarities between diatom flora of southern and northern Florida, driven by diversity within reference conditions. Impaired sites tended towards homogenization with increased disturbance. Metrics were developed using the full peninsular dataset. Mantel's test and non-metric multidimensional scaling (NMDS) identified epiphytic diatoms as the most responsive to human disturbance. Strong correlations were found between epiphytic NMDS scores and soil pH, specific conductivity, water total phosphorous, and LDI. Metrics to assess wetland condition were developed using epiphytic abundance data. Epiphytic taxa sensitive or tolerant to human landscape modification were identified using Indicator Species Analysis, and autecological indices relating diatom sensitivity to nutrients, pH, dissolved oxygen levels, saprobity, salinity, and trophic status were calculated. Fourteen final metrics were identified, scored on an ordinal scale, and combined into the Diatom Index of Wetland Condition (DIWC). The DIWC was highly correlated with both the WRAP and LDI scores (Spearman's rs = -0.68, p < 0.001 and rs = -0.71, p < 0.001, respectively), indicating the utility of epiphytic diatom taxa to assess isolated wetland condition in Florida.
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Assessment of Isolated Wetland Condition in Florida Using Epiphytic Diatoms at Genus, Species, and Subspecies Taxonomic Resolution |
06/01/2007
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LANE, C. R. Assessment of Isolated Wetland Condition in Florida Using Epiphytic Diatoms at Genus, Species, and Subspecies Taxonomic Resolution. ECOSYSTEM HEALTH 4:219-230, (2007).
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Diatoms are useful indicators of aquatic conditions, and metrics based on published autecological indicator values have been developed utilizing their sensitivities to various ambient physical and chemical conditions. The autecological values often differ within genera, and indeed within species taxonomic levels, requiring identification to subspecies taxonomic level for accurate application. This study was conducted to determine if autecological metrics, and ultimately indices of biotic integrity, could be developed using mean autecological values at the genus, species, and subspecies taxonomic levels, and to investigate the potential benefits of increased taxonomic resolution. Sixty-nine isolated herbaceous wetlands in various land use modalities in peninsular Florida were sampled a single time for epiphytic diatoms, and soil/water physicochemical parameters. Thirty genera, 148 species, and 26 subspecies were identified. The proportional matrices at each taxonomic level were highly similar (Mantel's r > 0.75, p < 0.0001). Autecological metrics and two sensitive or tolerant measures were developed at each taxonomic level. Wetland condition, as determined by summed metric values, was strongly correlated across taxonomic level (r2 > 0.83, p < 0.0001), and no significant difference was found when sites were placed into bins of excellent, good, fair, or poor, based on quartile scoring, for each taxonomic level. Specific conductance, soil pH, soil and water total phosphorous, and water color were significantly related to site NMDS ordination scores at each taxonomic level. This study concludes that indices of biotic integrity, when developed using autecological indices, provide similar qualitative conditional information across taxonomic levels for isolated herbaceous wetlands.
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Genetic Analysis of the Chinese Mitten Crab (Eriocheir Sinensis) Introduced to the North American Great Lakes and St. Lawrence Seaway |
09/01/2007
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TEPOLT, C. K., M. J. BLUM, V. A. LEE, AND E. D. HANSON. Genetic Analysis of the Chinese Mitten Crab (Eriocheir Sinensis) Introduced to the North American Great Lakes and St. Lawrence Seaway. JOURNAL OF GREAT LAKES RESEARCH. International Association for Great Lakes Research, Ann Arbor, MI, 33(3):658-667, (2007).
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The Chinese mitten crab (Eriocheir sinensis) is a globally invasive organism, with established non-native populations in Europe and California, USA. Since 1965, there have been sixteen confirmed catches of E. sinensis in the North American Great Lakes and their associated waterways. Analysis of sequence variation observed across a section of the mitochondrial CO1 gene for seven of these individuals (caught between 1973 and 2005) supports the hypothesis that the species has been repeatedly introduced into the Great Lakes via shipping from Europe. The species' catadromous life cycle makes it unlikely that E. sinensis will establish a breeding population in the Great Lakes proper. However, the recent discovery of two mitten crabs in the St. Lawrence River, which could be more readily colonized, underscores the risk posed by the repeated introduction of this species into the Great Lakes-St. Lawrence Seaway system.
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Quantification and Associated Variability of Induced Vitellogenin Gene Transcripts in Fathead Minnow (Pimephales Promelas) By Quantitative Real-Time Polymerase Chain Reaction Assay |
02/10/2007
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BIALES, A. D., D. C. BENCIC, R. W. FLICK, J. M. LAZORCHAK, AND D. L. LATTIER. Quantification and Associated Variability of Induced Vitellogenin Gene Transcripts in Fathead Minnow (Pimephales Promelas) By Quantitative Real-Time Polymerase Chain Reaction Assay. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 26(2):287-296, (2007).
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Ecological risk assessors have a growing need for sensitive and rapid indicators of environmental exposure in aquatic ecosystems resulting from natural and synthetic estrogen-like compounds. Investigators developing subcellular exposure markers in traditional sentinel organisms must be vigilant about inherent variability of analyses, especially regarding regulatory and policy statements. Here, we report a quantitative real-time polymerase chain reaction (QPCR) assay for the detection of vitellogenin transcripts environmentally triggered in fathead minnows (Pimephales promelas). We demonstrate that our QPCR assay exhibits little inter- or intra-assay variability (21.7 and 11.9%, respectively). This method appears to be robust in terms of variability stemming from extrinsic sources, indicating that it may be readily transferable to laboratories having the requisite equipment. Our primary focus in development of this method derived from the observation that transcriptional responses of the vitellogenin gene (vtg) in fathead minnows demonstrated high biological variability between identically treated individuals, even under controlled laboratory conditions (coefficient of variation, >100%). This variability was not seen in other genes from the same RNA preparations that we examined, suggesting that it is specific to the vitellogenin response. Our data and those of others suggest that variability in vtg expression is common to a number of aquatic vertebrates, which is indicative of genetic causation. Despite a relatively high degree of variability in vtg transcription, this method is sensitive enough to detect exposures of 5.0 ng 17 ng 17a-ethinylestradiol (EE2)/L within 24 hours of exposure and it has the ability to discriminate 10.0 from 5.0 ng EE2/L within 48 h. The vitellogenin QPCR assay is a highly sensitive, comparatively rapid, and inexpensive method for the detection and characterization of exposure to environmental estrogens and estrogen mimics.
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Screening California Surface Waters for Estrogenic Endocrine Disrupting Chemicals (Eedc) With a Juvenile Rainbow Trout Liver Vitellogenin Mrna Procedure |
07/17/2007
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DE VLAMING, V., A. D. BIALES, D. RIORDAN, D. MARKIEWICZ, R. HOLMES, P. OTIS, R. ZANDER, AND J. M. LAZORCHAK. Screening California Surface Waters for Estrogenic Endocrine Disrupting Chemicals (Eedc) With a Juvenile Rainbow Trout Liver Vitellogenin Mrna Procedure. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier Science Ltd, New York, NY, 385:66-79, (2007).
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Concern regarding the occurrence of chemicals that disrupt endocrine system functions in aquatic species has heightened over the last 15 years. However, little attention has been given to monitoring for estrogenic endocrine disrupting chemicals (EEDCs) in California's freshwater ecosystems. The objective was to screen surface water samples for estrogenic activity using vitellogenin (Vtg) mRNA quantification in livers of juvenile rainbow trout by real-time reverse transcriptase polymerase chain reaction (Q-RT PCR). Vtg mRNA analysis of livers from fish exposed to 113 ambient water samples collected from surface waters in California's Central Valley and northern area indicated that six samples (5% of total) may have contained EEDCs. The six samples induced marginal, but statistically significant, increases of Vtg mRNA. No ambient water sample evoked Vtg mRNA responses equivalent to those in positive controls (all responses were less than 2% of the positive control response). Thus, EEDC concentrations in these samples were low (at or near the threshold for the procedure) or results may have included false positives. To establish a more definitive assessment of EEDC occurrence, follow-up screening at sites where statistically significant, but weak, estrogenic activity was observed is recommended. Overall, results reveal that a majority of the California surface waters tested were below EEDC detection threshold concentration for the screening procedure utilized.
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Dna-Based Methods for Monitoring Invasive Species: A Review and Prospectus |
10/01/2007
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DARLING, J. AND M. J. BLUM. Dna-Based Methods for Monitoring Invasive Species: A Review and Prospectus. BIOLOGICAL INVASIONS. Springer Science+Business Media, 9(7):751-765, (2007).
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The recent explosion of interest in DNA-based tools for species identification has prompted widespread speculation on the future availability of inexpensive, rapid and accurate means of identifying specimens and assessing biodiversity. One applied field that may benefit dramatically from the development of such technologies is the detection, identification and monitoring of invasive species. Recent studies have demonstrated the feasibility of DNA-based tools for such important tasks as confirmation of specimen identity and targeted screening for known or anticipated invaders. However, significant technological hurdles must be overcome before more ambitious applications, including estimation of propagule pressure, and comprehensive surveys of complex environmental samples, are to be realized. Here we review existing methods, examine the technical difficulties associated with development of more sophisticated tools, and consider the potential utility of these DNA-based technologies for various applications relevant to invasive species monitoring.
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Development and Validation of a 2,000 Gene Microarray for the Fathead Minnow, Pimephales Promelas |
06/01/2007
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LARKIN, P., D. L. VILLENEUVE, I. KNOEBL, A. L. MIRACLE, B. J. CARTER, L. LIU, N. D. DENSLOW, AND G. T. ANKLEY. Development and Validation of a 2,000 Gene Microarray for the Fathead Minnow, Pimephales Promelas. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 26(7):1497-1506, (2007).
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The development of the gene microarray has provided the field of ecotoxicology a new tool to identify modes of action (MOA) of chemicals and chemical mixtures. Herein we describe the development and application of a 2,000 gene oligonucleotide microarray for the fathead minnow (Pimephales promelas), a species commonly used in ecological risk assessments in North America.
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Reach-Scale Geomorphology Affects Organic Matter and Consumer Ä13c in a Forested Piedmont Stream |
06/01/2007
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WALTERS, D., K. M. FRITZ, AND D. L. PHILLIPS. Reach-Scale Geomorphology Affects Organic Matter and Consumer Ä13c in a Forested Piedmont Stream. FRESHWATER BIOLOGY. Blackwell Publishing, Malden, MA, 52(6):1105-1119, (2007).
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We investigated the spatial and seasonal influences on δ13C variation among organic matter sources and consumers in a forested Piedmont river, South Carolina, USA.
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Collapse of a Fish Population Following Exposure to a Synthetic Estrogen |
05/22/2007
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KIDD, K. A., P. J. BLANCHFIELD, K. H. MILLS, V. P. PALACE, R. E. EVANS, J. M. LAZORCHAK, AND R. W. FLICK. Collapse of a Fish Population Following Exposure to a Synthetic Estrogen. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES. National Academy of Sciences, 104(21):8897-8901, (2007).
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Municipal wastewaters are a complex mixture containing estrogens and estrogen mimics that are known to affect the reproductive health of wild fishes. Male fishes downstream of some wastewater outfalls produce vitellogenin (VTG) (a protein normally synthesized by females during oocyte maturation) and early stage eggs in their testes, and this feminization has been attritubed to the presence of estrogenic substances such as natural estrogens, the synthetic estrogen used in birth control pills, or weaker estrogen mimics such as nonylphenol in water. Despite widespread evidence that male fishes are being feminized, it is not known whether these low-level, chronic exposures adversely impact the sustainability of wild populations. We conducted a seven year whole-lake experiment at the Experimental Lakes Area (ELA) in northwestern Ontario, Canada and showed that chronic exposure of fathead minnow (Pimephales promelas) to low concentrations of the potent EE2 led to feminization of males through the production of VTG mRNA and protein, impacts on gonadal development as evidenced by intersex in males and altered oogenesis in females, and, ultimately, a near extinction of this species from the lake. Our observations demonstrate that the concentrations of estrogens and their mimics observed in freshwaters can impact the sustainability of wild fish populations.
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Global Transcription Profiling Reveals Differential Responses to Chronic Nitrogen Stress and Putative Nitrogen Regulatory Components in Arabidopsis |
08/16/2007
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BI, Y., R. WANG, T. ZHU, AND S. ROTHSTEIN. Global Transcription Profiling Reveals Differential Responses to Chronic Nitrogen Stress and Putative Nitrogen Regulatory Components in Arabidopsis. BMC Genomics. BioMed Central Ltd, London, Uk, 8(281):1471-2164, (2007).
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Background: A large quantity of nitrogen (N) fertilizer is used for crop production to achieve high yields at a significant economic and environmental cost. Efforts have been directed to understanding the molecular basis of plant responses to N and to identifying N-responsive genes in order to manipulate their expression and enable plants to use N more efficiently. No studies have yet delineated the responses at the transcriptional levels when plants are grown under chronic N stress and the knowledge of the regulatory elements involved in N response is very limited.
Results: To further our understanding of the response of plants to varying N levels, a growth system was developed where N was the growth-limiting factor. An Arabidopsis whole-genome array was used to give a global evaluation of gene expression under different N conditions. Significantly differentially expressed genes under mild or severe chronic N stress were identified. Mild N stress only triggered a small set of genes significantly different at the transcriptional level and they were largely involved in various stress responses. Plant responses were much more pronounced under severe N stress, with a large number of significant genes identified which are involved in many different processes. Significantly differentially expressed genes were also identified after short- and long-term N availability increase. Putative N regulatory elements were identified along with several previously known motifs involved in the response to N and carbon availability as well as stress responses. We used an Arabidopsis whole genome array for a global evaluation of gene expression under different N conditions.
Conclusion: Differentially expressed genes identified provide additional insights into the coordination of the complex N responses of plants and the components of the N response mechanism. Putative N regulatory elements were identified to reveal possible new components of the regulatory network for plant N responses. A better understanding of the complex regulatory network for plant N responses will help lead to strategies to improve N use efficiency.
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A Novel Cadherin-Like Gene from Western Corn Rootworm, Diabrotica Virgifera Virgifera (Coleoptera: Chrysomelidae), Larval Midgut Tissue |
08/28/2007
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SAYED, M., E. R. NEKL, H. A. SIQUEIRA, H. MORIYAMA, R. H. FFRENCH-CONSTANT, M. BAGLEY, AND B. D. SIEGFRIED. A Novel Cadherin-Like Gene from Western Corn Rootworm, Diabrotica Virgifera Virgifera (Coleoptera: Chrysomelidae), Larval Midgut Tissue. Insect Molecular Biology. Blackwell Publishing, Malden, MA, 16(5):591-600, (2007).
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A cadherin-like gene and its mRNA were cloned from western corn rootworm (Diabrotica virgifera virgifera: Coleoptera), an economically important agricultural pest in North America and Europe. The full length cDNA (5371 bp in length) encodes an open reading frame for a 1688 amino acid polypeptide. The putative protein has similar architecture to cadherin-like proteins isolated from lepidopteran midguts that have been implicated in resistance to Bt toxins. The Diabrotica cadherin-like gene is expressed primarily in the midgut and regulated during development, with high levels of expression observed in all larval instars and adults but low expression levels observed in the pupae. The corresponding genomic sequence spans more than 75 kb and is interspersed with 30 large introns. The genomic organization of the cadherin-like gene for this coleopteran species bears strong resemblance to lepidopterna cadherins suggesting a common molecular basis for resistance to Bt toxins.
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Meteorological Influences on Algal Bloom Potential in a Nutrient-Rich Blackwater River |
11/01/2007
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Phlips, E. J., J. Hendrickson, E. L. QUINLAN, AND M. Cichra. Meteorological Influences on Algal Bloom Potential in a Nutrient-Rich Blackwater River. FRESHWATER BIOLOGY. Blackwell Publishing, Malden, MA, 52:2141-2155, (2007).
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The effect of variability in rainfall on the potential for algal blooms was examined for the St. Johns River in northeast Florida. Water chemistry and phytoplankton data were collected at selected sites monthly from 1993 through 2003. Information on rainfall and estimates ofw ater urnover rates were used in the analyses of trends in phytoplankton biomass.
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Cylindrospermopsis in Lake Erie: Testing Its Association With Other Cyanobacterial Genera and Major Limnological Parameters |
09/01/2007
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Conroy, J. D., E. L. QUINLAN, D. D. Kane, AND D. A. Culver. Cylindrospermopsis in Lake Erie: Testing Its Association With Other Cyanobacterial Genera and Major Limnological Parameters. JOURNAL OF GREAT LAKES RESEARCH. International Association for Great Lakes Research, Ann Arbor, MI, 33:519-535, (2007).
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We report the first documented observation of the potentially toxic cyanobacterium Cylindrospermopsis in lake Erie and Sandusky Bay in 2005 and quantify the physical and chemical parameters and the cyanobacterial community composition contemporaneous to its occurrence. We hypothesize that the high temperature, low light intensity, and high nutrient content of Sandusky Bay, a shallow, drowned river mouth along the southwestern shore of Lake Erie, provides an ideal habitat for Cylindrospermopsis. This is consistent with published laboratory and field studies that show these physical and chemical conditions facilitate Cylindrospermopsis growth. Using multivariate statistics, we found that Cylindrospermopsis biomass correlated with high temperatures and ahllow depths, conditions often found in Sandusky Bay. Light climate and nutrient cocentraitons were not associated with Cylindrospermopsis biomass, most likely because the light climate did not systematically change during the season and because nutrients exceeded demand. We propose that Cylindrospermopsis will increase in importance in Lake Erie, as previous research o climate change in the Great Lakes region predicts future higher water temperatures and lower water levels.
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European Green Crabs (Carcinus Maenas) in the Northeastern Pacific: Using Genetic Tools to Assess the Introduction and Regional Expansion of An Invasive Species |
03/27/2007
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DARLING, J., C. TEPOLT, M. J. BLUM, AND M. J. BAGLEY. European Green Crabs (Carcinus Maenas) in the Northeastern Pacific: Using Genetic Tools to Assess the Introduction and Regional Expansion of An Invasive Species. Presented at Puget Sound Research Conference, Vancouver, BC, CANADA, March 26 - 29, 2007.
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Oral presentation on the development and utilization of genetic tools for analyzing the spread of European green crabs (Carcinus maenas) in the eastern Pacific.
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A Comparison of Benthic Macroinvertebrate Sampling Methods on Selected Large River Tributaries to the Mississippi |
02/01/2007
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JOHNSON, B. R. AND K. A. BLOCKSOM. A Comparison of Benthic Macroinvertebrate Sampling Methods on Selected Large River Tributaries to the Mississippi. Presented at SWIMS Conference , Chicago, IL, January 30 - February 01, 2007.
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We compared three benthic macroinvertebrate sampling methods on the St. Croix, Wisconsin and Scioto Rivers in summer 2004 and 2005. EPA's newly developed, multi-habitat Large River Bioassessment Protocol (LR-BP) was compared to the multi-habitat method of the Minnesota Pollution Control Agency (MPCA) and to Hester-Dendy artificial substrates (H-D). Results indicated large differences between the LR-BP and the other sampling methods and that method differences outweighed differences among rivers. The LR-BP generally collected the most taxa and tended to include more chironomids and tolerant taxa than either the MPCA or H-D methods. In the laboratory, 500 organisms were sorted randomly from each sample and richness metric values were calculated and evaluated across a range of fixed-count subsample sizes (100 to 500 organisms). Regardless of field method, richness metrics changed little (<12%) at subsample sizes of >300 individuals, suggesting a 300 fixed count may be an appropriate level of laboratory effort for large river bioassessment. Addition of a large rare sort also increased metric values similarly among field methods, though increases were greatest for the MPCA method. Results of this study indicate that artificial substrates or richest targeted habitat approaches, such as MPCA, may underrepresent some components of the benthic community that might be valuable for biological assessment of large rivers.
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| PRESENTATION |
Development of Macroinvertebrate Indicators for Nonwadeable Tributaries to the Ohio and Mississippi Rivers |
01/31/2007
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BLOCKSOM, K. A. AND B. R. JOHNSON. Development of Macroinvertebrate Indicators for Nonwadeable Tributaries to the Ohio and Mississippi Rivers. Presented at SWIMS Conference, Chicago, IL, January 30 - February 01, 2007.
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In 2004-02005, macroinvertebrates were sampled from selected large rivers of the upper Midwest to develop appropriate assessment indicators. Macroinvertebrates, habitat and water chemistry data were collected from 132 randomly selected sites across 6 rivers with varying land cover influences. From the abiotic data collected, a principal components analysis (PCA) was used to develop a generalized stressor gradient and to select least disturbed and highly stressed sites for indicator development. Over 100 metrics were then evaluated for range, responsiveness, redundancy and variability to identify those that would best represent biological condition across sites. A multimetric index was built from a set of 7 metrics representing various aspects of the macroinvertebrate assemblage and was used to estimate condition in each river sampled. Within each river, the range of conditions tended to be quite narrow, but across rivers, a wide range of conditions was represented. The metrics and index presented provide an effective measure of biological condition in these river systems. As such, these indicators warrant further testing on their general use for assessing rivers in the Midwest.
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| PRESENTATION |
Benthic Macroinvertebrate Indicators |
01/11/2007
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BLOCKSOM, K. A. Benthic Macroinvertebrate Indicators. Presented at National Rivers Survey Workshop, San Antonio, TX, January 10 - 12, 2007.
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Presentation on macroinvertebrate sampling methods, sample processing and identification at the National Rivers Survey Workshop, January 10-12, 2007.
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| PRESENTATION |
Reach-Scale Geomorphology Affects Organic Matter and Consumer Ä 13c in a Forested Piedmont Stream |
06/04/2007
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WALTERS, D., K. M. FRITZ, AND D. L. PHILLIPS. Reach-Scale Geomorphology Affects Organic Matter and Consumer Ä 13c in a Forested Piedmont Stream. Presented at North American Benthological Society, Columbia, SC, June 03 - 07, 2007.
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We investigated seasonal (spring, autumn) and spatial variation of stream organic matter and consumer δ 13C in a Piedmont stream. Sites were sampled along a continuum and fit into two geomorphic categories: high-gradient, rock-bed ("rock") or low-gradient, sand-bed ("sand") sites. δ 13C was generally enriched in spring, but this response varied among foodweb components. CPOM, Seston, and 5 of 9 trophic guilds (e.g., grazers, insectivorous fish) showed spring enrichment, whereas FBOM and one guild were enriched in autumn. Biofilm, seston, FBOM, and 8 guilds were enriched at rock sites. δ 13C of biofilm and 4 guilds were also positively correlated with drainage area, but the magnitude of enrichment was less than between bed-types. Consumer δ 13C enrichment at rock sites suggests greater reliance on algal carbon than at sand sites; however, biofilm δ 13C was also enriched at rock sites. Thus, geomorphic differences in consumer δ 13C could be related to increased utilization of biofilm at rock sites, consumption of biofilm at rock sites that is enriched relative to biofilm at sand sites, or both mechanisms. Numerous studies have found downstream enrichment of δ 13C in stream foodwebs, but longitudinal (and seasonal) effects were minor compared with site-scale geomorphic effects in this study.
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| PRESENTATION |
Do Post-Mining Constructed Channels Replace Functional Attributes of Headwater Streams? |
06/04/2007
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FRITZ, K. M., S. FULTON, B. R. JOHNSON, C. BARTON, J. JACK, D. WORD, AND R. A. BURKE. Do Post-Mining Constructed Channels Replace Functional Attributes of Headwater Streams? Presented at North American Benthological Society, Columbia, SC, June 03 - 07, 2007.
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Mountaintop removal and valley filling is a method for mining coal in the Appalachians. Surface coal mining regulations currently recognize constructed drainage ditches associated with valley fills as compensatory mitigation. Our objective was to determine if these constructed channels are functionally equivalent to natural headwater streams. Six study watersheds were located in Robinson Forest, Breathitt County, Kentucky. Two watersheds were completely mined, two were mined but had intact ephemeral channels, and two were completely intact. Study reaches within each watershed were stratified across a hydrologic permanence gradient (ephemeral, intermittent, and perennial). Physical environment, water chemistry, litter standing crop, litter breakdown, fungal biomass, microbial respiration and litter bag macroinvertebrates were monitored from October 2005 to August 2006. Specific conductance was elevated 30-50X in mined perennial reaches. The physical environment of consturcted channels differed from that of natural channels and differences were most apparent among intermittent reaches. Litter standing crop at intact reaches was consistently higher than at mined reaches for ephemeral sites, but was not consistently different for intermittent and perennial sites. Despite strong differences in macroinvertebrate abundance within litterbags, decay rates did not differ between intact and mined reaches.
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| PRESENTATION |
Science to Inform Policy on Protection of Headwater Streams |
06/04/2007
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FRITZ, K. M. Science to Inform Policy on Protection of Headwater Streams. Presented at North American Benthological Society, Columbia, SC, June 03 - 07, 2007.
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Recent court cases concerning the definition of jurisdictional waters under the Clean Water Act have illuminated a need to better understand characteristics and functions of headwater streams (and associated riparian and wetland habitats). Research is needed to better quantify 1) spatial extent of channels and associated hydrologic connectivity; 2) cumulative influence of various headwater classes on downstream water quality; and 3) critical characteristics and functions for protection and restoration. Large-scale, high resolution maps are needed to recognize channels from surrounding landforms. Because these water bodies are widespread and abundant, a robust classification system that relfects the variation seen across spatial and temporal scales is needed for broad and local decisions. In order to identify significant nexus, research tools are needed that quantify the aggregate influence of individual headwater stream classes on water quality of downstream waterbodies. Studies must move beyond measuring pattern and process within the stream reach and toward the functional role of stream reaches wihtin the whole network. In response to these needs, USEPA's Office of Research and Development has developed a research framework, and we have begun developing maps, spatially explicit models, and indicators that best characterize the hydrologic permanence of headwater streams.
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| PRESENTATION |
Status and EPA Research on Emerging Contaminants |
01/22/2007
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LAZORCHAK, J. M. Status and EPA Research on Emerging Contaminants. Presented at Unviersity of Cincinnati Department of Biological Sciences Seminar Series, Cincinnati, OH, January 22, 2007.
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Oral presentation at the University of Cincinnati, Department of Biological Sciences seminar series, January 22, 2007.
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| PRESENTATION |
Using Molecular Indicators for the Detection of Exposure to Emerging Contaminants |
01/31/2007
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BENCIC, D. C., A. D. BIALES, AND J. M. LAZORCHAK. Using Molecular Indicators for the Detection of Exposure to Emerging Contaminants. Presented at SWIMS Conference, Chicago, IL, January 30 - February 01, 2007.
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Aquatic organisms are constantly exposed to complex combinations of natural and anthropogenic stressors. These stressors have been linked to many biological effects in aquatic vertebrates and have the potential to result in population level effects. The overall fate, as well as, the nature and extent of ecological effects of these stressors remains poorly understood. Thus, there is a clear need for the establishment and validation of biologically-based indicators of chemical exposure in aquatic ecosystems. These indicators are often rapid, sensitive, highly specific, and integrate confounding factors such as exposure duration, biological availability, and multiple stressor interactions. Therefore, they can provide a more complete characterization of aquatic exposure when compared to other more traditional methods. Here, we overview several analytical molecular methods that target multiple sub-cellular biological levels. Additionally, we highlight current projects which use a combination of laboratory- and field-based experimental systems to provide molecular indicators of exposure that are robust to the highly dynamic and complex nature of real-world exposures. These projects use environmentally-relevant compounds which are representative of several chemical classes, such as endocrine disrupting compounds (EDCs), triazines, pyrethroids, and OP pesticides. Once identified and validated, these indicators may be incorporated into ongoing monitoring efforts with minimal additional effort and improve exposure modeling and enhance risk assessment of existing and emerging contaminants in the aquatic environment. Our goal is to transfer these molecular indicators to the Program Offices, Regions, States, and Tribes so that they can be used to assess the condition and vulnerability of the Nation's aquatic ecosystems.
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| PRESENTATION |
Indicators of Hydrologic Permanence in Headwater Streams |
01/31/2007
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FRITZ, K. M. Indicators of Hydrologic Permanence in Headwater Streams. Presented at SWIMS Conference, Chicago, IL, January 30 - February 01, 2007.
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Headwater intermittent streams lie at the aquatic-terrestrial interface and represent much of our nation's stream miles. Recent court cases concerning the definition of jurisdictional waters under the Clean Water Act have illuminated a need to better understand the characteristics and function of temporary streams. The objective of our study was to identify physical and biological indicators of hydrologic permanence in forested headwater streams. A total of 113 reaches from 31 streams across 6 EPA Regions were sampled over three years. Physical habitat indicators were identified using stepwise discriminant analyses and classification and regression tree analysis. Reaches surveyed by USEPA Regional partners were held as a validation dataset for discriminant models. Perennial, intermittent, and ephemeral reaches were distinguished based on physical habitat characteristics. Drainage area, bankfull width, and the North Carolina Division of Water Quality's Stream Identification Form (modified to exclude hydrology metrics) were the most consistent measures distinguishing ephemeral from perennial reaches. Other physical characteristics (e.g., entrenchment ratio, valley slope) were most useful in discriminating intermittent from perennial reaches; however, these variables were less consistent between years. Discriminant models correctly classified 75-88% of ephemeral reaches, but only 35-50% of intermittent and 14-36% of perennial sites from the validation dataset. Five bryophyte families were identified as indicators of hydrologic permanence. The number of bryophyte taxa at ephemeral sites was significantly higher than at perennials while intermittent sites were intermediate. Invertebrate assemblages differed between perennial and intermittent reaches; however, physiographic region appears to be a stronger factor governing assemblage composition. Although further analyses are needed, these preliminary findings suggest that both physical and biological characteristics of stream reaches can be useful as regional indicators of hydrologic permanence in headwater streams.
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| PRESENTATION |
Ohio River Water Quality Assessment Using Landsat-7 Data |
02/01/2007
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FROHN, R. C. AND B. C. AUTREY. Ohio River Water Quality Assessment Using Landsat-7 Data. Presented at SWIMS Conference, Chicago, IL, January 30 - February 01, 2007.
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The objectives of this project were (1) to develop a universal index for measuring Turbidity and Chlorophyll-A from remote sensing data and (2) to correlate satellite image parameters from Landsat-7 data with field measurements of water quality for five parameters: Chlorophyll-A (Chl-A); Turbidity; Total Suspended Solids; Dissolved Oxygen; and Secchi Depth. The study area was a 95 km stretch of the Ohio River near Cincinnati, Ohio. Within this stretch, 23 samples of water quality were collected within 24 hours of a the capture of the Landsat-7 image. Two new image indices were successfully developed for estimating Chl-A and Turbidity. The Chl-A index had a 0.85 correlation and the Turbidity a 0.89 correlation with the water samples. Thirty-four other Landsat image parameters were also tested including individual bands, band ratios, principal components, and minimum noise fraction transformations but none had higher correlations than the Chl-A and Turbidity indices. Linear regression models were developed to quantify Turbidity (NTU) and Chl-A (ug/l) from the Turbidity and Chl-A indices respectively. The regression models had R2 values of 0.86 for Turbidity and 0.81 for Chl-A indicating good fits. A multiple regression model was developed for Turbidity using the Turbidity Index and five other image parameters and yielded an R2 of 0.90. Multiple regression models were also developed for Total Suspended Solids (R2 = 0.89) and Dissolved Oxygen (R2 = 0.72) using the Turbidity and Chl-A indices with other Landsat image parameters. The high correlation and simplicity of the new Turbidity and Chl-A indices indicate that they may be applicable to other rivers on a regional or national scale for rapid and cost-effective water quality monitoring.
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| PRESENTATION |
Use of Dna-Signatures and Micro-Array Analyses for Assessing Freshwater Invertebrate Biodiversity: Current Challenges and Future Promises |
06/04/2007
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HAWKINS, C. P., M. PFRENDER, P. L. HARTZELL, D. P. LARSEN, M. BAGLEY, G. COURTNEY, B. R. CREUTZBURG, J. H. EPLER, S. FEND, L. C. FERRINGTON, S. A. JACKSON, A. LEVESQUE, J. C. MORSE, M. PETERSEN, A. J. RADWELL, D. RUITER, D. SCHINDEL, AND M. WHITING. Use of Dna-Signatures and Micro-Array Analyses for Assessing Freshwater Invertebrate Biodiversity: Current Challenges and Future Promises. Presented at North American Benthological Society, Columbia, SC, June 03 - 07, 2007.
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Platform presentation at North American Benthological Society Meeting, Columbia SC, June 3-7, 2007.
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| PRESENTATION |
Determining the Minimum Number of Sites for Bioassessment of the Ohio River |
04/03/2007
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BLOCKSOM, K. A., E. EMERY, AND J. THOMAS. Determining the Minimum Number of Sites for Bioassessment of the Ohio River. Presented at Association of Mid-Atlantic Aquatic Biologists 2007 Workshop, Berkeley Springs, WV, April 04 - 05, 2007.
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For wadeable stream bioassessment, much work has been done to determine the number of samples to composite or the appropriate reach length for obtaining an adequate sample. Proportions of stream miles in a given condition are then often reported at the watershed or ecoregion level so that each stream site represents a large number of stream miles of similar type. However, in larger systems like the Ohio River, it is often more desirable to report on the number or proportion of river miles in a given condition within that particular resource. In such cases, reach length may be fixed, with the premise that a large number of shorter reaches are more useful to represent the condition of a river than a few very long reaches. We used fish data collected systematically every 2-4 miles in the late 1990s and early 2000s to determine the number of sites necessary to characterize a single pool in the Ohio River. We examined IBI-based determinations of failing/passing in each pool to determine the number of sites necessary to adequately estimate the condition within a pool while achieving a minimum level of precision. Based on the precision level desired by ORSANCO, a sampling plan was developed that included an initial 15 sites per pool, with all pools being sampled over a 5-year period. Additional sampling within a pool was only necessary if attainment or nonattainment could not be determined with the desired level of precision.
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| PRESENTATION |
Existing and Newly Developed Assessment Tools and Biocriteria for the U.S. EPA's New England and Mid-Atlantic Regions |
04/05/2007
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KLEMM, D., A. SHELTON, K. A. BLOCKSOM, AND B. C. AUTREY. Existing and Newly Developed Assessment Tools and Biocriteria for the U.S. EPA's New England and Mid-Atlantic Regions. Presented at Association of Mid-Atlantic Aquatic Biologists 2007 Workshop, Berkeley Springs, WV, April 04 - 05, 2007.
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This poster offers an overview of biological assessment programs for wadeable streams and rivers within states in the U.S. EPA Regions 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont) and Region 3 (Delaware, Maryland, Pennsylvania, Virginia and West Virginia). It provides details on target assemblages (i.e., benthic macroinvertebrates, periphyton, and/or fish) and the specific methods used by each state to determine whether biocriteria set for Aquatic Life Use (ALU) are met in wadeable streams and rivers. Since U.S. EPA Regions span state boundaries, protocols are often shared and regional approaches to bioassessment are useful. However, differences in biota due to ecoregional differences (topography, stream gradients, etc.) have made it necessary for states to adjust their monitoring and assessment programs, as well as the analysis of data and biocriteria development. There are many differences among state programs, with variations in index periods, indicator assemblages, reference conditions, sampling protocols, laboratory methods, taxonomic resolution, metric evaluation and/or index development. Differences and similarities among states are addressed for states within each of the regions.
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| PRESENTATION |
Survey of the Nation's Non-Wadeable Streams and Rivers |
03/09/2007
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FLOTEMERSCH, J. E., T. SMITH, S. G. PAULSEN, AND S. HOLDSWORTH. Survey of the Nation's Non-Wadeable Streams and Rivers. Presented at West Virginia Chapter, American Fisheries Society: Understanding Large Rivers , Morgantown, WV, March 09 - 10, 2007.
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The U.S. EPA is engaging states, tribes and other parties in designing a national survey to assess the condition of non-wadeable rivers and streams. The river survey is one of a series of surveys beng implemented as a partnership among states, tribes and U.S. EPA, with the collaboration of the U.S. Geological Survey and other organizations. The purpose of these surveys is to periodically generate statistically valid and environmentally relevant reports on the condition of the Nation's water resources. These collaborative assessments are intended to facilitate improved co-operation across jurisdictional boundaries and to enhance states' and tribes' ability to assess and manage water quality. The goal of the rivers survey is to address two key questions about the quality of the Nation's non-wadeable rivers and streams: What percent of the Nation's non-wadeable rivers are in good, fair, and poor condition for key indicators of ecological health and human activities, and what is the relative importance of key stressors such as nutrients and pathogens?
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| PRESENTATION |
Incorporation of Dna Barcodes Into Assessments of the Biological Integrity of Aquatic Ecosystems: Precision, Accuracy and Cost |
05/18/2007
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BAGLEY, M., C. SPOONER, R. KLAUDA, D. SCHINDEL, AND L. WEIGHT. Incorporation of Dna Barcodes Into Assessments of the Biological Integrity of Aquatic Ecosystems: Precision, Accuracy and Cost. Presented at European Molecular Biology Organization Workshop, Rome, ITALY, May 17 - 19, 2007.
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Historically, water quality assessments in the United States primarily focused on water chemistry assays at or near discharge sources. As it has become clear that waters also can be highly impaired from dispersed (i.e., non-point source) chemicals and non-chemical impacts, direct assays of the biological integrity of aquatic ecosystems were adopted as they reflect cumulative environmental impacts on biota. These "bioassessments" assess the incidence and abundance of fish and aquatic macroinvertebrates as indicators of aquatic ecosystem condition. Wider adoption of bioassessment protocols in governmental monitoring programs is desirable but constrained by three serious problems: (1) limited and declining taxonomic expertise for most taxa; (2) difficulty or inability to identify larval forms with high taxonomic resolution; and (3) low statistical confidence due to sample size limitations imposed by time and cost of morphological identifications. A possible solution to each of these problems is the integration of DNA barcoding into aquatic monitoring and assessment programs. We have initiated research to assess the accuracy, precision, and costs of taxonomic identifications for aquatic insects based on both DNA barcode and morphological approaches for a bioassessment program administered by the state of Maryland, USA. To directly compare DNA-based and morphological approaches, we are developing DNA barcodes for North Anerican Ephemeroptera (mayflies), Tricxhoptera (caddisflies), and Plecoptera (stoneflies), taxa which are important targets of stream bioasasessments because of their sensitivity to pollutants. A critical component of this research is the utilization of DNA barcodes to link morphologically cryptic aquatic larvae collected in streams to morphologically distinct adult voucher specimens maintained at the Smithsonian Institution. Based on our findings, we will recommend a strategy for optimal integration of DNA and morphological approaches into the state's bioassessment program that efficiently leverages available resources for specimen collection, taxonomic assessment, and data analysis. Incorporation of DNA sampling into bioassessment programs also may bring opportunities for more refined assays using population genetic models. As an example, I will show how archived DNA from bioassessments can be exploited to bring a systems understanding to aquatic ecosystem management, including identification of critical habitat necessary for metapopulation stability.
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| PRESENTATION |
Use of Geospatial Data to Predict Downstream Impacts of Coal Mining in An Appalachian Wateshed |
04/04/2007
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JOHNSON, B. R., A. HAAS, AND K. M. FRITZ. Use of Geospatial Data to Predict Downstream Impacts of Coal Mining in An Appalachian Wateshed. Presented at Association of Mid-Atlantic Aquatic Biologists, Berkeley Springs, WV, April 04 - 05, 2007.
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Our objective was to use physicochemistry collected throughout a partially mined watershed to quantify downstream influence of headwater streams using exploratory geostatistical tools. Study area was the Buckhorn Creek watershed located in the Central Appalachian ecoregion of eastern Kentucky.
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| PRESENTATION |
U.S. EPA's Survey of the Nation's Non-Wadeable Streams and Rivers |
04/04/2007
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REYNOLDS, L., J. E. FLOTEMERSCH, T. SMITH, S. G. PAULSEN, AND S. HOLDSWORTH. U.S. EPA's Survey of the Nation's Non-Wadeable Streams and Rivers. Presented at Association of Mid-Atlantic Aquatic Biologists, Berkeley Springs, WV, April 04 - 05, 2007.
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The U.S. EPA is engaging states, tribes and other parties in designing a national survey to assess the condition of non-wadeable rivers and streams. The rivers survey is one of a series of surveys being implemented as a partnership among states, tribes and U.S. EPA, with the collaboration of the U.S. Geological Survey and other organizations. The purpose of these surveys is to periodically generate statistically valid and environmentally relevant reports on the condition of the nation's water resources. These collaborative assessments are intended to facilitate improved collaboration across jurisdictional boundaries and to enhance states' and tribes' ability to assess and manage water quality. The goal of the rivers survey is to address two key questions about the quality of the nation's non-wadeable rivers and streams: what percent of the nation's non-wadeable rivers are in good, fair and poor condition for key indicators of ecological health and human activities, and what is the relative importance of key stressors such as nutrients and pathogens?
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| PRESENTATION |
Large Rivers and the Office of Water Non-Wadeable Streams Assessment |
04/10/2007
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FLOTEMERSCH, J. E., T. SMITH, S. G. PAULSEN, AND S. HOLDSWORTH. Large Rivers and the Office of Water Non-Wadeable Streams Assessment. Presented at 2007 EMAP Symposium, Washington, DC, April 10 - 11, 2007.
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Presentation on implementation of surveys of the nation's large rivers.
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| PRESENTATION |
The Emerging Issue of Pharmaceuticals and Personal Care Products in Wastewater and the Environment |
03/30/2007
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LAZORCHAK, J. M. The Emerging Issue of Pharmaceuticals and Personal Care Products in Wastewater and the Environment. Presented at 70th Annual Wastewater Operations Conference, St. Paul, MN, March 30, 2007.
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Presentation at the 70th annual Wastewater Operations Conference, Minnesota Pollution Control Agency, March 30, 2007.
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| PRESENTATION |
Emerging Contaminants What Are They? |
03/16/2007
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LAZORCHAK, J. M. Emerging Contaminants What Are They? Presented at University of North Texas Institute of Environmental Sciences Seminar Series, Dallas, TX, March 16, 2007.
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Oral presentation at the University of North Texas Institute of Environmental Sciences Seminar Series, March 16, 2007
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| PRESENTATION |
Ecosystem Services as a New Strategic Focus for USEPA's Ecological Research Program |
06/23/2007
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LINTHURST, R., I. A. GOODMAN, S. K. MARCY, W. R. MUNNS, K. SATERSON, T. J. CANFIELD, S. J. ISE-LOVELL, AND R. J. BRUINS. Ecosystem Services as a New Strategic Focus for USEPA's Ecological Research Program. Presented at U.S. Society for Ecological Economics, New York, NY, June 23 - 27, 2007.
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The USEPA's Office of Research and Development has made ecosystem services the new strategic focus for its ecological research program (ERP). Recognizing that the protection and enhancement of ecosystem services can help maintain and improve human health, economic vitality and overall well-being, the ERP will develop tools that enable planners and decision-makers at local, regional and national levels to better understand how society's choices affect the provision of these services. The ERP will use a tripartite approach to address research needs on ecosystem services. First, a set of place-based studies, conducted at watershed or regional scales, will serve as test-beds for development of analysis methods and web-based, decision-support tools. Alternative-future scenarios, reflecting local, national or global drivers of change, will be used to examine potential ecological, human-health, and economic outcomes for these locations. Quantifying the services provided by wetland ecosystems will be a second programmatic emphasis; understanding pollutant impacts on ecosystem services will be a third. These emphases will be supported by core research on ecosystem processes, modeling, and restoration. The Office of Research and Development will form partnerships with economists and health scientists, within and outside EPA, to develop approaches for quantifying services and to conduct research on valuation and restoration approaches that adequately describe the trade-offs involved. This research will be supported by a training program to better inform EPA scientists on key concepts related to ecosystem services and their valuation.
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| PRESENTATION |
Integrating Social, Economic and Ecological Analysis to Improve Wildfire Management in the U.S.: Testing a New Organizing Approach for Environmental Assessment |
06/23/2007
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BRUINS, R. J., S. BOTTI, S. BRINK, D. CLELAND, L. KAPUSTKA, D. LEE, V. LUZADIS, W. R. MUNNS, JR., N. RANA, D. RIDEOUT, M. ROLLINS, P. WOODBURY, AND M. ZUPKO. Integrating Social, Economic and Ecological Analysis to Improve Wildfire Management in the U.S.: Testing a New Organizing Approach for Environmental Assessment. Presented at U.S. Society for Ecological Economics, New York, NY, June 23 - 27, 2007.
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Conducting an integrated analysis to evaluate the societal and ecological consequences of environmental management actions requires decisions about data collection, theory development, modeling and valuation. Approaching these decisions in coordinated fashion necessitates a systematic planning process to (a) examine the nature of the environmental problem, data needs, analytical methods and decision-makers' requirements and (b) formulate an assessment approach. We describe a new, eight-step procedure for "integrated problem formulation" (IPF); this procedure brings together stakeholders and experts to examine context, values, objectives, alternatives, assessment endpoints, valuation, decision-support and effectiveness measures. We tested IPF in a workshop that examined the following problem: "How should limited public resources be allocated to minimize the risks to social welfare posed by wildfires in the U.S.?" We found that IPF broadened our understanding of the problem's scope and efficiently characterized the strengths and limitations of current wildfire management approaches. It also highlighted the importance of including experts from the decision sciences at the outset of an assessment process.
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| PRESENTATION |
Assessment of Nonwadeable Tributaries to the Ohio and Mississippi Rivers Using the Macroinverebrate Large River Bioassessment Protocol (Mlr-Bp) |
04/03/2007
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JOHNSON, B. R. AND K. A. BLOCKSOM. Assessment of Nonwadeable Tributaries to the Ohio and Mississippi Rivers Using the Macroinverebrate Large River Bioassessment Protocol (Mlr-Bp). Presented at Association of Mid-Atlantic Aquatic Biologists Annual Meeting, Berkeley Springs, WV, April 03 - 05, 2007.
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Poster presentation at the Association of Mid-Atlantic Aquatic Biologists annual meeting, April 3 - 5, 2007.
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| PRESENTATION |
Determination of Ecologically Relevant Pharmaceuticals and Their Selected Metabolites in Effluent and Surface Water Using Uplc/MS/MS |
06/05/2007
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BATT, A., M. KOSTICH, AND J. M. LAZORCHAK. Determination of Ecologically Relevant Pharmaceuticals and Their Selected Metabolites in Effluent and Surface Water Using Uplc/MS/MS. Presented at ASMS Conference on Mass Spectrometry, Indianapolis, IN, June 05, 2007.
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Objective is to develop analytical methods including SPE and UPLC/MS/MS needed to analyze over 60 human prescription pharamceuticals and metabolites belonging to a multitude of different classes in surface waters and wastewater effluent. The methods will be used in future studies to assess the impact of pharamceuticals present in WWTP discharges on the ecological health and quality of surface waters.
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| PRESENTATION |
Use of Geospatial Data to Predict Downstream Impacts of Coal Mining in An Appalachian Watershed |
06/04/2007
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JOHNSON, B. R., A. HAAS, AND K. M. FRITZ. Use of Geospatial Data to Predict Downstream Impacts of Coal Mining in An Appalachian Watershed. Presented at North American Benthological Society, Columbia, SC, June 03 - 07, 2007.
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Mountaintop removal and valley filling is a method of mining coal that results in burial of Appalachian headwater streams. Leaching of fill material often results in elevated ion concentrations below fills. A primary objective of this study was to quantify downstream extent of mining disturbance using geostatistical tools. We measured water chemistry parameters in situ throughout the partially mined Buckhorn Creek watershed, eastern Kentucky in summer 2005 and spring 2006. Sites were located 100-500 m apart and covered a maximum flow-connected distance of 25 km. Spatial dependency was modeled with empirical semivariograms utilizing asymmetric stream distance. Temperature semivariograms indicated spatial correlations of ca. 5 km. Mined tributaries produced strong confluence effects on pH and conductivity that violated assumptions of geostatistical models. A deterministic model was therefore developed to predict downstream values using measurements from tributary confluences weighted by drainage area. The model showed strong predictive ability and was robust across a large range of drainage areas and values of conductivity and pH. Such models may prove valuable to regulatory agencies in evaluating permit applications under Sections 401 and 404 of the Clean Water Act.
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| PRESENTATION |
In-Stream and Watershed Predictors of Genetic Diversity, Effective Population Size and Immigration Across River-Stream Networks |
09/03/2007
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BLUM, M. J., E. R. WAITS, M. BAGLEY, S. A. JACKSON, F. B. DANIEL, F. H. MCCORMICK, D. J. CHALOUD, AND J. M. LAZORCHAK. In-Stream and Watershed Predictors of Genetic Diversity, Effective Population Size and Immigration Across River-Stream Networks. Presented at American Fisheries Society, San Francisco, CA, September 02 - 06, 2007.
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The influence of spatial processes on population dynamics within river-stream networks is poorly understood. Utilizing spatially explicit analyses of temporal genetic variance, we examined whether persistence of Central Stonerollers (Campostoma anomalum) reflects differences in habitat quality and location within a highly modified urban watershed in southwestern Ohio, USA. While estimates of genetic diversity did not vary with habitat quality, evidence of weak but temporally stable genetic structure, location-dependent effective population sizes, and rates of immigration among sites suggest that persistence of C. anomalum within the watershed is largely attributable to source-sink dynamics driven by habitat heterogeneity. To better understand how location-dependent habitat heterogeneity may give rise to source-sink dynamics, we carried out a second study of C. anomalum in an adjacent basin to further compare estimates of genetic diversity, effective population size and rates of immigration to factors related to isolation, fine-grain and course-grain environmental variation. Mantel tests demonstrated a pattern of isolation-by-distance among sample locations, and stepwise regression identified factors associated with drainage density, isolation, fine-grain and coarse-grain environmental heterogeneity as predictor variables for estimates of effective population size and immigration rate. These results suggest that both watershed and in-stream conditions may influence population persistence, and indicate that further understanding of population dynamics within river-stream networks will likely come from additional studies that explore aspects of life history relative to spatial scale.
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| PRESENTATION |
Development of Markers of Exposure to Copper, Nonylphenol and Atrazine Using Sutractive Hybridization |
11/13/2007
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FLICK, R. W. AND J. M. LAZORCHAK. Development of Markers of Exposure to Copper, Nonylphenol and Atrazine Using Sutractive Hybridization. Presented at SETAC North America, Milwaukee, WI, November 11 - 15, 2007.
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Daphnia have been among the most commonly used test organisms for aquatic toxicity studies due to their sensitivity to contaminants. This sensitivity makes them excellent candidates for development as sentinels to monitor the occurrence of chemicals in the environment. The sequencing of the Daphnia pulex genome provides an opportunity to develop gene expression assays as indicators of exposure to sublethal concentrations of environmental stressors. In order to gauge the utility of such assays, we have produced subtraction libraries from Daphnia exposed to three chemicals that are commonly found in the environment: copper, nonylphenol and atrazine. For each of these three subtractions at least 480 clones from the forward subtraction and 480 clones from the reverse subtraction were selected for differential screening by reverse northern analyses. Based on the results of these analyses, 50 to 85 clones from each subtraction were identified as differentially expressed. Clones that exhibited the greatest differences in spot intensity were chosen for sequencing. The resulting sequences were compared to the Daphnia pulex genome database using the BLAST algorithm. A small number of candidate genes were identified for further analysis. We are in the process of generating quantitative real time PCR primers from these sequences, which we will use to verify differential expression in an independent set of exposed and control Daphnia. The development of a suite of these gene expression markers will enable us to use deployed Daphnia to diagnose the presence of contaminants in aquatic environments.
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| PRESENTATION |
Introduction of the Vitellogenin Gene in Early Life Stage Fathead Minnows as An Effective Exposure Indicator for Estrogenic Compounds |
11/13/2007
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LAZORCHAK, J. M., M. E. SMITH, D. L. LATTIER, T. V. REDDY, D. C. BENCIC, AND A. D. BIALES. Introduction of the Vitellogenin Gene in Early Life Stage Fathead Minnows as An Effective Exposure Indicator for Estrogenic Compounds. Presented at SETAC - North America, Milwaukee, WI, November 11 - 17, 2007.
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Vitellogenin (Vg) gene expression in adult male fathead minnows (FHM) has previously been used successfully to detect exposures to estrogenic compounds in aquatic systems; however, sample volume(s)required for >24h exposure durations and the logistics of sampling pose some limitations on the use of adult male fish. We have previously established that Vg is indeed expressed in larval FHM and responses were proportional to external concentration. In addition to the minimal experimental scale required to use larval fish, they are readily available, less labor intensive, economical and afford a greater number of experiments that can be performed. Early development is an exquisitely complex biologic sequence in which signaling interactions and changes in gene expression must be orchestrated in a precise spatial and temporal program to ensure that embryogenesis and pattern formation progress faithfully; therefore, a more advantageous rationale to using early developmental stages of teleosts is the would-be predictive biology arising from genomic analysis of ecological exposure. In an initial attempt to use developmental stages as a means to predict adverse outcome and develop consistent exposure biomarkers, we have developed a method for detecting exposure to estrogenic compounds in water samples using early life stage FHM. The objective set for the FHM early life stage estrogen exposure method was to establish an ideal age of larvae/juveniles that exhibited minimal variation in Vg gene expression, within groups exposed to estrogenic endocrine disrupting chemicals(EDCs)(EE2, E2, E1, and NP) and respond to the lowest levels at which adult male fathead minnows are induced to express Vg. To establish an ideal age, different stages of larvae(4,7,14,21,28,and 35 dph,in triplicate) were taken from the same larval pool. Exposures were carried out in 500 ml beakers and renewed daily. For controls, 500 ml beakers containing MHRW with the appropriate amount of DMSO (5 10 µl /L MHRW) were used. Fish were fed for 2 hours before initiation of exposure, with age adjusted amounts of newly hatched brine shrimp and exposed to test chemical(s) for 48 h. At 48 h, fish were fed again for 2 h and exposed to the respective test chemical for an additional 48h. Results will be presented on the various ages using nominal concentrations of EE2 2.5 ng/L, E2 40 ng/L, E1 60 ng/L and NP 50 ¿g/L.
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| PRESENTATION |
Non-Traditional Responses to Pharmaceuticals in Aquatic Ecosystems |
11/13/2007
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BROOKS, B., R. BRAIN, D. HUGGETT, J. M. LAZORCHAK, H. SANDERSON, J. STANLEYS, AND J. SUMPTER. Non-Traditional Responses to Pharmaceuticals in Aquatic Ecosystems. Presented at SETAC North America, Milwaukee, WI, November 11 - 15, 2007.
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Quantitation of human and veterinary pharmaceuticals in environmental matrices has resulted in pharmaceuticals in the environment receiving unprecedented attention from the scientific community. Aquatic hazard assessments often use quantitative structure activity relationships and standardized toxicity tests, which assess mortality, growth or reproduction responses following short term exposures. Although these traditional approaches are appropriate for many substances, their application to pharmaceuticals has been questioned. For example, if an aquatic criterion were developed for ethinylestradiol, an estrogen receptor agonist, or trenbolone, a synthetic androgen, following traditional approaches, the criterion for each compound could be estimated at levels several orders of magnitude higher than previously reported effect levels for fish reproduction. We examined recent reports of pharmaceutical effects to aquatic plants, invertebrates and vertebrates with a particular focus on non-standardized response variables. Several examples of these nontraditional responses include molecular and biochemical biomarkers, physiological and behavioral studies, and fish partial or full life cycle responses. If a pharmaceutical exhibits high acute-to-chronic ratio (ACR), it may chronically elicit responses through a specific mechanism of action (MOA), potentially similar to its activity in mammals. In the case of biomarkers and other non-traditional endpoints, the type of chronic response used to generate an ACR can influence whether a biomarker may be useful in the exposure and effect analysis phases of ecological risk assessment; for example, biomarkers have been historically distinguished as either indicators of exposure or effect in retrospective risk assessments. It appears that aquatic responses to pharmaceuticals that are MOA-specific and sensitive can provide indicators of exposure or effect at concentrations below those eliciting adverse responses in standardized bioassays. However, for a biomarker of effect to be useful in ecological risk assessment, its response should be directly linked to a physiologically and ecologically relevant endpoint.
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| PRESENTATION |
A Surrogate Subchronic Toxicity Test Method for Waters With High Total Dissolved Solids |
11/13/2007
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LAZORCHAK, J. M. AND M. E. SMITH. A Surrogate Subchronic Toxicity Test Method for Waters With High Total Dissolved Solids. Presented at SETAC North America, Millwaukee, WI, November 11 - 15, 2007.
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Total dissolved solids (TDS) are often identified as a toxicant in whole-effluent toxicity (WET) testing. The primary test organism used in WET testing, Ceriodaphnia dubia, is very sensitive to TDS ions, which can be problematic when differentiating the toxicity of TDS from those of other contaminants. Daphnia magna is not as sensitive to common ion toxicity as C. dubia, but is still relatively sensitive to other contaminants. We used a 4-d static-renewal survival and growth method using D. magna to help identify the toxicant in an effluent from a discharger with elevated TDS. Because of the high TDS, we needed a test organism that was sensitive to most contaminants but less so to TDS ions. We compared the sensitivity of the 4-d D. magna method to the standard, short-term chronic 3-brood C. dubia method and to the 21-d D. magna chronic study to determine its applicability in WET testing, toxicity identification evaluations (TIEs), and other toxicity testing scenarios. The statistical endpoints calculated for the 4-d D. magna study were similar to the 21-d D. magna study but were substantially higher than for the 3-brood C. dubia study. For example, the IC25s for the 4-d D. magna study, the 3-brood C. dubia study and the 21-d D. magna study were (based on chloride): 1,449 mg/L, 377 mg/L, and 2,108 mg/L, respectively. Results indicate that this test would be useful for differentiating TDS toxicity from other contaminants in TIEs and as a compliance study method for dischargers where the presence of TDS ions is an ongoing issue.
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| PRESENTATION |
Correlation and Regression |
07/11/2007
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BLOCKSOM, K. A. Correlation and Regression. Presented at Nutrients-Scientific Technical Exchange Partnership and Support Webcast, Cincinnati, OH, July 11, 2007.
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Webcast entitled Statistical Tools for Making Sense of Data, by the National Nutrient Criteria Support Center, N-STEPS (Nutrients-Scientific Technical Exchange Partnership. The section "Correlation and Regression" provides an overview of these two techniques in the context of nutrient criteria.
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| PRESENTATION |
Aquatic Ecosystem Monitoring and Assessment Across Scales |
08/28/2007
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LANE, C. R. Aquatic Ecosystem Monitoring and Assessment Across Scales. Presented at International Environmental Conference "A Healthy Amur for a Better Life", Amursk, Khabarovsk Region, RUSSIA, August 27 - September 03, 2007.
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The mission of the United States Environmental Protection Agency (USEPA) is to protect human health and the environment. As part of the Office of Research and Development within the USEPA, the Ecosystems Research Branch of the National Exposure Research Laboratory, located in Cincinnati, Ohio, conducts research under the Clean Water Act to characterize the condition of aquatic resources and responses of aquatic assemblages and ecosystem processes to anthropogenic disturbance. Methods and indicators have been or are in the process of being developed to monitor condition and characterize lakes, rivers, streams, headwater streams, and wetlands from reference settings to landscapes dominated by anthropological disturbances. The methods and indicators developed can be applied at multiple spatial and temporal scales to determine trends in aquatic condition using data from soil microbes to satellite imagery. This presentation provides an overview of the research conducted by the USEPA Ecosystems Research Branch, and will provide contact information of all the principle investigators and appropriate web sites for additional information.
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| PRESENTATION |
Wetland Inventory Using Remotely Sensed Landsat Data and Geographic Information Systems (GIS) |
08/28/2007
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LANE, C. R., M. REIF, R. C. FROHN, AND B. C. AUTREY. Wetland Inventory Using Remotely Sensed Landsat Data and Geographic Information Systems (GIS). Presented at International Environmental Conference "A Healthy Amur for a Better Life" , Amursk, Khabarovsk Region, RUSSIA, August 27 - September 03, 2007.
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Wetlands perform many functions on the landscape related to water quality and quantity, and provide habitat for myriad organisms. The identification of wetlands can be problematic, especially in areas with numerous isolated wetlands, in mixed landuse areas, or over large geographic zones. The USEPA Office of Research and Development, National Exposure Research Laboratory is working to identify and inventory wetlands using remote sensing and GIS technology, and is focusing on isolated wetland systems. Isolated wetlands, or wetlands completely surrounded by uplands, occur in many areas of the United States, often in topographic depressions. Although they are relatively common, little is known about their extent and distribution, which is essential to thoroughly understand their functions and values. Mapping techniques in GIS and Remote Sensing can provide clues to these basic questions through the examination of spatial patterns in topography, soils, hydrology, landuse/landcover, and satellite image classification. The USEPA is currently developing mapping techniques to identify and predict the locations of isolated wetlands using a 2510 km2 area in the southeastern United States for methods testing. With these new techniques, we have successfully identified isolated wetlands in the study area with >85% accuracy. Development of these methods and tools will be instrumental in mapping isolated wetlands and other wetland types across the US. The ability to accurately map wetlands will ultimately provide valuable information regarding their ecological functions and values.
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| PRESENTATION |
Development of Biological Indicators, Methods and Assessment Techniques for Headwater Streams Presentation |
07/30/2007
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FRITZ, K. M. Development of Biological Indicators, Methods and Assessment Techniques for Headwater Streams Presentation. Presented at Intermittent Streams Workshop - Advances in Monitoring for Water Quality Standards, Washington, DC, July 30 - 31, 2007.
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Oral presentation at the Intermittent Streams Workshop - Advances in Monitoring for Water Quality Standards
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| PRESENTATION |
Aquatic Sentinels Forecasting Human Exposure to Emerging Contaminants and Human Exposrue as a Predictor of Ecological Dose Response |
10/17/2007
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LAZORCHAK, J. M., D. L. LATTIER, M. KOSTICH, AND J. J. ALLEN. Aquatic Sentinels Forecasting Human Exposure to Emerging Contaminants and Human Exposrue as a Predictor of Ecological Dose Response. Presented at International Society of Exposure Analyses, Durham, NC, October 14 - 18, 2007.
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Oral presentation at ISEA Conference, Durham, NC, October 17, 2007.
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| PRESENTATION |
Future Midwestern Landscapes: A Planned Evaluation of Landscape Change and Ecosystems Ervices in the Midwestern United States |
10/18/2007
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BRUINS, R. J. Future Midwestern Landscapes: A Planned Evaluation of Landscape Change and Ecosystems Ervices in the Midwestern United States. Presented at NAS Sustainability R&D Forum, Washington, DC, October 17 - 18, 2007.
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Oral presentation at the NAS Sustainability R&D Forum, Washington, DC, October 17-18, 2007.
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| PRESENTATION |
Use of Geospatial Data to Predict Downstream Influence of Coal Mining in Appalachia |
11/08/2007
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JOHNSON, B. R., A. HAAS, AND K. M. FRITZ. Use of Geospatial Data to Predict Downstream Influence of Coal Mining in Appalachia. Presented at Mid-Atlantic Stream Restoration Conference, Cumberland, MD, November 07 - 08, 2007.
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A 2001 Supreme Court decision first called into question whether some headwater streams could be considered jurisdictional under the Clean Water Act. A subsequent decision then required that non-navigable waters must be "relatively permanent" or "possess a significant nexus" to navigable waters to be considered jurisdictional. As a result of these decisions, regulatory agencies are now faced with the challenge of accurately measuring hydrologic permanence of headwater streams and their degree of influence on the quality of downstream, navigable waters. NERL-Cincinnati is currently addressing the need for hydrologic indicators in the Headwater Intermittent Streams Study (HISS). Determination of "significant nexus" requires that stream ecologists move beyond the stream reach or habitat spatial scales where we typically operate. Novel watershed-scale study designs that incorporate measures from throughout stream networks may be a useful strategy for quantifying the downstream influence of headwater streams and to help identify "significant nexus".
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| PRESENTATION |
Do Post-Mining Constructed Channels Replace Functional Characteristics of Headwater Streams? |
11/08/2007
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FRITZ, K. M., S. FULTON, B. R. JOHNSON, C. Barton, J. Jack, D. Word, AND R. A. BURKE. Do Post-Mining Constructed Channels Replace Functional Characteristics of Headwater Streams? Presented at Mid-Atlantic Stream Restoration Conference, Cumberland, MD, November 07 - 08, 2007.
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Mountaintop mining and valley fill (MTMVF) is a method of coal mining common in eastern Kentucky and southern West Virginia. Over 1200 miles of stream channel have been buried by MTMVF. Permits for surface coal mining have recognized constructed drainage ditches associated with MTMVF as compensatory mitigation for natural stream loss. A recent court case blocked four MTMVF permits in West Virginia. Contributing to the decision was that industry and regulators do not have evidence that constructed drainage ditches effectively replace the structure and function of natural headwater streams.
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| PRESENTATION |
Research to Inform Policy on Headwater Streams: Ongoing and Future Directions |
12/12/2007
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FRITZ, K. M. Research to Inform Policy on Headwater Streams: Ongoing and Future Directions. Presented at Office of Science Policy Seminar for Office of Water, Washington, DC, December 12, 2007.
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Headwater streams are the exterior links of stream networks and represent a substantial proportion of U.S. stream miles. Alteration and loss of headwater streams have occurred without an understanding of the potential consequences to larger downstream waterbodies. Recent court cases have brought headwater streams into the forefront for regulatory agencies. In response to the needs of regional and program offrices, the Ecological Exposure Research Division has conducted several studies on headwater streams.
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| PRESENTATION |
Dna Barcodes for Assessment of the Biological Integrity of Aquatic Ecosystems |
09/18/2007
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BAGLEY, M. Dna Barcodes for Assessment of the Biological Integrity of Aquatic Ecosystems. Presented at Second International Barcode of Life Conference, Taipei, TAIWAN, PROVINCE OF CHINA, September 17 - 21, 2007.
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Water quality regulations and aquatic ecosystem monitoring increasingly rely on direct assessments of biological integrity. Because these aquatic “bioassessments” evaluate the incidence and abundance of sensitive aquatic species, they are able to measure cumulative ecosystem effects of chronic or intermittent pollutants in a way that water chemistry assays cannot. Reliance on morphological identifications has constrained greater adoption of bioassessment protocols due to limited availability of trained taxonomists, difficulty or inability to identify cryptic larval forms with high taxonomic resolution, and sample size limitations imposed by the time and cost of morphological analysis. Integration of DNA barcodes into aquatic monitoring and assessment programs provides a viable solution to each of these problems. We are comparing the accuracy, precision, and cost of taxonomic identifications based on DNA barcode and morphological approaches for an existing state (Maryland, USA) bioassessment program, focusing on aquatic insects in the families Ephemeroptera, Trichoptera, and Plecoptera. Importantly, morphologically cryptic aquatic larvae collected in streams are linked via DNA barcodes to taxonomically resolved adults vouchered at the Smithsonian Institution. Our results will be used to recommend strategies to integrate DNA and morphological approaches into bioassessment programs that optimally leverage available resources for specimen collection, taxonomic assessment, and data analysis.
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| PRESENTATION |
Selection for Resistance to the Cry3bb1 Protein in a Genetically Diverse Population of Non-Diapausing Western Corn Rootworm |
12/07/2007
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French, B., M. BAGLEY, C. Nielson, AND U. STOLZ. Selection for Resistance to the Cry3bb1 Protein in a Genetically Diverse Population of Non-Diapausing Western Corn Rootworm. Presented at Entomological Society of America, San Diego, CA, December 06 - 08, 2007.
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The western corn rootworm (WCR, Diabrotica virgifera virgifera) is a serious economic pest of corn, and historically has evolved resistance to many chemical insecticides when used to manage their populations. In 2003 the U.S. Environmental Protection Agency (EPA) approved for commercial use transgenic corn against WCR and other corn pest Diabrotica. This transgenic corn produces a crystalline protein derived from the common soil bacterium, Bacillus thuringiensis, that when ingested kills the corn rootworms. However, given the history of resistance evolution by WCR to insecticides, the EPA mandated that farmers using this transgenic corn plant 20% of their corn acreage to a non-transgenic variety that is either adjacent to or within the transgenic field. This 20% refuge is intended to delay resistance evolution in WCR and other pest Diabrotica by ensuring that Cry3Bb1 resistance does not evolve in WCR to economically damaging levels, as this will negate any positive benefits of the biotechnology. The 20% refuge as a resistance management plan is based on models of resistance evolution. These models utilize the best available information on WCR biology and Cry3Bb1 toxicity. However, critical information on the genetic basis of resistance to Cry3Bb1 in WCR is needed in order to improve the accuracy of these models. Data generated from this research will provide fundamental genetic information for WCR, allowing better parameterization of these models and more reliable model results.
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| PUBLISHED REPORT |
Red Shiner Invasion of the Upper Coosa River System: Dynamics and Ecological Consequences |
10/15/2007
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WALTERS, D. M. AND M. J. BLUM. Red Shiner Invasion of the Upper Coosa River System: Dynamics and Ecological Consequences. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-07/124 (NTIS PB-2008-101558), 2007.
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The red shiner (Cyprinella lutrensis) has been widely introduced across 11 states outside its native range, presumably through bait-bucket and aquarium releases. Its native range includes Great Plain and Central Lowland tributaries of the Mississippi River and western Coastal Plain drainages of the Rio Grande River. This species thrives under harsh conditions (e.g., low flow, high turbidity, poor water quality) and aggressively colonizes severely degraded habitats. Introduced populations spread rapidly, often displacing native Cyprinids. Red shiners readily hybridize with congeners, sometimes causing widespread displacement of native species. Hybridization is a significant threat to Southeastern Cyprinella, as red shiner hybrids have been reported for nine native taxa. NERL scientists, in collaboration with researchers at U.S. Geological Survey (USGS), The University of Georgia, and Duquesne University, conducted three related studies on the dynamics of red shiner invasion and hybridization with native blacktail shiners, C. venusta stigmatura, in the upper Coosa River System (UCRS). The overall goals of these studies were to identify environmental drivers of red shiner invasion and to determine genetic and environmental factors promoting hybridization.
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