Results of a Tracker Study Conducted Within Constructed Wetlands with Varying Cell Characteristics

2010 S.C. Water Resources Conferences - Science and Policy Challenges for a Sustainable Futur

Results of an Intensive Water Quality Study of the Middle and Lower Savannah River Basin

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

The global decline of reptiles, deja’ vu amphibians

Reptile species are declining on a global scale. Six significant threats to reptile populations are habitat loss and degradation, introduced invasive species, environmental pollution, disease, unsustainable use, and global climate change

Complement Factor H-Related Proteins CFHR2 and CFHR5 Represent Novel Ligands for the Infection-Associated CRASP Proteins of Borrelia burgdorferi

Background: One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP) which interact with complement regulator factor H (CFH) and factor H-like protein 1 (FHL1) or factor H-related protein 1 (CFHR1). In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi. Methodology/Principal Findings: To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement. Conclusions/Significance: In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi

Genome Stability of Lyme Disease Spirochetes: Comparative Genomics of Borrelia burgdorferi Plasmids

Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33–40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant

Shifts in the Amphibian Community over 30 Years at an Isolated Wetland: Has Climate Change Altered Wetland Hydrology?

Proceedings of the 2011 Georgia Water Resources Conference, April 11, 12, and 13, 2011, Athens, Georgia.Geographically isolated wetlands (GIW) constitute critically important habitat for many plant and animal species, including threatened, endangered and at-risk species. Most GIW on the southeastern Upper Coastal Plain are seasonal; i.e., not continually filled with water. Numerous pond-breeding amphibians rely on GIW for larval development and recruitment of juveniles to the population. Seasonal wetlands are particularly important to amphibians due to their complex life cycle and general need for fish-free aquatic habitat coupled with adjacent forests. Approximately 25% of the 127 salamander species in the U.S. are obligate or facultative GIW species, as are 70% of the 100+ anuran species. More than half of the anuran species in the U.S. use only GIW for breeding habitat. The secondary productivity of amphibians in GIW can be extremely high (e.g., >360,000 juveniles, >1400 kg wet biomass produced during a single breeding season). Recruitment success for these frog, toad, and salamander species is determined largely by wetland hydroperiod (the amount of time a GIW holds water). Variation in hydroperiod results from differences in wetland size and geomorphology, timing and amount of rainfall, extent of connection to groundwater, vegetation, soils, and temperature. Wetland hydroperiod is the primary determinant of which amphibian species inhabit a particular wetland, both directly (via the amount of time water is available for larval development) and indirectly (via effects on predatory and competitive interactions). Most pond-breeding amphibian species have adaptations to subsets of conditions along the hydroperiod continuum; i.e., there are ‘short-,’ ‘intermediate-,’ and ‘long-hydroperiod’ species. Climate change has the potential to exacerbate the increasingly serious problem of amphibian decline by inducing shifts in average hydroperiod, as well as “normal” pond filling and drying dates. For example, general circulation models for future climate in the Southeast predict rainfall amounts may shift from -10% to +20% from current levels, with changes in rainfall intensity and extremes also likely. Changes in precipitation and temperature regimes will likely lead to altered wetland hydroperiods at the landscape level. GIW on the Department of Energy’s (DOE) Savannah River Site (SRS) in South Carolina have been the subject of research for decades, particularly with regard to their amphibian and reptile communities, plant communities, and hydrologic variation. Forty-three species of amphibians occur on the SRS, a rich diversity in the most biodiverse region of the U.S. for amphibians; 27 of these species utilize GIW habitats. Although GIW make up only about 5% of the area of wetland and aquatic habitats on the SRS (and ~23% statewide), they are essential for the maintenance of local biodiversity. Rainbow Bay, a 1-ha seasonal wetland, has been sampled daily for herpetofauna for 32 years and is recognized by Guinness World Records as the longest running continuous study of an amphibian community in the world. Collectively, the longterm SRS studies provide some of the best data in existence relating variation in environmental variables (e.g., wetland hydroperiod) to population trends in amphibian communities. We examined the dynamics of an amphibian community over 30 years in relation to changes in environmental variables and average wetland hydroperiod. Since 1978 the average hydroperiod has decreased (F1,28 = 6.69, P = 0.01) and the average date of pond filling is later (F1,28 = 8.34, P = 0.007). During that time we observed a shift in community dominance from several longer hydroperiod species (e.g., Ambystoma talpoideum, A. tigrinum, Notophthalmus viridescens) to a few shorter hydroperiod species (e.g., A. opacum). Species changes appeared to be primarily related to drought cycles and accompanying shortened hydroperiods, which differentially affected species’ juvenile recruitment. Because water levels in GIW depend mainly on precipitation and evapotranspiration, changes in climate will produce changes in hydrologic regimes. Changes in hydroperiod dynamics of GIW across the landscape are likely to influence local (individual wetland) population persistence, as well as metapopulation dynamics by altering exchange rates of amphibians among wetlands.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources FacultyThis book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

Preliminary Data from a Comprehensive Savannah River Study: The First 6 Months

Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.Southeastern Natural Sciences Academy has initiated a two year comprehensive study to assess the upstream impacts on water quality in the Savannah River with emphasis on the Augusta urban corridor. One of the driving forces of the study is characterization of the upstream contribution of oxygen demanding substances to the Savannah Harbor. The ongoing study began in January 2006 and encompasses the physical, chemical, and biological domains of limnology. We have employed both Eulerian and Lagrangian approaches through continuous collection of data from static multiparameter probe stations and through flow based chemistry sampling events, respectively, with stations spanning from River Mile 148 (near Plant Vogtle) to River Mile 215 (above Augusta, GA). This presentation represents a portion of the first 6 months of collected Eulerian and Lagrangian data. Preliminary Eulerian results showed that, on average, temperature and conductivity increased steadily from river mile 215 to river mile 148 with the highest variability for both parameters at the downstream station. The overall trend for pH showed no net change from River Mile 215 to 148 but pH increased by nearly 1 unit at River Mile 202 and was most variable at that location. The overall trend for dissolved oxygen showed a net loss of ~0.5 mg O2/L from River Mile 215 to 148 but increased by an average of 1.5mg O2/L at River Mile 202 and remained elevated through River Mile 185. Lagrangian sampling results for the May sampling event showed that increases in conductivity from River Mile 215 to 148 mostly resulted from downstream increases in sodium, alkalinity (as CO3), sulfate, chloride, potassium, calcium, and iron. Total organic carbon, almost entirely in the dissolved phase, increased from River Mile 215 to 148. This increase was equivalent to ~700 kg C added to the river over that reach, none of which was characterized as a biologically oxygen demanding substance (BOD5) but may have been characterized as an oxygen demanding substance under harsher conditions (COD).Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors

Maternal Transfer of Contaminants and Reduced Reproductive Success of Southern Toads (Bufo [Anaxyrus] terrestris) Exposed to Coal Combustion Waste

Bioaccumulation of contaminants and subsequent maternal transfer to offspring are important factors that affect the reproductive success of wildlife. However, maternal transfer of contaminants has rarely been investigated in amphibians. We examined maternal transfer of trace elements in southern toads (Bufo­[Anaxyrus] terrestris) residing in two locations: (1) an active coal combustion waste (CCW) disposal basin and adjacent 40-ha floodplain contaminated with CCW over 35 years ago and (2) an uncontaminated reference site. Our study is among the few to document tissue concentration-dependent maternal transfer of contaminants and associated adverse effects in amphibians. We found that females collected from the CCW-contaminated area had elevated concentrations of Ni, Se, and Sr; these females also transferred elevated levels of Cu, Pb, Se, and Sr to their eggs compared to females from the reference site. Overall reproductive success, estimated as a function of clutch size and offspring viability, was reduced by 27% in clutches collected from parents from the contaminated site compared to the reference site. Offspring viability negatively correlated with female and/or egg concentrations of Se and Ni. Reproductive success negatively correlated with Se and Cu concentrations in females, and Se concentrations in eggs. Our study highlights how exposure to CCW can negatively affect amphibian reproduction