Trace elements in bivalves from the Rio Cruces, Chile, trace watershed evolution after a major earthquake and challenge a postulated chemical spill from a pulp plant
In May, 1960, the largest recorded earthquake in the history of the planet hit southern Chile, dropping part of the course of the Rio Cruces by 2m and creating an extensive wetland. The Brazilian Waterweed Egeria densa colonised the area, and became a primary food source for large populations of the Black-necked Swan, Cygnus melancoryphus. In 2004, a large pulp mill commenced operations upstream on the river. According to local reports, immediately after the opening of the plant, the weed died and the swans left. There was public outcry, and a search for a cause or a culprit. It was postulated that some sort of chemical spill from the plant caused the weed to die, resulting in departure of the swans. In 2008, we collected specimens of the bivalve Diplodon chilensis from several locations downstream from the Plant and towards the wetland to see if there was evidence of a chemical spill recorded in the shells. We prepared thin-sections of the shells to observe growth line development and patterns. Additionally, shell samples were analysed for stable oxygen isotopes and trace elements, using LA-ICP/MS. Based on annual growth lines, some of the bivalves were long-lived, with an age of more than 50 years. These individuals settled in the river shortly after the earthquake, and have lived there continuously ever since. Annual and sub-annual banding was clear, and the annual cyclicity of the major bands was verified with oxygen isotope analysis. There are no changes in growth corresponding to 2004. Trace element scans provided a wealth of information on the evolution of this earthquake-impacted wetland. Barium, Strontium and Manganese all showed strong annual cyclicity. From the analysis of older specimens, we interpret the high peaks of the Ba signal as reflecting soil erosion-Ba peaks are large immediately after the earthquake, then they diminish through time. Sr is likely a temperature signal, and Mn reflects runoff. Minor peaks in Cu, As and Pb probably reflect agricultural sprays. There is no evidence of a chemical spill in 2004, or at any time, reflected either in shell growth or trace element patterns. The disappearance of the weed has probably been due to a process of natural succession, and the Plant's opening was an unhappy coincidence. Sedimentation rates in the wetland are very high, and the environment is now less favorable to the weed.
Volcano-Sedimentary Hosted Diatomite Occurrences: Alayunt (Kutahya), West Anatolia, Turkey
Diatomite (Diatomaceous Earth or "DE") is a sedimentary rock primarily composed of the fossilized remains of unicellular fresh water plants known as Diatoms. This study presents geochemical, mineralogical and economic characteristics of the Volcano-sedimentary hosted Alayunt diatomite occurrences. Lacustrine sedimentation is the principal industrial mineral sources for the studied district. Alayunt diatomites are known as one of the important industrial mineral deposits in West Anatolia because of their significant chemical and physical nature. Representative samples were collected from the location of the deposit, at spring conditions, to examine host rock, deposition features, chemical and physical characteristics. Late Miocene-Early Pliocene aged freshwater diatomite deposit was related to lacustrine-type sedimentary processes. Observed morphology and structure at the field are the main indicator of syngenetic deposition in the lacustrine basin. Diatomite shows horizontal layers in the volcano sedimentary host rock. XRD patterns of diatomite show dominant amorphous silica with small amounts of cristobalite. SEM micro-photos indicate that Alayunt diatomites are generally composed of benthic and the rare planktonic species. Chemical data show that diatomites have high silica contents (above 85 % SiO2) and low contaminants. Results suggest that Alayunt diatomite has economic importance for industry because of favorable geological-depositional, geochemical and physical features. Diatomite consists of approximately 90% silicon dioxide, with the remainder of its contents being elemental minerals, which are essential for plant growth. All of these unique factors make Diatomite the premium horticultural grade medium for all growing applications.
Platinum Element Group and Other Metal Element Variations at the Permo-Triassic Boundary in Kashmir and British Columbia and Their Significance
The end Permian marks the greatest extinction in the geological record, but there is little consensus on whether it was caused by terrestrial or extraterrestrial factors. We report here detailed analyses of platinum group element(PGE) and other metals from relatively narrowly spaced (30 cm. in Kashmir) intervals in two expanded sections from the Permo-Triassic northern and southern hemispheres that confirm a terrestrial volcanic source for the elements. But a mechanism is required that can distribute such elements world-wide from their volcanic sources, currently only exposed in the Permo-Triassic northern hemisphere.
Sediment Core Contaminant Profiling in Site Assessment: Implications for Atmospheric Deposition of Contaminants Versus Point Source Release
Differentiating between point source industrial contamination and regional atmospheric deposition is integral to accurately implementing effective monitoring, mitigation and remediation programs. This study evaluates polycyclic aromatic hydrocarbon (PAH), lead (Pb) and mercury (Hg) profiles in sediment cores retrieved from two northern Ontario lakes. One lake (Lake A) has an industrial facility located close to the shore, while the other (Lake B) located 3 km away does not. The goal of this study was to demonstrate the use of contaminant concentration profiling in sediment cores as a tool for differentiating atmospheric versus point source industrial inputs to lake sediments. Concentration profiles for Pb, Hg and PAH from both lakes were consistent with atmospheric deposition as observed in other lakes lacking industrial sources. Hg concentrations increased from 0.18 µg/g at a depositional date of approximately 1900 to 0.26 µg/g in the uppermost sediments. Concurrently, Pb concentrations increased from 5 ug/g at a depositional date of approximately 1900 to 25 ug/g and 26 ug/g in the most recent sediment of Lakes A and B respectfully. Both of these profiles were similar to other remote lakes. The range in concentrations of individual PAHs from both lakes (0.1 ug/g to 0.17 ug/g) were also within the range of concentrations found in other remote areas, however, they were significantly lower than those observed in nearby Siskiwit Lake. This difference was explained by the configuration of regional combustion sources and prevailing wind patterns that indicated Siskiwit Lake was receiving inputs from coal fired power generation plants which do not appear to be impacting the lakes in this study. In addition, comparison of cores collected proximal to the industrial site and in the middle of the lake revealed no relationship regarding increasing concentrations with proximity to the industrial facility. Thus the observed concentrations in these sediments were concluded to be due to atmospheric deposition. However, comparison of the concentrations observed in this study with provincial standards for mercury and federal standards for mercury and PAHs in sediment showed that atmospheric deposition occurring in these lakes was sufficient to result in concentrations equal to or exceeding the guidelines. Without the use of sediment concentration profiling, these exceedances may have been erroneously attributed to adjacent industrial operations resulting in significant remediation and mitigation costs. The use of sediment core contaminant concentration profiling overcomes this possibility thus allowing more effective mitigation and remediation decisions.
Active Growing of Siliceous Stromatolites in the Lake Specchio di Venere, Pantelleria Island, Central Mediterranean
Stromatolites are laminated organosedimentary structures produced by mediation of microbial communities that constitute a peculiar coupled geo-biosphere system. These deposits represent the earliest macroscopic evidence of life in the fossil record and contain potentially important palaeoenvironmental and biologic information. Stromatolites are not necessarily carbonatic but, even if more rarely, can be siliceous and evaporitic. Occurrences of siliceous stromatolites are mostly associated to geothermal fields in Iceland, Yellowstone, New Zealand and Kenya. This research reports the discovery of siliceous stromatolites actively growing in the lake Specchio di Venere (Pantelleria Island, Sicily), an endorheic saline lake within a calderic depression. At present, volcanic activity in the island is limited to low temperature fumarolic emissions and to thermal springs characterized by temperatures up to 90°C. The stromatolites were found in a scenario of very shallow waters and pools, close to small CO2 vents. The presence of living microbial communities is highlighted by different layers (microbial mats) ranging in colour from orange-red to green to reddish-brown, at the top, middle, and bottom, respectively, of stromatolites. The present work shows preliminary results obtained by petrographic (polarizing microscope and SEM), mineralogical (X-Ray diffractometry, Fourier Transfom Infrared, Fourier Transform Raman) and geochemical investigations of the Specchio di Venere lake stromatolites. Detailed observations under the microscope and SEM highlight the presence of biofilm, microbial filaments and silica spheres organized in alveolar structures. IR and Raman analyses point out the presence of different SiO2 mineralogical phases in the sedimentary layers related to an increasing maturation of silica. The REE patterns of these samples identify a typical enrichment in HREE, in the region Tm-Yb-Lu, probably linked to microbial activity.
Geomorphology and the Distribution of Plants
Plant ecologists often describe plant distribution using a technique called gradient analysis to derive plant tolerance curves representing species performance along an environmental gradient, such as soil moisture. The shape of these curves has been a matter of some debate in the literature, as different studies have found different distributions for similar species, such as Gaussian and skewed. One element common to gradient analysis techniques has been that the structure of the terrain itself has not been acknowledged in all but the most general sense. We use a terrain evolution model to create terrains acted upon by different geomorphic processes such as soil creep, and saturation-excess runoff. We then distribute a topographic index of soil moisture across each terrain. Individual plant species represented by hypothetical Gaussian curves of species abundance along a soil moisture gradient differing in ranges, modes, and peaks, are then distributed one at a time across each terrain. Transects, defined as the path of steepest descent from individual grid cells to the channel of each digital elevation model are then randomly sampled and averaged, and the resultant distribution for each species analyzed and compared both to the original distribution and to those distributions returned from different terrains. Results show that the geomorphic processes that act within and upon terrain influence soil moisture through differences in slope, curvature, and contributing area. This in turn results in different distributions of soil moisture among terrains acted upon by different processes. The tolerance curves returned from different terrains often represent only a piece of the original curve as the full range of conditions under which the hypothetical plant can survive are either underrepresented or absent from certain terrain. Thus, the structure of the environment must be considered when deriving species tolerance curves, and analyzing species distributions.
Unravelling the Impacts of Climate and People on Vegetation Dynamics in the Sahel 1982- 2002
Satellite sensors have recently shown that much of the Sahel belt of north Africa has experienced significant increases in photosynthetic activity since the early 1980s. This has reignited old debates about the role that people play in shaping land surface status at broad geographical extents. If the human 'footprint' on Sahel vegetation dynamics is measurable, then such impacts may be significant enough alter broad-scale both carbon budgets and climate via land surface atmosphere feedbacks. We test the hypothesis that people have had a measurable impact on vegetation dynamics in the Sahel for the period 1982-2002. We accomplish this by mapping the agreement between potential natural vegetation dynamics predicted by a process-based ecosystem model (Lund Potsdam Jena-Dynamic Global Vegetation Model) and satellite-derived greenness observations (Global Inventory Modelling and Mapping Studies data set) across a geographic grid at a spatial resolution of 0.5 degrees. We then relate this agreement metric to state-of-the-art data sets on demographics, pasture, and cropping. Demographic and agricultural pressures in the Sahel are unable to account for differences between simulated and observed vegetation dynamics, even for the most densely populated areas. But we do identify a weak, positive correlation between data-model agreement and pasture intensity at the Sahel-wide level. This indicates that herding or grazing does not appreciably affect vegetation dynamics in the region. Either people have not had a significant impact on vegetation dynamics in the Sahel or the identification of a human 'footprint' is precluded by inconsistent or subtle vegetation response to complex socio-environmental interactions, and/or limitations in the data used for this study. This research showcases untapped potential for combining ecosystem process models with remote sensing at broad spatial extents for examining the underlying causes of ecosystem change.
The soil H2 uptake in a future hydrogen economy
Hydrogen as a source of energy has been proposed as the next generation of fuel that would decrease dependence on fossil fuels. Using H2 as an alternative energy source could lead to an increase in atmospheric H2 concentration above the current level of 0.55 ppm. Recent studies have proposed that the potential increase in atmospheric H2 concentration may lead to changes in atmospheric chemistry, notably that the atmospheric lifetime of methane (CH4, a potent greenhouse gas) will increase. In terms of hydrogen sinks, soil microbes currently account for about 80% of the H2 removed from our current atmosphere. A key question is whether the sink strength of soil will change with an increase in atmospheric H2 concentrations. Soil microbes would be expected to respond by increasing their number or capacity for H2 consumption. This study tests the hypothesis that H2 uptake by soils will adapt to long term exposure to elevated H2 and provide an increased feedback regulation over atmospheric H2 levels. In a laboratory study with constant soil temperature and moisture, soil was exposed to 0.5 ppm (current atmospheric), 1.4 ppm (two and half-fold enrichment) and 2.5 ppm (five-fold enrichment) H2 for 243 days. After 67 days, H2 uptake rates increase linearly in response to different H2 concentrations with a 4 and 7 fold increase in the 1.4 ppm and 2.5 ppm H2 treatment, respectively, relative to current atmospheric H2. However, at a longer term H2 exposure, a convex relationship of H2 uptake rates to H2 concentrations was found. After 8 months H2 exposure, soil showed a 7 and 10 fold increase in the 1.4 ppm and 2.5 ppm H2 treatment respectively, relative to current atmospheric H2. The active site of soil H2 uptake was found to be in the very surface soil layer, and was only active as long as soils were kept moist. This suggests that soil has a high capacity of H2 deposition, but some factor may ultimately limit H2 uptake rates in soils, and that soil may not have an infinite capacity to absorb extra H2 in the atmosphere arising from the use of H2 as an energy source.
The Role of Cyanobacteria in CO2 Sequestration at Mine Sites
The weathering of mine tailings occurs relatively rapidly as a result of their high surface area and the release of cations, such as Ca2+ and Mg2+, are then available to form stable carbonate minerals thereby sequestering CO2 . In natural environments, silicate weathering in bedrock is biogeochemically coupled to the precipitation of carbonate minerals by microorganisms. Equation 1 describes the combined processes of bedrock weathering and carbonate precipitation by oxygenic phototrophic bacteria (e.g., cyanobacteria) . (Ca,Mg)SiO3 + 2H2CO3 + H2O = (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Tailings from the Diavik Diamond Mine, Northwest Territories, Canada and Mount Keith Nickel Mine, Western Australia were leached using hydrochloric, sulfuric, acetic, nitric and phosphoric acids. These solutions were amended with nutrients and were inoculated with a consortium dominated by Synechococcus sp. from a hydromagnesite-wetland near Atlin, British Columbia Canada. Cyanobacteria are able to induce precipitation of carbonate minerals by the alkalinization of their microenvironment, concentrating cations on their cell membrane, which also provides regularly spaced, chemically identical sites for mineral nucleation [3-5]. Resulting biofilms and precipitates were examined using phase-contrast light microscopy and scanning electron microscopy. Results indicate that Synechococcus sp. may be able to mediate carbonate precipitation in waters produced from leaching mine tailings. Carbonate precipitation at mine sites could be facilitated using a specifically designed pond to collect drainage waters from mine tailings, which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially-aided carbonate precipitation could play an important role in mineral carbonation of mine tailings as part of a CO2 sequestration strategy at mine sites.  Wilson et al. (2006) Am. Mineral. 91, 1331-1341.  Ferris et al. (1994) Geomicrobiol. J. 12, 1-13.  Power et al. (2007) Geochem. Trans. 8, 13.  Thompson and Ferris (1990) Geology 18, 995-998.  Schultze-Lam and Beveridge (1994) Can. J. Micro. 40, 216-223.
Pore Water PAH Transport in Amended Sediment Caps
Capping is a common remediation strategy for contaminated sediments that creates a physical barrier between contaminated sediments and the water column. Diffusive flux of contaminants through a sediment cap is small. However, under certain hydrodynamic conditions such as groundwater potential and tidal pumping, groundwater advection can accelerate contaminant transport. Hydrophobic organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) could be transported through the cap under advective conditions. To better understand PAH migration under these conditions, physical models of sediment caps were evaluated in the laboratory through direct measurement of pore water using solid phase micro-extraction with gas chromatography and mass spectrometry. Contaminated sediment and capping material was obtained from an existing Superfund site that was capped at Eagle Harbor, Washington. A PAH dissolution model linked to an advection-dispersion equation with retardation using published organic carbon-water partitioning coefficients (Koc) was compared to measured PAHs in the sediment and cap porewater of the physical model.
Studies on Dechlorination of DDT with Alkaline 2-propanol and Iron-Nickel (Fe-Ni) Catalyst.
The Persistent Organic Pollutants (POPs) pesticides were previously extensively used in the cotton production and other agricultural activities in Pakistan and at least three thousand metric tons of obsolete pesticides have been stored under extreme hazardous conditions in more than thousand sites. Locally banned or severely restricted pesticides are easily available and DDT is continuously illegally imported and use in our country. Elimination of organochlorine pesticides (OCPs) waste has received considerable attention over the past two decades. Existing catalytic hydrodechlorinated techniques for disposing of OCPs are very costly due to the use of noble metals as catalysts. The aim of our study is to develop the cost effective and efficient method for the safe disposal of OCPs. This study is in continuation work on dechlorination of organochlorine pesticides with Fe-Ni catalyst in alkaline 2-propanol media. We turned our attention to the development of DDT disposal method for the third world countries. Herein, we report our first finding that in alkaline 2-propanol with Fe-Ni catalyst is an effective method for dechlorination of DDT. Catalytic dechlorination of DDT was carried out in an alkaline solution of NaOH and 2-propanol in the presence of catalyst at the temperature below 82 oC and end products were analyzed by using Gas Chromatography (GC-ECD) and Ion Chromatography (IC) techniques. Results obtained with initial concentration of DDT ranging between 10-100 μg/ml showed conversion of DDT to chlorine free product within 4 hrs.
Modeling Bacteria Surface Acid-Base Properties: The Overprint Of Biology
Bacteria are ubiquitous in the environment and are important repositories for metals as well as nucleation templates for a myriad of secondary minerals due to an abundance of reactive surface binding sites. Model elucidation of whole cell surface reactivity simplifies bacteria as viable but static, i.e., no metabolic activity, to enable fits of microbial data sets from models derived from mineral surfaces. Here we investigate the surface proton charging behavior of live and dead whole cell cyanobacteria (Synechococcus sp.) harvested from a single parent culture by acid-base titration using a Fully Optimized ContinUouS (FOCUS) pKa spectrum method. Viability of live cells was verified by successful recultivation post experimentation, whereas dead cells were consistently non-recultivable. Surface site identities derived from binding constants determined for both the live and dead cells are consistent with molecular analogs for organic functional groups known to occur on microbial surfaces: carboxylic (pKa = 2.87-3.11), phosphoryl (pKa = 6.01-6.92) and amine/hydroxyl groups (pKa = 9.56-9.99). However, variability in total ligand concentration among the live cells is greater than those between the live and dead. The total ligand concentrations (LT, ýmol- mg-1 dry solid) derived from the live cell titrations (n=12) clustered into two sub-populations: high (LT = 24.4) and low (LT = 5.8), compared to the single concentration for the dead cell titrations (LT = 18.8; n=5). We infer from these results that metabolic activity can substantively impact surface reactivity of morphologically identical cells. These results and their modeling implications for bacteria surface reactivities will be discussed.
Microbial Response in Peat Overlying Kimberlite Pipes in The Attawapiskat Area, Northern Ontario
Exploration for ore deposits occurring under thick, post-mineralized cover requires innovative methods and instrumentation . Buried kimberlite pipes 'produce' geochemical conditions such as increased pH and decreased Eh in overlying peat  that intuitively select for bacterial populations that are best able to grow and, which in turn affect the geochemistry producing a linked signal. A microbiological study of peat was conducted over the Zulu kimberlite in the Attawapiskat area of the James Bay Lowlands to determine if the type of underlying rock influences the diversity and populations of microorganisms living in the overlying peat. Peat was sampled along an 800 m transect across the Zulu kimberlite, including samples underlain by limestone. Microbial populations and carbon source utilization patterns of peat samples were compared between the two underlying rock types. Results demonstrate an inverse relationship of increased anaerobic populations and lower biodiversity directly above the kimberlite pipe. These results support a reduced 'column' consistent with the model presented by Hamilton . The combination of traditional bacterial enumeration and community- level profiling represents a cost-effective and efficient exploration technique that can serve to compliment both geophysical and geochemical surveys.  Goldberg (1998) J. Geochem. Explor. 61, 191-202  Hattori and Hamilton (2008) Appl. Geochem. 23, 3767-3782  Hamilton (1998) J. Geochem. Explor. 63, 155-172
Refining global mapping of foliage clumping index and leaf area index with multi-angular POLDER 3 measurements: validation and topographic compensation
The clumping index quantifies the level of foliage grouping within distinct canopy structures, such as tree crowns, shrubs, and row crops, relative to a random distribution. In addition to the effective leaf area index retrieved from mono-angle remote sensing, vegetation foliage clumping is a critical new source of information for advanced modelling of radiation interaction with vegetation and energy and mass (water and carbon) exchanges between the surface and the atmosphere. Clumping index can be derived from the angular signature of the reflectance at the hotspot, when the sun and view angles coincide, and at the dark spot, where the reflectance is at its minimum. The relationship was previously used to derive a first ever global clumping index map at 6 km by 6 km resolution using multi-angular POLDER 1 satellite data. The original POLDER 1 global clumping map had several limitations that are removed in this study. The addressed drawbacks are a limited spatial coverage, topographic effects, and a lack of direct validation with field measurements. First, global coverage is expanded, particularly over North America and North Asia, by integrating new, complete year-round observations from POLDER 3. Next, we show that terrain-induced shadows can enhance BRDF variation and bias negatively the clumping index (i.e. more clumped vegetation than in reality) in hilly regions. Using a global higher resolution DEM, a topographic compensation function is devised to correct for the terrain effect. The clumping index reductions can reach up to 30%, depending on terrain complexity and land cover type. The new global index map is then validated with an assembled set of over 50 different site field measurements of clumping index, covering four continents and diverse biomes. The results show that the POLDER-derived clumping index values integrate the effect of vegetation clumping both at the scales larger and smaller than a shoot - values that can be obtained only by separate measurements in the field so far. Our new vegetation clumping map has been used to improve global mapping of leaf area index and net primary productivity. Keywords: multi-angle remote sensing, vegetation clumping index, POLDER, topographic compensation
Bacterial and Fungal Activities of Northern Peatland Ecosystems
High latitude peatlands play a unique role in global climate through the long-term net sequestration of atmospheric carbon dioxide in organic soils. Fungi and bacteria dominate microfloral communities in soils and typically are responsible for the majority of direct organic matter decomposition and mineralization, yet each of these groups of microorganisms, with physiological and metabolic differences, potentially plays unique roles in nutrient and carbon cycling in soils. The ability to characterize fungal v bacterial decomposition in peatlands is therefore exceptionally important to understand and predict peatland carbon dynamics, particularly under changing environmental conditions. Here, we demonstrate for the first time, the potential of applying the glucose induced selective inhibition technique, previously used in partitioning bacterial and fungal respiration in forest and agricultural systems, to peatland soils. Using 3 ecologically and hydrologically diverse and spatially dispersed peatlands ranging from a bog to a rich fen, we demonstrated a slight bacterial dominance in a bog and a poor fen both with acidic and primarily Sphagnum peat and a strong bacterial dominance in a near pH neutral, wetter rich fen with sedge peat. This is interesting, as it was expected that microbial respiration in the surface peat profile would be dominated by fungi owing to the acidic and better drained conditions, as is the case with upland riparian forest soils. Furthermore, the maximum non-target inhibition was only 20%, indicating that the SI approach in organic wetland soils works as well as, or better than in, many upland agricultural and forest soils. As the overall importance of fungal and bacterial activities in peatland carbon cycling is still not fully understood, further applications of this technique can develop our understanding of microbial activity in peatland soils.
Formations of Bacteria-like Textures by dynamic reactions in Meteorite and Syntheses
1. Introduction Spherule texture can be formed in dynamic reaction during meteoritic impact in air. However, there are no reports on nano-bacteria-like (i.e. spherule-chained) textures with iron (and Nickel) oxides (with chlorine) in composition and micro-texture with 100nm order  in meteorite and synthetic experiment. The purpose of the present study is to elucidate spherule-chained texture with micro-texture of 100nm in order found in the Kuga iron meteorite, Iwakuni, Yamaguchi, Japan, and its first artificial synthesis in laboratory. 2. Two textures in the Kuga meteorite: The Kuga iron meteorite found in Kuga, Iwakuni, Yamaguchi, Japan reveals spherule-chained texture with Fe, Ni-rich composition with 10μm in size, where each spherule contained "long micro-texture in 100nm in size"[1,2]. The complex texture of flow and chained shapes can be found only in the fusion crust of the meteorite formed by quenched and random processes with vapor-melting process in air of the Earth. The FE-ASEM with EDX analyses by an in-situ observation indicate that the matrix of the spherule-chained texture with Fe, Ni, O-rich (with minor Cl) composition is carbon-rich composition formed by impact reactions in air. 3. Comparison with Martian meteorite Remnant of life in ocean can be found by mineralized fossil, which can be found in the Martian meteorite ALH84001 as bacteria-like chained texture of magnetite in composition (in 100nm order) around carbonate spherules . Similarity of bacteria-like texture of the ALH84001 compared with the Kuga meteorites in this study are composition of Fe-rich, C-bearing, and chained texture of small size replaced by Fe and O-rich composition in air. Major difference of these textures is no carbonates minerals in the Kuga meteorite at dynamic reaction in air [1, 2, 3]. 4. First synthesis of bacteria- like akaganeite: A bacteria-like texture with Fe oxides (with minor chlorine as akaganeite-like compositions) is synthesized by chlorine and water fixings on iron plates at author's laboratory . 5. Summary 1) Spherule- chained texture with Fe, Ni and Cl has been obtained at the fusion crust of the Kuga iron meteorite found in Japan. 2) As the Kuga iron meteorite is different with the Martian meteorite ALH84001 with composition and formation steps, bacteria-like texture of the Kuga meteorite is first significant example to form fossil-like texture by dynamic reaction of materials in the Solar System. Acknowledgements Author thanks to Dr. T. Kato, Yamaguchi University, for interpretation on bacteria-like texture. References:  Miura Y.(2008) 5th AOGS (Asia- Oceania Geosciences Society) Annual Meet. (Busan, Korea), CD#PS07- ST31-A22.  Miura Y.(2008). Meteoritics & Planetary Science (USA), 43-7, #5203.  McKay D.S. et al. (1996): Science, 273, 924-930. Miura Y. (2009): 6th AGOS (submitted )
Spatial and temporal dynamics of stream chemistry in a northern forest watershed.
Spatial dynamics of solute chemistry and natural abundance isotopes of nitrate (15N and 18O) were examined in six locations and at the watershed outlet in 2001 and 2002 in a forest watershed in the Adirondack Mountains of New York State, U.S.A. Temporal dynamics were examined during five discharge periods: winter, snowmelt, spring, summer, and fall, based on discharge levels at the watershed outlet. Solute concentrations were variable across space and time with significant (píÜ0.05) interaction effects. Year*period was significant for pH, NO3-, total N, DOC, and total Al suggesting that inter-annual variability in discharge levels was more important for these solutes than intra-annual variability. Period*sampling point was significant for pH, Mg2+, Ca2+, sum of base cations, Si, and total Al suggesting that the differences in concentration of these solutes among sampling points were moderated by discharge levels. In general, groundwater sources located in upper watershed controlled stream chemistry at higher elevations with highest pH, Ca2+, sum of base cations, Si, SO42- concentrations, with higher values in summer, and dilution effects during snowmelt. Two low elevation wetlands had a substantial influence over stream chemistry at those locations contributing lowest NO3- and highest DOC. Snowmelt exhibited among the lowest pH, sum of base cations, and SO42-, and highest NO3-, total N, and total Al; snowmelt appeared to dilute groundwater, and flush stored soil-derived solutes. Summer discharge, composed mainly of groundwater, exhibited the lowest flow, among the highest Mg2+, Ca2+, and lowest DON, DOC, and total Al concentrations. Isotopic analysis indicated that NO3- was microbial with primary source in upper watershed soil, from where it was flushed to stream under high discharge-conditions, or drained to groundwater which became its secondary source when discharge was less. Watershed outlet did not exhibit specific solute levels found at source-areas, but represented solute dynamics in the rest of the watershed well.
The Role of Highly Unsaturated Fatty Acids in Aquatic Food Webs
Highly unsaturated fatty acids (HUFAs) are important molecules transferred across the plant-animal interface in aquatic food webs. Defined here as carbon chains of length 18 (carbons) or more, with a double bond in the third (Omega 3) or sixth (Omega 6) bond from the methyl end, HUFAs are formed in primary producers (phytoplankton). With limited abilities to synthesize de novo, consumers and higher trophic organisms are required to obtain their HUFAs primarily from diet. Bioconversion of HUFAs from one form to another is in theory possible, as is synthesis via elongation and the transformation of a saturated to highly saturated fatty acid, but the enzymes required for these processes are absent in most species. HUFAs are hypothesized to be somatic growth limiting compounds for herbivorous zooplankton and have been shown to be critical for juvenile fish growth and wellbeing. Zooplankton tend to vary their fatty acid concentrations, collection strategies and utilization methods based on taxonomy, and various mechanisms have been suggested to account for these differences i.e., seasonal and nervous system hypotheses. Considering also the facts that copepods overwinter in an active state while daphnids overwinter as resting eggs, and that copepods tend to accumulate Docosahexaenoic acid (DHA) through collection and bioconversion, while daphnids focus on Eicosapentaenoic acid (EPA), one can link high DHA concentrations to active overwintering; but both EPA and DHA have similar melting points, putting DHA's cold weather adaptation abilities into question. Another characteristic setting copepods apart from daphnids is nervous system complexity: copepod axons are coated in thick myelin sheaths, permitting rapid neural processing, such as rapid prey attack and intelligent predator avoidance; DHA may be required for the proper functioning of copepod neurons. Recent modeling results have suggested food webs with high quality primary producers (species high in HUFAs, i.e. diatoms), at their base can attain inverted biomass distributions with efficient energy transfer between trophic levels, making HUFA pathways in aquatic food webs of special interest to fisheries and environmental managers. Built on our previous work, which implicitly considered HUFAs through a proxy (generic food quality term, which also indexes ingestibility, digestibility and toxicity), our aim is to elucidate the underlying mechanisms controlling HUFA transport through the lower aquatic food web, with an emphasis on the hypothesized somatic growth limiting potential. A biochemical submodel coupled to a plankton model has been formulated and calibrated, accounting explicitly for the omega 3 and omega 6 families of fatty acids; specifically, Alpha Linoleic acid (ALA, a precursor to EPA), EPA and DHA. Further insights into the role of HUFAs on food web dynamics and the subsequent implications on ecosystem functioning are gained through bifurcation analysis of the model. Our research aims to elucidate the existing gaps in the literature pertaining to the role and impact of HUFAs on plankton dynamics, which have traditionally been thought to be driven by stoichiometric ratios and limiting nutrients. In this study, we challenge the notion of nutrients being the primary driving factor of aquatic ecosystem patterns by introducing a modeling framework that accounts for the interplay between nutrients and HUFAs.
Watershed Management and Mercury Biogeochemical Cycling in Lake Zapotlan, Mexico
Lake Zapotlan is an endorheic subtropical eutrophic lake located in Jalisco State, Mexico. The lake supports a small but important local fishery for carp (Cyprinus sp.) and tilapia (Oreochromis sp.) and is an internationally recognized RAMSAR site. Very little research exists in these regions regarding mercury biogeochemical cycling. The lake receives considerable untreated municipal wastewater discharge that is elevated in inorganic total mercury (250-800 ng Hg/L) and organic methylmercury (3-10 ng CH3Hg+/L). The lake is also located on an active fault zone near an active volcano which may cause natural mercury enrichment. To assess a mercury risk to the commercial fishery we investigated the distribution of total inorganic mercury and organic methylmercury in waters, sediments, and fish tissues of the lake, surrounding wetlands, and incoming waters. Although there were high concentrations of inorganic mercury entering the lake in wastewater and seasonal tributary stream flow inputs, average concentrations in lake surface waters (3 ng Hg/L) and sediments (50 ng Hg/gdw) were relatively low. Average concentrations of total inorganic mercury were an order of magnitude higher in water (70 ng Hg/L) and sediment (245 ng Hg/gdw) in wetlands receiving the wastewater discharges. Mercury loading to the main body of the lake is likely reduced by these wetland buffer zones which allow mercury bound to particulate matter to settle out. A similar pattern was seen with respect to methylmercury concentrations. Average concentrations of methylmercury in lake surface water (below detect) and sediment (0.1 ng/gdw) were lower than in impounded wetlands (1 ng CH3Hg+/L, 0.7 ng CH3Hg+/gdw). Mercury concentrations in tilapia (3.5 ng/g) and carp (8 ng/g) from the commercial catch were found to be low in mercury; likely due to a combination of physiological, biogeochemical, and ecological factors.
Dissolved Organic Nitrogen Dynamics in Forested Catchments on the Precambrian Shield
We present preliminary data on nitrogen (N) mass balances for eleven forested catchments on the southern Ontario Precambrian Shield. Meteorological parameters, stream flow, precipitation and stream chemistry have been monitored since 1980-81. We focus on the most recent decade (1998 to 2008) and attempt to determine whether or not there are changes to N dynamics. In particular, we test whether changes have occurred to the concentrations, fluxes and percent of N species (NO3-, NH4+ and dissolved organic nitrogen (DON)) in precipitation and stream export. We also estimate the amount of N retained within forest stands and soils and test for changes in the rate of catchment scale N leaching. We place particular emphasis on patterns observed between catchments with differing amounts of wetland cover. As DON is the primary form of N exported from these catchments, we determine the relative age of stream DON. By examining the 15 N of soil organic matter within horizons of upland and wetland soils, we establish the extent to which organic forms of N are re-cycled within the catchment prior to being exported into the streams. We characterize soil organic N and DON to determine the proportion of proteinaceous material, amino sugars, and heterocyclic N. Both age and molecular composition may help reveal the primary source of DON. Currently it is unclear what proportion of DON is the product of fresh litter decomposition or aged soil organic matter. The export of stream DON is generally closely linked to dissolved organic carbon (DOC). However there is some evidence of seasonal de-coupling. We also identify changes to DOC:DON with movement through a catchment from throughfall, to soil and stream waters.
Relationship Between Hydrologic Connectivity of Phosphorus Source Areas to Lakes and the Occurrence of Cyanobacteria in Forested Landscapes
In unmanaged lakes, where there are no obvious point sources of phosphorus (P) loading, little is known about controls on formation of cyanobacteria blooms. This study contributes to our understanding of P controls on cyanobacteria blooms by building a landscape perspective of P sources and transport to lakes and relating this to cyanobacteria occurrence in lakes. Wetlands are P stores and may influence P loading to lakes. We hypothesize that landscapes with a large proportion of wetlands that are hydrologically connected to lakes via surface flow pathways will have a higher probability of cyanobacteria bloom formation compared to landscapes with little to no hydrologically connected wetlands. We test this hypothesis in natural forested landscapes in the Algoma Highlands of Central Ontario characterized by glaciated lakes in the Canadian Shield. We quantified the proportion of wetlands and their hydrologic connectivity via surface flow pathways to a lake and relate this to estimates of the origin and concentration of P within the lake, and in turn the structure and function of the microbial community in the euphotic zone of the lake. The microbial community was characterized using emerging techniques in flow cytometry and FlowCAM imagery. This study paves the way for improving our ability to predict where cyanobacteria blooms are likely to occur, particularly with altered hydrologic flow regimes as a result of climate change.
Development Of Remote Sensing And GIS Based Information System For Village Level Planning - A Case Study Of Addanki Mandal, Prakasam District, Andhra Pradesh, India