Geomicrobiology of Ferromanganese Deposits in Caves of the upper Tennessee River Basin

Ferromanganese deposits in epigenic cave systems located within the Knox Dolomite bedrock formation of the upper Tennessee River Basin were analyzed to determine the role of microbes in the cycling of manganese and the transformation of cave mineralogy. Results from geochemical analyses, molecular surveys, and culture-dependent surveys indicate that Mn(II)-oxidizing bacteria are abundant and environmentally relevant members of ferromanganese deposits in the study area, and that these cave systems harbor unique microbial communities. Over the duration of the study period (July 2009-2011), a decline in the intensity of ferromanganese deposits in a cave biofilm was noted. Because a sewage discharge may have occurred at this site prior to July 2009, it was hypothesized that the decline may have been associated with the gradual abatement of an acute, point source of pollution. The change in biofilm appearance combined with water chemistry data and molecular-based and culture-dependent results suggest an association between the bloom of Mn(II)-oxidizing bacteria and a nutrient loading event. More work is needed to determine if blooms of Mn(II)-oxidizing bacteria are widespread where contamination is prevalent. However, if this hypothesis is validated, monitoring of Mn-oxidizing microbial communities would provide a method of assessing anthropogenic impact in shallow cave systems

New Distribution Records for Minnesota Odonata

Several Minnesota state record Odonata, Aeshna subarctica, Ophiogomphus anomalus, Stylogomphus albistylus, Stylurus scudderi, and Coenagrion interrogatum are reported, along with notes on the distribution and habitat of Aeshna sitchensis. New county records for Minnesota Odonata are also reported

Mn(II)-oxidizing Bacteria are Abundant and Environmentally Relevant Members of Ferromanganese Deposits in Caves of the Upper Tennessee River Basin

The upper Tennessee River Basin contains the highest density of our nation's caves; yet, little is known regarding speleogenesis or Fe and Mn biomineralization in these predominantly epigenic systems. Mn:Fe ratios of Mn and Fe oxide-rich biofilms, coatings, and mineral crusts that were abundant in several different caves ranged from ca. 0.1 to 1.0 as measured using ICP-OES. At sites where the Mn:Fe ratio approached 1.0 this represented an order of magnitude increase above the bulk bedrock ratio, suggesting that biomineralization processes play an important role in the formation of these cave ferromanganese deposits. Estimates of total bacterial SSU rRNA genes in ferromanganese biofilms, coatings, and crusts measured approximately 7×107–9×109 cells/g wet weight sample. A SSU-rRNA based molecular survey of biofilm material revealed that 21% of the 34 recovered dominant (non-singleton) OTUs were closely related to known metal-oxidizing bacteria or clones isolated from oxidized metal deposits. Several different isolates that promote the oxidation of Mn(II) compounds were obtained in this study, some from high dilutions (10–8–10–10) of deposit material. In contrast to studies of caves in other regions, SSU rRNA sequences of Mn-oxidizing bacterial isolates in this study most closely matched those of Pseudomonas, Leptothrix, Flavobacterium, and Janthinobacterium. Combined data from geochemical analyses, molecular surveys, and culture-based experiments suggest that a unique consortia of Mn(II)-oxidizing bacteria are abundant and promoting biomineralization processes within the caves of the upper Tennessee River Basin

Mn(II)-Oxidizing Bacteria Are Abundant And Environmentally Relevant Members Of Ferromanganese Deposits In Caves Of The Upper Tennessee River Basin

The upper Tennessee River Basin contains the highest density of our nation’s caves; yet, little is known regarding speleogenesis or Fe and Mn biomineralization in these predominantly epigenic systems. Mn:Fe ratios of Mn and Fe oxide-rich bio?lms, coatings, and mineral crusts that were abundant in several different caves ranged from ca. 0.1 to 1.0 as measured using ICP-OES. At sites where the Mn:Fe ratio approached 1.0 this represented an order of magnitude increase above the bulk bedrock ratio, suggesting that biomineralization processes play an important role in the formation of these cave ferromanganese deposits. Estimates of total bacterial SSU rRNA genes in ferromanganese bio?lms, coatings, and crusts measured approximately 7×107–9×109 cells/g wet weight sample. A SSU-rRNA based molecular survey of bio?lm material revealed that 21% of the 34 recovered dominant (non-singleton) OTUs were closely related to known metal-oxidizing bacteria or clones isolated from oxidized metal deposits. Several different isolates that promote the oxidation of Mn(II) compounds were obtained in this study, some from high dilutions (10–8–10–10) of deposit material. In contrast to studies of caves in other regions, SSU rRNA sequences of Mn-oxidizing bacterial isolates in this study most closely matched those of Pseudomonas, Leptothrix, Flavobacterium, and Janthinobacterium. Combined data from geochemical analyses, molecular surveys, and culture-based experiments suggest that a unique consortia of Mn(II)-oxidizing bacteria are abundant and promoting biomineralization processes within the caves of the upper Tennessee River Basin

Iron and other transition metals in Patagonian riverborne and windborne materials: Geochemical control and transport to the southern South Atlantic Ocean

The bulk of particulate transition metals transported by Patagonian rivers shows an upper crustal composition. Riverine particulate 0.5 N HCl leachable trace metal concentrations are mainly controlled by Fe-oxides. Complexation of Fe by dissolved organic carbon (DOC) appears to be an important determinant of the phases transporting trace metals in Patagonian rivers. In contrast, aeolian trace elements have a combined crustal and anthropogenic origin. Aeolian materials have Fe, Mn, and Al contents similar to that found in regional topsoils. However, seasonal concentrations of some metals (e.g., Co, Pb, Cu, and Zn) are much higher than expected from normal crustal weathering and are likely pollutant derived. We estimate that Patagonian sediments are supplied to the South Atlantic shelf in approximately equivalent amounts from the atmosphere (30 106 T yr1) and coastal erosion (40 106 T yr1) with much less coming from the rivers (2.0 106 T yr1). Low trace metal riverine fluxes are linked to the low suspended particulate load of Patagonian rivers, inasmuch most of it is retained in pro-glacial lakes as well as in downstream reservoirs. Based on our estimation of aeolian dust fluxes at the Patagonian coastline, the high nutrient-low chlorophyll sub Antarctic South Atlantic could receive 1.0 to 4.0 mg m2 yr1 of leachable (0.5 N HCl) Fe. Past and present volcanic activity in the southern Andes—through the ejection of tephra—must be highlighted as another important source of Fe to the South Atlantic Ocean. Based on the 1991 Hudson volcano eruption, it appears that volcanic events can contribute several thousand-fold the mass of “leachable” Fe to the ocean as is introduced by annual Patagonian dust fallout

Giemsa versus acridine orange staining in the fish micronucleus assay and validation for use in water quality monitoring

This study concerns a comparative analysis of the acridineorange and Giemsastaining procedures for the fish erythrocyte micronucleusassay. The goal was to optimize the assay in the context of field watermonitoring. Fish (Carassius carassius) were exposed to a reference genotoxic agent, cyclophosphamide monohydrate 5 mg l−1 for 2, 4, and 6 days before testing. Slides from each individual were scored using the two procedures. The results show that the assay was more sensitive when acridineorange was used. When slides were Giemsa stained, the presence of ambiguous artefacts, leading to false positives and increasing random variance, reduced the contrast between exposed and control samples. AcridineOrangestaining was then applied in the context of waterqualitymonitoring. Fish were exposed for 4 days to water sampled in two hydrological contexts: basal flow and spring flood. The results show that exposure to spring flood water in an agricultural stream can induce mutagenicity

Pentatomidae (Hemiptera: Heteroptera: Pentatomidae) Captured on Purple Prism Traps Deployed for Detection of Emerald Ash Borer (Agrilus planipennis) (Coleoptera: Buprestidae) in Minnesota

The observation of bycatch from insect trapping programs, though often considered bothersome, may hold value for ecological and taxonomic studies. In Minnesota, a large trapping survey consisting of pheromone-baited purple prism traps, has been conducted for early detection of Agrilus planipennis, the emerald ash borer. Stink bugs (Heteroptera: Pentatomidae), which are pests of increasing importance in the North Central U.S., were observed to be captured by these traps. The objective of this study was to use trap bycatch from the A. planipennis traps for further documentation of the abundance and diversity of Pentatomidae in Minnesota. In 2011 and 2012, 4,401 and 5,651 purple prism traps were deployed and checked in Minnesota, respectively. Across both years, a total of 17 species of Pentatomidae were identified from 2 subfamilies, Asopinae and Pentatominae. The most abundant and prevalent species collected were Banasa calva (Say), B. dimidiata (Say), Chinavia hilaris (Say), Euschistus tristigmus luridus Dallas, Menecles insertus (Say), and Podisus maculiventris (Say). The pentatomid community observed on purple prism traps deployed in arboreal habitats differed from pentatomid communities reported in Minnesota crops (i.e., soybean, wheat and corn). Results of this study show that many pentatomid species are captured on purple prism traps and therefore bycatch of these traps could provide valuable information on the pentatomid community. However, purple prism traps should be used in addition to traditional surveillance or scouting methods for pentatomids

Decline in Relative Abundance of Hippodamia convergens (Coleoptera: Coccinellidae) in Fall Shoreline Aggregations on Western Lake Superior

In the 1970s, migratory coccinellid aggregations on western Lake Superior shorelines consisted of over 90% Hippodamia convergens Guérin-Méneville. In 2014, the alien Harmonia axyridis (Pallas) accounted for over 80% of shoreline coccinellid aggregations and H. convergens declined to less than 10% of the total. Additional work is needed to elucidate the extent and cause of the decline of H. convergens in western Lake Superior shoreline aggregations

THE REMOVAL OF ARSENIC FROM AQUATIC SYSTEMS BY IRON OXYHYDROXIDES

Surveys of dissolved Fe, Mn and As in the River Tamar, Devon, indicated general removal from the water column at low salinities. Manganese and As showed evidence of remobilisation at higher salinities. Total and non-detrital sediment extracts confirmed a remobilisation chemistry for Mn and non-detrital As, and a redox couple between Mn and As was considered. Spatial-temporal analysis of sediment data indicated both physical and chemical processes were involved in the estuarine transport of these elements. Studies of synthetic and natural Fe precipitates indicated that speciation of the Fe source and temperature of formation influenced the surface area and nature of the precipitate formed. The presence of non-authigenic Fe coatings on sedimentary particles was demonstrated. Chemical models of synthetic and natural Fe oxyhydroxides were used to study As adsorption as a function of pH, temperature and precipitate age. Uptake of As (V) onto fresh Fe (III)-derived material was rapid and related to precipitate formation. Adsorption by fresh Fe (II) precipitates was pH dependent in freshwater and in seawater followed two kinetic regimes. Adsorption was 1st order at pH 7.6, where the adsorption process was rate determining. General agreement was found with natural precipitates. The overall adsorption behaviour of aged Fe (II) and Fe (III) precipitates suggested a physical process and an electrostatic adsorption model was proposed. Aged Fe (II) material did not adsorb As (III) and an Fe (III) - As (III) redox model was developed to account for the general slowness of As (III) adsorption. Natural aged precipitates showed complex adsorption behaviour, confirmed by precipitate characterisation studies which indicated a mixed oxide composition. The estuarine behaviour of As was interpreted in terms of the adsorption models and estuarine surveys. A model illustrating the timescales of As adsorption and desorption within an estuary was developed, and used to elucidate the anomalous behaviour of dissolved Fe, Mn and As in the River Carnon, Cornwall.Marine Biological Association, The Laboratory, The Hoe, Plymouth, Devo

A mineral reconnaissance survey of the Abington-Biggar-Moffat-area, south-central Scotland

Panned heavy mineral concentrates, mostly obtained from stream sediments, were collected from 195 sites in the Abington-Biggar-Moffat area. The project area, which lies immediately east of the formerly important mining district of Wanlockhead-Leadhills, covers approximately 500 km2 of the north-central sector of the Southern Uplands. It incorporates the Hart Fell range of hills, the headwaters catchment for the River Tweed and River Annan, some tributaries of the River Clyde, and, to the east, the Culter Water, Talla Reservoir, Megget Water and the head of the Ettrick valley. Numerous new occurrences of lead, zinc, copper and barium minerals were found and nine areas are recommended for further investigation. Minor amounts of baryte and traces of cupriferous pyrite were identified in the basal breccia of the-New Red Sandstone deposits in Annandale. The mercury mineral, cinnabar, was identified for the first time in Scotland, occurring in trace amounts in stream sediment concentrates in the Coulter area close to the Southern Upland Fault. Chromiferous spine1 was recognised as a major constituent in the majority of panned samples. It is present as a detrital mineral in greywackes but must have been originally derived from ultrabasic rocks. An unusual mineral widely dispersed in trace amounts is corundum (including some gem-quality sapphire). Historical references (Lauder Lindsay, 1868-9, 1871) to a wide distribution for particle gold were confirmed and many new occurrences found. A local provenance for the element is now considered certain. Some placer concentration of gold and chromiferous spine1 is likely in the alluvium of the valleys of the River Tweed and the Megget Water. Six greywacke formations, previously defined in other parts of the Southern Uplands, were mapped in the project area, each distinguished by a characteristic lithology and heavy mineral content