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At least 451 records · Page 25Linked to original sources
USGS1998

Lithology and fracture characterization from drilling investigations in the Mirror Lake area, Grafton County, New Hampshire

The lithology and fracture network of the bedrock aquifer in the Mirror Lake area were characterized from hydrogeologic data collected from 1979-95 in Grafton County, N.H. The collection of these data is an integral part of an ongoing multidisciplinary study by the U.S. Geological Survey to characterize groundwater flow and solute transport in fractured rock. The data provide a physical framework and enable the characterization of the fractures and the rock types in the bedrock aquifer in the Mirror Lake study area. In addition, these data provide a detailed description of the subsurface intersected by boreholes that can be used to compare the results of other borehole testing. The Mirror Lake area is characterized by steep bedrock uplands that are mostly covered by colluvium, discontinuous stratified-drift deposits, and glacial till that varies locally in thickness from less than 10 meters to as much as 50 meters. The land-surface altitude ranges from 180 meters near the Pemigewasset River to 720 meters on the mountain top on the northwestern side of the study area. The bedrock in the area is predominantly sillimanite-grade pelitic schists that have been complexly folded and intruded by granitoids, pegmatites, and diabase dikes. The bedrock has been fractured in response to local and tectonic stress. The resulting interconnected network of fractures forms the bedrock aquifer. This report describes the lithologic units in the study area and provides a characterization of the lithology and fractures found in 40 boreholes, which range in depth from 60 to 305 meters, that were drilled for this study. Drilling logs and color video surveys were used to locate and characterize the fractures and rock types in the subsurface. Solid bedrock core was obtained from three of the boreholes. Petrographic thin-section, x-ray diffraction and scanning electron microscope with energy dispersive x-ray fluorescence spectrometry analyses were done on selected samples from boreholes and outcrops. Observations recorded at the time of drilling, descriptions of rock samples collected from the boreholes, interpretation of rock type and fractures based on boreholeimaging surveys, descriptions of rock core and petrographic analyses of selected rock samples are in tables and figures. Analysis of the data provided information on the distribution of fractures and lithology in the boreholes at Mirror Lake. The relative abundances of the rock types were computed for three groups of boreholes, including (1) the Forest Service Experimental (FSE) well field, (2) the Camp Osceola (CO) well field, and (3) the index boreholes, which are 15 boreholes distributed areally throughout the study area including the deepest borehole from each of the two well fields. The index boreholes are separated by hundreds of meters and are typically 100 meters deep. The FSE well field includes 13 boreholes that are separated by 10 to 40 meters. These 13 boreholes are approximately 100 meters deep, except for one borehole that is 230 meters deep. The rocks penetrated by the FSE wells are predominantly igneous. Approximately 70 percent of the rocks encountered in the boreholes in the FSE well field were granite, pegmatite, and aplite. The CO well field includes 9 boreholes that range from 60-70 meters deep and one borehole that is 175 meters deep. The rocks encountered in these boreholes were predominantly metamorphic. The distribution of rock types in the CO well field is similar to the distribution of rocks in highway roadcuts, that are approximately 90 to 150 meters east of the well field. Seventy percent of the roadcut exposures are schist. Collectively, in the 15 index boreholes, the metamorphic and igneous rocks are equally distributed. Analysis of the rock types in these boreholes indicates that the rock types tend to "change" every 5 to 9 meters. Although the metamorphic and igneous rocks each comprise approximately 50 percent of the rock types observed in the 15 index boreholes, 73 percent of the fractures were in the igneous rocks. This indicates that the granitoids tend to be more fractured than the metamorphic rocks. Pegmatite, diabase, quartzite, and gneissic rocks are relatively unfractured. Boreholes completed in bedrock generally have one or two water-bearing zones, which were identified during the drilling process. At the completion of drilling a borehole, the driller estimated the yield of the borehole with an air-lift test. Yields estimated by drillers ranged from less than 3 to 378 liters per minute. These yields are typical of the yields measured for domestic wells in Grafton County. Water levels measured in the open boreholes after the boreholes recovered from the hydraulic stresses of drilling were usually in the steel casing and were within 10 meters of the land surface. Water levels in eight of the boreholes were above the top of casing or above land surface.

New Hampshire↗
USGS1970

Study and interpretation of the chemical characteristics of natural water

The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from activities of man. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural fresh water. The ways in which solutes are taken up or precipitated and the amounts present in solution are influenced by many environmental factors, especially climate, structure and position: of rock strata, and biochemical effects associated with life cycles of plants and animals, both microscopic and macroscopic. Taken all together and in application with the further influence of the general circulation of all water in the hydrologic cycle, the chemical principles and environmental factors form a basis for the developing science of natural-water chemistry. Fundamental data used in the determination of water quality are obtained by the chemical analysis of water samples in the laboratory or onsite sensing of chemical properties in the field. Sampling is complicated by changes in composition of moving water and the effects of particulate suspended material. Most of the constituents determined are reported in gravimetric units, usually milligrams per liter or milliequivalents per liter. More than 60 constituents and properties are included in water analyses frequently enough to provide a basis for consideration of the sources from which each is generally derived, most probable forms of elements and ions in solution, solubility controls, expected concentration ranges and other chemical factors. Concentrations of elements that are commonly present in amounts less than a few tens of micrograms per liter cannot always be easily explained, but present information suggests many are controlled by solubility of hydroxide or carbonate or by sorption on solid particles. Chemical analyses may be grouped and statistically evaluated by averages, frequency distributions, or ion correlations to summarize large volumes of data. Graphing of analyses or of groups of analyses aids in showing chemical relationships among waters, probable sources of solutes, areal water-quality regimen, and water-resources evaluation. Graphs may show water type based on chemical composition, relationships among ions, or groups of ions in individual waters or many waters considered simultaneously. The relationships of water quality to hydrologic parameters, such as stream discharge rate or ground-water flow patterns, can be shown by mathematical equations, graphs, and maps. About 75 water analyses selected from the literature are tabulated to illustrate the relationships described, and some of these, along with many others that are not tabulated, are also utilized in demonstrating graphing and mapping techniques. Relationships of water composition to source rock type are illustrated by graphs of some of the tabulated analyses. Activities of man may modify water composition extensively through direct effects of pollution and indirect results of water development, such as intrusion of sea water in ground-water aquifiers. Water-quality standards for domestic, agricultural, and industrial use have been published by various agencies. Irrigation project requirements for water quality are particularly intricate. Fundamental knowledge of processes that control natural water composition is required for rational management of water quality.

Water Supply Paper↗
USGS1959

Study and interpretation of the chemical characteristics of natural water

The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from activities of man. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural fresh water. The ways in which solutes are taken up or precipitated and the amounts present in solution are influenced by many environmental factors, especially climate, structure and position: of rock strata, and biochemical effects associated with life cycles of plants and animals, both microscopic and macroscopic. Taken all together and in application with the further influence of the general circulation of all water in the hydrologic cycle, the chemical principles and environmental factors form a basis for the developing science of natural-water chemistry. Fundamental data used in the determination of water quality are obtained by the chemical analysis of water samples in the laboratory or onsite sensing of chemical properties in the field. Sampling is complicated by changes in composition of moving water and the effects of particulate suspended material. Most of the constituents determined are reported in gravimetric units, usually milligrams per liter or milliequivalents per liter. More than 60 constituents and properties are included in water analyses frequently enough to provide a basis for consideration of the sources from which each is generally derived, most probable forms of elements and ions in solution, solubility controls, expected concentration ranges and other chemical factors. Concentrations of elements that are commonly present in amounts less than a few tens of micrograms per liter cannot always be easily explained, but present information suggests many are controlled by solubility of hydroxide or carbonate or by sorption on solid particles. Chemical analyses may be grouped and statistically evaluated by averages, frequency distributions, or ion correlations to summarize large volumes of data. Graphing of analyses or of groups of analyses aids in showing chemical relationships among waters, probable sources of solutes, areal water-quality regimen, and water-resources evaluation. Graphs may show water type based on chemical composition, relationships among ions, or groups of ions in individual waters or many waters considered simultaneously. The relationships of water quality to hydrologic parameters, such as stream discharge rate or ground-water flow patterns, can be shown by mathematical equations, graphs, and maps. About 75 water analyses selected from the literature are tabulated to illustrate the relationships described, and some of these, along with many others that are not tabulated, are also utilized in demonstrating graphing and mapping techniques. Relationships of water composition to source rock type are illustrated by graphs of some of the tabulated analyses. Activities of man may modify water composition extensively through direct effects of pollution and indirect results of water development, such as intrusion of sea water in ground-water aquifiers. Water-quality standards for domestic, agricultural, and industrial use have been published by various agencies. Irrigation project requirements for water quality are particularly intricate. Fundamental knowledge of processes that control natural water composition is required for rational management of water quality.

Water Supply Paper↗
USGS1967

Form and stability of aluminum hydroxide complexes in dilute solution

Laboratory studies of solutions 4.53 x 10 -4 to 4.5 x 10 -5 molal (12.2-1.2 ppm) in aluminum, in 0.01 molal sodium perchlorate, were conducted to obtain information as to the probable behavior of aluminum in natural water. When the solutions were brought to pH 7.5-9.5 and allowed to stand for 24 hours, a precipitate was obtained which was virtually amorphous as shown by X-rays, and which had a solubility equivalent to that of boehmite. This precipitate had a hydrolysis constant (*Ks4) of 1.93 x 10 -13a. When solutions were allowed to stead at this pH range for 10 days, their precipitates gave the X-ray pattern of bayerite (*Ks4 = 1.11 > (10- 4). These hydrolysis constants were obtained at 25?C. and corrected to zero ionic strength and are in close agreement with other published values. The predominant dissolved form in this pH range is Al(OH) -4. Below neutral pH (7.0) the dissolved aluminum species consist of octahedral units in which each aluminum ion is surrounded by six water molecules or hydroxide ions. Single units such as Al(OH2)6 + 3 and AlOH(OH2)5+2 are most abundant below pH 5.0, and where the molar ratio (r) of combined hydroxide to total dissolved aluminum is low. When r is greater than 1.0, polymerization of the octahedral units occurs. When r is between 2.0 and 3.0, solutions aged for 10 days or more contained colloidal particles between 0.10 and 0.45 ? in diameter. Particles whose diameters were greater than 0.10 ? were identified by X-ray diffraction as gibbsite. Particles smaller than 0.10 ? were also present and were shown by means of the electron microscope to have a hexagonal crystal pattern. Structured material consisting of sheets of coalesced six-membered rings of aluminum ions held together by double OH bridges has a distinctive kinetic behavior. This property was used to determine amounts of polymerized material in solutions having r between 1.0 and 3.0 after aging times ranging from a few hours to more than 4 months. Aging increased the size and orderliness of the polymeric aggregates and was accompanied by a decrease in the pH of the solution. The kinetic experiments and stoichiometric data for solutions aged for long periods provided a means of determining activities of polymerized aluminum. From these values the solubility product for microcrystalline gibbsite was determined to be 2.24 x 10 -3, and its free energy of formation, -? 272.3 0.4 kcal per mole. Where polymerization was observed, the process did not stop with small polynuclear complexes containing a few aluminum ions, but proceeded with aging until macromolecules or colloidal-sized particles were formed.

Water Supply Paper↗
USGS1985

Study and interpretation of the chemical characteristics of natural water

The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater. The ways in which solutes are taken up or precipitated and the amounts present in solution are influenced by many environmental factors, especially climate, structure and position of rock strata, and biochemical effects associated with life cycles of plants and animals, both microscopic and macroscopic. Taken together and in application with the further influence of the general circulation of all water in the hydrologic cycle, the chemical principles and environmental factors form a basis for the developing science of natural-water chemistry. Fundamental data used in the determination of water quality are obtained by the chemical analysis of water samples in the laboratory or onsite sensing of chemical properties in the field. Sampling is complicated by changes in the composition of moving water and by the effects of particulate suspended material. Some constituents are unstable and require onsite determination or sample preservation. Most of the constituents determined are reported in gravimetric units, usually milligrams per liter or milliequivalents per liter. More than 60 constituents and properties are included in water analyses frequently enough to provide a basis for consideration of the sources from which each is generally derived, the most probable forms of elements and ions in solution, solubilitycontrols, expected concentration ranges, and other chemical factors. Mechanisms that control concentrations of elements commonly present in amounts less than a few tens of micrograms per liter cannot always be easily ascertained, but present information suggests that many are controlled by solubility of their hydroxides or carbonates or by sorption on solid particles. Many dissolved organic compounds can now be specifically determined. Chemical analyses may be grouped and statistically evaluated by means, medians, frequency distributions, or ion correlations to summarize large volumes of data. Graphing of analyses or of groups of analyses aids in showing chemical relationships among water, probable sources of solutes, areal water-quality regimen, temporal and spatial variation, and water-resources evaluation. Graphs may show water type based on chemical composition, relationships among ions, or groups of ions in individual waters or many waters considered simultaneously. The relationships of water quality to hydrogeologic characteristics, such as stream discharge rate or ground-water flow patterns, can be shown by mathematical equations, graphs, and maps. About 80 water analyses selected from the literature are tabulated to illustrate the relationships described, and some of these, along with many others that are not tabulated, are also used in demonstrating graphing and mapping techniques. Relationships of water composition to source rock type are illustrated by graphs of some of the tabulated analyses. Human activities may modify water composition extensively through direct effects of pollution and indirect results of water development, such as intrusion of seawater in groundwater aquifers. Water-quality standards for domestic, agricultural, and industrial use have been published by various agencies. Irrigation project requirements for water quality are particularly intricate. Fundamental knowledge of processes that control natural-water composition is required for rational management of water quality.

Water Supply Paper↗
USGS2002

Feeding habits of the endangered Ozark big-eared bat (Corynorhinus townsendii ingens) relative to prey abundance

Feeding habits of the endangered Ozark big-cared bat (Corynorhinus townsendii ingens) in eastern Oklahoma, USA, were studied from July 1987 through July 1988. Diets were determined from microscopic analysis of fecal pellets and compared with arthropods collected in Malaise traps. Although lepidopterans comprised only 21.5% of the available prey, they occurred in > 90% of the pellets examined and accounted for > 85% of the volume of prey consumed. Dipterans, coleopterans, and homopterans occurred in 18.3%, 10,6%, and 6.7% of the feces, respectively, but each accounted for < 5% of the volume of prey consumed. Trichopterans, hymenopterans, and neuropterans also were found in feces but in trace amounts. Our results support the classification of C. t. ingens as a moth specialist, but additional insights are needed to fully understand how its feeding tactics conform to the allotonic frequency hypothesis (i.e., avoiding detection by cared moths). Conservation of this highly endangered North American bat will require, in part, maintenance of habitats capable of supporting abundant populations of Lepidoptera.

Acta Chiropterologica↗
USGS2010

White-nose syndrome fungus (Geomyces destructans) in bats, Europe

White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus ( Geomyces destructans ) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

Emerging Infectious Diseases↗
USGS2012

Disseminated toxoplasmosis in Antillean manatees Trichechus manatus manatus from Puerto Rico

Necropsies were conducted on 4 Antillean manatees Trichechus manatus manatus that were stranded in single events on the coastal beaches of Puerto Rico from August 2010 to August 2011. Three manatees were emaciated and the gastrointestinal tracts were devoid of digesta. Microscopically, all manatees had severe widespread inflammatory lesions of the gastrointestinal tract and heart with intralesional tachyzoites consistent with Toxoplasma gondii identified by histological, ultrastructural and immunohistochemical techniques. The gastrointestinal lesions included severe, multifocal to diffuse, chronic-active enteritis, colitis and/or gastritis often with associated ulceration, necrosis and hemorrhage. Enteric leiomyositis was severe and locally extensive in all cases and associated with the most frequently observed intralesional protozoans. Moderate to severe, multifocal, chronic to chronic-active, necrotizing myocarditis was also present in all cases. Additionally, less consistent inflammatory lesions occurred in the liver, lung and a mesenteric lymph node and were associated with fewer tachyzoites. Sera (n = 30) collected from free-ranging and captive Puerto Rican manatees and a rehabilitated/released Puerto Rican manatee from 2003 to 2012 were tested for antibodies for T. gondii . A positive T. gondii antibody titer was found in 2004 in 1 (3%) of the free-ranging cases tested. Disease caused by T. gondii is rare in manatees. This is the first report of toxoplasmosis in Antillean manatees from Puerto Rico. Additionally, these are the first reported cases of disseminated toxoplasmosis in any sirenian. The documentation of 4 cases of toxoplasmosis within one year and the extremely low seroprevalence to T. gondii suggest that toxoplasmosis may be an emerging disease in Antillean manatees from Puerto Rico.

Diseases of Aquatic Organisms↗
USGS2020

Hyperpigmented melanistic skin lesions of smallmouth bass Micropterus dolomieu from the Chesapeake Bay watershed

Hyperpigmented melanistic skin lesions (HPMLs) of smallmouth bass Micropterus dolomieu are observed in the Potomac and Susquehanna rivers, Chesapeake Bay watershed, USA. Routine, nonlethal population surveys were conducted at 8 sites on the mainstem Susquehanna River and 9 on the Juniata River, a tributary of the Susquehanna River, between 2012 and 2018, and the prevalence of HPMLs was documented. A total of 4078 smallmouth bass were collected from the mainstem Susquehanna River and 6478 from the Juniata River. Lesions were primarily seen in bass greater than 200 mm, and prevalence in the Susquehanna River (8%) was higher (p < 0.001) than in the Juniata River (2%). As part of ongoing fish health monitoring projects, smallmouth bass were collected at additional sites, primarily tributaries of the Susquehanna (n = 758) and Potomac (n = 545) rivers between 2013 and 2018. Prevalence in the Susquehanna River (13%) was higher (p < 0.001) than the Potomac (3%). Microscopically, HPMLs were characterized by an increased number of melanocytes in the epidermis or within the dermis and epidermis. RNAseq analyses of normal and melanistic skin identified 3 unique sequences in HPMLs. Two were unidentified and the third was a viral helicase (E1). Transcript abundance in 16 normal skin samples and 16 HPMLs showed upregulation of genes associated with melanogenesis and cell proliferation in HPMLs. The E1 transcript was detected in 12 of the 16 melanistic areas but in no samples from normal skin. Further research will be necessary to identify the putative new virus and determine its role in melanocyte proliferation.

Delaware, Maryland, Pennsylvania, Virginia, West V↗
USGS2020

Cytology reveals diverse cell morphotypes and cellin-cell interactions in normal collector sea urchins Tripneustes gratilla

Echinoderms such as sea urchins are important in marine ecosystems, particularly as grazers, and unhealthy sea urchins can have important ecological implications. For instance, unexplained mortalities of Diadema antillarum in the Caribbean were followed by algal overgrowth and subsequent collapse of coral reef ecosystems. Unfortunately, few tools exist to evaluate echinoderm health, making management of mortalities or other health issues problematic. Hematology is often used to assess health in many animal groups, including invertebrates, but is seldom applied to echinoderms. We used a standard gravitometric technique to concentrate fixed coelomocytes from the collector sea urchin Tripneustes gratilla onto microscope slides, permitting staining and enumeration. Using Romanowsky stain and electron microscopy to visualize cell details, we found that urchin cells could be partitioned into different morphotypes. Specifically, we enumerated phagocytes, phagocytes with perinuclear cytoplasmic dots, vibratile cells, colorless spherule cells, red spherule cells, and red spherule cells with pink granules. We also saw cell-in-cell interactions characterized by phagocytes apparently phagocytizing mainly the motile cells including red spherule cells, colorless spherule cells, and vibratile cells disproportionate to underlying populations of circulating cells. Cell-in-cell interactions were seen in 71% of sea urchins, but comprised <1% of circulating cells. Finally, about 40% of sea urchins had circulating phagocytes that were apparently phagocytizing spicules. The coelomic fluid collection and slide preparation methods described here are simple, field portable, and might be a useful complementary tool for assessing health of other marine invertebrates, revealing heretofore unknown physiological phenomena in this animal group.

Hawaii↗
USGS2023

Mass mortality of collector urchins Tripneustes gratilla in Hawai`i

As grazers, sea urchins are keystone species in tropical marine ecosystems, and their loss can have important ecological ramifications. Die-offs of urchins are frequently described, but their causes are often unclear, in part because systematic examinations of animal tissues at gross and microscopic level are not done. In some areas, urchins are being employed to control invasive marine algae. Here, we describe the pathology of a mortality event in Tripneustes gratilla in Hawai`i where urchins were translocated to control invasive algae. Although we did not determine the cause of the mortality event, our investigation indicates that animals died from inflammation of the test and epidermal ulceration, followed by inability to maintain coelomic fluid volume, colonization of coelomic fluid by opportunists (diatom, algae), and inappetence. Parasites, bacteria, fungi, and viruses were not evident as a primary cause of death. Pathology was suggestive of a toxin or other environmental cause such as lack of food, possibilities that could be pursued in future investigations. These findings highlight the need for caution and additional tools to better assess health when translocating marine invertebrates to ensure maximal biosecurity.

Hawaii↗
USGS2018

Conserving all the pollinators: Variation in probability of pollen transport among insect taxa

As concern about declining pollinator populations mounts, it is important to understand the range of insect taxa that provide pollination services. We use pollen transport information acquired over three years in two habitats at Badlands National Park, South Dakota, USA, to compare probabilities of pollen transport among insect taxa and between sexes of bees. Sampling was conducted on 1-ha plots, eight in sparse vegetation (May–October samples; N = 74 surveys) and 12 in wheatgrass prairie vegetation (June–July samples; N = 87 surveys). Insects contacting reproductive parts of flowers were netted, placed individually into tubes charged with ethyl acetate, then transferred to individual labeled glassine envelopes for transport to the lab. Pollen was removed from insect bodies with fuchsin jelly cubes which were then mounted on microscope slides for identification. The probability of taxa transporting only conspecific pollen (with respect to the plant species upon which it was collected), mixed pollen, only non-conspecific, or no pollen was estimated with multinomial logistic regression. Bees were the most commonly captured flower visitor and carried by far the most pollen (females >10× as much as males), but they were most likely to carry mixed pollen loads. Flies, beetles, and wasps were also common flower visitors and beetles were most likely to carry only conspecific pollen. Ants and diurnal lepidopterans were unlikely to carry any pollen. Bees, beetles, flies, and wasps varied in the timing and habitat in which they were most likely to transport pollen, suggesting that all played a role in providing robust pollination services.

South Dakota↗
USGS2019

Soil aggregates as a source of dissolved organic carbon to streams: An experimental study on the effect of solution chemistry on water extractable carbon

Over the past two decades, headwater streams of the northern hemisphere have shown increased amounts of dissolved organic carbon (DOC), coinciding with decreased acid deposition. The exact nature of the mechanistic link between precipitation composition and stream water DOC is still widely debated in the literature. We hypothesize that soil aggregates are the main source of stream water DOC and that DOC release is greater in organic rich, riparian soils vs. hillslope soils. To test these hypotheses, we collected soils from two main landscape positions (hillslope and riparian zones) from the acid-impacted Sleepers River Research Watershed in northeastern Vermont. We performed aqueous soil extracts with solutions of different ionic strength (IS) and composition to simulate changes in soil solution. We monitored dynamic changes in soil particle size, aggregate architecture and composition, leachate DOC concentrations, dissolved organic matter (DOM) characteristics by fluorescence spectroscopy and trends in bioavailability. In low IS solutions, extractable DOC concentrations were significantly higher, particle size (by laser diffraction) was significantly smaller and organic material was separated from mineral particles in scanning electron microscope observations. Furthermore, higher DOC concentrations were found in Na + compared to Ca 2+ solutions of the same IS. These effects are attributed to aggregate dispersion due to expanding diffuse double layers in decreased IS solutions and to decreased bridging by divalent cations. Landscape position impacted quality but not quantity of released DOC. Overall, these results indicate that soil aggregates might be one important link between Critical Zone inputs (i.e., precipitation) and exports in streams.

Vermont↗
USGS2020

Emergence of a zoonotic pathogen in a coastal marine sentinel: Capillaria hepatica (syn. Calodium hepaticum)-associated hepatitis in southern sea otters (Enhydra lutris nereis)

Capillaria hepatica is a globally distributed zoonotic nematode parasite that most commonly infects feral and native rats. Soil contact, pica, and living in close proximity to rat populations are risk factors for human infection. Larval nematodes and eggs that were morphologically consistent with C. hepatica were observed microscopically in livers of stranded southern sea otters ( Enhydra lutris nereis ) from California. Large (90–100 × 45–55 μm), barrel-shaped non-embryonated parasite eggs with large polar prominences and a roughened or striated surface, or 105–120 μm diameter larval aphasmid nematode profiles with a prominent stichosome and hypodermal bands were observed in the livers of three otters. The liver of a fourth animal exhibited serpiginous tracts of necrosis, micro-cavitation and pleocellular inflammation, with intralesional linear eosinophilic material that resembled cuticle from degenerating metazoan parasites. Capillaria hepatica -associated hepatitis and capsular adhesions were the cause of death for one otter, and parasite-associated liver lesions were observed in all cases. All infected otters were adult females that stranded from 2006 through 2016 at multiple sites along the central California coast. All cases stranded from December through May; during and soon after peak seasonal precipitation and land-sea runoff in California. This same seasonal pattern has been reported for other land-based parasites infecting southern sea otters. Neither C. hepatica , nor any similar nematodes have been reported from marine mammals, and southern sea otters are not typical hosts for C. hepatica or any other nematode parasites. The most likely route of exposure was via freshwater runoff containing embryonated eggs liberated from predated or decomposing terrestrial hosts, especially rats. Similar to the land-based parasites Toxoplasma gondii and Sarcocystis neurona , C. hepatica eggs may be concentrated and transmitted through filter-feeding marine invertebrates that serve as southern sea otter prey, which may also pose an unrecognized public health risk for people who consume these species.

California↗
USGS2020

Stony coral tissue loss disease in Florida is associated with disruption of host–zooxanthellae physiology

Samples from eight species of corals ( Colpophyllia natans , Dendrogyra cylindrus , Diploria labyrinthiformis , Meandrina meandrites , Montastraea cavernosa , Orbicella faveolata, Pseudodiploria strigosa , and Siderastrea siderea ) that exhibited gross clinical signs of acute, subacute, or chronic tissue loss attributed to stony coral tissue loss disease (SCTLD) were collected from the Florida Reef Tract during 2016–2018 and examined histopathologically. The hallmark microscopic lesion seen in all eight species was focal to multifocal lytic necrosis (LN) originating in the gastrodermis of the basal body wall (BBW) and extending to the calicodermis, with more advanced lesions involving the surface body wall. This was accompanied by other degenerative changes in host cells such as mucocyte hypertrophy, degradation and fragmentation of gastrodermal architecture, and disintegration of the mesoglea. Zooxanthellae manifested various changes including necrosis (cytoplasmic hypereosinophilia, pyknosis); peripheral nuclear chromatin condensation; cytoplasmic vacuolation accompanied by deformation, swelling, or atrophy; swollen accumulation bodies; prominent pyrenoids; and degraded chloroplasts. Polyhedral intracytoplasmic eosinophilic periodic acid–Schiff-positive crystalline inclusion bodies (∼1–10 μm in length) were seen only in M. cavernosa and P. strigosa BBW gastrodermis in or adjacent to active lesions and some unaffected areas (without surface lesions) of diseased colonies. Coccoidlike or coccobacilloidlike structures (Gram-neutral) reminiscent of microorganisms were occasionally associated with LN lesions or seen in apparently healthy tissue of diseased colonies along with various parasites and other bacteria all considered likely secondary colonizers. Of the 82 samples showing gross lesions of SCTLD, 71 (87%) were confirmed histologically to have LN. Collectively, pathology indicates that SCTLD is the result of a disruption of host–symbiont physiology with lesions originating in the BBW leading to detachment and sloughing of tissues from the skeleton. Future investigations could focus on identifying the cause and pathogenesis of this process.

Florida↗
USGS2025

Testicular neoplasms and other abnormalities in common carp Cyprinus carpio from the Lower Colorado River, United States

Abnormalities were observed in the testes of common carp Cyprinus carpio collected from Willow Beach, Arizona, USA, a site on the lower Colorado River, downstream of Lake Mead and Hoover Dam. Testicular tissue collected from this site in 2003 exhibited numerous large, pigmented macrophage aggregates (MAs) and a novel, previously undescribed hypertrophy and proliferation of putative Sertoli cells. In testes samples collected in 2007, numerous testicular MA, testicular oocytes, and proliferations of Sertoli cells were observed. Three carp collected in 2007 also had raised nodules within the testes, and, microscopically, seminoma, spermatogenic seminoma, and mixed stromal cell–germ cell neoplasms were diagnosed. Several risk factors for these adverse effects were identified. Carp collected at this site in 2003 ranged in age from 35 to 54 years and had the oldest mean age of the thirteen sites sampled within the Colorado River basin. This site also has an unusual thermal regime when compared to other sites studied in Lake Mead and upstream sites, in that temperatures varied little over the seasons (amplitude around 1.5 °C) and barely reached 15 °C. Additionally, carp from this site had the highest total polychlorinated biphenyl (PCB) body burden. Hence, advanced age, low water temperature, and exposure to PCBs and other environmental contaminants may contribute to the observed abnormalities, highlighting the complex environmental factors initiating pre-neoplastic and neoplastic changes in wild carp.

Arizona↗
USGS2018

Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium , Pythium and other water moulds cause seed rots during germination. Fusarium blights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass ( Cynodon dactylon ), or annual bluegrass ( Poa annua ) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum . We found that three bacteria belonging to genus Pseudomonas spp. (SLB4- P. fluorescens , SLB6- Pseudomonas sp. and SY1- Pseudomonas sp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum , 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production suggested presence of genes for both compounds in the genome of SY1. HCN was detected in cultures of SY1. We conclude that microbes from non-cultivated plants may provide disease protection and promote growth of crop plants.

Microorganisms↗
USGS2025

Cell penetrating peptide-mediated delivery of gene-silencing nucleic acids to the invasive common reed Phragmites australis via foliar application

As a popular tool for gene function characterization and gene therapy, RNA interference (RNAi)-based gene silencing has been increasingly explored for potential applications to control invasive species. At least two major hurdles exist when applying this approach to invasive plants: (1) the design and screening of species- and gene-specific biomacromolecules (i.e., gene-silencing agents or GSAs) made of DNA, RNA, or peptides that can suppress the expression of target genes efficiently, and (2) the delivery vehicle needed to penetrate plant cell walls and other physical barriers (e.g., leaf cuticles). In this study, we investigated the cell-penetrating peptide (CPP)-mediated delivery of multiple types of GSAs (e.g., double-stranded RNA (dsRNA), artificial microRNA (amiRNA), and antisense oligonucleotide (ASO)) to knock down a putative phytoene desaturase ( PDS ) gene in the invasive common reed ( Phragmites australis spp. australis ). Both microscopic and quantitative gene expression evidence demonstrated the CPP-mediated internalization of GSA cargos and transient suppression of PDS expression in both treated and systemic leaves up to 7 days post foliar application. Although various GSA combinations and application rates and frequencies were tested, we observed limitations, including low gene-silencing efficiency and a lack of physiological trait alteration, likely owing to low CPP payload capacity and the incomplete characterization of the PDS-coding genes (e.g., the recent discovery of two PDS paralogs) in P. australis . Our work lays a foundation to support further research toward the development of convenient, cost-effective, field-deployable, and environmentally benign gene-silencing technologies for invasive P. australis management.

Mississippi, Ohio↗