bluuebunny/crossref_metadata_2025 huggingface dataset:
THE DISTRIBUTION OF ORGANIC PHOSPHORUS IN BRITISH COLUMBIA SOILS AND ITS RELATIONSHIP TO SOIL CHARACTERISTICS
Authors: John M. K. , Sprout P. N. , Kelley C. C.
Published: March 2010

The relationship of organic phosphorus content to a number of chemical properties was studied in the surface horizons of 38 soils of six different soil orders in British Columbia.The concentration of organic P ranged from 1.8 to 77.7% of the total P with amounts varying from 21 to 802 p.p.m. The forested soils of the Podzolic and Brunisolic Orders contained the least organic P. However, the wide range in organic P content within some soil orders indicated that its distribution was not entirely characteristic of the soil order.Simple correlation studies between organic P and nitrogen, carbon, pH, per cent base saturation, total P, and free iron in all soils before assigning them to groups indicated that only nitrogen and carbon were significantly related to organic P. Significant relationships between the other variables and organic P were restricted to specific soil orders. The organic P content has been found to be primarily dependent on nitrogen and pH, since the inclusion of the other independent variables in the multiple regression did not significantly change the coefficient of determination.The range of C/organic P and N/organic P ratios for the 38 samples was between 46 and 648 and 5.5 to 57.6 respectively. Soil pH was the only variable studied which could account for the wide variation of these ratios.
A NEW SOIL-EXTRACTING APPARATUS
Authors: Gillingham J. T.
Published: March 2010

not available
A CORE SAMPLER FOR ORGANIC DEPOSITS
Authors: Holowaychuk N. , Wilding L. P. , Gersper P. L.
Published: March 2010

not available
DETERMINATION OF EVAPOTRANSPIRATION USING THE NEUTRON SCATTERING METHOD
Authors: Bowman D. H. , King K. M.
Published: March 2010

The accuracy of evapotranspiration (E.T.) determinations by the neutron scattering method was found by studying each of the possible errors. For the gravelly soils studied the probable error in E.T. was less than 0.15 in. of water for a weekly period and less than 0.62 in. for a 3-month period when one sampling site was used. Increasing the number of sampling sites decreased the error but not in direct proportion. The method was used to provide values for evapotranspiration from irrigated and unirrigated corn, wheat, and clover.
CLAY ILLUVIATION IN SOME ORTHIC PODZOLS OF EASTERN CANADA
Authors: Brydon J. E.
Published: March 2010

The Arago, Barney, and Holmesville soils, Podzols from Quebec, Nova Scotia, and New Brunswick, respectively, each had friable Bfh horizons with moderate granular structure, and with organic matter and free Fe2O3 contents greater than the Ae and C horizons. The Arago and Holmesville had thin Bhft horizons containing over 10% organic matter and 5% free iron oxides. The C horizons of these two soils had some features characteristic of fragipans.The B horizons of the three soils had a high "pH-dependent charge component" in the C.E.C. values. The "permanent charge component" was similar throughout the Arago profile except for the Bhft horizon where clay accumulation had occurred.Translocation of clay from the Ae to the upper B horizons was indicated by the twofold increase in clay content and the relative enrichment of fine clay in the B horizons. Removal of free iron affected the clay contents differently in the different: horizons but the maximum clay content in the upper B horizons remained. The definitions of Orthic Podzols, Textural Podzols, and t horizons should be re-examined.
INFLUENCE OF SALTS IN ASSOCIATION WITH MONOCALCIUM AND DIAMMONIUM PHOSPHATES ON THE CHEMICAL CHARACTERISTICS AND MOVEMENT OF SOIL SOLUTION
Authors: Hamilton Herman A. , Lathwell D. J.
Published: March 2010

Various salts thoroughly mixed with monocalcium phosphate monohydrate (MCP) and diammonium phosphate (DP) were made to react with moist Lima silt loam soil arranged in 5-mm layers and separated by filter papers. After a reaction period of 3 weeks, soil moisture, pH, hot nitric acid-soluble phosphorus, and sodium bicarbonate-soluble phosphorus were determined in the different layers. As compared with MCP, the more soluble salts in association with MCP enhanced soil solution movement away from the fertilizer layer, and there was considerably greater movement of soil solution from the fertilizer layer with DP compared with MCP. The movement of soil solution with DP was attendant with greater movement of phosphorus into soil layers than for MCP, with the result that phosphorus was distributed into a greater volume of soil. When calcium sulphate was associated with DP, movement of soil solution and the diffusion of phosphorus into soil layers was markedly restricted because of massive precipitation reactions. At the soil layer closest to the MCP–fertilizer layer, a pH of 2.8 units developed. These very acid conditions were in every case ameliorated when MCP was associated with different soils. No changes in the natural soil pH were occasioned by the use of DP.By sampling soil solutions with filter papers at increasing distances from a fertilizer layer containing MCP, considerable amounts of Al, Fe, Mn, and Ca were detected. When various salts were associated with MCP, the amounts of soluble constituents moved to greater distances than with pure MCP, thereby effecting a greater diffusion of potentially toxic elements into a greater volume of soil. Chloride salts were particularly effective in causing the diffusion of manganese away from the fertilizer layer. No measurable amounts of Al, Fe, or Mn were found in soil solutions when DP reacted in soil.
EXTRACTION OF ORGANIC PHOSPHORUS FROM SOILS WITH SODIUM BICARBONATE
Authors: MacLean A. A.
Published: March 2010

Sodium bicarbonate extractable organic phosphorus increased with increasing pH of extractant, temperature, time of extraction, and soil/solution ratio. The inclusion of an acid pretreatment resulted in higher organic phosphorus levels than bicarbonate extraction only.The proposed method involves extraction with 0.5 M sodium bicarbonate at pH 10.0 for 16 hours at 90 °C following acid pretreatment with 0.5 N hydrochloric acid for 1 hour. Under these conditions 98.8% of the total organic phosphorus, as estimated by the method of Mehta et al., was extracted.
EXCHANGE EQUILIBRIA FOR Al–BENTONITE AND MONOVALENT CATIONS
Authors: Chen David
Published: March 2010

Aluminum-saturated Wyoming bentonite, suspended in a solution of NH4Cl, KCl, or LiCl, was adjusted to a range of degrees of base saturation with the respective hydroxide. The distribution of the cations between solution and pH-independent exchange sites could be represented satisfactorily by an equilibrium distribution equation when the monovalent ions were NH4 or K but not when they were Li. The ion product (Al) (OH)3 was smaller at low base saturation, and increased to about 10−33.0 with NH4 and K but to only 10−33.7 with Li. The monovalent base potential (pH–pM) was a function of the magnitude of (Al) (OH)3 and the distribution constant, as well as the degree of base saturation.
WATER-STABLE AGGREGATION IN RELATION TO VARIOUS CROPPING ROTATIONS AND SOIL CONSTITUENTS
Authors: Malik M. N. , Stevenson D. S. , Russell G. C.
Published: March 2010

The effects of four cropping systems on water-stable aggregation were compared. Two methods of wetting the soil, (1) by capillarity and (2) under vacuum prior to wet-sieving, were also compared. Various soil constituents were determined to assess their roles in the promotion of granulation and stability. Water-stable aggregation in grassland was significantly higher than in the other three long-term rotations, corn once in 9 years, continuous wheat, and 4 years alfalfa in 10 years. No significant differences in water-stable aggregation were found among the other three rotations.Wetting the soil by capillarity was judged to give a better index of soil aggregate stability than wetting under vacuum. Organic carbon and stable aggregation were positively correlated in the grassland soil and in the soil of the cultural treatments combined over all depths, suggesting an important role of organic matter in stabilization of soil aggregates. It is pointed out, however, that in cultivated soils the cultivation or the type of root system of the crops may override the influence of the organic carbon. Total soluble salts were positively correlated with aggregation in a few treatments.
EFFECT OF CONCENTRATION OF THE ALUMINUM ION ON ROOT DEVELOPMENT AND ESTABLISHMENT OF LEGUME SEEDLINGS
Authors: MacLeod L. B. , Jackson L. P.
Published: March 2010

Alfalfa, red clover, ladino clover, alsike clover, and birdsfoot trefoil were germinated in soil (pH 6.5) or in inert silica (8 mesh) and allowed to root in a [Formula: see text] Hoagland and Snyder's nutrient solution (pH 4.5) with 0, 0.5, 1, 2, 4, and 10 p.p.m. of added aluminum. Each species, germinated in silica, was also rooted in an unlimed acid soil (pH 4.6) and the same soil limed to a pH of 6.5.Concentration of aluminum ion remaining in solution was 0, 0.1, 0.2, 0.5, 1.0, and 2.0 p.p.m. Saturation extracts of the unlimed and limed soil contained 0.45 and 0.0 p.p.m respectively of aluminum ion in solution. The pH of the nutrient solutions with 0.5, 1, and 2 p.p.m. of added aluminum increased to 5.0 or higher in 24 hours while that with 4 and 10 p.p.m. of added aluminum remained relatively constant.Seedling weight and chemical composition of the tops and root portions varied significantly between species. Alfalfa and red clover showed the most vigorous rate of establishment, and yields were higher with 0.1 and 0.2 p.p.m. concentration of aluminum ion than with the zero treatment. Significant restriction of top and root growth of all species occurred with less than 1.0 p.p.m. of aluminum ion while 2.0 p.p.m. was toxic to root growth. Growth restrictions were more severe at 21 days after seeding than at the 28- or 32-day stages. Yield of tops and roots growing into unlimed acid soil were 73 and 71% respectively of those growing into limed soil. Aluminum taken up by the plant was concentrated in the roots and only with the concentration of aluminum at 2.0 p.p.m. was the content in the tops increased significantly. Phosphorus in the roots, which increased significantly with aluminum ion concentration, was apparently immobilized by aluminum. Percent Ca in the roots increased and in the tops decreased with increasing concentrations of aluminum. Content of K and Mg also varied with aluminum concentration.
PERMAFROST IN ORGANIC SOILS OF NORTHERN ALBERTA
Authors: Lindsay J. D. , Odynsky W.
Published: March 2010

The distribution and some of the characteristics of a frozen layer in the organic soils of northern Alberta were investigated between 1957 and 1962.The data showed that the area could be divided into three broad zones with regard to the persistence of a frozen layer in these soils. In zone A a frozen condition was found at 90% of the inspection sites at an average depth of 22 in. In zone B only 60% of the sites had a frozen layer, and were usually confined to the more shaded locations. The frozen layer in zone B was much thinner, could usually be penetrated with a steel probe, and occurred at an average depth of 24 in. The third area, zone C, was characterized by a 24-in. frozen layer in early spring, which subsequently thawed at a fairly rapid rate and usually disappeared by mid- or late-July.Zone A is described as a permafrost area for organic soils. Zone B is an area of climafrost in which the frozen condition is temporary but frequently lasts for more than 1 year, and zone C is a region of active frost in which the frozen layer exists for less than a year.
THE EXTRACTION OF EXCHANGEABLE CATIONS FROM SOILS
Authors: Clark J. S.
Published: March 2010

A study was made of techniques for the measurement of soil pH and corrected lime potential and for the extraction of exchangeable cations from soils. The experiments showed that in order to obtain stable and reliable pH values and ion concentrations it was necessary to equilibrate the soil samples in CaCl2 (0.005 to 0.02 M) for 4 to 5 days. After the soil was washed twice with water, the exchangeable cations were extracted from the equilibrated samples by shaking for 16 to 24 hours with 100 ml 2 N NaCl for 0.5 to 2.5 meq of exchangeable cations. In order to obtain reliable values for exchangeable Al with the soils studied, it was necessary to use a colorimetric method instead of titration with NaOH. When these precautions were observed the relation between corrected lime potential and percent base saturation for a number of soils agreed within reasonable experimental error with the theoretical one obtained for Wyoming bentonite.
SOME PROPERTIES OF ALUMINUM HYDROXIDE PRECIPITATED IN THE PRESENCE OF CLAYS
Authors: Turner R. C.
Published: March 2010

With Arizona bentonite, Wyoming bentonite, Fithian illite, and Georgia kaolin it was found that the OH/Al ratio of the aluminum hydroxide precipitated was about 2.7, providing the initial OH/Al ratio was not greater than 2.7. When the initial OH/Al ratio was increased to 3.0 the OH/Al ratio of the precipitate also increased to 3.0. The decrease in cation exchange capacity of the clays per milliequivalent of Al in the precipitate was independent of the initial OH/Al ratio when the ratio was varied from 1.0 to 2.7. When this ratio was increased beyond 2.7, however, inactivation of the exchange sites decreased, until with an initial OH/Al ratio of 3.0 there was very little decrease in exchange capacity. It required less precipitated Al to decrease the exchange capacity of Arizona bentonite than it did for the other three clays.
THE SEDIMENTATION TIMES USED IN THE HYDROMETER METHOD FOR MECHANICAL ANALYSIS OF SOILS
Authors: Floate M. J. S.
Published: March 2010

not available
A discrepancy between predictions of saturating nutrient uptake models and nitrogen‐to‐phosphorus stoichiometry in the surface ocean
Authors: Ballantyne Ford IV , Menge Duncan N. L. , Weitz Joshua S.
Published: March 2010

We derive a simple prediction about euphotic zone N: P stoichiometry from a large class of models that use saturating nutrient uptake functions to characterize N and P acquisition by phytoplankton. The prediction is: At an ecological steady state, the ratio of phytoplankton N: P to inorganic N: P in the euphotic zone equals the ratio of phytoplankton maximum uptake rates of N and P. We estimate this predicted ratio using nutrient uptake parameters measured in laboratory growth experiments and compare the predicted ratio to empirical observations from long‐term sampling in the Atlantic and Pacific oceans. The model predictions for the ratio of phytoplankton N: P to inorganic N: P are at odds with the majority of data from extensive long‐term sampling in the Atlantic and the Pacific oceans. This discrepancy calls into question the scope of applicability of ecosystem models that explicitly describe phytoplankton growth as a function of N and P availability. We discuss efforts to resolve this discrepancy, including the need for performing more comprehensive N and P uptake experiments and by reexamining models of nutrient uptake.
Effects of land use, urbanization, and climate variability on coastal eutrophication in the Baltic Sea
Authors: Savage Candida , Leavitt Peter R. , Elmgren Ragnar
Published: March 2010

Sedimentary records of organic matter inputs (stable nitrogen isotopes [δ15N], nitrogen [N], and carbon [C] content), phytoplankton abundance (pigments, stable carbon isotopes [δ13C]), and community composition (pigments) were used to reconstruct the history and pathway to water‐quality degradation in a Swedish Baltic coastal bay. Changes in nutrient sources and cycling began in the 1800s, but eutrophication intensified only after the 1950s, coincident with intensified agricultural practices. Specifically, sedimentary N and C content doubled, δ13C increased, and concentrations of pigments indicative of total algal biomass (ß‐carotene, chlorophyll a), diatoms (fucoxanthin, diatoxanthin), chlorophytes (lutein‐zeaxanthin, Chlorophyll b), and cyanobacteria (canthaxanthin) increased significantly after 1950. Enhanced algal abundance was most strongly related to total N influx and secondly to total P influx. In particular, historical change in algae was related to agricultural N influx and only weakly to agricultural P. In recent decades, wastewater N influx has further stimulated algal biomass, particularly diatoms. In contrast, colonial cyanobacteria were more correlated to total P than total N inputs. Variance‐partitioning analysis explained 60% of the changes in algal abundance and community composition since 1880, with diffuse and point nutrients jointly explaining 36% of the long‐term change in algal biomass. Climate variability has become more important as a factor influencing coastal eutrophication in recent decades, explaining 14% of the variance in the algal data since 1975. Both urban and agricultural sources of nutrients have degraded water quality, illustrating the need for cooperation between stakeholders at regional levels to achieve "good ecological status" in the Baltic coastal environment.
Oxygen isotopic fractionation and exchange during bacterial nitrite oxidation
Authors: Buchwald Carolyn , Casciotti Karen L.
Published: March 2010

We elucidate the controls on the δ18O values of microbially produced nitrate by tracking the δ18O of nitrite and nitrate during bacterial nitrite oxidation, which is the final step of the nitrification process. Aside from the δ18O values of the nitrite and water substrates, three factors can affect the δ18O value of nitrate produced during nitrite oxidation: (1) a kinetic isotope effect for nitrite oxidation (18εk,NO2), (2) a kinetic isotope effect for water incorporation by nitrite oxidoreductase (18εk,H2O,2), and (3) microbially mediated exchange of oxygen atoms between nitrite and water (×NOB). These parameters were quantified through batch culture experiments with species from three genera of marine nitrite‐oxidizing bacteria: Nitrococcus, Nitrobacter, and Nitrospira. Experiments conducted with 18O‐labeled water showed that less than 3% of the oxygen atoms in nitrite were exchanged with water and that 18εk,H2O,2 ranged from +12.8% to +18.2%. With the use of these parameters and the previously measured values of the δ18O of nitrite produced by ammonia‐oxidizing bacteria, the δ18O of newly produced nitrate in the ocean was estimated to fall between 28.3%to 20.7%, which is within the range necessary for balancing a deep ocean nitrate δ18O budget.
Sulfide exposure accelerates hypoxia‐driven mortalit
Authors: Vaquer-Sunyer Raquel , Duarte Carlos M.
Published: March 2010

The effect of the presence of sulfide on the survival of benthic organisms under hypoxia was tested using a meta‐analysis of published experimental results evaluating the effects of the presence of hydrogen sulfide on the median survival time of benthic macrofauna under hypoxia. The meta‐analysis confirmed that survival times under hypoxia are reduced by an average of 30% in marine benthic communities exposed to hydrogen sulfide. The effect of sulfide on survival was higher for egg forms than for juvenile or adult stages. The aggravation of the negative effects of spreading hypoxia in the presence of sulfide suggests that the threats derived from hypoxia to marine biodiversity are greater than anticipated on the basis of the direct effects of low oxygen concentration alone.
Effects of seasonality and resource limitation on organic matter turnover by Chironomidae (Diptera) in southern Appalachian headwater streams
Authors: Romito Angela M. , Eggert Susan L. , Diez Jeffrey M. , Wallace J. Bruce
Published: March 2010

Despite their high abundance, secondary production, and known reliance on detrital material, the role of chironomids (Diptera) in fine particulate organic matter (FPOM) dynamics has not been well quantified. We conducted field trials using fluorescent pigment markers to estimate seasonal rates of consumption, annual secondary production, assimilation efficiency (AE), and FPOM turnover for non‐Tanypodinae chironomids in two similar, southern Appalachian, headwater streams. An ecosystem‐level experimental manipulation of detrital inputs in one study stream allowed for a unique assessment of turnover in reference, resource‐limited, and resource‐recovery systems. Seasonality had a significant effect on larval gut‐passage time (GPT), with faster GPT at higher temperatures. Mean GPT ranged from 39 min (summer) to 67 min (winter). Mean annual FPOM turnover was reduced in the resource‐limited stream (5.5 kg ash‐free dry weight per year; 12% of mean annual FPOM export) compared to the reference stream (46 kg yr−1; 74% of mean export). Following 4 yr of resource recovery, FPOM turnover increased to 24 kg ash‐free dry wt yr−1 (16% of export) but remained lower than levels measured in the reference stream (53 kg ash‐free dry wt yr−1; 20% of export). Chironomid contribution to FPOM turnover was much higher in low vs. high discharge conditions (74% in low discharge vs. 20% in high discharge). Assimilation efficiency was estimated to be low in all systems (1.7–2.5%). Chironomids turned over a large portion of FPOM available to them, suggesting that turnover by the entire collector community in forested headwater systems may be much higher than expected.
Scavenging and retention of bismuth by marine plankton and biogenic particles
Authors: Fowler Scott W. , Teyssie Jean-Louis , Church Thomas M.
Published: March 2010

We did radiotracer experiments using 207Bi to quantify the bioavailability, accumulation, and retention of bismuth in marine plankton and biogenic detritus. The accumulation of 207Bi by two species of phytoplankton (Dunaliella tertiolecta and Emiliana huxleyi) was very rapid, approaching steady state after ~1 d. Emiliana cells without coccoliths reached a volume concentration factor (VCF) roughly twice that attained by cells with coccoliths. VCFs were 5 × 105 for Dunaliella and (4–9) × 106 for Emiliana after exposure for approximately 5 d. The radioactivity associated with Dunaliella was released with a biological half‐time of 3–5 d. Copepods (Anomalocera patersoni and Acartia species) grazing radiolabeled Dunaliella assimilated ~4% of the ingested 207Bi. Unassimilated radioactivity, voided in fecal pellets, was lost from pellets relatively slowly (half‐times of 26 d for Anomalocera and 58 d for Acartia). These release rates were similar to copepod fecal pellets that had scavenged 207Bi directly from water. Scavenging of bismuth from water by fecal pellets was considerable and extremely rapid, and uptake rates were similar to those of various size fractions of marine snow collected in a sediment trap. Release of scavenged 207Bi from the fresh fecal pellets was relatively slow, and very little release of radionuclide from the different size fractions of marine snow was observed. The biogeochemical behavior of bismuth in the marine environment closely resembles that of other particle‐reactive uranium‐thorium (U–Th) series and transuranic elements.
Effect of a flood event on the dynamics of phytoplankton and biogeochemistry in a large temperate Australian lagoon
Authors: Cook Perran L. M. , Holland Daryl P. , Longmore Andrew R.
Published: March 2010

In episodically driven estuaries, nutrient delivery is typically confined to sporadic flow events, followed by intense biogeochemical recycling of nutrients. We document the response of a temperate lagoon system with episodic winter‐ or spring‐dominated catchment inflows (Gippsland Lakes, southeast Australia) to a flood event. High winter inflows resulted in high surface‐water concentrations of inorganic nitrogen (IN; NO2− + NO3− + NH4+) relative to reactive phosphorus (RP) with an IN :RP ratio > 100. This resulted in a rapid diatom and dinoflagellate bloom, which collapsed as water column nutrients were exhausted. Increased carbon delivery to the sediment stimulated benthic respiration and depleted bottom‐water oxygen, which led to a large release of RP from the sediments, decreasing the IN :RP ratio in the bottom water to ~6. Strong stratification of the water column allowed the accumulation of RP in the bottom water over spring and into summer. Mixing of RP from the bottom water over summer triggered the development of a Nodularia spumigena Mertens bloom. As such, the nutrient supply for the Nodularia bloom was through a biogeochemical filter that strongly favored N2‐fixing cyanobacterial blooms by reducing IN :RP ratios through a combination of sediment denitrification and release of stored phosphorus from within the sediment. These observations lead us to the paradoxical conclusion that high nitrogen loading over winter contributed to severe nitrogen limitation over summer, and highlight the importance of controlling both nitrogen and phosphorus loading to estuaries.
Living at the border: A community and single‐cell assessment of lake bacterioneuston activity
Authors: Hörtnagl Paul , Pérez Mariá Teresa , Sommaruga Ruben
Published: March 2010

We assessed the physicochemical properties of the surface microlayer (SML: first 900 µm) and its underlying water (ULW: 0.2–0.5‐m depth) and compared the composition and activity of their bacterial communities in six lakes located across an altitude gradient. Activity was assessed at both the community level, by measuring leucine bulk incorporation, and at the single‐cell level, by using microautoradiography. Catalyzed reporter deposition fluorescence in situ hybridization was used to quantitatively assess the structure of the bacterial assemblage. Dissolved organic matter at the SML was significantly enriched in small‐size molecules as compared to the ULW. Bacterial abundance in the SML ranged from 3.2 × 105 cells mL−1 to 3.2 × 106 cells mL−1 and was enriched in four out of six lakes when compared to the ULW. The SML and ULW showed lake‐specific differences in bacterial community composition, although in most cases, both layers were dominated by Betaproteobacteria. This group also contributed the most to total activity in both layers in all lakes, followed by Actinobacteria. Despite large differences in environmental conditions among lakes, the fraction of active neustonic bacteria was very similar in most of them. Both bulk and single‐cell activities are not necessarily lower in the SML than in the ULW, and well‐adapted bacteria exist in the extreme conditions found in this habitat.
Unraveling the role of land use and microbial activity in shaping dissolved organic matter characteristics in stream ecosystems
Authors: Williams Clayton J. , Yamashita Youhei , Wilson Henry F. , Jaffé Rudolf , Xenopoulos Marguerite A.
Published: March 2010

Surface water samples were collected from 43 streams distributed throughout watersheds of mixed land use in southern Ontario, Canada. Absorbance and fluorescence spectroscopy with parallel factor analysis (PARAFAC) was used to characterize dissolved organic matter (DOM). DOM characteristics were related to environmental variables, microbial activity indicators (bacterial production and extracellular leucine aminopeptidase activity), and riparian land use to understand better how these factors influence DOM in streams. PARAFAC produced a six‐component model (C1 to C6). Temperature correlated with each PARAFAC component, suggesting that water source, drainage area, and light penetration broadly affected DOM characteristics. C1 and C2 represented terrestrial, humic‐like DOM fluorophore groups and comprised 41–65% of stream DOM fluorescence. C5, a tryptophan‐like component, related negatively to a humification index but positively to leucine‐aminopeptidase activity and recently produced DOM, suggesting that C5 consisted of autochthonous, microbially produced DOM. C3, C4, and C6 showed signs of quinone‐like, humic‐like, and microbial transformable fluorophores. The distribution of these potentially redox‐active PARAFAC components indicated that DOM was in a more reduced state in streams with higher bacterial production and agricultural land use than in streams with increased wetlands area, which had greater relative abundance of the oxidized quinone‐like component. Anthropogenic land use and microbial activity altered the quantity and quality of DOM exported from human‐affected streams from that observed in forest‐ and wetland‐dominated streams. DOM in agriculturally affected streams was likely more labile and accessible to the microbial community than DOM in wetland streams, which supported low rates of microbial activity.
Underestimation of rotifer abundance a much greater problem than previously appreciated
Authors: Chick John H. , Levchuk Alex P. , Medley Kim A. , Havel John H.
Published: March 2010

Although rotifers are important components of aquatic food webs and suitable sampling methods have been described and tested in the peer‐reviewed literature, they are frequently overlooked or quantified with improper methods (e.g., mesh sizes ≥ 63 µm) in freshwater ecology studies. As a result, we believe that the role of rotifers in aquatic food webs and ecosystem processes remains underappreciated, and this conceptual shortfall is exacerbated by the continued use of improper sampling methodology.We examined density and biomass estimates of metazoan zooplankton in the Upper Mississippi and Missouri rivers from two sampling methods. The macrozooplankton method was designed to target cladocerans, adult and juvenile copepods, by filtering 180 L water through a 63‐µm mesh. The microzooplankton method was designed to target rotifers and copepod nauplii by filtering 18 L water through a 20‐µm mesh. The macrozooplankton method underestimated the density and biomass of common rotifers by two to three orders of magnitude, a far greater amount of error than reported in previous studies. This bias in density estimates for rotifers decreased with increasing mean length of rotifers. The microzooplankton method proved to be ineffective for quantifying cladoceran species richness or cladoceran density at the species level. We urge aquatic ecologists to match their sampling methodology with the specific goals of their study. An accurate understanding of the role of rotifers in freshwater ecosystems will only be possible when the use of appropriate methodology becomes the rule rather than the exception.
Damage and recovery assessment of vessel grounding injuries on coral reef habitats by use of georeferenced landscape video mosaics
Authors: Lirman D. , Gracias N. , Gintert B. , Gleason A. C. R. , Deangelo G. , Dick M. , Martinez E. , Reid R. P.
Published: March 2010

Vessel groundings are a major source of disturbance to coral reefs worldwide. Documenting the extent of damage caused by groundings is a crucial first step in the reef restoration process. Here, we describe the application of a novel survey methodology, landscape video mosaics, to assessment of the damage caused by vessel groundings. Video mosaics, created by merging thousands of video frames, combine quantitative and qualitative aspects of damage assessment and provide a georeferenced, landscape, high‐resolution, spatially accurate permanent record of an injury. The scar in a Florida reef impacted by a 49‐foot vessel, imaged in 2005 and 2006, covered an area of 150 m2 (total imaged area was >600 m2). The impacted coral community showed limited signs of coral recovery more than 3 years after the initial impact; the cover of corals was still significantly higher in the undamaged areas compared to the scar. However, seagrass colonization of the scar was observed. Finally, no evidence of further physical impacts was documented even when four hurricanes passed near the grounding site in 2005. The video mosaics developed in this study proved to be ideal tools to survey the grounding scars. Mosaics provide a means to collect information on the size of the damage area and the status and trends of the impacted biological communities and provide a permanent visual record of the damage, thereby expanding the quality and diversity of information that can be collected during field surveys.
How useful are progressive vector diagrams for studying coastal ocean transport?
Authors: Carlson Daniel F. , Muscarella Philip A. , Gildor Hezi , Lipphardt Bruce L. , Fredj Erick
Published: March 2010

Progressive vector diagrams (PVDs) have been used to estimate transport in the coastal ocean from point measurements of velocity time series, although they strictly only approximate true particle trajectories in regions where the currents are spatially uniform. Currents in most coastal regions vary significantly in both space and time, making coastal transport estimates from PVDs questionable. Here, we used synoptic surface currents measured over periods of several months by HF radars in two coastal areas with distinctly different circulation features (the Gulf of Eilat, a deep, semi‐enclosed basin, and the Delaware Bay mouth, a coastal estuarine outflow) to assess the time scales over which PVD paths computed from velocity time series at fixed points separate from particle trajectories computed from two‐dimensional measured horizontal currents that vary in both space and time. In both study regions, PVDs and particle trajectories separate by 1 km over a mean time period of 7–10 h with no significant month‐to‐month variation in either region. The separation time statistics presented here should serve as a strong caution for investigators motivated to estimate transport using only point measurements.
Viability of the Use of the Sand Dollar Mellita quinquiesperforata as a Test Organism
Authors: Laitano Kalinka dos Santos , Gonçalves C. , Resgalla Jr. Charrid
Published: March 2010

The aim of this study was to investigate the viability of the use of sand dollar Mellita quinquiesperforata as a test organism in chronic experiments over short durations. For this, the protocol of the CETESB Technical Standard was used, which was designed for the regular sea urchin Lytechinus variegatus, using embryos and larvae exposed to four reference toxins, for a 24-hour period. The substances used in the toxicity tests were zinc sulfate, potassium dichromate, copper sulfate and sodium dodecyl sulfate (SDS). These substances are normally used to evaluate the relative sensitivity of marine test organisms, and to estimate the precision and reliability of the data produced in the laboratory. The proposed protocol proved to be adequate for its use with the irregular sea urchin M. quinquiesperforata, some modifications being necessary in terms of the validation requirements, due to the low egg production, low fecundation rate, and higher percentage of effect observed in the control flasks. The EC50;24h average for zinc was 50 μm L–1 (VC of 44% for n = 5), for chrome it was 1462 μg L–1 (VC of 25% for a n of 3), for copper it was 10 μg/L–1 (VC of 35% for n = 5) and for SSD it was 2145 μg L–1 (n = 2). M. quinquiesperforata presents a sensitivity similar to species registered by the NBR/ABNT, demonstrating the potential of this Echinodermate for use as a test organism, in cases where it is impossible to use species required by the environmental agencies.
Evaluation of Toxicity Endosulfan Sulfate on Danio rerio Juveniles (Cypriniformes, Cyprinidae)
Authors: Fracácio Renata , Campagna A. F. , Rodrigues B. K. , Verani N. F. , Espíndola E. L. G.
Published: March 2010

The objective of this work was to evaluate the toxicity of endosulfan sulfate toxicity (the most persistent form) in Danio rerio juveniles, considering the mortalities, in exposition of 96 hours, and survival and microscopic gill morphology in toxicity test partial chronic (7 days) in concentrations of 0.003 μg L–1, 0.3 μg L–1 and 3.0 μg L–1, near the levels detected in the upper Jacaré-Guaçu river basin (São Paulo, Brazil). The result of the mortality was detected CL50, 96 h of the 7.29 μg L–1. Considering the survival, only the higher concentration (3 μg L–1) promoted toxicity to the test organisms. However, the histological analyses revealed gill changes such as hyperplasia, fusion between some secondary lamellae and thickening of the apex of some secondary lamellae. These alterations compromised the gases exchange and consequently the vital functions of the biological system. The obtained alterations were of first and second level, but these changes can either to return to normal conditions when chemistry conditions improve, or to progress to a third stage degree, which are irreversible, provoking the death of the individual. This results prove the importance of the histology as a tool to evaluate toxicity of chemical products, giving evidences that endosulfan sulfate is toxic to this fish specie at concentrations found in aquatic environments.
Acute Toxicity and Histopathological of Reward® Herbicide on Gill and Liver of Pacu (Piaractus mesopotamicus)
Authors: Henares Matheus N. P. , Cruz Claudinei da , Gomes G. R. , Pitelli R. A. , Machado M. R. F.
Published: March 2010

The lethal concentration of 50% (LC(I)50;96h) and the hystopathological effects of the herbicide Reward® on the pacu fish (Piaractus mesopotamicus) were evaluated under three laboratory assays. The fishes were submitted to 0; 0.27; 0.31; 0.39; 0.43; and 0.48 ml of Reward® L–1 and gills and livers histologies were evaluated on the surviving fishes. The Reward® CL(I)50;96h estimated was of 0.34 mL L–1. In the treatments control and the 0.27 mL L–1 no histopathological alterations in the gills and livers of the exposed fishes were found. On the gills, the 0.31 and 0.35 mL L–1 treatment caused subepithelial edema in the secondary lamellas coating cells. In the 0.39 mL L–1 and 0.43 mL L–1 treatments, hyperplasia of the coating cells and apical fusion of the secondary lamellae were observed. On the liver, the 0.31, 0.35 and 0.39 mL L–1 treatment caused diarrhea, hypertrophia and the presence of glycogen granules inside the hepatocytes, respectively. In the 0.43 mL L–1 treatment hepatocytes necrosis was registered. The Reward® herbicide was not very toxic on the pacu and the most severe histopathological alterations like fusion of secondary lamellas on gills and necrosis of hepatocytes were noticed only on higher evaluated concentrations.
Sensibility of Neotropical Fishes to Dichromate of Potassium
Authors: Cruz Claudinei da , Cubo P. , Gomes G. R. , Venturini F. P. , Guilherme P. E. , Pitelli R. A.
Published: March 2010

The objective of this study was to evaluate the sensitivity of potassium dichromate to Piaractus mesopotamicus (pacu), Hyphessobrycon eques (mato-grosso) e Phallocerus caudimaculatus (guaru). The LC(I)50;96h for the P. mesopotamicus was 144.50 ± 19.67 mg L-1; for the H. Eques, 130.79 ± 10.02 mg L-1; and for the P. Caudimaculatus, of 154.39 ± 6.72 mg L-1. The three species showed potencial for use as organims-tests, however, the H. eques met the criteria for best selection.
Cholinesterase Activity in the Head of Wild Poecilia reticulata from Bahia, Brazil: Biochemical Characterization, Effects of Sample Storage and Normal Range of Activity
Authors: Stringuetti C. , Guilhermino L. , Silva Eduardo Mendes da
Published: March 2010

In this study, the soluble cholinesterases (ChE) from the head of Poecilia reticulata from a wild population of Bahia, Brazil were characterized using different substrates (acetylthiocoline, butyrylthiocoline and proprionylthiocoline) and selective inhibitors (eserine sulphate, iso-OMPA and BW284C51). Possible effects of time (1, 2, 3, and 4 weeks) and different storage temperatures (freezer storage at ca. –20ºC and –50ºC, and liquid nitrogen system at –196ºC) on ChE activity were also investigated, together with the normal range of ChE activity of non-exposed individuals. The results for the enzymatic characterization indicate that the enzyme present in the head of P. reticulata was mainly acetylcholinesterase. The mean and standard deviation of activity found in non-exposed wild males collected in different periods of the year were 149.71 ± 7.72 SD U/mg protein, respectively. ChE activity significantly decreased after the seventh day of sample storage, independently of the temperature.
Cymatium parthenopeum parthenopeum (von Salis, 1793) (Mesogastropoda: Ranellidae): A New Bioindicator of Organotin Compounds Contamination?
Authors: Costa M. B. , Otegui M. B. P. , Barbiero D. C. , Costa Mercia Barcellos da
Published: March 2010

This work reports the occurrence of imposex in the mesogastropod Cymatium parthenopeum parthenopeum in the coast of Espírito Santo (Southeastern Brazil) and evaluates the possible use of this species as a bioindicator of organotins (OTs) contamination. A total of 53 adult specimens were sampled at Formosa beach nearby the Vitoria main marina, which is a critical area for this kind of contamination. The animals were analyzed using a non-destructive protocol and a sub-sample of 7 animals (6 imposexed females and 1 control male) were dissected for a more detailed observation. Imposex development was observed in 39 out of 44 sampled females. Imposexed females showed pre-penis and penis development, but a vas deferens development similar to that of the males was not observed. No sign of sterility was found. A comparison with data from other species in this area indicates that C. parthenopeum parthenopeum, although less sensitive to imposex induction, can be used as biological indicator of OTs contamination.
Supporting Information and Challenges in the Establishment of Irrigation Water Quality Criteria for Chemicals
Authors: Valente-Campos Simone , Umbuzeiro Gisela de Aragão , Nascimento E. S.
Published: March 2010

Due to contamination of water sources, maximum allowed concentration levels have been established for each individual use of water, in order to guarantee their quality (drinking water, waters for irrigation, livestock, recreation among others). Brazil has established chemical water quality criteria only for drinking water (potability). Irrigation represents one of the most important uses of water in Brazilian territory. This study presents the methodology used for calculation of water quality criteria and the main difficulties in their establishment. It was verified that irrigation water quality criteria are based on phytotoxicity data, do not depend on water origin, and the differences observed for the various regulations can be explained by differences in irrigation rates and plant species considered. The choice of plant species and chemicals that should be included in the regulations depends on their regional importance, which confirms the need of establishment of proper irrigation water quality criteria for each country.
Determination of Uranium in Samples of Perna perna Mussel Transplanted Along the São Paulo Seashore, by Epithermal Neutron Activation Analysis (ENAA)
Authors: Seo Daniele , Catharino M. G. M. , Moreira E. G. , Saiki M. , Vasconcellos M. B. A. , Pereira C. D. S. , Sousa E. C. P. M.
Published: March 2010

Bivalve mussels are being used in many studies, for biomonitoring purposes, in coastal regions, due to their capacity of accumulating pollutants. This paper presents the results obtained for uranium determinations in samples of mussels of the Perna perna species (Linnaeus, 1758), transplanted along the northern seashore of the State of São Paulo, Brazil. Mussels produced at a cultivation site in the Cocanha Beach, in Caraguatatuba (control site) were transplanted, in all seasons of the year, to four different sites: Engenho d‘Água Beach, in Ilhabela; Almirante Barroso Terminal (TEBAR), in São Sebastião; e Palmas Island and Itaipu, in the Santos Bay. For uranium determination, the method of epithermal neutron activation analysis (ENAA) was used and for analytical quality control the reference materials NIST SRM 1566b Oyster Tissue and NIST SRM 1575 Pine Needles were used. The results obtained in these materials were in good agreement with the certified values (percentages of error less than 2.2%) and presented good precision (relative standard deviations below 3.3%). The uranium concentrations in mussel samples varied from 40.8 to 101.1 μg kg–1 (dry weight). The comparison among the uranium concentrations obtained in the different sites of transplantat indicated that the region of Santos has the highest and the lowest concentration of U, depending on the period of exposure of the samples of mussels.
Erratum: Kidney Histology of Mice After Seven Days Oral Intake of Cyanobacterial Extract
Authors: Carvalho Elisa Garcia , Sotero-Santos R. B. , Martinez C. B. R. , Freitas E. C. , Fenerich-Verani N. , Dellamano-Oliveira M. J. , Rocha O.
Published: March 2010

Erratum to "Kidney Histology of Mice After Seven Days Oral Intake of Cyanobacterial Extract" [J. Braz. Soc. Ecotoxicol. 2 (2007) 39-43].
Bismuth and Bismuth Alloys
Authors: Chagnon Mark J.
Published: March 2010

Bismuth is a very brittle, silvery metal having a high metallic luster. It is next to lead in the periodic table of elements. Bismuth is considered nontoxic despite the fact that it has a heavy‐metal status.

Bismuth is a minor metal in that it is usually mined as a by‐product and not for its own intrinsic value. It is usually a by‐product of copper or lead ores. However there are two mines that mine bismuth ore, one is in China and the other is the Tasna mine in Bolivia.The United States ceased production of bismuth in 1997. Bismuth is recovered by the Betterton‐Kroll process, Betts electrolytic process, and is recovered from tin concentrates. Bismuth has a wide variety of applications. It is used for metallurgical additives, in pharmaceuticals and in fusible alloys, solders, and ammunitions, Bismuth is used in over‐the‐counter stomach remedies and is thus considered safe. Bismuth alloys are discussed in detail.
Cheminformatics
Authors: Villar Hugo O.
Published: March 2010

This article provides an introductory overview of some salient aspects of a field that is becoming mission critical to chemical research. As the volume of data generated by all chemistry projects continues to expand, management, analysis, visualization and dissemination of the data has to be automated. Cheminformatics deals with the complex issues that result from this data explosion and the applications that have been generated.
Phthalein Dyes
Authors: Sabnis Ram W.
Published: March 2010

Color change has fascinated individuals for a long time. Phthaleins dyes traditionally are used for color change, and they constitute the major class of pH indicators. This review presents systematic and up‐to‐date compiled data on commonly used phthalein dyes with references to the introduction, history, chemical structures, synthesis, color‐change mechanism, color and constitution, spectral data, applications, and health/safety factors.

Phthalein dyes exhibit multiple applications, which are grouped into eight major categories such as electronics, security, coatings, industrial, agriculture, food, personal‐care products, and medical. The toxicity of phenolphthein is discussed with references to bacterial toxicity, carcinogenicity, lung cancer, ovarian cancer, chromosome aberrations, cytotoxicity, DNA damage, environmental toxicity, estrogen activity, genotoxicity, mutagenicity, renal toxicity, and reproductive toxicity.