Insurface Waters Research Articles

VALIDAÇÃO DE MÉTODO ANALÍTICO PARA QUANTIFICAÇÃO DOS ESTRÓGENOS NATURAIS (E1, E2 E E3) E SINTÉTICO (EE2) EM ÁGUA SUPERFICIAL E MATERIAL PARTICULADO EM SUSPENSÃO DE UM ESTUÁRIO SUBTROPICAL DO ATLÂNTICO SUL, BRASIL

VALIDATION OF ANALYTICAL METHOD FOR QUANTIFICATION OF NATURAL ESTROGENS (E1, E2, AND E3) AND SYNTHETIC (EE2) IN SURFACE WATERS AND SUSPENDED PARTICULATE MATERIAL OF A SOUTH ATLANTIC SUBTROPICAL ESTUARY, BRAZIL. Marine pollution has become relevant for coastal conservation units and ecosystems of great ecological importance. This study validated analytical methods to investigate the occurrence of the emerging contaminants 17β-estradiol (E2), estrone (E1), estriol (E3), and 17α-ethinylestradiol (EE2) in surface waters and suspended particulate matter (SPM) from Guaratuba Bay, South Atlantic, Brazil. The analysis was performed by liquid chromatography coupled to a fluorescence detector (LC-FLD) after pre-concentration of surface water samples by solid phase extraction (SPE) or solid-liquid extraction for SPM samples. The recovery percentages were between 48 and 87%, and the coefficient of variation (CV) between 3 and 24% for SPM and from 64 to 107% (CV of 4 to 42%) for surface water. The method thus proved to be accurate and precise at the concentrations studied (ng g-1 and µg L-1). The concentration ranged from 10 to 177 ng L-1 in surface waters and from 392 to 4108 ng g-1 in SPM. E2, EE2, and E3 were found in SPM under different climatic conditions and population occupation. EE2 was determined in all sampling campaigns, especially in summer, when the number of tourists increases considerably. The presence of EE2 in the SPM of Guaratuba Bay warns for possible implications for the health of coastal environments.

HEAVY METAL LEVELS IN WATER, SEDIMENT AND BIOACCUMULATION INDEX IN FISH (Chrysicthys walkeri) FROM WARRI RIVER

Bioaccumulation of any heavy metal above its maximum limits invariably results tothe detrimental health of an organism. This present study was carried out to evaluatethe levels of eight heavy metals (Fe, Pb, Mn, Ni, Cu, Zn, Cr and Cd) in surface water,sediment and bioaccumulation index of (Chrysicthys walkeri) from Warri River, DeltaState, Nigeria. Samples were collected between the period of July to September,2015 from two designated stations. The order of heavy metal mean rank profile, insurface water, sediment and fish were Pb>Mn>Fe>Zn>Cr>Cd>Ni>Cu;Fe>Zn>Ni>Cu>Mn>Cd>Pb>Cr and Pb>Ni>Zn>Mn>Cd>Fe>Cr>Cu respectively.When compared with regulatory standards of WHO, FAO and FEPA threshold limitmost of the metals were above the limits for both water, sediment and fish Tissue.The bioaccumulation index of fish were above BI ? 1.0 indicating possibility ofecological concern. These findings implies that Warri River is polluted andconsumption of these fishes could have grave health consequences even with theexcellent condition factor of the fishes. Therefore, the input of pollutants into this rivershould be monitored in order to avoid associated risks

Controls on nitrite oxidation in the upper Southern Ocean: insights from winter kinetics experiments in the Indian sector

Abstract. Across the Southern Ocean in winter, nitrification is the dominant mixed-layer nitrogen cycle process, with some of the nitrate produced therefrom persisting to fuel productivity during the subsequent growing season. Because this nitrate constitutes a regenerated rather than a new nutrient source to phytoplankton, it will not support the net removal of atmospheric CO2. To better understand the controls on Southern Ocean nitrification, we conducted nitrite oxidation kinetics experiments in surface waters across the western Indian sector in winter. While all experiments (seven in total) yielded a Michaelis–Menten relationship with substrate concentration, the nitrite oxidation rates only increased substantially once the nitrite concentration exceeded 115±2.3 to 245±18 nM, suggesting that nitrite-oxidizing bacteria (NOB) require a minimum (i.e., “threshold”) nitrite concentration to produce nitrate. The half-saturation constant for nitrite oxidation ranged from 134±8 to 403±24 nM, indicating a relatively high affinity of Southern Ocean NOB for nitrite, in contrast to results from culture experiments. Despite the high affinity of NOB for nitrite, its concentration rarely declines below 150 nM in the Southern Ocean's mixed layer, regardless of season. In the upper mixed layer, we measured ammonium oxidation rates that were two- to seven-fold higher than the coincident rates of nitrite oxidation, indicating that nitrite oxidation is the rate-limiting step for nitrification in the winter Southern Ocean. The decoupling of ammonium and nitrite oxidation, combined with a possible nitrite concentration threshold for NOB, may explain the non-zero nitrite that persists throughout the Southern Ocean's mixed layer year-round. Additionally, nitrite oxidation may be limited by dissolved iron, the availability of which is low across the upper Southern Ocean. Our findings have implications for understanding the controls on nitrification and ammonium and nitrite distributions, both in the Southern Ocean and elsewhere.

Calibration of temperature-dependent ocean microbial processes in the cGENIE.muffin (v0.9.13) Earth system model

Abstract. Temperature is a master parameter in the marine carbon cycle, exerting a critical control on the rate of biological transformation of a variety of solid and dissolved reactants and substrates. Although in the construction of numerical models of marine carbon cycling, temperature has been long recognised as a key parameter in the production and export of organic matter at the ocean surface, its role in the ocean interior is much less frequently accounted for. There, bacteria (primarily) transform sinking particulate organic matter (POM) into its dissolved constituents and consume dissolved oxygen (and/or other electron acceptors such as sulfate). The nutrients and carbon thereby released then become available for transport back to the surface, influencing biological productivity and atmospheric pCO2, respectively. Given the substantial changes in ocean temperature occurring in the past, as well as in light of current anthropogenic warming, appropriately accounting for the role of temperature in marine carbon cycling may be critical to correctly projecting changes in ocean deoxygenation and the strength of feedbacks on atmospheric pCO2. Here we extend and calibrate a temperature-dependent representation of marine carbon cycling in the cGENIE.muffin Earth system model, intended for both past and future climate applications. In this, we combine a temperature-dependent remineralisation scheme for sinking organic matter with a biological export production scheme that also includes a dependence on ambient seawater temperature. Via a parameter ensemble, we jointly calibrate the two parameterisations by statistically contrasting model-projected fields of nutrients, oxygen, and the stable carbon isotopic signature (δ13C) of dissolved inorganic carbon in the ocean with modern observations. We additionally explore the role of temperature in the creation and recycling of dissolved organic matter (DOM) and hence its impact on global carbon cycle dynamics. We find that for the present day, the temperature-dependent version shows a fit to the data that is as good as or better than the existing tuned non-temperature-dependent version of the cGENIE.muffin. The main impact of accounting for temperature-dependent remineralisation of POM is in driving higher rates of remineralisation in warmer waters, in turn driving a more rapid return of nutrients to the surface and thereby stimulating organic matter production. As a result, more POM is exported below 80 m but on average reaches shallower depths in middle- and low-latitude warmer waters compared to the standard model. Conversely, at higher latitudes, colder water temperature reduces the rate of nutrient resupply to the surface and POM reaches greater depth on average as a result of slower subsurface rates of remineralisation. Further adding temperature-dependent DOM processes changes this overall picture only a little, with a slight weakening of export production at higher latitudes. As an illustrative application of the new model configuration and calibration, we take the example of historical warming and briefly assess the implications for global carbon cycling of accounting for a more complete set of temperature-dependent processes in the ocean. We find that between the pre-industrial era (ca. 1700) and the present (year 2010), in response to a simulated air temperature increase of 0.9 ∘C and an associated projected mean ocean warming of 0.12 ∘C (0.6 ∘C in surface waters and 0.02 ∘C in deep waters), a reduction in particulate organic carbon (POC) export at 80 m of just 0.3 % occurs (or 0.7 % including a temperature-dependent DOM response). However, due to this increased recycling nearer the surface, the efficiency of the transfer of carbon away from the surface (at 80 m) to the deep ocean (at 1040 m) is reduced by 5 %. In contrast, with no assumed temperature-dependent processes impacting production or remineralisation of either POM or DOM, global POC export at 80 m falls by 2.9 % between the pre-industrial era and the present day as a consequence of ocean stratification and reduced nutrient resupply to the surface. Our analysis suggests that increased temperature-dependent nutrient recycling in the upper ocean has offset much of the stratification-induced restriction in its physical transport.

MÉTODO ANALÍTICO PARA DETERMINAÇÃO DOS CORANTES AURAMINA EM TESTES DE ECOTOXICIDADE E EM ÁGUAS SUPERFICIAIS

ANALYTICAL METHOD FOR DETERMINATION OF AURAMINE DYES IN ECOTOXICITY TESTS AND IN SURFACE WATERS. Dyes can be considered important environmental contaminants. Auramine dyes, known commercially as Solvent Yellow 34 and Basic Yellow 2, are used in several industrial products, including textile and paper. In this study, an analytical method was developed and validated using Liquid-Liquid Extraction and High-Performance Liquid Chromatography coupled to Diode Array Detector (LLE and HPLC-DAD) to determine the exposure concentrations in the ecotoxicological tests with auramine dyes, increasing the results reliability about the hazard of these compounds. The method was also used to monitor auramine dyes in surface water samples, in a region considered one of the most critical regions for dyes contamination in Brazil. The results showed no risk for the aquatic organisms considering the analyzed samples. The method using simple instrumentation showed the results of selectivity, linearity (R2 > 0.99), precision (CV: 5.6-29%) and accuracy (recovery: 82-90%) considered satisfactory for the two purposes with Instrumental LOQ of the 12 µg L-1 and the Method LOQ of the 12 ng L-1. The results indicated that the proposed method was effective and practical for the auramine determination in environmental levels and will be an important tool to verify the potential risk of auramine dyes in future studies.

Analysis and Characterization of Microplastic from Personal Care Products and Surface Water in Bangi, Selangor

Primary microplastics which include microbeads are added into cosmetics and personal care products as scrubbing agent and mostly used because of their uniformity and effective exfoliating properties. However due to their small size, microplastic cannot be filtered by the water treatment plant and flow into our waterways posing a great threat to the aquatic life. Therefore, this study aims to detect the presence of microplastics in personal care products and surface water. Microplastic from personal care samples were extracted using warm water at 60 ⁰C and then characterized using ATR - FTIR to determine the polymer composition. Based on the spectrum, the extracted microplastics were confirmed as polyethylene with significance peaks at 2800 - 2900 cm-1 (C-H stretching) and medium band at 700 cm-1 which indicates the presence of ethylene networks. The extracted microplastics were also identified as polystyrene with the important peaks appear at 3300 and 1600 cm-1 with additional weak peak at 1400 cm-1 which represent C-H aromatic stretching and C=C aromatic group, respectively. Next, SEM method was used to determine the morphology and size of the microplastics which give sizes ranging from 200-500 µm for each sample. Furthermore, optical microscope was used to determine the color and shape of the microbeads. The results showed that extracted microbeads come from various colors such as white, purple, pink, brown and colorless while the shape observed was spherical, granular, and irregular. Next, insect net and bucket techniques were used in sampling of surface water. The successfully filtered solids were analysed using WPO method and characterize by ATR-FTIR technique. The microplastics found in surface water sample were from various shape including fragment, film, pellet, foam, and tube with the majority come from PE type polymer plastic. Hence, this study proved the presence of microplastic in personal care products that available in Malaysia as well as in surface water.

Addition of Thiourea Host Monomer to Polymer Flocculants to Improve Selectivity of Phosphate Sorption

Inorganic phosphate is a common nutrient that is applied as a fertilizer to both agricultural fields as well as urban settings such as private yards, public parks and other urban landscaping. While phosphate typically binds tightly to soil, movement of phosphate off of application sites can occur through soil erosion. The soil and its bound phosphate can then end up in surface waters such as rivers and lakes. Phosphate found in surface water bodies exists both as bound to the suspended clay as well as that free in solution. Elevated phosphate concentration in surface waters can lead to algal blooms and eutrophication. While the phosphate bound to clay in suspension in surface water bodies can be removed by commercially available polymer flocculants, the phosphate that is free in solution is more challenging as it is usually found in low concentrations and other anionic salts are generally present in higher concentrations. To remove phosphate from contaminated water systems, where other anions exist at higher concentrations, it is favorable to have a method of removal that is selective for phosphate. As a proof of principle, thiourea derivatized polymer flocculants were examined for the selective removal of phosphate in the presence of competing anions. The polymer flocculants exhibited selectivity for phosphate through hydrogen bonding and were effective at removing up to 43% of phosphate from simulated wastewater. Computational studies and 1H NMR were used to investigate the selectivity of the thiourea monomer for phosphate over competing anions such as chloride and sulfate.

INDICATORS OF MANGANESE IN SERUM OF WOMEN WITH POLYCYSTIC OVARY AND ANALYSIS OF POSSIBLE SOURCES OF EXPOSURE

The goal of the work. Determine the level of manganese exposure in women withpolycystic ovary (PCOS) and analyze possible sources of exposure.Material and methods. The research was conducted in Kyiv. The first group (control)consisted of 38 women of reproductive age. The second group consisted of 52 women inwhom PCOS had been diagnosed. Using ICP-MS, a study of serum manganese in bothgroups of women was conducted. The study of environmental pollution with manganesewas carried out by processing data published in the open sources of information.Results. In women with PCOS, manganese values (median - 0.0095 mg/l, 95 percentile -0.13 mg/l) in serum were elevated, which significantly exceeded values from the controlgroup (median - 0.0035 mg/l, 95 -procetylene - 0.014 mg/l, p = 0.0012). Investigation ofpossible sources of exposure showed that drinking water could not be the cause ofexposure to manganese. Indicators of manganese in surface waters exceed the maximumpermissible values from 3,2 to 28 times. The level of air pollution by manganese inhundreds of times exceeded the safe levels for humans. Current article reviews differentpathogenic mechanisms of high concentration influence of manganese on PCOSoccurrence based on the type of exposure.Conclusion. High manganese concentrations in serum were found in women with PCOS.Sources of women's exposure are connected, probably, with high level of manganese insurface waters and air pollution. Both inhalatory and nutrient manganese exposurecreate pathogenic basis for PCOS.

Patterns of suspended particulate matter across the continental margin in the Canadian Beaufort Sea during summer

Abstract. The particulate beam attenuation coefficient at 660 nm, cp(660), was measured in conjunction with properties of suspended particle assemblages in August 2009 within the Canadian Beaufort Sea continental margin, a region heavily influenced by freshwater and sediment discharge from the Mackenzie River, but also by sea ice melt. The mass concentration of suspended particulate matter (SPM) ranged from 0.04 to 140 g m−3, its composition varied from mineral to organic dominated, and the median particle diameter determined over the range 0.7–120 µm varied from 0.78 to 9.45 µm, with the fraction of particles <1 µm in surface waters reflecting the degree influenced by river water. Despite this range in particle characteristics, a strong relationship between SPM and cp(660) was found and used to determine SPM distributions across the shelf based on measurements of cp(660) taken during summer seasons of 2004, 2008, and 2009. SPM spatial patterns on the stratified shelf reflected the vertically sheared two-layer estuarine circulation and SPM sources (i.e., fluvial inputs, bottom resuspension, and biological productivity). Along-shelf winds generated lateral Ekman flows, isopycnal movements, and upwelling or downwelling at the shelf break. Cross-shelf transects measured during three summers illustrate how sea ice meltwater affects river plume extent, while the presence of meltwater on the shelf was associated with enhanced near-bottom SPM during return flow of upwelled Pacific-origin water. SPM decreased sharply past the shelf break with further transport of particulate matter occurring near the bottom and in interleaving nepheloid layers. These findings expand our knowledge of particle distributions in the Beaufort Sea controlled by river discharge, sea ice, and wind, each of which is sensitive to weather and climate variations.

Main drivers of transparent exopolymer particle distribution across the surface Atlantic Ocean

Abstract. Transparent exopolymer particles (TEPs) are a class of gel particles, produced mainly by microorganisms, which play important roles in biogeochemical processes such as carbon cycling and export. TEPs (a) are colonized by carbon-consuming microbes; (b) mediate aggregation and sinking of organic matter and organisms, thereby contributing to the biological carbon pump; and (c) accumulate in the surface microlayer (SML) and affect air–sea gas exchange. The first step to evaluate the global influence of TEPs in these processes is the prediction of TEP occurrence in the ocean. Yet, little is known about the physical and biological variables that drive their abundance, particularly in the open ocean. Here we describe the horizontal TEP distribution, along with physical and biological variables, in surface waters along a north–south transect in the Atlantic Ocean during October–November 2014. Two main regions were separated due to remarkable differences: the open Atlantic Ocean (OAO, n=30), and the Southwestern Atlantic Shelf (SWAS, n=10). TEP concentration in the entire transect ranged 18.3–446.8 µg XG eq L−1 and averaged 117.1±119.8 µg XG eq L−1, with the maximum concentrations in the SWAS and in a station located at the edge of the Canary Coastal Upwelling (CU), and the highest TEP to chlorophyll a (TEP:Chl a) ratios in the OAO (183±56) and CU (1760). TEPs were significantly and positively related to Chl a and phytoplankton biomass, expressed in terms of C, along the entire transect. In the OAO, TEPs were positively related to some phytoplankton groups, mainly Synechococcus. They were negatively related to the previous 24 h averaged solar irradiance, suggesting that sunlight, particularly UV radiation, is more a sink than a source for TEP. Multiple regression analyses showed the combined positive effect of phytoplankton and heterotrophic prokaryotes (HPs) on TEP distribution in the OAO. In the SWAS, TEPs were positively related to high nucleic acid-containing prokaryotic cells and total phytoplankton biomass, but not to any particular phytoplankton group. Estimated TEP–carbon constituted an important portion of the particulate organic carbon pool in the entire transect (28 %–110 %), generally higher than the phytoplankton and HP carbon shares, which highlights the importance of TEPs in the cycling of organic matter in the ocean.

Climate change vs. socio-economic development: understanding the future South Asian water gap

Abstract. The Indus, Ganges, and Brahmaputra (IGB) river basins provide about 900 million people with water resources used for agricultural, domestic, and industrial purposes. These river basins are marked as “climate change hotspots”, where climate change is expected to affect monsoon dynamics and the amount of meltwater from snow and ice, and thus the amount of water available. Simultaneously, rapid and continuous population growth as well as strong economic development will likely result in a rapid increase in water demand. Since quantification of these future trends is missing, it is rather uncertain how the future South Asian water gap will develop. To this end, we assess the combined impacts of climate change and socio-economic development on the future “blue” water gap in the IGB until the end of the 21st century. We apply a coupled modelling approach consisting of the distributed cryospheric–hydrological model SPHY, which simulates current and future upstream water supply, and the hydrology and crop production model LPJmL, which simulates current and future downstream water supply and demand. We force the coupled models with an ensemble of eight representative downscaled general circulation models (GCMs) that are selected from the RCP4.5 and RCP8.5 scenarios, and a set of land use and socio-economic scenarios that are consistent with the shared socio-economic pathway (SSP) marker scenarios 1 and 3. The simulation outputs are used to analyse changes in the water availability, supply, demand, and gap. The outcomes show an increase in surface water availability towards the end of the 21st century, which can mainly be attributed to increases in monsoon precipitation. However, despite the increase in surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap during the 21st century. This indicates that socio-economic development is the key driver in the evolution of the future South Asian water gap. The transgression of future environmental flows will likely be limited, with sustained environmental flow requirements during the monsoon season and unmet environmental flow requirements during the low-flow season in the Indus and Ganges river basins.

The Photochemical Degradation (PCD) of Nitrobenzene (NB) using UV Light and Fenton Reagent Under Various Conditions

Photochemical degradation contributes to the environmental fate of many pesticides, chemicals, and industrial waste in surface waters. Photochemical degradation (PCD) of Nitrobenzene (NB) has been studied using a UV light source and Fenton reagent under different experimental conditions. The effect of concentration on PCD of NB was monitored and recorded in the range 0.5 x10-4M to 3.0x10-4M. The concentration of H2O2 was performed from 5.0 x10-4M to 2.5 x10-4M and Fe(II) from 1.0 x10-4M to 5.0 x10-4M respectively.In terms of concentration, the absorbance increases with increasing the concentration of the solution of NB, H2O2 and Fe(II). The initial rate of PCD was recorded at fixed pH 2.42 of solution. Two optimums for pH were found for PCD of Nitrobenzene ranging from pH 2.42 to 4.20. The intermediates formed during PCD of NB were identified, by which a mechanism was then suggested that PCD is actually found to follow pseudo first order kinetics.

Water sampling techniques for continous monitoring of pesticides in water

Good ecological and chemical status of water represents the most important aim of the Water Framework Directive 2000/60/EC, which implies respect of water quality standards at the level of entire river basin (2008/105/EC and 2013/39/EC). This especially refers to the control of pesticide residues in surface waters. In order to achieve the set goals, a continuous monitoring program that should provide a comprehensive and interrelated overview of water status should be implemented. However, it demands the use of appropriate analysis techniques. Until now, the procedure for sampling and quantification of residual pesticide quantities in aquatic environment was based on the use of traditional sampling techniques that imply periodical collecting of individual samples. However, this type of sampling provides only a snapshot of the situation in regard to the presence of pollutants in water. As an alternative, the technique of passive sampling of pollutants in water, including pesticides has been introduced. Different samplers are available for pesticide sampling in surface water, depending on compounds. The technique itself is based on keeping a device in water over a longer period of time which varies from several days to several weeks, depending on the kind of compound. In this manner, the average concentrations of pollutants dissolved in water during a time period (time-weighted average concentrations, TWA) are obtained, which enables monitoring of trends in areal and seasonal variations. The use of these techniques also leads to an increase in sensitivity of analytical methods, considering that pre-concentration of analytes takes place within the sorption medium. However, the use of these techniques for determination of pesticide concentrations in real water environments requires calibration studies for the estimation of sampling rates (Rs). Rs is a volume of water per time, calculated as the product of overall mass transfer coefficient and area of the receiving phase exposed to the external environment, and it is substance specific.

Interactions among members of the microbial loop in an estuary dominated by microzooplankton grazing

ABSTRACT: Modified dilution experiments were employed to characterize the microbial loop insurface waters at sites along an estuarine−offshore gradient in the northern Gulf of Mexico. Estu-arine surface waters were more variable than those offshore due to the strong influence of riverdischarge. Phytoplankton (chlorophyll a) and prokaryotes were both significantly higher in theestuary than offshore, but virus and heterotrophic nanoflagellate abundances did not differ acrossthe gradient. Grazing was detected in the majority of experiments, while viral lysis was onlydetected in 24% of phytoplankton and 12% of prokaryote experiments. Growth and grazing ratesfor both phytoplankton and prokaryotes were tightly coupled, except for locations within strongenvironmental transition zones. A large, but variable, percentage of phytoplankton (83 ± 149%)and prokaryote (70 ± 64%) production was grazed by microzooplankton across the estuary. Whilemicrozooplankton grazing is responsible for the removal of the majority of microbial production,thus supporting productivity of higher trophic levels, the role of viral lysis remains unclear.KEY WORDS: Grazing · Viral lysis · Estuaries · Nutrient limitation · Microbial loop

Heat transfer on grooved high density poly ethylene tube for surface water source heat pump

High density polyethylene (HDPE) tube has been successfully utilized in surface water source heat pump (SWSHP) system as a surface water heat exchanger (SWHE). Since the heat transfer coefficient (U value) of the HDPE tube directly affects performance and energy efficiency of SWSHP, this research aims to increase U value of HDPE tube by grooving external surface of conventional 32A HDPE tube to reducing cross sectional volume. The final shape of grooved HDPE tube is similar to that of fin. In order to verify the performance of grooved HDPE tube, the U values of grooved and smooth tube were compared experimentally. According to the results, U value of grooved tube showed approximately 21.5% increase with natural convection and 23.5% with forced convection system than U values obtained from smooth tube. The reason for such increase in U value was found to be the reduction in cross sectional volume of the HDPE tube.

Regulating Water Quality: Current Legislation, Future Impacts: Introduction to the Colloquium

Additional index words. Chesapeake Bay, Clean Water Act, floating treatment wetlands, nitrogen, numeric nutrient criteria, nursery cropproduction, pesticides, phosphorus, sediment, sub-surface flow wetlands, surface-flow wetlands, water samplingIncreased rates of nutrient enrichment insurface water bodies have led to detrimentalimpacts to aquatic ecosystems; these impactsinclude algal blooms, fish kills, and deadzones. Environmental groups and concernedcitizens have begun to demand greater pro-tection and restoration of our natural water-ways,becausebothhumanandecologicalusesare currently impaired as a result of increasedrates of nutrient and sediment loading. Manypolicieshavebeenenactedinregionsthrough-out the United States to reduce nutrient load-ing with the ultimate goal of improvingsurfacewaterqualityandrestoringecologicalfunction (e.g., fisheries, native plant communi-ties) [U.S. Environmental Protection Agency(EPA), 2010a, 2010b, 2012].Concern for aquatic ecosystem health hasled to federal enforcement of the EPA CleanWater Action Plan in two current cases,which include: the numeric nutrient criterionimposed on surface waters in Florida and theChesapeake Bay consent decree where totalmaximumdailyloadswereimposedtoreducenutrient loading into surface waters (U.S.EPA, 1998, 2010a, 2010b). These nutrientloadreduction mandatesimpact allsectors ofsociety, including industrial, urban, and ag-ricultural water users, because wastewaterfrom all of these land use types contributeto the overall load of nutrients within anecosystem, regardless of whether the waste-waterisconsideredtobefromapointsourceor a nonpoint source.Manyhorticulturalcropproducersarebeingimpacted in Florida and the Chesapeake Baywatershed (Delaware, the District of Colum-bia, Maryland, New York, Pennsylvania,Virginia, and West Virginia); these statesare currently implementing changes in prac-tice or evaluating potential changes to mod-erate the amount of nitrogen (N), phosphorus(P), and sediment in wastewater leaving farms.Additional nutrient regulations will likely im-pact additional horticultural crop producersthroughout the United States over the nextdecade, because degrading surface waterquality is a national issue. Without an ade-quate understanding of the complex issuessurrounding agricultural water use and reuse,scientists, policymakers, and extension spe-cialists alike will not be able to address themultifaceted management problems that hor-ticultural crop producers are likely to face inthe coming years. In light of these complexissuesandtheneedforopendiscourseamongthese groups, the American Society for Hor-ticultural Science Nursery Crops workinggroup convened a colloquium entitled ‘‘Reg-ulating Water Quality: Current Legislation,FutureImpacts,’’cosponsoredwiththeWaterUtilization and Management, Waste Utiliza-tioninHorticulture,andFloricultureworkinggroups to educate attendees regarding 1) thecurrent state of nutrient-based legislation; 2)the impact of Florida Department of Envi-ronmental Quality imposed numeric nutrientcriterion on growers’ changing practices inFlorida; and 3) the remediation technologiesavailable for growers’ compliance with man-dated nutrient and sediment limits for runofffrom production areas.THE COLLOQUIUMThe three articles in this series discussthe current regulatory climate, the impactof regulations on managing water quality,and the remediation technologies currentlyavailable to cleanse wastewater of nutrientandsedimentcontaminants.Fourcolloquiumspeakers, Steve Beeman (Beeman’s Nursery),Pete Spyke (Arapaho Citrus Management,Inc.), Aliso Coe (EarthJustice), and Dr. P.ChristopherWilson(UniversityofFlorida),declined the opportunity to submit articles.An overview of the presentations is discussedin the order presented during the colloquium.A BRIEF HISTORY OF REGULATORYACTIONSMajsztrik and Lea-Cox (2013) presenta brief history of the legislative actions takento restore the Chesapeake Bay that culminatedwith introduction of federally mandated totalmaximum daily load limits in 2010 (U.S.EPA, 2010a) and current efforts to accelerateimplementation of best management practices.The need for increased communication amongregulatory agencies, policymakers, modelers,and stakeholders is discussed with regard tomanaging and accurately accounting forchanges in nonpoint source contributions tothe watershed. This article specifically em-phasizes efforts to accurately characterizecurrent nursery and greenhouse inputs, thepotential affect of altering production prac-tices, and implementing best managementpractices to reductions of nutrient and sed-iment contaminants in the Chesapeake Bay.The value and longevity of nutrient tradingcredits are discussed along with pitfalls andbenefits for growers.AlisaCoe,anAssociateAttorneywiththeTallahasseeOfficeofEarthjustice,anon-profit,public interest law organization, discussed therole of political activism in impacting policychange.In2008,acoalitionofenvironmentalorganizationsrepresentedbyEarthjusticefileda lawsuit against the U.S. EPA for failing tocomply with its nondiscretionary duty to setnumeric nutrient criterion for Florida as man-dated by the 1972 Clean Water Act and the1998 Clean Water Action Plan (Douglas,2012; Stanton and Taylor, 2012). The depthof problems created by unmitigated nutrientrunoff into surface waters included humanhealth, ecological sustainability, and economicconcerns. Human health concerns were relatedto drinking water contamination and dermal orinhalation contact with algae that secrete/excretetoxins.Environmentalandecosystemhealth concerns were related to habitat lossand fish kills from low dissolved oxygen.Economicconcernswererelatedtodecreasedproperty values and declining tourism insome regions of Florida where waterwaysare detrimentally impacted by algal blooms.These issues were the motivating factors forthe ‘‘Clean Water Act Citizen Suit.’’The foundational argument for the CleanWater Act Citizen Suit was that the FloridaDepartmentofEnvironmentalProtection(FLDEP) had not developed numeric limits forsewage, fertilizer, and manure pollution 9years after the Clean Water Action Plan wasenacted. Thus, the U.S. EPA should enforcenutrient criterion in water bodies in Floridarather than the FL DEP. In January 2009, theEPA made a determination that Florida’snarrative standards were ineffective and nu-meric nutrient criteria were, in fact, neededfor Florida’s water bodies. In Aug. 2009, thelitigation was settled with a consent decreerequiringdevelopmentofspecificor‘‘numeric’’

Diagnóstico espaço-temporal da ocorrência de herbicidas nas águas superficiais e sedimentos do Rio Corumbataí e principais afluentes

SPATIAL-TEMPORAL DIAGNOSTIC OF HERBICIDE OCCURRENCE IN SURFACE WATERS AND SEDIMENTS OF CORUMBATAI RIVER AND MAIN AFFLUENTS. Residues of herbicides from sugarcane were monitored in waters and sediments of Corumbatai River and tributaries. Ametryne, atrazine, simazine, hexazinone, glyphosate, and clomazone were detected in water samples, with negligible levels of ametryne and glyphosate in sediment samples. The area of recharge of the Guarani aquifer presented the highest triazine and clomazone levels. The triazines were detected at higher levels, with atrazine above Brazil's potability and quality standards. Total herbicide levels at some sampling points were 13 times higher than the European Community potability limit. There is no Brazilian standard for ametryne, although the risk is larger due to ametryne's higher toxicity for the aquatic biota.

UV EXPERIENCE FOR INACTIVATING CRYPTOSPORIDIUM IN SURFACE WATER PLANTS

UV EXPERIENCE FOR INACTIVATING CRYPTOSPORIDIUM IN SURFACE WATER PLANTSThe disinfection of pathogenic microbes in drinking water has been largely successful over the last century due to the use of chlorination. However, research conducted in the 1970's revealed that by-products formed during the chlorination process are potentially carcinogenic and that there is a direct correlation between the concentration of chlorination by-products and the probability of certain...Author(s)Daniel BrooksGary Van StoneWayne LemSourceProceedings of the Water Environment FederationSubjectSession 5 -- Drinking Water 1Document typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2001ISSN1938-6478SICI1938-6478(20010101)2001:6L.331;1-DOI10.2175/193864701784291848Volume / Issue2001 / 6Content sourceWEFTEC Latin AmericaFirst / last page(s)331 - 344Copyright2001Word count104

Eutrophication processes in a shallow, macrophyte dominated lake — alkaline phosphatase activity in Lake Łuknajno (Poland)

Alkaline phosphatase activity (APA) of unfiltered andfractionated (algae, bacteria, dissolved) surface watersamples was measured using a spectrophotometric method in LakeŁuknajno from May to September 1993. The total enzymaticactivity varied between 0.44–2.35 µmol l−1h−1.Algae were major producers of alkaline phosphatase activity insurface water of the lake from May to August, and theiractivity constituted on the average 67% of the total APAactivity in the water. APA activity in bacterial size fractionwas low and constituted 9.6% (mean) of the total activity.The activities of free (dissolved in water) enzymes wererelative high during the time of study. This study show thathydrolysis of organic phosphomonoesters by alkalinephosphatase was negligible in the recycling of phosphorus inŁuknajno Lake.

Tolerance levels of redbreast tilapia, Tilapia rendalli (Boulenger, 1896) to natural suspended silt

Tilapia rendalli was exposed to various siltconcentrationsfor different exposure periods to determine LC50 andsublethalconcentration ranges. The extent of damaging effects, if any,ofsuspended silt on the exposed fish, were investigated by meansofscanning electron microscopy. The LC50 values rangedbetween21 to 24 g l™1 and 42–48 g l™1 for juveniles andadultsrespectively. The silt concentrations tolerated by the testfisheswere above those found in most natural waters. The resultstherefore support the hypothesis that suspended silt is lethaltofish at concentrations higher than those naturally observed insurface water. The observed mortalities can be attributed tothecombined physical effects of high silt concentrations andassociated reduction in dissolved oxygen levels. To preventfishmortalities and other impacts on biota, anthropogenicactivitiesthat affect the natural variation in suspended siltconcentrationsin surface water should be carefully monitored and, wherepossible,be restricted.