WorldWideScience

Sample records for professor aquatic plants

  1. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  2. Aquatic Plants and their Control.

    Science.gov (United States)

    Michigan State Dept. of Natural Resources, Lansing.

    Aquatic plants can be divided into two types: algae and macrophytes. The goal of aquatic plant management is to maintain a proper balance of plants within a lake and still retain the lake's recreational and economic importance. Aquatic plant management programs have two phases: long-term management (nutrient control), and short-term management…

  3. Introduced aquatic plants and algae

    Science.gov (United States)

    Non-native aquatic plants such as waterhyacinth and hydrilla severely impair the uses of aquatic resources including recreational faculties (lakes, reservoirs, rivers) as well as timely delivery of irrigation water for agriculture. Costs associated with impacts and management of all types of aquatic...

  4. Aquatic Plant Control Research Program

    National Research Council Canada - National Science Library

    Cofrancesco, Alfred

    1998-01-01

    .... This search for natural plant enemies (insects and fungal pathogens) has led researchers to the native ranges of noxious aquatic plants, located throughout the continents of Africa, Asia, Europe, and Australia...

  5. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  6. Macrophytes: Ecology of aquatic plants

    NARCIS (Netherlands)

    Bornette, G.; Puijalon, S.

    2009-01-01

    Aquatic plants contribute to maintaining key functions and related biodiversity in freshwater ecosystems, and to provide the needs of human societies. The way the ecological niches of macrophytes are determined by abiotic filters and biotic ones is considered. A simple, broadly applicable model of

  7. Bioassay of Plant Growth Regulator Activity on Aquatic Plants

    Science.gov (United States)

    1990-07-01

    I COPY AQUATIC PLANT CONTROL RESEARCH PROGRAM .q TECHNICAL REPORT A-90-7 >AD-A226 125 BIOASSAY OF PLANT GROWTH REGULATOR ACTIVITY ON AQUATIC PLANTS... Plant Growth Regulator Activity on Aquatic Plants 12. PERSONAL AUTHOR(S) Lembi, Carole A.; Netherland, Michael D. 13a. TYPE OF REPORT 13b. TIME COVERED 14...OF THIS PAGE 18. SUBJECT TERMS (Continued). Aquatic plants Hydrilla Bensulfuron methyl Paclobutrazol Bioassay Plant growth regulator Eurasian

  8. Aquatic plant control research

    Energy Technology Data Exchange (ETDEWEB)

    Pryfogle, P.A.; Rinehart, B.N. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, E.G. [Pacific Gas & Electric Company, San Francisco, CA (United States). Hydro Generation Engineering

    1997-05-01

    The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

  9. Aquatic plants for removal of mevinphos from the aquatic environment

    Science.gov (United States)

    Wolverton, B. C.

    1975-01-01

    Fragrant waterlily (Nymphaea odorata, Ait.), joint-grass (Paspalum distichum L.), and rush (Juncus repens, Michx.) were used to evaluate the effectiveness of vascular aquatic plants in removing the insecticide mevinphos (dimethyl-1-carbomethoxy-1propen-2-yl phosphate) from waters contaminated with this chemical. The emersed aquatic plants fragrant waterlily and joint-grass removed 87 and 93 ppm of mevinphos from water test systems in less than 2 weeks without apparent damage to the plants; whereas rush, a submersed plant, removed less insecticide than the water-soil controls. Water-soil control still contained toxic levels of this insecticide, as demonstrated by fish bioassay studies, after 35 days.

  10. Control of Fish and Aquatic Plants.

    Science.gov (United States)

    Hesser, R. B.; And Others

    This agriculture extension service publication from Pennsylvania State University is a handbook for the water body manager. The bulk of the contents deals with aquatic plant control. The different types of aquatic plants, their reproduction and growth, and their role in the ecology of the water body are introduced in this main section. Also, the…

  11. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  12. Aquatic Plant Control Research Program: The Rhizosphere Microbiology of Rooted Aquatic Plants.

    Science.gov (United States)

    1988-04-01

    540-553. Bagyaraj, C. J., A. Manjunath, and R. B. Patil. 1979. Occurrence of vesicular- arbuscular mycorrhizas in some tropical aquatic plants...39-45. Chaubal, R., G. D. Charma, and R. R. Mishra. 1982. Vesicular- arbuscular mycorrhiza in subtropical aquatic and marshy plant communities...11A:29-35. Clayton, J. S. and D. J. Bagyaraj. 1984. Vesicular- arbuscular mycorrhizas in submerged aquatic plants of New Zealand. Aquatic Botany. 19:251

  13. Emergent aquatic plants: biological and economic perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Kresovich, S.; Wagner, C.K.; Scantland, D.A.; Lawhon, W.T.

    1981-01-01

    One of the most productive, but least exploited, biomass resources is the group classified as the emergent aquatic plants. Information is presented concerning the biological and economic factors that must be considered if emergent aquatic plants are to become viable feedstocks for multipurpose systems. The feedstock purposes highlighted include fuel and/or chemical production and the species identified as potential candidates for production in biomass systems include Arundo donax, Cyperus papyrus, Phragmites communis, Saccharum spontaneum, Spartina alterniflora, and Typha latifolla. If these species are to be viable candidates in biomass systems, a number of research areas must be investigated further. Issues such as the development of base-line yield data for managed systems, mechanization and harvesting conceptualization, genetic (crop) improvement, identification of secondary plant products, and economic considerations require refinement. However, the potential pay-off for developing emergent aquatic systems will be significant if successful. 19 references.

  14. Plants in aquatic ecosystems: current trends and future directions

    NARCIS (Netherlands)

    O’Hare, Matthew T.; Aguiar, Francisca C.; Asaeda, Takashi; Bakker, Elisabeth S.; Chambers, Patricia A.; Clayton, John S.; Elger, Arnaud; Ferreira, Teresa M.; Gross, Elisabeth M.; Gunn, Iain D.M.; Gurnell, Angela M.; Hellsten, Seppo; Hofstra, Deborah E.; Li, Wei; Mohr, Silvia; Puijalon, Sara; Szoszkiewicz, Krzysztof; Willby, Nigel J.; Wood, Kevin A.

    2017-01-01

    Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International

  15. Crassulacean acid metabolism in submerged aquatic plants

    Science.gov (United States)

    Keeley, Jon E.; Sybesme, C.

    1984-01-01

    CO2-fixation in the dark is known to occur in various organs of many plants. However, only in species possessing crassulacean acid metabolism (CAM) does dark CO2-fixation contribute substantially to the carbon economy of the plant. Until very recently CAM was known only from terrestrial species, largely drought adapted succulents. The discovery of CAM in the submerged aquatic fern ally Isoetes howellii (Isoetaceae)(Keeley 1981) adds a new dimension to our understanding of crassulacean acid metabolism. In this paper I will summarize 1) the evidence of CAM in Isoetes howellii, 2) the data on the distribution of CAM in aquatic species, and 3) the work to date on the functional significance of CAM in aquatic species.

  16. CAM Photosynthesis in Submerged Aquatic Plants

    Science.gov (United States)

    Keeley, J.E.

    1998-01-01

    Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism selected in response to aridity in terrestrial habitats, and, in aquatic environments, to ambient limitations of carbon. Evidence is reviewed for its presence in five genera of aquatic vascular plants, including Isoe??tes, Sagittaria, Vallisneria, Crassula, and Littorella. Initially, aquatic CAM was considered by some to be an oxymoron, but some aquatic species have been studied in sufficient detail to say definitively that they possess CAM photosynthesis. CO2-concentrating mechanisms in photosynthetic organs require a barrier to leakage; e.g., terrestrial C4 plants have suberized bundle sheath cells and terrestrial CAM plants high stomatal resistance. In aquatic CAM plants the primary barrier to CO2 leakage is the extremely high diffusional resistance of water. This, coupled with the sink provided by extensive intercellular gas space, generates daytime CO2(Pi) comparable to terrestrial CAM plants. CAM contributes to the carbon budget by both net carbon gain and carbon recycling, and the magnitude of each is environmentally influenced. Aquatic CAM plants inhabit sites where photosynthesis is potentially limited by carbon. Many occupy moderately fertile shallow temporary pools that experience extreme diel fluctuations in carbon availability. CAM plants are able to take advantage of elevated nighttime CO2 levels in these habitats. This gives them a competitive advantage over non-CAM species that are carbon starved during the day and an advantage over species that expend energy in membrane transport of bicarbonate. Some aquatic CAM plants are distributed in highly infertile lakes, where extreme carbon limitation and light are important selective factors. Compilation of reports on diel changes in titratable acidity and malate show 69 out of 180 species have significant overnight accumulation, although evidence is presented discounting CAM in some. It is concluded that similar proportions of the aquatic

  17. Aquatic Plant Genomics: Advances, Applications, and Prospects

    Science.gov (United States)

    Li, Gaojie; Yang, Jingjing

    2017-01-01

    Genomics is a discipline in genetics that studies the genome composition of organisms and the precise structure of genes and their expression and regulation. Genomics research has resolved many problems where other biological methods have failed. Here, we summarize advances in aquatic plant genomics with a focus on molecular markers, the genes related to photosynthesis and stress tolerance, comparative study of genomes and genome/transcriptome sequencing technology. PMID:28900619

  18. Decomposition of aquatic plants in lakes

    Energy Technology Data Exchange (ETDEWEB)

    Godshalk, G.L.

    1977-01-01

    This study was carried out to systematically determine the effects of temperature and oxygen concentration, two environmental parameters crucial to lake metabolism in general, on decomposition of five species of aquatic vascular plants of three growth forms in a Michigan lake. Samples of dried plant material were decomposed in flasks in the laboratory under three different oxygen regimes, aerobic-to-anaerobic, strict anaerobic, and aerated, each at 10/sup 0/C and 25/sup 0/C. In addition, in situ decomposition of the same species was monitored using the litter bag technique under four conditions.

  19. Urban Water-Quality Management. Purchasing Aquatic Plants

    OpenAIRE

    French, Sue (Sue C.); Fox, Laurie; Andruczyk, Mike; Gilland, Traci; Swanson, Lynette

    2009-01-01

    Aquatic plants are essential for a healthy and environmentally balanced water garden. Whether you are installing a new water feature or renovating an existing one, proper plant selection is critical. The following steps will help you select and purchase aquatic plants.

  20. Methane emissions to the atmosphere through aquatic plants

    Science.gov (United States)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1985-01-01

    The movement of methane (CH4) from anaerobic sediments through the leaves, stems, and flowers of aquatic plants and into the atmosphere was found to provide a significant pathway for the emission of CH4 from the aquatic substrates of flooded wetlands. Methane concentrations well above the surrounding ambient air levels were found in the mesophyll of 16 varies of aquatic plants and are attributed to transpiration, diffusion, and pressure-induced flow of gaseous CH4 from the roots when they are embedded in CH4-saturated anaerobic sediments. Methane emissions from the emergent parts of aquatic plants were measured using floating chamber techniques and by enclosing the plants in polyethylene bags of known volume. Concentration changes were monitored in the trapped air using syringes and gas chromatographic techniques. Vertical profiles of dissolved CH4 in sediment pore water surrounding the aquatic plants' rhizomes were obtained using an interstitial sampling technique. Methane emissions from the aquatic plants studied varied from 14.8 mg CH4/d to levels too low to be detectable. Rooted and unrooted freshwater aquatic plants were studied as well as saltwater and brackish water plants. Included in the experiment is detailed set of measurements on CH4 emissions from the common cattail (Typha latifolia). This paper illustrates that aquatic plants play an important gas exchange role in the C cycle between wetlands and the atmosphere.

  1. Public lakes, private lakeshore: modeling protection of native aquatic plants.

    Science.gov (United States)

    Schroeder, Susan A; Fulton, David C

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  2. Public lakes, private lakeshore: Modeling protection of native aquatic plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-01-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221–279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners’ behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  3. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  4. Aquatic Plant Control Research Program. Volume A-00-1

    National Research Council Canada - National Science Library

    Kirk, James

    2000-01-01

    ... at the Waterways Experiment Station. It is principally intended to be a forum whereby information pertaining to and resulting from the Corps of Engineers' nationwide Aquatic Plant Control Research Program (APCRP...

  5. Master plan: Guntersville Reservoir Aquatic Plant Management. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    In 1989, Congress provided funding to start a five-year comprehensive project to manage aquatic plants in Guntersville Reservoir, to be jointly implemented by the US Army Corps of Engineers (Corps) and Tennessee Valley Authority (TVA). TVA serves as the overall project coordinator and is the lead agency for this project. Known as the Joint Agency Guntersville Project (JAGP), the project will test and demonstrate innovative management technologies, and incorporate the most effective technologies into a comprehensive aquatic plant management plan for Guntersville Reservoir. The JAGP is intended to serve as a National Demonstration Project for aquatic plant management. As part of this JAGP, the Master Plan for Aquatic Plant Management for the Guntersville Reservoir Project, Alabama-Tennessee is authorized by Corps Contract Number DACW62-90-C-0067.

  6. Biomarkers in aquatic plants: selection and utility.

    Science.gov (United States)

    Brain, Richard A; Cedergreen, Nina

    2009-01-01

    This review emphasizes the predictive ability, sensitivity and specificity of aquatic plant biomarkers as biomonitoring agents of exposure and effect. Biomarkers of exposure are those that provide functional measures of exposure that are characterized at a sub-organism level. Biomarkers of effect require causal linkages between the biomarker and effects, measured at higher levels of biological organization. With the exception of pathway specific metabolites, the biomarkers assessed in this review show variable sensitivity and predictive ability that is often confounded by variations in growth conditions, rendering them unsuitable as stand alone indicators of environmental stress. The use of gene expression for detecting pollution has been, and remains immature; this immaturity derives from inadequate knowledge on predictive ability, sensitivity and specificity. Moreover, the ability to the detect mode of action of unknown toxicants using gene expression is not as clear-cut as initially hypothesized. The principal patterns in gene expression is not as clear-cut as initially hypothesized. The principal patterns in gene expression are generally derived from stress induced genes, rather than on ones that respond to substances with known modes of action (Baerson et al. 2005). Future developments in multivariate statistics and chemometric methods that enhance pattern analyses in ways that could produce a "fingerprint", may improve methods for discovering modes of action of unknown toxicants. Pathway specific metabolites are unambiguous, sensitive, correlate well to growth effects, and are relatively unaffected by growth conditions. These traits make them excellent biomarkers under both field and laboratory conditions. Changes in metabolites precede visible growth effects; therefore, measuring changes in metabolite concentrations (Harring et al. 1998; Shaner et al. 2005). The metabolic phase I enzymes (primarily associated with P-450 activity) are non-specific biomarkers

  7. Aquatic plant surface as a niche for methanotrophs

    Science.gov (United States)

    Yoshida, Naoko; Iguchi, Hiroyuki; Yurimoto, Hiroya; Murakami, Akio; Sakai, Yasuyoshi

    2014-01-01

    This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7–37 μmol·h−1·g−1 dry weight, which was ca 5.7–370-fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 105–107 copies·g−1 dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86–89%) to Methylocaldum gracile. PMID:24550901

  8. Aquatic plant surface as a niche for methanotrophs

    Directory of Open Access Journals (Sweden)

    Naoko eYoshida

    2014-02-01

    Full Text Available This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7 – 37 μmol⋅h-1⋅g-1 dry weight, which was ca 5.7-370 fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 105 to 107 copies⋅g-1 dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86-89% to Methylocaldum gracile.

  9. Aquatic and wetland vascular plants of the northern Great Plains

    Science.gov (United States)

    Gary E. Larson

    1993-01-01

    A taxonomic treatment of aquatic and wetland vascular plants has been developed as a tool for identifying over 500 plant species inhabiting wetlands of the northern Great Plains region. The treatment provides dichotomous keys and botanical descriptions to facilitate identification of all included taxa. Illustrations are also provided for selected species. Geographical...

  10. Aquatic plants as potential sources of antimicrobial compounds ...

    African Journals Online (AJOL)

    Resistance of pathogens to common veterinary antibiotics hampers mastitis treatment and motivates the discovery of new antimicrobials. In this study, extracts from two aquatic plants, Salvinia auriculata and Hydrocleys nymphoides, were assayed against bovine mastitis pathogens. Selected parts of plants were extracted ...

  11. Hydrothermal liquefaction of aquatic plants to bio-oils

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, D.; Zhang, L.; Zhang, S.; Fu, H.; Chen, J. [Fudan Univ., Shanghai (China). Dept. of Environmental Science and Engineering

    2010-07-01

    This study investigated the feasibility of producing bio-oils from aquatic plants by hydrothermal liquefaction using 2 typical aquatic plants as feedstocks, notably Enteromorpha prolifera and water hyacinth which are typical aquatic plants found in seawater and freshwater. Bio-oil production from these 2 feedstocks was studied in a batch reactor at controlled temperatures under an initial partial pressure of 2.0 MPa N2. The effects of temperature and reaction time on the liquefaction products yields were also studied. GC-MS and elemental analysis were carried out to analyze the composition of bio-oils. The bio-oil produced from Enteromorpha prolifera contained mainly fatty acids, esters and quite a few heterocyclic compounds. Phenols and their derivatives were found to be the main compounds in bio-oils produced from water hyacinth. An elemental analysis revealed that bio-oils produced from the 2 aquatic plants have higher energy density. It was concluded that the use of aquatic plants as feedstock for liquid fuel can contribute to environmental protection and sustainable energy development by reducing greenhouse gas emissions associated with the burning of fossil fuels. 9 refs., 3 tabs.

  12. Herbivore regulation of plant abundance in aquatic ecosystems.

    Science.gov (United States)

    Wood, Kevin A; O'Hare, Matthew T; McDonald, Claire; Searle, Kate R; Daunt, Francis; Stillman, Richard A

    2017-05-01

    Herbivory is a fundamental process that controls primary producer abundance and regulates energy and nutrient flows to higher trophic levels. Despite the recent proliferation of small-scale studies on herbivore effects on aquatic plants, there remains limited understanding of the factors that control consumer regulation of vascular plants in aquatic ecosystems. Our current knowledge of the regulation of primary producers has hindered efforts to understand the structure and functioning of aquatic ecosystems, and to manage such ecosystems effectively. We conducted a global meta-analysis of the outcomes of plant-herbivore interactions using a data set comprised of 326 values from 163 studies, in order to test two mechanistic hypotheses: first, that greater negative changes in plant abundance would be associated with higher herbivore biomass densities; second, that the magnitude of changes in plant abundance would vary with herbivore taxonomic identity. We found evidence that plant abundance declined with increased herbivore density, with plants eliminated at high densities. Significant between-taxa differences in impact were detected, with insects associated with smaller reductions in plant abundance than all other taxa. Similarly, birds caused smaller reductions in plant abundance than echinoderms, fish, or molluscs. Furthermore, larger reductions in plant abundance were detected for fish relative to crustaceans. We found a positive relationship between herbivore species richness and change in plant abundance, with the strongest reductions in plant abundance reported for low herbivore species richness, suggesting that greater herbivore diversity may protect against large reductions in plant abundance. Finally, we found that herbivore-plant nativeness was a key factor affecting the magnitude of herbivore impacts on plant abundance across a wide range of species assemblages. Assemblages comprised of invasive herbivores and native plant assemblages were associated with

  13. Biological Fenton's oxidation of pentachlorophenol by aquatic plants.

    Science.gov (United States)

    Reis, Andre Rodrigues dos; Kyuma, Yukako; Sakakibara, Yutaka

    2013-12-01

    This study proposes a new treatment method to decompose persistent chemicals such as pentachlorophenol (PCP) in water, utilizing hydrogen peroxide present in aquatic plants to proceed the biological Fenton reaction. PCP was not effectively removed by aquatic plants. However, by adding 2.8 mM of Fe(2+), there was a rapid removal of PCP while at the same time consumption of endogenous hydrogen peroxide occurred. It was observed the increase of chloride ions formation in water-confirming the complete degradation of PCP. These results demonstrated that PCP was oxidized through a biological Fenton reaction, and hydrogen peroxide in aquatic plants was a key endogenous substance in treatment of refractory toxic pollutants.

  14. Late cretaceous aquatic plant world in Patagonia, Argentina.

    Science.gov (United States)

    Cúneo, N Rubén; Gandolfo, María A; Zamaloa, María C; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  15. Late cretaceous aquatic plant world in Patagonia, Argentina.

    Directory of Open Access Journals (Sweden)

    N Rubén Cúneo

    Full Text Available In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla and a monocot (Araceae. Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae. Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form and the eudicot angiosperm Nelumbo (Nelumbonaceae are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae, ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  16. Mercury uptake and accumulation by four species of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

    2007-01-15

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

  17. A co-beneficial system using aquatic plants: bioethanol production from free-floating aquatic plants used for water purification.

    Science.gov (United States)

    Soda, S; Mishima, D; Inoue, D; Ike, M

    2013-01-01

    A co-beneficial system using constructed wetlands (CWs) planted with aquatic plants is proposed for bioethanol production and nutrient removal from wastewater. The potential for bioethanol production from aquatic plant biomass was experimentally evaluated. Water hyacinth and water lettuce were selected because of their high growth rates and easy harvestability attributable to their free-floating vegetation form. The alkaline/oxidative pretreatment was selected for improving enzymatic hydrolysis of the aquatic plants. Ethanol was produced with yields of 0.14-0.17 g-ethanol/ g-biomass in a simultaneous saccharification and fermentation mode using a recombinant Escherichia coli strain or a typical yeast strain Saccharomyces cerevisiae. Subsequently, the combined benefits of the CWs planted with the aquatic plants for bioethanol production and nutrient removal were theoretically estimated. For treating domestic wastewater at 1,100 m(3)/d, it was inferred that the anoxic-oxic activated sludge process consumes energy at 3,200 MJ/d, whereas the conventional activated sludge process followed by the CW consumes only 1,800 MJ/d with ethanol production at 115 MJ/d.

  18. Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize

    DEFF Research Database (Denmark)

    Rich, Sarah Meghan; Ludwig, Martha; Pedersen, Ole

    2011-01-01

    • Many wetland plants produce aquatic adventitious roots from submerged stems. Aquatic roots can form chloroplasts, potentially producing endogenous carbon and oxygen. Here, aquatic root photosynthesis was evaluated in the wetland plant Meionectes brownii, which grows extensive stem-borne aquatic...... m(-3) dissolved CO(2), aquatic roots fix carbon at 0.016 µmol CO(2) g(-1) DM s(-1). Illuminated aquatic roots do not rely on exogenous inputs of O(2). • The photosynthetic ability of aquatic roots presumably offers an advantage to submerged M. brownii as aquatic roots, unlike sediment roots, need...... little O(2) and carbohydrate inputs from the shoot when illuminated....

  19. Hydrothermal processing of biomass from invasive aquatic plants

    Science.gov (United States)

    W. James Catallo; Todd F. Shupe; Thomas L. Eberhardt

    2008-01-01

    The purpose of this study was to examine the hydrothermal (HT) treatment of three invasive aquatic plants (i.e., Lemna sp., Hydrilla sp., and Eichhornia sp.) with respect to the generation of semi-volatile hydrocarbon product mixtures and biomass volume reduction. Identical HT treatments yielded similar semi-...

  20. Characterization of three invading aquatic plants in Burkina Faso ...

    African Journals Online (AJOL)

    ... pinnata and C. demersum and 4 units for T. australis. The fonio and the maize biomass production were not significantly different for substrates. The maize yield benefit was highest for C. demersum. The three aquatic invading plants represent a high potential for crop production in the Sahel. However, the long term effects ...

  1. Aquatic Plants and Wastewater Treatment (an Overview)

    Science.gov (United States)

    Wolverton, B. C.

    1986-01-01

    The technology for using water hyacinth to upgrade domestic sewage effluent from lagoons and other wastewater treatment facilities to secondary and advanced secondary standards has been sufficiently developed to be used where the climate is warm year round. The technology of using emergent plants such as bulrush combined with duckweed is also sufficiently developed to make this a viable wastewater treatment alternative. This system is suited for both temperate and semi-tropical areas found throughout most of the U.S. The newest technology in artificial marsh wastewater treatment involves the use of emergent plant roots in conjunction with high surface area rock filters. Smaller land areas are required for these systems because of the increased concentration of microorganisms associated with the rock and plant root surfaces. Approximately 75 percent less land area is required for the plant-rock system than is required for a strict artificial wetland to achieve the same level of treatment.

  2. Long-term effects of heavy metals on aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    van der Werff, M.; Pruyt, M.J.

    1982-01-01

    In long-term experiments lasting up to 73 days the effect of rather low levels of zinc, copper, lead and cadmium on the growth and metal uptake was studied by investigating four aquatic plant species: Elodea nuttallii, Callitriche plataycarpa, Spirodela polyrhiza and Lemma gibba. Except Elodea, which was already very sensitive to 5 ..mu..mol Cu 1/sup -1/, no differentiation in growth or mortality could be detected depending on species or elements. There was a clear differentiation between the uptake levels of the heavy metals with regard to the plant species, resulting in a higher heavy metal content in the submerged species in comparison to the floating ones. For zinc, lead and cadmium, an equal ratio was detected between the concentration in the medium and in the plant tissue independent of the plant species. The involvement of roots in element absorption by aquatic plants and the possibility of using aquatic plants as indicators of heavy metal pollution in Dutch waters are discussed.

  3. Toxicity and removal of pesticides by selected aquatic plants.

    Science.gov (United States)

    Olette, Rachel; Couderchet, Michel; Biagianti, Sylvie; Eullaffroy, Philippe

    2008-02-01

    Pesticides are being detected in water bodies on an increasingly frequent basis. The present study focused on the phytoremediation potential of selected aquatic plants to remove phytosanitary products from contaminated water. We investigated the uptake capacity of Lemna minor (L. minor), Elodea canadensis (E. canadensis) and Cabomba aquatica (C. aquatica) on three pesticides: copper sulphate (fungicide), flazasulfuron (herbicide) and dimethomorph (fungicide). Pesticide toxicity was evaluated by exposing plants to five concentrations (0-1 mg L(-1)) in culture media for 7d using chlorophyll fluorescence as a biomarker. The toxicity of the contaminants was the same for all the aquatic plants studied and occurred in this descending order of toxicity: flazasulfuron>copper>dimethomorph. We found that L. minor had the most efficient uptake capacity, followed by E. canadensis and then C. aquatica. The maximum removal rate (microg g(-1)fresh weight d(-1)) of copper, flazasulfuron and dimethomorph was 30, 27 and 11, respectively.

  4. Remediation of feedlot effluents using aquatic plants

    OpenAIRE

    Rizzo, Pedro Federico; Arreghini, Silvana; Serafini, Roberto José María; Bres, Patricia Alina; Crespo, Diana Elvira; Fabrizio de Iorio, Alicia Rosa

    2012-01-01

    Feedlots have increased in several regions of Argentina, particularly in the Pampas. The absence of adequate treatments of the effluents produced in these establishments creates serious problems to the society. Phytoremediation can be defined as inexpensive and environmentally sustainable strategy used to remove pollutants by plants. The aim of this study was to evaluate the remediation potential of two ...

  5. 33 CFR Appendix A to Part 273 - Aquatic Plant Control Program Legislative Authority

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Aquatic Plant Control Program... OF THE ARMY, DEPARTMENT OF DEFENSE AQUATIC PLANT CONTROL Pt. 273, App. A Appendix A to Part 273—Aquatic Plant Control Program Legislative Authority Section 104 of the Rivers and Harbors Act, approved 3...

  6. 33 CFR Appendix B to Part 273 - Information Requirements for Aquatic Plant Control Program Reports

    Science.gov (United States)

    2010-07-01

    ... Aquatic Plant Control Program Reports B Appendix B to Part 273 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE AQUATIC PLANT CONTROL Pt. 273, App. B Appendix B to Part 273—Information Requirements for Aquatic Plant Control Program Reports 1. Location and brief...

  7. Aquatic Plant Management Program current status and seasonal workplan

    Energy Technology Data Exchange (ETDEWEB)

    Burns, E.R.; Bates, A.L.; Webb, D.H.

    1993-07-01

    The objective of the TVA Aquatic Plant Management Program is to support in an environmentally and economically responsible manner, the balanced multiple uses of the water resource of the Tennessee Valley. This is accomplished by following an integrated approach to prevent introduction and spread of noxious species, documenting occurrence and spread of existing species, and suppressing or eliminating problems in designated high use areas. It is not the TVA objective, nor is it biologically feasible and prudent to eliminate all aquatic vegetation. Aerial photography, helicopter reconnaissance, and field surveys are used to assess distributions and abundance of various aquatic macrophytes. Water level fluctuations are supplemented by herbicide applications to control undesirable vegetation. Investigations are conducted to evaluate water level fluctuation schemes, as well as biological, mechanical, and alternative chemical control techniques which offer potential for more environmentally compatible and cost-effective management operations.

  8. Aquatic plants are open flexible structures - a reply to Sukhodolov

    DEFF Research Database (Denmark)

    Sand-Jensen, K.

    2005-01-01

    1. Aquatic plant stands are flexible, mesh-like open structures that undergo modification in shape and experience a cascade of declining flow velocities and micro-scale Reynolds numbers with increasing distance into the stands. It is not possible to define or measure the frontal area of this open...... flexible plant structure. Total wetted area was used as a reference area for drag because it can be measured with high accuracy and it was the most suitable measure of plant size impeding the flow and absorbing light for photosynthetic production. What is important is that it is made absolutely clear which...

  9. Selection of candidate aquatic high plants as producer of closed aquatic ecosystem

    Science.gov (United States)

    Wang, Gaohong; Hao, Zongjie; Liu, Yongding

    Controlled Ecological Life Support Systems (CELSS) is very important for long-term manned space flight. Aquatic organism was regarded to be suitable for this study because of their great adaptation to the weightless condition which approximate to their wild condition in water. In order to study of operation of CELSS in space, the first step is to choose good candidate species for study. In this report, we compared the characteristics of nutrient content, growth and suitability with animals among five types of aquatic high plants including Ceratophyllum demersum L., Vallisneria spiralis L., Hydrilla verticillata Royle, Brasenia schreberi, Wolfia arrhiza under control condition. It was found that B. schreberi had the best nutrients content, but it growth depended on gas interface which may be a big problem in microgravity. C. demersum and W. arrhiza had the better nutrient content than other types, and V. spiralis and H. verticillata had the worst nutrient content. The closed aquatic system can provided condition for the growth of other plants than B. schreberi. So we selected C. demersum and W. arrhiza as the candidate of producer for establish Closed Aquatic Ecosystem. We also established a simple system& by housing three small freshwater snails (Bulinus australianus) and C. demersum in a 500mL box with light and temperature control. The values about pH, oxygen concentration, temperature and light had been acquired by sensors in real time for about 3 month. It was found that plant's biomass increased for several days and then leveled off and the snails survive, and the atmosphere and biomass for food met snails' requirement during experiments.

  10. Culture Methodology for Experimental Investigations Involving Rooted Submersed Aquatic Plants.

    Science.gov (United States)

    1984-11-01

    Regrowth of hydrilla from axillary buds . J. Aquat. Plant Manage. 18:27-29. Langeland, K. A., Sutton, D. L. and Canfield, D. E., Jr. 1983. Growth response...Barko, Hardin, and Matthews 1982). Room temperatures (20 -25 C) are adequate for most species; however, some of the more subtropically occurring, exotic...species (e.g. H. verticillata) may benefit from higher temperatures (Van, Hailer, and Garrard 1978; Bowes, Holaday, and Hailer 1979; Barko and Smart

  11. Method for treating wastewater using microorganisms and vascular aquatic plants

    Science.gov (United States)

    Wolverton, B. C. (Inventor)

    1983-01-01

    A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

  12. Can Aquatic Plants Keep Pace with Climate Change?

    Science.gov (United States)

    Viana, Duarte S

    2017-01-01

    The persistence of species may depend upon their capacity to keep pace with climate change. However, dispersal has been ignored in the vast majority of studies that aimed at estimating and predicting range shifts as a response to climate change. Long distance dispersal (LDD) in particular might promote rapid range shifts and allow species to track suitable habitat. Many aquatic plant species are dispersed by birds and have the potential to be dispersed over hundreds of kilometers during the bird migration seasons. I argue that such dispersal potential might be critical to allow species to track climate change happening at unprecedented high rates. As a case study, I used dispersal data from three aquatic plant species dispersed by migratory birds to model range shifts in response to climate change projections. By comparing four dispersal scenarios - (1) no dispersal, (2) unlimited dispersal, (3) LDD aquatic plant species can adjust their ranges under a severe climate change scenario. Therefore, investigating the dispersal capacity of species, namely their LDD potential, may contribute to estimate the likelihood of species to keep pace with climate change.

  13. Removal of fluoride contamination in water by three aquatic plants.

    Science.gov (United States)

    Karmakar, Sukalpa; Mukherjee, Joydeep; Mukherjee, Somnath

    2016-01-01

    Phytoremediation, popularly known as 'green technology' has been employed in the present investigation to examine the potential of fluoride removal from water by some aquatic plants. Fluoride contamination in drinking water is very much prevalent in different parts of the world including India. Batch studies were conducted using some aquatic plants e.g., Pistia stratiotes, Eichhornia crassipes, and Spirodela polyrhiza which profusely grow in natural water bodies. The experimental data exhibited that all the above three aquatic floating macrophytes could remove fluoride to some relative degree of efficiency corresponding to initial concentration of fluoride 3, 5, 10, 20 mg/l after 10 days exposure time. Result showed that at lower concentration level i.e., 3 mg/L removal efficiency of Pistia stratiotes (19.87%) and Spirodela polyrhiza (19.23%) was found to be better as compared to Eichhornia crassipes (12.71%). Some of the physiological stress induced parameters such as chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, total protein, catalase, and peroxidase were also studied to explore relative damage within the cell. A marginal stress was imparted among all the plants for lower concentration values (3 mg/L), whereas at 20 mg/l, maximum damage was observed.

  14. Effects of invasive species on plant communities: an example using submersed aquatic plants at the regional level

    Science.gov (United States)

    Submerged aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects in the hydrological regime, sedimentation, nutrient cycling and habitats of associated fauna. Modifications of aquatic plant communities, as for example through the introduction of invasive s...

  15. Quantitative assessment of aquatic impacts of power plants

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

    1979-08-01

    Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers.

  16. Dinitrogen fixation associated with shoots of aquatic carnivorous plants: is it ecologically important?

    National Research Council Canada - National Science Library

    Sirová, Dagmara; Santrůček, Jiří; Adamec, Lubomír; Bárta, Jiří; Borovec, Jakub; Pech, Jiří; Owens, Sarah M; Santrůčková, Hana; Schäufele, Rudi; Storchová, Helena; Vrba, Jaroslav

    2014-01-01

    .... In this study, an investigation was made of the importance of microbial dinitrogen (N2) fixation in the N acquisition of four aquatic Utricularia species and another aquatic carnivorous plant, Aldrovanda vesiculosa...

  17. Water-Wisteria as an ideal plant to study heterophylly in higher aquatic plants.

    Science.gov (United States)

    Li, Gaojie; Hu, Shiqi; Yang, Jingjing; Schultz, Elizabeth A; Clarke, Kurtis; Hou, Hongwei

    2017-08-01

    The semi-aquatic plant Water-Wisteria is suggested as a new model to study heterophylly due to its many advantages and typical leaf phenotypic plasticity in response to environmental factors and phytohormones. Water-Wisteria, Hygrophila difformis (Acanthaceae), is a fast growing semi-aquatic plant that exhibits a variety of leaf shapes, from simple leaves to highly branched compound leaves, depending on the environment. The phenomenon by which leaves change their morphology in response to environmental conditions is called heterophylly. In order to investigate the characteristics of heterophylly, we assessed the morphology and anatomy of Hygrophila difformis in different conditions. Subsequently, we verified that phytohormones and environmental factors can induce heterophylly and found that Hygrophila difformis is easily propagated vegetatively through either leaf cuttings or callus induction, and the callus can be easily transformed by Agrobacterium tumefaciens. These results suggested that Hygrophila difformis is a good model plant to study heterophylly in higher aquatic plants.

  18. Biomechanical responses of aquatic plants to aerial conditions.

    Science.gov (United States)

    Hamann, Elena; Puijalon, Sara

    2013-12-01

    Wetlands are impacted by changes in hydrological regimes that can lead to periods of low water levels. During these periods, aquatic plants experience a drastic change in the mechanical conditions that they encounter, from low gravitational and tensile hydrodynamic forces when exposed to flow under aquatic conditions, to high gravitational and bending forces under terrestrial conditions. The objective of this study was to test the capacity of aquatic plants to produce self-supporting growth forms when growing under aerial conditions by assessing their resistance to terrestrial mechanical conditions and the associated morpho-anatomical changes. Plastic responses to aerial conditions were assessed by sampling Berula erecta, Hippuris vulgaris, Juncus articulatus, Lythrum salicaria, Mentha aquatica, Myosotis scorpioides, Nuphar lutea and Sparganium emersum under submerged and emergent conditions. The cross-sectional area and dry matter content (DMC) were measured in the plant organs that bear the mechanical forces, and their biomechanical properties in tension and bending were assessed. All of the species except for two had significantly higher stiffness in bending and thus an increased resistance to terrestrial mechanical conditions when growing under emergent conditions. This response was determined either by an increased allocation to strengthening tissues and thus a higher DMC, or by an increased cross-sectional area. These morpho-anatomical changes also resulted in increased strength and stiffness in tension. The capacity of the studied species to colonize this fluctuating environment can be accounted for by a high degree of phenotypic plasticity in response to emersion. Further investigation is however needed to disentangle the finer mechanisms behind these responses (e.g. allometric relations, tissue make-up), their costs and adaptive value.

  19. Can Aquatic Plants Keep Pace with Climate Change?

    Directory of Open Access Journals (Sweden)

    Duarte S. Viana

    2017-11-01

    Full Text Available The persistence of species may depend upon their capacity to keep pace with climate change. However, dispersal has been ignored in the vast majority of studies that aimed at estimating and predicting range shifts as a response to climate change. Long distance dispersal (LDD in particular might promote rapid range shifts and allow species to track suitable habitat. Many aquatic plant species are dispersed by birds and have the potential to be dispersed over hundreds of kilometers during the bird migration seasons. I argue that such dispersal potential might be critical to allow species to track climate change happening at unprecedented high rates. As a case study, I used dispersal data from three aquatic plant species dispersed by migratory birds to model range shifts in response to climate change projections. By comparing four dispersal scenarios – (1 no dispersal, (2 unlimited dispersal, (3 LDD < 100 km, and (4 LDD mediated by bird migratory movements –, it was shown that, for bird-mediated dispersal, the rate of colonization is sufficient to counterbalance the rate of habitat loss. The estimated rates of colonization (3.2–31.5 km⋅year-1 are higher than, for example, the rate of global warming (previously estimated at 0.42 km⋅year-1. Although further studies are needed, the results suggest that these aquatic plant species can adjust their ranges under a severe climate change scenario. Therefore, investigating the dispersal capacity of species, namely their LDD potential, may contribute to estimate the likelihood of species to keep pace with climate change.

  20. Ecogenotoxicity testing of aquatic environment by comet assay in plants

    Directory of Open Access Journals (Sweden)

    Anita Mukherjee

    2015-05-01

    Full Text Available One of the goals of environmental monitoring is the detection of potentially hazardous compounds in water. We have set up a standard method to apply the Comet assay in aquatic plants that could be of great interest to evaluate cytotoxicity, genotoxicity and oxidative stress on the same species regarded as most sensitive to environmental pollutants. The aim of the present study was to set up of standardized procedure to evaluate genotoxicity in aquatic plants- Ceratophyllum demersum one that is submerged free floating and the other is Lemna minor - a fresh water floating plant by Comet assay. Electrophoresis and unwinding times were adapted to obtain minimum DNA migration evaluated as tail intensity % or tail moment in the control group and, at the same time maximum sensitivity for DNA damage with known genotoxicants. We further investigated the cytotoxicity and oxidative stress induced in the same species. Based on the repeatability of results obtained we suggest that Ceratophyllum, Lemna can serve as model species and Comet assay could be adopted to monitor the eco-genotoxicity of water pollutants.

  1. Phytofabrication of silver nanoparticles by using aquatic plant Hydrilla verticilata

    Directory of Open Access Journals (Sweden)

    MAHENDRA RAI

    2012-07-01

    Full Text Available Sable N, Gaikwad S, Bonde S, Gade A, Rai M. 2012. Phytofabrication of silver nanoparticles by using aquatic plant Hydrilla verticilata. Nusantara Bioscience 4: 45-49. In the context of current drive to developed new green technology in nanomaterials, synthesis of nanoparticles is of considerable importance. There has been considerable work done in the field of nanoscience and nanotechnology during the last decade due to the introduction of various protocols for the synthesis of nanoparticles by using plants and microorganisms. Here we firstly report the extracellular phytosynthesis of silver nanoparticles (Ag-NPs using aquatic plants Hydrilla verticilata. The characterization of the phytosynthesized Ag-NPs was done with the help of UV-Vis spectroscopy, FTIR, Nanoparticle Tracking Analysis (NTA, Zeta potential and SEM. The SEM micrograph revealed the synthesis of polydispersed spherical nanoparticles, with the average size of 65.55 nm. The phytofabricated Ag-NPs can be used in the field of medicine and agriculture, due to their antimicrobial potential.

  2. Pathways of introduction of the invasive aquatic plant Cabomba caroliniana

    OpenAIRE

    McCracken, Andr?e; Bainard, Jillian D; Miller, Michelle C; Husband, Brian C

    2013-01-01

    The pathway and frequency of species' introductions can affect the extent, impact, and management of biological invasions. Here, we examine the pathway of introduction of the aquatic plant Cabomba caroliniana (fanwort) into Canada and the northern United States using plastid DNA sequence (intergenic spacers atpF-atpH, trnH-psbA, and trnL-trnF) and DNA content analyses. We test the hypothesis that the spread of fanwort is a result of commercial trade by comparing a Canadian population (Kasshab...

  3. Remote sensing analysis of Lake Livingston aquatic plants

    Science.gov (United States)

    Benton, A. R., Jr.; Newman, R. M.

    1976-01-01

    Results obtained during 1975 to monitor the growth of aquatic plants in the Lake Livingston area, using remote sensing photographic imagery, were described. Sequential total coverage was provided of the Jungle and White Rock Creek, plus coverage of smaller areas of localized infestation downlake, including Brushy Creek, KOA Kampground Marina, Penwaugh Slough, Memorial Point Marina, the Beacon Bay marinas and Pine Island. The imagery was generally good, photographic exposure being increased as the season progressed in order to obtain better pictures of the submerged vegetation. Some very significant differences in growth patterns, species interaction, and species dominance were observed when compared to 1974. Observation of the following plants was discussed: water hyacinth, hydrilla, coontail, potamageton. In general, the level of infestation was lower in 1975 than in 1974, due to the combined effect of more systematic application of herbicides and harsher intervening winter weather conditions.

  4. Aquatic Plant/microbial Filters for Treating Septic Tank Effluent

    Science.gov (United States)

    Wolverton, B. C.

    1988-01-01

    The use of natural biological processes for treating many types of wastewater have been developed by NASA at the John C. Stennis Space Center, NSTL, Mississippi, during the past 15 years. The simplest form of this technology involves the use of aquatic plant/marsh filters for treatment of septic tank effluent. Septic tank effluent from single home units can be treated to advanced secondary levels and beyond by using a 37.2 sq m (400 sq ft) surface area washed gravel filter. This filter is generally 0.3 m (1 ft) deep with a surface cover of approximately 0.15 m (6 in.) of gravel. The plants in this filter are usually aesthetic or ornamental such as calla lily (Zantedeschia aethiopica), canna lily (Canna flaccida), elephant ear (Colocasia esculenta), and water iris (Iris pseudacorus).

  5. Aquatic plants exposed to pharmaceuticals: effects and risks.

    Science.gov (United States)

    Brain, Richard A; Hanson, Mark L; Solomon, Keith R; Brooks, Bryan W

    2008-01-01

    Pharmaceuticals are biologically active, ubiquitous, low-level contaminants that are continuously introduced into the environment from both human and veterinary applications at volumes comparable to total pesticide loadings. Recent analytical advances have made possible the detection of a number of these compounds in environmental samples, raising concerns over potential nontarget effects to aquatic organisms, especially given the highly specific biologically active nature of these compounds. These concerns become paramount when the evolutionary conservation of metabolic pathways and receptors is taken into consideration, particularly in the case of aquatic plants, where a great deal of homology is displayed between the chloroplast and bacteria, as well as between other metabolic pathways across multiple phyla of biological organization. Common receptors have been identified in plants for a number of antibiotics affecting chloroplast replication (fluoroquinolones) transcription and translation (tetracyclines macrolides, lincosamides, P-aminoglycosides, and pleuromutilins), metabolic pathways such as folate biosynthesis (sulfonamides) and fatty acid biosynthesis (triclosan), as well as other classes of pharmaceuticals that affect sterol biosynthesis (statin-type blood lipid regulators). Toxicological investigations into the potency of these compounds indicates susceptibility across multiple plant species, although sensitivity to these compounds varies widely between blue-green algae, green algae, and higher plants in a rather inconsistent manner, except that Cyanobacteria are largely the most sensitive to antibiotic compounds. This differential sensitivity is likely dependent on differences in metabolic potential as well as uptake kinetics, which has been demonstrated for a number of compounds from another class of biologically active compounds, pesticides. The demonstration of conserved receptors and pathways in plants is not surprising, although it has been

  6. Biogeochemical features of aquatic plants in the Selenga River delta

    Science.gov (United States)

    Shinkareva, Galina; Lychagin, Mikhail

    2014-05-01

    The Selenga River system provides more than a half of the Lake Baikal total inflow. The river collects a significant amount of pollutants (e.g. heavy metals) from the whole basin. These substances are partially deposited within the Selenga delta, and partially are transported further to the lake. A generous amount of aquatic plants grow in the delta area according to its favorable conditions. This vegetation works as a specific biofilter. It accumulates suspended particles and sorbs some heavy metals from the water. The study aimed to reveal the species of macrophytes which could be mostly important for biomonitoring according to their chemical composition. The field campaign took place in the Selenga River delta in July-August of 2011 (high water period) and in June of 2012 (low water period). 14 species of aquatic plants were collected: water starwort Callitriche hermaphroditica, small yellow pond lily Nuphar pumila, pondweeds Potamogeton crispus, P. pectinatus, P. friesii, broadleaf cattail Typha latifolia, hornwort or coontail Ceratophyllum demersum, arrowhead Sagittaria natans, flowering rush (or grass rush) Butomus umbellatus, reed Phragmites australis, parrot's feather Myriophyllum spicatum, the common mare's tail Hippuris vulgaris, Batrachium trichophyllum, canadian waterweed Elodea canadensis. The samples were dried, grinded up and digested in a mixture of HNO3 and H2O2. The chemical composition of the plant material was defined using ICP-MS and ICP-AES methods. Concentrations of Fe, Mn, Cr, Ni, Cu, B, Zn, V, Co, As, Mo, Pb, and U were considered. The study revealed that Potamogeton pectinatus and Myriophyllum spicatum concentrate elements during both high and low water periods. Conversely the Butomus umbellatus and Phragmites australis contain small amount of heavy metals. The reed as true grasses usually accumulates fewer amounts of elements than other macrophytes. To compare biogeochemical specialization of different species we suggest to use

  7. Plant performance across latitude: the role of plasticity and local adaptation in a clonal aquatic plant

    NARCIS (Netherlands)

    Santamaria, L.; Figuerola, J.; Pilon, J.; Mjelde, M.; Green, A.J.; De Boer, T.; King, R.H.M.; Gornall, R.J.

    2003-01-01

    Geographic variation can lead to the evolution of different local varieties within a given species, therefore influencing its distribution and genetic structure. We investigated the contribution of plasticity and local adaptation to the performance of a common aquatic plant (Potamogeton pectinatus)

  8. Differentiating aquatic plant communities in a eutrophic river using hyperspectral and multispectral remote sensing

    Science.gov (United States)

    Tian, Y.Q.; Yu, Q.; Zimmerman, M.J.; Flint, S.; Waldron, M.C.

    2010-01-01

    This study evaluates the efficacy of remote sensing technology to monitor species composition, areal extent and density of aquatic plants (macrophytes and filamentous algae) in impoundments where their presence may violate water-quality standards. Multispectral satellite (IKONOS) images and more than 500 in situ hyperspectral samples were acquired to map aquatic plant distributions. By analyzing field measurements, we created a library of hyperspectral signatures for a variety of aquatic plant species, associations and densities. We also used three vegetation indices. Normalized Difference Vegetation Index (NDVI), near-infrared (NIR)-Green Angle Index (NGAI) and normalized water absorption depth (DH), at wavelengths 554, 680, 820 and 977 nm to differentiate among aquatic plant species composition, areal density and thickness in cases where hyperspectral analysis yielded potentially ambiguous interpretations. We compared the NDVI derived from IKONOS imagery with the in situ, hyperspectral-derived NDVI. The IKONOS-based images were also compared to data obtained through routine visual observations. Our results confirmed that aquatic species composition alters spectral signatures and affects the accuracy of remote sensing of aquatic plant density. The results also demonstrated that the NGAI has apparent advantages in estimating density over the NDVI and the DH. In the feature space of the three indices, 3D scatter plot analysis revealed that hyperspectral data can differentiate several aquatic plant associations. High-resolution multispectral imagery provided useful information to distinguish among biophysical aquatic plant characteristics. Classification analysis indicated that using satellite imagery to assess Lemna coverage yielded an overall agreement of 79% with visual observations and >90% agreement for the densest aquatic plant coverages. Interpretation of biophysical parameters derived from high-resolution satellite or airborne imagery should prove to be a

  9. Triclosan removal in wetlands constructed with different aquatic plants.

    Science.gov (United States)

    Liu, Jianing; Wang, Jingmin; Zhao, Congcong; Hay, Anthony G; Xie, Huijun; Zhan, Jian

    2015-10-22

    Triclosan (TCS) is widely used in consumer products as an antimicrobial agent. Constructed wetlands have the potential for TCS removal, but knowledge about the relative importance of sediment, plants, and microbes is limited. TCS removal performance was investigated in well-operated constructed wetlands planted with three different types of aquatic plants: emergent Cattail (C-T), submerged Hornwort (H-T), and floating Lemnaminor (L-T). Results showed that the TCS removal efficiencies from water were all greater than 97 %. Maximal TCS adsorption to sediment in the C-T wetland (13.8 ± 0.6 ng/g) was significantly lower than in the H-T wetland (21.0 ± 0.3 ng/g) or the L-T wetland (21.4 ± 0.6 ng/g). The maximal TCS concentrations in plants were 5.7 ± 0.2 and 7.2 ± 0.5 μg/g for H-T and L-T, respectively, and it was below the minimal detection limit (MDL) in C-T. Deep 16S rRNA gene sequencing results revealed that C-T wetland had the highest community richness and diversity. Some bacteria, like beta-Proteobacteria, gamma-Proteobacteria, and Bacteroidetes were detected and might have significant correlations with TCS degradation. Overall, with regard to soils, plants, and microorganism, accumulation in sediment and plants in H-T and L-T was high, while in C-T biodegradation likely played an important role.

  10. ent-Labdane diterpenes from the aquatic plant Potamogeton pectinatus.

    Science.gov (United States)

    Waridel, Patrice; Wolfender, Jean-Luc; Lachavanne, Jean-Bernard; Hostettmann, Kurt

    2003-12-01

    Four new ent-labdane diterpenes were isolated from the freshwater aquatic plant Potamogeton pectinatus, together with two known furano-ent-labdanes. The new compounds were assigned the structures methyl-15,16-epoxy-12(R)-acetoxy- 8(17), 13(16),14-ent-labdatrien-19-oate,15,16-epoxy-12(R)-acetoxy-8(17), 13(16),14-ent-labdatrien-19-oic acid, 8(17),13-ent-labdadien-15 --> 16-lactone-19-oic acid and 16-hydroxy-8(17),13-ent-labdadien-15,16-olid-19-oic acid by spectroscopic means. Some of these labdanes showed a strong algicidal activity against Raphidocelis subcapitata.

  11. Remote Sensing and Modeling for Improving Operational Aquatic Plant Management

    Science.gov (United States)

    Bubenheim, Dave

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  12. Study on MMW radiation characteristics and imaging of aquatic plants for environmental application

    Science.gov (United States)

    Zhou, Luyan; Zhang, Guangfeng; Liu, Jing

    2017-02-01

    Working all-day and all-weather, the passive millimeter wave radiometer is widely used in remote sensing, guidance and other fields. In order to solve the increasingly serious problem of water pollution, especially the pollution caused by the rapidly breed of the aquatic plants, a simple and effective method to monitor the water environment is proposed. Aquatic plants can be distinguished through millimeter wave system, as they have high bright temperature compared to Water. The 8mm radiometer is used to measure the radiation characteristics of aquatic plants and image. The simulation results and radiation imaging experiments prove the feasibility and effectively of monitoring aquatic plants by millimeter wave radiometer. This study will contribute to monitoring the aquatic plants growth and decreasing the pollution.

  13. Pathways of introduction of the invasive aquatic plant Cabomba caroliniana.

    Science.gov (United States)

    McCracken, Andrée; Bainard, Jillian D; Miller, Michelle C; Husband, Brian C

    2013-06-01

    The pathway and frequency of species' introductions can affect the extent, impact, and management of biological invasions. Here, we examine the pathway of introduction of the aquatic plant Cabomba caroliniana (fanwort) into Canada and the northern United States using plastid DNA sequence (intergenic spacers atpF-atpH, trnH-psbA, and trnL-trnF) and DNA content analyses. We test the hypothesis that the spread of fanwort is a result of commercial trade by comparing a Canadian population (Kasshabog Lake, ON) to native populations from southern U.S., introduced populations in northern U.S., and plants from commercial retailers. Thirteen plastid haplotypes were identified throughout North America, including one dominant haplotype, which was present in all C. caroliniana populations. Several rare haplotypes were used to infer shared colonization history. In particular, the Canadian population shared two rare alleles with a population from Massachusetts, suggesting range expansion of C. caroliniana from the northern U.S. However, the possibility of a commercial introduction cannot be excluded, as common alleles were shared between the Canadian population and both commercial and southern U.S. sources. Variation in C. caroliniana genome size was bimodal and populations were classified into "high" and "low" categories. The Canadian population had DNA contents similar to several northern U.S. populations (low DNA content). This may provide additional support for range expansion from these introduced populations rather than from commercial sources or populations in the southern U.S., which had high DNA content.

  14. Aquatic adventitious root development in partially and completely submerged wetland plants Cotula coronopifolia and Meionectes brownii.

    Science.gov (United States)

    Rich, Sarah Meghan; Ludwig, Martha; Colmer, Timothy David

    2012-07-01

    A common response of wetland plants to flooding is the formation of aquatic adventitious roots. Observations of aquatic root growth are widespread; however, controlled studies of aquatic roots of terrestrial herbaceous species are scarce. Submergence tolerance and aquatic root growth and physiology were evaluated in two herbaceous, perennial wetland species Cotula coronopifolia and Meionectes brownii. Plants were raised in large pots with 'sediment' roots in nutrient solution and then placed into individual tanks and shoots were left in air or submerged (completely or partially). The effects on growth of aquatic root removal, and of light availability to submerged plant organs, were evaluated. Responses of aquatic root porosity, chlorophyll and underwater photosynthesis, were studied. Both species tolerated 4 weeks of complete or partial submergence. Extensive, photosynthetically active, aquatic adventitious roots grew from submerged stems and contributed up to 90 % of the total root dry mass. When aquatic roots were pruned, completely submerged plants grew less and had lower stem and leaf chlorophyll a, as compared with controls with intact roots. Roots exposed to the lowest PAR (daily mean 4.7 ± 2.4 µmol m(-2) s(-1)) under water contained less chlorophyll, but there was no difference in aquatic root biomass after 4 weeks, regardless of light availability in the water column (high PAR was available to all emergent shoots). Both M. brownii and C. coronopifolia responded to submergence with growth of aquatic adventitious roots, which essentially replaced the existing sediment root system. These aquatic roots contained chlorophyll and were photosynthetically active. Removal of aquatic roots had negative effects on plant growth during partial and complete submergence.

  15. 33 CFR Appendix C to Part 273 - Information Requirements for Aquatic Plant Control Program Environmental Impact Statements

    Science.gov (United States)

    2010-07-01

    ... Aquatic Plant Control Program Environmental Impact Statements C Appendix C to Part 273 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE AQUATIC PLANT CONTROL Pt. 273, App. C Appendix C to Part 273—Information Requirements for Aquatic Plant Control Program...

  16. Field effectiveness of Bacillus thuringiensis israelensis (Bti) against Aedes (Stegomyia) aegypti (Linnaeus) in ornamental ceramic containers with common aquatic plants.

    Science.gov (United States)

    Chen, C D; Lee, H L; Nazni, W A; Seleena, B; Lau, K W; Daliza, A R; Ella Syafinas, S; Mohd Sofian, A

    2009-04-01

    This study was undertaken to determine the impact of larvaciding using a Bti (Bacillus thuringiensis israelensis) formulation (VectoBac WG) against Aedes aegypti larvae in earthen jars containing aquatic plants. Aquatic plants commonly used for landscaping, Pistia stratiotes (L.) (Liliopsida: Araceae) and Sagittaria sp. (Liliopsida: Alismataceae) were placed inside earthen jars filled with 50 L tap water. All earthen jars were treated with Bti formulation at 8g/1000L. Untreated jars with and without aquatic plants were also set up as controls. Fifty laboratory-bred 2nd instar larvae were introduced into each earthen jar. All earthen jars were observed daily. Number of adults emerged was recorded and the larval mortality was calculated. The indicators of effectiveness of Bti for these studies were (i) residual activities of Bti, and (ii) larval mortality in earthen jars with or without aquatic plants. The treated earthen jars containing P. stratiotes and Sagittaria sp. showed significant residual larvicidal effect up to 7 weeks, in comparison to untreated control (p aquatic plants vs 80.66% - 100% for jars without aquatic plant. Earthen jars treated with Bti without aquatic plants also exhibited significantly longer residual larvicidal activity of up to 10 weeks (p aquatic plants vs 59.34% - 100% for jars without aquatic plant. Thus, earthen jars without aquatic plants exhibited longer residual larvicidal effect compared to those with aquatic plants. This study suggested that containers with aquatic plants for landscaping should be treated more frequently with Bti in view of the shortened residual activity.

  17. Remote sensing of aquatic plants. [New York, Florida, Texas, Louisiana, Mississippi, South Carolina

    Science.gov (United States)

    Long, K. S.; Link, L. E., Jr.

    1977-01-01

    Various sensors were tested in terms of their ability to detect and discriminate among noxious aquatic macrophytes. A survey of researchers currently studying the problem and a brief summary of their work is included. Results indicated that the sensor types best suited to assessment of the aquatic environment are color, color infrared, and black-and-white infrared film, which furnish consistently high contrasts between aquatic plants and their surroundings.

  18. Biomass or growth rate endpoint for algae and aquatic plants: relevance for the aquatic risk assessment of herbicides.

    Science.gov (United States)

    Bergtold, Matthias; Dohmen, Gerhard Peter

    2011-04-01

    Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values separately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment. Copyright © 2010 SETAC.

  19. Environmental Assessment: Submerged Aquatic Plant Management of Banks Lake, Banks Lake NWR, Lakeland, Georgia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is an analysis of five alternatives developed to address themanagement of the submerged aquatic plants of Banks Lake on Banks Lake...

  20. Potential Use of Native and Naturalized Insect Herbivores and Fungal Pathogens of Aquatic and Wetland Plants

    National Research Council Canada - National Science Library

    Freedman, Jan E; Grodowitz, Michael J; Swindle, Robin; Nachtrieb, Julie G

    2007-01-01

    ...) scientists to identify naturalized and/or native herbivores of aquatic plants in an effort to develop alternative management strategies through an understanding of the agents' biology and ecology...

  1. Aquatic plant Azolla as the universal feedstock for biofuel production.

    Science.gov (United States)

    Miranda, Ana F; Biswas, Bijoy; Ramkumar, Narasimhan; Singh, Rawel; Kumar, Jitendra; James, Anton; Roddick, Felicity; Lal, Banwari; Subudhi, Sanjukta; Bhaskar, Thallada; Mouradov, Aidyn

    2016-01-01

    The quest for sustainable production of renewable and cheap biofuels has triggered an intensive search for domestication of the next generation of bioenergy crops. Aquatic plants which can rapidly colonize wetlands are attracting attention because of their ability to grow in wastewaters and produce large amounts of biomass. Representatives of Azolla species are some of the fastest growing plants, producing substantial biomass when growing in contaminated water and natural ecosystems. Together with their evolutional symbiont, the cyanobacterium Anabaena azollae, Azolla biomass has a unique chemical composition accumulating in each leaf including three major types of bioenergy molecules: cellulose/hemicellulose, starch and lipids, resembling combinations of terrestrial bioenergy crops and microalgae. The growth of Azolla filiculoides in synthetic wastewater led up to 25, 69, 24 and 40 % reduction of NH4-N, NO3-N, PO4-P and selenium, respectively, after 5 days of treatment. This led to a 2.6-fold reduction in toxicity of the treated wastewater to shrimps, common inhabitants of wetlands. Two Azolla species, Azolla filiculoides and Azolla pinnata, were used as feedstock for the production of a range of functional hydrocarbons through hydrothermal liquefaction, bio-hydrogen and bio-ethanol. Given the high annual productivity of Azolla, hydrothermal liquefaction can lead to the theoretical production of 20.2 t/ha-year of bio-oil and 48 t/ha-year of bio-char. The ethanol production from Azolla filiculoides, 11.7 × 103 L/ha-year, is close to that from corn stover (13.3 × 103 L/ha-year), but higher than from miscanthus (2.3 × 103 L/ha-year) and woody plants, such as willow (0.3 × 103 L/ha-year) and poplar (1.3 × 103 L/ha-year). With a high C/N ratio, fermentation of Azolla biomass generates 2.2 mol/mol glucose/xylose of hydrogen, making this species a competitive feedstock for hydrogen production compared with other bioenergy crops. The high

  2. A simple method to estimate spatial complexity in aquatic plants

    Directory of Open Access Journals (Sweden)

    Eric David Dibble

    2006-05-01

    Full Text Available We used a computerized approach to measure spatial complexity for the structural habitat provided by eight aquatic plant species collected from backwater lagoons located in the Upper Paraná River floodplain, Brazil. The plant species were: Cabomba furcata Schult. and Schult.f., Eichhornia azurea (Sw. Kunth (stems and roots, Eichhornia crassipes (Mart. Solms, Egeria najas Planchon, Heteranthera cf. zosterifolia, Potamogeton cf pusillus, Utricularia foliosa L., and Nymphaea amazonum Mart. and Zucc. The upper 0.5 m length of the terminal stems was quantified for complexity. Mean frequency and length of the interstices were significantly different among plant species. Spatial complexity varied (F = 17.30; p Neste trabalho foi medida a complexidade espacial que contribui para a estrutura de habitat proporcionada por 8 espécies de plantas aquáticas coletadas em lagoas da planície de inundação do alto rio Paraná. As espécies analisadas foram Cabomba furcata Schult. and Schult.f. Eichhornia azurea (Sw. Kunth (caules e raízes, Eichhornia crassipes (Mart. Solms, Egeria najas Planchon, Heteranthera cf. zosterifolia, Potamogeton cf pusillus, Utricularia foliosa L. e Nymphaea amazonum Mart. and Zucc. A complexidade dos segmentos terminais de 0,5 m foi medida em laboratório. Fotografias digitais desses segmentos foram feitas e análises dos eixos verticais e horizontais foram realizadas ao longo de transecções superpostas às imagens, em computador. A freqüência e o comprimento dos insterstícios ao longo de ambos os eixos foram tomados para determinar o índice de complexidade espacial. A freqüência e o comprimento médios dos interstícios foram significativamente diferentes entre as espécies de plantas. A complexidade espacial também variou entre as espécies (F = 17,30; p < 0,0001, com as raízes de E. azurea e U. foliosa exibindo os maiores valores e os caules de E. azurea e N. amazonum os menores. Estes valores da complexidade espacial

  3. Effects of Elimination of Alligator Weed on Certain Aquatic Plants and the Value of these Plants as Waterfowl Foods

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The effects of elimination of alligatorweed by granular silvex on the abundance of 12 species of aquatic plants were studied on the Santee National Wildlife Refuge,...

  4. Insect herbivory on native and exotic aquatic plants: phosphorus and nitrogen drive insect growth and nutrient release

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, E.M.; Bakker, E.S.

    2016-01-01

    Eutrophication and globalisation facilitate the dominance of exotic plants in aquatic ecosystems worldwide. Aquatic omnivores can provide biotic resistance to plant invasions, but little is known about whether obligate aquatic herbivores can do the same. Herbivores such as insects can decimate

  5. Broad-Scale Comparison of Photosynthesis in Terrestrial and Aquatic Plant Communities

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Krause-Jensen, D.

    1997-01-01

    Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... communities probably due to more efficient light utilization and gas exchange in the terrestrial habitats. By contrast only small differences were found within different aquatic plant communities or within different terrestrial plant communities.......Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... of forests, grasslands and crops and 319 aquatic studies of phytoplankton, macrophyte and attached microalgal communities to test if specific differences existed between the communities. Maximum gross photosynthesis and photosynthetic efficiency were systematically higher in terrestrial than in aquatic...

  6. The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil

    Directory of Open Access Journals (Sweden)

    Aurélio R. Meneses

    2013-09-01

    Full Text Available The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil. The aquatic caterpillar Paracles klagesi (Rothschild, 1910 was collected from the headwaters of a stream in an ecotone between Cerrado and Babaçu forest in northeastern Brazil. The single caterpillar found was observed feeding on the macrophyte Tonina fluviatilis Aubl. (Eriocaulaceae and other aquatic plants of the family Nymphaeaceae present in the area, but also accepted as food Elodea canadensis Michx. (Hydrocharitaceae and Cabomba sp. (Cabombaceae under laboratory conditions.

  7. Improving Aquatic Plant Management in the California Sacramento-San Joaquin Delta

    Science.gov (United States)

    Bubenheim, David L.; Potter, Chris

    2018-01-01

    Management of aquatic weeds in complex watersheds and river systems present many challenges to assessment, planning and implementation of management practices for floating and submerged aquatic invasive plants. The Delta Region Areawide Aquatic Weed Project (DRAAWP), a USDA sponsored area-wide project, is working to enhance planning, decision-making and operational efficiency in the California Sacramento-San Joaquin Delta. Satellite and airborne remote sensing are used map (area coverage and biomass), direct operations, and assess management impacts on plant communities. Archived satellite records going are used to review results from previous climate and management events and aide in developing long-term strategies. Modeling at local and watershed scales provides insight into land-use effects on water quality. Plant growth models informed by remote sensing are being applied spatially across the Delta to balance location and type of aquatic plant, growth response to altered environments, phenology, environmental regulations, and economics in selection of management practices. Initial utilization of remote sensing tools developed for mapping of aquatic invasive weeds improved operational efficiency by focusing limited chemical use to strategic areas with high plant-control impact and incorporating mechanical harvesting when chemical use is restricted. These assessment methods provide a comprehensive and quantitative view of aquatic invasive plants communities in the California Delta, both spatial and temporal, informed by ecological understanding with the objective of improving management and assessment effectiveness.

  8. Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater.

    Science.gov (United States)

    Rezania, Shahabaldin; Taib, Shazwin Mat; Md Din, Mohd Fadhil; Dahalan, Farrah Aini; Kamyab, Hesam

    2016-11-15

    Environmental pollution specifically water pollution is alarming both in the developed and developing countries. Heavy metal contamination of water resources is a critical issue which adversely affects humans, plants and animals. Phytoremediation is a cost-effective remediation technology which able to treat heavy metal polluted sites. This environmental friendly method has been successfully implemented in constructed wetland (CWs) which is able to restore the aquatic biosystem naturally. Nowadays, many aquatic plant species are being investigated to determine their potential and effectiveness for phytoremediation application, especially high growth rate plants i.e. macrophytes. Based on the findings, phytofiltration (rhizofiltration) is the sole method which defined as heavy metals removal from water by aquatic plants. Due to specific morphology and higher growth rate, free-floating plants were more efficient to uptake heavy metals in comparison with submerged and emergent plants. In this review, the potential of wide range of aquatic plant species with main focus on four well known species (hyper-accumulators): Pistia stratiotes, Eicchornia spp., Lemna spp. and Salvinia spp. was investigated. Moreover, we discussed about the history, methods and future prospects in phytoremediation of heavy metals by aquatic plants comprehensively. Copyright © 2016. Published by Elsevier B.V.

  9. Internal and External Dispersal of Plants by Animals: An Aquatic Perspective on Alien Interference

    Directory of Open Access Journals (Sweden)

    Casper H. A. van Leeuwen

    2018-02-01

    Full Text Available Many alien plants use animal vectors for dispersal of their diaspores (zoochory. If alien plants interact with native disperser animals, this can interfere with animal-mediated dispersal of native diaspores. Interference by alien species is known for frugivorous animals dispersing fruits of terrestrial plants by ingestion, transport and egestion (endozoochory. However, less attention has been paid to possible interference of alien plants with dispersal of diaspores via external attachment (ectozoochory, epizoochory or exozoochory, interference in aquatic ecosystems, or positive effects of alien plants on dispersal of native plants. This literature study addresses the following hypotheses: (1 alien plants may interfere with both internal and external animal-mediated dispersal of native diaspores; (2 interference also occurs in aquatic ecosystems; (3 interference of alien plants can have both negative and positive effects on native plants. The studied literature revealed that alien species can comprise large proportions of both internally and externally transported diaspores. Because animals have limited space for ingested and adhering diaspores, alien species affect both internal and external transport of native diaspores. Alien plant species also form large proportions of all dispersed diaspores in aquatic systems and interfere with dispersal of native aquatic plants. Alien interference can be either negative (e.g., through competition with native plants or positive (e.g., increased abundance of native dispersers, changed disperser behavior or attracting additional disperser species. I propose many future research directions, because understanding whether alien plant species disrupt or facilitate animal-mediated dispersal of native plants is crucial for targeted conservation of invaded (aquatic plant communities.

  10. Transfer of oxytetracycline from swine manure to three different aquatic plants: implications for human exposure.

    Science.gov (United States)

    Boonsaner, Maliwan; Hawker, Darryl W

    2015-03-01

    Little is known regarding the potential for pharmaceuticals including antibiotics to be accumulated in edible aquatic plants and enter the human food chain. This work investigates the transfer of a widely used veterinary antibiotic, oxytetracycline (OTC), from swine manure to aquatic plants by firstly characterizing desorption from swine manure to water and fitting data to both nonlinear and linear isotherms. Bioconcentration of OTC from water was then quantified with aquatic plants of contrasting morphology and growth habit viz. watermeal (Wolffia globosa Hartog and Plas), cabomba (Cabomba caroliniana A. Gray) and water spinach (Ipomoea aquatica Forsk.). Watermeal and water spinach are widely consumed in Southeast Asia. The OTC desorption and bioconcentration data were used to provide the first quantitative estimates of human exposure to OTC from a manure-water-aquatic plant route. Results show that under certain conditions (plants growing for 15d in undiluted swine manure effluent (2% w/v solids) and an initial OTC swine manure concentration of 43mgkg(-1) (dry weight)), this pathway could provide a significant fraction (>48%) of the acceptable daily intake (ADI) for OTC. While effluent dilution, lower OTC manure concentrations and not all plant material consumed being contaminated would be expected to diminish the proportion of the ADI accumulated, uptake from aquatic plants should not be ignored when determining human exposure to antibiotics such as OTC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. [Development characteristics of aquatic plants in a constructed wetland for treating urban drinking water source at its initial operation stage].

    Science.gov (United States)

    Zheng, Jun; Ma, Xin-Tang; Zhou, Lan; Zhou, Qing-Yuan; Wang, Zhong-Qiong; Wang, Wei-Dong; Yin, Cheng-Qing

    2011-08-01

    The development characteristics and improvement measures of aquatic plants were studied in Shijiuyang Constructed Wetland (SCW) at its initial operation stage. SCW was a large-scale wetland aiming to help relieve the source water pollution in Jiaxing City. A checklist of vascular plants in SCW was built, and species composition, life forms, biomass and association distributions were examined. Our objectives were to examine the diversity and community structure of aquatic plants in SCW at its initial operation stage, and to find out the possible hydrophyte improvement measures. The survey results showed that there were 49 vascular plant species belonging to 41 genera, 25 families in SCW, which greatly exceeded the artificially transplanted 13 species. The life forms of present aquatic plants in SCW were dominated by hygrophilous plants (20 species) and emerged plants (17 species), which accounted for 75.5% of the total number of aquatic plants. The aquatic plants transplanted artificially were dominated by emerged plants (accounted for 69.2%), while those naturally developed were predominated by hygrophilous plants (accounted for 47.2%). The horizontal distribution of aquatic plant community in SCW was mixed in the form of mosaics, which made up typical association complex. Except association Aeschynomene indica L., the dominant species of other associations were all those transplanted artificially. The naturally grown species scattered throughout the SCW and only occupied a small percentage. A marked difference was detected on the species and species richness of aquatic plants in different regions of SCW. Biomass of aquatic plant associations in SCW was 167.7 t. SCW has shown a trend of succession heading for quick increase of plant diversity at the primary operation stage. This trend provides a good material base for the future stable community of aquatic plants in SCW. According to the current status of aquatic plants, some suggestions were put forward on the

  12. Treatment with aquatic plants by a Bagdi tribal healer of Rajbari District, Bangladesh.

    Science.gov (United States)

    Mukti, Mohsina; Rahmatullah, Mohammed

    2013-07-01

    Tribal healers mainly use land plants in their medicinal formulations; use of aquatic plants has been scarcely reported. The aim of the present study was to conduct an ethnomedicinal survey working with a Bagdi tribal healer of Rajbari District, Bangladesh. The survey was carried out working with a Bagdi healer, who lived alone in the wetlands of Rajbari District and used primarily aquatic plants for treatment. Interview of the healer was carried out with the help of a semi-structured questionnaire and the guided field-walk method. The Bagdi healer was observed to use seven different aquatic plant species coming from five plant families for treatment of ailments such as hemorrhoids, tonsillitis, heart disorders, burning sensations and pain in hands or legs, blurred vision, debility, sexual weakness in males, chronic dysentery, infertility in women, constipation, chronic leucorrhea, blackness and foul odor of menstrual blood, hair loss, graying of hair and to keep the head cool. One plant was used to treat what the healer mentioned as "evil eye", this refers to their belief in black-magic. This is the first reported instance of a Bagdi healer who primarily uses aquatic plants for treatment. Ethnomedicinal uses of a number of the plants used by the Bagdi healer have been reported for other places in India and Pakistan. Taken together, the various uses of the different plant species opens up scientific possibilities of new drug discoveries from the plants.

  13. Effect of different water temperatures on growth of aquatic plants Salvinia natans and Ceratophyllum demersum

    Directory of Open Access Journals (Sweden)

    Khadija Kadhem Hreeb

    2016-12-01

    Full Text Available Objective: To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans and Ceratophyllum demersum. Methods: The aquatic plants were brought from Shatt Al-Arab River in 2016. Equal weights of aquatic plants were aquacultured in aquaria, and were exposed to three different temperatures ( 12, 22 and 32 °C. Results: The results showed that the two plants did not show significant differences with respect to their effects on pH and electrical conductivity values. Time and temperature did not affect the values of pH and electrical conductivity. The values of dissolved oxygen was significantly influenced with variation of time and temperature, while the two plants did not have significant differences on dissolved oxygen values, nitrate ion concentration and was not significantly influenced with variation of plant species or temperature or time. Plant species and temperature significantly affected phosphate ion concentration, while the time did not significantly influence the concentration of phosphate ion. Chlorophyll a content and biomass were significantly influenced with the variation of plant species, and temperature . Conclusions: Aquatic plants has a species specific respond to temperatures change in their environment. Water plant, Ceratophyllum demersum is more tolerant to temperatures change than Salvinia natans.

  14. Aquatic Plants: Management and Control. Special Circular 222.

    Science.gov (United States)

    Wingard, R. G.; And Others

    This publication, produced by the Pennsylvania Cooperative Extension Service, is a non-technical guide to chemical control of aquatic vegetation. The purpose of this circular is to aid the land owner or manager in managing ponds, streams, and other water bodies for desired uses by managing the vegetation in, on, and around the water. Among the…

  15. Aquatic plants as potential sources of antimicrobial compounds ...

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Minas Gerais, Brazil. Accepted 25 May, 2011. Resistance of pathogens to common veterinary antibiotics hampers mastitis treatment and motivates the discovery of new antimicrobials. In this study, extracts from two aquatic ...

  16. Crassulacean acid metabolism enhances underwater photosynthesis and diminishes photorespiration in the aquatic plant Isoetes australis

    DEFF Research Database (Denmark)

    Pedersen, Ole; Rich, S.M.; Pulido Pérez, Cristina

    2011-01-01

    Underwater photosynthesis by aquatic plants is often limited by low availability of CO2, and photorespiration can be high. Some aquatic plants utilize crassulacean acid metabolism (CAM) photosynthesis. The benefits of CAM for increased underwater photosynthesis and suppression of photorespiration......, it became negative in those low in malate. • CAM in aquatic plants enables higher rates of underwater net photosynthesis over large O2 and CO2 concentration ranges in floodwaters, via increased CO2 fixation and suppression of photorespiration....... were evaluated for Isoetes australis, a submerged plant that inhabits shallow temporary rock pools. • Leaves high or low in malate were evaluated for underwater net photosynthesis and apparent photorespiration at a range of CO2 and O2 concentrations. • CAM activity was indicated by 9.7-fold higher leaf...

  17. Aquatic fate of aerially applied hexazinone and terbuthylazine in a New Zealand planted forest

    Science.gov (United States)

    Brenda R. Baillie; Daniel G. Neary; Stefan Gous; Carol A. Rolando

    2015-01-01

    Herbicides are used to control competing vegetation during tree establishment, and are often critical to the productivity and economic viability of a planted forest crop. Despite increasing public concern over herbicide use in planted forests and potential impact on the environment, there is limited information on the aquatic fate of many of these herbicides when...

  18. Impact of native and non-native aquatic plants on methane emission and phytoplankton growth

    NARCIS (Netherlands)

    Grutters, B.M.C.; Aben, Ralf Cornelis; Kosten, S.; Bakker, E.S.

    2017-01-01

    Freshwater plants affect the ecosystem functioning of shallow aquatic ecosystems. However, because native plants are threatened by environmental change such as eutrophication, global warming and biological invasions, continued ecosystem functioning may be at risk. In this study, we explored how the

  19. Fate of methane in aquatic systems dominated by free-floating plants

    NARCIS (Netherlands)

    Kosten, Sarian; Piñeiro, Marcia; Goede, de Eefje; Klein, de Jeroen; Lamers, Leon P.M.; Ettwig, Katharina

    2016-01-01

    Worldwide the area of free-floating plants is increasing, which can be expected to alter methane (CH4) emissions from aquatic systems in several ways. A large proportion of the CH4 produced may become oxidized below the plants due to the accumulation of CH4 as a

  20. Invasion strategies in clonal aquatic plants: Are phenotypic differences caused by phenotypic plasticity or local adaptation?

    DEFF Research Database (Denmark)

    Riis, Tenna; Lambertini, Carla; Olesen, Birgit

    2010-01-01

    populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis...... and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained by local nutrient conditions. All together this strongly suggests that invasive clonal aquatic plants adapt to a wide......Background and Aims: The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important...

  1. Use of dried aquatic plant roots to adsorb heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, K.D.

    1996-12-31

    The removal of heavy metal ions by dried aquatic macrophytes was investigated. The ability of the biomass, Eichhornia crassipes (water hyacinth), Typha latifolia (cattail), Sparganium minimum (burr reed) and Menyanthes trifoliata to abstract lead and mercury ions is presented here, along with a conceptual filter design. This paper examines an alternative to both the traditional and recent systems designed for metal removal. It involves the use of dried aquatic macrophytes. There are numerous advantages for the use of dried macrophytes in the treatment of industrial wastewater. First, it is cost-effective. There are also funding opportunities through a variety of Environmental Protection Agency`s (EPA) programs. It is more environmentally conscious because a wetland, the harvesting pond, has been created. And, it creates public goodwill by providing a more appealing, less hardware-intensive, natural system.

  2. State of Washington, Aquatic Plant Management Program: Design Memorandum.

    Science.gov (United States)

    1979-10-01

    Winn. & Grab 4Water Plantain Alisma n~lantaqo-,AOuatica L. 4.Soft Rush Juncus effusus var. p acificus jFe rn & -Wi e-g. Saw-beak Sedge Carex stirata...Muhl. ex Willd. Table 2. Aquatic macrophytes of the Osoyoos Lake and Okanogan River. Carex sp. Ceratophyllun demerswn Chara spp. Eleocharis palustris...Black-bellied plover qatoraa sguator Surfbird Aphriza virata 1m Table 6. (Continued) Ruddy turnstone Arenaria interprkzs Black turnstone Arenaria

  3. Morphological strategies of Cabomba (Cabombaceae), a genus of aquatic plants

    OpenAIRE

    Lima, Carla Teixeira de; Santos, Francisco de Assis Ribeiro dos; Giulietti, Ana Maria

    2014-01-01

    This paper describes the vegetative and reproductive morphology of Cabombaceae species in Brazil, discussing its strategies for survival in an aquatic habitat. Through studies in the field, in cultivation and in the herbarium, we examined the following species: Cabomba aquatica, C. caroliniana, C. furcata and C. haynesii. In cultivation, only C. aquatica, C. furcata and C. haynesii produced flowers. In those three species, the flowers opened during the day on two consecutive days, submerging ...

  4. [Effects of aquatic plants during their decay and decomposition on water quality].

    Science.gov (United States)

    Tang, Jin-Yan; Cao, Pei-Pei; Xu, Chi; Liu, Mao-Song

    2013-01-01

    Taking 6 aquatic plant species as test objects, a 64-day decomposition experiment was conducted to study the temporal variation patterns of nutrient concentration in water body during the process of the aquatic plant decomposition. There existed greater differences in the decomposition rates between the 6 species. Floating-leaved plants had the highest decomposition rate, followed by submerged plants, and emerged plants. The effects of the aquatic plant species during their decomposition on water quality differed, which was related to the plant biomass density. During the decomposition of Phragmites australis, water body had the lowest concentrations of chemical oxygen demand, total nitrogen, and total phosphorus. In the late decomposition period of Zizania latifolia, the concentrations of water body chemical oxygen demand and total nitrogen increased, resulting in the deterioration of water quality. In the decomposition processes of Nymphoides peltatum and Nelumbo nucifera, the concentrations of water body chemical oxygen demand and total nitrogen were higher than those during the decomposition of other test plants. In contrast, during the decomposition of Potamogeton crispus and Myriophyllum verticillatum, water body had the highest concentrations of ammonium, nitrate, and total phosphorus. For a given plant species, the main water quality indices had the similar variation trends under different biomass densities. It was suggested that the existence of moderate plant residues could effectively promote the nitrogen and phosphorus cycles in water body, reduce its nitrate concentration to some extent, and decrease the water body nitrogen load.

  5. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Jacobsen, Dean

    2002-01-01

    1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...... production (average 1.2-5.1%) than aquatic populations (2.9-17.3%), while the same plant dry mass was consumed per unit ground area. 3. Grazing loss increased linearly with leaf age apart from the youngest leaf stages. Grazing loss during the lifetime of leaves was therefore 2.4-3.1 times higher than mean...... apparent loss to standing leaves of all ages. The results imply that variation in density of grazers relative to plant production can account for differences in grazing impact between terrestrial and aquatic populations, and that fast leaf turnover keeps apparent grazing damage down. 4. We conclude...

  6. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

    Science.gov (United States)

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-11-26

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

  7. Comparative Studies of the Phytoextraction Capacity of Five Aquatic Plants in Heavy Metal Contaminated Water

    OpenAIRE

    Buta, Erzsébet; Anamária TÖRÖK; Bilassé ZONGO; Maria CANTOR; Mihai BUTA; Majdik, Cornelia

    2014-01-01

    The uptake capacity of the aquatic plants (Salvinia natans Kunth., Eichhornia crassipes Mart., Lemna minor L., Elodea canadensis Michx., Pistia stratiotes L.) was analyzed in phytoextraction of Cu2+, Zn2+, and Cd2+. It was attend to study the plants capacity comparatively using mono and multimetallic systems. In particular, the chlorophyll, protein and carotenoids contents were studied during heavy metals uptake, in order to observe the stress effect on plants. The results obtained for the m...

  8. Evaluation of the Environmental DNA Method for Estimating Distribution and Biomass of Submerged Aquatic Plants.

    Science.gov (United States)

    Matsuhashi, Saeko; Doi, Hideyuki; Fujiwara, Ayaka; Watanabe, Sonoko; Minamoto, Toshifumi

    2016-01-01

    The environmental DNA (eDNA) method has increasingly been recognized as a powerful tool for monitoring aquatic animal species; however, its application for monitoring aquatic plants is limited. To evaluate eDNA analysis for estimating the distribution of aquatic plants, we compared its estimated distributions with eDNA analysis, visual observation, and past distribution records for the submerged species Hydrilla verticillata. Moreover, we conducted aquarium experiments using H. verticillata and Egeria densa and analyzed the relationships between eDNA concentrations and plant biomass to investigate the potential for biomass estimation. The occurrences estimated by eDNA analysis closely corresponded to past distribution records, and eDNA detections were more frequent than visual observations, indicating that the method is potentially more sensitive. The results of the aquarium experiments showed a positive relationship between plant biomass and eDNA concentration; however, the relationship was not always significant. The eDNA concentration peaked within three days of the start of the experiment in most cases, suggesting that plants do not release constant amounts of DNA. These results showed that eDNA analysis can be used for distribution surveys, and has the potential to estimate the biomass of aquatic plants.

  9. Aquatic Plant Control Research Program: Review of Senescence as an Important Factor Determining the Relationship Among Aquatic Plants, Their Epiphytes, and Pathogens

    Science.gov (United States)

    1989-04-01

    in old age, namely errors committed by the molecular genetic apparatus during protein syn- thesis (Leshem 1986). The term "senescence" has a somewhat...34Biologically Active Sulphur Compounds from the Green Alga Chara globularis," Phytochemistry , Vol 19, pp 1228-1229. Aurand, D. 1982. "Nuisance Aquatic Plants...579. Bayley, S. 1970. "The Ecology and Disease of Eurasian Watermilfoil (Myriophyllwn spicatum L.) in the Chesapeake Bay," Ph.D. thesis , Johns

  10. Uptake of inorganic phosphorus by the aquatic plant Isoetes australis inhabiting oligotrophic vernal rock pools

    DEFF Research Database (Denmark)

    Christiansen, Nina Høj; Pulido Pérez, Cristina; Pedersen, Ole

    2017-01-01

    The submerged aquatic freshwater macrophyte Isoetes australis S. Williams grows in rock pools situated in south-western Australia, an environment where dissolved inorganic phosphorus (Pi) availability possibly limits growth. In contrast to the two coexisting aquatic species, Glossostigma drummundii...... experiment revealed high amounts of Pi translocation internally in the plant which seemed to go from roots and oldest leaves to younger leaves. As a result of the high root to shoot ratio, high surface area, root uptake kinetics, and sediment Pi availability, roots accounted for 87% of plant Pi uptake...

  11. Uptake, translocation and metabolism of decabromodiphenyl ether (BDE-209) in seven aquatic plants.

    Science.gov (United States)

    Deng, Daiyong; Liu, Jin; Xu, Meiying; Zheng, Guolu; Guo, Jun; Sun, Guoping

    2016-06-01

    Terrestrial plant uptake of PBDEs from contaminated soils has been widely reported recently. In this study the fate of deca-BDE within a plant/PBDEs/aquatic environment system was investigated through simulated pot experiments. Accumulations of the total PBDEs and deca-BDE were observed in tissues of seven test aquatic plant species, namely Phragmites australis, Cyperus papyrus, Alternanthera philoxeroides, Colocasia esculenta, Scirpus validus, Acorus calamus and Oryza sativa. In all seven plants, O. sativa leads the uptake and accumulation both in the total PBDEs (444.8 ng g(-1)) and deca-BDE (368.0 ng g(-1)) in roots. Among the six common phytoremediation aquatic plants, A. calamus leads the uptake (236.2 ng g(-1)), and P. australis leads the translocation (Cshoot/Croot = 0.35), while A. philoxeroides (43.4%) and P. australis (80.0%) lead in the metabolism efficiencies in the root and shoot, respectively. The detection of seventeen lesser brominated PBDE congeners provided the debromination evidence, and the specific PBDEs profiles in test plant species indicated there is no common metabolic pattern. Furthermore, a relative high proportion of lesser brominated PBDE congeners in shoots suggested the possible metabolic difference between roots and shoots. Finally, a noticeable percentage of penta- and octa-BDE derived from deca-BDE also hint the ecological risk in deca-BDE use. This comparative research on the aquatic plants provide a broad vision on the understanding of plant/PBDEs/aquatic environment interaction system, and may be applied to remediate PBDEs in contaminated waters and sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Oxidation mechanism and overall removal rates of endocrine disrupting chemicals by aquatic plants.

    Science.gov (United States)

    Reis, A R; Tabei, K; Sakakibara, Y

    2014-01-30

    The purpose of this study was to evaluate experimentally and theoretically the oxidation mechanisms and overall removal rates of phenolic endocrine disrupting chemicals (EDCs) by aquatic plants. EDCs used in this study were bisphenol-A (BPA), 2,4-dichlorophenol (2,4-DCP), 4-tert-octylphenol (4-t-OP), and pentachlorophenol (PCP). Referring to reported detection levels in aquatic environments and contaminated sites, the feed concentration of each EDC was set from 1 to 100μg/L. Experimental results showed that, except for PCP, phenolic EDCs were stably and concurrently removed by different types of aquatic plants over 70 days in long-term continuous treatments. Primal enzymes responsible for oxidation of BPA, 2,4-DCP, and 4-t-OP were peroxidases (POs). Moreover, enzymatic removal rates of BPA, 2,4-DCP, and 4-t-OP by POs were more than 2 orders of magnitude larger than those by aquatic plants. Assuming that overall removal rates of EDCs are controlled by mass transfer rates onto liquid films on the surface of aquatic plants, an electrochemical method based on the limiting current theory was developed to measure the mass transfer rates of EDCs. Because of extremely large removal rates of EDCs by POs, observed removal rates by aquatic plants were in reasonably good agreement with calculated results by a mathematical model developed based on an assumption that mass transfer limitation is a rate-limiting step. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  13. Population genetic structure in six sympatric and widespread aquatic plants inhabiting diverse lake environments in China.

    Science.gov (United States)

    Cao, Qian-Jin; Mei, Fang-Fang; Wang, Ling

    2017-08-01

    Many aquatic plant species are distributed over large areas and diverse environments with populations interconnected by abiotic and biotic mediators. Here, we examined differences and similarities in the population genetic structure of six sympatric and widespread aquatic plant species. We sampled the aquatic species from six Chinese lakes found on plateaus, plains, and different river systems and analyzed them using inter-simple sequence repeat (ISSR) markers. Samples originating from each lake tended to cluster together. Of the six species, only Nymphoides peltata and Myriophyllum spicatum could be divided into plateau and plain groups, once Taihu Lake individuals were excluded. Genetic similarities between populations connected by the Yangtze River were not consistently higher than unconnected populations. Populations from Taihu Lake and/or Weishanhu Lake were distant from other lake populations for all species except Potamogeton lucens . The Taihu and Weishanhu populations clustered for Ceratophyllum demersum and Typha latifolia . Hydrophilous C. demersum had the lowest gene flow ( Nm  = 0.913), whereas the entomophilous Hydrocharis dubia ( Nm  = 2.084) and N. peltata ( Nm  = 2.204) had the highest gene flow. The genetic relationships among distant populations of aquatic plants reflect the comprehensive effects of environmental selection pressure and biotic and abiotic connectivity. Differences in environmental factors between plateau and plain lakes and long distance hydrochory have limited importance on aquatic plant genetic structures. Among multiple evolutionary forces, gene flow mediated by birds may play the most important role in the formation of genetic patterns in the six species examined. For example, the close genetic relationship between Taihu Lake and Weishanhu Lake populations, each in different river systems and with different climates, may be related to the migration routes of birds. Differences in gene flow among the six aquatic plants

  14. Occurrence of antibiotics in water, sediments, aquatic plants, and animals from Baiyangdian Lake in North China.

    Science.gov (United States)

    Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

    2012-11-01

    This study investigated the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides, in the water, sediments, and biota samples from Baiyangdian Lake, China. A total of 132 samples were collected in 2008 and 2010, and laboratory analyses revealed that antibiotics were widely distributed in the lake. Sulfonamides were the dominant antibiotics in the water (0.86-1563 ng L(-1)), while quinolones were prominent in sediments (65.5-1166 μg kg(-1)) and aquatic plants (8.37-6532 μg kg(-1)). Quinolones (17.8-167 μg kg(-1)) and macrolides [from below detection limit (BDL) to 182 μg kg(-1)] were often found in aquatic animals and birds. Salvinia natans exhibited the highest bioaccumulation capability for quinolones among three species of aquatic plants. Geographical differences of antibiotic concentrations were greatly due to anthropogenic activities. Sewage discharged from Baoding City was likely the main source of antibiotics in the lake. Risk assessment of antibiotics on aquatic organisms suggested that algae and aquatic plants might be at risk in surface water, while animals were likely not at risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Effect of aquatic plants upon planktonic and periphytic organisms: a microcosm-based approach

    Directory of Open Access Journals (Sweden)

    Svetlana Kurbatova

    2016-08-01

    Full Text Available Aquatic plants have a major influence upon other aquatic organisms, by altering both water chemistry and spatial structure of the habitat in shallow water bodies. Some of them, such as Stratiotes aloides L., may suppress algal growth. But how aquatic plants would ultimately influence the heterotrophic community and the aquatic ecosystem as a whole is far from clear. Our microcosm-based study demonstrated that even a modest density of S. aloides caused a decline in phytoplankton chlorophyll concentration and periphytic algae abundance, including cyanobacteria, whereas diatoms appeared to be immune to the plant influence. Photosynthetic rate remained unaltered despite decreased chlorophyll concentration. While bacterial counts remained largely unchanged, more bacteria were observed forming microcolonies as well as associating with particulate organic matter. Numbers of periphytic heterotrophic organisms did not differ significantly between the planted and plant-free control microcosms. Zooplankton diversity increased and cladocerans assumed a more prominent position within the microcosms with macrophytes. We assume that the presence of plant’s leads to increased importance of bacteria and protists in the functioning of the food webs. Therefore, decreasing of algal abundance does not involve reducing the number of heterotrophic planktonic and periphytic organisms.

  16. Aquatic food production modules in bioregenerative life support systems based on higher plants

    Science.gov (United States)

    Bluem, V.; Paris, F.

    Most bioregenerative life support systems (BLSS) are based on gravitropic higher plants which exhibit growth and seed generation disturbances in microgravity. Even when used for a lunar or martian base the reduced gravity may induce a decreased productivity in comparison to Earth. Therefore, the implementation of aquatic biomass production modules in higher plant and/or hybrid BLSS may compensate for this and offer, in addition, the possibility to produce animal protein for human nutrition. It was shown on the SLS-89 and SLS-90 space shuttle missions with the C.E.B.A.S.-MINI MODULE that the edible non gravitropic rootless higher aquatic plant Ceratophyllum demeresum exhibits an undisturbed high biomass production rate in space and that the teleost fish species, Xiphophorus helleri, adapts rapidly to space conditions without loss of its normal reproductive functions. Based on these findings a series of ground-based aquatic food production systems were developed which are disposed for utilization in space. These are plant production bioreactors for the species mentioned above and another suitable candidate, the lemnacean (duckweed) species, Wolffia arrhiza. Moreover, combined intensive aquaculture systems with a closed food loop between herbivorous fishes and aquatic and land plants are being developed which may be suitable for integration into a BLSS of higher complexity.

  17. Aquatic Plant Control Research Program. Ecological Assessment of Kirk Pond

    Science.gov (United States)

    1994-03-01

    population at Kirk Pond for the presence of the plant pathogenic fungus, M. terrestris. The microorganism is known to occur naturally in Ala- bama... saprophytes on a wide variety of organic substrates. No potentially significant plant pathogenic spe- cies were noted among the isolates obtained from the M

  18. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  19. Arbuscular mycorrhizal fungi and dark septate fungi in plants associated with aquatic environments

    Directory of Open Access Journals (Sweden)

    Josy Fraccaro de Marins

    Full Text Available ABSTRACT There have been several reports of symbionts in the roots of plants that live in aquatic environments. Arbuscular mycorrhizal fungi (AMF are the most common microsymbionts and possibly recolonized the aquatic environment together with plants; however, their functions and the extent of their benefits are unclear. Furthermore, the presence of other groups of fungi, such as dark septate fungi (DSF, with functions supposedly analogous to those of mycorrhizal fungi, has also been reported. The present work provides a compilation of data regarding the presence of arbuscular mycorrhizae in plants from, or under the influence of, aquatic environments, and co-colonization by AMF and DSF. Forty species of non-vascular plants, ferns, fern allies, and gymnosperms from 15 families, and 659 species of angiosperms from 87 families were investigated. From the first group (non-flowering plants 57 % of the species showed arbuscular mycorrhizal structures in their tissues or roots, whereas among the second group (flowering plants 71% had such structures. Among the mycorrhizal angiosperms, 52 % showed arbuscules in their roots. DSF were found in 1% of non-flowering plants and 5 % of angiosperms. All of these are discussed in this review.

  20. Aquatic and wetland plants of Puerto Rico. I. Pteridophyta

    Directory of Open Access Journals (Sweden)

    Vega Hernández, Efrén

    1999-12-01

    Full Text Available A description of the aquatic and wetland families of Pteridophytes in Puerto Rico is presented herein. Included are brief descriptions of each family, genus and species, and, when appropriate, keys for genera and species accompany the descriptions. The distribution of each species is also documented with maps, as well as with information on some ecological characteristics of each species.Estudio de los helechos acuáticos y palustres de Puerto Rico, con especial atención a las especies asociadas a cuerpos de aguas quietas y pantanos. Se reconocen 8 géneros y 13 especies. Se dan descripciones, claves, notas de sus hábitats y mapas de distribucidn.

  1. Morphological strategies of Cabomba (Cabombaceae, a genus of aquatic plants

    Directory of Open Access Journals (Sweden)

    Carla Teixeira de Lima

    2014-09-01

    Full Text Available This paper describes the vegetative and reproductive morphology of Cabombaceae species in Brazil, discussing its strategies for survival in an aquatic habitat. Through studies in the field, in cultivation and in the herbarium, we examined the following species: Cabomba aquatica, C. caroliniana, C. furcata and C. haynesii. In cultivation, only C. aquatica, C. furcata and C. haynesii produced flowers. In those three species, the flowers opened during the day on two consecutive days, submerging during the night, although the stigmata of the first two were receptive only on the first day, their anthers dehiscing on the following day. The flowers of C. haynesii remained unreceptive on the first day of anthesis, the stigmata and anthers maturing only on the second day, at different times. Fruit developed when the flowers were submerged. The data provided here are useful for the identification of these species, as well as laying the groundwork for future taxonomic and ecological studies.

  2. Surprising spectra of root-associated fungi in submerged aquatic plants.

    Science.gov (United States)

    Kohout, Petr; Sýkorová, Zuzana; Ctvrtlíková, Martina; Rydlová, Jana; Suda, Jan; Vohník, Martin; Sudová, Radka

    2012-04-01

    Similarly to plants from terrestrial ecosystems, aquatic species harbour wide spectra of root-associated fungi (RAF). However, comparably less is known about fungal diversity in submerged roots. We assessed the incidence and diversity of RAF in submerged aquatic plants using microscopy, culture-dependent and culture-independent techniques. We studied RAF of five submerged isoetid species collected in four oligotrophic freshwater lakes in Norway. Levels of dark septate endophytes (DSE) colonization differed among the lakes and were positively related to the organic matter content and negatively related to pH. In total, we identified 41 fungal OTUs using culture-dependent and culture-independent techniques, belonging to Mucoromycotina, Chytridiomycota, Glomeromycota, Ascomycota as well as Basidiomycota. Sequences corresponding to aquatic hyphomycetes (e.g. Nectria lugdunensis, Tetracladium furcatum and Varicosporium elodeae) were obtained. Eight arbuscular mycorrhizal taxa belonging to the orders Archaeosporales, Diversisporales and Glomerales were also detected. However, the vast majority of the fungal species detected (e.g. Ceratobasidium sp., Cryptosporiopsis rhizophila, Leptodontidium orchidicola, and Tuber sp.) have previously been known only from roots of terrestrial plants. The abundance and phylogenetic distribution of mycorrhizal as well as nonmycorrhizal fungi in the roots of submerged plants have reshaped our views on the fungal diversity in aquatic environment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Potential for biotic resistance from herbivores to tropical and subtropical plant invasions in aquatic ecosystems

    NARCIS (Netherlands)

    Petruzella, A.; Grutters, B.M.C.; Thomaz, S.M.; Bakker, E.S.

    2017-01-01

    Invasions of tropical and subtropical aquatic plants threaten biodiversity and cause ecological and economic impacts worldwide. An urgent question is whether native herbivores are able to inhibit the spread of these alien species thus providing biotic resistance. The potential for biotic resistance

  4. Native aquatic plants and ecological condition of southwestern wetlands and riparian areas

    Science.gov (United States)

    Alvin L. Medina

    1996-01-01

    The determination of the ecological condition of wetland and riparian habitats has been the focus of research by many scientists, because of the importance to understand the processes and related functions of these systems. Research on montane wetland and riparian systems has shown the relative importance of native aquatic plants in maintaining these systems in a...

  5. Management and control methods of invasive alien freshwater aquatic plants: a review

    NARCIS (Netherlands)

    Hussner, Andreas; Stiers, I.; Verhofstad, M.J.J.M.; Bakker, E.S.; Grutters, B.M.C.; Haury, J.; van Valkenburg, J.L.C.H.; Brundu, G.; Newman, J.; Clayton, J.S.; Anderson, L.W.J.; Hofstra, D.

    2017-01-01

    Introduced invasive alien aquatic plants (IAAPs) threaten ecosystems due to their excessive growth and have both ecological and economic impacts. To minimize these impacts, effective management of IAAPs is required according to national or international laws and regulations (e.g. the new EU

  6. Aquatic effect and risk assessment for plant protection products : evaluation of the Dutch 2011 proposal

    NARCIS (Netherlands)

    Smit, C.E.; Arts, G.H.P.; Brock, T.C.M.; Hulscher, ten T.E.M.; Luttik, R.; Vliet, van P.J.M.

    2013-01-01

    In this report the proposals for the prospective (underlying Regulation 1107/2009/EC) and the retrospective (underlying the Water Framework Directive) aquatic effect assessment for plant protection products (pesticides) as described in Alterra Report 2235 are evaluated by applying the proposed

  7. Carbon isotope variability in monosaccharides and lipids of aquatic algae and terrestrial plants

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Dongen, B.E. van; Schouten, S.

    2002-01-01

    The stable carbon-isotope compositions of individual monosaccharides and lipids, as well as the bulk stable carbon-isotope composition of total cell material from different aquatic and terrestrial plants were determined. With the exception of a Phaeocystis sp. bloom sample, monosaccharides were

  8. Herbicide risk assessment for non-target aquatic plants: sulfosulfuron--a case study.

    Science.gov (United States)

    Davies, Joanna; Honegger, Joy L; Tencalla, Francesca G; Meregalli, Giovanna; Brain, Philip; Newman, Jonathan R; Pitchford, Hannah F

    2003-02-01

    Herbicides entering the aquatic environment by spray drift, run-off and leaching to field drains may cause adverse effects on non-target aquatic vegetation. The potential for such effects has typically been evaluated from tests with floating, monocotyledonous Lemna sp. However, concern has been expressed as to whether this species could be used to indicate potential effects on other vegetation types, particularly rooted, submerged, emergent or dicotyledonous species. In 1997, the Centre for Aquatic Plant Management undertook development of new tests based on the additional species, Glyceria maxima (Hartm) Holmb, Lagarosiphon major (Ridl) Moss and Myriophyllum spicatum L. The resulting methodology was used to assess the effects of the sulfonylurea herbicide, sulfosulfuron on these species. Data presented here demonstrate that exposure to initial sulfosulfuron concentrations of 3.33 microg litre(-1) for up to 21 days was tolerated by these species and that adverse effects were observed only when plants were exposed to initial concentrations of 3.33 and 10 microg litre(-1) for 70 days. As the occurrence of such high initial concentrations for long periods is unlikely in the aquatic environment, sulfosulfuron is not expected to have adverse effects on the growth of these species. This study has also demonstrated that G maxima, L major and M spicatum grown in small outdoor tanks can be used successfully to assess the effects of crop-protection products on non-target aquatic flora.

  9. Influence of nonylphenol on the fatty acids and hydrocarbon composition of aquatic plants

    Directory of Open Access Journals (Sweden)

    І. О. Osinna

    2009-11-01

    Full Text Available Composition of surface lipids of aquatic plants Acorus calamus L., Typha latifolia L. and Carex acuta L. was investigated under the influence of nonylphenol strong solution. Experimental plants showed some significant changes in the surface lipids composition in comparison with a control. Change in the fatty acids composition, decrease of hydrocarbons content and biosynthetical disorder in the elongation processes of some certain components were revealed.

  10. The Antibiotic Activity Of Some Aquatic Plants And Algal Extracts From Jordan

    OpenAIRE

    Mesmar, M. N. [محمد نزار مسمار; Abussaud, M.

    1991-01-01

    The antimicrobial activity of the extracts of three fresh water green algae, four marine green algae, two brown marine algae and five red marine algae from the Jordanian part of the Aqaba Gulf, together with four aquatic higher plants were screened against E. coli and Staphylococcus aureus. The inhibition zones were observed and measured from the margin of the well containing the plant extract to the beginning of the bacterial growth on nutrient agar plates. The fresh water algae extracts ...

  11. Aquatic Plant Control Research Program. Microbiological Control of Eurasian Watermilfoil.

    Science.gov (United States)

    1983-06-01

    Charudattan (1975) has reported on, among others, intensive studies with Rhizoctonia solani Kuehn as a pathogen of waterhyacinth as well as work with Pythium...rhizosphere has been used for plant protection rather than plant destruction. Koths and Gunner (1967) induced chitinase activity against Fusarium ...of the carnations protected against Fusarium attack. The rationale for this treatment was that the original isolate, endemic to the rhizo- sphere

  12. Benefits of flooding-induced aquatic adventitious roots depend on the duration of submergence: linking plant performance to root functioning.

    Science.gov (United States)

    Zhang, Qian; Huber, Heidrun; Beljaars, Simone J M; Birnbaum, Diana; de Best, Sander; de Kroon, Hans; Visser, Eric J W

    2017-07-01

    Temporal flooding is a common environmental stress for terrestrial plants. Aquatic adventitious roots (aquatic roots) are commonly formed in flooding-tolerant plant species and are generally assumed to be beneficial for plant growth by supporting water and nutrient uptake during partial flooding. However, the actual contribution of these roots to plant performance under flooding has hardly been quantified. As the investment into aquatic root development in terms of carbohydrates may be costly, these costs may - depending on the specific environmental conditions - offset the beneficial effects of aquatic roots. This study tested the hypothesis that the balance between potential costs and benefits depends on the duration of flooding, as the benefits are expected to outweigh the costs in long-term but not in short-term flooding. The contribution of aquatic roots to plant performance was tested in Solanum dulcamara during 1-4 weeks of partial submergence and by experimentally manipulating root production. Nutrient uptake by aquatic roots, transpiration and photosynthesis were measured in plants differing in aquatic root development to assess the specific function of these roots. As predicted, flooded plants benefited from the presence of aquatic roots. The results showed that this was probably due to the contribution of roots to resource uptake. However, these beneficial effects were only present in long-term but not in short-term flooding. This relationship could be explained by the correlation between nutrient uptake and the flooding duration-dependent size of the aquatic root system. The results indicate that aquatic root formation is likely to be selected for in habitats characterized by long-term flooding. This study also revealed only limited costs associated with adventitious root formation, which may explain the maintenance of the ability to produce aquatic roots in habitats characterized by very rare or short flooding events.

  13. Weed risk assessment for aquatic plants: modification of a New Zealand system for the United States.

    Science.gov (United States)

    Gordon, Doria R; Gantz, Crysta A; Jerde, Christopher L; Chadderton, W Lindsay; Keller, Reuben P; Champion, Paul D

    2012-01-01

    We tested the accuracy of an invasive aquatic plant risk assessment system in the United States that we modified from a system originally developed by New Zealand's Biosecurity Program. The US system is comprised of 38 questions that address biological, historical, and environmental tolerance traits. Values associated with each response are summed to produce a total score for each species that indicates its risk of invasion. To calibrate and test this risk assessment, we identified 39 aquatic plant species that are major invaders in the continental US, 31 species that have naturalized but have no documented impacts (minor invaders), and 60 that have been introduced but have not established. These species represent 55 families and span all aquatic plant growth forms. We found sufficient information to assess all but three of these species. When the results are compared to the known invasiveness of the species, major invaders are distinguished from minor and non-invaders with 91% accuracy. Using this approach, the US aquatic weed risk assessment correctly identifies major invaders 85%, and non-invaders 98%, of the time. Model validation using an additional 10 non-invaders and 10 invaders resulted in 100% accuracy for the former, and 80% accuracy for the latter group. Accuracy was further improved to an average of 91% for all groups when the 17% of species with scores of 31-39 required further evaluation prior to risk classification. The high accuracy with which we can distinguish non-invaders from harmful invaders suggests that this tool provides a feasible, pro-active system for pre-import screening of aquatic plants in the US, and may have additional utility for prioritizing management efforts of established species.

  14. Weed risk assessment for aquatic plants: modification of a New Zealand system for the United States.

    Directory of Open Access Journals (Sweden)

    Doria R Gordon

    Full Text Available We tested the accuracy of an invasive aquatic plant risk assessment system in the United States that we modified from a system originally developed by New Zealand's Biosecurity Program. The US system is comprised of 38 questions that address biological, historical, and environmental tolerance traits. Values associated with each response are summed to produce a total score for each species that indicates its risk of invasion. To calibrate and test this risk assessment, we identified 39 aquatic plant species that are major invaders in the continental US, 31 species that have naturalized but have no documented impacts (minor invaders, and 60 that have been introduced but have not established. These species represent 55 families and span all aquatic plant growth forms. We found sufficient information to assess all but three of these species. When the results are compared to the known invasiveness of the species, major invaders are distinguished from minor and non-invaders with 91% accuracy. Using this approach, the US aquatic weed risk assessment correctly identifies major invaders 85%, and non-invaders 98%, of the time. Model validation using an additional 10 non-invaders and 10 invaders resulted in 100% accuracy for the former, and 80% accuracy for the latter group. Accuracy was further improved to an average of 91% for all groups when the 17% of species with scores of 31-39 required further evaluation prior to risk classification. The high accuracy with which we can distinguish non-invaders from harmful invaders suggests that this tool provides a feasible, pro-active system for pre-import screening of aquatic plants in the US, and may have additional utility for prioritizing management efforts of established species.

  15. SeagrassDB: An open-source transcriptomics landscape for phylogenetically profiled seagrasses and aquatic plants.

    Science.gov (United States)

    Sablok, Gaurav; Hayward, Regan J; Davey, Peter A; Santos, Rosiane P; Schliep, Martin; Larkum, Anthony; Pernice, Mathieu; Dolferus, Rudy; Ralph, Peter J

    2018-02-09

    Seagrasses and aquatic plants are important clades of higher plants, significant for carbon sequestration and marine ecological restoration. They are valuable in the sense that they allow us to understand how plants have developed traits to adapt to high salinity and photosynthetically challenged environments. Here, we present a large-scale phylogenetically profiled transcriptomics repository covering seagrasses and aquatic plants. SeagrassDB encompasses a total of 1,052,262 unigenes with a minimum and maximum contig length of 8,831 bp and 16,705 bp respectively. SeagrassDB provides access to 34,455 transcription factors, 470,568 PFAM domains, 382,528 prosite models and 482,121 InterPro domains across 9 species. SeagrassDB allows for the comparative gene mining using BLAST-based approaches and subsequent unigenes sequence retrieval with associated features such as expression (FPKM values), gene ontologies, functional assignments, family level classification, Interpro domains, KEGG orthology (KO), transcription factors and prosite information. SeagrassDB is available to the scientific community for exploring the functional genic landscape of seagrass and aquatic plants at: http://115.146.91.129/index.php .

  16. Accumulation of uranium by aquatic plants in field conditions: prospects for phytoremediation.

    Science.gov (United States)

    Favas, Paulo J C; Pratas, João; Varun, Mayank; D'Souza, Rohan; Paul, Manoj S

    2014-02-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n=200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1,217 μg L(-1). The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4,979 mg kg(-1)) followed by Callitriche stagnalis (1963mgkg(-1)), Callitriche hamulata (379 mg kg(-1)), Ranunculus peltatus subsp. saniculifolius (243 mg kg(-1)), Callitriche lusitanica (218 mg kg(-1)), and Ranunculus trichophyllus (65.8 mg kg(-1)). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg(-1)). Among the free-floating species, the highest U content (42.5 mg kg(-1)) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. © 2013.

  17. The aquatic vascular plant Ruppia maritima as an indicator organism for contaminated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Tagliabue, M.D.; Thursby, G.B.; Walker, H.A. [Environmental Protection Agency, Narragansett, RI (United States); Johnston, R.K.

    1995-12-31

    An ongoing estuarine ecological risk assessment case study for the Portsmouth Naval Shipyard in the Great Bay Estuary (New Hampshire, Maine) was the catalyst to continue development a rooted aquatic plant sediment toxicity test. Laboratory studies were conducted to evaluate effects of lead, the primary site contaminant on R. maritima in the Great Bay. Although the aquatic vascular plant Zostra marina comprises up to 46% of the Great Bay subtidal habitat, R. maritima`s much smaller size makes it a more practical laboratory organism. Effects on Ruppia may offer useful insights into potential effects on Zostra or other aquatic vascular plants. Presently rooted vascular plants are not found in Clark Cove located adjacent to a landfill disposal site on the shipyard. The absence of rooted vegetation can be contributed to, physical parameters of the site (turbidity, grain size, texture) or chemical parameters (heavy metal/Pb contamination, redox potential). Exposure of bedded and nonbedded plants occurred over a four day and ten day period using lead sulfate. Concentrations for bedded exposures were as follows, 0.3, 0.5, 0.8, 1.0 simultaneously extracted metal/acid volatile sulfide (SEM/AVS) molar ratios, and 0.1, 1.0, 10.0 and 100.0mg/l Pb for water only exposures. Reduction in cumulative leaf growth was observed for the Clark Cove sediments as well as the spiked sediments as compared to reference sediments.

  18. ZINC AND LEAD IN BOTTOM SEDIMENTS AND AQUATIC PLANTS IN RIVER NAREW

    Directory of Open Access Journals (Sweden)

    Elżbieta Skorbiłowicz

    2014-12-01

    Full Text Available Aquatic ecosystems are a valuable part of natural environment. The increasing level of pollution in waters transforming biocoenoses and other adverse effects of the impact of toxic substances have contributed to the development of biological monitoring. The aim of the study was to determine the changes in contents of zinc and lead in bottom sediments and roots of aquatic plants: Phragmites australis and Acorus calamus in the river Narew. There were 14 points on the river, from where samples of bottom sediments and plant material were collected. The contents of lead and zinc were determined by means of flame atomic absorption spectrophotometry using Varian device. It was proven that bottom sediments were characterized by low contents of zinc and lead except from two sampling points: in Bondary and Narew. Achieved results of analyzes of plant material showed a slight exceeding in the case of lead. Spatial distribution of zinc and lead contents in examined roots of plants coincided with their contents in bottom sediments, which was also confirmed by statistical analysis. It was proven that aquatic plants had greater tendency for accumulation of metals than bottom sediments.

  19. Avoidance and tolerance to avian herbivores in aquatic plants

    NARCIS (Netherlands)

    Hidding, A.

    2009-01-01

    Tolerance and avoidance are the two contrasting strategies that plants may adopt to cope with herbivores. Tolerance traits define the degree to which communities remain unaffected by herbivory. Trade-offs between herbivore avoidance and competitive strength and between avoidance and colonization

  20. Aquatic indicator organisms as a tool to monitor discharges from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Outola, Iisa; Vartti, Vesa-Pekka; Klemola, Seppo [STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland)

    2014-07-01

    There are four operating nuclear power plant units in Finland at two separate locations. The units started operation during 1977-1980. The surveillance of radioactive substances in the vicinities of the nuclear power plant is carried out under the permanent monitoring programs. Some 1000 samples are taken annually from the surroundings of the power plants to confirm that the discharges from the power plants are within permissible release limits and to monitor the dispersion of discharges in the environment. Aquatic indicator organisms (macro-algae, periphyton, mussels, crustacean, submerged aquatic plants) are included in the monitoring program. The indicator organisms are valuable monitoring objects both in normal and emergency situations because they accumulate effectively and often very rapidly radioactive substances from the medium. Six different species (Periphyton, Fucus vesiculosus, Myriophyllum spicatum, Potamogeton pectinatus, Saduria entomon, Macoma Baltica/Mytilus edulis) are collected regularly. Number of sampling location for each species varies from 1 to 7. Some species are collected continuously, some 1-2 times in a year. In this study we have evaluated the monitoring results for the aquatic indicator organisms for the period of 2005-2010 concerning concentration of discharge nuclides. Our aim was to answer the following questions using the monitoring data from aquatic organisms: 1) Which radionuclides are released to the marine environment and how often do we detect them? 2) How far from the nuclear power plants discharge radionuclides are detected? 3) How concentration of discharge radionuclides has changed with time in aquatic organisms? The number of discharge nuclides detected in the aquatic indicator samples was 11. Most of them were only detected in few samples, but {sup 58}Co, {sup 60}Co, {sup 54}Mn and {sup 110m}Ag were detected more frequently. Most of the observations above detection limits were made within the 5 km distance from the

  1. Mapping of the aquatic plants infestation in reservoirs using multiscale image and artificial neural networks

    Directory of Open Access Journals (Sweden)

    Narjara C. da Cruz

    2005-08-01

    Full Text Available In past few years, infestations of aquatic plants in reservoirs have been studied as an effect of the environmental unbalance caused by pollution and damming of rivers. The excessive amount of plants, deriving from this unbalance, makes navigation and the production of electricity difficult. This kind of occurrence, as well as the appearance of some substances in the water, cause changes in the water radiance detected by satellite sensors. Thus, processing techniques of remote sensing and data analysis may be used as a complementary data source to give information related to the degree of infestation of these plants in reservoirs. So, this research aimed at verifying the influence of the spatial resolution of multispectral images in the detection and mapping of areas infested by aquatic plants in a small reservoir, using multiscale analysis procedures and supervised classification by artificial neural networks. Multispectral images IKONOS of the Salto Grande reservoir, in the city of Americana-SP were used. At first, a multiscale image was generated, resulting in images of 8, 16 and 32 meters of spatial resolution. In the classification of these images, the input data for artificial neural networks was constituted of multispectral images IKONOS, texture data, and a vegetation index image and allowed represent the spectral variations of the water body and infested areas of aquatic plants in the various levels of spatial resolution. Furthermore, an analysis was made comparing classified multiscale images by using cross tabulation, which permits comparing the results obtained in the multiscale levels. As result is pointed out that the thematic maps were representative for the 4 levels of spatial resolution. The method used was adequate to map the spectral variation of the water body and to detect infested areas of aquatic plants in the various levels of resolution of the image. The classification by neural network using parameters defined for the

  2. A Study on Effect of Water Background on Canopy Spectral of Wetland Aquatic Plant.

    Science.gov (United States)

    Liu, Guang; Tang, Peng; Cai Zhan-qing; Wang, Tian-tian; Xu, Jun-feng

    2015-10-01

    Aquatic vegetation is the core of the wetland ecosystem, and it's also the main factor influencing the wetland ecosystem functions. In recent years, satellite remote sensing technology has been widely used in the investigation, classification and protection fields of wetland vegetation resources. Because of its unique growth environment, aquatic vegetation, the canopy spectrum of aquatic vegetation will be affected by water background elements including air-water interface, plankton in the water, sediment content, transparency, water depth, sediment, and the other optically active ingredients. When the remote sensing technology for wetland aquatic vegetation canopy spectral studies, should be considered the growth environment differences between aquatic and terrestrial vegetation. However, previous studies did not get the attention it deserves. This paper choose a typical water plant (Iris tentorium Maxim) as the research object, simulate the growth environment of wetland aquatic plants, use the feature spectrometer measurements the spectral reflectance of Iris tentorium Maxim vegetation canopy under different water depth gradient background (400-2 400 nm). Experimental results show that there is a significant negative correlation between background water depth and Iris canopy reflectance. Visible light band absolute correlation coefficient is above 0.9, near infrared band absolute correlation coefficient is above 0.8. In visible light and near infrared band, with water depth increases, the Iris canopy reflectance decreases obviously. Finally based on the highest correlation band of visible light and near infrared region (505, 717, 1 075 and 2 383 nm) established the linear equation between background water depth and the canopy reflectance, obtained the related parameters.

  3. Aquatic Field Survey at Volunteer Army Ammunition Plant, Chattanooga, Tennessee

    Science.gov (United States)

    1977-06-24

    10 feet for all three bays. Stormwater runoff from residential areas and VAAP enter Waconda Bay. The watershed of Reference Bay A is largely...and Lake City Ammunition Plant, near Kansas City , Missouri) reported observable effects of munitions waste discharges on the periphyton community...vegetationsfarbungen in Bachen. Biologia gen. 3: 791-814. Harrison, F.W. 1974. Sponges (Porifera: Spongillidae). In: C.W. Hart and S.L.H. Fuller (eds

  4. The Mitochondrial Genome of an Aquatic Plant, Spirodela polyrhiza

    OpenAIRE

    Wang, Wenqin; Wu, Yongrui; Messing, Joachim

    2012-01-01

    BACKGROUND: Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt) genome could provide clues for the understanding of the evolution of mt genomes in plant. METHODS: Spirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitiv...

  5. The effect of radioactive contamination of the Yenisei river on cytogenetic characteristics of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, A.; Medvedeva, M. [Institute of Biophysics SB Russian Academy of Sciences (Russian Federation); Muratova, E. [Institute of Forest SB Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for many years. Aquatic plants are an important component of water ecosystems, which can accumulate high levels of radionuclides and, thus, can be used in bio-monitoring and bioremediation. The purpose of the study was to assess levels of radionuclides and to evaluate the frequency of chromosomal aberrations in samples of submerged plants collected in different parts of the Yenisei River. The following species were studied: Fontinalis antipyretica, Batrachium kauffmanii, Myriophyllum spicatum, Elodea canadensis, Ceratophyllum demersum and various Potamogeton species. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 330 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2003-2012. Detailed analysis of radioactive contamination of aquatic plants of the Yenisei River revealed large-scale contamination of aquatic plants as far as 250 km downstream of the MCC. Before the last MCC reactor was shut down in 2010, about 30 radionuclides, including uranium and transuranium elements, were detected in the biomass of aquatic plants. The highest concentration factors of the major radionuclides were obtained for Fontinalis antipyretica and Potamogeton lucens. Samples of the plants collected after the shutdown of the reactor contained considerably lower activity levels of artificial radionuclides, and their diversity was significantly decreased. Results of cytogenetic investigations of aquatic plants collected when the reactor was still operating (2003-2009) suggest that at the MCC discharge site and downstream the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of the plants was considerably higher (up to 30%) than in the control

  6. A new mechanism of macrophyte mitigation: how submerged plants reduce malathion's acute toxicity to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2014-08-01

    A growing body of evidence suggests that aquatic plants can mitigate the toxicity of insecticides to sensitive aquatic animals. The current paradigm is that this ability is driven primarily by insecticide sorption to plant tissues, especially for hydrophobic compounds. However, recent work shows that submerged plants can strongly mitigate the toxicity of the relatively hydrophilic insecticide malathion, despite the fact that this compound exhibits a slow sorption rate to plants. To examine this disparity, we tested the hypothesis that the mitigating effect of submerged plants on malathion's toxicity is driven primarily by the increased water pH from plant photosynthesis causing the hydrolysis of malathion, rather than by sorption. To do this, we compared zooplankton (Daphnia magna) survival across five environmentally relevant malathion concentrations (0, 1, 4, 6, or 36 μg L(-1)) in test containers where we chemically manipulated water pH in the absence of plants or added the submerged plant (Elodea canadensis) but manipulated plant photosynthetic activity via shading or no shading. We discovered that malathion was equally lethal to Daphnia at all concentrations tested when photosynthetically inactive (i.e. shaded) plants were present (pH at time of dosing=7.8) or when pH was chemically decreased (pH=7.7). In contrast, when photosynthetically active (i.e. unshaded) plants were present (pH=9.8) or when pH was chemically increased (pH=9.5), the effects of 4 and 6 μg L(-1) of malathion on Daphnia were mitigated strongly and to an equal degree. These results demonstrate that the mitigating effect of submerged plants on malathion's toxicity can be explained entirely by a mechanism of photosynthesizing plants causing an increase in water pH, resulting in rapid malathion hydrolysis. Our findings suggest that current ecotoxicological models and phytoremediation strategies may be overlooking a critical mechanism for mitigating pesticides. Copyright © 2014 Elsevier Ltd

  7. Laboratory evaluation of Ethiopian local plant Phytolacca dodecandra extract for its toxicity effectiveness against aquatic macroinvertebrates.

    Science.gov (United States)

    Karunamoorthi, K; Bishaw, D; Mulat, T

    2008-01-01

    In this study, we evaluated the toxicity effectiveness of berries crude extract of Endod [vernacular name (local native language, Amharic); Phytolacca dodecandra] against aquatic macroinvertebrates Baetidae (Mayflies) and Hydropsychidae (Caddisflies), under laboratory conditions. In Ethiopia, toxic plant, berries of Phytolacca dodecandra are being commonly used for washing clothes and to control fresh water snails. Macroinvertebrates are useful biological indicators of change in the aquatic ecosystems. The present study clearly revealed that the LC50 and LC90 values for berries crude extract of Phytolacca dodecandra against Baetidae were 181.94 and 525.78 mg/l and lethal doses (LC50 and LC90) required for Hydropsychidae were 1060.69 and 4120.4 mg/l respectively. The present investigation demonstrated that Baetidae was more susceptible than Hydropsychidae, even at shorter exposure period of 2 h. From our preliminary investigation the toxicity effectiveness of crude extracts of Phytolacca dodecandra has been clearly shown. In addition, it requires further explorations which address both the toxicity activity and the active principles that are responsible for its toxicity effectiveness. Ultimately, the release/introduction of Phytolacca dodecandra plant berries extracts into the river/streams leads to disruption of food chain in the aquatic ecosystem. Therefore, at this moment preserving the aquatic ecosystem is extremely essential and inevitable.

  8. Topical report on sources and systems for aquatic plant biomass as an energy resource

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.; Ryther, J.H.; Waaland, R.; Wilson, E.H.

    1977-10-21

    Background information is documented on the mass cultivation of aquatic plants and systems design that is available from the literature and through consultation with active research scientists and engineers. The biology of microalgae, macroalgae, and aquatic angiosperms is discussed in terms of morphology, life history, mode of existence, and ecological significance, as they relate to cultivation. The requirements for growth of these plants, which are outlined in the test, suggest that productivity rates are dependent primarily on the availability of light and nutrients. It is concluded that the systems should be run with an excess of nutrients and with light as the limiting factor. A historical review of the mass cultivation of aquatic plants describes the techniques used in commercial large-scale operations throughout the world and recent small-scale research efforts. This review presents information on the biomass yields that have been attained to date in various geographical locations with different plant species and culture conditions, emphasizing the contrast between high yields in small-scale operations and lower yields in large-scale operations.

  9. Potential of some aquatic plants for removal of arsenic from wastewater by green technology

    Directory of Open Access Journals (Sweden)

    Mohammed Barznji Dana A.

    2015-03-01

    Full Text Available Phytoremediation or green technology is counted among the successful and effective biological contaminated water treatment techniques. Basically, the concept of this green, cost-effective, simple, environmentally nondisruptive method consists in using plants and microbiological processes to reduce contaminants in the ecosystem. Different species from aquatic plants (emerged, free-floating, and submerged have been studied to mitigate toxic contaminants such as arsenic, cadmium, chromium, copper, lead, mercury, zinc, etc. Arsenic is one of the most severe toxic elements; it is widely distributed in the environment, usually found in combination with chloride, oxygen, sulphur and metal ions as a result of mineral dissolution from sedimentary or volcanic rocks and the dilution of geothermal water. The effluents from both industrial and agricultural sectors are also regarded as sources to contaminate water. From the accumulation point of view, several aquatic plants have been mentioned as good arsenic accumulators and their performance is evaluated using the green technology method. These include Spirodela polyrhiza, Wolffia globosa, Lemna gibba, L. minor, Eichhornia crassipes, Azolla caroliniana, Azolla filiculoides, Azolla pinnata, Ceratophyllum demersum and Pistia stratiotes. The up-to-date information illustrated in this review paper generates knowledge about the ability of some common aquatic plants around the globe to remediate arsenic from contaminated water.

  10. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  11. Cascading effects of induced terrestrial plant defences on aquatic and terrestrial ecosystem function.

    Science.gov (United States)

    Jackrel, Sara L; Wootton, J Timothy

    2015-04-22

    Herbivores induce plants to undergo diverse processes that minimize costs to the plant, such as producing defences to deter herbivory or reallocating limited resources to inaccessible portions of the plant. Yet most plant tissue is consumed by decomposers, not herbivores, and these defensive processes aimed to deter herbivores may alter plant tissue even after detachment from the plant. All consumers value nutrients, but plants also require these nutrients for primary functions and defensive processes. We experimentally simulated herbivory with and without nutrient additions on red alder (Alnus rubra), which supplies the majority of leaf litter for many rivers in western North America. Simulated herbivory induced a defence response with cascading effects: terrestrial herbivores and aquatic decomposers fed less on leaves from stressed trees. This effect was context dependent: leaves from fertilized-only trees decomposed most rapidly while leaves from fertilized trees receiving the herbivory treatment decomposed least, suggesting plants funnelled a nutritionally valuable resource into enhanced defence. One component of the defence response was a decrease in leaf nitrogen leading to elevated carbon : nitrogen. Aquatic decomposers prefer leaves naturally low in C : N and this altered nutrient profile largely explains the lower rate of aquatic decomposition. Furthermore, terrestrial soil decomposers were unaffected by either treatment but did show a preference for local and nitrogen-rich leaves. Our study illustrates the ecological implications of terrestrial herbivory and these findings demonstrate that the effects of selection caused by terrestrial herbivory in one ecosystem can indirectly shape the structure of other ecosystems through ecological fluxes across boundaries. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  12. Two-flow simulation of the natural light field within a canopy of submerged aquatic plants

    Science.gov (United States)

    Ackleson, S. G.; Klemas, V.

    1986-01-01

    A two-flow model is developed to simulate a light field composed of both collimated and diffuse irradiance within natural waters containing a canopy of bottom-adhering plants. To account for the effects of submerging a canopy, the transmittance and reflectance terms associated with each plant structure (leaves, stems, fruiting bodies, etc.) are expressed as functions of the ratio of the refractive index of the plant material to the refractive index of the surrounding media and the internal transmittance of the plant stucture. Algebraic solutions to the model are shown to yield plausible physical explanations for unanticipated variations in volume reflectance spectra. The effect of bottom reflectance on the near-bottom light field is also investigated. These indicate that within light-limited submerged aquatic plant canopies, substrate reflectance may play an important role in determining the amount of light available to the plants and, therefore, canopy productivity.

  13. Uptake of uranium by native aquatic plants: potential for bioindication and phytoremediation

    Directory of Open Access Journals (Sweden)

    Favas P. J. C.

    2013-04-01

    Full Text Available The work presented here is a part the on going study on the uraniferous geochemical province of Central Portugal in which, the use of aquatic plants as indicators of uranium contamination is being probed using aquatic plants emphasizing their potential use in the emerging phytotechnologies. Even though we have observed very low concentration of U in the fresh waters of the studied sites we found a set of vegetable species with the ability to accumulate U in concentrations which are orders of magnitude higher than the surrounding environment. We have observed that Apium nodiflorum, Callitriche stagnalis, Lemna minor and Fontinalis antipyretica accumulated significant amounts of uranium, whereas Oenanthe crocata excluded U. These results indicate substantial scope for proper radiophytoremediation and phytosociological investigation exploiting the native flora. These species show great potential for phytoremediation because they are endemic and easy to grow in their native conditions. A. nodiflorum and C. stagnalis have high bioproductivity and yield good biomass.

  14. Utilization of emergent aquatic plants for biomass-energy-systems development

    Energy Technology Data Exchange (ETDEWEB)

    Kresovich, S.; Wagner, C.K.; Scantland, D.A.; Groet, S.S.; Lawhon, W.T.

    1982-02-01

    A review was conducted of the available literature pertaining to the following aspects of emergent aquatic biomass: identification of prospective emergent plant species for management; evaluation of prospects for genetic manipulation; evaluation of biological and environmental tolerances; examination of current production technologies; determination of availability of seeds and/or other propagules, and projections for probable end-uses and products. Species identified as potential candidates for production in biomass systems include Arundo donax, Cyperus papyrus, Phragmites communis, Saccharum spontaneum, Spartina alterniflora, and Typha latifolia. If these species are to be viable candidates in biomass systems, a number of research areas must be further investigated. Points such as development of baseline yield data for managed systems, harvesting conceptualization, genetic (crop) improvement, and identification of secondary plant products require refinement. However, the potential pay-off for developing emergent aquatic systems will be significant if development is successful.

  15. International Symposium on the Biology and Management of Aquatic Plants. Volume 31

    Science.gov (United States)

    1993-01-01

    in potting soil beetle (Epicauta spp.) that causes burning and blistering of (Metro-mix 200) in a growth chamber under the following the skin (3...acids, and even burned with propane torches. These early experiences led to the development of the current national, state, and local aquatic plant...most suitable species, but tilapia Asia. Lake Rawa Pening in Java, Indonesia, is large but very (T. rendalli) and tawes (Puntius gonionotus) have also

  16. Chromium accumulation in submerged aquatic plants treated with tannery effluent at Kanpur, India.

    Science.gov (United States)

    Gupta, Kiran; Gaumat, Sumati; Mishra, Kumkum

    2011-09-01

    Aquatic macrophytes have been widely studied because of their capability of absorbing contaminants from water and their subsequent use in biomonitoring. This study presents a comparison of Cr accumulating potential of submerged aquatic plants viz Vallisneria spiralis and Hydrilla verticillata. These plants were treated with various concentrations of treated tannery effluent collected from UASB, Jajmau, Kanpur under repeated exposure in controlled laboratory conditions in order to assess their maximum bioaccumulation potential. The maximum accumulation of 385.6 and 201.6 microg g(-1) dry weight was found in roots of V. spiralis and the whole plants of H. verticillata, respectively at 100% concentration after 9th day of effluent exposure. The chlorophyll and protein content of both species decreased with increase in effluent concentration and duration. At highest concentration and duration a maximum reduction of 67.4 and 62.66% in total chlorophyll content, 9.97 and 4.66% in carotenoid content and 62.66 and 59.36% in protein content was found in V. spiralis and H. verticillata respectively. Anatomical studies in both V. spiralis and H. verticillata was carried out to assess the effects of metal accumulation within the plants. Changes in the anatomical structures of both plants exhibits the capacity of these species to act as indicator of effluent toxicity. The high accumulation potential of Cr by both plants revealed their capability to remove pollutants from effluent.

  17. Effect of arsenic on reflectance spectra and chlorophyll fluorescence of aquatic plants.

    Science.gov (United States)

    Iriel, Analia; Dundas, Gavin; Fernández Cirelli, Alicia; Lagorio, Maria G

    2015-01-01

    Arsenic pollution of groundwater is a serious problem in many regions of Latin America that causes severe risks to human health. As a consequence, non-destructive monitoring methodologies, sensitive to arsenic presence in the environment and able to perform a rapid screening of large polluted areas, are highly sought-after. Both chlorophyll - a fluorescence and reflectance of aquatic plants may be potential indicators to sense toxicity in water media. In this work, the effects of arsenic on the optical and photophysical properties of leaves of different aquatic plants (Vallisneria gigantea, Azolla filiculoides and Lemna minor) were evaluated. Reflectance spectra were recorded for the plant leaves from 300 to 2400 nm. The spectral distribution of the fluorescence was also studied and corrected for light re-absorption processes. Photosynthetic parameters (Fv/Fm and ΦPSII) were additionally calculated from the variable chlorophyll fluorescence recorded with a pulse amplitude modulated fluorometer. Fluorescence and reflectance properties for V. gigantea and A. filiculoides were sensitive to arsenic presence in contrast to the behaviour of L. minor. Observed changes in fluorescence spectra could be interpreted in terms of preferential damage in photosystem II. The quantum efficiency of photosystem II for the first two species was also affected, decreasing upon arsenic treatment. As a result of this research, V. gigantea and A. filiculoides were proposed as bioindicators of arsenic occurrence in aquatic media. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Peri-urban aquatic plant culture and skin disease in Phnom Penh, Cambodia.

    Science.gov (United States)

    Anh, Vuong Tuan; van der Hoek, Wim; Ersbøll, Annette Kjaer; Vicheth, Chan; Cam, Phung Dac; Dalsgaard, Anders

    2009-06-01

    A cross-sectional study with follow-up was done in five communities involved in aquaculture in peri-urban Phnom Penh, Cambodia, to assess the association between skin disease, particularly dermatitis and occupational wastewater exposure. From 200 selected households 650 household members aged > or = 15 years were visited and examined dermatologically three times in July 2004, January and May 2005. Overall dermatitis prevalence was 6.1%. However, all cases (116) were found in the two wastewater villages involved in aquatic plant culture. Risk factor analysis restricted to the two wastewater villages showed that involvement in wastewater-fed aquatic plant production increased the risk of dermatitis in the univariable analysis but not in the multivariable analysis. Among family members involved in wastewater-fed aquatic plant production a longer duration of daily wastewater contact did not increase the risk of dermatitis in the multivariable analysis. Wet season, older age and having a history of skin problems in the three months prior to each survey were associated significantly with dermatitis. Very few aquaculture workers applied personal protection and the factor had no significant effect on dermatitis. The present study did not show a consistent association between occupational exposure to wastewater and dermatitis, unlike similar Vietnamese studies.

  19. Dinitrogen fixation associated with shoots of aquatic carnivorous plants: is it ecologically important?

    Science.gov (United States)

    Sirová, Dagmara; Santrůček, Jiří; Adamec, Lubomír; Bárta, Jiří; Borovec, Jakub; Pech, Jiří; Owens, Sarah M; Santrůčková, Hana; Schäufele, Rudi; Storchová, Helena; Vrba, Jaroslav

    2014-07-01

    Rootless carnivorous plants of the genus Utricularia are important components of many standing waters worldwide, as well as suitable model organisms for studying plant-microbe interactions. In this study, an investigation was made of the importance of microbial dinitrogen (N2) fixation in the N acquisition of four aquatic Utricularia species and another aquatic carnivorous plant, Aldrovanda vesiculosa. 16S rRNA amplicon sequencing was used to assess the presence of micro-organisms with known ability to fix N2. Next-generation sequencing provided information on the expression of N2 fixation-associated genes. N2 fixation rates were measured following (15)N2-labelling and were used to calculate the plant assimilation rate of microbially fixed N2. Utricularia traps were confirmed as primary sites of N2 fixation, with up to 16 % of the plant-associated microbial community consisting of bacteria capable of fixing N2. Of these, rhizobia were the most abundant group. Nitrogen fixation rates increased with increasing shoot age, but never exceeded 1·3 μmol N g(-1) d. mass d(-1). Plant assimilation rates of fixed N2 were detectable and significant, but this fraction formed less than 1 % of daily plant N gain. Although trap fluid provides conditions favourable for microbial N2 fixation, levels of nif gene transcription comprised aquatic Utricularia, despite the large potential capacity, is the high concentration of NH4-N (2·0-4·3 mg L(-1)) in the trap fluid. Resulting from fast turnover of organic detritus, it probably inhibits N2 fixation in most of the microorganisms present. Nitrogen fixation is not expected to contribute significantly to N nutrition of aquatic carnivorous plants under their typical growth conditions; however, on an annual basis the plant-microbe system can supply nitrogen in the order of hundreds of mg m(-2) into the nutrient-limited littoral zone, where it may thus represent an important N source. © The Author 2014. Published by Oxford University

  20. The mitochondrial genome of an aquatic plant, Spirodela polyrhiza.

    Directory of Open Access Journals (Sweden)

    Wenqin Wang

    Full Text Available BACKGROUND: Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt genome could provide clues for the understanding of the evolution of mt genomes in plant. METHODS: Spirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitive assembly algorithm, the mt genome was successfully assembled. Gap closure and accuracy was determined with PCR products sequenced with the dideoxy method. CONCLUSIONS: This is the most compact monocot mitochondrial genome with 228,493 bp. A total of 57 genes encode 35 known proteins, 3 ribosomal RNAs, and 19 tRNAs that recognize 15 amino acids. There are about 600 RNA editing sites predicted and three lineage specific protein-coding-gene losses. The mitochondrial genes, pseudogenes, and other hypothetical genes (ORFs cover 71,783 bp (31.0% of the genome. Imported plastid DNA accounts for an additional 9,295 bp (4.1% of the mitochondrial DNA. Absence of transposable element sequences suggests that very few nuclear sequences have migrated into Spirodela mtDNA. Phylogenetic analysis of conserved protein-coding genes suggests that Spirodela shares the common ancestor with other monocots, but there is no obvious synteny between Spirodela and rice mtDNAs. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly four-fifths of the Spirodela mitochondrial genome is of unknown origin and function. Although it contains a similar chloroplast DNA content and range of RNA editing as other monocots, it is void of nuclear insertions, active gene loss, and comprises large regions of sequences of unknown origin in non-coding regions. Moreover, the lack of synteny with known mitochondrial genomic sequences shed new light on the early evolution of monocot

  1. The mitochondrial genome of an aquatic plant, Spirodela polyrhiza.

    Science.gov (United States)

    Wang, Wenqin; Wu, Yongrui; Messing, Joachim

    2012-01-01

    Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt) genome could provide clues for the understanding of the evolution of mt genomes in plant. Spirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitive assembly algorithm, the mt genome was successfully assembled. Gap closure and accuracy was determined with PCR products sequenced with the dideoxy method. This is the most compact monocot mitochondrial genome with 228,493 bp. A total of 57 genes encode 35 known proteins, 3 ribosomal RNAs, and 19 tRNAs that recognize 15 amino acids. There are about 600 RNA editing sites predicted and three lineage specific protein-coding-gene losses. The mitochondrial genes, pseudogenes, and other hypothetical genes (ORFs) cover 71,783 bp (31.0%) of the genome. Imported plastid DNA accounts for an additional 9,295 bp (4.1%) of the mitochondrial DNA. Absence of transposable element sequences suggests that very few nuclear sequences have migrated into Spirodela mtDNA. Phylogenetic analysis of conserved protein-coding genes suggests that Spirodela shares the common ancestor with other monocots, but there is no obvious synteny between Spirodela and rice mtDNAs. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly four-fifths of the Spirodela mitochondrial genome is of unknown origin and function. Although it contains a similar chloroplast DNA content and range of RNA editing as other monocots, it is void of nuclear insertions, active gene loss, and comprises large regions of sequences of unknown origin in non-coding regions. Moreover, the lack of synteny with known mitochondrial genomic sequences shed new light on the early evolution of monocot mitochondrial genomes.

  2. Determination of main components and anaerobic rumen digestibility of aquatic plants in vitro using near-infrared-reflectance spectroscopy.

    Science.gov (United States)

    Yue, Zheng-Bo; Zhang, Meng-Lin; Sheng, Guo-Ping; Liu, Rong-Hua; Long, Ying; Xiang, Bing-Ren; Wang, Jin; Yu, Han-Qing

    2010-04-01

    A near-infrared-reflectance (NIR) spectroscopy-based method is established to determine the main components of aquatic plants as well as their anaerobic rumen biodegradability. The developed method is more rapid and accurate compared to the conventional chemical analysis and biodegradability tests. Moisture, volatile solid, Klason lignin and ash in entire aquatic plants could be accurately predicted using this method with coefficient of determination (r(2)) values of 0.952, 0.916, 0.939 and 0.950, respectively. In addition, the anaerobic rumen biodegradability of aquatic plants, represented as biogas and methane yields, could also be predicted well. The algorithm of continuous wavelet transform for the NIR spectral data pretreatment is able to greatly enhance the robustness and predictive ability of the NIR spectral analysis. These results indicate that NIR spectroscopy could be used to predict the main components of aquatic plants and their anaerobic biodegradability. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  3. Toxicities of oils, dispersants and dispersed oils to algae and aquatic plants: review and database value to resource sustainability

    Science.gov (United States)

    Published toxicity results are reviewed for oils, dispersants and dispersed oils and aquatic plants. The historical phytotoxicity database consists largely of results from a patchwork of research conducted after oil spills to marine waters. Toxicity information is available for ...

  4. [Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia].

    Science.gov (United States)

    Schmidt-Mumm, Udo; Vargas Ríos, Orlando

    2012-03-01

    Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia. High Andean paramo ecosystems are an important water resource for many towns, and major cities in this region. The aquatic and wetland vegetation of different paramo lakes, pond, swamps and bogs was studied according to the classical phytosociological approach, which is based on homogenous stands, but excludes any border phenomena or transitional zone. The present research aimed at determining the aquatic and wetland vegetation along different moisture gradients. A total of 89 species in 30 transects were reported, of which Crassula venezuelensis, Carex honplandii, Callitriche nubigena, Eleocharis macrostachya, Ranunculus flagelliformis, R. nubigenus, Eleocharis stenocarpa, Galium ascendens y Alopecurus aequalis were present in more than one third of the transects. Numerical classification and indicator species analysis resulted in the definition of the next 18 communities: 1) Calamagrostis effusa, 2) Sphagnum cuspidatum, 3) Cyperus rufus, 4) Eleocharis stenocarpa, 5) Carex acutata, 6) Poa annua,7) Valeriana sp., 8) Ranunculus flagelliformis, 9) Carex bonplandii, 10) Festuca andicola. 11) Muhlenbergia fustigiata, 12) Elatine paramoana, 13) Isoëtes palmeri, 14) Crassula venezuelensis, 15) Lilaeopsis macloviana, 16) Callitriche nubigena, 17) Potamogeton paramoanus and 18) Potamogeton illinoensis. The ordination of communities reveals the presence of three different aquatic-terrestrial gradients which are related to the life form structure of species that characterized the various communities. We concluded that patchiness and heterogeneity of the vegetation is mainly the result of alterations caused by human activities (burning, cattle raise and material extraction for road and dam construction).

  5. Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

    Science.gov (United States)

    Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

    1975-01-01

    Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

  6. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor.

    Science.gov (United States)

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M

    2017-04-01

    Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ 13 C) were measured among treatments ranging from 0 to 15000nmol/L-sucralose and 0-323nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ 13 C of L. minor at environmentally relevant concentrations. The increase of δ 13 C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor-a mixotrophic plant-can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine significantly decreased L. minor root growth, daily growth rate, and asexual reproduction at 323nmol/L-fluoxetine; however, ambiguity remains regarding the mechanisms responsible and the applicability of these extreme concentrations unprecedented in the natural environment. To our knowledge, this was the

  7. Growth-form and spatiality driving the functional difference of native and alien aquatic plants in Europe.

    Science.gov (United States)

    Lukács, Balázs A; Vojtkó, Anna E; Mesterházy, Attila; Molnár V, Attila; Süveges, Kristóf; Végvári, Zsolt; Brusa, Guido; Cerabolini, Bruno E L

    2017-02-01

    Trait-based approaches are widely used in community ecology and invasion biology to unravel underlying mechanisms of vegetation dynamics. Although fundamental trade-offs between specific traits and invasibility are well described among terrestrial plants, little is known about their role and function in aquatic plant species. In this study, we examine the functional differences of aquatic alien and native plants stating that alien and native species differ in selected leaf traits. Our investigation is based on 60 taxa (21 alien and 39 native) collected from 22 freshwater units of Hungarian and Italian lowlands and highlands. Linear mixed models were used to investigate the effects of nativeness on four fundamental traits (leaf area, leaf dry matter content, specific leaf area, and leaf nitrogen content), while the influence of growth-form, altitude, and site were employed simultaneously. We found significantly higher values of leaf areas and significantly lower values of specific leaf areas for alien species if growth-form was included in the model as an additional predictor.We showed that the trait-based approach of autochthony can apply to aquatic environments similar to terrestrial ones, and leaf traits have relevance in explaining aquatic plant ecology whether traits are combined with growth-forms as a fixed factor. Our results confirm the importance of traits related to competitive ability in the process of aquatic plant invasions. Alien aquatic plants can be characterized as species producing soft leaves faster. We argue that the functional traits of alien aquatic plants are strongly growth-form dependent. Using the trait-based approach, we found reliable characteristics of aquatic plants related to species invasions, which might be used, for example, in conservation management.

  8. Replacement of cowdung by fermentation of aquatic and terrestrial plants for use as fuel, fertilizer and biogas plant feed

    Energy Technology Data Exchange (ETDEWEB)

    Das, C.R.; Ghatnekar, S.D.

    1979-01-01

    With 85% of the entire Indian population living in villages and 98% of the household energy requirement of the rural population demanded for cooking, research was undertaken on the supply of biomass for those Indians who do not have cattle. This research was carried out on the fermentation of aquatic and terrestrial plants for use in biogas generation. The plants utilized for biogas generation are: water hyacinth, water lettuce, African payal, duck weed, water spinach, cattail ramban, ipil-ipil, morning glory, paragrass, purple nutsedge, and durva grass.

  9. Understanding Aquaporin Transport System in Eelgrass (Zostera marina L., an Aquatic Plant Species

    Directory of Open Access Journals (Sweden)

    S. M. Shivaraj

    2017-08-01

    Full Text Available Aquaporins (AQPs are a class of integral membrane proteins involved in the transport of water and many other small solutes. The AQPs have been extensively studied in many land species obtaining water and nutrients from the soil, but their distribution and evolution have never been investigated in aquatic plant species, where solute assimilation is mostly through the leaves. In this regard, identification of AQPs in the genome of Zostera marina L. (eelgrass, an aquatic ecological model species could reveal important differences underlying solute uptake between land and aquatic species. In the present study, genome-wide analysis led to the identification of 25 AQPs belonging to four subfamilies, plasma membrane intrinsic proteins (PIPs, tonoplast intrinsic proteins (TIPs, nodulin 26-like intrinsic proteins (NIPs, small basic intrinsic proteins (SIPs in eelgrass. As in other monocots, the XIP subfamily was found to be absent from the eelgrass genome. Further classification of subfamilies revealed a unique distribution pattern, namely the loss of the NIP2 (NIP-III subgroup, which is known for silicon (Si transport activity and ubiquitously present in monocot species. This finding has great importance, since the eelgrass population stability in natural niche is reported to be associated with Si concentrations in water. In addition, analysis of available RNA-seq data showed evidence of expression in 24 out of the 25 AQPs across four different tissues such as root, vegetative tissue, male flower and female flower. In contrast to land plants, higher expression of PIPs was observed in shoot compared to root tissues. This is likely explained by the unique plant architecture of eelgrass where most of the nutrients and water are absorbed by shoot rather than root tissues. Similarly, higher expression of the TIP1 and TIP5 families was observed specifically in male flowers suggesting a role in pollen maturation. This genome-wide analysis of AQP distribution

  10. Natural attenuation of weathered oil using aquatic plants in a farm in Southeast Mexico.

    Science.gov (United States)

    Rivera-Cruz, María Del Carmen; Trujillo-Narcía, Antonio; Trujillo-Rivera, Eduardo A; Arias-Trinidad, Alfredo; Mendoza-López, María Remedios

    2016-09-01

    An experiment was conducted in field for three years to assess the sustainability of aquatic plants Leersia hexandra, Cyperus articulatus, and Eleocharis palustris for use in the removal of total hydrocarbons of weathered oil in four areas contaminated with 60916-119373 mg/kg of hydrocarbons. The variables evaluated were coverage of plant, dry matter, density of plant growth-promoting rhizobacteria, and the removal of total weathered oil. The variables showed statistical differences (p = 0.05) due to the effects of time and the amount of oil in the soil. The three aquatic plants survived on the farm during the 36-month evaluation. The grass L. hexandra yielded the greatest coverage of plant but was inhibited by the toxicity of the oil, which, in contrast, stimulated the coverage of C. articulatus. The rhizosphere of L. hexandra in control soil was more densely colonized by N-fixing bacteria, while the density of phosphate and potassium solubilizing rhizobacteria was stimulated by exposure to oil. C. articulatus coverage showed positive relationship with the removal of weathered oil; positive effect between rhizosphere and L. hexandra grass coverage was also identified. These results contributed to the removal of weathered oil in Gleysols flooded and affected by chronic discharges of crude oil.

  11. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  12. Ubiquitous water-soluble molecules in aquatic plant exudates determine specific insect attraction.

    Directory of Open Access Journals (Sweden)

    Julien Sérandour

    Full Text Available Plants produce semio-chemicals that directly influence insect attraction and/or repulsion. Generally, this attraction is closely associated with herbivory and has been studied mainly under atmospheric conditions. On the other hand, the relationship between aquatic plants and insects has been little studied. To determine whether the roots of aquatic macrophytes release attractive chemical mixtures into the water, we studied the behaviour of mosquito larvae using olfactory experiments with root exudates. After testing the attraction on Culex and Aedes mosquito larvae, we chose to work with Coquillettidia species, which have a complex behaviour in nature and need to be attached to plant roots in order to obtain oxygen. This relationship is non-destructive and can be described as commensal behaviour. Commonly found compounds seemed to be involved in insect attraction since root exudates from different plants were all attractive. Moreover, chemical analysis allowed us to identify a certain number of commonly found, highly water-soluble, low-molecular-weight compounds, several of which (glycerol, uracil, thymine, uridine, thymidine were able to induce attraction when tested individually but at concentrations substantially higher than those found in nature. However, our principal findings demonstrated that these compounds appeared to act synergistically, since a mixture of these five compounds attracted larvae at natural concentrations (0.7 nM glycerol, <0.5 nM uracil, 0.6 nM thymine, 2.8 nM uridine, 86 nM thymidine, much lower than those found for each compound tested individually. These results provide strong evidence that a mixture of polyols (glycerol, pyrimidines (uracil, thymine, and nucleosides (uridine, thymidine functions as an efficient attractive signal in nature for Coquillettidia larvae. We therefore show for the first time, that such commonly found compounds may play an important role in plant-insect relationships in aquatic eco-systems.

  13. Accumulation of uranium by aquatic plants in field conditions: Prospects for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Favas, Paulo J.C., E-mail: pjcf@utad.pt [School of Life Sciences and the Environment, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Pratas, João [Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Varun, Mayank; D' Souza, Rohan; Paul, Manoj S. [Department of Botany, St. John' s College, Agra 282 002 (India)

    2014-02-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n = 200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1217 μg L{sup −1}. The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4979 mg kg{sup −1}) followed by Callitriche stagnalis (1963 mg kg{sup −1}), Callitriche hamulata (379 mg kg{sup −1}), Ranunculus peltatus subsp. saniculifolius (243 mg kg{sup −1}), Callitriche lusitanica (218 mg kg{sup −1}), and Ranunculus trichophyllus (65.8 mg kg{sup −1}). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg{sup −1}). Among the free-floating species, the highest U content (42.5 mg kg{sup −1}) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. - Highlights: • Exploration of U contamination extent in uraniferous province of Central Portugal • A group of previously untested species with the ability to accumulate U was assessed • U accumulation patterns in the species indicate their potential in bioindication and phytoremediation of U-contaminated water.

  14. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M., E-mail: danellelarson77@gmail.com

    2017-04-15

    Highlights: • Sucralose increased leaf area and photosynthetic capacity of Lemna minor. • Sucralose increased δ {sup 13}C of Lemna, indicating substantial uptake and assimilation. • 100 μg/L-fluoxetine decreased Lemna minor growth and asexual reproduction. - Abstract: Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ{sup 13}C) were measured among treatments ranging from 0 to 15000 nmol/L-sucralose and 0–323 nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ {sup 13}C of L. minor at environmentally relevant concentrations. The increase of δ {sup 13}C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor—a mixotrophic plant—can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine

  15. Photoacoustic analysis of the ultrasonic irradiation effect in the photosynthetic activity in aquatic lirium plants.

    Science.gov (United States)

    Calderón, A; Cardona, A; Nogal, U; Juárez Gracia, A G; Marín, E; Muñoz Hernández, R A

    2014-01-01

    We report, the application of the photoacoustic technique for monitoring the photosynthesis evolution in aquatic lirium (Eichhornia Crassipes), before and after it was exposed to ultrasonic irradiations. We obtained the disappearance of the phototobaric contribution in the PA signal measured for the irradiated samples with ultrasound of 17 kHz, and therefore of a possible damage in the centers producing the photosynthesis, due to the irradiation. These results show the utility of the ultrasonic irradiation, as well as, of the photosynthesis monitoring by means of the photoacoustic technique, for the elaboration and establishment of methodologies in the control of this aquatic plant, whose propagation causes many consequences extremely unfavorable for the environment, as well as for the diverse human activities that are developed in the bodies of water in the tropical and sub-tropical regions of the world. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. [Ammonia-oxidizing bacteria community composition at the root zones of aquatic plants after ecological restoration].

    Science.gov (United States)

    Xing, Peng; Kong, Fan-xiang; Chen, Kai-ning; Chen, Mei-jun; Wu, Xiao-dong

    2008-08-01

    To investigate the effects of aquatic plants on ammonia-oxidizing bacteria (AOB) at their root zones, four species of aquatic plants were selected, Phragmites communis, Typha angustifolia L., Potamogeton crispus L., and Limnanthemun nymphoides, which were widely used in ecological restorations. AOB in the samples were enumerated by most-probable-number (MPN) method. Nested polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) procedures were performed with ammonia oxidizer-selective primers. Main DGGE bands were excised from the gel and sequenced for phylogenetic affiliation. Results indicate that AOB densities are always higher at the root zones of emergent plants (Phragmites communis 2.8 x 10(5) cells/g and Typha angustifolia L.4.3 x 10(5) cells/g) than those of submerged and floating-leaved plant (Potamogeton crispus L. 9.3 x 10(4) cells/g and Limnanthemun nymphoides 7.7 x 10(4) cells/g). At the root zones, the oxidation-reduction potential is above zero and NH4+ concentration is lower than it in the bare surface sediment. Fourteen major bands were recovered from the DGGE gel, re-amplified and sequenced. Although the identified bands have their respective similar sequences in GenBank, most of them are related to Nitrosomonas-like. This type of bacteria would play an important role of nitrogen cycle in lake sediment after ecological restoration.

  17. Uptake of cesium and cobalt radionuclides from simulated radioactive wastewater by Ludwigia stolonifera aquatic plant

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Bayoumi, T.A. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Mahmoud, H.H. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Central Laboratory for Elemental and Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority (Egypt); Aglan, R.F. [Department of Analytical Chemistry, Hot Laboratories Center, Atomic Energy Authority, 13759 (Egypt)

    2017-04-15

    Highlights: • Radioactive contamination is a serious environmental problem. • Phytoremediation is a proper technique for soil and water decontamination. • Aquatic plant, Ludwigia stolonifera, for bioaccumulation of radionuclides. • Factors affecting uptake efficiency of {sup 137}Cs and {sup 60}Co radionuclides. - Abstract: The article reported herein was conducted as part of comprehensive study considered to evaluate the efficiency of Ludwigia stolonifera as a local aquatic plant located in the Egyptian environment for phytoremediation of hazardous toxic and radioactive elements dissolved in aqueous wastes dispersed from industrial and urban applications through the human activities. Ludwigia stolonifera was immersed in single and binary solution of {sup 60}Co and {sup 137}Cs. The specific uptake rate of plant was determined at various activity contents of radionuclides, multiplied masses of plant, lighting exposure and different pH values. Accumulation of {sup 60}Co and {sup 137}Cs in mixture was more than 95% and 65% respectively. pH was less effective than the other evaluated parameters.

  18. A comparative study of the modeled effects of atrazine on aquatic plant communities in midwestern streams.

    Science.gov (United States)

    Nair, Shyam K; Bartell, Steven M; Brain, Richard A

    2015-11-01

    Potential effects of atrazine on the nontarget aquatic plants characteristic of lower-order streams in the Midwestern United States were previously assessed using the Comprehensive Aquatic System Model (CASMATZ ). Another similar bioenergetics-based, mechanistic model, AQUATOX, was examined in the present study, with 3 objectives: 1) to develop an AQUATOX model simulation similar to the CASMATZ model reference simulation in describing temporal patterns of biomass production by modeled plant populations, 2) to examine the implications of the different approaches used by the models in deriving plant community-based levels of concern (LOCs) for atrazine, and 3) to determine the feasibility of implementing alternative ecological models to assess ecological impacts of atrazine on lower-order Midwestern streams. The results of the present comparative modeling study demonstrated that a similar reference simulation to that from the CASMATZ model could be developed using the AQUATOX model. It was also determined that development of LOCs and identification of streams with exposures in excess of the LOCs were feasible with the AQUATOX model. Compared with the CASMATZ model results, however, the AQUATOX model consistently produced higher estimates of LOCs and generated non-monotonic variations of atrazine effects with increasing exposures. The results of the present study suggest an opportunity for harmonizing the treatments of toxicity and toxicity parameter estimation in the CASMATZ and the AQUATOX models. Both models appear useful in characterizing the potential impacts of atrazine on nontarget aquatic plant populations in lower-order Midwestern streams. The present model comparison also suggests that, with appropriate parameterization, these process-based models can be used to assess the potential effects of other xenobiotics on stream ecosystems. © 2015 SETAC.

  19. Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams.

    Science.gov (United States)

    Baattrup-Pedersen, Annette; Göthe, Emma; Riis, Tenna; O'Hare, Matthew T

    2016-02-01

    Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental

  20. Desiccation of sediments affects assimilate transport within aquatic plants and carbon transfer to microorganisms.

    Science.gov (United States)

    von Rein, I; Kayler, Z E; Premke, K; Gessler, A

    2016-11-01

    With the projected increase in drought duration and intensity in future, small water bodies, and especially the terrestrial-aquatic interfaces, will be subjected to longer dry periods with desiccation of the sediment. Drought effects on the plant-sediment microorganism carbon continuum may disrupt the tight linkage between plants and microbes which governs sediment carbon and nutrient cycling, thus having a potential negative impact on carbon sequestration of small freshwater ecosystems. However, research on drought effects on the plant-sediment carbon transfer in aquatic ecosystems is scarce. We therefore exposed two emergent aquatic macrophytes, Phragmites australis and Typha latifolia, to a month-long summer drought in a mesocosm experiment. We followed the fate of carbon from leaves to sediment microbial communities with 13 CO 2 pulse labelling and microbial phospholipid-derived fatty acid (PLFA) analysis. We found that drought reduced the total amount of carbon allocated to stem tissues but did not delay the transport. We also observed an increase in accumulation of 13 C-labelled sugars in roots and found a reduced incorporation of 13 C into the PLFAs of sediment microorganisms. Drought induced a switch in plant carbon allocation priorities, where stems received less new assimilates leading to reduced starch reserves whilst roots were prioritised with new assimilates, suggesting their use for osmoregulation. There were indications that the reduced carbon transfer from roots to microorganisms was due to the reduction of microbial activity via direct drought effects rather than to a decrease in root exudation or exudate availability. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Effects of acidification on metal accumulation by aquatic plants and invertebrates. 2. Wetlands, ponds and small lakes

    Science.gov (United States)

    Albers, P.H.; Camardese, M.B.

    1993-01-01

    High concentrations of trace metals in the water of low-pH lakes and streams could result in elevated amounts of metals within or adsorbed to aquatic plants and, possibly, invertebrates. Concentrations of Al, Cd, Ca, Cu, Fe, Pb, Mg, Mn, Hg, Ni, P, and Zn were compared in water, plants, and aquatic invertebrates of wetlands, ponds, and small lakes in Maryland and Maine. The accumulation of metals by aquatic plants and insects and the concentrations of metals in water were not greatly affected by pH. None of the metal concentrations significantly correlated with metals in insects. Plant metal concentrations poorly correlated with metal concentrations in water. Concentrations of metals exceeded acceptable dietary levels more frequently in plants than in invertebrates. Concerns about metal toxicity in birds that feed on invertebrates and plants from acidified waters seem to be unwarranted. Positive correlations among pH, Ca in water, Ca in insects, and Ca in plants imply that acidification can reduce the Ca content of aquatic biota. Aquatic insects were low in Ca, but crayfishes and snails, which are adversely affected by low pH, were very high. A concern for waterfowl is Ca deprivation from decreased Ca availability in low-pH wetlands, ponds, and small lakes.

  2. Plant-microbe interaction in aquatic system and their role in the management of water quality: a review

    Science.gov (United States)

    Srivastava, Jatin K.; Chandra, Harish; Kalra, Swinder J. S.; Mishra, Pratibha; Khan, Hena; Yadav, Poonam

    2017-06-01

    Microbial assemblage as biofilm around the aquatic plant forms a firm association that largely depends upon the mutual supplies of nutrients, e.g., microbes interact with plants in an aquatic system most likely for organic carbon and oxygen, whereas plants receive defensive immunity and mineral exchange. Apart from the mutual benefits, plant-microbe interactions also influence the water quality especially at rhizosphere providing inherent ability to the aquatic system for the mitigation of pollution from the water column. The review presents and in-depth information along with certain research advancements made in the field of ecological and bio/chemical aspects of plant-microbe interactions and the underlying potential to improve water quality.

  3. A quantitative and qualitative comparison of aquatic and terrestrial plant lignin phenols: Critical information for paleoecological reconstructions

    Science.gov (United States)

    Thomas, E. K.; Gao, L.; Huang, Y.

    2009-12-01

    Currently, lignin phenols are used in marine and lacustrine ecosystems as proxies for terrestrial vegetation inputs. Lignins are found in all vascular plants, where they play a crucial role in conduction of water, nutrients and photosynthates through the vascular system, and where they provide structural support. Furthermore, different types of lignin phenols are found in specific types of vegetation (e.g., both syringyl and vanillyl phenols are in angiosperm wood, but only vanillyl phenols are in gymnosperm wood). The ratio of lignin phenols (e.g. syringyl:vanillyl) is indicative of the type of plant from which the lignin phenols were derived. Studies that examine lignin phenols in sedimentary archives assume that lignin phenols are derived solely from terrestrial plants, and changes in the types of lignin phenols are therefore assumed to mark changes in terrestrial vegetation. These assumptions may be flawed, however, because many aquatic plants, including those that are submerged, are vascular, yet little is known about the type and concentration of lignin phenols present in aquatic vascular plants. This knowledge is imperative to the success of paleoecological studies that utilize lignin phenols as a geochemical proxy for terrestrial vegetation. Furthermore, lignin phenols may be important targets for compound-specific radiocarbon dating, which is useful when suitable macrofossils are unavailable. Knowing the origin of the molecules used for radiocarbon dating, however, (i.e. whether they are terrestrial or aquatic) is critical to obtaining meaningful chronologies. We isolated and analyzed lignin phenol monomers from different types of aquatic vascular plants. All plants analyzed are angiosperms, but they occupy different niches in aquatic plant communities: floating, emergent and submergent. We also analyzed different parts of aquatic plants (i.e., stems and leaves). We found lignin phenols in all aquatic species that we analyzed, which highlights the need for

  4. Fast method for the simultaneous determination of monomethylmercury and inorganic mercury in rice and aquatic plants.

    Science.gov (United States)

    Jiménez-Moreno, María; Lominchar, Miguel Ángel; Sierra, María José; Millán, Rocío; Martín-Doimeadios, Rosa Carmen Rodríguez

    2018-01-01

    Recent investigations revealed that monomethylmercury (MMHg) can be absorbed and accumulated by plants, i.e. rice crops, thus becoming an important route of human exposure to MMHg through diet. The increasing concern about this fact makes that appropriate analytical methods for Hg speciation in these samples are urgently required. Therefore, the aim of this work has been the development of a fast and sensitive method which enables the simultaneous determination of MMHg and inorganic Hg in rice and aquatic plants. The proposed methodology is based on the extraction of Hg species by closed-vessel microwave heating, subsequent derivatization by ethylation and analysis by gas chromatography coupled to atomic fluorescence detection via pyrolysis (GC-pyro-AFS). A careful optimization of the extraction, using both acid (6N HNO 3 ) and alkaline (tetramethylammonium hydroxide, TMAH) extractants, and derivatization conditions has been carried out. Spiked and unspiked aquatic plants (Typha domingensis) and CRMs certified for Total-Hg (BCR-60, BCR-482 and NCS ZC73027, corresponding to aquatic plant, lichen and rice, respectively) have been used. Under the final optimized conditions the simultaneous determination of MMHg and inorganic Hg can be carried out in less than 40min with no tedious clean-up steps. Quantitative recoveries (from 92% to 101%) were obtained in aquatic plants (Typha domingensis) and CRMs spiked with known concentrations of MMHg. For unspiked BCR-60 and BCR-482, no statistically significant differences (p=0.05) were found in Total-Hg concentrations between those obtained by the sum of species and the certified values for both acid and alkaline extraction. For the analysis of low Hg polluted samples, an additional preconcentration step by evaporation under nitrogen stream was required but adequate blanks were only obtained for acid extraction. Detection limits in the low ng/g range (0.7-1.0ng/g) were consequently achieved for both Hg species in the case of

  5. Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams

    Energy Technology Data Exchange (ETDEWEB)

    Baattrup-Pedersen, Annette, E-mail: abp@bios.au.dk [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Göthe, Emma [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Riis, Tenna [Department of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1135, Room 217, DK-8000 Aarhus C (Denmark); O' Hare, Matthew T. [Centre for Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom)

    2016-02-01

    Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental

  6. Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy.

    Science.gov (United States)

    Fukuda, Shin-Ya; Iwamoto, Koji; Atsumi, Mika; Yokoyama, Akiko; Nakayama, Takeshi; Ishida, Ken-Ichiro; Inouye, Isao; Shiraiwa, Yoshihiro

    2014-01-01

    The Fukushima 1 Nuclear Power Plant accident in March 2011 released an enormously high level of radionuclides into the environment, a total estimation of 6.3 × 10¹⁷ Bq represented by mainly radioactive Cs, Sr, and I. Because these radionuclides are biophilic, an urgent risk has arisen due to biological intake and subsequent food web contamination in the ecosystem. Thus, urgent elimination of radionuclides from the environment is necessary to prevent substantial radiopollution of organisms. In this study, we selected microalgae and aquatic plants that can efficiently eliminate these radionuclides from the environment. The ability of aquatic plants and algae was assessed by determining the elimination rate of radioactive Cs, Sr and I from culture medium and the accumulation capacity of radionuclides into single cells or whole bodies. Among 188 strains examined from microalgae, aquatic plants and unidentified algal species, we identified six, three and eight strains that can accumulate high levels of radioactive Cs, Sr and I from the medium, respectively. Notably, a novel eustigmatophycean unicellular algal strain, nak 9, showed the highest ability to eliminate radioactive Cs from the medium by cellular accumulation. Our results provide an important strategy for decreasing radiopollution in Fukushima area.

  7. Fate of psychoactive compounds in wastewater treatment plant and the possibility of their degradation using aquatic plants.

    Science.gov (United States)

    Mackuľak, Tomáš; Mosný, Michal; Škubák, Jaroslav; Grabic, Roman; Birošová, Lucia

    2015-03-01

    In this study we analyzed and characterized 29 psychoactive remedies, illicit drugs and their metabolites in single stages of wastewater treatment plants in the capital city of Slovakia. Psychoactive compounds were present within all stages, and tramadol was detected at a very high concentration (706 ng/L). Significant decreases of codeine, THC-COOH, cocaine and buprenorphine concentration were observed in the biological stage. Consequently, we were interested in the possibility of alternative tertiary post-treatment of effluent water with the following aquatic plants: Cabomba caroliniana, Limnophila sessiliflora, Egeria najas and Iris pseudacorus. The most effective plant for tertiary cleansing was I. pseudacorus which demonstrated the best pharmaceutical removal capacity. After 48 h codeine and citalopram was removed with 87% efficiency. After 96 h were all analyzed compounds were eliminated with efficiencies above 58%. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Ecological effect and risk towards aquatic plants induced by perfluoroalkyl substances: Bridging natural to culturing flora.

    Science.gov (United States)

    Zhou, Yunqiao; Wang, Tieyu; Jiang, Zhaoze; Kong, Xiaoxiao; Li, Qifeng; Sun, Yajun; Wang, Pei; Liu, Zhaoyang

    2017-01-01

    In the present study, the concentrations and proportions of perfluoroalkyl substances (PFASs) in water and sediments (in different seasons) from the Qing River were investigated. The highest concentration of PFASs in water (207.59 ng L -1 ) was found in summer. The composition of PFASs in water changed with time, perfluorobutane sulfonate (PFBS) was the predominant compound in spring and summer, while long-chain PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), started to increase in autumn and winter. The PFASs concentration in sediments ranged from 0.96 to 4.05 ng g -1 dw. The proportion of long-chain PFASs was higher than that of short-chain PFASs in sediments, the dominant component in sediments was PFOA with a contribution of 24.6-75.4% to total PFASs in sediments, followed by PFOS. The concentrations of PFASs in roots of emergent plants were relatively higher than those in submerged plants. However, the translocation effect of PFASs was not remarkable. Bioaccumulation factors (BAFs) of the aquatic plants indicated the absorption of PFASs were effective. BAFs in submerged plants basically increased with increasing chain length accordingly. In general, aquatic plants had the absorption preference for long-chain PFASs, especially PFOS, which was the predominant compounds in both submerged and emergent plants. Based on the results above, hornworts were selected to be cultivated indoor in the nutrient solution spiked gradient concentrations of PFOS to assess the general ecological risk. The results revealed that hornworts were resistant to PFOS and might be used as remediation flora to eliminate PFOS contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Toxic Effects of Nickel Oxide Bulk and Nanoparticles on the Aquatic Plant Lemna gibba L.

    Directory of Open Access Journals (Sweden)

    Abdallah Oukarroum

    2015-01-01

    Full Text Available The aquatic plant Lemna gibba L. was used to investigate and compare the toxicity induced by 30 nm nickel oxide nanoparticles (NiO-NPs and nickel(II oxide as bulk (NiO-Bulk. Plants were exposed during 24 h to 0–1000 mg/L of NiO-NPs or NiO-Bulk. Analysis of physicochemical characteristics of nanoparticles in solution indicated agglomerations of NiO-NPs in culture medium and a wide size distribution was observed. Both NiO-NPs and NiO-Bulk caused a strong increase in reactive oxygen species (ROS formation, especially at high concentration (1000 mg/L. These results showed a strong evidence of a cellular oxidative stress induction caused by the exposure to NiO. Under this condition, NiO-NPs and NiO-Bulk induced a strong inhibitory effect on the PSII quantum yield, indicating an alteration of the photosynthetic electron transport performance. Under the experimental conditions used, it is clear that the observed toxicity impact was mainly due to NiO particles effect. Therefore, results of this study permitted determining the use of ROS production as an early biomarker of NiO exposure on the aquatic plant model L. gibba used in toxicity testing.

  10. Particle bombardment and subcellular protein localization analysis in the aquatic plant Egeria densa

    Directory of Open Access Journals (Sweden)

    Yasuhide Osaki

    2017-09-01

    Full Text Available Particle bombardment is a powerful and relatively easy method for transient expression of genes of interest in plant cells, especially those that are recalcitrant to other transformation methods. This method has facilitated numerous analyses of subcellular localization of fluorescent fusion protein constructs. Particle bombardment delivers genes to the first layer of plant tissue. In leaves of higher plants, epidermal cells are the first cell layer. Many studies have used the epidermal cell layer of onion bulb (Allium cepa as the experimental tissue, because these cells are relatively large. However, onion epidermal cells lack developed plastids (i.e., chloroplasts, thereby precluding subcellular localization analysis of chloroplastic proteins. In this study, we developed a protocol for particle bombardment of the aquatic plant Egeria densa, and showed that it is a useful system for subcellular localization analysis of higher plant proteins. E. densa leaflets contain only two cell layers, and cells in the adaxial layer are sufficiently large for observation. The cells in both layers contain well-developed chloroplasts. We fused fluorescent proteins to conventional plant localization signals for the nucleus, cytosol, mitochondria, peroxisome, and chloroplast, and used particle bombardment to transiently express these fusion constructs in E. densa leaves. The plant subcellular localization signals functioned normally and displayed the expected distributions in transiently transformed E. densa cells, and even chloroplastic structures could be clearly visualized.

  11. Activated carbon derived from harmful aquatic plant for high stable supercapacitors

    Science.gov (United States)

    Li, Jiangfeng; Wu, Qingsheng

    2018-01-01

    Considering cost and environmental protection, the harmful aquatic plant altemanthera philoxeroides derived carbon material with super high specific surface area (2895 m2 g-1) is an ideal electrode material for supercapacitor. The structure and composition of these carbon materials were characterized by SEM, EDS, XPS and BET measurements. The obtained material exhibits a maximum specific capacitance of 275 F g-1 at 0.5 A g-1 and retains a capacitance of 210 F g-1 even at 50 A g-1. In addition, it also shows excellent capacity retention of 5000 cycles at 10 A g-1.

  12. Development of microsatellite markers for Euryale ferox (Nymphaeaceae), an endangered aquatic plant species in Japan.

    Science.gov (United States)

    Imanishi, Ayumi; Kaneko, Shingo; Isagi, Yuji; Imanishi, Junichi; Natuhara, Yosihiro; Morimoto, Yukihiro

    2011-08-01

    Microsatellite markers were developed to investigate genetic diversity and genetic structure of Euryale ferox, a vulnerable aquatic plant. Ten microsatellite loci were isolated and characterized for this species. Eight loci showed polymorphisms with two or three alleles per locus. As for the polymorphic markers, the expected and observed heterozygosities ranged from 0.00 to 0.08 and 0.17 to 0.64, respectively. The 10 microsatellite markers described here will be useful for investigating genetic diversity, genetic structure, and gene flow between populations of E. ferox.

  13. The Use of Aquatic Plants in Wastewater Treatment: A Literature Review.

    Science.gov (United States)

    1992-12-01

    Others are flat and slender, oval, or circular. Spirodela polyrhiza L. is the largest species of the family with flat circular fronds as large as...name for the family of small aquatic plants, Lemnaceae. Duckweeds consist of.about forty species in four well defined genera: Spirodela , Lemna, 9`607a...1.5 cm across. Lemna and Spirodela have short nonfunctional roots that are usually less than 10 mm in length but can be as long as 3 cm. Lemna species

  14. Introduction of human pharmaceuticals from wastewater treatment plants into the aquatic environment: a rural perspective.

    Science.gov (United States)

    Nebot, Carolina; Falcon, Raquel; Boyd, Kenneth G; Gibb, Stuart W

    2015-07-01

    Incomplete removal of pharmaceuticals during wastewater treatment can result in their discharge into the aquatic environment. The discharge of pharmaceuticals in wastewater treatment plant (WWTP) effluents into rivers, lakes and the oceans has led to detectable concentrations of pharmaceuticals in the aquatic environment in many countries. However, to date studies of WWTP discharges into the aquatic environment have largely been confined to areas of relatively high population density, industrial activity or systems impacted on by such areas. In this work, two sites in the far north of Scotland were used to assess whether, and which, pharmaceuticals were being introduced into natural waters in a rural environment with low population density. Samples from two WWTPs (with differing modes of operation), and one receiving water, the River Thurso, were analysed for the presence of 12 pharmaceuticals (diclofenac, clofibric acid, erythromycin, ibuprofen, mefenamic acid, paracetamol, propranolol, sulfamethoxazole, tamoxifen, trimethoprim and dextropropoxyphene). Ten of the 12 pharmaceuticals investigated were detected in at least one of the 40 WWTP effluent samples. Maximum concentrations ranged from 7 ng L(-1) (sulfamethoxazole) to 22.8 μg L(-1) (paracetamol) with diclofenac and mefenamic acid being present in all of samples analysed at concentrations between 24.2 and 927 ng L(-1) and 11.5 and 22.8 μg L(-1), respectively. Additionally, the presence of four pharmaceuticals at ng L(-1) levels in the River Thurso, into which one of the WWTPs discharges, shows that such discharges result in measurable levels of pharmaceuticals in the environment. This provides direct evidence that, even in rural areas with low population densities, effluents from WWTPs can produce quantifiable levels of human pharmaceutical in the natural aquatic environment. These observations indicate that human pharmaceuticals may be considered as contaminants, with potential to influence water quality

  15. Accumulation of arsenic by aquatic plants in large-scale field conditions: opportunities for phytoremediation and bioindication.

    Science.gov (United States)

    Favas, Paulo J C; Pratas, João; Prasad, M N V

    2012-09-01

    This work focuses on the potential of aquatic plants for bioindication and/or phytofiltration of arsenic from contaminated water. More than 71 species of aquatic plants were collected at 200 sampling points in running waters. The results for the 18 most representative plant species are presented here. The species Ranunculus trichophyllus, Ranunculus peltatus subsp. saniculifolius, Lemna minor, Azolla caroliniana and the leaves of Juncus effusus showed a very highly significant (Pplant species into natural water bodies. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Molecular adaptation of rbcL in the heterophyllous aquatic plant Potamogeton.

    Science.gov (United States)

    Iida, Satoko; Miyagi, Atsuko; Aoki, Seishiro; Ito, Motomi; Kadono, Yasuro; Kosuge, Keiko

    2009-01-01

    Heterophyllous aquatic plants show marked phenotypic plasticity. They adapt to environmental changes by producing different leaf types: submerged, floating and terrestrial leaves. By contrast, homophyllous plants produce only submerged leaves and grow entirely underwater. Heterophylly and submerged homophylly evolved under selective pressure modifying the species-specific optima for photosynthesis, but little is known about the evolutionary outcome of habit. Recent evolutionary analyses suggested that rbcL, a chloroplast gene that encodes a catalytic subunit of RuBisCO, evolves under positive selection in most land plant lineages. To examine the adaptive evolutionary process linked to heterophylly or homophylly, we analyzed positive selection in the rbcL sequences of ecologically diverse aquatic plants, Japanese Potamogeton. Phylogenetic and maximum likelihood analyses of codon substitution models indicated that Potamogeton rbcL has evolved under positive Darwinian selection. The positive selection has operated specifically in heterophyllous lineages but not in homophyllous ones in the branch-site models. This suggests that the selective pressure on this chloroplast gene was higher for heterophyllous lineages than for homophyllous lineages. The replacement of 12 amino acids occurred at structurally important sites in the quaternary structure of RbcL, two of which (residue 225 and 281) were identified as potentially under positive selection. Our analysis did not show an exact relationship between the amino acid replacements and heterophylly or homophylly but revealed that lineage-specific positive selection acted on the Potamogeton rbcL. The contrasting ecological conditions between heterophyllous and homophyllous plants have imposed different selective pressures on the photosynthetic system. The increased amino acid replacement in RbcL may reflect the continuous fine-tuning of RuBisCO under varying ecological conditions.

  17. Concentration of heavy metals in brook trout in comparison to aquatic plants and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Rady, M.D.

    1983-01-01

    From 1974 to 1977 the heavy metal content of river water, fishes (Salmo trutta fario), three aquatic plants (Cladophora glomerata, Potamogeton pectinatus, Zannichellia palustris), one river-bank plant (Phalaris arundinacea), and sediments (clay fraction) taken from the River Leine, up and downstream of Goettingen, were determined. Galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. The average level of heavy metals in the river water corresponded to that of the Ems, Elbe and Weser, but was lower than that of the Neckar, Rhine and Danube. It was also below the European Community Guidelines (1975) on the quality of water used for the artificial recharging of ground water. River water upstream of the city has been used for this recharging for many years. There is a good correlation between the metal content in the investigated samples and in the water. In the muscles, only Cd, Co and Mn, in the liver Cd, Co, Cr. Hg, Mn and Zn, and in the total fish Cd, Co, Cr, Cu and Zn had increased significantly. In contrast to all other elements, Cr shows the highest concentration in the muscles. A previous accumulation of Cr in the liver is not a prerequisite for the accumulation in the muscles. Mercury shows the highest accumulation in the muscles, apparently because of the high retention rate of this element. Muscles also are a good monitor for this element. The impact of heavy metals on the Leine water was reflected in aquatic plants, which showed an increase in concentration up to 95-fold (according to metal or plant) - but not in river-bank plants. C. glomerata has the remarkable capability of accumulating all ten elements. Since P. arundinacea cannot reflect the different load of heavy metals it is therefore less suitable as a biological monitor for these metals.

  18. Genome-wide analysis of pentatricopeptide-repeat proteins of an aquatic plant.

    Science.gov (United States)

    Wang, Wenqin; Wu, Yongrui; Messing, Joachim

    2016-10-01

    A large proportion of genes in plant genomes are organized as gene families. Whereas most gene families in the aquative plant Spirodela are reduced in their copy number, the PPR gene family is expanded, which match the RNA editing sites in organelles, providing us with new insights in the evolution of flowering plants. Pentatricopeptide-repeat proteins (PPRs) are nuclear-encoded proteins that are targeted to mitochondria and plastids to stabilize and edit mRNA transcribed from organellar genomes. They have been described for many terrestrial plant species from a diverse spectrum of sequenced genomes. To further increase our understanding of the evolution of this gene family across angiosperms, we analyzed the PPR genes in the aquatic species Spirodela polyrhiza in the order of the Alismatales (monocotyledonous plants). Because we had generated next generation sequencing data from transcripts and had sequenced the genome of Spirodela polyrhiza, we were able to identify its PPR genes and determine the level of their expression. In total, we could identify 556 PPR proteins, of which 238 members belong to the P (P motif) subfamily that is mainly involved in RNA stabilization and 318 ones to the PLS (P, Longer P, shorter P motif) subfamily responsible for RNA editing. Compared to other angiosperms, this is a large increase in the copy number of the PLS-PPRs subfamily and the expansion correlates with the increase of the number of RNA editing sites of organellar transcripts. Expression of PPR was generally stable even during growing and dormant stages, indicating that their function was critical throughout development. However, PPRs, especially those of the PLS subfamily, were expressed at relatively low levels, suggesting a delicate fine-tuning of its trans-acting function in the post-transcriptional regulation of gene expression. Thus, understanding PPR evolution and expression will help decipher the PPR code for their binding sites, which could genetically engineer

  19. Molecular adaptation of rbcL in the heterophyllous aquatic plant Potamogeton.

    Directory of Open Access Journals (Sweden)

    Satoko Iida

    Full Text Available BACKGROUND: Heterophyllous aquatic plants show marked phenotypic plasticity. They adapt to environmental changes by producing different leaf types: submerged, floating and terrestrial leaves. By contrast, homophyllous plants produce only submerged leaves and grow entirely underwater. Heterophylly and submerged homophylly evolved under selective pressure modifying the species-specific optima for photosynthesis, but little is known about the evolutionary outcome of habit. Recent evolutionary analyses suggested that rbcL, a chloroplast gene that encodes a catalytic subunit of RuBisCO, evolves under positive selection in most land plant lineages. To examine the adaptive evolutionary process linked to heterophylly or homophylly, we analyzed positive selection in the rbcL sequences of ecologically diverse aquatic plants, Japanese Potamogeton. PRINCIPAL FINDINGS: Phylogenetic and maximum likelihood analyses of codon substitution models indicated that Potamogeton rbcL has evolved under positive Darwinian selection. The positive selection has operated specifically in heterophyllous lineages but not in homophyllous ones in the branch-site models. This suggests that the selective pressure on this chloroplast gene was higher for heterophyllous lineages than for homophyllous lineages. The replacement of 12 amino acids occurred at structurally important sites in the quaternary structure of RbcL, two of which (residue 225 and 281 were identified as potentially under positive selection. CONCLUSIONS/SIGNIFICANCE: Our analysis did not show an exact relationship between the amino acid replacements and heterophylly or homophylly but revealed that lineage-specific positive selection acted on the Potamogeton rbcL. The contrasting ecological conditions between heterophyllous and homophyllous plants have imposed different selective pressures on the photosynthetic system. The increased amino acid replacement in RbcL may reflect the continuous fine-tuning of Ru

  20. Microbial plant litter decomposition in aquatic and terrestrial boreal systems along a natural fertility gradient

    Science.gov (United States)

    Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

    2017-04-01

    Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal

  1. Hematoxylin staining technique to locate sites of aluminium binding in aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Havas, M.

    1986-10-01

    This paper describes a modified hematoxylin staining technique that can be used to locate sites of Al binding in freshwater plants and animals. This technique is fast, simple, and inexpensive to use. It is more reliable for organisms raised under controlled conditions, although it can be used on organisms isolated from the field. In the presence of Al, a purple stain appears which absorbs between 560 and 570 nm. This stain can be used as a live stain over the pH range of 3 to 9. The stain remains stable for at least 12 mo in alcohol-preserved specimens. Low concentrations of Fe (reddish-brown) and high concentrations of Pb (grey) and Cu (pink) can mask the reaction with Al (purple). Fluoride (10:1 molar ratio to Al), EDTA (1:1 ratio to Al), humic acid and PO/sub 4/ (1:10 ratio to Al) can prevent Al uptake or interfere with Al-hematein binding. Based on the technique described in this paper, sites of Al binding in aquatic plants and animals include: nucleus and cell wall of the green alga Mougeotia; cell wall of the aquatic moss Leptodictyum riparium; chloride cells, tip of the penis, and hind gut of the fairy shrimp, Branchinecta paludosa; and the anal papillae of the phantom midge, Chaoborus. 16 references.

  2. A hematoxylin staining technique to locate sites of aluminium binding in aquatic plants and animals

    Energy Technology Data Exchange (ETDEWEB)

    Havas, M.

    1986-10-01

    A modified hematoxylin staining technique that can be used to locate sites of Al binding in freshwater plants and animals is described. This technique is fast, simple, and inexpensive to use. It is more reliable for organisms raised under controlled conditions, although it can be used on organisms isolated from the field. In the presence of Al, a purple stain appears which absorbs between 560 and 570 nm. This stain can be used as a live stain over the pH range of 3 to 9. The stain remains stable for at least 12 mo in alcohol-preserved specimens. Low concentrations of Fe (reddish-brown) and high concentrations of Pb (grey) and Cu (pink) can mask the reaction with Al (purple). Fluoride (10:1 molar ratio to Al), EDTA (1:1 ratio to Al), humic acid and PO/sub 4/ (1:10 ratio to Al) can prevent Al uptake or interfere with Al-hematein binding. Based on the technique described in this paper, sites of Al binding in aquatic plants and animals include: nucleus and cell wall of the green alga Mougeotia; cell wall of the aquatic moss Leptodictyum riparium; chloride cells, tip of the penis, and hind gut of the fairy shrimp, Branchinecta paludosa; and the anal papillae of the phantom midge, Chaoborus. 16 refs.

  3. The utilization of emergent aquatic plants for biomass-energy-systems development

    Science.gov (United States)

    Kresovich, S.; Wagner, C. K.; Scantland, D. A.; Groet, S. S.; Lawhon, W. T.

    1982-02-01

    A review was conducted of the available literature pertaining to the following aspects of emergent aquatic biomass: identification of prospective emergent plant species for management; evaluation of prospects for genetic manipulation; evaluation of biological and environmental tolerances; examination of current production technologies; determination of availability of seeds and/or other propagules, and projections for probable end-uses and products. Species identified as potential candidates for production in biomass systems include Arundo donax, Cyperus papyrus, Phragmites communis, Saccharum spontaneum, Spartina alterniflora, and Typha latifolia. If these species are to be viable candidates in biomass systems, a number of research areas must be further investigated. Points such as development of baseline yield data for managed systems, harvesting conceptualization, genetic (crop) improvement, and identification of secondary plant products require refinement.

  4. Professor Kalkman retires

    NARCIS (Netherlands)

    Baas, Pieter

    1991-01-01

    On 13 December 1990 Prof. Dr. Cornelis (Kees) Kalkman retired from the positions of Professor of Plant Systematics and Scientific Director of the Rijksherbarium/ Hortus Botanicus by presenting his valedictory lecture to the academic community of Leiden University and the assembled Dutch Botanical

  5. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

    Science.gov (United States)

    Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. © 2012 Blackwell Publishing Ltd.

  6. Design and analysis of aquatic monitoring programs at nuclear power plants.

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Kannberg, L.D.; Gore, K.L.; Arnold, E.M.; Watson, D.G.

    1977-11-01

    This report addresses some of the problems of designing, conducting, and analyzing aquatic environmental monitoring programs for impact assessment of nuclear power plants. The concepts discussed are applicable to monitoring the effects of chemical, radioactive, or thermal effluents. The concept of control and treatment station pairs is the fundamental basis for the experimental method proposed. This concept is based on the hypothesis that the relationship between the two stations forming the pair can be estimated from the preoperational period and that this relationship holds during the operational period. Any changes observed in this relationship during the operational period are assumed to be the result of the power plant impacts. Thus, it is important that station pairs are selected so it can be assumed that they respond to natural environmental changes in a manner that maintains that relationship. The major problem in establishing the station pairs will be the location of the control station. The universal heterogeneity in the environment will prevent the establishment of identical station pairs. The requirement that the control station remain unaffected by the operation of the power plant dictates a spacial separation with its associated differences in habitat. Thus, selection of the control station will be based upon balancing the following two criteria: (1) far enough away from the plant site to be beyond the plant influence, and (2) close enough to the treatment station that the biological communities will respond to natural environmental changes consistently in the same manner.

  7. Fate of methane in aquatic systems dominated by free-floating plants.

    Science.gov (United States)

    Kosten, Sarian; Piñeiro, Marcia; de Goede, Eefje; de Klein, Jeroen; Lamers, Leon P M; Ettwig, Katharina

    2016-11-01

    Worldwide the area of free-floating plants is increasing, which can be expected to alter methane (CH 4 ) emissions from aquatic systems in several ways. A large proportion of the CH 4 produced may become oxidized below the plants due to the accumulation of CH 4 as a result of a decrease in the diffusive water-atmosphere flux and the entrapment of part of the ebullitive CH 4 , in combination with suitable conditions for methane oxidizing (MOX) bacteria in the aerobic rhizosphere. We used a set of essays to test this hypothesis and to explore the effect of different densities for three widespread free-floating species: Azolla filiculoides, Salvinia natans, and Eichhornia crassipes. The gas exchange velocity, proportion of CH 4 bubbles trapped by the plants, occurrence of radial oxygen loss from roots, and MOX rates on the roots were assessed. We subsequently used the outcome of these experiments to parameterize a simple model. With this model we estimated the proportion of the produced CH 4 that is oxidized, for different plant species and different densities. We found that in a shallow (1 m) system up to 70% of the CH 4 produced may become oxidized as a result of a strong decrease in gas exchange combined with high MOX activity of the rhizosphere microbiome. As floating plants also are likely to increase CH 4 production by organic matter production, especially when their presence induces anaerobic conditions, the overall effect on CH 4 emission will strongly depend on local conditions. This explains the contrasting effects of floating plants on CH 4 emissions in literature as reviewed here. As the effect of floating plants on CH 4 emissions, including the high MOX rates we show here, can be substantial, there is an urgent need to consider this impact when assessing greenhouse gas budgets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Do Varying Aquatic Plant Species Affect Phytoplankton and Crustacean Responses to a Nitrogen-Permethrin Mixture?

    Science.gov (United States)

    Lizotte, Richard E; Moore, Matthew T

    2017-01-01

    Hydraulically connected wetland microcosms vegetated with either Typha latifolia or Myriophyllum aquaticum were amended with an NH4NO3 and permethrin mixture to assess the effectiveness of both plant species in mitigating effects of the pollutant mixture on phytoplankton (as chlorophyll a) and Hyalella azteca. Phytoplankton grew in response to increased NH4NO3 in the presence of all plant species, but was unaffected by exposure to permethrin. H. azteca responses occurred rapidly (0.17 days), was mitigated within 1-2 days, and aqueous toxicity was unaffected by plant species type. A toxic unit model approach ascertained primary toxicity was permethrin with minimal additional toxicity from NH4NO3. Varying aquatic plant species had only modest influences on phytoplankton responses and no observable influence on animal responses during nitrogen-permethrin mixture exposures. As a result, both T. latifolia and M. aquaticum can be used as part of an effective agricultural best-management practice system for mitigating pollutant impacts of agricultural run-off.

  9. Development and validation of phytotoxicity tests with emergent and submerged aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.S. [Carolina Ecotox, Inc., Durham, NC (United States); Powell, R.L. [Monsanto Co., St. Louis, MO (United States); Nelson, M.K. [National Biological Service, Columbia, MO (United States)

    1995-12-31

    Toxicity testing procedures have recently been developed for assessment of contaminant effects on emergent and submerged aquatic macrophytes commonly found in freshwater wetlands. These tests have potential application in risk assessments for contaminated wetlands as well as for new chemical substances. The objective of this study was to evaluate and modify, if necessary, these methods and to validate them, using two benchmark chemicals, in a contract laboratory setting. Oryza sativa (domestic rice) was used as a surrogate emergent vascular plant, while Ceratophylium demersum (coontail) and Myriophyllum heterophyllum (variable-leaf milfoil) were the representative submerged vascular plants. Subsequent to evaluating culturing techniques and testing conditions, toxicity tests were conducted using boron and metribuzin. The test procedure for the emergent plants involves a two-week pro-exposure period followed by a two-week aqueous exposure. Five types of sediment, including both natural and artificial sediments, were evaluated for use with rice. Fresh weight and chlorophyll a content were the selected test endpoints. The submerged plants were exposed for two weeks, and the response variables evaluated included length, weight (fresh and dry), and root number. The sensitivity of these tests were comparable to the results obtained for the same two chemicals using the green alga, Selenastrum capricornutum, and the duckweed, Lemna gibba, with the exception that rice was less sensitive to metribuzin than the other species.

  10. Internal nitrogen removal from sediments by the hybrid system of microbial fuel cells and submerged aquatic plants.

    Science.gov (United States)

    Xu, Peng; Xiao, En-Rong; Xu, Dan; Zhou, Yin; He, Feng; Liu, Bi-Yun; Zeng, Lei; Wu, Zhen-Bin

    2017-01-01

    Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs) with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o), closed-circuit (SMFC-c), aquatic plants with open-circuit (P-SMFC-o) and aquatic plants with closed-circuit (P-SMFC-c). The changes in the bio-electrochemical characteristics of the nitrogen levels in overlying water, pore water, sediments, and aquatic plants were documented to explain the migration and transformation pathways of internal nitrogen. The results showed that both electrogenesis and aquatic plants could facilitate the mineralization of organic nitrogen in sediments. In SMFC, electrogenesis promoted the release of ammonium from the pore water, followed by the accumulation of ammonium and nitrate in the overlying water. The increased redox potential of sediments due to electrogenesis also contributed to higher levels of nitrate in overlying water when nitrification in pore water was facilitated and denitrification at the sediment-water interface was inhibited. When the aquatic plants were introduced into the closed-circuit SMFC, the internal ammonium assimilation by aquatic plants was advanced by electrogenesis; nitrification in pore water and denitrification in sediments were also promoted. These processes might result in the maximum decrease of internal nitrogen with low nitrogen levels in the overlying water despite the lower power production. The P-SMFC-c reduced 8.1%, 16.2%, 24.7%, and 25.3% of internal total nitrogen compared to SMFC-o on the 55th, 82th, 136th, and 190th days, respectively. The smaller number of Nitrospira and the larger number of Bacillus and Pseudomonas on the anodes via high throughput sequencing may account for strong mineralization and denitrification in the sediments

  11. Internal nitrogen removal from sediments by the hybrid system of microbial fuel cells and submerged aquatic plants.

    Directory of Open Access Journals (Sweden)

    Peng Xu

    Full Text Available Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o, closed-circuit (SMFC-c, aquatic plants with open-circuit (P-SMFC-o and aquatic plants with closed-circuit (P-SMFC-c. The changes in the bio-electrochemical characteristics of the nitrogen levels in overlying water, pore water, sediments, and aquatic plants were documented to explain the migration and transformation pathways of internal nitrogen. The results showed that both electrogenesis and aquatic plants could facilitate the mineralization of organic nitrogen in sediments. In SMFC, electrogenesis promoted the release of ammonium from the pore water, followed by the accumulation of ammonium and nitrate in the overlying water. The increased redox potential of sediments due to electrogenesis also contributed to higher levels of nitrate in overlying water when nitrification in pore water was facilitated and denitrification at the sediment-water interface was inhibited. When the aquatic plants were introduced into the closed-circuit SMFC, the internal ammonium assimilation by aquatic plants was advanced by electrogenesis; nitrification in pore water and denitrification in sediments were also promoted. These processes might result in the maximum decrease of internal nitrogen with low nitrogen levels in the overlying water despite the lower power production. The P-SMFC-c reduced 8.1%, 16.2%, 24.7%, and 25.3% of internal total nitrogen compared to SMFC-o on the 55th, 82th, 136th, and 190th days, respectively. The smaller number of Nitrospira and the larger number of Bacillus and Pseudomonas on the anodes via high throughput sequencing may account for strong mineralization and denitrification in the

  12. Silver nanoparticles induced reactive oxygen species via photosynthetic energy transport imbalance in an aquatic plant.

    Science.gov (United States)

    Jiang, Hong Sheng; Yin, Li Yan; Ren, Na Na; Zhao, Su Ting; Li, Zhi; Zhi, Yongwei; Shao, Hui; Li, Wei; Gontero, Brigitte

    2017-03-01

    The rapid growth in silver nanoparticles (AgNPs) commercialization has increased environmental exposure, including aquatic ecosystem. It has been reported that the AgNPs have damaging effects on photosynthesis and induce oxidative stress, but the toxic mechanism of AgNPs is still a matter of debate. In the present study, on the model aquatic higher plant Spirodela polyrhiza, we found that AgNPs affect photosynthesis and significantly inhibit Photosystem II (PSII) maximum quantum yield (F v /F m ) and effective quantum yield (Φ PSII ). The changes of non-photochemical fluorescence quenching (NPQ), light-induced non-photochemical fluorescence quenching [Y(NPQ)] and non-light-induced non-photochemical fluorescence quenching [Y(NO)] showed that AgNPs inhibit the photo-protective capacity of PSII. AgNPs induce reactive oxygen species (ROS) that are mainly produced in the chloroplast. The activity of ribulose-1, 5-bisphosphate carboxylase-oxygenase (Rubisco) was also very sensitive to AgNPs. The internalized Ag, regardless of whether the exposure was Ag +  or AgNPs had the same capacity to generate ROS. Our results support the hypothesis that intra-cellular AgNP dissociate into high toxic Ag + . Rubisco inhibition leads to slowing down of CO 2 assimilation. Consequently, the solar energy consumption decreases and then the excess excitation energy promotes ROS generation in chloroplast.

  13. Comparative Studies on Effects of Acid Solutions on Aquatic Plants by Beam Deflection and Absorbance Spectroscopy Methods.

    Science.gov (United States)

    Wu, Xing-Zheng; Nie, Liangjiao; Inoue, Tomomi

    2015-01-01

    The beam deflection method and absorbance spectroscopy were applied to study effects of acid solutions on aquatic plants, and their results were compared. Aquatic plants Egeria densa and Ceratophyllum demersum L were used as model plants. In absorbance experiments, a piece of the plants was put in a beaker with 20 mL HCl solution, and absorbance of the HCl solution was measured every 30 min. In beam deflection experiments, a probe beam from a He-Ne laser was focused to a vicinity of the plants in a culture dish with HCl solution by an objective lens, and deflection signals of the probe beam were monitored by a position sensor. Absorbance spectra of the HCl solutions with immersing of the plants showed absorbance below 410 nm, suggesting that some compounds leaked from the plants into the HCl solutions. Changes of absorbance and deflection signals with immersion time were examined for different pH levels. The changing trends of the absorbance and deflection signals with time were similar, but the absorbance changes were delayed for about 2 - 3 h. The absorbance method could not detect the effect of the pH 5.0 HCl solutions on the aquatic plants, while the deflection method could.

  14. Compensatory growth in an aquatic plant mediates exploitative competition between seasonally tied herbivores.

    Science.gov (United States)

    Hidding, Bert; Nolet, Bart A; De Boer, Thujs; De Vries, Peter P; Klaassen, Marcel

    2009-07-01

    The degree to which vertebrate herbivores exploitatively compete for the same food plant may depend on the level of compensatory plant growth. Such compensation is higher when there is reduced density-dependent competition in plants after herbivore damage. Whether there is relief from competition may largely be determined by the life-history stage of plants under herbivory. Such stage-specific compensation may apply to seasonal herbivory on the clonal aquatic plant sago pondweed (Potamogeton pectinatus L.). It winters in sediments of shallow lakes as tubers that are foraged upon by Bewick's Swans (Cygnus columbianus bewickii Yarrell), whereas aboveground biomass in summer is mostly consumed by ducks, coots, and Mute Swans. Here, tuber predation may be compensated due to diminished negative density dependence in the next growth season. However, we expected lower compensation to summer herbivory by waterfowl and fish as density of aboveground biomass in summer is closely related to photosynthetic carbon fixation. In a factorial exclosure study we simultaneously investigated (1) the effect of summer herbivory on aboveground biomass and autumn tuber biomass and (2) the effect of tuber predation in autumn on aboveground biomass and tuber biomass a year later. Summer herbivory strongly influenced belowground tuber biomass in autumn, limiting food availability to Bewick's Swans. In contrast, tuber predation in autumn by Bewick's Swans had a limited and variable effect on P. pectinatus biomass in the following growth season. Whereas relief from negative density dependence largely eliminates effects of belowground herbivory by swans, aboveground herbivory in summer limits both above- and belowground plant biomass. Hence, there was an asymmetry in exploitative competition, with herbivores in summer reducing food availability for belowground herbivores in autumn, but not the other way around.

  15. Microsatellite markers for Nuphar japonica (Nymphaeaceae), an aquatic plant in the agricultural ecosystem of Japan1

    Science.gov (United States)

    Kondo, Toshiaki; Watanabe, Sonoko; Shiga, Takashi; Isagi, Yuji

    2016-01-01

    Premise of the study: Nuphar species (Nymphaeaceae) are representative aquatic plants in irrigation ponds in Japanese agricultural ecosystems. We developed 15 polymorphic microsatellite markers for N. japonica and confirmed their utility for its close relatives N. oguraensis var. akiensis and N. ×saijoensis, which originated from natural hybridization between N. japonica and N. oguraensis. Methods and Results: Genetic variation was characterized in 15 polymorphic loci in three populations of N. japonica. The average number of alleles per locus was 3.47 (range = 2−9; n = 32), and the average expected heterozygosity per locus was 0.84 (range = 0.5–1.0); 11 loci were amplified in N. oguraensis var. akiensis and 15 in N. ×saijoensis. Conclusions: The polymorphic microsatellite markers developed in this study will be useful for investigating the levels of genetic diversity within remnant populations of Nuphar taxa and could provide a valuable tool for conservation genetics of these taxa. PMID:28101435

  16. Effects of acidification on metal accumulation by aquatic plants and invertebrates. 1. Constructed wetlands

    Science.gov (United States)

    Albers, P.H.; Camardese, M.B.

    1993-01-01

    The pH of lake water is often inversely correlated with concentrations of trace metals in the water column. Concentrations of Al, Cd, Ca, Cu, Fe, Hg, Pb, Mg, Mn, Ni, P, and Zn were compared in water, plants, and aquatic insects from three acidified (pH 5.0) and three nonacidified (pH 6.5) constructed wetlands. Concentrations of Zn in water and bur-reed (Sparganium americanum) were higher in acidified wetlands than in nonacidified wetlands. Floating nonrooted plants contained mean concentrations of Fe, Mg, and Mn that were higher than recommended maximum levels for poultry feed. The mean concentrations of all metals in insects were below recommended maximum levels for poultry feed and below levels that cause toxic effects in wild birds. Smaller than expected increases of metal concentrations in the water of acidified wetlands were probably due to limited mobilization of metals from the sediments and insignificant changes in sedimentation of aqueous metals. Calcium was lower in acidified than in nonacidified wetland water, but the Ca content of insects and bur-reed was not lower. Low concentrations of Ca in aquatic insects from both groups of wetlands indicate that calcium-rich crustaceans and mollusks are probably important to female waterfowl and their young during the spring, when invertebrates make up the majority of the diet. Although toxic effects from metal ingestion seem to be unlikely consequences of wetland acidification, the adverse effect of low pH on the occurrence of crustaceans and mollusks could threaten egg production and development of young.

  17. Effects of long-term radiation exposure on the higher aquatic plants in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Shevtsova, N.; Gudkov, D. [Institute of Hydrobiology (Russian Federation)

    2014-07-01

    From the earliest years after the Chernobyl accident in 1986 the radioecological study on freshwater plant communities in the water-bodies within the Chernobyl exclusion zone (ChEZ) has been held. At first stages it was the research on plant species collection and radionuclide contamination of aquatic ecosystems. Now, it is the seasonal monitoring with several groups of data deals with different areas of plant communities investigation: (1) the data characterized the level of radionuclides contamination of the abiotic and biotic components of phyto-coenosis and connected absorbed dose rates for various species of aquatic plants; (2) indexes of plant reproduction, including productivity, sterility, seed germination indexes and different abnormalities of ontogenesis; (3) indexes of morphological deviations (radiomorphoses) of aquatic plant's reproduction organs such as panicle and seeds; (4) cytogenetic indexes including the rate and spectrum of chromosome aberrations in cells of apical root meristem of air-aquatic plants; (5) the group of indexes, connected with plant's immunity. The calculated absorbed dose rate for littoral emergent plants in sampling water bodies was varied from 0.7 to 1.4 Gy/year in dependence of radioactive contamination of bottom sediments, plant tissues and level of gamma-background. There were registered rather low rate of plant productivity (hundred times lower than normal), high percentage of sterility (20-80%), low germinating ability (14-48 %) and germinating power (40-50%) of seeds from all sampling water bodies within the ChEZ. Against the general suppressed background the effect of relative stimulation of more affected seeds was observed. With increase of internal absorbed dose in range of 0.2-5.3 mGy/year the number of germinated seeds was increased. At the same time the number of different abnormalities of seeds was increased as well. The highest rate of the morphological damages (up to 25 % of the total number of

  18. Removal of high organic loads from winery wastewater by aquatic plants.

    Science.gov (United States)

    Zimmels, Y; Kirzhner, F; Schreiber, J

    2008-09-01

    Laboratory- and field-scale purification tests of raw and diluted winery wastewater (WWW) were carried out using aquatic plants at high organic loads. The laboratory tests were performed using artificial light at 1800 to 1900 lux. The objective of the current study was to define the potential of floating and emergent aquatic macrophytes and the microorganisms attached to their roots, to reduce high organic loads that characterize WWW, thereby providing, for these effluents, an effective treatment and management system. These microorganisms are believed to have a major role in the treatment process. In this context, the potential of floating and emergent macrophytes to improve the water quality of raw compared with diluted WWW was evaluated. In raw WWW (chemical oxygen demand [COD] 5.6 g/L),growth inhibition of both water hyacinth (Eichhornia crassipes) and water pennywort (Hydrocotyle umbellata) was observed. A 1:1 dilution of WWW with fresh (tap) water facilitated growth of these plants. At this dilution level, growth of pennywort was limited, while that of water hyacinth was robust. In terms of reductions in biochemical oxygen demand, COD, and total suspended solids, both water hyacinth and pennywort performed better in diluted compared with raw WWW. At 1:1 and 1:3 dilution, 95.9 to 97% of the COD was removed after 23 days, in the presence of Hydrocotyle and Eichhornia plants and aeration. The capacity of new emergent plants to remove high organic loads from WWW, at enhanced kinetics, was demonstrated. This unique property was tested and compared with the role of the gravel media that support growth of the high-capacity emergent plants. In the presence of reed and salt marsh plants, 83 to 99% of the COD was removed within a period of 24 to 29 days, at 1.5:1 dilution. The new emergent plants proved to be effective, even at record high levels of COD. At an initial level of 16,460 mg/L, the COD was brought down to 2870 mg/L after 24 days (82.6% removal), while 12

  19. Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

    NARCIS (Netherlands)

    Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

    Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

  20. Utilizing next generation sequencing to characterize microsatellite loci in a tropical aquatic plant species Cryptocoryne cordata var. cordata (Araceae)

    DEFF Research Database (Denmark)

    Rosazlina, Rusly; Jacobsen, Niels; Ørgaard, Marian

    2015-01-01

    Abstract Cryptocoryne cordata var. cordata (2n = 34) is an aquatic plant species distributed from the southern part of Peninsular Thailand through the Malay Peninsula. It propagates both sexually and asexually via stolons. The current study is aimed at developing nuclear microsatellite markers...

  1. Why are most aquatic plants widely distributed? Dispersal, clonal growth and small-scale heterogeneity in a stressful environment

    NARCIS (Netherlands)

    Santamaria, L.

    2002-01-01

    Non-marine aquatic vascular plants generally show broad distributional ranges. Climatic factors seem to have limited effects on their distributions, besides the determination of major disjunctions (tropical-temperate-subarctic). Dispersal should have been frequent enough to assure the quick

  2. Diversity of Endophytic Fungi Associated with the Roots of Four Aquatic Plants Inhabiting Two Wetlands in Korea.

    Science.gov (United States)

    You, Young-Hyun; Park, Jong Myong; Park, Jong-Han; Kim, Jong-Guk

    2015-09-01

    A total of 4 aquatic plants, Eleocharis kuroguwai Ohwi, Hydrocharis dubia Backer, Salvinia natans All., and Zizania latifolia Turcz., were sampled from representative two wetlands of South Korea. A total of 38 endophytic fungal strains were isolated from aquatic plants native to the Daepyeong wetland, and 27 strains were isolated from the Jilnal wetland. The internal transcribed spacer regions of fungal isolates were sequenced and a phylogenetic analysis was performed. In addition, endophytic fungal diversity from each wetland and host plant species was deduced. A total of 25 fungal genera were purely isolated, and 16 fungal genera were isolated from each of the two wetlands. Commonly isolated genera from both wetlands were Aspergillus, Cladosporium, Clonostachys, Fusarium, Leptosphaeria, Penicillium, and Talaromyces. This study revealed that fungal diversity varied with environmental conditions and by host plant in representative two wetlands.

  3. Effect of mercury on some aquatic plants. [Hydrilla verticillata Presl. ; Pistia stratiotes L. ; Salvinia molesta D. S. Mitchell

    Energy Technology Data Exchange (ETDEWEB)

    Mhatre, G.N.; Chaphekar, S.B.

    1985-01-01

    Three aquatic plants, Hydrilla verticillata Presl, Pistia stratiotes L. and Salvinia molesta D.S. Mitchell, were treated with different concentrations of mercury ranging from 1 to 1000 ..mu..g liter/sup -1/ at three different exposure durations, i.e. 1, 3 and 5 h. All were found to be severely affected by mercury. Foliar injury, chlorophyll content and phytomass showed perceptible effects with increasing exposure to the metal. In the case of floating plants a positive relationship was obtained between Leaf Injury Index (LII) and doses of the metal. The possible use of aquatic plants in general, and floating plants in particular, as simple bioassay material in biomonitoring and toxicity studies is discussed with special reference to LII as a simple biomonitoring parameter.

  4. Potential accumulation of estrogenic substances in biofilms and aquatic plants collected in sewage treatment plant (STP) and receiving water

    Energy Technology Data Exchange (ETDEWEB)

    Schultis, T.; Kuch, B.; Kern, A.; Metzger, J.W. [Inst. for Sanitary Engineering, Water Quality and Solid Waste Management ISWA, Stuttgart Univ. (Germany)

    2004-09-15

    During the past years the estrogenic potency of natural (e.g. estrone and 17{beta}-estradiol E2) and synthetic hormones (e.g. ethinylestradiol EE2) and xenoestrogens (e.g. pesticides, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dioxins (PCDDs) and furans (PCDFs), alkylphenolic compounds or bisphenol A (BPA)) has attracted increasing scientific attention. Especially the occurrence and behaviour of these substances in waste water of sewage treatment plants (STPs) were often investigated. Andersen et al. found steroid estrogen concentrations in the effluent of a municipal STP always below the limit of quantification of 1 ng/l. However, Aerni et al. detected E2 and EE2 concentrations up to 6 ng/l and 2 ng/l, and alkylphenols, alkylphenolmonoand diethoxylates even at {mu}g/l concentrations in the effluent of a wastewater treatment plant with a significant industrial impact3. In activated and digested sewage sludge concentrations of estrone and E2 up to 37 ng/g and 49 ng/g, of the synthetic EE2 up to 17 ng/g were observed4. In river sediments the concentrations detected were lower with up to 2 ng/g estrone and 0,9 ng/g EE24. In the meantime many studies exist about raw and treated water in STPs, but there is little knowledge about the influence of estrogenic active substances on aquatic plants so far. In this study we investigated therefore the potency of estrogenic substances to accumulate in the duckweed Lemna minor from STP in comparison to the estrogenicity of duckweed from a natural pond, biofilms in drain and microsieve of the STP by the in vitro E-Screen- and LYES-assay (yeast estrogen screen-assay assisted by enzymatic digestion with lyticase). In addition, we tested the estrogenic activity of moss-like aquatic plants collected at different sites of the receiving water and analyzed the concentrations of four phenolic xenoestrogens in the effluent by GC/MS.

  5. Traits of fatty acids composition of surface lipids of some aquatic plants under the influence of pollutants

    Directory of Open Access Journals (Sweden)

    І. О. Alexeevs’ka

    2007-12-01

    Full Text Available It was shown that some emergent aquatic plants may be used for treatment of waste waters. The plants have specific composition of surface lipids (SL. The SL composition was found to be changed under the influence of water pollutants. These changes concerned the processes of elongation and desaturation of the SL components. The response to contamination was specific for each species.

  6. Heavy metals in sediments, soils, and aquatic plants from a secondary anabranch of the three gorges reservoir region, China.

    Science.gov (United States)

    Gao, Jun-Min; Sun, Xiu-Qian; Jiang, Wen-Chao; Wei, Yun-Mei; Guo, Jin-Song; Liu, Yuan-Yuan; Zhang, Ke

    2016-06-01

    We investigated the occurrence of cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), Znic (Zn), iron (Fe), manganese (Mn), and magnesium (Mg) in sediments, as well as in related soils and aquatic plants in the Liangtan River, a typical secondary anabranch of the Yangtze River in the Three Gorges Reservoir Region (TGRR) of China. We found that sediments accumulated more metals than soils and aquatic plants. Concentrations of the nine metals in sediments and soils followed the same sequence, while their concentrations in aquatic plants followed a different sequence. Potential adverse effects of contaminated sediments on benthic fauna were evaluated, and the results showed that the toxic effect on benthic organisms followed the sequence Zn > Ni > Cr > Cu > Cd > Pb. The potential ecological risk index analysis indicated that Cd in sediments had considerable ecological risk, whereas Cr, Cu, Zn, Ni, and Pb had low ecological risk. The potential ecological risk index (RI) of the heavy metals in sediments of the Liangtan River was 174.9, indicating moderate ecological risk. The transfer factor trend of metals for aquatic plants showed that Cd and Ni had the most and least accumulation, respectively. For Cu, Cd, Mg, Pb, and Cr, a significant positive correlation of the metal concentrations was observed between sediments and soils, but no correlations (excluding Cr) were detected between sediments and aquatic plants. Our study indicated that anthropogenic input may be the primary source of metal contamination in the Liangtan River, and that Zn and Cd pollution in the Liangtan River should be further explored.

  7. Effects of cement flue dust from a cement factory on stress parameters and diversity of aquatic plants.

    Science.gov (United States)

    Erdal, Serkan; Demirtas, Ayten

    2010-07-01

    Cement kiln dusts, made of a complex mixture of elements, include high levels of heavy metals such as fluoride, magnesium, lead, cadmium, nickel, zinc, copper, beryllium and some toxic compounds. Because of the toxic element compositions and radioactive isotope properties of cement kiln dusts, not only terrestrial but also aquatic ecosystems are subjected to greater stress. In the present paper, we investigated the effects of pollution caused by Askale-Erzurum cement factory (CF) on the stress parameters and diversity of aquatic plants. For this purpose, aquatic plant species were collected from the outer zone of the CF. Only three (Lemna minor, Ceratophyllum submersum and Potamogeton natans) of these species were able to be determined in the CF zone. Antioxidant enzyme activities of the collected aquatic plants were measured and compared to their controls. Superoxide dismutase (SOD) activity of P. natans in the CF zone was significantly high compared to their respective control, while it was low in L. minor and C. submersum compared to their controls. Similarly, peroxidase (POX) activity of P. natans was high, while those of L. minor and C. submersum were low compared to their respective controls. On the other side, while catalase (CAT) activities of L. minor and C. submersum were low, that of P. natans did not show an important change compared to their respective controls. Furthermore, we found that hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) levels of all the studied plants were also very high compared to their controls. According to these results, it is clear that pollution caused by the CF reduced diversity and number of aquatic plant species. Besides, the obtained data revealed that P. natans have a more resistant defense system than other species.

  8. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

  9. Clonal Plasticity of Aquatic Plant Species Submitted to Mechanical Stress: Escape versus Resistance Strategy

    Science.gov (United States)

    Puijalon, Sara; Bouma, Tjeerd J.; Van Groenendael, Jan; Bornette, Gudrun

    2008-01-01

    Background and Aims The plastic alterations of clonal architecture are likely to have functional consequences, as they affect the spatial distribution of ramets over patchy environments. However, little is known about the effect of mechanical stresses on the clonal growth. The aim of the present study was to investigate the clonal plasticity induced by mechanical stress consisting of continuous water current encountered by aquatic plants. More particularly, the aim was to test the capacity of the plants to escape this stress through clonal plastic responses. Methods The transplantation of ramets of the same clone in two contrasting flow velocity conditions was carried out for two species (Potamogeton coloratus and Mentha aquatica) which have contrasting clonal growth forms. Relative allocation to clonal growth, to creeping stems in the clonal biomass, number and total length of creeping stems, spacer length and main creeping stem direction were measured. Key Results For P. coloratus, plants exposed to water current displayed increased total length of creeping stems, increased relative allocation to creeping stems within the clonal dry mass and increased spacer length. For M. aquatica, plants exposed to current displayed increased number and total length of creeping stems. Exposure to current induced for both species a significant increase of the proportion of creeping stems in the downstream direction to the detriment of creeping stems perpendicular to flow. Conclusions This study demonstrates that mechanical stress from current flow induced plastic variation in clonal traits for both species. The responses of P. coloratus could lead to an escape strategy, with low benefits with respect to sheltering and anchorage. The responses of M. aquatica that may result in a denser canopy and enhancement of anchorage efficiency could lead to a resistance strategy. PMID:18854376

  10. Multiple mitigation mechanisms: Effects of submerged plants on the toxicity of nine insecticides to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2017-01-01

    Understanding the processes that regulate contaminant impacts in nature is an increasingly important challenge. For insecticides in surface waters, the ability of aquatic plants to sorb, or bind, hydrophobic compounds has been identified as a primary mechanism by which toxicity can be mitigated (i.e. the sorption-based model). However, recent research shows that submerged plants can also rapidly mitigate the toxicity of the less hydrophobic insecticide malathion via alkaline hydrolysis (i.e. the hydrolysis-based model) driven by increased water pH resulting from photosynthesis. However, it is still unknown how generalizable these mitigation mechanisms are across the wide variety of insecticides applied today, and whether any general rules can be ascertained about which types of chemicals may be mitigated by each mechanism. We quantified the degree to which the submerged plant Elodea canadensis mitigated acute (48-h) toxicity to Daphnia magna using nine commonly applied insecticides spanning three chemical classes (carbamates: aldicarb, carbaryl, carbofuran; organophosphates: malathion, diazinon, chlorpyrifos; pyrethroids: permethrin, bifenthrin, lambda-cyhalothrin). We found that insecticides possessing either high octanol-water partition coefficients (log K ow ) values (i.e. pyrethroids) or high susceptibility to alkaline hydrolysis (i.e. carbamates and malathion) were all mitigated to some degree by E. canadensis, while the plant had no effect on insecticides possessing intermediate log K ow values and low susceptibility to hydrolysis (i.e. chlorpyrifos and diazinon). Our results provide the first general insights into which types of insecticides are likely to be mitigated by different mechanisms based on known chemical properties. We suggest that current models and mitigation strategies would be improved by the consideration of both mitigation models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Hydrologic alteration affects aquatic plant assemblages in an arid-land river

    Science.gov (United States)

    Vinson, Mark; Hestmark, Bennett; Barkworth, Mary E.

    2014-01-01

    We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale,Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

  12. Laboratory tests for the phytoextraction of heavy metals from polluted harbor sediments using aquatic plants.

    Science.gov (United States)

    Mânzatu, Carmen; Nagy, Boldizsár; Ceccarini, Alessio; Iannelli, Renato; Giannarelli, Stefania; Majdik, Cornelia

    2015-12-30

    The aim of this study was to investigate the concentrations and pollution levels of heavy metals, organochlorine pesticides, and polycyclic aromatic hydrocarbons in marine sediments from the Leghorn Harbor (Italy) on the Mediterranean Sea. The phytoextraction capacity of three aquatic plants Salvinia natans, Vallisneria spiralis, and Cabomba aquatica was also tested in the removal of lead and copper, present in high concentration in these sediments. The average detectable concentrations of metals accumulated by the plants in the studied area were as follows: >3.328 ± 0.032 mg/kg dry weight (DW) of Pb and 2.641 ± 0.014 mg/kg DW of Cu for S. natans, >3.107 ± 0.034 g/kg DW for V. spiralis, and >2.400 ± 0.029 mg/kg DW for C. aquatica. The occurrence of pesticides was also analyzed in the sediment sample by gas chromatography coupled with mass spectrometry (GC/MS). Due to its metal and organic compound accumulation patterns, S. natans is a potential candidate in phytoextraction strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Phenotypic responses to water flow and wave exposure in aquatic plants

    Directory of Open Access Journals (Sweden)

    Agnieszka Gałka

    2011-01-01

    Full Text Available Plastic responses of 10 aquatic plant species from 5 rivers and 5 lakes in NW Poland were examined. Chara fragilis, C. delicatula, Potamogeton pectinatus, P. perfoliatus, P. natans, Spirodela polyrhiza, Hydrocharis morsus-ranae, Salvinia natans, Nymphoides peltata and Juncus bulbosus were the subject of research. In the running water of rivers, rhizophytes were generally bigger and they allocated from 0.6% to 58.6% more biomass for anchoring in the substrate than in stagnant water (ox bow lakes. In both flow variants rhizophytes allocated a similar biomass fraction for generative reproduction. On the other hand, under the influence of water flow pleustophytes reduced the mass of an individual (Spirodela by 25%, Hydrocharis 67%, Salvinia 77% and emergent structures (p<0.001, and the number of sporangia (p<0.001. In both flow variants the input of biomass to generative reproduction was the same (Salvinia, or it was greater in running water (Hydrocharis; an increase from 4.9±1.3% to 15.1±3.6%. Under the conditions of strong wave action, in comparison with the lack of this environmental factor, Chara delicatula was several times shorter (p<0.001. However, it was also stouter, and as a result it had similar mass. In the areas of wave action the plant allocated 88.8% of its mass for anchoring in the substrate, whereas when there were no waves, only 22.7%.

  14. Toxicities of oils, dispersants and dispersed oils to algae and aquatic plants: review and database value to resource sustainability.

    Science.gov (United States)

    Lewis, Michael; Pryor, Rachel

    2013-09-01

    Phytotoxicity results are reviewed for oils, dispersants and dispersed oils. The phytotoxicity database consists largely of results from a patchwork of reactive research conducted after oil spills to marine waters. Toxicity information is available for at least 41 crude oils and 56 dispersants. As many as 107 response parameters have been monitored for 85 species of unicellular and multicellular algae, 28 wetland plants, 13 mangroves and 9 seagrasses. Effect concentrations have varied by as much as six orders of magnitude due to experimental diversity. This diversity restricts phytotoxicity predictions and identification of sensitive species, life stages and response parameters. As a result, evidence-based risk assessments for most aquatic plants and petrochemicals and dispersants are not supported by the current toxicity database. A proactive and experimentally-consistent approach is recommended to provide threshold toxic effect concentrations for sensitive life stages of aquatic plants inhabiting diverse ecosystems. Published by Elsevier Ltd.

  15. Biogas production from Eichhornia crassipes aquatic plant; Producao de biogas a partir da planta aquatica Eichhornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Silva, Jose Goncalves da; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil)]. E-mail: rbmelo@light.com.br

    2004-07-01

    Virtually all plants and waste plants and animals may in some way be used as an energy source. The anaerobic digestion of these materials is an option, resulting in the biogas. Besides the gas obtained in the process, is produced, inside the biodigester, an excellent fertilizer. The aquatic plant Eichhornia crassipes is found in large quantities in various water bodies, such as reservoirs, lakes and ponds, becoming mostly often a big problem and it is necessary its systematic removal of water. The bench biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced, and a reservoir to monitor the production of biogas. The reactor is located within a receptacle containing water that can be heated by an electrical resistance, with the purpose of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor made in a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity, show a percentage of 50% of methane in the biogas. The process of biodigestion of aquatic plant Eichhornia crassipes shows potential to obtain biogas, with considerable levels of methane in order to make its exploitation. Also, were analyzed the biomass in the biodigester for determination of humid, total organic matter, mineral and organic carbon residue.

  16. Toxic metals in aquatic plants surviving in surface water polluted by copper mining industry.

    Science.gov (United States)

    Samecka-Cymerman, A; Kempers, A J

    2004-09-01

    Concentrations of the metals Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn, as well as the macronutrients N, P, K, Ca, Mg, and S were measured in water, sediments, and the aquatic macrophytes Potamogeton pectinatus and Myriophyllum spicatum, growing in surface water receiving sewages and solid wastes from a copper smelter and a copper ore processing factory located in the Legnica-Glogow copper district in Southwest Poland. The deposition of mineral wastes in this area belong to the largest repository in Europe. The plants were able to survive at heavily contaminated sites. The concentrations of Cd (up to 0.6-1.7 microg/L in water and up to 10.1-12.9 mg/kg in sediments), Cu (up to 29-48 microg/L in water and up to 4.6-5.6g/kg in sediments), Pb (up to 1.5-2.2 g/kg in sediments), and Zn (up to 167-200 microg/L in water and up to 1.4-1.8 g/kg in sediments) seriously exceeded background values. P. pectinatus was able to survive tissue concentrations (in mg/kg) of up to 920 Cu, 6240 Mn, 98 Co, and 59 Ni, while M. spicatum survived tissue concentrations up to 1040 Cu, 6660 Mn, and 57 Co for. Enrichment ratios of elements in plant tissue and in water were much higher than those between plant tissue and sediments. Copyright 2003 Elsevier Inc.

  17. Is the tier-1 effect assessment for herbicides protective for aquatic algae and vascular plant communities?

    Science.gov (United States)

    van Wijngaarden, René P A; Arts, Gertie H P

    2018-01-01

    In the aquatic tier-1 effect assessment for plant protection products with an herbicidal mode of action in Europe, it is usually algae and/or vascular plants that determine the environmental risks. This tier includes tests with at least 2 algae and 1 macrophyte (Lemna). Although such tests are considered to be of a chronic nature (based on the duration of the test in relation to the life cycle of the organism), the measurement endpoints derived from the laboratory tests with plants (including algae) and used in the first-tier effect assessment for herbicides are acute effect concentrations affecting 50% of the test organisms (EC50 values) and not no-observed-effect concentrations (NOECs) or effect concentrations affecting 10% of the test organisms (EC10) values. Other European legislative frameworks (e.g., the Water Framework Directive) use EC10 values. The present study contributes to a validation of the tiered herbicide risk assessment approach by comparing the standard first-tier effect assessment with results of microcosm and mesocosm studies. We evaluated EC50 and EC10 values for standard test algae and macrophytes based on either the growth rate endpoint (Er C50) or the lowest available endpoint for growth rate or biomass/yield (Er /Ey C50). These values were compared with the regulatory acceptable concentrations for the threshold option as derived from microcosm and mesocosm studies. For these studies, protection is maintained if growth rate is taken as the regulatory endpoint instead of the lowest value of either growth rate or biomass/yield in conjunction with the standard assessment factor of 10. Based on a limited data set of 14 herbicides, we did not identify a need to change the current practice. Environ Toxicol Chem 2018;37:175-183. © 2017 SETAC. © 2017 SETAC.

  18. Metal(loid) accumulation in aquatic plants of a mining area: Potential for water quality biomonitoring and biogeochemical prospecting.

    Science.gov (United States)

    Favas, Paulo J C; Pratas, João; Rodrigues, Nelson; D'Souza, Rohan; Varun, Mayank; Paul, Manoj S

    2018-03-01

    Aquatic bryophytes can accumulate extremely high levels of chemical elements because of their unique morphology and physiology which is markedly different from vascular plants. Four aquatic mosses-Fontinalis squamosa, Brachythecium rivulare, Platyhypnidium riparioides, Thamnobryum alopecurum-and a freshwater red alga Lemanea fluviatilis along with water samples from the streams of Góis mine region in Central Portugal were analyzed for 46 elements. Despite being below detection levels in the water samples, the elements Zr, V, Cr, Mo, Ru, Os, Rh, Ir, Pt, Ag, Ge and Bi were obtained in the plant samples. The moss T. alopecurum had the highest mean concentrations of 19 elements followed by B. rivulare (15 elements). Maximum accumulation of Rb, Ta and Au, however, was seen in the alga L. fluviatilis. Bioconcentration factors > 10 6 were obtained for a few metals. The investigation confirms that aquatic bryophytes can be suitable for water quality biomonitoring and biogeochemical prospecting in fresh water bodies owing to their high accumulative capacity of multi-elements from their aquatic ambient. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments

    Science.gov (United States)

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-01

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants.

  20. Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis.

    Science.gov (United States)

    Velthuis, Mandy; van Deelen, Emma; van Donk, Ellen; Zhang, Peiyu; Bakker, Elisabeth S

    2017-01-01

    Human activity is currently changing our environment rapidly, with predicted temperature increases of 1-5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus). In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition consistently leads to

  1. Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Mandy Velthuis

    2017-05-01

    Full Text Available Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus. In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition

  2. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, pplants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, pplants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Aquatic vascular plants as handicraft: a case study in southern Brazil

    Directory of Open Access Journals (Sweden)

    Mabel R. Báez-Lizarazo

    2017-11-01

    Full Text Available ABSTRACT This study aimed to evaluate knowledge about and the usage and importance of aquatic vascular plants (AVPs in the production of handicrafts by communities on the north coast of the state of Rio Grande do Sul in southern Brazil. The snowball technique was employed to locate people who use and have knowledge regarding the use of AVPs for handicrafts. Data were collected through semi-structured interviews and guided tours with 35 interviewees who were involved in artisanal activity at the time of the study. The data were analyzed using the importance value (IV index and the consensus value for the forms of use (CMU. The Spearman correlation test (rs was employed to determine the correlations of each social variable with the knowledge variables, and Mann-Whitney U tests to verify whether men and women exhibited differences in knowledge. The interviewees cited 16 AVPs that were employed in 17 types of handicrafts, among which the four main species were Schoenoplectus californicus, Typha domingensis, T. latifolia and Androtrichum giganteum. Interviewee age, residence time on site and time working with handicrafts were the main social parameters that described the level of knowledge and use of AVPs. These AVPs reflect cultural knowledge and complement family incomes.

  4. Mitigating arsenic contamination in rice plants with an aquatic fern, Marsilea minuta.

    Science.gov (United States)

    Hassi, Ummehani; Hossain, Md Tawhid; Huq, S M Imamul

    2017-10-10

    Dangers of arsenic contamination are well known in human civilization. The threat increases when arsenic is accumulated in food and livestock through irrigated crops or animal food. Hence, it is important to mitigate the effects of arsenic as much as possible. This paper discusses a process for reducing the level of arsenic in different parts of rice plants with an aquatic fern, Marsilea minuta L. A pot experiment was done to study the possibility of using Marsilea minuta as a phytoremediator of arsenic. Rice and Marsilea minuta were allowed to grow together in soils. As a control, Marsilea minuta was also cultured alone in the presence and absence of arsenic (applied at 1 mg/L as irrigation water). We did not find any significant change in the growth of rice due to the association of Marsilea minuta, though it showed a reduction of approximately 58.64% arsenic accumulation in the roots of rice grown with the association of fern compared to that grown without fern. We measured a bioaccumulation factor (BF) of > 5.34, indicating that Marsilea minuta could be a good phytoremediator of arsenic in rice fields.

  5. Performance of aquatic plant species for phytoremediation of arsenic-contaminated water

    Science.gov (United States)

    Jasrotia, Shivakshi; Kansal, Arun; Mehra, Aradhana

    2017-05-01

    This study investigates the effectiveness of aquatic macrophyte and microphyte for phytoremediation of water bodies contaminated with high arsenic concentration. Water hyacinth ( Eichhornia crassipes) and two algae ( Chlorodesmis sp. and Cladophora sp.) found near arsenic-enriched water bodies were used to determine their tolerance toward arsenic and their effectiveness to uptake arsenic thereby reducing organic pollution in arsenic-enriched wastewater of different concentrations. Parameters like pH, chemical oxygen demand (COD), and arsenic concentration were monitored. The pH of wastewater during the course of phytoremediation remained constant in the range of 7.3-8.4, whereas COD reduced by 50-65 % in a period of 15 days. Cladophora sp. was found to survive up to an arsenic concentration of 6 mg/L, whereas water hyacinth and Chlorodesmis sp. could survive up to arsenic concentrations of 2 and 4 mg/L, respectively. It was also found that during a retention period of 10 days under ambient temperature conditions, Cladophora sp. could bring down arsenic concentration from 6 to plant species provides a simple and cost-effective method for application in rural areas affected with arsenic problem. The treated water can be used for irrigation.

  6. Phytoremediation capacity of aquatic plants is associated with the degree of phytochelatin polymerization.

    Science.gov (United States)

    Török, Anamaria; Gulyás, Zsolt; Szalai, Gabriella; Kocsy, Gábor; Majdik, Cornelia

    2015-12-15

    Phytochelatins (PCs) play important role in phytoremediation as heavy metal binding peptides. In the present study, the association between heavy metal removal capacity and phytochelatin synthesis was compared through the examination of three aquatic plants: Elodea canadensis, Salvinia natans and Lemna minor. In case of a Cd treatment, or a Cd treatment combined with Cu and Zn, the highest removal capacity was observed in L. minor. At the same time, E. canadensis showed the lowest removal capacity except for Zn. The heavy metal-induced (Cu+Zn+Cd) oxidative stress generated the highest ascorbate level in L. minor. Cd in itself or combined with the other two metals induced a 10-15-fold increase in the amount of ɣ-glutamylcysteine in L. minor while no or smaller changes were observed in the other two species. Correspondingly, the total PC content was 6-8-fold greater in L. minor. In addition, PCs with higher degree of polymerization were only observed in L. minor (PC4, PC6 and PC7) while PC2 and PC3 occurred in E. canadensis and S. natans only. The correlation analysis indicated that the higher phytoremediation capacity of L. minor was associated with the synthesis of PCs and their higher degree of polymerization. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Modeling anaerobic digestion of aquatic plants by rumen cultures: cattail as an example.

    Science.gov (United States)

    Zhao, Bai-Hang; Yue, Zheng-Bo; Ni, Bing-Jie; Mu, Yang; Yu, Han-Qing; Harada, Hideki

    2009-04-01

    Despite of the significance of the anaerobic digestion of lignocellulosic materials, only a limited number of studies have been carried out to evaluate the lignocellulosic digestion kinetics, and information about the modeling of this process is limited. In this work, a mathematical model, based on the Anaerobic Digestion Model No.1 (ADM1), was developed to describe the anaerobic conversion of lignocellulose-rich aquatic plants, with cattail as an example, by rumen microbes. Cattail was fractionated into slowly hydrolysable fraction (SHF), readily hydrolysable fraction (RHF) and inert fraction in the model. The SHF was hydrolyzed by rumen microbes and resulted in the production of RHF. The SHF and RHF had different hydrolysis rates but both with surface-limiting kinetics. The rumen microbial population diversity, including the cattail-, butyrate-, acetate- and H(2)-degraders, was all incorporated in the model structure. Experiments were carried out to identify the parameters and to calibrate and validate this model. The simulation results match the experimental data, implying that the fractionation of cattail into two biodegradation parts, i.e., SHF and RHF, and modeling their hydrolysis rate with a surface-limiting kinetics were appropriate. The model was capable of simulating the anaerobic biodegradation of cattail by the rumen cultures.

  8. Impact of temperature and nutrients on carbon:nutrient tissue stoichiometry of submerged aquatic plants: an experiment and meta-analysis

    NARCIS (Netherlands)

    Velthuis, M.; van Deelen, Emma; van Donk, E.; Zhang, P.; Bakker, E.S.

    2017-01-01

    Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource

  9. Investigation on concentration of elements in wetland sediments and aquatic plants

    Directory of Open Access Journals (Sweden)

    H. Janadeleh

    2016-01-01

    Full Text Available The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. Results showed that the mean  concentrations of elements in Phragmities australis  in root and stem-leaf were as follows: Iron:4448 mg/kg, Nickel: 28 mg/kg, Lead:8 mg/kg, Vanadium:10 mg/kg  and Zinc 15.5 mg/kg in root and: Fe:645 mg/kg, Ni:15 mg/kg, Pb:4 mg/kg, V:4 mg/kg and Zinc 16 mg/kg respectively. Also, the mean concentrations of Fe, Ni, Pb, V and Zn in roots of Typha latifolia were 8696 mg/kg, 34 mg/kg, 5 mg/kg, 19 mg/kg and 27 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb, Zn in stem-leaves of Typha latifolia were as follows: 321 mg/kg, 3 mg/kg, 7 mg/kg, 2 mg/kg and 14 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb and zinc were as: 40991 mg/kg, 65 mg/kg, 60 mg/kg, 31 mg/kg, 60 mg/kg respectively in surface sediment of study area. Concentration pattern of elements in sediment were as: Fe>Ni>Zn>V>Pb. The highest concentration of elements in the plant was seen in the roots. Also, Typha latifolia can uptake more concentration of elements than Phragmities australis. Based on the enrichment factor, Ni in summer had the highest EF values among the elements studied and it has a moderate enrichment.

  10. Roles for root iron plaque in sequestration and uptake of heavy metals and metalloids in aquatic and wetland plants.

    Science.gov (United States)

    Tripathi, Rudra D; Tripathi, Preeti; Dwivedi, Sanjay; Kumar, Amit; Mishra, Aradhana; Chauhan, Puneet S; Norton, Gareth J; Nautiyal, Chandra S

    2014-10-01

    Toxic metal(loid) contamination of soil and sediment poses long term risk to soil and human health through plant-human or plant-animal-human food chain pathways. Iron plaque (IP) formation is frequent in aquatic and wetland plant species and is responsible for the sequestration of various metal(loids). The presence of IP may act as a buffer or barrier and may thus enhance or reduce the uptake of potentially phytotoxic metals and metalloids by plants. If IP acts as a barrier, then low IP producing macrophytes/aquatic plants may be better accumulators of toxic metals and may find use in constructed wetlands for remediation of pollutants, while high IP forming edible plant species could be safer for human consumption. Conversely, if IP acts as a buffer for mineral nutrients and toxic elements then those cultivars may be rich in nutrients, but may also cause toxicity. However, an ecotoxicological risk is also inevitable if IP rich macrophyte roots containing heavy metals are consumed by herbivores. In this review, we summarize the current understanding about the role of IP in metal and metalloid sequestration, uptake, and transport. Furthermore, we will address the role of root IP in Oryza sativa for arsenic (As) sequestration leading to lower grain As translocation, reducing the risk of human exposure.

  11. Biodigestion of the aquatics plants mixtures and biogas production; Biodigestao de misturas de plantas aquaticas e producao de biogas

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Abreu, Fernando Luiz Barbuda de; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil). Gerencia de Estudos e Gestao de Geracao]. E-mail: rbmelo@light.com.br

    2004-07-01

    Several systems of generating electricity using water storage reservoirs. One problem that occurs constantly in these reservoirs is the accumulation of aquatic plants, such as Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes and Salvinia that may cause serious problems for the system. Periodically, the biomass must be removed and disposed of appropriate form, so that does not cause contamination of soil, groundwater or allowing the proliferation of vectors. One possible destination is the use of biomass in a process of biodigestion, resulting in biogas. The bench of biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced and a reservoir for the monitoring the production of biogas. The reactor is located inside a container containing water that can be heated by an electrical resistance, with the aim of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor was obtained using a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity. These results show a percentage of 50% of methane in the biogas. Also, were analyzed the biomass in the biodigester for determination of humidity, total organic matter, waste mineral and organic carbon. The process of biodigestion of the mixture of aquatic plants: Eichhornia crassipes, Eichhornia azurea and Pistia stratiotes and Salvinia shows potential for obtaining biogas, with considerable levels of methane, in order to facilitate its recovery.

  12. New approach for the removal of metal ions from water: adsorption onto aquatic plants and microwave reaction for the fabrication of nanometals.

    Science.gov (United States)

    Chefetz, B; Sominski, L; Pinchas, M; Ginsburg, T; Elmachliy, S; Tel-Or, E; Gedanken, A

    2005-08-18

    We adsorb heavy metal ions such as Ag(+), Pb(2+), and Ru(3+) onto an aquatic plant and convert the adsorbed ions to the corresponding nanometallic particles by the polyol reaction carried out in a microwave oven.

  13. Cytokinin, auxin and physiological polarity in the aquatic carnivorous plants Aldrovanda vesiculosa and Utricularia australis.

    Science.gov (United States)

    Šimura, Jan; Spíchal, Lukáš; Adamec, Lubomír; Pěnčík, Aleš; Rolčík, Jakub; Novák, Ondřej; Strnad, Miroslav

    2016-05-01

    The typical rootless linear shoots of aquatic carnivorous plants exhibit clear, steep polarity associated with very rapid apical shoot growth. The aim of this study was to determine how auxin and cytokinin contents are related to polarity and shoot growth in such plants. The main auxin and cytokinin metabolites in separated shoot segments and turions of two carnivorous plants, Aldrovanda vesiculosa and Utricularia australis, were analysed using ultra-high-performance liquid chromatography coupled with triple quad mass spectrometry. In both species, only isoprenoid cytokinins were identified. Zeatin cytokinins predominated in the apical parts, with their concentrations decreasing basipetally, and the trans isomer predominated in A. vesiculosa whereas the cis form was more abundant in U australis. Isopentenyladenine-type cytokinins, in contrast, increased basipetally. Conjugated cytokinin metabolites, the O-glucosides, were present at high concentrations in A. vesiculosa but only in minute amounts in U. australis. N(9)-glucoside forms were detected only in U. australis, with isopentenyladenine-9-glucoside (iP9G) being most abundant. In addition to free indole-3-acetic acid (IAA), indole-3-acetamide (IAM), IAA-aspartate (IAAsp), IAA-glutamate (IAGlu) and IAA-glycine (IAGly) conjugates were identified. Both species show common trends in auxin and cytokinin levels, the apical localization of the cytokinin biosynthesis and basipetal change in the ratio of active cytokinins to auxin, in favour of auxin. However, our detailed study of cytokinin metabolic profiles also revealed that both species developed different regulatory mechanisms of active cytokinin content; on the level of their degradation, in U. australis, or in the biosynthesis itself, in the case of A. vesiculosa Results indicate that the rapid turnover of these signalling molecules along the shoots is essential for maintaining the dynamic balance between the rapid polar growth and development of the apical

  14. Density-dependent reproductive and vegetative allocation in the aquatic plant Pistia stratiotes (Araceae

    Directory of Open Access Journals (Sweden)

    Flávia Freitas Coelho

    2005-09-01

    Full Text Available Pistia stratiotes is an aquatic macrophyte that grows in temporary-ponds in the southern Pantanal, Brazil. It reproduces both sexually and asexually and is usually observed forming dense mats on the water surface, a condition favored by the plant’s vegetative reproduction coupled with an ability for rapid growth. In this study we examined the effect of densely crowded conditions on the production of reproductive and vegetative structures. In addition, we verified whether there is a trade-off between clonal growth and investment in sexual reproductive structures, and whether there is an allocation pattern with plant size. Individual plant biomass and the number of the rosettes producing sexual reproductive structures and vegetative growth structures both increased with density. Increase in plant size resulted in increased proportional allocation to sexual reproductive structures and vegetative growth structures. Allocation of biomass to reproduction did not occur at the expense of clonal growth. Thus, the density response appears as a increase of rosettes producing sexual reproductive structures and vegetative growth structures. Therefore, long leaves and stolons may be adaptive under densely crowded conditions where competition for light is intense. An important aspect in the study of trade-offs is the size-dependency of the allocation patterns .Usually, larger plants produce more biomass. Therefore, larger plants can allocate more biomass to both vegetative and sexual reproduction than smaller plants and thus show a positive correlation between both traits rather than the expected negative one. Rev. Biol. Trop. 53(3-4: 369-376. Epub 2005 Oct 3.Pistias strariotes es una macrófita acuática que crece en charcas estacionales en el Pantanal sureño de Brasil. Se reproduce tanto sexual como asexualmente y se obsrva generalmente que forma densas parches sobre la superficie del agua, una condicion que favorecida por la reproduccion vegetativa de la

  15. THE ABILITY OF LEAVES AND RHIZOMES OF AQUATIC PLANTS TO ACCUMULATE MACRO- AND MICRONUTRIENTS

    Directory of Open Access Journals (Sweden)

    Agnieszka Edyta Parzych

    2015-06-01

    Full Text Available The samples of macrophytes and bottom sediments originated from the littoral zone of the Słupia River were collected in summer 2013. The aim of this study was to compare the properties of the accumulation of leaves and rhizomes of Glyceria maxima, Phragmites australis, Typha latifolia and Phalaris arundinacea for macro- and micronutrients. The largest quantities of macroelements were found in the leaves of the examined species, and microelements dominated the rhizomes of most examined macrophytes except for Mn in P.australis and T.latifolia. The obtained results show that N and K dominated in the leaves of P.arundinacea, P and Mg in the leaves of P.australis, and Ca in the leaves of G.maxima. The largest quantities of N, P and K were cumulated in the rhizomes of P.arundinacea, while Mg and Ca in the rhizome of T.latifolia. The leaves of aquatic plants accumulated from 1354.9 mmolc·kg-1 (T.latifolia to 1844.0 mmolc·kg-1 (P.arundinacea, and rhizomes from 985.8 mmolc·kg-1 (G.maxima to 1335.2 mmolc·kg-1 (P.arundinacea of all the analyzed components. In these species of macrophytes lower accumulated value of the sum of macro- and microelements were found in the rhizomes. The share of nitrogen was 42.4–59.8% of this amount, phosphorus 4.3–8.6%, potassium 22.8–35.1%, calcium from 2,6% to 12.4%, magnesium 3.0–7.5%, and heavy metals were from 0.6% (G.maxima to 1.2% (T.latifolia in leaves and from 2.2% (T.latifolia to 8.7% (G.maxima in rhizomes.

  16. Biomonitoring of nutrient and toxic element concentrations in the Sarno River through aquatic plants.

    Science.gov (United States)

    Baldantoni, Daniela; Bellino, Alessandro; Lofrano, Giusy; Libralato, Giovanni; Pucci, Luca; Carotenuto, Maurizio

    2018-02-01

    The Sarno River is considered the most polluted river in Europe and one of the ten most polluted rivers in the world. So far, its quality has been usually evaluated by water and sediment analyses of either inorganic or organic pollutants. However, a biomonitoring approach would be of paramount importance in the evaluation of river quality, since it integrates pollutant temporal fluctuations, as in the case of discontinuous inputs from urban, industrial and agricultural activities. To this end, a passive biomonitoring study of the Sarno River was carried out, using two native aquatic plants accumulators of inorganic pollutants. The spring area was monitored analysing the roots of the semi-submerged Apium nodiflorum, whereas the whole river course was monitored analysing the shoots of the submerged Potamogeton pectinatus. The information on the four macronutrient (Ca, K, Mg, P), the six micronutrient (Cu, Fe, Mn, Na, Ni, Zn) and the four toxic element (Cd, Cr, Pb, V) concentrations were separately combined in the Nemerow Pollution Index. Results evidenced a severe pollution degree of the Sarno River, attributable to toxic elements > micronutrients > macronutrients. In particular, the spring area showed high K concentrations, as well as high concentrations of several micronutrients and toxic elements. A generalized Zn contamination and a progressive macronutrient (above all Ca and P), micronutrient (above all Ni, Cu and Fe) and toxic element (above all Cr and Pb) accumulation toward the mouth was related to pollution from agricultural and urban activities. Industrial sources, especially tanneries along the Solofrana tributary, accounted for high Mn concentrations, whereas the volcanic origin of the substrate accounted for a generalized V contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Genome size as a key to evolutionary complex aquatic plants: polyploidy and hybridization in Callitriche (Plantaginaceae.

    Directory of Open Access Journals (Sweden)

    Jan Prančl

    Full Text Available Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid-tetraploid complex C. cophocarpa-C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced

  18. Anti-tumour activities of fucoidan from the aquatic plant Utricularia aurea lour

    Directory of Open Access Journals (Sweden)

    Wilaiwan Chotigeat

    2005-12-01

    Full Text Available Fucoidan, a sulfated polysaccharide with several biological activities, is usually isolated from marine seaweeds or from echinoderms. Here, we report on the anti-tumour activity of fucoidan isolated from the aquatic plant Utricularia aurea Lour (Lentibulariaceae. A crude extract (CE prepared by incubating U.aurea with hot water at 95ºC for 12 hr was partially purified by Sephadex G-50, eluting with a 50mM sodium acetate buffer, at pH 5.0, containing 0.5M NaCl. Partially purified fucoidan (PPF had a 3- fold increase in fucose content when compared with the CE and a molecular weigÄt of 11.6 kDa as determined by Sephadex G-200. Chemical analysis showed that CE consisted of 62.5% glucuronic acid, 5.0% fucose, 1.7% sulfate and 12.0% proteins while PPF consisted of 65.0% glucuronic acid, 15.3% fucose, 2.1 % sulfate and 8.3% proteins.The anti-tumour activity of the CE and PPF was determined by the MTT test. The CE at 125 μg/mL fucoidan and PPF at 250 μg/mL inhibited the growth of KB cells (a nasopharynx tumour cell line, but did not inhibit that of normal fibroblast cells. The inhibition was postulated to occur via apoptosis as significantlymore apoptotic cells were found after treatment than in the untreated KB cells (P<0.05 by the TUNNEL (TdT-mediated dUTP Nick-End Labelling assay.

  19. Effectiveness of emergent and submergent aquatic plants in mitigating a nitrogen-permethrin mixture

    Science.gov (United States)

    The current study assessed the effectiveness of varying combinations of two common aquatic vascular macrophytes, parrot feather (Myriophyllum aquaticum) and cattail (Typha latifolia) for mitigating contamination from a mixture of nitrogen (ammonium nitrate) and permethrin. Hydraulically connected we...

  20. Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr.

    1979-01-01

    A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to better evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program.

  1. Above- and below-ground vertebrate herbivory may each favour a different subordinate species in an aquatic plant community.

    Science.gov (United States)

    Hidding, Bert; Nolet, Bart A; de Boer, Thijs; de Vries, Peter P; Klaassen, Marcel

    2010-01-01

    At least two distinct trade-offs are thought to facilitate higher diversity in productive plant communities under herbivory. Higher investment in defence and enhanced colonization potential may both correlate with decreased competitive ability in plants. Herbivory may thus promote coexistence of plant species exhibiting divergent life history strategies. How different seasonally tied herbivore assemblages simultaneously affect plant community composition and diversity is, however, largely unknown. Two contrasting types of herbivory can be distinguished in the aquatic vegetation of the shallow lake Lauwersmeer. In summer, predominantly above-ground tissues are eaten, whereas in winter, waterfowl forage on below-ground plant propagules. In a 4-year exclosure study we experimentally separated above-ground herbivory by waterfowl and large fish in summer from below-ground herbivory by Bewick's swans in winter. We measured the individual and combined effects of both herbivory periods on the composition of the three-species aquatic plant community. Herbivory effect sizes varied considerably from year to year. In 2 years herbivore exclusion in summer reinforced dominance of Potamogeton pectinatus with a concomitant decrease in Potamogeton pusillus, whereas no strong, unequivocal effect was observed in the other 2 years. Winter exclusion, on the other hand, had a negative effect on Zannichellia palustris, but the effect size differed considerably between years. We suggest that the colonization ability of Z. palustris may have enabled this species to be more abundant after reduction of P. pectinatus tuber densities by swans. Evenness decreased due to herbivore exclusion in summer. We conclude that seasonally tied above- and below-ground herbivory may each stimulate different components of a macrophyte community as they each favoured a different subordinate plant species.

  2. Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management.

    Science.gov (United States)

    Wood, Kevin A; Stillman, Richard A; Daunt, Francis; O'Hare, Matthew T

    2014-01-01

    Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems.

  3. Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management.

    Directory of Open Access Journals (Sweden)

    Kevin A Wood

    Full Text Available Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i food quantity, (ii food quality, and (iii the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems.

  4. Phytotoxicity and accumulation of zinc oxide nanoparticles on the aquatic plants Hydrilla verticillata and Phragmites Australis: leaf-type-dependent responses.

    Science.gov (United States)

    Song, Uhram; Lee, Sunryung

    2016-05-01

    The phytotoxicity and accumulation of zinc oxide nanoparticles (ZnO NPs) on aquatic plant Hydrilla verticillata and Phragmites australis were investigated using mesocosms. The percentage of dissolved Zn in the ZnO NP treatment solutions was measured along with plant shoot growth, antioxidant enzyme activity, chlorophyll content, and Zn content. The dissolution rate of ZnO NPs in Hoagland solution was inversely related to the concentration. The submerged aquatic plant H. verticillata, growth was reduced during the early stages of the experiment when exposed to the highest ZnO NP concentration (1000 mg/L), whereas the emerged aquatic plant P. australis began to show significantly reduced growth after a few weeks. The measurements of chlorophyll content, antioxidant enzyme activity, and Zn accumulation showed that P. australis was adversely affected by NPs and absorbed more Zn than H. verticillata. The results indicated that physiological differences among aquatic plants, such as whether they use leaves or roots for nutrient and water uptake, led to differences in nanoparticle toxicity. Overall, High ZnO NP concentrations caused significant phytotoxicity on aquatic plants, and low concentrations caused unpredictable phytotoxicity. Therefore, the use and disposal of zinc oxide nanoparticles should be carefully monitored.

  5. Captive bubble and sessile drop surface characterization of a submerged aquatic plant, Hydrilla verticillata

    Science.gov (United States)

    The surface energy parameters of the invasive aquatic weed, Hydrilla verticillata, were determined using contact angle measurements using two different methods. The abaxial and adaxial surfaces of the leaves and stem were characterized for the weed while submerged in water using captive air and octa...

  6. Proceedings of Annual Meeting (26th) Aquatic Plant Control Research Program, Held in Dallas, Texas on 18-22 November, 1991

    Science.gov (United States)

    1992-06-01

    com- uniconazole . and paclobutrazol were applied pound be usceptible to nonphotodegradative at I ppm a.i. The water was sanmpled over a processes...26 Effects of Aquatic Plants on Water Quality in Pond Ecosystems by David Honnell, John D. Madsen, and R. Michael Smart ................... 30...Flowing Water by David Sisneros .......... .................................. 97 Controlling Submersed Plants with Herbicides in Flowing Water Systems by

  7. Image spectroscopy and stable isotopes elucidate functional dissimilarity between native and nonnative plant species in the aquatic environment.

    Science.gov (United States)

    Santos, Maria J; Hestir, Erin L; Khanna, Shruti; Ustin, Susan L

    2012-02-01

    • Nonnative species may change ecosystem functionality at the expense of native species. Here, we examine the similarity of functional traits of native and nonnative submersed aquatic plants (SAP) in an aquatic ecosystem. • We used field and airborne imaging spectroscopy and isotope ratios of SAP species in the Sacramento-San Joaquin Delta, California (USA) to assess species identification, chlorophyll (Chl) concentration, and differences in photosynthetic efficiency. • Spectral separability between species occurs primarily in the visible and near-infrared spectral regions, which is associated with morphological and physiological differences. Nonnatives had significantly higher Chl, carotene, and anthocyanin concentrations than natives and had significantly higher photochemical reflectance index (PRI) and δ(13) C values. • Results show nonnative SAPs are functionally dissimilar to native SAPs, having wider leaf blades and greater leaf area, dense and evenly distributed vertical canopies, and higher pigment concentrations. Results suggest that nonnatives also use a facultative C(4) -like photosynthetic pathway, allowing efficient photosynthesis in high-light and low-light environments. Differences in plant functionality indicate that nonnative SAPs have a competitive advantage over native SAPs as a result of growth form and greater light-use efficiency that promotes growth under different light conditions, traits affecting system-wide species distributions and community composition. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  8. Utilization of two invasive free-floating aquatic plants (Pistia stratiotes and Eichhornia crassipes) as sorbents for oil removal.

    Science.gov (United States)

    Yang, Xunan; Chen, Shanshan; Zhang, Renduo

    2014-01-01

    Free-floating aquatic plants Pistia stratiotes and Eichhornia crassipes are well-known invasive species in the tropics and subtropics. The aim of this study was to utilize the plants as cost-effective and environmentally friendly oil sorbents. Multilevel wrinkle structure of P. stratiotes leaf (PL), rough surface of E. crassipes leaf (EL), and box structure of E. crassipes stalk (ES) were observed using the scanning electron microscope. The natural hydrophobic structures and capillary rise tests supported the idea to use P. stratiotes and E. crassipes as oil sorbents. Experiments indicated that the oil sorption by the plants was a fast process. The maximum sorption capacities for different oils reached 5.1-7.6, 3.1-4.8, and 10.6-11.7 g of oil per gram of sorbent for PL, EL, and ES, respectively. In the range of 5-35 °C, the sorption capacities of the plants were not significantly different. These results suggest that the plants can be used as efficient oil sorbents.

  9. Roles of emeriti professors

    OpenAIRE

    Thody, Angela

    2008-01-01

    Emeritus Professor Angela Thody commenced a study of emeriti professors in 2006 when she herself had become an emeritus in 2003 and was seeking to establish an Association for emeriti at her university at Lincoln. By 2008, the literature review was finished and a pilot study of emeriti professors at Leicester University was underway. This presentation was one of several to the University of Lincoln's College of Professors to encourage their support for the formation of the association and to ...

  10. [Correlation between aquatic plant diversity and water environment in the typical sites of Hangzhou section of the Beijing-Hangzhou Grand Canal].

    Science.gov (United States)

    Lu, Yin; Xu, Xiao-Lu; Zhang, De-Yong; Wang, Li; Zhu, Xu-Ni; Feng, Feng; Zhou, Qiao-Jun; Xie, Peng

    2014-05-01

    Community characteristics of aquatic plant are important indicators for water quality. In order to understand the distribution characteristics of aquatic plants in aquatic ecosystem of the Beijing-Hangzhou Grand Canal ( Hangzhou section) , and to analyze the relationship between water quality and plant community, an investigation of the aquatic plants in five typical sites was made in this study. Species composition, biological diversity, quantity distribution and dominant species of aquatic plants in five sites were studied for ecological changes. Physicochemical factors such as temperature, pH value, transparency, dissolved oxygen and main elements of living were also analyzed. Based on the results, the distribution of phytoplankton diversity and environment factor correlations by multivariate statistical analysis were discussed. The trophic levels of these sites were assessed by using related biological standards. Results indicated that the diversity of aquatic plant mainly depends on the diversity of phytoplankton in the typical sites of the Beijing-Hangzhou Grand Canal. We observed and identified 35 genus algae, including advantage community of Hyalodiscus Ehrenberg and Melosira Agardh, which belonged to Bacillariophyta. According to the impact on the phytoplankton diversity and distribution, factors such as dissolved oxygen, transparency, water temperature, etc. had an obvious influence on the distribution of phytoplankton in the existing 6 environmental factors, while the influence of pH value was the highest. In terms of water quality eutrophication, site Tangxi Bridge and Maiyu Bridge showed a relatively lighter pollution, while site Yiqiao Bridge, Gujia Bridge and Gongchen Bridge showed a higher pollution, and the pollution of site Yiqiao Bridge was the most serious.

  11. PROFESSOR ENSERMU KELBESSA

    African Journals Online (AJOL)

    2016-08-14

    Aug 14, 2016 ... University, Sweden in 1990. Although still very young, Professor Ensermu Kelbessa joined the Addis Ababa. University's Biology Department as a graduate assistant in 1979. He then went on to serve the university in various positions including: Lecturer, Assistant Professor, Associate. Professor and, finally ...

  12. Arsenic, zinc, and aluminium removal from gold mine wastewater effluents and accumulation by submerged aquatic plants (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata).

    Science.gov (United States)

    Abu Bakar, Ahmad Farid; Yusoff, Ismail; Fatt, Ng Tham; Othman, Faridah; Ashraf, Muhammad Aqeel

    2013-01-01

    The potential of three submerged aquatic plant species (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata) to be used for As, Al, and Zn phytoremediation was tested. The plants were exposed for 14 days under hydroponic conditions to mine waste water effluents in order to assess the suitability of the aquatic plants to remediate elevated multi-metals concentrations in mine waste water. The results show that the E. densa and H. verticillata are able to accumulate high amount of arsenic (95.2%) and zinc (93.7%) and resulted in a decrease of arsenic and zinc in the ambient water. On the other hand, C. piauhyensis shows remarkable aluminium accumulation in plant biomass (83.8%) compared to the other tested plants. The ability of these plants to accumulate the studied metals and survive throughout the experiment demonstrates the potential of these plants to remediate metal enriched water especially for mine drainage effluent. Among the three tested aquatic plants, H. verticillata was found to be the most applicable (84.5%) and suitable plant species to phytoremediate elevated metals and metalloid in mine related waste water.

  13. Arsenic, Zinc, and Aluminium Removal from Gold Mine Wastewater Effluents and Accumulation by Submerged Aquatic Plants (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata

    Directory of Open Access Journals (Sweden)

    Ahmad Farid Abu Bakar

    2013-01-01

    Full Text Available The potential of three submerged aquatic plant species (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata to be used for As, Al, and Zn phytoremediation was tested. The plants were exposed for 14 days under hydroponic conditions to mine waste water effluents in order to assess the suitability of the aquatic plants to remediate elevated multi-metals concentrations in mine waste water. The results show that the E. densa and H. verticillata are able to accumulate high amount of arsenic (95.2% and zinc (93.7% and resulted in a decrease of arsenic and zinc in the ambient water. On the other hand, C. piauhyensis shows remarkable aluminium accumulation in plant biomass (83.8% compared to the other tested plants. The ability of these plants to accumulate the studied metals and survive throughout the experiment demonstrates the potential of these plants to remediate metal enriched water especially for mine drainage effluent. Among the three tested aquatic plants, H. verticillata was found to be the most applicable (84.5% and suitable plant species to phytoremediate elevated metals and metalloid in mine related waste water.

  14. Remote sensing bio-control damage on aquatic invasive alien plant ...

    African Journals Online (AJOL)

    Naeem

    Feeding scars also serve as sites for plant pathogen infection making the plant susceptible to disease infection (Julien, 2001). It is a combination of the morphological and physiological stresses mentioned above that alters the spectral reflectance of infested plants at the leaf surface (Everitt et al., 2005; Robles et al., 2010).

  15. Microbial community analysis in the roots of aquatic plants and isolation of novel microbes including an organism of the candidate phylum OP10.

    Science.gov (United States)

    Tanaka, Yasuhiro; Tamaki, Hideyuki; Matsuzawa, Hiroaki; Nigaya, Masahiro; Mori, Kazuhiro; Kamagata, Yoichi

    2012-01-01

    A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40-4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5-3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms.

  16. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae.

    Science.gov (United States)

    Chen, Ling-Yun; Chen, Jin-Ming; Gituru, Robert Wahiti; Wang, Qing-Feng

    2012-03-10

    Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite) and divergence time estimates (BEAST) resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma). Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges) probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Our study has shed light on the previously controversial

  17. Mechanical Harvesting of Aquatic Plants. Report 2. Evaluation of Selected Handling Functions of Mechanical Control.

    Science.gov (United States)

    1980-06-01

    Test site locations 12 0 a ’-4 0 C𔃾 13 rI a. Topped out hydrilla north of Bonnet Lake (August 1977) b. Topped out hydrilla north of Highway 48 bridge...Towing test in submersed aquatics 25 cut in Bonnet Lake (see Figure 9). The pushing rake mounted on a flat-bottom boat was used in the tests (Figure 11...Laboratory Technical Publications, a facsimile catalog card in Library of Congress MARC format is reproduced below. Smith, Perry A Mechanical harvesting of

  18. The toxic effects of l-Cysteine-capped cadmium sulfide nanoparticles on the aquatic plant Spirodela polyrrhiza

    Science.gov (United States)

    Khataee, Alireza; Movafeghi, Ali; Nazari, Fatemeh; Vafaei, Fatemeh; Dadpour, Mohammad Reza; Hanifehpour, Younes; Joo, Sang Woo

    2014-12-01

    Plants play an important role in the fate of nanoparticles in the environment through their uptake, bioaccumulation, and transfer to trophic chains. However, the impacts of nanoparticles on plants as essential components of all ecosystems are not well documented. In the present study, the toxic effects of l-Cysteine-capped CdS nanoparticles on Spirodela polyrrhiza as an aquatic higher plant species were studied. l-Cysteine-capped CdS nanoparticles were synthesized using hydrothermal method and their characteristics were determined by XRD, SEM, HR-TEM, and FT-IR techniques. The diameter of majority of synthesized nanoparticles was about 15-20 nm. Subsequently, the uptake of l-Cysteine-capped CdS nanoparticles by the plant species was confirmed using epifluorescence microscopy. The activity of peroxidase and superoxide dismutase as antioxidant enzymes was assayed and the relative frond number was calculated in the presence of different concentrations of l-Cysteine-capped CdS nanoparticles. The obtained results revealed the toxic effects of the synthesized nanoparticles on S. polyrrhiza, leading to growth reduction and significant changes in antioxidant enzymes' activity.

  19. Fate of Flumioxazin in Aquatic Plants: Two Algae (Pseudokirchneriella subcapitata, Synechococcus sp.), Duckweed (Lemna sp.), and Water Milfoil (Myriophyllum elatinoides).

    Science.gov (United States)

    Ando, Daisuke; Fujisawa, Takuo; Katagi, Toshiyuki

    2017-10-11

    Flumioxazin separately 14 C-labeled at 1,2-positions of the tetrahydrophthalimide moiety or uniformly labeled at the phenyl ring was exposed to two algae and duckweed via the water layer and water milfoil via the water layer or bottom sediment for 14 days to investigate uptake and metabolic profiles in these aquatic plants. While 14 C-flumioxazin received immediate hydrolysis through maleimide ring opening and amide bond cleavage with its hydrolytic half-life of plant uptake was ≤4.7% of the applied radioactivity (%AR) with water exposure for all plants and 0.9%AR with sediment exposure for water milfoil. No 14 C-translocation between shoot/leaves and roots occurred in water milfoil. The components of 14 C residues in plants were common among the species, which were the above hydrolysates and their transformation products, that is, dicarboxylic acid derivative metabolized via hydroxylation at the double bond of the cyclohexene ring followed by sugar conjugation with its counterpart amine derivative via acid conjugations.

  20. The toxic effects of l-Cysteine-capped cadmium sulfide nanoparticles on the aquatic plant Spirodela polyrrhiza

    Energy Technology Data Exchange (ETDEWEB)

    Khataee, Alireza, E-mail: ar_khataee@yahoo.com [University of Tabriz, Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry (Iran, Islamic Republic of); Movafeghi, Ali [University of Tabriz, Department of Plant Biology, Faculty of Natural Sciences (Iran, Islamic Republic of); Nazari, Fatemeh [University of Tabriz, Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry (Iran, Islamic Republic of); Vafaei, Fatemeh [University of Tabriz, Department of Plant Biology, Faculty of Natural Sciences (Iran, Islamic Republic of); Dadpour, Mohammad Reza [University of Tabriz, Department of Horticultural Science, Faculty of Agriculture (Iran, Islamic Republic of); Hanifehpour, Younes; Joo, Sang Woo, E-mail: swjoo@yu.ac.kr [Yeungnam University, School of Mechanical Engineering (Korea, Republic of)

    2014-12-15

    Plants play an important role in the fate of nanoparticles in the environment through their uptake, bioaccumulation, and transfer to trophic chains. However, the impacts of nanoparticles on plants as essential components of all ecosystems are not well documented. In the present study, the toxic effects of l-Cysteine-capped CdS nanoparticles on Spirodela polyrrhiza as an aquatic higher plant species were studied. l-Cysteine-capped CdS nanoparticles were synthesized using hydrothermal method and their characteristics were determined by XRD, SEM, HR-TEM, and FT-IR techniques. The diameter of majority of synthesized nanoparticles was about 15–20 nm. Subsequently, the uptake of l-Cysteine-capped CdS nanoparticles by the plant species was confirmed using epifluorescence microscopy. The activity of peroxidase and superoxide dismutase as antioxidant enzymes was assayed and the relative frond number was calculated in the presence of different concentrations of l-Cysteine-capped CdS nanoparticles. The obtained results revealed the toxic effects of the synthesized nanoparticles on S. polyrrhiza, leading to growth reduction and significant changes in antioxidant enzymes’ activity.Graphical Abstract.

  1. A weight-of-evidence approach for deriving a level of concern for atrazine that is protective of aquatic plant communities.

    Science.gov (United States)

    Moore, Dwayne Rj; Greer, Colleen D; Manning, Gillian; Wooding, Katie; Beckett, Kerrie J; Brain, Richard A; Marshall, Gary

    2017-07-01

    Atrazine is a selective triazine herbicide widely used in the United States primarily for control of broadleaf weeds in corn and sorghum. In 2003, the US Environmental Protection Agency (USEPA) concluded that atrazine poses potential risks to sensitive aquatic species. Consequently, a surface water monitoring program was developed to assess whether measured levels of atrazine could impact aquatic plants in vulnerable watersheds. To facilitate evaluation of the monitoring data, the Agency needed to establish a level of concern (LOC) below which atrazine would not cause unacceptable adverse effects to aquatic plant communities. Several attempts at developing a community-level LOC have followed from USEPA but none have been formally accepted or endorsed by independent Scientific Advisory Panels. As part of registration review, the USEPA needs to revisit development of a community-level LOC for atrazine that will be protective of aquatic plant communities. This article reviews 4 methods that can or have been used for this purpose. Collectively, the methods take advantage of the large number of single species and mesocosm studies that have been conducted for aquatic plants exposed to atrazine. The Plant Assemblage Toxicity Index (PATI) and the Comprehensive Aquatic Systems Model for atrazine (CASM ATZ2 ) incorporate single-species toxicity data but are calibrated with micro- and mesocosm study results to calculate community-level LOCs. The Brock et al. scoring system relies exclusively on mesocosm studies. Single-species toxicity data were used in a modified version of the USEPA's Water Quality Criteria (WQC) method. The 60-day LOCs calculated using the 4 methods ranged from 19.6 to 26 µg/L. A weight-of-evidence assessment indicated that the CASM ATZ2 method was the most environmentally relevant and statistically reliable method. Using all 4 methods with weights based on method reliability, the weighted 60-day LOC was 23.6 µg/L. Integr Environ Assess Manag 2017

  2. Uptake of 210Po by aquatic plants of a fresh water ecosystem around the uranium mill tailings management facility of Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K; Puranik, V D

    2013-10-01

    The present study was designed to investigate the uptake of Polonium-210 ((210)Po) by aquatic plants growing in a fresh water ecosystem around the tailings management facility of the uranium industry of Jaduguda, India. Evaluation of the activity concentration of (210)Po in aquatic plants, the concentration ratio of (210)Po from substrate to plants and the relationship of (210)Po with other stable elements were major objectives of the investigation. Based on the habitat, three types of plant were collected and analyzed for (210)Po activity estimation. Along with aquatic plants, effluent, surface water and bottom sediment were also collected and analyzed for (210)Po activity content. From the acid solution (210)Po was electrodeposited on brightly polished silver discs and counted for alpha activity in an alpha counter. The highest (210)Po activity concentration (4884 Bq kg(-1) fresh weight) was found in filamentous algae from residual water of the tailings pond. For sediment-rooted plants, a significant positive correlation (r = 0.91, p plant and sediment activity concentration of (210)Po. For all of the three different groups of plants studied, highly significant correlations were observed between activity concentration of (210)Po and Cu with the significance level variation between 0.00-0.05 (both for linear and log transformed data).

  3. Monitoring of arsenic in aquatic plants, water, and sediment of wastewater treatment ponds at the Mae Moh Lignite power plant, Thailand.

    Science.gov (United States)

    Nateewattana, Jomjun; Trichaiyaporn, Siripen; Saouy, Maliwan; Nateewattana, Jintapat; Thavornyutikarn, Prasak; Pengchai, Petch; Choonluchanon, Somporn

    2010-06-01

    Mae Moh is a risky area for arsenic contamination caused by the effluent from biowetland ponds in Mae Moh lignite-fuelled power plant. The objective of this study was to investigate the arsenic concentrations of Mae Moh biowetland ponds and determine the main factors which are important for arsenic phytoremediation in the treatment system. The result revealed that arsenic concentrations in the supernant were in the range of less than 1.0 microg As L(-1) to 2.0 microg As L(-1) while those in the sediment were in the range of 25-200 microg As kg soil(-1). Both values were below the Thailand national standard of 0.25 mg As L(-1) for water and 27 mg As kg soil(-1) for the soil. Arsenic accumulation in the biomass of 5 aquatic plants at the biowetland ponds ranged from 123.83 to 280.53 mg As kgPlant(-1). Regarding the result of regression analysis (R (2) = 0.474 to 0.954), high concentrations of organic matter and other soluble ions as well as high pH value in the sediment could significantly enhance the removal of soluble arsenic in the wetland ponds. From the regression equation of accumulated arsenic concentration in each aquatic plant, Eichhornia crassipes (Mart.) Solms. (R (2) = 0.954), Ipomoea aquatica Forsk. (R (2) = 0.850), and Typha angustifolia (L.) (R (2) = 0.841) were found to be preferable arsenic removers for wastewater treatment pond in the condition of low Eh value and high content of solid phase EC and phosphorus. On the other hand, Canna glauca (L.) (R (2) = 0.749) appeared to be favorable arsenic accumulator for the treatment pond in the condition of high Eh value and high concentration of soluble EC.

  4. Microsatellite markers forNuphar japonica(Nymphaeaceae), an aquatic plant in the agricultural ecosystem of Japan.

    Science.gov (United States)

    Kondo, Toshiaki; Watanabe, Sonoko; Shiga, Takashi; Isagi, Yuji

    2016-12-01

    Nuphar species (Nymphaeaceae) are representative aquatic plants in irrigation ponds in Japanese agricultural ecosystems. We developed 15 polymorphic microsatellite markers for N. japonica and confirmed their utility for its close relatives N. oguraensis var. akiensis and N . × saijoensis , which originated from natural hybridization between N. japonica and N. oguraensis . Genetic variation was characterized in 15 polymorphic loci in three populations of N. japonica . The average number of alleles per locus was 3.47 (range = 2-9; n = 32), and the average expected heterozygosity per locus was 0.84 (range = 0.5-1.0); 11 loci were amplified in N. oguraensis var. akiensis and 15 in N . × saijoensis . The polymorphic microsatellite markers developed in this study will be useful for investigating the levels of genetic diversity within remnant populations of Nuphar taxa and could provide a valuable tool for conservation genetics of these taxa.

  5. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae

    Science.gov (United States)

    2012-01-01

    Background Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Results Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite) and divergence time estimates (BEAST) resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma). Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges) probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Conclusions Our study has shed light

  6. Competition for light and nutrients in layered communities of aquatic plants.

    Science.gov (United States)

    van Gerven, Luuk P A; de Klein, Jeroen J M; Gerla, Daan J; Kooi, Bob W; Kuiper, Jan J; Mooij, Wolf M

    2015-07-01

    Dominance of free-floating plants poses a threat to biodiversity in many freshwater ecosystems. Here we propose a theoretical framework to understand this dominance, by modeling the competition for light and nutrients in a layered community of floating and submerged plants. The model shows that at high supply of light and nutrients, floating plants always dominate due to their primacy for light, even when submerged plants have lower minimal resource requirements. The model also shows that floating-plant dominance cannot be an alternative stable state in light-limited environments but only in nutrient-limited environments, depending on the plants' resource consumption traits. Compared to unlayered communities, the asymmetry in competition for light-coincident with symmetry in competition for nutrients-leads to fundamentally different results: competition outcomes can no longer be predicted from species traits such as minimal resource requirements ([Formula: see text] rule) and resource consumption. Also, the same two species can, depending on the environment, coexist or be alternative stable states. When applied to two common plant species in temperate regions, both the model and field data suggest that floating-plant dominance is unlikely to be an alternative stable state.

  7. Internal and external dispersal of plants by animals: an aquatic perspective on alien interference

    NARCIS (Netherlands)

    Van Leeuwen, Casper H.A.

    2018-01-01

    Many alien plants use animal vectors for dispersal of their diaspores (zoochory). If alien plants interact with native disperser animals, this can interfere with animal-mediated dispersal of native diaspores. Interference by alien species is known for frugivorous animals dispersing fruits of

  8. The oxidative toxicity of Ag and ZnO nanoparticles towards the aquatic plant Spirodela punctuta and the role of testing media parameters

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2013-09-01

    Full Text Available The toxicity effects of silver (nAg) and zinc oxide (nZnO) engineered nanoparticles (ENPs) on the duckweed Spirodela punctuta were studied to investigate the potential risks posed by these ENPs towards higher aquatic plants. The influence of media...

  9. Mapping the Distribution and Biomass of Emergent Aquatic Plants in the Sacramento-San Joaquin River Delta of California Using Landsat Imagery Analysis

    Science.gov (United States)

    Potter, Christopher

    2015-01-01

    This study evaluated the cost-effective and timely use of Landsat imagery to map and monitor emergent aquatic plant biomass and to filter satellite image products for the most probable locations of water hyacinth coverage in the Delta based on field observations collected immediately after satellite image acquisition.

  10. Accumulation of microcystin congeners in different aquatic plants and crops--a case study from lake Amatitlán, Guatemala.

    Science.gov (United States)

    Romero-Oliva, Claudia Suseth; Contardo-Jara, Valeska; Block, Tobias; Pflugmacher, Stephan

    2014-04-01

    Microcystins (MCs) fate in natural environments can lead to its transfer into aquatic organisms, e.g. aquatic plants. Moreover, lakes in several countries sustain agriculture activities posing a serious health threat for the public. The case of Lake Amatitlán in Guatemala, was addressed to better understand MCs accumulation of four aquatic plants (Polygonum portoricensis, Eichhornia crassipes, Typha sp. and Hydrilla verticillata) coexisting with Microcystis aeruginosa blooms. These findings were further corroborated with an uptake/accumulation laboratory study. Finally crop products (Solanum lycopersicum and Capsicum annuum) irrigated with lake water were also evaluated for MCs. The obtained results suggest that Lake Amatitlán is highly contaminated with MCs (intra- and extracellular 1931 and 90 µg/L, respectively). In fruits of S. lycopersicum and C. annuum a concentration of 1.16 and 1.03 µg/kg dry weight (DW), respectively could be detected. All four aquatic plants showed a high MCs uptake capacity based on obtained bioconcentration factors (BCF) 165, 18, 16 and 11, respectively. These results were further corroborated in a laboratory study with 30 percent of total MCs taken up by H. verticillata within just 7 days. Additionally it was evidenced that all plants accumulated more MC-LR than other MCs congeners. Monitoring of crop products irrigated with lake water needs further consideration. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. The oxidative toxicity of Ag and ZnO nanoparticles towards the aquatic plant Spirodela punctuta and the role of testing media parameters: Conference paper

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2013-08-01

    Full Text Available The toxicity effects of silver (nAg) and zinc oxide (nZnO) engineered nanoparticles (ENPs) on the duckweed Spirodela punctuta were studied to investigate the potential risks posed by these ENPs towards higher aquatic plants. The influence of media...

  12. Phytoremediation: role of terrestrial plants and aquatic macrophytes in the remediation of radionuclides and heavy metal contaminated soil and water.

    Science.gov (United States)

    Sharma, Sunita; Singh, Bikram; Manchanda, V K

    2015-01-01

    significantly raised the amount of heavy metals and radionuclides in it. Also, these activities are continuously increasing the area of the contaminated sites. In this context, an attempt has been made to review different modes of the phytoremediation and various terrestrial and aquatic plants which are being used to remediate the heavy metals and radionuclide-contaminated soil and aquatic systems. Natural and synthetic enhancers, those hasten the process of metal adsorption/absorption by plants, are also discussed. The article includes 216 references.

  13. International Symposium on the Biology and Management of Aquatic Plants Held in Daytona Beach, Florida on 12-16 July 1992, Volume 31

    Science.gov (United States)

    1993-01-01

    fish) limits productivity of any one vector aquatic plants due to improved transparency of water for light. (Bradley 1988). In Nepal and Afghanistan...polar leaves of Potahogeton and Elodea. C02 concentrations at the leaf surface. copy and to Mr. Brian Lewis for photography . Plant, Cell and Environ. 5...adjacent to the treated lake and downstream wetland areas ing, hyperspectral, aerial photography . MATERIALS AND METHODS The study was conducted on the

  14. Professor Volker Claus: vom o. Professor zum e-Professor

    Science.gov (United States)

    Gunzenhäuser, Rul; Taras, Christiane; Wörner, Michael

    Der Beitrag würdigt das Wirken von Professor Claus auf Gebieten des rechnerunterstützten Lehrens. Dabei wird ein Bogen von den frühen Systemen des rechnerunterstützten Lehrens über moderne Lernplattformen im Internet zu neuen Anwendungen web-basierter Systeme für das lebenslange Lehren und Lernen gespannt.

  15. Influence of sediment organic enrichment and water alkalinity on growth of aquatic isoetid and elodeid plants

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand

    2010-01-01

    ) and two elodeids (Potamogeton crispus and P. perfoliatus), we test whether organic enrichment of lake sediments has a long-lasting influence by: (i) reducing plant growth because of oxygen stress on plant roots and (ii) inhibiting growth more for isoetids than elodeids. We also test whether (iii...... because of greater CO2 supply from sediments being their main CO2 source. At higher organic enrichment, isoetid biomass was reduced, leaf chlorophyll declined up to 10-fold, root length declined from 7 to plant stress. 4. Lobelia was not affected by HCO...... development of all four species was so strongly restricted in sediments enriched with labile organic matter that plants if growing in situ may lose root anchorage. Other experiments demonstrate that this risk is enhanced by greater water content and reduced consolidation in organically rich sediments...

  16. Zinc oxide and silver nanoparticles influence the antioxidative status in a higher aquatic plant, Spirodela punctata

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2012-09-01

    Full Text Available during the 14-d exposure. The biochemical anti-oxidative status of the plant specimens were investigated using quantitative analysis of total antioxidant capacity, peroxidase and activity of catalase and superoxide dismutase. The anti-oxidative defence...

  17. Species richness of both native and invasive aquatic plants influenced by environmental conditions and human activity

    National Research Council Canada - National Science Library

    Capers, Robert S; Selsky, Roslyn; Bugbee, Gregory J; White, Jason C

    2009-01-01

    ...) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and logistic regression to determine which environmental conditions were correlated with species richness of invasive and native plants...

  18. Plant carbohydrate scavenging through tonB-dependent receptors: a feature shared by phytopathogenic and aquatic bacteria.

    Directory of Open Access Journals (Sweden)

    Servane Blanvillain

    Full Text Available TonB-dependent receptors (TBDRs are outer membrane proteins mainly known for the active transport of iron siderophore complexes in Gram-negative bacteria. Analysis of the genome of the phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc, predicts 72 TBDRs. Such an overrepresentation is common in Xanthomonas species but is limited to only a small number of bacteria. Here, we show that one Xcc TBDR transports sucrose with a very high affinity, suggesting that it might be a sucrose scavenger. This TBDR acts with an inner membrane transporter, an amylosucrase and a regulator to utilize sucrose, thus defining a new type of carbohydrate utilization locus, named CUT locus, involving a TBDR for the transport of substrate across the outer membrane. This sucrose CUT locus is required for full pathogenicity on Arabidopsis, showing its importance for the adaptation to host plants. A systematic analysis of Xcc TBDR genes and a genome context survey suggested that several Xcc TBDRs belong to other CUT loci involved in the utilization of various plant carbohydrates. Interestingly, several Xcc TBDRs and CUT loci are conserved in aquatic bacteria such as Caulobacter crescentus, Colwellia psychrerythraea, Saccharophagus degradans, Shewanella spp., Sphingomonas spp. or Pseudoalteromonas spp., which share the ability to degrade a wide variety of complex carbohydrates and display TBDR overrepresentation. We therefore propose that TBDR overrepresentation and the presence of CUT loci designate the ability to scavenge carbohydrates. Thus CUT loci, which seem to participate to the adaptation of phytopathogenic bacteria to their host plants, might also play a very important role in the biogeochemical cycling of plant-derived nutrients in marine environments. Moreover, the TBDRs and CUT loci identified in this study are clearly different from those characterized in the human gut symbiont Bacteroides thetaiotaomicron, which allow glycan foraging

  19. Cation-induced coagulation of aquatic plant-derived dissolved organic matter: Investigation by EEM-PARAFAC and FT-IR spectroscopy.

    Science.gov (United States)

    Liu, Shasha; Zhu, Yuanrong; Liu, Leizhen; He, Zhongqi; Giesy, John P; Bai, Yingchen; Sun, Fuhong; Wu, Fengchang

    2018-03-01

    Complexation and coagulation of plant-derived dissolved organic matter (DOM) by metal cations are important biogeochemical processes of organic matter in aquatic systems. Thus, coagulation and fractionation of DOM derived from aquatic plants by Ca(II), Al(III), and Fe(III) ions were investigated. Metal ion-induced removal of DOM was determined by analyzing dissolved organic carbon in supernatants after addition of these metal cations individually. After additions of metal ions, both dissolved and coagulated organic fractions were characterized by use of fluorescence excitation emission matrix-parallel factor (EEM-PARAFAC) analysis and Fourier transform infrared (FT-IR) spectroscopy. Addition of Ca(II), Fe(III) or Al(III) resulted in net removal of aquatic plant-derived DOM. Efficiencies of removal of DOM by Fe(III) or Al(III) were greater than that by Ca(II). However, capacities to remove plant-derived DOM by the three metals were less than which had been previously reported for humic materials. Molecular and structural features of plant-derived DOM fractions in associations with metal cations were characterized by changes in fluorescent components and infrared absorption peaks. Both aromatic and carboxylic-like organic matters could be removed by Ca(II), Al(III) or Fe(III) ions. Whereas organic matters containing amides were preferentially removed by Ca(II), and phenolic materials were selectively removed by Fe(III) or Al(III). These observations indicated that plant-derived DOM might have a long-lasting effect on water quality and organisms due to its poor coagulation with metal cations in aquatic ecosystems. Plant-derived DOM is of different character than natural organic matter and it is not advisable to attempt removal through addition of metal salts during treatment of sewage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Complex inter-Kingdom interactions: carnivorous plants affect growth of an aquatic vertebrate.

    Science.gov (United States)

    Davenport, Jon M; Riley, Alex W

    2017-05-01

    Coexistence of organisms in nature is more likely when phenotypic similarities of individuals are reduced. Despite the lack of similarity, distantly related taxa still compete intensely for shared resources. No larger difference between organisms that share a common prey could exist than between carnivorous plants and animals. However, few studies have considered inter-Kingdom competition among carnivorous plants and animals. In order to evaluate interactions between a carnivorous plant (greater bladderwort, Utricularia vulgaris) and a vertebrate (bluegill, Lepomis macrochirus) on a shared prey (zooplankton), we conducted a mesocosm experiment. We deployed two levels of bladderwort presence (functional and crushed) and measured bluegill responses (survival and growth). Zooplankton abundance was reduced the greatest in bluegill and functional bladderwort treatments. Bluegill survival did not differ among treatments, but growth was greatest with crushed bladderwort. Thus, bluegill growth was facilitated by reducing interference competition in the presence of crushed bladderwort. The facilitating effect was dampened, however, when functional bladderwort removed a shared prey. To our knowledge, this is one of the first studies to experimentally demonstrate interactions between a carnivorous plant and a fish. Our data suggest that carnivorous plants may actively promote or reduce animal co-occurrence from some ecosystems via facilitation or competition. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  1. Phytotoxicity of oil sands naphthenic acids and dissipation from systems planted with emergent aquatic macrophytes.

    Science.gov (United States)

    Armstrong, Sarah A; Headley, John V; Peru, Kerry M; Germida, James J

    2008-01-01

    Differences in dissipation and phytotoxicity were measured for two naphthenic acid mixtures in hydroponically grown emergent macrophytes (Typha latifolia, Phragmites australis, and Scirpus acutus). One of the naphthenic acid (NA) mixtures was extracted from tailings pond water of an oil sands operation in Fort McMurray, Alberta, Canada. The other mixture was a commercially available NA mixture. While the oil sands NA mixture was less phytotoxic to wetland plants compared to the commercially available NA mixture, they were not sequestered by wetland plants like their commercial NA counterparts. The small loss of commercial NAs from the spiked hydroponic system appeared to be selective and dependant on the specific NA compound. The results of this study indicate that plants alone may not mitigate NAs from oil sands tailings pond water. In addition, caution should be taken when making predictions on the environmental fate of oil sands naphthenic acids when using commercial NAs as surrogates.

  2. Alkalinity and trophic state regulate aquatic plant distribution in Danish lakes

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    distinct differences in the distribution of species and growth forms among the lakes. The lakes separated into five groups of characteristic species compositions. Alkalinity was the main factor responsible for the species distribution. Lakes of high alkalinity were dominated by vascular plants...... of the elodeid growth form, lakes of intermediate alkalinity contained a variety of elodeids and vascular plants of the isoetid growth form, while lakes of low alkalinity and low pH had several isoetids and bryophytes, but very few elodeids. Alkalinity is a close descriptor of the bicarbonate concentration...

  3. Zinc oxide and silver nanoparticles influence the antioxidative status in a higher aquatic plant, Spirodela punctata

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2012-09-01

    Full Text Available The authors present evidence of free radical activity and resultant anti-oxidative defence in Spirodela plants after exposure to 0.01-1000 mg/L of ZnO and Ag nanoparticles (NPs) over 96-h and 14-d. The quantification of reactive nitrogen...

  4. Designing and using phenological studies to define management strategies for aquatic plants

    Science.gov (United States)

    Scientists and managers alike have recognized that weed management activities in the past were timed more for the convenience of the applicator or response of the resource manager than in consideration of the biology of the target plant. A thorough understanding of the life history and phenology of...

  5. Digestive plasticity in Mallard ducks modulates dispersal probabilities of aquatic plants and crustaceans

    NARCIS (Netherlands)

    Charalambidou, I.; Santamaria, L.; Jansen, C.; Nolet, B.A.

    2005-01-01

    1. The consequences of plastic responses of the avian digestive tract for the potential of birds to disperse other organisms remain largely uninvestigated. 2. To explore how a seasonal diet switch in Mallard (Anas platyrhynchos L.) influences their potential to disperse plants and invertebrates, we

  6. Effects of superparamagnetic iron oxide nanoparticles on photosynthesis and growth of the aquatic plant Lemna gibba.

    Science.gov (United States)

    Barhoumi, Lotfi; Oukarroum, Abdallah; Taher, Lotfi Ben; Smiri, Leila Samia; Abdelmelek, Hafedh; Dewez, David

    2015-04-01

    Toxicity of superparamagnetic iron oxide nanoparticles (SPION) was investigated in Lemna gibba plants exposed for 7 days to Fe3O4 (SPION-1), Co0.2Zn0.8Fe2O4 (SPION-2), or Co0.5Zn0.5Fe2O4 (SPION-3) at 0, 12.5, 25, 50, 100, 200 or 400 µg mL(-1). At content, deterioration of photosystem II (PSII) functions, strong production of reactive oxygen species (ROS), and inhibition of growth rate based on fresh weight (52-59 %) or frond number (32-49 %). The performance index of PSII activity was the most sensitive biomarker of PSII functions and decreased by 83, 86, and 79 % for SPION-1, SPION-2, and SPION-3, respectively. According to the change of these biomarkers, the exposure of SPION suspensions to L. gibba caused several alterations to the entire plant cellular system, which may come from both the uptake of nanoparticles and metal ions in the soluble fraction. Our results, based on the change of several biomarkers, showed that these SPION have a complex toxic mode of action on the entire plant system and therefore affects its viability. Therefore, the plant model L. gibba was shown to be a sensitive bioindicator of SPION cellular toxicity and thus can be used in the development of a laboratory bioassay toxicity testing.

  7. Bacterial communities associated with culex mosquito larvae and two emergent aquatic plants of bioremediation importance.

    Directory of Open Access Journals (Sweden)

    Dagne Duguma

    Full Text Available Microbes are important for mosquito nutrition, growth, reproduction and control. In this study, we examined bacterial communities associated with larval mosquitoes and their habitats. Specifically, we characterized bacterial communities associated with late larval instars of the western encephalitis mosquito (Culextarsalis, the submerged portions of two emergent macrophytes (California bulrush, Schoenoplectuscalifornicus and alkali bulrush, Schoenoplectusmaritimus, and the associated water columns to investigate potential differential use of resources by mosquitoes in different wetland habitats. Using next-generation sequence data from 16S rRNA gene hypervariable regions, the alpha diversity of mosquito gut microbial communities did not differ between pond mesocosms containing distinct monotypic plants. Proteobacteria, dominated by the genus Thorsellia (Enterobacteriaceae, was the most abundant phylum recovered from C. tarsalis larvae. Approximately 49% of bacterial OTUs found in larval mosquitoes were identical to OTUs recovered from the water column and submerged portions of the two bulrushes. Plant and water samples were similar to one another, both being dominated by Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria and Verrucomicrobia phyla. Overall, the bacterial communities within C. tarsalis larvae were conserved and did not change across sampling dates and between two distinct plant habitats. Although Thorsellia spp. dominated mosquito gut communities, overlap of mosquito gut, plant and water-column OTUs likely reveal the effects of larval feeding. Future research will investigate the role of the key indicator groups of bacteria across the different developmental stages of this mosquito species.

  8. Bioaccumulation and chemical forms of cadmium, copper and lead in aquatic plants

    Directory of Open Access Journals (Sweden)

    JinZhao Hu

    2010-02-01

    Full Text Available The cadmium(Cd, copper(Cu and lead(Pb accumulation, as well as their relative content of different chemical forms in Sagittaria sagittifolia L. and Potamogeton crispus L. were determined. The results showed that both the plants had the ability to accumulate large amounts of Cd, Cu and Pb, and they absorbed metals in dose-dependent manners. The roots of S. sagittifolia appeared more sensitive to Cd and Pb than the leaves of P. crispus. The potential of Cu uptake by these two plant tissues was similar. Under the same concentration, the uptake of Cu for both the plants was higher than Pb and Cd, while that of Pb was lowest. The Cd, Cu and Pb existed with various forms in the plants. Cd and Pb were mainly in the NaCl extractable form in S. sagittifolia and P. crispus. The HAc and ethanol extractable Cu were the main forms in the root, whereas the ethanol extractable form was the dominant chemical form in the caulis and bulb of the S. sagittifolia L.

  9. The effect of herbivores on genotypic diversity in a clonal aquatic plant

    NARCIS (Netherlands)

    Hidding, B.; Meirmans, P.G.; Klaassen, M.; de Boer, T.; Ouborg, N.J.; Wagemaker, C.A.M.; Nolet, B.A.

    2014-01-01

    In clonal plants, vegetative parts may outcompete seeds in the absence of disturbance, limiting the build-up of genotypic diversity through repeated seedling recruitment (RSR). Herbivory may provide disturbance and trigger establishment of strong colonizers (seeds) at the expense of strong

  10. Plants living on the edge: colonization processes of aquatic and riparian vegetation along restored lowland streams

    NARCIS (Netherlands)

    Fraaije, R.G.A.|info:eu-repo/dai/nl/341387339

    2016-01-01

    Understanding species distributions and patterns in plant diversity is a central goal in ecology. Two contrasting concepts occur in this field, explaining species distributions by species requirements and tolerances to environmental conditions (known as ‘environmental filtering’), or by patterns in

  11. Tissue mineral nutrient content in turions of aquatic plants: does it represent a storage function?

    Czech Academy of Sciences Publication Activity Database

    Adamec, Lubomír

    2010-01-01

    Roč. 176, č. 2 (2010), s. 145-151 ISSN 1863-9135 Institutional research plan: CEZ:AV0Z60050516 Keywords : carnivorous and non-carnivorous plants * turion N, P, K, Ca and Mg content * water chemistry Subject RIV: EF - Botanics Impact factor: 1.108, year: 2010

  12. Do varying aquatic plant species affect phytoplankton and crustacean responses to a nitrogen-permethrin mixture?

    Science.gov (United States)

    Hydraulically connected wetland microcosms vegetated with either Typha latifolia or Myriophyllum aquaticum were amended with an NH4NO3 and permethrin mixture to assess the effectiveness of both plant species in mitigating ecological effects of the pollutant mixture on phytoplankton (as chlorophyll a...

  13. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding

    NARCIS (Netherlands)

    Ghahramanzadeh, R.; Esselink, G.; Kodde, L.P.; Duistermaat, H.; Valkenburg, van J.L.C.H.; Marashi, S.H.; Smulders, M.J.M.; Wiel, van de C.C.M.

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to

  14. The Effect of Aquatic Plant Abundance on Shell Crushing Resistance in a Freshwater Snail

    Science.gov (United States)

    Chaves-Campos, Johel; Coghill, Lyndon M.; García de León, Francisco J.; Johnson, Steven G.

    2012-01-01

    Most of the shell material in snails is composed of calcium carbonate but the organic shell matrix determines the properties of calcium carbonate crystals. It has been shown that the deposition of calcium carbonate is affected by the ingestion of organic compounds. We hypothesize that organic compounds not synthesized by the snails are important for shell strength and must be obtained from the diet. We tested this idea indirectly by evaluating whether the abundance of the organic matter that snails eat is related to the strength of their shells. We measured shell crushing resistance in the snail Mexipyrgus churinceanus and the abundance of the most common aquatic macrophyte, the water lily Nymphaea ampla, in ten bodies of water in the valley of Cuatro Ciénegas, Mexico. We used stable isotopes to test the assumption that these snails feed on water lily organic matter. We also measured other factors that can affect crushing resistance, such as the density of crushing predators, snail density, water pH, and the concentration of calcium and phosphorus in the water. The isotope analysis suggested that snails assimilate water lily organic matter that is metabolized by sediment bacteria. The variable that best explained the variation in crushing resistance found among sites was the local abundance of water lilies. We propose that the local amount of water lily organic matter provides organic compounds important in shell biomineralization, thus determining crushing resistance. Hence, we propose that a third trophic level could be important in the coevolution of snail defensive traits and predatory structures. PMID:22970206

  15. Copper, zinc and lead biogeochemistry in aquatic and land plants from the Iberian Pyrite Belt (Portugal) and north of Morocco mining areas.

    Science.gov (United States)

    Durães, Nuno; Bobos, Iuliu; Ferreira da Silva, Eduardo; Dekayir, Abdelilah

    2015-02-01

    The ability of aquatic (Juncus effusus L., Scirpus holoschoenus L., Thypha latifolia L. and Juncus sp.) and land (Cistus ladanifer L., Erica andevalensis C.-R., Nerium oleander L., Isatis tinctoria L., Rosmarinus officinalis L., Cynodon dactylon L. and Hordeum murinum L.) plants from Portugal (Aljustrel, Lousal and São Domingos) and Morocco (Tighza and Zeida) mining areas to uptake, translocate and tolerate heavy metals (Cu, Zn and Pb) was evaluated. The soils (rhizosphere) of the first mining area are characterized by high acidity conditions (pH 2-5), whereas from the second area, by alkaline conditions (pH 7.0-8.5). Physicochemical parameters and mineralogy of the rhizosphere were determined from both areas. Chemical analysis of plants and the rhizosphere was carried out by inductively coupled plasma emission spectrometry. The sequential chemical extraction procedure was applied for rhizosphere samples collected from both mining areas. In the acid conditions, the aquatic plants show a high capacity for Zn bioaccumulation and translocation and less for Pb, reflecting the following metal mobility sequence: Zn > Cu > Pb. Kaolinite detected in the roots by infrared spectroscopy (IR) contributed to metal fixation (i.e. Cu), reducing its translocation to the aerial parts. Lead identified in the roots of land plants (e.g. E. andevalensis) was probably adsorbed by C-H functional groups identified by IR, being easily translocated to the aerial parts. It was found that aquatic plants are more efficient for phytostabilization than bioaccumulation. Lead is more bioavailable in the rhizosphere from Morocco mining areas due to scarcity of minerals with high adsorption ability, being absorbed and translocated by both aquatic and land plants.

  16. A Professor's Work.

    Science.gov (United States)

    Melko, Matthew

    This book describes a year-long participant-observer case study of the professorship as a profession. Following an introductory chapter, each chapter examines one aspect of the professor's occupation by recounting the specific experiences of the author, a sociology professor at Wright State University (Ohio). Chapter 2 looks at the department as…

  17. Wastewater treatment plant effluent as a source of microplastics: review of the fate, chemical interactions and potential risks to aquatic organisms.

    Science.gov (United States)

    Ziajahromi, Shima; Neale, Peta A; Leusch, Frederic D L

    2016-11-01

    Wastewater treatment plant (WWTP) effluent has been identified as a potential source of microplastics in the aquatic environment. Microplastics have recently been detected in wastewater effluent in Western Europe, Russia and the USA. As there are only a handful of studies on microplastics in wastewater, it is difficult to accurately determine the contribution of wastewater effluent as a source of microplastics. However, even the small amounts of microplastics detected in wastewater effluent may be a remarkable source given the large volumes of wastewater treatment effluent discharged to the aquatic environment annually. Further, there is strong evidence that microplastics can interact with wastewater-associated contaminants, which has the potential to transport chemicals to aquatic organisms after exposure to contaminated microplastics. In this review we apply lessons learned from the literature on microplastics in the aquatic environment and knowledge on current wastewater treatment technologies, with the aim of identifying the research gaps in terms of (i) the fate of microplastics in WWTPs, (ii) the potential interaction of wastewater-based microplastics with trace organic contaminants and metals, and (iii) the risk for aquatic organisms.

  18. Quantitative distribution of aquatic plant and animal communities in the Forsmark-area

    Energy Technology Data Exchange (ETDEWEB)

    Kautsky, H.; Plantman, P.; Borgiel, M. [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    1999-12-15

    This report is a part of the SKB project 'SAFE'. The aim of SAFE is to update the previous safety analysis of SFR-1. SFR is for the repository of low and intermediate level radioactive waste. The aim of this report is to provide background information of the quantitative distribution of macroscopic (>1 mm) plants and animals on the sea floor (the phytobenthic communities) above the SFR. The phytobenthic plant and animal communities in the Bothnian Sea may constitute over half of the total production of the ecosystem in the coastal zone. Data will be used in a simulation model of the area. The attached plant and animal communities of the sea floor can be the major component to find radioactive isotopes when a leakage should occur from the SFR below the investigated area. Their ability to bioaccumulate the isotopes and the abundance of the plants and animals might to a large extent determine the amount of radionuclides that could be retained in the biological system. This might then affect the form of further dispersal of the radionuclides over larger areas, whether they are kept within and accumulated in the food chain or retained in the sediments or diluted in the water column. In the investigated area divers described the sea floor substrate and the dominating plant and animal communities along transect lines. In addition, the divers collected quantitative samples. Three transects were placed just above SFR, and two transects were placed from the shore of islands adjacent to SFR. In total, divers collected 54 quantitative samples. Also, divers collected 6 sediment cores for analysis of the organic contents and chlorophylla. The results from the divers estimates of plant and animal species distribution and cover degree, as well as the quantitative samples, indicated the area being fairly rich. An eroded moraine (boulders, stones, gravel and sand) dominated the substrate with occasional rock outcrops. At several sites, on the hard, more stable substrates

  19. Propagation and Establishment of Native Plants for Vegetative Restoration of Aquatic Ecosystems

    Science.gov (United States)

    2013-06-01

    ideal for most species. Overly sandy substrates are unsuitable as a culture medium because they are generally infertile and because added nutrients...Substrates require heat sterilization if nuisance species occur or have occurred in the past in the water body from which substrates are collected... sterilize sediments to avoid or reduce this problem. If weeds do begin to establish, removing unwanted plants requires hand weeding; and while this

  20. Enhanced metabolic and redox activity of vascular aquatic plant Lemna valdiviana under polarization in Direct Photosynthetic Plant Fuel Cell.

    Science.gov (United States)

    Hubenova, Yolina; Mitov, Mario

    2015-12-01

    In this study, duckweed species Lemna valdiviana was investigated as a photoautotrophycally grown biocatalyst in recently developed Direct Photosynthetic Plant Fuel Cell. Stable current outputs, reaching maximum of 226±11 mА/m(2), were achieved during the operating period. The electricity production is associated with electrons generated through the light-dependent reactions in the chloroplasts as well as the respiratory processes in the mitochondria and transferred to the anode via endogenous electron shuttle, synthesized by the plants as a specific response to the polarization. In parallel, a considerable increase in the content of proteins (47%) and reserve carbohydrates (44%) of duckweeds grown under polarization conditions was established by means of biochemical analyses. This, combined with the electricity generation, makes the technology a feasible approach for the duckweed farming. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Adaptive Management Using Remote Sensing and Ecosystem Modeling in Response to Climate Variability and Invasive Aquatic Plants for the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, David; Potter, Christopher; Zhang, Minghua; Madsen, John

    2017-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply and supports important ecosystem services, agriculture, and communities in Northern to Southern California. Expansion of invasive aquatic plants in the Delta coupled with impacts of changing climate and long-term drought is detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California to develop science-based, adaptive-management strategies for invasive aquatic plant in the Sacramento-San Joaquin Delta. Specific mapping tools developed utilizing satellite and airborne platforms provide regular assessments of population dynamics on a landscape scale and support both strategic planning and operational decision making for resource managers. San Joaquin and Sacramento River watersheds water quality input to the Delta is modeled using the Soil-Water Assessment Tool (SWAT) and a modified SWAT tool has been customized to account for unique landscape and management of agricultural water supply and drainage within the Delta. Environmental response models for growth of invasive aquatic weeds are being parameterized and coupled with spatial distribution/biomass density mapping and water quality to study ecosystem response to climate and aquatic plant management practices. On the water validation and operational utilization of these tools by management agencies and how they are improving decision making, management effectiveness and efficiency will be discussed. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and water resource managers make science-informed decisions regarding management and outcomes.

  2. Simultaneous determination of multiclass emerging contaminants in aquatic plants by ultrasound-assisted matrix solid-phase dispersion and GC-MS.

    Science.gov (United States)

    Aznar, Ramón; Albero, Beatriz; Sánchez-Brunete, Consuelo; Miguel, Esther; Martín-Girela, Isabel; Tadeo, José L

    2017-03-01

    A multiresidue method was developed for the simultaneous determination of 31 emerging contaminants (pharmaceutical compounds, hormones, personal care products, biocides, and flame retardants) in aquatic plants. Analytes were extracted by ultrasound-assisted matrix solid-phase dispersion (UA-MSPD) and determined by gas chromatography-mass spectrometry after sylilation, The method was validated for different aquatic plants (Typha angustifolia, Arundo donax, and Lemna minor) and a semiaquatic cultivated plant (Oryza sativa) with good recoveries at concentrations of 100 and 25 ng g -1 wet weight, ranging from 70 to 120 %, and low method detection limits (0.3 to 2.2 ng g -1 wet weight). A significant difference of the chromatographic response was observed for some compounds in neat solvent versus matrix extracts, and therefore, quantification was carried out using matrix-matched standards in order to overcome this matrix effect. Aquatic plants taken from rivers located at three Spanish regions were analyzed, and the compounds detected were parabens, bisphenol A, benzophenone-3, cyfluthrin, and cypermethrin. The levels found ranged from 6 to 25 ng g -1 wet weight except for cypermethrin that was detected at 235 ng g -1 wet weight in O. sativa samples.

  3. Effects of Co2 Concentrations and light intensity on photosynthesis of a rootless submerged plant, ceratophyllum demersum L., used for aquatic food production in bioregenerative life support systems

    Science.gov (United States)

    Kitaya, Y.; Okayama, T.; Murakami, K.; Takeuchi, T.

    Aquatic higher plants are likely to play an important role in aquatic food production modules in bioregenerative systems for producing feeds for fish, converting CO2 to O2 and remedying water quality in addition to green microalgae. In the present study, the effects of culture conditions on the net photosynthetic rate of a rootless submerged plant, Ceratophyllum demersum L., was investigated to determine the optimum culture conditions for plant function in aquatic food production modules including both plant culture and fish culture systems . The net photosynthetic rate in plants was determined by the increase in dissolved O2 concentrations in a closed vessel containing a plantlet and water. The water in the vessel was aerated sufficiently with a gas containing a known level CO 2 gas mixed with N2 gas before closing the vessel. The CO 2 concentrations in the aerating gas ranged from 0.3 to 100 mmol mol-1 . Photosynthetic photon flux density (PPFD) in the vessel ranged from 0 (dark) to 1.0 mmol m-2 s-1 , which was controlled with a metal halide lamp. Temperature was kept at 28 C. The net photosynthetic rate increased with increasing PPFD levels and was saturated at 0.2 and 0.5 mmol m-2 s-1 PPFD under CO 2 levels of 1.0 and 3.0 mmol mol-1 , respectively. The net photosynthetic rate increased with increasing CO2 levels from 0.3 to 3.0 mmol mol-1 showing the maximum value, 70 nmolO 2 gDW s at 3.0 mmol mol-1 CO2 and gradually decreased with increasing CO 2 levels from 3.0 to 100 mmol mol-1 . The results demonstrate that Ceratophyllum demersum L. could be an efficient CO 2 to O2 converter under a 3.0 mmol mol-1 CO2 level and relatively low PPFD levels in aquatic food production modules.

  4. 3- and 4-phosphorylated phosphatidylinositols in the aquatic plant Spirodela polyrhiza L.

    Science.gov (United States)

    Brearley, C A; Hanke, D E

    1992-04-01

    Labelling of Spirodela polyrhiza L. plants with [3H]inositol and [32P]Pi yielded a series of phosphoinositides which were identified as PtdIns, PtdIns4P and PtdIns(4,5)P2. In addition, systematic degradation of a phospholipid extract identified PtdIns3P. Analysis of the distribution of 32P label between the monoester and diester phosphate groups of PtdIns3P and PtdIns4P revealed differences in the labelling of the monoester phosphate, suggesting that the two PtdInsP species are not synthesized or metabolized in a co-ordinate manner.

  5. The uptake and distribution of selenium in three aquatic plants grown in Se(IV) solution.

    Science.gov (United States)

    Mechora, Spela; Stibilj, Vekoslava; Germ, Mateja

    2013-03-15

    The uptake of Se(IV) by Myriophyllum spicatum, Ceratophyllum demersum and Potamogeton perfoliatus, and the effects of Se(IV) on their physiological and biochemical characteristics were studied. Plants were cultivated outdoors under semi-controlled conditions in water solution containing Na selenite (20 μg Se L(-1) and 10 mg Se L(-1)). The higher concentration of Se lowered the photochemical efficiency of PSII in all species studied, while the lower concentration had no effect on any species. The higher concentration of Se lowered respiratory potential in M. spicatum. The response of M. spicatum and C. demersum to Se(IV) regarding chlorophylls was variable, however in the majority of cases, there was a trend of increasing the amount of chlorophylls, while in P. perfoliatus the amount of chlorophyll a decreased. The concentration of Se in plants cultured in 10 mg Se(IV) L(-1) ranged from 436 to 839 μg Se g(-1) DM in M. spicatum, 319 to 988 μg Se g(-1) DM in C. demersum and 310 to 661 μg Se g(-1) DM in P. perfoliatus. The amount of soluble Se compounds in enzyme extracts of high Se treatment was 27% in M. spicatum, 41% in C. demersum and 35% in P. perfoliatus. Se compounds were determined using HPLC-ICP-MS. It was observed that the applied Se(IV) was mainly transformed to insoluble Se. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Vitality of aquatic plants and microbial activity of sediment in an oligotrophic lake (Lake Bohinj, Slovenia

    Directory of Open Access Journals (Sweden)

    Tatjana SIMČIČ

    2011-08-01

    Full Text Available The vitality of eight macrophyte species and the microbial activity of sediment in an oligotrophic lake (Lake Bohinj, Slovenia were studied via the terminal electron transport system (ETS activity of mitochondria. The levels of ETS activity of vascular plants were as follows: Ranunculus circinatus, Myriohpyllum spicatum, Potamogeton alpinus, P. perfoliatus, P. lucens. Fontinalis antipyretica exhibited the highest ETS activity of the non-vascular plants, followed by charales Chara delicatula and C. aspera. High values enable R. circinatus, an amphibious species with rapid growth, to survive under conditions in which the water level changes throughout the season. M. spicatum, a species with broad ecological tolerance, also exhibited high ETS activity. The ETS activity of the microbial community in sediment was affected by temperature and/or the amount and origin of the organic matter. A positive correlation between the ETS activity of the sediment and that of M. spicatum and R. circinatus was measured, while negative correlations or no correlation were observed for mosses and macroalgae. The high ETS activity in sediment indicates rapid mineralization of organic matter and, in turn, sufficient nutrients for growth of macrophytes.

  7. Determination of mercury(II) in aquatic plants using quinoline-thiourea conjugates as a fluorescent probe.

    Science.gov (United States)

    Feng, Guodong; Ding, Yuanyuan; Gong, Zhiyong; Dai, Yanna; Fei, Qiang

    2013-01-01

    In this study, a quinoline-thiourea conjugate (1-phenyl-3-(quinoline-8-yl) thiourea, PQT) was synthesized and used as a fluorescence sensor to detect mercury ion. The observation is coincident with the well-documented phenomenon that a thiocarbonyl-containing group on a fluorochrome quenches the fluorescence due to the heavy atom effect of the S atom. The large fluorescence enhancement of PQT in the buffered MeCN-water mixture (1/1 v/v; HEPES 100 mM; pH 8.0) was caused by the Hg(2+) induced transformation of the thiourea function into a urea group. As such, protic solvents can be ascribed to hydrogen bond formation on the carbonyl oxygen to reduce the internal conversion rate. The fluorescence intensity of PQT was enhanced quantitatively with an increase in the concentration of mercury ion. The limit of detection of Hg(2+) was 7.5 nM. The coexistence of other metal ions with mercury had no obvious influence on the detection of mercury. A quinolone-thiourea conjugate was used as a fluorescent probe to detect Hg(2+) in aquatic plants and the experimental results were satisfactory.

  8. Direct evidence for the enhanced acquisition of phosphorus in the rhizosphere of aquatic plants: A case study on Vallisneria natans.

    Science.gov (United States)

    Xing, Xigang; Ding, Shiming; Liu, Ling; Chen, Musong; Yan, Wenming; Zhao, Liping; Zhang, Chaosheng

    2018-03-01

    There are few studies about the processes and mechanisms for aquatic plants to take up phosphorus (P) in wetland soils and sediments. Direct observation of P mobilization in rhizosphere is lacking. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were used to capture the small-scale changes of soluble reactive P (SRP) and soluble Fe, and labile P in the rhizosphere of Vallisneria natans (V. natans), respectively. The results showed 5.92- and 3.12-fold enrichments of P and Fe in the Fe plaques formed on the root surfaces, respectively, in comparison with the P and Fe concentrations in the non-rhizosphere sediments. Moreover, simultaneous releases of P and Fe appeared in rhizosphere and the SRP concentration showed up to 114-fold increases compared to the non-rhizosphere sediments. Five kinds of low-molecular weight organic acids (LMWOAs) were detected in the root exudates; oxalic acid accounted for 87.5% of the total. Extraction of Fe and P in the Fe plaques was greatly enhanced by root exudates compared to deionized water, and oxalic acid contributed to 67% and 75% of the total extracted Fe and P, respectively. The coupling processes of Fe plaque enrichment of P and oxalic acid complexation of Fe(III) led to significantly enhanced P acquisition in the rhizosphere of V. natans. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Ecological Traits of the Algae-Bearing Tetrahymena utriculariae (Ciliophora) from Traps of the Aquatic Carnivorous Plant Utricularia reflexa.

    Science.gov (United States)

    Šimek, Karel; Pitsch, Gianna; Salcher, Michaela M; Sirová, Dagmara; Shabarova, Tanja; Adamec, Lubomír; Posch, Thomas

    2017-05-01

    Trap fluid of aquatic carnivorous plants of the genus Utricularia hosts specific microbiomes consisting of commensal pro- and eukaryotes of largely unknown ecology. We examined the characteristics and dynamics of bacteria and the three dominant eukaryotes, i.e. the algae-bearing ciliate Tetrahymena utriculariae (Ciliophora), a green flagellate Euglena agilis (Euglenophyta), and the alga Scenedesmus alternans (Chlorophyta), associated with the traps of Utricularia reflexa. Our study focused on ecological traits and life strategies of the highly abundant ciliate whose biomass by far exceeds that of other eukaryotes and bacteria independent of the trap age. The ciliate was the only bacterivore in the traps, driving rapid turnover of bacterial standing stock. However, given the large size of the ciliate and the cell-specific uptake rates of bacteria we estimated that bacterivory alone would likely be insufficient to support its apparent rapid growth in traps. We suggest that mixotrophy based on algal symbionts contributes significantly to the diet and survival strategy of the ciliate in the extreme (anaerobic, low pH) trap-fluid environment. We propose a revised concept of major microbial interactions in the trap fluid where ciliate bacterivory plays a central role in regeneration of nutrients bound in rapidly growing bacterial biomass. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  10. Contribution of Wastewater Treatment Plant Effluents to Nutrient Dynamics in Aquatic Systems: A Review

    Science.gov (United States)

    Carey, Richard O.; Migliaccio, Kati W.

    2009-08-01

    Excessive nutrient loading (considering nitrogen and phosphorus) is a major ongoing threat to water quality and here we review the impact of nutrient discharges from wastewater treatment plants (WWTPs) to United States (U.S.) freshwater systems. While urban and agricultural land uses are significant nonpoint nutrient contributors, effluent from point sources such as WWTPs can overwhelm receiving waters, effectively dominating hydrological characteristics and regulating instream nutrient processes. Population growth, increased wastewater volumes, and sustainability of critical water resources have all been key factors influencing the extent of wastewater treatment. Reducing nutrient concentrations in wastewater is an important aspect of water quality management because excessive nutrient concentrations often prevent water bodies from meeting designated uses. WWTPs employ numerous physical, chemical, and biological methods to improve effluent water quality but nutrient removal requires advanced treatment and infrastructure that may be economically prohibitive. Therefore, effluent nutrient concentrations vary depending on the particular processes used to treat influent wastewater. Increasingly stringent regulations regarding nutrient concentrations in discharged effluent, along with greater freshwater demand in populous areas, have led to the development of extensive water recycling programs within many U.S. regions. Reuse programs provide an opportunity to reduce or eliminate direct nutrient discharges to receiving waters while allowing for the beneficial use of reclaimed water. However, nutrients in reclaimed water can still be a concern for reuse applications, such as agricultural and landscape irrigation.

  11. Effects of organic pollutants from wastewater treatment plants on aquatic invertebrate communities.

    Science.gov (United States)

    Bunzel, Katja; Kattwinkel, Mira; Liess, Matthias

    2013-02-01

    Pesticides are a major stressor for stream ecosystem health. They enter surface waters from diffuse agricultural sources but also from point sources such as municipal wastewater treatment plants (WWTPs). However, to date, no studies have focused on the ecological effects of pesticide-contaminated WWTP effluent on macroinvertebrate communities. On the basis of governmental monitoring data of 328 sites in Hesse, Germany, we identified insecticidal long-term effects on the structure of the macroinvertebrate community up to 3 km downstream of WWTPs. The effects were quantified using the trait-based SPEAR(pesticides) index, which has been shown to be an effective tool for identifying community effects of pesticide contamination. In addition, based on the German Saprobic Index, we revealed that WWTPs are still an important source of oxygen-depleting organic pollution, despite the extensive technological improvements in wastewater management over several centuries. In general, our findings emphasize the need to take municipal WWTPs into consideration in the management of river basins under the EU Water Framework Directive to achieve good ecological and chemical status for European streams and rivers. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Professor Martin Hairer

    Directory of Open Access Journals (Sweden)

    Martine Barons

    2015-09-01

    Full Text Available Professor Martin Hairer was one of four recipients of the 2014 Fields Medal, widely viewed as the highest honour a mathematician can receive. He is currently Regius Professor of Mathematics in the Mathematics Department at the University of Warwick. Professor Hairer has contributed significantly to the field of stochastic partial differential equations (SPDEs, which engages with interdisciplinary approaches to mathematics and physics. He has enjoyed great success communicating mathematics to a range of audiences and has also developed music editing software.In this interview, early career mathematicians, Dr Martine Barons (MJB and Dr Paul Chleboun ask Professor Hairer (MH about how his interest in mathematics developed; the awards ceremony where he received the Fields Medal; Amadeus Pro, the music software he developed and continues to maintain; and the challenges of engaging a sceptical and sometimes critical public as a mathematician.

  13. Green synthesis of gold nanoparticles using a cheap Sphaeranthus indicus extract: Impact on plant cells and the aquatic crustacean Artemia nauplii.

    Science.gov (United States)

    Balalakshmi, Chinnasamy; Gopinath, Kasi; Govindarajan, Marimuthu; Lokesh, Ravi; Arumugam, Ayyakannu; Alharbi, Naiyf S; Kadaikunnan, Shine; Khaled, Jamal M; Benelli, Giovanni

    2017-08-01

    The impact of green-fabricated gold nanoparticles on plant cells and non-target aquatic species is scarcely studied. In this research, we reported an environment friendly technique for the synthesis of gold nanoparticles (Au NPs) using the Sphaeranthus indicus leaf extract. The formation of the metal NPs was characterized by UV-Visible and FT-IR spectroscopy, XRD, SEM and TEM analyses. The UV-Visible spectra of Au NPs showed a surface plasmon resonance peak at 531nm. FT-IR analysis indicated functional bio-molecules associated with Au NPs formation. The crystalline nature of Au nanoparticles was confirmed by their XRD diffraction pattern. TEM revealed the spherical shape with a mean particle size of 25nm. Au NPs was tested at 0, 1, 3, 5, 7 and 10% doses in mitotic cell division assays, pollen germination experiments, and in vivo toxicity trials against the aquatic crustacean Artemia nauplii. Au NPs did not show any toxic effects on plant cells and aquatic invertebrates. Notably, Au NPs promoted mitotic cell division in Allium cepa root tip cells and germination of Gloriosa superba pollen grains. Au NPs showed no mortality on A. nauplii, all the tested animals showed 100% survivability. Therefore, these Au NPs have potential applications in the development of pollen germination media and plant tissue culture. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The characterization of axenic culture systems suitable for plant propagation and experimental studies of the submersed aquatic angiosperm Potamogeton pectinatus (Sago pondweed)

    Science.gov (United States)

    Ailstock, M.S.; Fleming, W.J.; Cooke, T.J.

    1991-01-01

    Clonal lines of the submersed aquatic angiosperm Potamogeton pectinatus were grown in three culture systems. The first, which used sucrose as a carbon source in a liquid medium, supported vigorous vegetative growth and can be used to propagate large numbers of plants in axenic conditions. In this culture system, plants were responsive to increasing photosynthetically active radiation (PAR) photon flux density (PFD) and were photosynthetically competent. However, their growth was heterotrophic and root development was poor. When these plants were transferred to a second nonaxenic culture system, which used 16-l buckets containing artificial sediments and tap water, growth was autotrophic and plants were morphologically identical to field-harvested P. pectinatus. The last culture system which consisted of a sand substrate and inorganic nutrient bathing solution aerated with 135 ml min-1 ambient air enhanced to 3.0% CO2 was axenic and supported autotrophic growth by plants that were also morphologically normal.

  15. Distribution and trophic transfer of short-chain chlorinated paraffins in an aquatic ecosystem receiving effluents from a sewage treatment plant.

    Science.gov (United States)

    Zeng, Lixi; Wang, Thanh; Wang, Pu; Liu, Qian; Han, Shanlong; Yuan, Bo; Zhu, Nali; Wang, Yawei; Jiang, Guibin

    2011-07-01

    Short-chain chlorinated paraffins (SCCPs) are an extremely complex group of industrial chemicals and found to be potential persistent organic pollutants (POPs), and thus have attracted extensive concern worldwide. In this study, influent, effluent, and sludge were collected from a large sewage treatment plant (STP) in Beijing, China. Water, sediment, and aquatic species were also collected from a recipient lake that receives effluents discharged from the STP. These samples were then analyzed to investigate the effect of STP effluent on distribution and trophic transfer of SCCPs in the local aquatic ecosystem. Concentrations of total SCCPs (ΣSCCPs) in lake water and surface sediments were found in the range 162-176 ng/L and 1.1-8.7 μg/g (dry weight, dw), respectively. Vertical concentration profiles of sediment cores showed ΣSCCPs decreased exponentially with increasing depth. Specific congener composition analysis in sediment layers indicated possible in situ biodegradation might be occurring. High bioaccumulation of SCCPs was observed in the sampled aquatic species. The bioaccumulation factor (BAF) generally increased with the number of chlorines in the SCCP congeners. A significantly positive correlation between lipid-normalized ΣSCCPs concentration and trophic levels (R(2) = 0.65, p < 0.05) indicate that SCCPs can biomagnify through the food chain in the effluent-receiving aquatic ecosystem.

  16. Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

    Science.gov (United States)

    Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

    2015-01-01

    The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

  17. Biotemplated Mesoporous TiO2/SiO2 Composite Derived from Aquatic Plant Leaves for Efficient Dye Degradation

    Directory of Open Access Journals (Sweden)

    Zhiying Yan

    2017-03-01

    Full Text Available The biotemplating technique is an environmental-protective high-efficiency new technology by which the resulting TiO2 may simultaneously attain the duplication of structure and self-doping elements from biotemplate materials, which is highly desirable for photocatalytic applications. In this paper, aquatic plant leaves—including reed, water hyacinth, and duckweed—were used as both templates and silicon precursors to successfully synthesize biomorphic TiO2/SiO2 composite with mesoporous structures. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, and UV–visible diffuse reflectance spectra were applied to characterize the microstructures of the samples. The results show that all TiO2/SiO2 composites are mainly composed of an anatase phase with mesoporous structure and possess high specific surface area. Compared with commercial Degussa P25 TiO2, all TiO2/SiO2 samples display intensive light-harvesting efficiency, particularly in the visible light range. The activities were evaluated by using gentian violet as a target for photocatalytic degradation experiments under simulated solar irradiation. The TiO2/SiO2 samples templated by reed and water hyacinth leaves exhibit high activity, while the TiO2/SiO2 samples obtained from duckweed are inferior to P25 in the degradation of gentian violet. A synergistic effect of SiO2 incorporation and structural construction through biotemplating is proposed to be beneficial to photocatalytic activity.

  18. β-N-Methylamino-L-alanine exposure alters defense against oxidative stress in aquatic plants Lomariopsis lineata, Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri.

    Science.gov (United States)

    Contardo-Jara, Valeska; Funke, Marc Sebastian; Peuthert, Anja; Pflugmacher, Stephan

    2013-02-01

    Four different aquatic plants, the Pteridophyte Lomariopsis lineata and the Bryophytes Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri, were tested for their capacity to absorb the neurotoxin β-N-Methylamino-L-alanine (BMAA) from water and thus their possible applicability in a "Green Liver System". After exposure to 10 and 100 μg L(-1) BMAA for 1, 3, 7 and 14 days exposure concentration of medium and tissue were analyzed by LC-MS/MS. The amount removed by the plants within only 1 day was equal to the biological degradation of 14 days. Comparing the "BMAA-removal" capacity of the 4 tested aquatic plants R. fluitans, L. lineata and T. barbieri turned out to be most effective in cleaning the water from this cyanobacterial toxin by up to 97% within 14 days. Activity of the antioxidant enzymes peroxidase (POD) and catalase (CAT), as well as biotransformation enzyme glutathione S-transferase (GST) was compared between exposed and control plants to determine possible harmful effects induced by BMAA. Whereas the Bryophytes displayed increased POD activity and subsequent adaptation when exposed to the lower concentration, as well as partly inhibited antioxidant response at the higher applied BMAA concentration, the Pteridophyte L. lineata reacted with increased POD activity during the whole experiment and increased GST activity after longer exposure for 14 days. To give a recommendation of the suitability of an aquatic plant to be used for sustainable phytoremediation of contaminated water, testing of removal capacity of specific contaminants as well as studying general physiological parameters giving hint on survivability in such environments has to be combined. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Reduction of UV-B radiation causes an enhancement of photoinhibition in high light stressed aquatic plants from New Zealand lakes.

    Science.gov (United States)

    Hanelt, Dieter; Hawes, Ian; Rae, Rowena

    2006-08-01

    Anthropogenic stratospheric ozone depletion causes an increase of UV-B radiation impinging on the earth surface, which is a threat to plants not adapted to higher UV-B irradiances. Investigations were undertaken with aquatic plants from New Zealand, where UV-irradiances are naturally higher due to the southern latitude, to compare with former results of polar species. The experiments reported in this study were undertaken with plants collected from different lakes of the South Island, with different UV transparencies. Photoinhibition was induced under controlled conditions using a sun simulator, which mimicked the natural underwater radiation spectrum. Photosynthetic activity during high light stress, and during recovery in dim light, was determined in vivo by measuring fluorescence changes, using a PAM fluorometer device. A comparison of different species showed that the extent to which UV causes an additional decrease of photosynthetic performance during high light stress varies according to the depth of growth and UV transparency of the water body. This observation fits with previous studies. However, a new finding was that some species were even more strongly inhibited when UV-B was filtered out of the simulated sun spectrum, indicating a supporting effect of the short UVR wavelength range against photoinhibition. These results were also confirmed by field experiments under natural radiation conditions. Thus, UV-B does not solely cause negative effects on photosynthesis, but it may even support recovery processes in aquatic plants adapted to a high UV-radiation environment. The latter is in contrast to earlier studies, in which UV-B radiation was considered causing only harmful effects on photosynthesis of aquatic plants.

  20. Trends of superoxide dismutase and soluble protein of aquatic plants in lakes of different trophic levels in the middle and lower reaches of the Yangtze River, China.

    Science.gov (United States)

    Wu, Ai-Ping; Cao, Te; Wu, Shi-Kai; Ni, Le-Yi; Xie, Ping

    2009-04-01

    A limnological study was carried out to determine the responses of superoxide dismutase (SOD) activities and soluble protein (SP) contents of 11 common aquatic plants to eutrophication stress. Field investigation in 12 lakes in the middle and lower reaches of the Yangtze River was carried out from March to September 2004. Our results indicated that non-submersed (emergent and floating-leafed) plants and submersed plants showed different responses to eutrophication stress. Both SOD activities of the non-submersed and submersed plants were negatively correlated with their SP contents (P plants were significantly correlated with all nitrogen variables in the water (P plants were only significantly correlated with carbon variables as well as ammonium and Secchi depth (SD) in water (P plants were decreased with decline of SD in water (P plants were mainly caused by light limitation, this showed a coincidence with the decline of macrophytes in eutrophic lakes, which might imply that the antioxidant system of the submersed plants were impaired under eutrophication stress.

  1. Spatial (bio)accumulation of pharmaceuticals, illicit drugs, plasticisers, perfluorinated compounds and metabolites in river sediment, aquatic plants and benthic organisms.

    Science.gov (United States)

    Wilkinson, John L; Hooda, Peter S; Swinden, Julian; Barker, James; Barton, Stephen

    2018-03-01

    Organic contaminants such as pharmaceuticals, personal care products (PPCPs) and other emerging contaminants (ECs) are known to persist in the aquatic environment and many are indicated as endocrine, epigenetic, or other toxicants. Typically, the study of PPCPs/ECs in the aquatic environment is limited to their occurrence dissolved in river water. In this study, accumulation and spatial distribution of thirteen PPCPs/ECs were assessed in aquatic sediment (n = 23), periphyton (biofilm, n = 8), plants Callitriche sp. (n = 8) and Potamogeton sp. (n = 7) as well as amphipod crustaceans (Gammarus pulex, n = 10) and aquatic snails (Bithynia tentaculata, n = 9). All samples (n = 65) were collected from the Hogsmill, Blackwater and Bourne Rivers in southern England. Targeted PPCPs/ECs included pharmaceuticals, plasticisers, perfluorinated compounds, illicit drugs and metabolites. Extraction from solid matrices occurred using ultrasonic-assisted extraction followed by an in-house validated method for solid-phase extraction and subsequent liquid-chromatography tandem mass-spectrometry. Field-derived bioconcentration-factors and biota-sediment accumulation-factors were determined for all studied biota. Residues of studied contaminants were found in all sediment and biota. Concentrations of contaminants were generally higher in biota than sediment. Evidence suggests that the studied aquatic plants may effectively degrade bisphenol-A into its main transformation product hydroxyacetophenone, potentially mediated by cytochrome p450 and internalisation of contaminants into the cellular vacuole. A positive association between both hydrophobicity and PFC chain length and contaminant accumulation was observed in this work. Only PFCs, plasticisers and HAP were classified as either 'bioaccumulative' or 'very bioaccumulative' using BCF criteria established by guidelines of four governments. Contaminants appeared to be differentially bioaccumulative in biota, indicating

  2. Professor Michael Levitt

    Directory of Open Access Journals (Sweden)

    Gemma-Louise Davies

    2015-10-01

    Full Text Available Professor Michael Levitt (Stanford University, USA won the 2013 Nobel Prize in Chemistry for the development of multiscale models for complex chemical systems—computational tools which can calculate the course of chemical reactions. Professor Levitt was born in Pretoria, South Africa; he came to the UK on a summer vacation aged 16, where he decided to stay and study for his A‑levels. His interest in the physics of living systems drove him to study biophysics at King’s College London, before securing a PhD position at the Laboratory of Molecular Biology in Cambridge. In the interim year between his degree and beginning his PhD, Professor Levitt worked at the Weizmann Institute of Science in Israel, where he met his future wife. They married later that year and moved to Cambridge, where their three children were born. After completing his PhD, he spent time working in Israel, Cambridge, the Salk Institute and Stanford (both California. Since 1986, he has split his time between Israel and California. Outside of science, he is a keen hiker and he is well-known to have attended the eclectic ‘Burning Man’ Festival in California.[1]Professor Levitt visited the University of Warwick to speak at the Computational Molecular Science Annual Conference in March 2015. In this interview, Dr Gemma-Louise Davies, an Institute of Advanced Study Global Research Fellow, spoke to Professor Levitt about the importance of Interdisciplinarity in his field, role models in Academia, and his plans for the future.Image: Professor Michael Levitt (left with Dr Scott Habershon (right, organiser of the 2015 Computational Molecular Science Annual Conference during his visit to the University of Warwick in March 2015.[1] ‘Burning Man’ is a unique annual festival dedicated to community, art, music, self-expression and self-reliance. Tens of thousands of people flock to this temporary metropolis built in the Californian desert.

  3. Effects of CO 2 concentration and light intensity on photosynthesis of a rootless submerged plant, Ceratophyllumdemersum L., used for aquatic food production in bioregenerative life support systems

    Science.gov (United States)

    Kitaya, Y.; Okayama, T.; Murakami, K.; Takeuchi, T.

    In addition to green microalgae, aquatic higher plants are likely to play an important role in aquatic food production modules in bioregenerative systems for producing feed for fish, converting CO 2 to O 2 and remedying water quality. In the present study, the effects of culture conditions on the net photosynthetic rate of a rootless submerged plant, Ceratophyllum demersum L., was investigated to determine the optimum culture conditions for maximal function of plants in food production modules including both aquatic plant culture and fish culture systems. The net photosynthetic rate in plants was determined by the increase in dissolved O 2 concentrations in a closed vessel containing a plantlet and water. The water in the vessel was aerated sufficiently with a gas containing a known concentration of CO 2 gas mixed with N 2 gas before closing the vessel. The CO 2 concentrations in the aerating gas ranged from 0.3 to 10 mmol mol -1. Photosynthetic photon flux density (PPFD) in the vessel ranged from 0 (dark) to 1.0 mmol M -2 s -1, which was controlled with a metal halide lamp. Temperature was kept at 28°C. The net photosynthetic rate increased with increasing PPFD levels and was saturated at 0.2 and 0.5 mmol m -2 s -1 PPFD under CO 2 levels of 1.0 and 3.0 mmol mol -1, respectively. The net photosynthetic rate increased with increasing CO 2 levels from 0.3 to 3.0 mmol mol -1 showing the maximum value, 75 nmolO 2 gDW -1 s -1, at 2-3 mmol mol -1 CO 2 and gradually decreased with increasing CO 2 levels from 3.0 to 10 mmol mol -1. The results demonstrate that C. demersum could be an efficient CO 2 to O 2 converter under a 2.0 mmol mol -1 CO 2 level and relatively low PPFD levels in aquatic food production modules.

  4. Effects of CO2 concentration and light intensity on photosynthesis of a rootless submerged plant, Ceratophyllum demersum L., used for aquatic food production in bioregenerative life support systems

    Science.gov (United States)

    Kitaya, Y.; Okayama, T.; Murakami, K.; Takeuchi, T.

    2003-01-01

    In addition to green microalgae, aquatic higher plants are likely to play an important role in aquatic food production modules in bioregenerative systems for producing feed for fish, converting CO2 to O2 and remedying water quality. In the present study, the effects of culture conditions on the net photosynthetic rate of a rootless submerged plant, Ceratophyllum demersum L., was investigated to determine the optimum culture conditions for maximal function of plants in food production modules including both aquatic plant culture and fish culture systems. The net photosynthetic rate in plants was determined by the increase in dissolved O2 concentrations in a closed vessel containing a plantlet and water. The water in the vessel was aerated sufficiently with a gas containing a known concentration of CO2 gas mixed with N2 gas before closing the vessel. The CO2 concentrations in the aerating gas ranged from 0.3 to 10 mmol mol-1. Photosynthetic photon flux density (PPFD) in the vessel ranged from 0 (dark) to 1.0 mmol m-2 s-1, which was controlled with a metal halide lamp. Temperature was kept at 28 degrees C. The net photosynthetic rate increased with increasing PPFD levels and was saturated at 0.2 and 0.5 mmol m-2 s-1 PPFD under CO2 levels of 1.0 and 3.0 mmol mol-1, respectively. The net photosynthetic rate increased with increasing CO2 levels from 0.3 to 3.0 mmol mol-1 showing the maximum value, 75 nmol O2 gDW-1 s-1, at 2-3 mmol mol-1 CO2 and gradually decreased with increasing CO2 levels from 3.0 to 10 mmol mol-1. The results demonstrate that C. demersum could be an efficient CO2 to O2 converter under a 2.0 mmol mol-1 CO2 level and relatively low PPFD levels in aquatic food production modules. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  5. Professor Wolfgang Panofsky

    CERN Multimedia

    2007-01-01

    "Professor Wolfgang panofsky, who died on September 24 aged 88, was a particle physicists and director of the Stanford Linear Accelerator Centre (SLAC) in California; with Jack Steinberger, he was the first to isolate the neutral pi meson, one of the subatomic particles which had been predicted by theoretical scientists to account for the strng force which binds the nuclei of atoms." (1 page)

  6. Professor Tiina Tasmuth Helsingis

    Index Scriptorium Estoniae

    2000-01-01

    Tervisekasvatuse õppetooli professor Tiina Tasmuth osales 11.-14. juunini Helsingis toimunud rahvusvahelise konverentsi "2nd Psycho-Social Impacts of Breast Cancer" töös ning esines ettekandega teemal "Chronic post-treatment symptoms in patients with breast cancer" : [täistekst

  7. Professor og DMI

    DEFF Research Database (Denmark)

    Kaas, Eigil

    2010-01-01

    oplever meget lave temperaturer - og for Danmarks vedkommende en usædvanlig lang periode med vintervejr. Forklaringen kommer fra professor Eigil Kaas fra Niels Bohr Instituttet ved Københavns Universitet. Han forklarer til jp.dk, at vintervejret dog er betinget af den mere eller mindre tilfældige måde...

  8. Assessing and Managing the Current and Future Pest Risk from Water Hyacinth, (Eichhornia crassipes, an Invasive Aquatic Plant Threatening the Environment and Water Security.

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Understanding and managing the biological invasion threats posed by aquatic plants under current and future climates is a growing challenge for biosecurity and land management agencies worldwide. Eichhornia crassipes is one of the world's worst aquatic weeds. Presently, it threatens aquatic ecosystems, and hinders the management and delivery of freshwater services in both developed and developing parts of the world. A niche model was fitted using CLIMEX, to estimate the potential distribution of E. crassipes under historical and future climate scenarios. Under two future greenhouse gas emission scenarios for 2080 simulated with three Global Climate Models, the area with a favourable temperature regime appears set to shift polewards. The greatest potential for future range expansion lies in Europe. Elsewhere in the northern hemisphere temperature gradients are too steep for significant geographical range expansion under the climate scenarios explored here. In the Southern Hemisphere, the southern range boundary for E. crassipes is set to expand southwards in Argentina, Australia and New Zealand; under current climate conditions it is already able to invade the southern limits of Africa. The opportunity exists to prevent its spread into the islands of Tasmania in Australia and the South Island of New Zealand, both of which depend upon hydroelectric facilities that would be threatened by the presence of E. crassipes. In Europe, efforts to slow or stop the spread of E. crassipes will face the challenge of limited internal biosecurity capacity. The modelling technique demonstrated here is the first application of niche modelling for an aquatic weed under historical and projected future climates. It provides biosecurity agencies with a spatial tool to foresee and manage the emerging invasion threats in a manner that can be included in the international standard for pest risk assessments. It should also support more detailed local and regional

  9. Assessing and Managing the Current and Future Pest Risk from Water Hyacinth, (Eichhornia crassipes), an Invasive Aquatic Plant Threatening the Environment and Water Security.

    Science.gov (United States)

    Kriticos, Darren J; Brunel, Sarah

    2016-01-01

    Understanding and managing the biological invasion threats posed by aquatic plants under current and future climates is a growing challenge for biosecurity and land management agencies worldwide. Eichhornia crassipes is one of the world's worst aquatic weeds. Presently, it threatens aquatic ecosystems, and hinders the management and delivery of freshwater services in both developed and developing parts of the world. A niche model was fitted using CLIMEX, to estimate the potential distribution of E. crassipes under historical and future climate scenarios. Under two future greenhouse gas emission scenarios for 2080 simulated with three Global Climate Models, the area with a favourable temperature regime appears set to shift polewards. The greatest potential for future range expansion lies in Europe. Elsewhere in the northern hemisphere temperature gradients are too steep for significant geographical range expansion under the climate scenarios explored here. In the Southern Hemisphere, the southern range boundary for E. crassipes is set to expand southwards in Argentina, Australia and New Zealand; under current climate conditions it is already able to invade the southern limits of Africa. The opportunity exists to prevent its spread into the islands of Tasmania in Australia and the South Island of New Zealand, both of which depend upon hydroelectric facilities that would be threatened by the presence of E. crassipes. In Europe, efforts to slow or stop the spread of E. crassipes will face the challenge of limited internal biosecurity capacity. The modelling technique demonstrated here is the first application of niche modelling for an aquatic weed under historical and projected future climates. It provides biosecurity agencies with a spatial tool to foresee and manage the emerging invasion threats in a manner that can be included in the international standard for pest risk assessments. It should also support more detailed local and regional management.

  10. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Selected Life History Information of Animal Species on Lake Conway, Florida.

    Science.gov (United States)

    1982-08-01

    of the problem aquatic plant hydrilla. Information developed in this report will1i(Continued) DD FOR W~S13 Enon r mOF N Vs is NossLeftUfn’n ASECURITY...and commercial d. Unknown management potential e. Not sensitive f. Omnivorous , including terres- trial and aquatic insects, macrocrustaceans, fish...threat- ened or endangered lists c. Not recreational or commercial d. Unknown management potential e. Not sensitive f. Largely vegetarian in diet h. i

  11. Professors' Observations on Their Work.

    Science.gov (United States)

    Myers, Betty; Mager, Gerald M.

    Previous studies of professors of education have noted what activities comprised the work of being a professor, how professors allocated time to the various work tasks, how they would have preferred to allocate time, and insights they had about their work. In this study, parallel data were gathered on the broader education professoriate. Survey…

  12. Biological invasion by a benthivorous fish reduced the cover and species richness of aquatic plants in most lakes of a large North American ecoregion.

    Science.gov (United States)

    Bajer, Przemyslaw G; Beck, Marcus W; Cross, Timothy K; Koch, Justine D; Bartodziej, William M; Sorensen, Peter W

    2016-12-01

    Biological invasions are projected to be the main driver of biodiversity and ecosystem function loss in lakes in the 21st century. However, the extent of these future losses is difficult to quantify because most invasions are recent and confounded by other stressors. In this study, we quantified the outcome of a century-old invasion, the introduction of common carp to North America, to illustrate potential consequences of introducing non-native ecosystem engineers to lakes worldwide. We used the decline in aquatic plant richness and cover as an index of ecological impact across three ecoregions: Great Plains, Eastern Temperate Forests and Northern Forests. Using whole-lake manipulations, we demonstrated that both submersed plant cover and richness declined exponentially as carp biomass increased such that plant cover was reduced to plant species richness along with Secchi depth, lake area and human development of lake watersheds. Model parameters showed that carp reduced species richness to a similar degree across lakes of various Secchi depths and surface areas. In regions dominated by carp (e.g., Great Plains), carp had a stronger impact on plant richness than human watershed development. Overall, our analysis shows that the introduction of common carp played a key role in driving a severe reduction in plant cover and richness in a majority of Great Plains lakes and a large portion of Eastern Temperate Forests lakes in North America. © 2016 John Wiley & Sons Ltd.

  13. Ecobiophysical Aspects on Nanosilver Biogenerated from Citrus reticulata Peels, as Potential Biopesticide for Controlling Pathogens and Wetland Plants in Aquatic Media

    Directory of Open Access Journals (Sweden)

    Marcela Elisabeta Barbinta-Patrascu

    2017-01-01

    Full Text Available In recent years, a considerable interest was paid to ecological strategies in management of plant diseases and plant growth. Metallic nanoparticles (MNPs gained considerable interest as alternative to pesticides due to their interesting properties. Green synthesis of MNPs using plant extracts is very advantageous taking into account the fact that plants are easily available and eco-friendly and possess many phytocompounds that help in bioreduction of metal ions. In this research work, we phytosynthesized AgNPs from aqueous extract of Citrus reticulata peels, with high antioxidant, antibacterial, and antifungal potential. These “green” AgNPs were characterized by modern biophysical methods (absorption and FTIR spectroscopy, AFM, and zeta potential measurements. The nanobioimpact of Citrus-based AgNPs on four invasive wetland plants, Cattail (Typha latifolia, Flowering-rush (Butomus umbellatus, Duckweed (Lemna minor, and Water-pepper (Polygonum hydropiper, was studied by absorption spectroscopy, by monitoring the spectral signature of chlorophyll. The invasive plants exhibited different behavior under AgNP stress. Deep insights were obtained from experiments conducted on biomimetic membranes marked with chlorophyll a. Our results pointed out the potential use of Citrus-based AgNPs as alternative in controlling pathogens in aqueous media and in management of aquatic weeds growth.

  14. Using Satellite Remote Sensing to Map Changes in Aquatic Invasive Plant Cover in the Sacramento-San Joaquin River Delta of California

    Science.gov (United States)

    Potter, Christopher

    2017-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed a 80% overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  15. Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake

    Directory of Open Access Journals (Sweden)

    Kun Li

    2017-09-01

    Full Text Available The degradation of water quality in lakes and its negative effects on freshwater ecosystems have become a serious problem worldwide. Exploring the dynamics in the associated factors is essential for water pollution management and control. GIS interpolation, principal component analysis (PCA and multivariate statistical techniques were used to identify the main pollution sources in different areas of Honghu Lake. The results indicate that the spatial distribution of the concentrations of total nitrogen (TN, total phosphate (TP, ammonia nitrogen (NH4+–N, and permanganate index (CODMn have similar characteristics and that their values gradually increased from south to north during the three seasons in Honghu Lake. The major influencing factors of water quality varied across the different areas and seasons. The relatively high concentrations of TN and TP, which might limit the growth of submerged aquatic plants, were mainly caused by anthropogenic factors. Our work suggests that spatial analyses combined with PCA are useful for investigating the factors that influence water quality and submerged aquatic plant biomass in different areas of a lake. These findings provide sound information for the future water quality management of the lake or even the entire lake basin.

  16. Synergistic effects of heavy metal pollutants on senescence in submerged aquatic plants. [Potamogeton pectinatus L. , Vallisneria spiralis L. , Hydrialla Verticillata (L. f. ) Royle

    Energy Technology Data Exchange (ETDEWEB)

    Jana, S.; Choudhuri, M.A.

    1984-01-01

    The effects of many combinations of toxic concentrations of heavy metal pollutants, viz., mercuric chloride, lead acetate, cadmium chloride and cupric sulphate, on the senescence of isolated mature leaves of submerged aquatic plants, Potamogeton pectinatus L., Vallisneria spiralis L., and Hydrilla Verticillata (L.f.) Royle were studied. All of the combinations of heavy metal pollutants caused senescence in all three species by decreasing chlorophyll, DNA, RNA, protein and dry wt, and increasing free amino acid, tissue permeability, the activities of protease and RNase, and the ratio of acid to alkaline pyrophosphatase activity over control values. The effects were highest in Potamogeton and lowest in Hydrilla. The degree of senescence in the three submerged plants by combinations of toxic concentrations of heavy metal pollutants is much higher due to synergism than that by individual heavy metal pollutants.

  17. 8 Aquatic Insect Fauna.cdr

    African Journals Online (AJOL)

    Administrator

    period of one year during the wet, dry and intermediate seasons for aquatic insect fauna. Fifteen sampling sites were chosen based on certain ... objects as well as aquatic plants and leaves. Fifty seven (57) species of aquatic insects .... Both litter and household waste littered the river bank. D4 UP. Sampling was done at ...

  18. Loss of heterophylly in aquatic plants: not ABA-mediated stress but exogenous ABA treatment induces stomatal leaves in Potamogeton perfoliatus.

    Science.gov (United States)

    Iida, Satoko; Ikeda, Miyuki; Amano, Momoe; Sakayama, Hidetoshi; Kadono, Yasuro; Kosuge, Keiko

    2016-09-01

    Heterophyllous aquatic plants produce aerial (i.e., floating and terrestrial) and submerged leaves-the latter lack stomata-while homophyllous plants contain only submerged leaves, and cannot survive on land. To identify whether differences in morphogenetic potential and/or physiological stress responses are responsible for variation in phenotypic plasticity between two plants types, responses to abscisic acid (ABA) and salinity stress were compared between the closely related, but ecologically diverse pondweeds, Potamogeton wrightii (heterophyllous) and P. perfoliatus (homophyllous). The ABA-treated (1 or 10 μM) P. wrightii plants exhibited heterophylly and produced leaves with stomata. The obligate submerged P. perfoliatus plants were able to produce stomata on their leaves, but there were no changes to leaf shape, and stomatal production occurred only at a high ABA concentration (10 μM). Under salinity stress conditions, only P. wrightii leaves formed stomata. Additionally, the expression of stress-responsive NCED genes, which encode a key enzyme in ABA biosynthesis, was consistently up-regulated in P. wrightii, but only temporarily in P. perfoliatus. The observed species-specific gene expression patterns may be responsible for the induction or suppression of stomatal production during exposure to salinity stress. These results suggest that the two Potamogeton species have an innate morphogenetic ability to form stomata, but the actual production of stomata depends on ABA-mediated stress responses specific to each species and habitat.

  19. Professor I I Glass A Tribute and Memorial

    CERN Document Server

    Igra, Ozer

    2013-01-01

    The book provides personal memories along with description of scientific works written by ex-graduate students and research associates of the late Professor Glass. The described research work covers a wide range of shock wave phenomena, resulting from seeds planted by Professor Glass. Professor Glass was born in Poland in 1918. He immigrated together with his parents to Canada at the age of 12 and received all his professional education at the University of Toronto, Canada. He became a world recognized expert in shock wave phenomena, and during his 45 years of active research he supervised more than 125 master and doctoral students, post-doctoral fellows and visiting research associates. In this book seven of his past students/research-associates describe their personal memories of Professor Glass and present some of their investigations in shock wave phenomena which sprung from their past work with Professor Glass. Specifically, these investigations include underwater shock waves, shock/bubble interaction, m...

  20. Interactions of metal-based engineered nanoparticles with aquatic higher plants: A review of state of current knowledge

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2016-01-01

    Full Text Available . Dissolution appears to be a key mechanism driving bioaccumulation of ENPs, whereas nanoparticulates often adsorb to plant surfaces with minimal internalisation. However, few reports document the internalisation of ENPs by plants, thus the role...

  1. Proceedings, Annual Meeting (27th), Aquatic Plant Control Research Program Held in Bellevue, Washington on 16-19 November 1992

    Science.gov (United States)

    1993-09-01

    Nelson, WES 9:45 a.m. Break 10:15 a.m. Bioassays of Plant Growth Regulator Activity (32578) * Carole A. Lembi, Purdue University West Lafayette...polyphenols in transgenic Deevers for a wide range of technical and plants overexpressing peroxidase," Plant practical assistance in this study. Physiol. 96...grown under field conditions in a mesocosm toxic effects on other plant functions. In labo- tank system. ratory bioassays , stem elongation of Eurasian

  2. Effects of TiO2nanoparticles on the aquatic plant Spirodela polyrrhiza: Evaluation of growth parameters, pigment contents and antioxidant enzyme activities.

    Science.gov (United States)

    Movafeghi, Ali; Khataee, Alireza; Abedi, Mahboubeh; Tarrahi, Roshanak; Dadpour, Mohammadreza; Vafaei, Fatemeh

    2018-02-01

    Plants are essential components of all ecosystems and play a critical role in environmental fate of nanoparticles. However, the toxicological impacts of nanoparticles on plants are not well documented. Titanium dioxide nanoparticles (TiO 2 -NPs) are produced worldwide in large quantities for a wide range of purposes. In the present study, the uptake of TiO 2 -NPs by the aquatic plant Spirodela polyrrhiza and the consequent effects on the plant were evaluated. Initially, structural and morphological characteristics of the used TiO 2 -NPs were determined using XRD, SEM, TEM and BET techniques. As a result, an anatase structure with the average crystalline size of 8nm was confirmed for the synthesized TiO 2 -NPs. Subsequently, entrance of TiO 2 -NP S to plant roots was verified by fluorescence microscopic images. Activity of a number of antioxidant enzymes, as well as, changes in growth parameters and photosynthetic pigment contents as physiological indices were assessed to investigate the effects of TiO 2 -NPs on S. polyrrhiza. The increasing concentration of TiO 2 -NPs led to the significant decrease in all of the growth parameters and changes in antioxidant enzyme activities. The activity of superoxide dismutase enhanced significantly by the increasing concentration of TiO 2 -NPs. Enhancement of superoxide dismutase activity could be explained as promoting antioxidant system to scavenging the reactive oxygen species. In contrast, the activity of peroxidase was notably decreased in the treated plants. Reduced peroxidase activity could be attributed to either direct effect of these particles on the molecular structure of the enzyme or plant defense system damage due to reactive oxygen species. Copyright © 2017. Published by Elsevier B.V.

  3. Professor Stewart's incredible numbers

    CERN Document Server

    Stewart, Ian

    2015-01-01

    Ian Stewart explores the astonishing properties of numbers from 1 to10 to zero and infinity, including one figure that, if you wrote it out, would span the universe. He looks at every kind of number you can think of - real, imaginary, rational, irrational, positive and negative - along with several you might have thought you couldn't think of. He explains the insights of the ancient mathematicians, shows how numbers have evolved through the ages, and reveals the way numerical theory enables everyday life. Under Professor Stewart's guidance you will discover the mathematics of codes,

  4. Enhanced phytoremediation of cadmium polluted water through two aquatic plants Veronica anagallis-aquatica and Epilobium laxum.

    Science.gov (United States)

    Ahmad, Ayaz; Hadi, Fazal; Ali, Nasir; Jan, Amin Ullah

    2016-09-01

    Toxic metal-contaminated water is a major threat to sustainable agriculture and environment. Plants have the natural ability to absorb and concentrate essential elements in its tissues from water solution, and this ability of plants can be exploited to remove heavy/toxic metals from the contaminated water. For this purpose, two plants Veronica anagallis-aquatica and Epilobium laxum were hydroponically studied. The effect of different fertilizers (NPK) and plant growth regulators (GA3 and IAA) were evaluated on growth, biomass, free proline, phenolics, and chlorophyll contents, and their role in Cd phytoaccumulation was investigated. Results showed that in both plants, fertilizer addition to media (treatment T4) produced the highest significant increase in growth, biomass (fresh and dry), cadmium concentration, proline, phenolics, and chlorophyll concentrations. The significant effect of GA3 in combination with NPK foliar spray (treatment T12) was observed on most of the growth parameters, Cd concentration, and proline and phenolic contents of the plants. The free proline and total phenolics showed positive correlation with cadmium concentration within plant tissues. Proline showed significantly positive correlation with phenolic contents of root and shoot. Veronica plant demonstrated the hyperaccumulator potential for cadmium as bioconcentration factor (BCF >1) which was much higher than 1, while Epilobium plant showed non-hyperaccumulator potential. It is recommended for further study to investigate the role of Veronica plant for other metals and to study the role of phenolics and proline contents in heavy metal phytoextraction by various plant species.

  5. Hygienic and microbiological influences exerted on natural water biotopes by algae and the growth of water plants. 2. Communication: improvement of the chemical and bacteriological water quality by the natural growth of aquatic plants (author's transl)

    Energy Technology Data Exchange (ETDEWEB)

    Graef, W.; Kersch, D.; Pawlofsky, C.M.

    1981-12-01

    For a natural pond, whose waters are used for recreational purposes (swimming) and are subject to waste water inflow, the biological purifying function of a zone overgrown with reeds and aquatic plants was ascertained by means of chemical and bacteriological water quality parameters. In the years from 1975 to 1980 the contents of ammonia, nitrites, nitrates, phosphates and chlorides as well as the colony counts (CFU/ml), the coli titres and the content of fruiting myxobacteria were determined from water samples, both during the lush-growth summer period and the low-growth winter season. The location of the 6 sampling points systematically extended from the sewage outlet via the tributary ditch, in front of and behind the natural growth zone as far as the swimming waters. The test series showed - that in the tributary ditch and especially during the passage through the upper water zone densely overgrown with aquatic plants, the proportion of degradable nitrogen compounds and phosphates is distinctly reduced beyond the extent of reduction by dilution processes, - that the colony counts in the effluent water as well as the content of E. coli and of the fruiting myxobacteria, which act as indirect faecal indicator, are also reduced considerably, - that the biological purifying of the vegetation zone is definitely higher in summer than during the low-growth winter months. From this the conclusion can be drawn that for maintaining and furthering an adequate water quality of recreational waters compromised by waste water, the preservation of the naturally growing aquatic plants both in the water itself and on the banks is absolutely necessary.

  6. Professor Alex Callinicos

    Directory of Open Access Journals (Sweden)

    Ali Saqer

    2016-04-01

    Full Text Available Professor Alex Callinicos is a renowned social theorist and scholar of international political economy. He conducts research on Marx and Marxism, European social and political theory, contemporary political philosophy, critical theory, historiography, and international political economy. His work provides invaluable insights on issues of race and racism, social justice, the Third Way, imperialism, austerity, and EU politics, among many other fascinating contemporary issues. Alex studied Philosophy, Politics, and Economics at Balliol College, Oxford, and Philosophy of Science at the London School of Economics before writing a DPhil on Marx's Capital, also at Balliol. He was a Junior Research Fellow in Contemporary Social Thought at St Peter's College, Oxford from 1979 to 1981, after which he taught social and political theory at the Department of Politics at the University of York until 2005, when he moved to King's College London. Alex is currently the Professor of European Studies at King's and editor of International Socialism. Alex has been an active contributor to the development of the movement for another globalization, participating in the World Social Forum and an animator of the European Social Forum. Among his best known books are The Revolutionary Ideas of Karl Marx (1983, Against Postmodernism (1990, Social Theory (1999, An Anti-Capitalist Manifesto (2003, The Resources of Critique (2006, Imperialism and Global Political Economy (2009. His most recent book is entitled Deciphering Capital: Marx’s Capital and its Destiny (2014.

  7. Industrial water treatment with heavy metals through zeolites and bioremediation systems with aquatic plants especially Eichhornia crassipes. State of art review

    Directory of Open Access Journals (Sweden)

    Uriel Fernando Carreño-Sayago

    2014-12-01

    Full Text Available In this review we explore different opportunities to use a cheap natural material for removing and retention of heavy metals from polluted waters by waste of different processes. Two research systems will be addressed: the first through a material known as zeolite or more generally porous  luminosilicates, which may be synthesized or extracted from the mines of clays and minerals, being used in its natural state or after modification processes and doping. The other mechanism is bioremediation through algae, some bacteria and especially aquatic plants such as Eichhornia crassipes (water hyacinth. We will evaluate the viability of joining these two types complementing each other. Investigations into the feasibility of Eichhornia crassipes (water hyacinth as feedstock for biofuels are also reviewed.

  8. A compilation of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways and the suggested default values for the RESRAD code

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.Y.; Biwer, B.M.; Yu, C.

    1993-08-01

    The ongoing development and revision of the RESRAD computer code at Argonne National Laboratory requires update of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways. Default values for these transfer factors used in published radiological assessment reports are compiled and compared with values used in RESRAD. The differences among the reported default values used in different radiological assessment codes and reports are also discussed. In data comparisons, values used in more recent reports are given more weight because more recent experimental work tends to be conducted under better-defined laboratory or field conditions. A new default value is suggested for RESRAD if one of the following conditions is met: (1) values used in recent reports are an order of magnitude higher or lower than the default value currently used in RESRAD, or (2) the same default value is used in several recent radiological assessment reports.

  9. Above- and below-ground vertebrate herbivory may each favour a different subordinate species in an aquatic plant community

    NARCIS (Netherlands)

    Hidding, B.; Nolet, B.A.; De Boer, T.; De Vries, P.P.; Klaassen, M.R.J.

    2010-01-01

    At least two distinct trade-offs are thought to facilitate higher diversity in productive plant communities under herbivory. Higher investment in defence and enhanced colonization potential may both correlate with decreased competitive ability in plants. Herbivory may thus promote coexistence of

  10. Ammonium, microcystins, and hypoxia of blooms in eutrophic water cause oxidative stress and C-N imbalance in submersed and floating-leaved aquatic plants in Lake Taihu, China.

    Science.gov (United States)

    Zhang, Meng; Wang, Zhengqi; Xu, Jun; Liu, Yaqin; Ni, Leyi; Cao, Te; Xie, Ping

    2011-01-01

    The heavy bloom of cyanobacteria is a disastrous consequence of freshwater eutrophication, and the bloom is highly toxic due to its secondary metabolites called microcystins (MCs). The release of organic substances from dense blooms causes an increase in NH4+ and decrease in oxygen in lake water. In the present study, the dynamics of physio-biochemical responses of five aquatic macrophytes to MCs and NH4+ stresses in Meiliang Bay were evaluated. The bay is one of the most seriously eutrophized areas dominated by the toxic cyanobacteria of Lake Taihu, China. The results demonstrate that aquatic macrophytes in Meiliang Bay are subjected to successive external stresses. From January to May, they are subjected to high NH4+ stress (>0.56 mg L(-1)), whereas from June to September or during dense blooms, the macrophytes experience both MC proliferation and moderate NH4+ toxicity (>0.3 mg L(-1)). In August, high NH4+ stress occurs along with hypoxia stress, whereas from September to December, the macrophytes experience moderate NH4+ stress, causing a serious imbalance in C-N metabolism and oxidative stress. Between the two aquatic plant life forms, floating-leaved plants are more resistant to the stresses of eutrophication than are submersed plants. Elevated MCs in the water column can aggravate oxidative stress and suppress the soluble protein contents of aquatic plants. High NH4+ in the water causes severe C and N imbalance in submersed macrophytes because of considerable carbon consumption for free amino acid synthesis. The superoxide dismutase activities of submersed macrophytes are suppressed by low light penetrating the eutrophic water, which might impair the antioxidative function of the plants. The findings of this study provide mainly field evidence that reveals the physical, chemical, and biological stresses on aquatic plants in bloom-prevailed eutrophic lakes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. A controlled aquatic ecological life support system (CAELSS) for combined production of fish and higher plant biomass suitable for integration into a lunar or planetary base.

    Science.gov (United States)

    Blum, V; Andriske, M; Eichhorn, H; Kreuzberg, K; Schreibman, M P

    1995-10-01

    Based on the construction principle of the already operative Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) the concept of an aquaculture system for combined production of animal and plant biomass was developed. It consists of a tank for intensive fish culture which is equipped with a feeding lock representing also a trap for biomass removal followed by a water recycling system. This is an optimized version of the original C.E.B.A.S. filters adapted to higher water pollutions. It operates in a fully biological mode and is able to convert the high ammonia ion concentrations excreted by the fish gills into nitrite ions. The second biomass production site is a higher plant cultivator with an internal fiber optics light distributor which may utilize of solar energy. The selected water plant is a tropical rootless duckweed of the genus Wolffia which possesses a high capacity in nitrate elimination and is terrestrially cultured as a vegetable for human nutrition in Southeast Asia. It is produced in an improved suspension culture which allows the removal of excess biomass by tangential centrifugation. The plant cultivator is able to supply the whole system with oxygen for respiration and eliminates vice versa the carbon dioxide exhaled by the fish via photosynthesis. A gas exchanger may be used for emergency purposes or to deliver excess oxygen into the environment and may be implemented into the air regeneration system of a closed environment of higher order. The plant biomass is fed into a biomass processor which delivers condensed fresh and dried biomass as pellets. The recovered water is fed back into the aquaculture loop. The fresh plants can be used for human nutrition immediately or can be stored after sterilization in an adequate packing. The dried Wolffia pellets are collected and brought into the fish tank by an automated feeder. In parallel the water from the plant cultivator is driven back to the animal tank by a pump. The special feature of the

  12. Voorwoord: Professor Andrzej Borowski

    Directory of Open Access Journals (Sweden)

    Koch Jerzy

    2015-11-01

    Full Text Available Professor Andrzej Borowski from the Jagiellonian University, whose 70th anniversary we celebrate this year, is a very well known scholar and literature historian, specialised in Old Polish Literature (Middle Ages, Renaissance and Baroque - and with a background from Classical studies. A lesser known fact is that he also is a scholar active in the field of the Netherlandish (Dutch and Flemish literature and culture: as author of numerous books and articles about (South Netherlandish figures from the 16th and 17th century, as supervisor of numerous dissertations or habilitations in the field of the Netherlandish literature and as an inspiring personality in the field of the Netherlandish studies at Polish universities. He can indeed be seen as the Spiritus Litterarum Neerlandicorum in Poland.

  13. Using solid13C NMR coupled with solution31P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

    Science.gov (United States)

    Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Wang, Hao; He, Zhongqi; Guo, Wenjing; Song, Fanhao; Giesy, John P

    2017-01-01

    Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid 13 C and solution 31 P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.2% of the total C) were predominant C functional group in the solid 13 C NMR spectra of plant biomass, which may indicate high lability and bioavailability of aquatic plants-derived organic matter in lakes. There was 72.6-103.7% of the total P in aquatic plant biomass extracted by NaOH-EDTA extracts. Solution 31 P NMR analysis of these NaOH-EDTA extracts further identified several molecular species of P including orthophosphate (50.1%), orthophosphate monoesters (46.8%), DNA (1.6%) and pyrophosphate (1.4%). Orthophosphate monoesters included β-glycerophosphate (17.7%), hydrolysis products of RNA (11.7%), α-glycerophosphate (9.2%) and other unknown monoesters (2.1%). Additionally, phytate, the major form of organic P in many lake sediments, was detected in floating plant water poppy. These inorganic P (e.g. orthophosphate and pyrophosphate) and organic P (e.g. diester and its degradation products) identified in plant biomass were all labile and bioavailable P, which would play an important role in recycling of P in lakes. These results increased knowledge of chemical composition and bioavailability of OMs derived from aquatic plants in lakes.

  14. Accumulation of transuranic elements in the aquatic biota of the Belarusian sector of contaminated area near the Chernobyl nuclear power plant - Accumulation of transuranic elements in aquatic biota of Belarusian sector of contaminated area of Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, Alexander; Mironov, Vladislav [International Sakharov Environmental University. Box 220070, 23 Dolgobrodskaya Street, Minsk, 220070 (Belarus)

    2014-07-01

    The evolution of nuclear contamination of Belarus territory after Chernobyl accident includes the four stages: 1. Iodine-neptunium stage, caused mainly by short-lived radionuclides {sup 131}I, {sup 239}Np and others with a half-life period of several weeks; II. Intermediate stage, caused by radionuclides with a half-life period of a year ({sup 144}Ce, {sup 106}Ru, {sup 134}Cs, etc.); III. Strontium-cesium stage, caused by {sup 90}Sr and {sup 137}Cs with a half-life period of about 30 years; IV. Plutonium-americium, caused by long-lived α-emitting radionuclides {sup 241}Am (period of half-life of 432 years) and {sup 239+240}Pu, having high radio and chemo-toxicity. According to forecasts, activity of {sup 241}Am to 2050 year will increase by 2.5 times and it will be the most important dose-related factor for the aquatic biota within the Chernobyl accident zone. In 2002 - 2008 years we have studied the accumulation of trans-uranic elements (TUE, {sup 241}Am, {sup 239+240}Pu) in basic components of water body ecosystems within the Chernobyl zone - non-flowing Perstok Lake, weak-flowing Borschevka flooding and small Braginka River. Among investigated components are water, bottom sediments, submerged macrophytes (Ceratophyllum submersum, Hydrocharis morsus-ranae, Lemna minor, Nuphar lutea, Stratiotes aloides), emergent macrophytes (Typha spp.), shellfish and fish. In the soil cover in the vicinity of the Perstok Lake activity of {sup 241}Am at present is equivalent to 300 - 600 Bq.kg{sup -1}, that is the basic source of its income to the lake. Radionuclides mobility in the water environment is higher than in the soil, that facilitates the rapid incorporation of {sup 241}Am to the trophic nets of water bodies and its removal by near-water animals in the terrestrial biotopes, including outside Chernobyl zone. Thus, the activity of {sup 241}Am in bottom sediments in the Perstok Lake and Borschevka flooding in 2008 year reach respectively 324 and 131 Bq.kg{sup -1}, and the

  15. Aquatic Macrophytes and Their Impact on Water Quality of Lekan ...

    African Journals Online (AJOL)

    Survey of Aquatic Plants of Lekan Aare, South West Nigeria was carried out between May and August 2005. The aquatic ... The Families Cyperaceae and Poaceae topped the list by having 4 species each while the others had 1 species each. ... Key words: Aquatic plants, Lekan Aare Lake, Macrophytes, South West Nigeria.

  16. The first draft genome of the aquatic model plant Lemna minor opens the route for future stress physiology research and biotechnological applications.

    Science.gov (United States)

    Van Hoeck, Arne; Horemans, Nele; Monsieurs, Pieter; Cao, Hieu Xuan; Vandenhove, Hildegarde; Blust, Ronny

    2015-01-01

    Freshwater duckweed, comprising the smallest, fastest growing and simplest macrophytes has various applications in agriculture, phytoremediation and energy production. Lemna minor, the so-called common duckweed, is a model system of these aquatic plants for ecotoxicological bioassays, genetic transformation tools and industrial applications. Given the ecotoxic relevance and high potential for biomass production, whole-genome information of this cosmopolitan duckweed is needed. The 472 Mbp assembly of the L. minor genome (2n = 40; estimated 481 Mbp; 98.1 %) contains 22,382 protein-coding genes and 61.5 % repetitive sequences. The repeat content explains 94.5 % of the genome size difference in comparison with the greater duckweed, Spirodela polyrhiza (2n = 40; 158 Mbp; 19,623 protein-coding genes; and 15.79 % repetitive sequences). Comparison of proteins from other monocot plants, protein ortholog identification, OrthoMCL, suggests 1356 duckweed-specific groups (3367 proteins, 15.0 % total L. minor proteins) and 795 Lemna-specific groups (2897 proteins, 12.9 % total L. minor proteins). Interestingly, proteins involved in biosynthetic processes in response to various stimuli and hydrolase activities are enriched in the Lemna proteome in comparison with the Spirodela proteome. The genome sequence and annotation of L. minor protein-coding genes provide new insights in biological understanding and biomass production applications of Lemna species.

  17. Micro-scale elemental partition in tissues of the aquatic plant Lemna minor L. exposed to highway drainage water

    Energy Technology Data Exchange (ETDEWEB)

    Mendes Godinho, R., E-mail: rmgodinho@yahoo.com [IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, EN 10, 2686-953 Sacavém (Portugal); IPMA Instituto Português do Mar e da Atmosfera, Lisboa 1449-006 (Portugal); Raimundo, J.; Vale, C.; Anes, B.; Brito, P. [IPMA Instituto Português do Mar e da Atmosfera, Lisboa 1449-006 (Portugal); Alves, L.C.; Pinheiro, T. [IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, EN 10, 2686-953 Sacavém (Portugal); CFNUL – Centro de Física Nuclear da Universidade de Lisboa (Portugal)

    2013-07-01

    In the scope of a monitoring program to assess the environmental impact of automobile traffic over one main bridge in Lisbon, both water and duckweed (Lemna minor L.) were sampled from the road drainage tanks and analyzed for chemical elements. Plants uptake Cr, Mn, Cu, and Zn metals from rain water draining the bridge road. Nuclear microprobe elemental maps of cryosections of L. minor tissues showed that incorporated elements were internalized in fronds of the plant. This approach at micrometer level allows a better knowledge of the elemental tissue partitioning in this biomonitor organism.

  18. Aquatic Plant Control Research Program: Proceedings Annual Meeting (28th) Held in Baltimore, Maryland on November 15-18, 1993

    Science.gov (United States)

    1994-06-01

    single cage at Andytown with larvae fauna in Mexico , conducted during October (Table 4). Infested waterlettuce were removed 1993, produced adult and...34 Flow- Scientia Agricultura Sinica 5, 73-76. (in ering plants of the world. V. H. Heywood, Chinese) ed., Mayflower Books, New York. Madsen, J. D. (1993

  19. Scenarios for exposure of aquatic organisms to plant protection products in the Netherlands : part 1: Field crops and downward spraying

    NARCIS (Netherlands)

    Tiktak, A.; Adriaanse, P.I.; Boesten, J.J.T.I.; Griethuysen, van C.; Horst, ter M.M.S.; Linders, J.B.H.J.; Linden, van der A.M.A.; Zande, van de J.C.

    2012-01-01

    In the current Dutch authorisation procedure for calculating the exposure of surface water organisms to plant protection products, drift deposition is considered to be the only source for exposure of surface water organisms. Although drift can still be considered the most important source,

  20. Professor Igor Yevseyev: In Memoriam Professor Igor Yevseyev: In Memoriam

    Science.gov (United States)

    2012-06-01

    Dear readers and authors, June 3, 2012 will mark five months since Professor Igor Yevseyev, Deputy Editor-in-Chief of both journals Laser Physics and Laser Physics Letters passed away, suddenly and unexpectedly. He was 67. Born in Moscow, he entered one of the world's best schools of physics, Moscow Engineering Physics Institute (MEPhI). With this renowned educational and research institution he bonded an alliance for his entire life, starting as an undergraduate student in the Department of Theoretical Physics and later continued as graduate student, assistant professor, associated professor, and full professor in the same department, a rare accomplishment of a person. All those years he retained the love of his life—the love for physics. He worked tirelessly as a teacher and scholar in this captivating field of knowledge. Professor Yevseyev was one of the founders of the international journal of Laser Physics in 1990, the first academic English language journal published in the former USSR. Later, in 2004, the second journal, Laser Physics Letters was brought to the forum of global laser physics community. The idea behind this new title was Professor Yevseyev's initiative to reach the readers and participants with new pioneering and break-through research results more rapidly. His leadership and indefatigable dedication to the quality of published materials made it possible that this journal reached international recognition in a few short years. Still, in order to attract even more attention of potential contributors and readers, Professor Yevseyev originally proposed to conduct the International Laser Physics Workshop (LPHYS) on the annual basis. Since 1992 the Workshop has been conducted every year, each year in a different country. As in all previous years, Professor Yevseyev was the key organizer of this year's workshop in Calgary, Canada. Sadly, this workshop will take place without him. Editorial Board

  1. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Ignacio I.; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M., E-mail: jorgesm@cicy.mx

    2014-10-15

    Highlights: • We document the capacity of an aquatic fern to hyper-accumulate Ni. • Effects of high Ni concentrations uptake on plant performance is documented. • High concentration of Ni in tissues damage photosynthesis. • Damage is related to carboxylation mechanisms than to electron transfer efficiency. • S. minima is a good candidate for remediation of water bodies contaminated with Ni. - Abstract: An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g{sup −1} (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12 h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g{sup −1} internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent.

  2. Assessment of the dye removal capability of submersed aquatic plants in a laboratory-scale wetland system using anova

    Directory of Open Access Journals (Sweden)

    O. Keskinkan

    2007-06-01

    Full Text Available The textile dye (Basic Blue 41(BB41 removal capability of a laboratory-scale wetland system was presented in this study. Twenty glass aquaria were used to establish the wetland. Myriophyllum spicatum and Ceratophyllum demersum were planted in the aquaria and acclimated. After establishing flow conditions, the aquaria were fed with synthetic wastewaters containing BB41. The concentration of the dye was adjusted to 11.0 mg/L in the synthetic wastewater. Hydraulic retention times (HRTs ranged between 3 and 18 days. Effective HRTs were 9 and 18 days. The highest dye removal rates were 94.8 and 94.1% for M. spicatum and C. demersum aquaria respectively. The statistical ANOVA method was used to assess the dye removal capability of the wetland system. In all cases the ANOVA method revealed that plants in the wetland system and HRT were important factors and the wetland system was able to remove the dye from influent wastewater.

  3. Ocorrência de plantas aquáticas nos reservatórios da Light-RJ Ocurrence of aquatic plants in the Light-RJ reservoirs

    Directory of Open Access Journals (Sweden)

    D. Martins

    2003-01-01

    Full Text Available O objetivo do presente trabalho foi caracterizar as comunidades infestantes de plantas aquáticas presentes nos reservatórios da Light-Sistema de Eletricidade S.A., localizada no município de Piraí-RJ. Os levantamentos foram realizados no período de julho a setembro de 1998. Os reservatórios analisados foram: Vigário, Pereira Passos e Lajes, sendo as quantidades de pontos amostrados de 19, 9 e 15, respectivamente. Em cada ponto amostrado fez-se a marcação das coordenadas geográficas e avaliou-se a porcentagem de ocupação do corpo d'água pelas espécies de plantas aquáticas presentes. Depois da identificação das plantas, pôde-se verificar quais eram as espécies mais freqüentes e a sua distribuição dentro do sistema de geração de energia. As espécies encontradas nos reservatórios foram: Brachiaria arrecta (Hack. Stent.; Egeria densa Planch.; Eichhornia azurea (Sw. Kunth.; Eichhornia crassipes (Mart. Solms.; Hymenachne amplexicaulis (Rudge Nees.; Panicum rivulare Trin.; Pistia stratiotis L.; Polygonum spp.; Sagitaria montevidensis Cham. & Schlecht; Salvinia auriculata (Micheli Adans; e Thypha dominguensis L.This study aimed to describe the aquatic weeds infesting the Light-Electric System S.A. reservoirs, located in Pirai-RJ, Brazil. The survey was carried out from July to September 1998. The reservoirs analyzed were: Vigario, Pereira Passos and Lajes, with 19, 9 and 15 points being sampled, respectively. Sampled geographic coordinates were marked in each point and a visual estimate was made of the percentage of river water occupied by the aquatic plants. After plant identification, the most frequent species and their distribution were determined as follows: Brachiaria arrecta (Hack. Stent.; Egeria densa Planch.; Eichhornia azurea (Sw. Kunth.; Eichhornia crassipes (Mart. Solms.; Hymenachne amplexicaulis (Rudge Nees.; Panicum rivulare Trin.; Pistia stratiotis L.; Polygonum spp.; Sagitaria montevidensis Cham.& Schlecht

  4. Aquatic Plant Control Research Program. A Survey of the Continental United States for Pathogens of Eurasian Watermilfoil

    Science.gov (United States)

    1988-04-01

    proven. Hayslip and Zettler (1973) later reported a failure to intro- duce the Northeast River disease in Florida, and Bean , Fusco, and Klarman (1973...Hecht (1981) tested the pathogenicity of Fusarium sporotrichioides to Eurasian water- milfoil. The fungus that was isolated from Eurasian...spicatum L.," Canadian Journal of Plant Science, Vol 59, pp 201-215. Andrews, J. H., and Hecht, E. P. 1981. "Evidence for Pathogenicity of Fusarium

  5. The Profession and the Professors.

    Science.gov (United States)

    Dain, Phyllis

    1980-01-01

    Speculates on why graduate library schools have not, in the persons of their professors, produced theoretical leadership in Library Science. The ideals of professional ethical standards are contrasted with present practice. (RAA)

  6. Response to Professor Jean Guichard

    OpenAIRE

    Kargulowa, Alicja; Czerkawska, Alicja; Kłodkowska, Joanna; Siarkiewicz, Elżbieta; Zielińska-Pękał, Daria; Zierkiewicz, Edyta

    2013-01-01

    The article recounts a discussion inspired by Professor Jean Guichard’s letter to Professor Alicja Kargulowa. Its participants – a group of female counsellogists – are engaged in an e-mail exchange that freely unfolds in the symbolic space of the on-line discourse. Embedded in their own specific research, their contributions depart from a conventional, structured line of argumentation, spontaneously, and at the same time insightfully, reflecting on various facets of purification and translati...

  7. Montsechia, an ancient aquatic angiosperm.

    Science.gov (United States)

    Gomez, Bernard; Daviero-Gomez, Véronique; Coiffard, Clément; Martín-Closas, Carles; Dilcher, David L

    2015-09-01

    The early diversification of angiosperms in diverse ecological niches is poorly understood. Some have proposed an origin in a darkened forest habitat and others an open aquatic or near aquatic habitat. The research presented here centers on Montsechia vidalii, first recovered from lithographic limestone deposits in the Pyrenees of Spain more than 100 y ago. This fossil material has been poorly understood and misinterpreted in the past. Now, based upon the study of more than 1,000 carefully prepared specimens, a detailed analysis of Montsechia is presented. The morphology and anatomy of the plant, including aspects of its reproduction, suggest that Montsechia is sister to Ceratophyllum (whenever cladistic analyses are made with or without a backbone). Montsechia was an aquatic angiosperm living and reproducing below the surface of the water, similar to Ceratophyllum. Montsechia is Barremian in age, raising questions about the very early divergence of the Ceratophyllum clade compared with its position as sister to eudicots in many cladistic analyses. Lower Cretaceous aquatic angiosperms, such as Archaefructus and Montsechia, open the possibility that aquatic plants were locally common at a very early stage of angiosperm evolution and that aquatic habitats may have played a major role in the diversification of some early angiosperm lineages.

  8. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  9. The Detroit River: Effects of contaminants and human activities on aquatic plants and animals and their habitats

    Science.gov (United States)

    Manny, Bruce A.; Kenaga, David

    1991-01-01

    Despite the extensive urbanization of its watershed, the Detroit River still supports diverse fish and wildlife populations. Conflicting uses of the river for waste disposal, water withdrawals, shipping, recreation, and fishing require innovative management. Chemicals added by man to the Detroit River have adversely affected the health and habitats of the river's plants and animals. In 1985, as part of an Upper Great Lakes Connecting Channels Study sponsored by Environment Canada and the U.S. Environmental Protection Agency, researchers exposed healthy bacteria, plankton, benthic macroinvertebrates, fish, and birds to Detroit River sediments and sediment porewater. Negative impacts included genetic mutations in bacteria; death of macroinvertebrates; accumulation of contaminants in insects, clams, fish, and ducks; and tumor formation in fish. Field surveys showed areas of the river bottom that were otherwise suitable for habitation by a variety of plants and animals were contaminated with chlorinated hydrocarbons and heavy metals and occupied only by pollution-tolerant worms. Destruction of shoreline wetlands and disposal of sewage and toxic substances in the Detroit River have reduced habitat and conflict with basic biological processes, including the sustained production of fish and wildlife. Current regulations do not adequately control pollution loadings. However, remedial actions are being formulated by the U.S. and Canada to restore degraded benthic habitats and eliminate discharges of toxic contaminants into the Detroit River.

  10. Numerical modelling of the thermal effects on the aquatic environment from the thermal power plant by using two water discharge pipes

    Science.gov (United States)

    Issakhov, Alibek

    2017-07-01

    The paper presents a numerical modelling of the thermal load on the aquatic environment by using two water discharge pipes of the thermal power plant. It is solved by the Navier-Stokes and temperature transport equations for an incompressible fluid in a stratified medium. The numerical solution of the equation system is divided into four stages by using projection method which was approximated by the finite volume method. At the first step it is assumed that the momentum transfer was carried out only by convection and diffusion. Intermediate velocity field is solved by 5-step Runge-Kutta method. At the second stage, the pressure field is solved by found the intermediate velocity field. Poisson equation for the pressure field is solved by Jacobi method. The third step is assumed that the transfer is carried out only by pressure gradient. The fourth step of the temperature transport equation is also solved as momentum equations. The obtained numerical results of stratified turbulent flow for two water discharged pipes were compared with experimental data and with numerical results for one water discharged pipe. General thermal load in the reservoir-cooler decreases comparing one water discharged pipe and revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler can be seen that from numerical simulations where two water discharged pipes were used.

  11. Impact on the aquatic environment of hydro-peaking in hydroelectric plants; Impact sur le milieu aquatique de la gestion par eclusees des usines hydroelectriques

    Energy Technology Data Exchange (ETDEWEB)

    Sabaton, C.; Lauters, F.; Valentin, S.

    1996-12-31

    There are a number of types of hydroelectric installations on French rivers. Some of these intermittently turbine water stored in dammed reservoirs, in order to use available reserves at the most opportune moment for power generation. These plants, run under `hydro-peaking` management procedures, cause variations in discharge in river sections downstream of the restitution, on a daily or weekly scale. To answer questions concerning the impact of such variations in discharge on the aquatic environment, EDF launched a research program aimed at describing and better understanding the physical and biological phenomena related to hydro-peaking and assessing the possible impact of this type of plant management on French streams. Seven sites subjects to hydro-peaking were studied on rivers with mean flow rates lower than 20 m{sup 3}/s (which corresponds to over 65 % of EDF hydro-peaking sites). Four themes in particular were examined: hydraulic characterization of hydro-peaking, modifications in thermal regime and water quality, response of benthic invertebrates and response of fish populations to hydro-peaking. For fish as well as for invertebrates, the role of the base discharge - in the absence of peaking flow - and that of the morphology of the river bed (and, in particular, the presence of shelter for fish) during periods of strong discharge were clearly highlighted. Impact assessment requires a precise diagnosis of the state of biocenoses. To carry out such a diagnosis, one must reason in terms of species, life phase (particularly the most sensitive phases) and population structure as well as the type of stream and the faunizone involved. A risk assessment is possible by means of simultaneous study of the morphology of the river bed and the response of the signal generated by hydro-peaking in terms of hydrology and physical characteristics downstream of the restitution. (authors). 25 refs.

  12. Cadmium toxicity investigated at the physiological and biophysical levels under environmentally relevant conditions using the aquatic model plant Ceratophyllum demersum

    DEFF Research Database (Denmark)

    Andresen, Elisa; Kappel, Sophie; Stärk, Hans-Joachim

    2016-01-01

    Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under...... environmentally relevant conditions, including nature-like light and temperature cycles, and a low biomass to water ratio. We measured chlorophyll (Chl) fluorescence kinetics, oxygen exchange, the concentrations of reactive oxygen species and pigments, metal binding to proteins, and the accumulation of starch...... and metals. The inhibition threshold concentration for most parameters was 20 nM. Below this concentration, hardly any stress symptoms were observed. The first site of inhibition was photosynthetic light reactions (the maximal quantum yield of photosystem II (PSII) reaction centre measured as Fv /Fm , light...

  13. Phytoextraction of Pb, Cr, Ni, and Zn using the aquatic plant Limnobium laevigatum and its potential use in the treatment of wastewater.

    Science.gov (United States)

    Arán, Daniela Silvina; Harguinteguy, Carlos Alfredo; Fernandez-Cirelli, Alicia; Pignata, María Luisa

    2017-06-21

    In order to study the bioaccumulation of Pb, Cr, Ni, and Zn and the stress response, the floating aquatic plant Limnobium laevigatum was exposed to increasing concentrations of a mixture of these metals for 28 days, and its potential use in the treatment of wastewater was evaluated. The metal concentrations of the treatment 1 (T1) were Pb 1 μg L(-1), Cr 4 μg L(-1), Ni 25 μg L(-1), and Zn 30 μg L(-1); of treatment 2 (T2) were Pb 70 μg L(-1), Cr 70 μg L(-1), Ni 70 μg L(-1), and Zn 70 μg L(-1); and of treatment 3 (T3) were Pb 1000 μg L(-1), Cr 1000 μg L(-1), Ni 500 μg L(-1), and Zn 100 μg L(-1), and there was also a control group (without added metal). The accumulation of Pb, Cr, Ni, and Zn in roots was higher than in leaves of L. laevigatum, and the bioconcentration factor revealed that the concentrations of Ni and Zn in the leaf and root exceeded by over a thousand times the concentrations of those in the culture medium (2000 in leaf and 6800 in root for Ni; 3300 in leaf and 11,500 in root for Zn). Thus, this species can be considered as a hyperaccumulator of these metals. In general, the changes observed in the morphological and physiological parameters and the formation of products of lipid peroxidation of membranes during the exposure to moderate concentrations (T2) of the mixture of metals did not cause harmful effects to the survival of the species within the first 14 days of exposure. Taking into account the accumulation capacity and tolerance to heavy metals, L. laevigatum is suitable for phytoremediation in aquatic environments contaminated with moderated concentrations of Cr, Ni, Pb, and Zn in the early stages of exposure.

  14. Lake nutrient variability inferred from elemental (C, N, S) and isotopic (δ 13C, δ 15N) analyses of aquatic plant macrofossils

    Science.gov (United States)

    Herzschuh, Ulrike; Mischke, Steffen; Meyer, Hanno; Plessen, Birgit; Zhang, Chengjun

    2010-08-01

    This paper aims to highlight the potential of using elemental and stable isotope analyses of aquatic macrophytes in palaeolimnological studies. Potamogeton pectinatus material was collected from modern plants ( n = 68) and from late glacial and Holocene-aged sediments from Koucha Lake (northeastern Tibetan Plateau; 34.0°N; 97.2°E; 4540 m a.s.l.). It was analyzed for δ 13C Potamogeton (modern: -23 to 0‰, fossil: -19 to -4‰) and δ 15N Potamogeton (modern: -11.0 to +13.8‰, fossil: -9.5 to +6.7‰) in addition to elemental carbon and nitrogen (modern C/N Potamogeton: 7 to 29; fossil: 13 to 68) and sulfur (fossil: 188-899 μmol/g dry weight). Fossil data were interpreted in terms of palaeo-nutrient availability and palaeo-productivity based on the modern relationships between various proxies and certain environmental data. Productivity of Potamogeton pectinatus mats at Koucha Lake as indicated by palaeo-ɛ Potamogeton-TIC (i.e. the enrichment of δ 13C Potamogeton relative to the δ 13C TIC) was reduced during periods of high conductivity, especially between 10.3 and 7.4 cal kyr BP. Potamogeton pectinatus material from these periods was also characterized by high S Potamogeton indicating high sulfide concentrations and anoxic conditions within the sediments. However, C/N Potamogeton ratios and δ 15N Potamogeton from the lower core section were found to have been altered by decompositional processes. A pronounced shift in the aquatic productivity of Lake Koucha occurred at ˜7.4 cal kyr BP when the hydrological conditions shifted towards an open lake system and water depth increased. At this time a strong increase in productivity led to a strong decrease in the water HCO 3- concentration as inferred from the application of a ɛ Potamogeton-TIC-lnHCO 3- transfer function. A comparison of reconstructed productivity changes from Koucha Lake with further environmental proxies suggests that primary productivity changes are probably a function of internal lake

  15. Differences in mechanical and structural properties of surface and aerial petioles of the aquatic plant Nymphaea odorata subsp. tuberosa (Nymphaeaceae).

    Science.gov (United States)

    Etnier, Shelley A; Villani, Philip J

    2007-07-01

    Lily pads (Nymphaea odorata) exhibit heterophylly where a single plant may have leaves that are submerged, floating, or above (aerial) the surface of the water. Lily pads are placed in a unique situation because each leaf form is exposed to a distinctly different set of mechanical demands. While surface petioles may be loaded in tension under conditions of wind or waves, aerial petioles are loaded in compression because they must support the weight of the lamina. Using standard techniques, we compared the mechanical and morphological properties of both surface and aerial leaf petioles. Structural stiffness (EI) and the second moment of area (I) were higher in aerial petioles, although we detected no differences in other mechanical values (elastic modulus [E], extension ratio, and breaking strength). Morphologically, aerial petioles had a thicker rind, with increased collenchyma tissue and sclereid cell frequency. Aerial petioles also had a larger cross-sectional area and were more elliptical. Thus, subtle changes in the distribution of materials, rather than differences in their makeup, differentiate petiole forms. We suggest that the growth of aerial petioles may be an adaptive response to shading, allowing aerial leaves to rise above a crowded water surface.

  16. Sunlight photo-assisted TiO₂-based pilot plant scale remediation of (simulated) contaminated aquatic sites.

    Science.gov (United States)

    Oyama, Toshiyuki; Takeuchi, Masashi; Yanagisawa, Ippei; Koike, Takayoshi; Serpone, Nick; Hidaka, Hisao

    2010-01-01

    A tubular-type solar photoreactor system powered by commercial solar panels and consisting of six 20-tube modules (Pyrex glass) to mimic a pilot plant scale configuration was designed and constructed to examine the remediation of simulated wastewaters contaminated with various classes of organic pollutants such as endocrine disruptors (e.g. bisphenol A), anionic surfactants (sodium butylnaphthalenesulfonate and sodium dodecyl- benzenesulfonate), herbicides (e.g. 2,4-dichlorophenoxyacetic acid) and a commercial dishwasher detergent. Photo-oxidative processes followed first-order kinetics expressed in terms of the total light energy (in kJ) that impinged on the photoreactor. The influence of TiO₂ loading and circulation flow rate of the wastewaters on the dynamics of the photo-oxidation to mineralization (loss of total organic carbon, TOC, or formation of sulfate ions) was investigated. The optimal operational parameters were: TiO₂ loading, 2 g L⁻¹; circulation flow rate, 7.5 L min⁻¹. On a sunny day, near- quantitative mineralization of the contaminants was achieved after only 4 h of irradiation that corresponded to an accumulated energy of ca 1380 kJ.

  17. Silver nanoparticles induced accumulation of reactive oxygen species and alteration of antioxidant systems in the aquatic plant Spirodela polyrhiza.

    Science.gov (United States)

    Jiang, Hong-Sheng; Qiu, Xiao-Ni; Li, Gen-Bao; Li, Wei; Yin, Li-Yan

    2014-06-01

    Silver nanoparticles (AgNPs) are widely used commercially because of their antibacterial properties. Oxidative stress is known to be involved in the toxicity of AgNPs to bacteria, animals, and algae. The authors used Spirodela polyrhiza to investigate whether AgNPs can induce oxidative stress in higher plants. Results showed that there was a dose-dependent increase in levels of reactive oxygen species, superoxide dismutase and peroxidase activity, and the antioxidant glutathione content in 6-nm AgNP treatments. Catalase activity and malondialdehyde content in 6-nm AgNP treatments was significantly higher than the control at silver concentrations of 5 mg L(-1) . Superoxide dismutase and catalase activity and antioxidant glutathione and malondialdehyde content were not significantly different at 10 mg L(-1) of AgNPs (6 nm and 20 nm). Treatment with 20 µg L(-1) Ag(+) (the amount almost equal to 10 mg L(-1) AgNPs released) did not change the reactive oxygen species level or antioxidant enzymes activity. Micron-sized Ag particles had no effect on S. polyrhiza. Transmission electron microscopy showed that, compared with the control, chloroplasts in S. polyrhiza treated with 6-nm and 20-nm AgNPs accumulated starch grains and had reduced intergranal thylakoids. These results clearly indicate that AgNPs are able to cause oxidative stress and affect the chloroplast structure and function of S. polyrhiza, and this effect was not caused by Ag(+) released from particles. © 2014 SETAC.

  18. Checklist of the Aquatic Macrophytes

    African Journals Online (AJOL)

    aquatic plants colonize the fresh water bodies in. Nigeria with Jebba Lake as a case study. Nigerian water bodies are of high economic importance to the riparian populace and other stakeholders that depend on such water bodies for their economic activities. It is therefore essential to monitor and manage the influx of these ...

  19. Il professor Mitja Skubic ottuagenario

    Directory of Open Access Journals (Sweden)

    Martina Ožbot

    2008-12-01

    Full Text Available Incredibile ma vero: il professor Mitja Skubic si trova, questa volta lui stesso, al centro dell’attenzione anziché essere il motore, il perno dell’attività. La ragione per questo attimo di respiro è il suo ottantesimo compleanno, a dire il vero passato già da tempo. È pressoché una contingenza aneddotica quella per cui il volume dedicatogli per l’occasione viene pubblicato così tardi: il professore ha continuato a tener d’occhio la nostra rivista ben dopo aver nominato i nuovi direttori tanto che sarebbe stato impossibile sorprenderlo con una miscellanea di contributi in suo onore.

  20. Professor@s e Eros Teachers and Eros

    Directory of Open Access Journals (Sweden)

    Deborah P. Britzman

    2009-01-01

    Full Text Available Professores/as são testemunhas do fantástico mundo da sexualidade. Esse artigo explora a centralidade de Eros para a educação e estabelece uma relação entre o desejo do/a professor/a e os acontecimentos emocionais da relação própria relação aluno/professor. Eu proponho que o aprendizado deva envolver nosso "eu" erótico, além das nossas fantasias. Mas esta perspectiva requer que professores/as considerem uma psicologia do amor como um caminho principal para a as situações emocionais de Eros. Na sua conclusão este trabalho sugere uma pedagogia que dê as boas vindas tanto à homossexualidade como a heterossexualidade como expressões humanas do amor.Teachers bear witness to the wondrous world of sexuality. This essay explores the centrality of Eros to education and links the teacher's desire to the emotional situation of the student/teacher relationship. I propose that learning involves our erotic selves and our fantasy life. But such a view requires that teachers consider a psychology of love as lending insight into the emotional situation of Eros. The paper concludes by suggesting a pedagogy that welcomes homosexuality and heterosexuality as human expressions of love.

  1. Deficiency and toxicity of nanomolar copper in low irradiance—A physiological and metalloproteomic study in the aquatic plant Ceratophyllum demersum

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, George [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Andresen, Elisa [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Institute of Plant Molecular Biology, Department Plant Biophysics and Biochemistry, Biology Centre of the ASCR, Branišovská 31/1160, CZ-37005 České Budějovice (Czech Republic); Mattusch, Jürgen [UFZ − Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, D-04318 Leipzig (Germany); Hubáček, Tomáš [Institute of Hydrobiology, Department of Hydrochemistry and Ecosystem Modelling, Biology Centre of the ASCR, Na Sádkách 7, 37005 České Budějovice (Czech Republic); SoWa National Research Infrastructure, Biology Centre of the ASCR, Na Sádkách 7, 37005 České Budějovice (Czech Republic); and others

    2016-08-15

    Highlights: • Environmentally relevant toxicity and limitation of Cu were investigated. • Copper > 50nM replaces Mg in the LHCII‐trimers. • Deficiency causes decreased electron flow through PSII via lack of plastocyanin. • Of all metabolic pathways, photosynthesis was most affected by Cu toxicity. • Detection of Cu in the Chl peaks of LHCII suggests the generation of [Cu]‐Chl. - Abstract: Essential trace elements (Cu{sup 2+}, Zn{sup 2+}, etc) lead to toxic effects above a certain threshold, which is a major environmental problem in many areas of the world. Here, environmentally relevant sub-micromolar concentrations of Cu{sup 2+} and simulations of natural light and temperature cycles were applied to the aquatic macrophyte Ceratophyllum demersum a s a model for plant shoots. In this low irradiance study resembling non‐summer conditions, growth was optimal in the range 7.5–35 nM Cu, while PSII activity (F{sub v}/F{sub m}) was maximal around 7.5 nM Cu. Damage to the light harvesting complex of photosystem II (LHCII) was the first target of Cu toxicity (>50 nM Cu) where Cu replaced Mg in the LHCII-trimers. This was associated with a subsequent decrease of Chl a as well as heat dissipation (NPQ). The growth rate was decreased from the first week of Cu deficiency. Plastocyanin malfunction due to the lack of Cu that is needed for its active centre was the likely cause of diminished electron flow through PSII (Φ{sub PSII}). The pigment decrease added to the damage in the photosynthetic light reactions. These mechanisms ultimately resulted in decrease of starch and oxygen production.

  2. Photodegradation of gaseous acetaldehyde and methylene blue in aqueous solution with titanium dioxide-loaded activated carbon fiber polymer materials and aquatic plant ecotoxicity tests.

    Science.gov (United States)

    Kadirova, Zukhra C; Hojamberdiev, Mirabbos; Katsumata, Ken-ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

    2014-03-01

    TiO2-supported activated carbon felts (TiO2-ACFTs) were prepared by dip coating of felts composed of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) and/or a polyethylene pulp (PE-W15) in a TiO2 aqueous suspension followed by calcination at 250 °C for 1 h. The as-prepared TiO2-ACFTs with 29-35 wt.% TiO2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption. The TiO2-ACFT(PS-A20) samples with 0 and 29 wt.% TiO2 were microporous with specific surface areas (S BET) of 996 and 738 m(2)/g, respectively, whereas the TiO2-ACFT(PE-W15) samples with 0 and 35 wt.% TiO2 were mesoporous with S BET of 826 and 586 m(2)/g, respectively. Adsorption and photocatalytic activity of the as-prepared samples were evaluated by measuring adsorption in the dark and photodegradation of gaseous acetaldehyde (AcH) and methylene blue (MB) in aqueous solution under UV light. The TiO2 loading caused a considerable decrease in the S BET and MB adsorption capacity along with an increase in MB photodegradation and AcH mineralization. Lemna minor was chosen as a representative aquatic plant for ecotoxicity tests measuring detoxification of water obtained from the MB photodegradation reaction with the TiO2-ACFT samples under UV light.

  3. Professors of the New Economy.

    Science.gov (United States)

    Wilson, Robin

    2000-01-01

    Profiles four professors who epitomize the increasing influence of academe on new technology-driven Internet business: a start-up maven, Steven Kaplan; a social psychologist, Michael Ray; a cyberlawyer, David Post; and an e-commerce expert, Andrew B. Whinston. (DB)

  4. Effect of major cations (Ca2+, Mg2+, Na+, K+) and anions (SO4(2-), Cl- , NO3-) on Ni accumulation and toxicity in aquatic plant (Lemna minor L.): implications For Ni risk assessment.

    Science.gov (United States)

    Gopalapillai, Yamini; Hale, Beverley; Vigneault, Bernard

    2013-04-01

    The effect of major cation activity (Ca(2+) , Mg(2+) , Na(+) , K(+) ) on Ni toxicity, with dose expressed as exposure (total dissolved Ni concentration NiTot ) or free Ni ion activity (in solution Ni(2+) ), or as tissue residue (Ni concentration in plant tissue NiTiss ) to the aquatic plant Lemna minor L. was examined. In addition, Ni accumulation kinetics was explored to provide mechanistic insight into current approaches of toxicity modeling, such as the tissue residue approach and the biotic ligand model (BLM), and the implications for plant Ni risk assessment. Major cations did not inhibit Ni accumulation via competitive inhibition as expected by the BLM framework. For example, Ca(2+) and Mg(2+) (sulfate as counter-anion) had an anticompetitive effect on Ni accumulation, suggesting that Ca or Mg forms a ternary complex with Ni-biotic ligand. The counter-anion of the added Ca (sulfate, chloride, or nitrate) affected plant response (percentage of root growth inhibition) to Ni. Generally, sulfate and chloride influenced plant response while nitrate did not, even when compared within the same range of Ca(2+) , which suggests that the anion dominated the observed plant response. Overall, although an effect of major cations on Ni toxicity to L. minor L. was observed at a physiological level, Ni(2+) or NiTot alone modeled plant response, generally within a span of twofold, over a wide range of water chemistry. Thus, consideration of major cation competition for improving Ni toxicity predictions in risk assessment for aquatic plants may not be necessary. Copyright © 2013 SETAC.

  5. NOTES ON CONTRIBUTORS H. Johnson Nenty, Professor ...

    African Journals Online (AJOL)

    Admin

    NOTES ON CONTRIBUTORS. H. Johnson Nenty, Professor, Educational Research, Measurement and Evaluation, Department of Educational. Foundations, University of Botswana Idowu Biao, Professor of Lifelong learning, Department of Adult Education,. University of Botswana. Cletus K. Mbowura, Lecturer, Department of ...

  6. Saponins in the aquatic environment

    DEFF Research Database (Denmark)

    Jiang, Xiaogang

    extract) in the environment, and to relate the measurements to the potential risk of the different fractions (saponins and non-saponins) in the saponin-rich plant extract. The toxicity tests were conducted with the aquatic crustacean Daphnia magna and zebrafish (Danio rerio) embryos. We confirm......This PhD thesis consists of three parts to illustrate the goal of getting a better understanding of the fate and toxicity of saponins in the aquatic environment. It includes an introduction to the general aspects of saponins, their chemistry and the ecotoxicology concepts, and a second part......-like structure, saponins have a lot of applications, e.g. as foaming agents in consumer products, as adjuvants in the vaccine, as biosurfactants in soil washing and as biopesticides in crop protection. Hence, they may leach into the aquatic environment due to their low octanol/water partition coefficient...

  7. ICT Use by Journalism Professors in Colombia

    Science.gov (United States)

    Hung, Elias Said

    2011-01-01

    This article analyses how journalism professors at Colombian universities use information and communications technologies (ICT) in their teaching. Survey data was obtained during the first trimester of 2009 from 63 professors in journalism departments and from a total of 865 professors who are affiliated with journalism departments at 29…

  8. Erratum: Professor J. H. S. Gear

    African Journals Online (AJOL)

    s short of their. Lesley, a nd their amily a proper Wake on 15 November 1994. Erratum: Professor J. H. S. Gear. The name of Professor B. D. Schoub, Director of the. National Institute for Virology, was inadvertently omitted as the author of the obituary of Professor J. H. S. Gear published in the September 1994 SAMJ. Books.

  9. Aquatic arsenic: phytoremediation using floating macrophytes.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-04-01

    Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumulating plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    Science.gov (United States)

    1989-10-01

    thesis, Botany Dept., Univ. Calif. [Alleopathy, Eleocharis, Phytotoxicity] Westlake, D. F. 1982. "Ecology-community metabolism and production: The primary...be growth stimulatory while I. aquatica is growth inhibitory. They suggest that the growth-promoting effect may be due to terpenoids and that the

  11. Species specificity of resistance to oxygen diffusion in thin cuticular membranes from amphibious plants

    DEFF Research Database (Denmark)

    Frost-Christensen, Henning; Jørgensen, Lise Bolt; Floto, Franz

    2003-01-01

    oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants......oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants...

  12. Surveillance of terrestrial and aquatic environment of the Chinon nuclear power plant. Year 2002-2003; Surveillance de l'environnement terrestre et aquatique de la centrale de Chinon. Annee 2002-2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    We find dosage of gamma emitters radionuclides of samples collected in the environment of the Chinon nuclear power plant for 2002 and 2003, these results are presented in two tables: concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils) and aquatic environment (sediments) of the site of Chinon in june 2002 in the frame of the annual surveillance, the second table concerns the concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils and lichens) of the site of Chinon in may 2003 in the frame of the annual surveillance. We find also the dosage of free tritium in the water of the Loire river for 2002 and 2003, upstream and downstream to the power plant of Chinon. (N.C.)

  13. Aquatic Therapy for Children

    Science.gov (United States)

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  14. Interview with Professor Mark Wilcox.

    Science.gov (United States)

    Wilcox, Mark

    2016-08-01

    Mark Wilcox speaks to Georgia Patey, Commissioning Editor: Professor Mark Wilcox is a Consultant Microbiologist and Head of Microbiology at the Leeds Teaching Hospitals (Leeds, UK), the Professor of Medical Microbiology at the University of Leeds (Leeds, UK), and is the Lead on Clostridium difficile and the Head of the UK C. difficile Reference Laboratory for Public Health England (PHE). He was the Director of Infection Prevention (4 years), Infection Control Doctor (8 years) and Clinical Director of Pathology (6 years) at the Leeds Teaching Hospitals. He is Chair of PHE's Rapid Review Panel (reviews utility of infection prevention and control products for National Health Service), Deputy Chair of the UK Department of Health's Antimicrobial Resistance and Healthcare Associated Infection Committee and a member of PHE's HCAI/AR Programme Board. He is a member of UK/European/US working groups on C. difficile infection. He has provided clinical advice as part of the FDA/EMA submissions for the approval of multiple novel antimicrobial agents. He heads a healthcare-associated infection research team at University of Leeds, comprising approximately 30 doctors, scientists and nurses; projects include multiple aspects of C. difficile infection, diagnostics, antimicrobial resistance and the clinical development of new antimicrobial agents. He has authored more than 400 publications, and is the coeditor of Antimicrobial Chemotherapy (5th/6th/7th Editions, 15 December 2007).

  15. The Forgetful Professor and the Space Biology Adventure

    Science.gov (United States)

    Massa, Gioia D.; Jones, Wanda; Munoz, Angela; Santora, Joshua

    2014-01-01

    This video was created as one of the products of the 2013 ISS Faculty Fellows Summer Program. Our High School science teacher faculty fellows developed this video as an elementary/middle school education component. The video shows a forgetful professor who is trying to remember something, and along the journey she learns more about the space station, space station related plant science, and the Kennedy Space Center. She learns about the Veggie hardware, LED lighting for plant growth, the rotating garden concept, and generally about space exploration and the space station. Lastly she learns about the space shuttle Atlantis.

  16. Resource Assessment for Microalgal/Emergent Aquatic Biomass Systems in the Arid Southwest: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Vigon, B. W.; Arthur, M. F.; Taft, L. G.; Wagner, C. K.; Lipinsky, E. S.; Litchfield, J. H.; McCandlish, C. D.; Clark, R.

    1982-12-23

    This research project has been designed to facilitate the eventual selection of biomass production systems using aquatic species (microalgal and emergent aquatic plant species (MEAP) which effectively exploit the potentially available resources of the Southwest.

  17. Professor Gender, Age, and "Hotness" in Influencing College Students' Generation and Interpretation of Professor Ratings

    Science.gov (United States)

    Sohr-Preston, Sara L.; Boswell, Stefanie S.; McCaleb, Kayla; Robertson, Deanna

    2016-01-01

    A sample of 230 undergraduate psychology students rated their expectations of a bogus professor (who was randomly designated a man or woman and "hot" versus "not hot") based on ratings and comments found on RateMyProfessors.com. Five professor qualities were derived using principal components analysis: dedication,…

  18. 'Supermentoring' of assistant professors' teaching

    DEFF Research Database (Denmark)

    Lauridsen, Ole

    Aarhus University offers a mandatory pedagogical training program for assistant professors, required in order to obtain tenure at a Danish university. At Business and Social Sciences, this program is supplemented by voluntary observation and (first of all formative) supervision of the assistant...... professors’ teaching practice. This offer is given is (i) because many young university teachers face problems putting pedagogical theory into practice – even though the program mentioned is practice-oriented, and (ii) because many of them (partly due to (i)) lack self-confidence as to teaching....... The presentation will discuss the theoretical framework of the supervision given and compare it to other supervision models. Furthermore it will address the need of working with supervision in a SOTL context. Attendees will be activated through discussion of short prototypical cases. A possible – and desired...

  19. Observations on Professor Hayek's Plan

    Directory of Open Access Journals (Sweden)

    Ludwig von Mises

    2009-01-01

    Full Text Available This memorandum was written at the request of Henry Hazlitt to provide Mises’s comments on and concerns about F.A. Hayek’s initial proposals for what became the Mont Pèlerin Society. Mises stresses that those who favor liberty and freedom and oppose totalitarianism must also oppose interventionism. The memo argues that those who fought and lost against the rising tide of totalitarianism at the turn of the 20th Century lost their battles because they settled for middle-of-the-road policies that conceded considerable ground to the socialists. The weak point in Professor Hayek’s plan is that it relies upon the cooperation of many men who are today’s middle-of-the-roaders. As interventionists, they may not be the hoped-for intellectual pioneers to inspire people to build a freer world.

  20. Professor Camillo Negro's Neuropathological Films.

    Science.gov (United States)

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease.

  1. How College Students View a Professor's Role

    Science.gov (United States)

    Gadzella, Bernadette M.

    1977-01-01

    Views of 3,670 students from six colleges and universities on most and least important traits of an ideal professor were analyzed. All data were collected with the same instrument. Data revealed students selected similar MOST and LEAST important traits of a quality professor. (Author)

  2. Finnish Students' Perceptions of a Visiting Professor.

    Science.gov (United States)

    Haussler, Susan C.; Paavilainen, Eija; Astedt-Kurki, Paivi

    2003-01-01

    Finnish nursing students (n=31) evaluated their experience with a visiting Fulbright professor. Students were satisfied with course content, teaching methods, and information about the U.S. health care system. They thought the professor should have been more knowledgeable about Finnish culture, education, and health care. (Contains 15 references.)…

  3. Professor Delight: Cultivating Organizational Citizenship Behavior

    Science.gov (United States)

    Mazen, Abdelmagid; Herman, Susan; Ornstein, Suzyn

    2008-01-01

    This article describes the rationale for and use of a class innovation the authors call "professor delight." This inexpensive, high-yield concept allows students and professors to enact their understanding of citizenship throughout the term, and often beyond. The authors explain the concept, describe its implementation in class, and link it to the…

  4. Memorial to Professor Antonio Barone

    Science.gov (United States)

    Tafuri, Francesco; Pepe, Giampiero; Vaglio, Ruggero

    2014-04-01

    Antonio Barone prematurely passed away on 4 December 2011 at the age of 72, after a one-year battle with cancer. He left behind his wife Sveva and his two sons, Alberto and Livio. Antonio was Professor Emeritus at the University of Napoli Federico II, where he had been teaching for about 40 years. The initial research activity of Antonio was in the field of nuclear physics. In this context, almost 45 years ago, the Ge 'Lithium drift' semiconductor detectors represented a novelty, due to the high energy resolution enabled by those devices. Superconductors stimulated new approaches to radiation detection and this motivated Antonio's interest towards superconductivity. Following the birth of the Laboratorio di Cibernetica of the CNR in 1967 he was given the opportunity to work on a joint USA-Italy project (University of Wisconsin, Madison and CNR Naples) in the field of superconductivity on the peculiar subject of the superconductive 'Neuristors'. His research activity on Josephson junctions opened up a wide variety of very stimulating subjects in which he was deeply involved, ranging from the soliton propagation in 'long' Josephson structures to fluctuations phenomena, from light-sensitive junctions and proximity effect to the development of innovative superconducting devices. The strong interaction of Antonio with the Landau Institute for Theoretical Physics of the Academy of Sciences in Moscow, characterizes a long period of his research activity with a precious merging of theoretical and experimental aspects. This body of work converged into the famous monograph on the 'Physics and Applications of the Josephson Effect', written in collaboration with Gianfranco Paternò in 1982. This rapidly became the reference text for the Josephson effect, as documented by thousands of citations and the fact that it was translated into Russian, Japanese and Chinese. In 1983 Antonio was awarded the highest academic title of 'Doctor of the Physical-Mathematical Sciences' by the

  5. Desenvolvimento de equipamento para controle mecânico de plantas aquáticas na UHE de Americana-SP Development of equipment for mechanical control of aquatic plants at the Americana reservoir in Brazil

    Directory of Open Access Journals (Sweden)

    L.F.N. Bravin

    2005-06-01

    Full Text Available Os objetivos deste trabalho foram desenvolver e avaliar o rendimento operacional de um equipamento para controle de plantas aquáticas, além de estabelecer procedimentos que permitissem a otimização dessa prática na UHE de Americana-SP. O equipamento constitui-se de uma esteira de margem (3,0 m de largura x 10,0 m de comprimento para captação e condução das plantas até um picador, que as fragmenta antes do descarte, facilitando assim sua decomposição e seu transporte. A análise realizada indicou que a capacidade operacional foi de aproximadamente 7,73 m³ h-1. Considerando-se a menor taxa de crescimento observada no histórico do reservatório, 2,27%, o sistema deveria permitir a remoção de aproximadamente 28 m³ h-1. Dessa forma, esse equipamento pode funcionar como um método auxiliar no controle das plantas aquáticas, não realizando um controle efetivo se empregado de forma isolada.The aim of this work was to develop and evaluate the operational capacity of a device for aquatic plant control, as well to establish procedures to improve plant control at the Americana reservoir in Brazil. Basically, the equipment consists of a shore conveyor (3.0 m wide x 10.0 m long for collecting and carrying the plants to a cutter (that breaks the plants before transportation, facilitating their decomposition and transport. The analysis showed that the operational capacity of the equipment was approximately 7.73 m³ h-1. Considering the lowest growth index observed in the reservoir description, 2.27%, the system should remove approximately 28 m³ h-1. This equipment can act as a support for aquatic plant control, without providing an effective control when used alone.

  6. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  7. Cation-induced coagulation of aquatic plant-derived dissolved organic matter: Investigation by EEM-PARAFAC and FT-IR spectroscopy

    Science.gov (United States)

    Interaction and coagulation of plant-derived dissolved organic matter (DOM) by metal cations are important biogeochemical processes of organic matter in lake systems. Thus, coagulation and fractionation of plant-derived DOM by di- and tri-valent Ca, Al, and Fe ions were investigated. Metal ion-induc...

  8. PROFESSORES: IMAGENS DO FUTURO PRESENTE

    Directory of Open Access Journals (Sweden)

    Maitê Alves Bezerra

    2014-06-01

    Full Text Available Ao observar a comunidade portuguesa que busca compreender a historicidade das formas e dos processos de escolarização por meio do estabelecimento de intenso diálogo com outras comunidades, é impossível não dar destaque à figura de António Manuel Seixas Nóvoa. Nascido em Lisboa no ano de 1954, aos 18 anos inicia o curso de Ciências da Educação na Universidade de Lisboa. Após lecionar em importantes universidades tais como Paris V, Oxford e Columbia University, atualmente acumula as posições de reitor da Universidade de Lisboa e professor catedrático da Faculdade de Psicologia e de Ciências da Educação na Instituição. Nóvoa tem se destacado à frente de debates internacionais a respeito da história da educação e educação comparada.

  9. Concentrations of heavy metals and plant nutrients in water, sediments and aquatic macrophytes of anthropogenic lakes (former open cut brown coal mines) differing in stage of acidification

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A. [Department of Ecology and Nature Protection, Wroclaw University, ul. Kanonia 6/8, 50-328 Wroclaw (Poland); Kempers, A.J. [Department of Biogeology, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen (Netherlands)

    2001-12-17

    Concentration of heavy metals (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) as well as macronutrients (N, P, K, Ca, Mg, S) were measured in water, bottom sediments and plants from anthropogenic lakes in West Poland. The collected plants were: Phragmites australis, Potamogeton natans, Iris pseudoacorus, Juncus effusus, Drepanocladus aduncus, Juncus bulbosus, Phalaris arundinacea, Carex remota and Calamagrostis epigeios. Two reference lakes were sampled for Nymphaea alba, Phragmites australis, Schoenoplectus lacustris, Typha angustifolia and Polygonum hydropiper. These plants contained elevated levels of Cd, Co, Cr, Cu and Mn, and part of the plants contained in addition elevated levels of Mn, Fe, Pb, Ni and Zn. Analyses of water indicated pollution with sulfates, Cd, Co, Ni, Zn, Pb and Cu, and bottom sediments indicated that some of the examined lakes were polluted with Cd, Co and Cr. Strong positive correlations were found between concentrations of Co in water and in plants and between Zn in sediments and plants, indicating the potential of plants for pollution monitoring for this metal. Heavy metal accumulation seemed to be directly associated with the exclusion of Ca and Mg.

  10. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  11. Professor Haeckel in Ceylon 1

    National Research Council Canada - National Science Library

    1882-01-01

    IV. PROF. HAECKEL, in describing his first impression of Galle, does not fail to mention as one of its principal features the long lines of shady Suriya trees and flowering Hibiscus, planted by the Dutch...

  12. Optimization of methodology by X-ray fluorescence for the metals determination in aquatic plants of the high course of the Lerma river; Optimizacion de la metodologia por fluorescencia de rayos X para la determinacion de metales en plantas acuaticas del curso alto del Rio Lerma

    Energy Technology Data Exchange (ETDEWEB)

    Albino P, E.

    2015-07-01

    The high course of the Lerma river has a pollution problem in its hydrological system due to discharges of urban wastewater and industrial areas; the pollutants that affect the hydrological system are metals, which are absorbed by living organisms and probably incorporated into the food chain. For this reason in this work the technique of X-ray fluorescence total reflection was applied in six species of aquatic plants that grow in the high course of the Lerma river: Arroyo Mezapa (Eichhornia crassipes, Juncus efusus, Hydrocotyle, Schoenoplectus validus) Ameyalco river (Lemna gibba) and Atarasquillo river (Berula erecta) in order to evaluate the metals concentration (Cr, Mn, Fe, Ni, Cu, Zn and Pb) as well as the translocation factor and bioaccumulation factor for each aquatic species. According to the results, was observed that the highest concentration of metals is located in the deeper parts; metals which present a significant concentration are Mn and Fe in the six species of aquatic plants. According to the translocation factor the species having a higher translocation of metals are: Juncus efusus in Mn (1.19 mg/L) and Zn (1.31 mg/L), Hydrocotyle (1.14 mg/L), the species Eichhornia crassipes not show translocation. For bioaccumulation factor, was observed that the most bioaccumulation of metals is found in the soluble fraction of the six species of aquatic plants, especially Fe followed of Cu and Zn. Also was considered that the Berula erecta plant had a higher bioaccumulation of metals such as Cr, Mn, Fe, Cu and Zn so it can be considered as a hyper-accumulating species of these elements. With the results can be considered that the technique of X-ray fluorescence total reflection is 95% reliable to determine the concentration of metals within the structures of the aquatic plants used for this study. (Author)

  13. Automatic non-destructive three-dimensional acoustic coring system for in situ detection of aquatic plant root under the water bottom

    Directory of Open Access Journals (Sweden)

    Katsunori Mizuno

    2016-05-01

    Full Text Available Digging is necessary to detect plant roots under the water bottom. However, such detection is affected by the transparency of water and the working skills of divers, usually requires considerable time for high-resolution sampling, and always damages the survey site. We developed a new automatic non-destructive acoustic measurement system that visualizes the space under the water bottom, and tested the system in the in situ detection of natural plant roots. The system mainly comprises a two-dimensional waterproof stage controlling unit and acoustic measurement unit. The stage unit was electrically controlled through a notebook personal computer, and the space under the water bottom was scanned in a two-dimensional plane with the stage unit moving in steps of 0.01 m (±0.0001 m. We confirmed a natural plant root with diameter of 0.025–0.030 m in the reconstructed three-dimensional acoustic image. The plant root was at a depth of about 0.54 m and the propagation speed of the wave between the bottom surface and plant root was estimated to be 1574 m/s. This measurement system for plant root detection will be useful for the non-destructive assessment of the status of the space under the water bottom.

  14. Professor dr hab. Anna Maria Bujakiewicz

    Directory of Open Access Journals (Sweden)

    Anna Kujawa

    2015-08-01

    Full Text Available The article presents the biography and scientific achievements of Professor Anna Bujakiewicz. After receiving her master’s degree and doctorate in biology and mycology from Adam Mickiewicz University in Poznań, Professor Bujakiewicz continued her exciting research and teaching on mycology at her Alma Mater Posnaniensis for more than 50 years. Her publications in this field include many books, articles, and other scholarly reports.

  15. Levantamento da infestação de plantas aquáticas em Porto Primavera antes do enchimento final do reservatório Aquatic plant infestation assessment in Porto Primavera reservoir before final filling

    Directory of Open Access Journals (Sweden)

    D Martins

    2009-12-01

    Full Text Available O objetivo deste trabalho foi identificar as plantas aquáticas e os níveis de infestação de cada espécie em Porto Primavera antes do enchimento final do reservatório. Foram avaliados todos os focos de vegetação aquática no reservatório (72 pontos, sendo os pontos demarcados com um aparelho de GPS. As espécies foram identificadas e estimouse visualmente (tamanho da área a distribuição proporcional das plantas no foco de infestação. Após a identificação, foram encontradas 18 espécies de plantas aquáticas vegetando no reservatório, das quais foram determinadas a frequência de espécie de planta aquática e a distribuição dentro do sistema de geração de energia. As espécies encontradas no reservatório foram: Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes, Paspalum repens, Cyperus brevifolius, Paspalum conspersum, Echinochloa polystachya, Egeria densa, Egeria najas, Polygonum hidropiperoides, Polygonum lapathifolium, Alternanthera philoxeroides, Eleocharis sellowiana, Nymphaea ampla, Pontederia cordata, Salvinia auriculata, Salvinia rotundifolia e Typha angustifolia. As maiores frequências relativas foram observadas em: E. azurea (36,11%, E. crassipes (16,67%, P. stratiotes (13,89%, S. auriculata (13,89%, C. brevifolius (11,11% e P. lapathifolium (6,94%.The objective of this work was to identify the aquatic plants and their infestation levels in Porto Primavera Reservoir in the state of São Paulo, Brazil, before the reservoir was filled. The aquatic vegetation in the dam (72 sites were evaluated and marked with GPS equipment. The species were identified and a visual estimate (site size of the proportional distribution of the plants in the infestation foci was carried out. After plant identification, eighteen macrophyte species were found in the dam and their frequency and distribution were determined as follows: Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes, Paspalum repens, Cyperus brevifolius

  16. Differences between Male Students' and Female Students' Perception of Professors

    Science.gov (United States)

    Tomkiewicz, Joseph; Bass, Kenneth

    2008-01-01

    This study is an empirical examination of possible differences between female and male college seniors' perceptions between male and female college professors. Subjects were presented with three variations of a scale designed to measure students' perceptions of university professors in general, female professors, and male professors. These…

  17. Report of the regional workshop in transboundary aquatic animal health issues, Bangkok, Thailand, 12-13 January, 2012

    OpenAIRE

    2012-01-01

    This workshop was implemented as part of the Transboundary Diagnostic Analysis (TDA). The main focus was on the shrimp and fish aquaculture sectors and addressed issues such as aquatic animal health and transfers of aquatic animals and plants.

  18. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in the...

  19. Aquatic Life Criteria - Copper

    Science.gov (United States)

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  20. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  1. Aquatic Life Criterion - Selenium

    Science.gov (United States)

    Documents pertaining to the 2016 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Selenium (Freshwater). These documents include what the safe levels of Selenium are in water for the majority of species.

  2. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  3. Accounting Professor Qualification in Digital Age: A Perception Study on Brazilian Professors

    Science.gov (United States)

    Vendruscolo, Maria Ivanice; Behar, Patrícia Alejandra

    2015-01-01

    This papers aims at analyzing the perception of Accounting professors about the necessary qualifications in Accounting undergraduate courses. The contribution of this study is to theoretically discuss the education of Accounting professors, with empirical data, because Accounting teaching requires specific competencies in the digital area. The…

  4. Experimental assessment of the water quality influence on the phosphorus uptake of an invasive aquatic plant: biological responses throughout its phenological stage.

    Science.gov (United States)

    Baldy, Virginie; Thiebaut, Gabrielle; Fernandez, Catherine; Sagova-Mareckova, Marketa; Korboulewsky, Nathalie; Monnier, Yogan; Perez, Thierry; Tremolieres, Michele

    2015-01-01

    Understanding how an invasive plant can colonize a large range of environments is still a great challenge in freshwater ecology. For the first time, we assessed the relative importance of four factors on the phosphorus uptake and growth of an invasive macrophyte Elodea nuttallii (Planch.) St. John. This study provided data on its phenotypic plasticity, which is frequently suggested as an important mechanism but remains poorly investigated. The phosphorus uptake of two Elodea nuttallii subpopulations was experimentally studied under contrasting environmental conditions. Plants were sampled in the Rhine floodplain and in the Northern Vosges mountains, and then maintained in aquaria in hard (Rhine) or soft (Vosges) water. Under these conditions, we tested the influence of two trophic states (eutrophic state, 100 μg x l(-1) P-PO4(3-) and hypertrophic state, 300 μg x l(-1) P-PO4(3-)) on the P metabolism of plant subpopulations collected at three seasons (winter, spring and summer). Elodea nuttallii was able to absorb high levels of phosphorus through its shoots and enhance its phosphorus uptake, continually, after an increase of the resource availability (hypertrophic > eutrophic). The lowest efficiency in nutrient use was observed in winter, whereas the highest was recorded in spring, what revealed thus a storage strategy which can be beneficial to new shoots. This experiment provided evidence that generally, the water trophic state is the main factor governing P uptake, and the mineral status (softwater > hardwater) of the stream water is the second main factor. The phenological stage appeared to be a confounding factor to P level in water. Nonetheless, phenology played a role in P turnover in the plant. Finally, phenotypic plasticity allows both subpopulations to adapt to a changing environment.

  5. U.S. Department of Agriculture/Corps of Engineers Cooperative Aquatic Plant Control Research. Annual Report for FY 1981. Biological and Chemical Control Technologies.

    Science.gov (United States)

    1983-10-01

    more to a loss of the plants than to the direct lethal effects of the low temperatures on the insects. By March, populations were again dispersing...34 ot I albigutfis population intensities as influenced by latitude and pattu in both north and south Florida, but alack of seasonality in the central...philozeroide. (Mart.) Griseb. Cabomba Cabomba carolinian. Gray Cham Chara spp. Dckweed Lemna spp. Hydrifla Hydrill aer t Royle I iypphila Hygrophila

  6. Proceedings of the Annual Meeting (21st), Aquatic Plant Control Research Program Held in Mobile, Alabama on 17-21 November 1986

    Science.gov (United States)

    1987-11-01

    of Southern Mississippi’s computer-assisted retrieval system (SCARS) was used to search Chemical Abstracts, Biological Abstracts and Agricola from...initial year will include bioassay with H. i’erticillata as the target species as well as greenhouse studies to demonstrate allelopathic capabilities...and the dishes were kept in the quarantine greenhouse where the weevil colony was being maintained. Each test continued for 10 days. Plants were

  7. The housekeeper and the professor a novel

    CERN Document Server

    Ogawa, Yoko

    2010-01-01

    He is a brilliant math Professor with a peculiar problem—ever since a traumatic head injury, he has lived with only eighty minutes of short-term memory. She is an astute young Housekeeper—with a ten-year-old son—who is hired to care for the Professor. And every morning, as the Professor and the Housekeeper are introduced to each other anew, a strange and beautiful relationship blossoms between them. Though he cannot hold memories for long (his brain is like a tape that begins to erase itself every eighty minutes), the Professor's mind is still alive with elegant equations from the past. And the numbers, in all of their articulate order, reveal a sheltering and poetic world to both the Housekeeper and her young son. The Professor is capable of discovering connections between the simplest of quantities—like the Housekeeper's shoe size—and the universe at large, drawing their lives ever closer and more profoundly together, even as his memory slips away. Yoko Ogawa's The Housekeeper and the Professo...

  8. Nutrition, illness, and injury in aquatic sports.

    Science.gov (United States)

    Pyne, David B; Verhagen, Evert A; Mountjoy, Margo

    2014-08-01

    In this review, we outline key principles for prevention of injury and illness in aquatic sports, detail the epidemiology of injury and illness in aquatic athletes at major international competitions and in training, and examine the relevant scientific evidence on nutrients for reducing the risk of illness and injury. Aquatic athletes are encouraged to consume a well-planned diet with sufficient calories, macronutrients (particularly carbohydrate and protein), and micronutrients (particularly iron, zinc, and vitamins A, D, E, B6, and B12) to maintain health and performance. Ingesting carbohydrate via sports drinks, gels, or sports foods during prolonged training sessions is beneficial in maintaining energy availability. Studies of foods or supplements containing plant polyphenols and selected strains of probiotic species are promising, but further research is required. In terms of injury, intake of vitamin D, protein, and total caloric intake, in combination with treatment and resistance training, promotes recovery back to full health and training.

  9. Invertebrates and Plants

    Science.gov (United States)

    Wendell R. Haag; Robert J. Distefano; Siobhan Fennessy; Brett D.. Marshall

    2013-01-01

    Invertebrates and plants are among the most ubiquitous and abundant macroscopic organisms in aquatic ecosystems; they dominate most habitats in both diversity and biomass and play central roles in aquatic food webs. Plants regulate and create habitats for a wide array of organisms (Cooke et al. 2005). Snail grazing and bivalve filtering profoundly alter habitats and...

  10. Effect of zinc and lead on the physiological and biochemical properties of aquatic plant Lemna minor: its potential role in phytoremediation

    Science.gov (United States)

    Jayasri, M. A.; Suthindhiran, K.

    2017-06-01

    Plants have gained importance in situ bioremediation of heavy metals. In the present study, different concentrations of zinc (Zn2+) (0.5, 5, 10, 15, 20 mg/l) and lead (Pb2+) (1, 2, 4, 6, 8 mg/l) were used to evaluate metal tolerance level of Lemna minor. L.minor were exposed to metals for 4 days and tested for its dry to fresh weight ratio (DW/FW), photosynthetic pigments production and protein content. The oxidative damage was detected by measuring catalase activity. L.minor showed tolerance against Zn2+ and Pb2+ at a concentration of 10 and 4 mg/l, respectively. Among the metals, Pb2+ showed a significant toxicity at 8 mg/l. High concentration (20 mg/l of Zn2+ and 8 mg/l of Pb2+) of the metals displayed a considerable negative effect on soluble proteins (13 fold decrease with Zn2+ and 4 fold decrease with Pb2+) and photosynthetic pigments (twofold decrease with Zn2+ and onefold decrease with Pb2+) and lead to a consequent reduction in number of fronds. Further, the catalase was greatly increased (twofold decrease with Zn2+ and sixfold decrease with Pb2+) under metal stress. The results indicate that L.minor withstands Zn2+ and Pb2+ toxicity up to the concentration of 10 and 4 mg/l, respectively. Hence, the metal tolerant property of this plant shall be exploited for bioremediation of Zinc and Lead in polluted water. Further, the detailed and wide range of heavy metal toxicity studies should be done to reveal the possible use of this plant on large scale bioremediation purpose.

  11. Professor Karel Oštir zum andenken

    Directory of Open Access Journals (Sweden)

    Bojan Čop

    1973-12-01

    Full Text Available Die Redaktion der Zeitschrift tinguistica beschloss am Anfang des Jahres 1973, den XIII.Jg. der Vollendung des fünfundachtzigsten Lebensjahres, die Professor Karel Oštir am 13. Oktober feiern sollte, zu widmen. Da sich aber das Sammeln des Materials für diesen Jahrgang sowie der Druck des XII. Jahrganges allzusehr in die Länge gezogen hatten, ist uns das unerbittliche Schicksal zuvorgekommen: am 27. Dezember 1973 ist Professor Karel Oštir sanft entschlafen. Das Leben eines der eigenartigsten Sprachwissenschaftler aller Zei ten hat sich so erfüllt. Aus einer Festschrift musste nun eine Gedenkschrift werden.

  12. Professor Stewart's casebook of mathematical mysteries

    CERN Document Server

    Stewart, Ian

    2014-01-01

    Like its wildly popular predecessors Cabinet of Mathematical Curiosities and Hoard of Mathematical Treasures, Professor Stewart's brand-new book is a miscellany of over 150 mathematical curios and conundrums, packed with trademark humour and numerous illustrations. In addition to the fascinating formulae and thrilling theorems familiar to Professor Stewart's fans, the Casebook follows the adventures of the not-so-great detective Hemlock Soames and his sidekick Dr John Watsup (immortalised in the phrase 'Watsup, Doc?'). By a remarkable coincidence they live at 222B Baker Street, just a

  13. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes.

    Science.gov (United States)

    Fuentes, Ignacio I; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M

    2014-10-01

    An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g(-1) (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g(-1) internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 1. Baseline Studies. Volume II. The Fish, Mammals, and Waterfowl of Lake Conway, Florida.

    Science.gov (United States)

    1979-12-01

    reduced. b. White amur recycle nutrients bound in aquatic macrophytes , possibly increasing the nutrient level in the water so that problems of... eutrophication , plankton blooms, and filamentous algae are aggravated. c. Sport fish population production may decline due to sim- ple displacement, direct...level fluctuations, seasonal succession of aquatic macrophytes , water quality, physical alterations, and other factors. Of course in some instances

  15. Kai Adolf Jensen, professor i almindelig patologi

    DEFF Research Database (Denmark)

    Høiby, Niels

    2016-01-01

    for the Bacillus Calmette-Guérin vaccine production and supervised many young scientists’ doctoral theses on the aspects of tuberculosis. He became internationally recognized, and he revealed an important scientific fraud in the laboratory of the Austrian professor Ernst Löwenstein (1878-1950), who claimed that he...

  16. String theorist takes over as Lucasian Professor

    Science.gov (United States)

    Banks, Michael

    2009-11-01

    String theorist Michael Green will be the next Lucasian Professor of Mathematics at Cambridge University. Green, 63, will succeed Stephen Hawking, who held the chair from 1980 before retiring last month at the age of 67 and taking up a distinguished research chair at the Perimeter Institute for Theoretical Physics in Canada (see above).

  17. Epistemology Shock: English Professors Confront Science

    Science.gov (United States)

    Barnard, Ian; Osborn, Jan

    2017-01-01

    This article raises questions and concerns regarding students from the sciences working with faculty in the humanities in interdisciplinary settings. It explores the experience of two English professors facing the privileging of "facts" and a science-based understanding of the world in their own classrooms. It poses both questions and…

  18. Understanding Asperger Syndrome: A Professor's Guide [DVD

    Science.gov (United States)

    Organization for Autism Research (NJ3), 2011

    2011-01-01

    College can be a trying time in any individual's life. For adults with Asperger Syndrome this experience can be overwhelming. This title in the new DVD series Asperger Syndrome and Adulthood focuses on educating professors, teaching assistants, and others on what it means to be a college student on the spectrum and how they might best be able to…

  19. Professor Brand Advocacy: Do Brand Relationships Matter?

    Science.gov (United States)

    Jillapalli, Ravi K.; Wilcox, James B.

    2010-01-01

    The trend among students to advocate their professors online continues to generate interest within marketing academia. Brand advocacy in products and services has played a vital role in marketing. However, no known research to date has embraced the idea of brand advocacy in marketing education. This research builds on the recent human brand…

  20. Forestry professors and students receive national recognition

    OpenAIRE

    Davis, Lynn

    2005-01-01

    Two Virginia Tech professors in the College of Natural Resources and the university's Society of American Foresters student chapter received awards for their accomplishments at the Society of American Foresters 2005 national convention held in Fort Worth, Texas, earlier this month.

  1. Two business professors receive Fulbright Scholar awards

    OpenAIRE

    Ho, Sookhan

    2005-01-01

    Virginia Tech Pamplin College of Business professors Larry French and Mahmood A. Khan have received Fulbright Scholar Awards to teach and conduct research abroad next year. Both faculty members teach in the MBA program at the university's Northern Virginia Center in metro Washington, D.C.

  2. The Supervisor Is Not the Professor

    Science.gov (United States)

    Johnson, G. Stewart; Shafer, Carl

    1970-01-01

    College educational exposure does not prepare the graduate for the human relations demands of teamwork in industry, and may not prepare the graduate for the relationship with his supervisor. Five major dimensions of difference for the student between his interaction with his professors and his new relationships with his supervisor are: degree of…

  3. "Dear Professor: I Hate You"--Anonymous

    Science.gov (United States)

    Bartlett, Thomas

    2009-01-01

    Flip through a stack of anonymous student evaluations of professors and the mild comments, even the compliments, tend to blend together. But often, hidden among them, is a dagger. Then there are the out-and-out insults. Students' comments can be more than simply mean. Sometimes student comments aren't cruel, just weird. In this article, some…

  4. Africa's New Crisis: A Dearth of Professors

    Science.gov (United States)

    Lindow, Megan

    2009-01-01

    With many professors approaching retirement. a shortage of qualified academics has reached crisis proportions at a number of African universities. The shortfall is a consequence of decades of neglect of African higher education, as donors and governments concentrated limited resources on primary and secondary schools, and young scholars who manage…

  5. Professor Jacques Cortes prantsuse keele lektoraadis

    Index Scriptorium Estoniae

    2000-01-01

    Juuni alguses külastas filoloogiateaduskonna romaani-germaani filoloogia osakonda Roueni ülikooli professor Jacques Cortes (Prantsusmaa). Ta korraldas 4. õa üliõpilastele prantsuse keele intensiivkursuse ja võttis vastu eksami ning kohtus prantsuse keele lektoraadi õppejõududega : [täistekst

  6. Microcomputing Competencies for Special Education Professors.

    Science.gov (United States)

    Blackhurst, A. Edward; And Others

    1987-01-01

    A list of microcomputing competencies associated with functions that special education professors typically perform was assessed by 148 special education faculty who use microcomputers. Word processing was rated as the single most useful competency, along with the category of providing instruction about microcomputer applications in special…

  7. Veterinary medicine professor receives national honor

    OpenAIRE

    Douglas, Jeffrey S.

    2005-01-01

    Marie-Suthers-McCabe, of Riner, Va., associate professor of small animal clinical sciences at the Virginia-Maryland Regional College of Veterinary Medicine, has been awarded the highest honor in the nation for work in the area of the "human/animal bond."

  8. CFA or CFP: A Guide for Professors

    Science.gov (United States)

    Moy, Ronald L.

    2011-01-01

    The CFA Institute and the CFP Board of Standards provide professional certifications in the field of finance. In this paper, I provide my experience with the CFA and CFP programs in order to give other professors some insight into the process of attaining the designations. I hope to provide answers to some of the questions that other faculty…

  9. Family Law and Family Studies: Professor's Views

    Science.gov (United States)

    Hicks, Mary W.; And Others

    1977-01-01

    The results of a survey of family studies faculty concerning the inclusion of family law topics in family studies courses are discussed. The professor's needs for training and resources in the area of family and the law are identified and recommendations for meeting these needs are suggested. (Author)

  10. Antimicrobial activities of endophytic fungi of the Sri Lankan aquatic plant Nymphaea nouchali and chaetoglobosin A and C, produced by the endophytic fungus Chaetomium globosum

    Directory of Open Access Journals (Sweden)

    Ranga K. Dissanayake

    2016-01-01

    Full Text Available Twenty distinct endophytic fungi were isolated from the surface-sterilized plant parts of Nymphaea nouchali and were identified using morphological and molecular techniques. At 300 µg/disc concentration, eight of the 20 fungal extracts exhibited antimicrobial activities against Staphylococcus aureus (ATCC 25923 and Bacillus cereus (ATCC 11778 while two within the eight showed activity against Pseudomonas aeruginosa (ATCC 9027 and Escherichia coli (ATCC 35218. Furthermore, investigation of the crude extract of Chaetomium globosum resulted in the isolation of two known cytochalasans, chaetoglobosin A and C, and their structures were elucidated and confirmed by mass and nuclear magnetic resonance (NMR (1H, 13C, COSY, HSQC, HMBC and tROESY spectral data. Chaetoglobosin A showed antibacterial activities against Bacillus subtilis (MIC 16 µg mL−1, Staphylococcus aureus (MIC 32 µg mL−1 and methicillin-resistant Staphylococcus aureus (MRSA, MIC 32 µg mL−1. This is the first study to report the isolation, identification and antimicrobial properties of endophytic fungi of N. nouchali in Sri Lanka.

  11. Professor Attitudes and Beliefs about Teaching Evolution

    Science.gov (United States)

    Barnes, Maryann Elizabeth

    Teaching evolution has been shown to be a challenge for faculty, in both K-12 and postsecondary education. Many of these challenges stem from perceived conflicts not only between religion and evolution, but also faculty beliefs about religion, it's compatibility with evolutionary theory, and it's proper role in classroom curriculum. Studies suggest that if educators engage with students' religious beliefs and identity, this may help students have positive attitudes towards evolution. The aim of this study was to reveal attitudes and beliefs professors have about addressing religion and providing religious scientist role models to students when teaching evolution. 15 semi-structured interviews of tenured biology professors were conducted at a large Midwestern universiy regarding their beliefs, experiences, and strategies teaching evolution and particularly, their willingness to address religion in a class section on evolution. Following a qualitative analysis of transcripts, professors did not agree on whether or not it is their job to help students accept evolution (although the majority said it is not), nor did they agree on a definition of "acceptance of evolution". Professors are willing to engage in students' religious beliefs, if this would help their students accept evolution. Finally, professors perceived many challenges to engaging students' religious beliefs in a science classroom such as the appropriateness of the material for a science class, large class sizes, and time constraints. Given the results of this study, the author concludes that instructors must come to a consensus about their goals as biology educators as well as what "acceptance of evolution" means, before they can realistically apply the engagement of student's religious beliefs and identity as an educational strategy.

  12. Aproveitamento da macrófita aquática Egeria densa como adubo orgânico Use of aquatic plant (Egeria densa as an organic fertilizer

    Directory of Open Access Journals (Sweden)

    E.V.S.B. Sampaio

    2005-06-01

    Full Text Available Grandes massas de Egeria densa são retiradas dos lagos do sistema hidrelétrico de Paulo Afonso e seu descarte tem sido problemático. O aproveitamento como adubo orgânico foi comparado com o de esterco, em plantio de milho, irrigado, a campo. Foram comparadas as doses de 20 e 40 t ha-1 de matéria seca com testemunha, sem adubo. Paralelamente, foi acompanhada a decomposição do material incorporado ao solo. A massa de E. densa decompôs-se rapidamente, restando menos de um terço após um mês e menos de 1% após dois meses. As adubações com E. densa e esterco incorporaram grande quantidade de nutrientes ao solo e resultaram em produção de grãos de milho (3,5 a 8,5 t ha-1 e palha (4,3 a 8,8 t ha-1 muito maior que a da testemunha (0,3 e 1,2 t ha-1. Em média, as produções com E. densa (grãos, 7,7 t ha-1 foram maiores que as com esterco (4,2 t ha-1, sem diferenças significativas entre doses, possivelmente porque a massa de E. densa libera nutrientes mais rapidamente. Os teores de metais pesados e outros elementos de E. densa ficaram dentro da faixa permitida para adubos orgânicos e não afetaram o milho. O aproveitamento como adubo orgânico parece recomendável.The removal of large masses of Egeria densa out of the lakes of Paulo Afonso hydroelectric plant complex has been problematic. Their use as organic fertilizer was compared to that of cattle manure, in an irrigated corn field. Doses of 20 and 40 t ha-1 of dry matter were compared to a control, without fertilizer. Simultaneously, decomposition of the material in the soil was monitored. The E. densa mass decomposed rapidly, with less than a third remaining after one month and less than 1% after two months. Incorporations with both E. densa and manure added large quantities of nutrients to the soil and resulted in larger grain (3.5 to 8.5 t ha-1 and straw (4.3 to 8.8 t ha-1 productions than those of the control (0.3 and 1.2 t ha-1. Productions with E. densa (grain, 7.7 t ha-1, on

  13. Ubiquitous Detection of Artificial Sweeteners and Iodinated X-ray Contrast Media in Aquatic Environmental and Wastewater Treatment Plant Samples from Vietnam, The Philippines, and Myanmar.

    Science.gov (United States)

    Watanabe, Yuta; Bach, Leu Tho; Van Dinh, Pham; Prudente, Maricar; Aguja, Socorro; Phay, Nyunt; Nakata, Haruhiko

    2016-05-01

    Water samples from Vietnam, The Philippines, and Myanmar were analyzed for artificial sweeteners (ASs) and iodinated X-ray contrast media (ICMs). High concentrations (low micrograms per liter) of ASs, including aspartame, saccharin, and sucralose, were found in wastewater treatment plant (WWTP) influents from Vietnam. Three ICMs, iohexol, iopamidol, and iopromide were detected in Vietnamese WWTP influents and effluents, suggesting that these ICMs are frequently used in Vietnam. ASs and ICMs were found in river water from downtown Hanoi at concentrations comparable to or lower than the concentrations in WWTP influents. The ASs and ICMs concentrations in WWTP influents and adjacent surface water significantly correlated (r (2) = 0.99, p rivers in Vietnam. Acesulfame was frequently detected in northern Vietnamese groundwater, but the concentrations varied spatially by one order of magnitude even though the sampling points were very close together. This implies that poorly performing domestic septic tanks sporadically leak household wastewater into groundwater. High acesulfame, cyclamate, saccharin, and sucralose concentrations were found in surface water from Manila, The Philippines. The sucralose concentrations were one order of magnitude higher in the Manila samples than in the Vietnamese samples, indicating that more sucralose is used in The Philippines than in Vietnam. Acesulfame and cyclamate were found in surface water from Pathein (rural) and Yangon (urban) in Myanmar, but no ICMs were found in the samples. The ASs concentrations were two-three orders of magnitude lower in the samples from Myanmar than in the samples from Vietnam and The Philippines, suggesting that different amounts of ASs are used in these countries. We believe this is the first report of persistent ASs and ICMs having ubiquitous distributions in economically emerging South Asian countries.

  14. Yuriko and Michael Renardy reappointed Class of 1950 Professors

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Yuriko and Michael Renardy, professors of mathematics in the College of Science at Virginia Tech, have been reappointed as the Virginia Tech Class of 1950 Professors by the Virginia Tech Board of Visitors.

  15. Pelargonic acid - a potential organic aquatic herbicide for duckweed management

    Science.gov (United States)

    Duckweed (Lemna spp.) are small, free floating aquatic plants that flourish on stagnant, or slow moving, water surfaces throughout the continental U.S. Members of the genus are among the smallest flowering plants, providing food for fish and fowl, but their aggressive growth and invasive habit make...

  16. Aquatic Environment 2000

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.

    The report summarizes the results of the Danish Aquatic Monitoring and Assessment Programme 1998-2003. Danish Environmental Protection Agency 2000: NOVA-2003. Programbeskrivelse for det nationale program for overvågning af vandmiljøet 1998-2003. 397 pp. - Redegørelse fra Miljøstyrelsen nr. 1 (in...

  17. Investigating Aquatic Dead Zones

    Science.gov (United States)

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  18. Aquatic Equipment Information.

    Science.gov (United States)

    Sova, Ruth

    Equipment usually used in water exercise programs is designed for variety, intensity, and program necessity. This guide discusses aquatic equipment under the following headings: (1) equipment design; (2) equipment principles; (3) precautions and contraindications; (4) population contraindications; and (5) choosing equipment. Equipment is used…

  19. Categorization of Quantum Mechanics Problems by Professors and Students

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2010-01-01

    We discuss the categorization of 20 quantum mechanics problems by physics professors and undergraduate students from two honours-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty…

  20. E-Mail from Professor Enhances Student Motivation and Attitudes

    Science.gov (United States)

    Legg, Angela M.; Wilson, Janie H.

    2009-01-01

    Traditionally, professors use the first day of class to build rapport. However, current technology allows professors to contact students prior to the first day of class. This study assessed how the receipt of a welcoming e-mail from a female professor 1 week before the first day of class affected student motivation and attitudes toward the…

  1. Connect and Thrive: Perspectives from a Newly Tenured Professor

    Science.gov (United States)

    Ciocchetti, Corey A.

    2011-01-01

    This essay encapsulates the author's perspective on how average professors can become highly effective professors. The author asserts that the secret rests in the ability to genuinely connect with students. Connecting really matters--even if it takes some personality adaptation and thrusts academics out of their comfort zones. Many professors fail…

  2. Anti-Fat Bias by Professors Teaching Physical Education Majors

    Science.gov (United States)

    Fontana, Fabio; Furtado, Ovande, Jr.; Mazzardo, Oldemar, Jr.; Hong, Deockki; de Campos, Wagner

    2017-01-01

    Anti-fat bias by professors in physical education departments may interfere with the training provided to pre-service teachers. The purpose of this study was to evaluate the attitudes of professors in physical education departments toward obese individuals. Professors from randomly selected institutions across all four US regions participated in…

  3. 26 CFR 509.115 - Visiting professors or teachers.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Visiting professors or teachers. 509.115...) REGULATIONS UNDER TAX CONVENTIONS SWITZERLAND General Income Tax § 509.115 Visiting professors or teachers. (a) General. Pursuant to Article XII of the convention, a professor or teacher, a nonresident alien who is a...

  4. Variables That Can Affect Student Ratings of Their Professors

    Science.gov (United States)

    Gotlieb, Jerry

    2013-01-01

    Attribution theory was applied to help predict the results of an experiment that examined the effects of three independent variables on students' ratings of their professors. The dependent variables were students' perceptions of whether the professor caused the students' grades and student satisfaction with their professor. The results suggest…

  5. Journal of Aquatic Sciences: Submissions

    African Journals Online (AJOL)

    Acceptable topics include aquatic biology, aquatic resources management, aquatic ecotoxicology and pollution, fish physiology, nutrition, health, breeding, population dynamics, fish processing and preservation. Categories of articles include the following: v Full research papers must not exceed 18 manuscript pages ...

  6. Erratum: Effects of Water Table Control by Farm-Oriented Enhancing Aquatic System on Photosynthesis, Nodule Nitrogen Fixation, and Yield of Soybeans [ Plant Production Science Vol.15(2012) No.2 P132-143

    National Research Council Canada - National Science Library

    Shimada, Shinji; Hamaguchi, Hideo; Kim, Yeonghoo; Matsuura, Kazuya; Kato, Masayasu; Kokuryu, Takuo; Tazawa, Junko; Fujimori, Shinsaku

    2014-01-01

    Regarding the article Vol. 15(2): 132-143, 2012. Shimada et al. “Effects of Water Table Control by Farm-oriented Enhancing Aquatic System on Photosynthesis, Nodule Nitrogen Fixation, and Yield of Soybean...

  7. Science to support aquatic animal health

    Science.gov (United States)

    Purcell, Maureen K.; Harris, M. Camille

    2016-10-18

    Healthy aquatic ecosystems are home to a diversity of plants, invertebrates, fish and wildlife. Aquatic animal populations face unprecedented threats to their health and survival from climate change, water shortages, habitat alteration, invasive species and environmental contaminants. These environmental stressors can directly impact the prevalence and severity of disease in aquatic populations. For example, periodic fish kills in the upper Chesapeake Bay Watershed are associated with many different opportunistic pathogens that proliferate in stressed fish populations. An estimated 80 percent of endangered juvenile Puget Sound steelhead trout die within two weeks of entering the marine environment, and a role for disease in these losses is being investigated. The introduction of viral hemorrhagic septicemia virus (VHSV) into the Great Lakes—a fishery worth an estimated 7 billion dollars annually—resulted in widespread fish die-offs and virus detections in 28 different fish species. Millions of dying sea stars along the west coast of North America have led to investigations into sea star wasting disease. U.S. Geological Survey (USGS) scientists are assisting managers with these issues through ecological investigations of aquatic animal diseases, field surveillance, and research to promote the development of mitigation strategies.

  8. Spotlight on CERN : Professor Michel Spiro

    CERN Multimedia

    CERN video productions

    2011-01-01

    20 Member states throughout Europe. A geographical expansion underway. A worldwide, international collaboration and a scientific challenge on a scale second to none. In view of this complexity, how is CERN managed? This is the remit of the CERN council, which notably defines the strategic programmes, annual objectives, approves the annual budget and nominates the directorate. I am pleased to welcome Professor Michel Spiro, scientific director of the CNRS in France and CERN Council presdient since 2010. On today’s agenda: Expansion, innovation and communication. Hello and welcome Professor.. François et Stéphan are of course with me today to discuss such matters as antimatter, press and we will also be talking water and towers… I will say no more. It’s good to see you both ! And welcome to you all for this latest edition of Spotlight on CERN.

  9. 31 July 2014 - Professor M. Kastner

    CERN Multimedia

    Egli, Laurent

    2014-01-01

    MIT Faculty Member Donner Professor of Physics Massachusetts Institute of Technology United States of America, Prof. M. Kastner visiting the LHC tunnel at Point 5 with Beams Department M. Solfaroli Camillocci, LHC superconducting magnet assembly hall visit with L. Rossi and R. Principe, LHC Computing Grid Project presentation and computer centre visit with I. Bird and signing the guest book with CERN Director-General R. Heuer.

  10. [Homage to Professor Dr. Nicasio Etchepareborda].

    Science.gov (United States)

    1998-11-01

    During a solemn academic act, de Main Classroom of the Facultad de Odontologia de Buenos Aires was named after Prof. Dr. Nicasio Etchepareborda. He has been the first professor at the Escuela de Odontologia and its organizer, after having obtained his Dentistry degree at the Dental School of Paris, in 1882. The new school was founded in 1891, and its activities began the following year.

  11. Levantamento de plantas daninhas aquáticas no reservatório de Alagados, Ponta Grossa-PR Assessment of aquatic plants from Alagados dam, Ponta Grossa-PR

    Directory of Open Access Journals (Sweden)

    D.C Rocha

    2011-06-01

    Full Text Available O monitoramento de macrófitas da represa Alagados um reservatório artificial de água que abastece parcialmente a população do município de Ponta Grossa-PR se faz necessário, uma vez que resíduos urbanos, bem como dejetos de áreas rurais, são descartados direta ou indiretamente nesse ambiente. Os objetivos deste trabalho foram realizar o inventário de plantas aquáticas coletadas entre agosto de 2007 e julho de 2008 no entorno do lago, como medida de monitoramento da área; indicar a frequência das espécies e apresentar um diagnóstico sobre o crescimento populacional destas; e identificar áreas onde a colonização por macrófitas é intensa, podendo tornar-se problema ambiental. Para realizar esse inventário, foram efetuadas 10 coletas em 48 pontos de amostragem ao longo das margens do lago da represa. Exsicatas foram depositadas no Herbário da Universidade Estadual de Ponta Grossa (HUPG. Foram amostradas 54 espécies, distribuídas em 16 famílias de angiospermas, 8 monocotiledôneas e 8 dicotiledôneas, e outras duas famílias de pteridófitas.A check-list of the macrophytes in the Alagados artificial dam, which supplies part of the population of Ponta Grossa-PR, is necessary, since urban and rural waste is dropped directly or indirectly into this environment. The objectives of this work were to make an inventory of the aquatic plants collected between August 2007 and July 2008 in the lake surroundings to monitor the area; to indicate species frequency, to present a diagnosis on species population growth; and to identify areas where colonization by macrophytes is intense and could become an environmental problem. To carry out this inventory, 10 collections were conducted in 48 sampling points along the margins of the dam's lake. Exsiccates were deposited in the Herbarium of the Universidade Estadual de Ponta Grossa (HUPG. A total of 54 species were sampled, distributed in 16 families of flowering plants, 8 monocotyledons and 8

  12. In memory of Professor Paolo Talamucci

    Directory of Open Access Journals (Sweden)

    Cantiani M

    2010-05-01

    Full Text Available Paolo Talamucci, Full Professor of Range Management at the Università degli Studi in Florence from 1975 to 2001, passed away on 27th November 2009, after a brief and unrelenting illness. Professor Talamucci spent many long years in the field of research, in both Mediterranean and Alpine regions. His research, profoundly rooted in the territory he was studying, holistic in its approach and rigorously scientific, was characterized by a strong interdisciplinary element, seeking always to take into account the totality of the components of the ecosystem. Professor Talamucci was one of the first scholars of the pastoral system to highlight the problems related to the abandonment of traditional animal husbandry in mountainous zones and to look for ways to counteract the undesirable transformation of the landscape and the consequent loss of biodiversity. His curriculum and his numerous scientific publications bear testimony not only to the prestigious research institutes, world-wide, with which he was associated, but also to the important international dimension of his research.

  13. APOSENTADORIA: como professores vivenciam este momento?

    Directory of Open Access Journals (Sweden)

    Cristiane Nervis Conrado Machado

    2017-05-01

    Full Text Available O presente artigo buscou compreender as implicações que a aposentadoria causa na vida de professores, levando em conta o significado que a aposentadoria representa à estes, considerando os pontos de maior mudança após a aposentadoria, bem como os aspectos positivos e negativos causados pela aposentadoria na percepção dos sujeitos da pesquisa. Para tanto, foi realizada uma pesquisa qualitativa caracterizada como exploratória e descritiva com professores aposentados por mais de dois anos, com idade entre 58 e 66 anos, através de entrevistas individuais, com roteiros semiestruturados. A análise dos dados foi por meio da análise de conteúdo de Bardin (2011. Entre os principais resultados, destaca-se o significado de “liberdade” que a aposentadoria representa, a rotina como maior mudança e flexibilidade de horários dentre os pontos positivos e a falta dos alunos como aspecto negativo, contudo, pode-se perceber que a aposentadoria possibilitou e contribuiu para que os professores pudessem desfrutar de momentos de lazer, dedicando cuidado à família e realizando seus anseios e vontades.

  14. Aquatic Plant Control Research Program: Aquatic Plant Identification and Herbicide Use Guide. Volume 2. Aquatic Plants and Susceptibility to Herbicides

    Science.gov (United States)

    1988-11-01

    12 mm in diameter, often reddish in color. Leaves about 0.5 mm long. Reproductive structures visible only through a microscope. Habitat: (FA;O...into threadlike divisions resembling roots. Reproductive structures formed at base of floating leaves. Habitat: (FA;O). Ponds and canals high in...123-230 Fathead minnow 2,4-D DMA (49%) Static 96 245-458 Amphipod 2,4-D BEE (62.5%) Static 96 4.5-8.3 ( Gammarus fasciatus) Cladoceran 2,4-D BEE (62.5

  15. Aquatic Nuisance Species Locator

    Science.gov (United States)

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  16. Microplastic in Aquatic Ecosystems.

    Science.gov (United States)

    Ivleva, Natalia P; Wiesheu, Alexandra C; Niessner, Reinhard

    2017-02-06

    The contamination of marine and freshwater ecosystems with plastic, and especially with microplastic (MP), is a global ecological problem of increasing scientific concern. This has stimulated a great deal of research on the occurrence of MP, interaction of MP with chemical pollutants, the uptake of MP by aquatic organisms, and the resulting (negative) impact of MP. Herein, we review the major issues of MP in aquatic environments, with the principal aims 1) to characterize the methods applied for MP analysis (including sampling, processing, identification and quantification), indicate the most reliable techniques, and discuss the required further improvements; 2) to estimate the abundance of MP in marine/freshwater ecosystems and clarify the problems that hamper the comparability of such results; and 3) to summarize the existing literature on the uptake of MP by living organisms. Finally, we identify knowledge gaps, suggest possible strategies to assess environmental risks arising from MP, and discuss prospects to minimize MP abundance in aquatic ecosystems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Visit of Professor Shigehiko Hasumi. President of Tokyo University, Japan, Professor Kazuo Okamoto, Head of Graduate School of Mathematical Sciences, Professor Toshiteru Matsuura, Head of Graduate School of Arts and Sciences

    CERN Multimedia

    Patrice Loiez

    1999-01-01

    Visit of Professor Shigehiko Hasumi. President of Tokyo University, Japan, Professor Kazuo Okamoto, Head of Graduate School of Mathematical Sciences, Professor Toshiteru Matsuura, Head of Graduate School of Arts and Sciences

  18. Energy from aquatic plant wastewater treatment systems

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.

    1979-01-01

    Water hyacinth (Eichhornia crassipes), duckweed (Spirodela sp. and Lemma sp.), water pennywort (Hydrocotyle ranunculoides), and kudzu (Pueraria lobata) were anaerobically fermented using an anaerobic filter technique that reduced the total digestion time from 90 days to an average of 23 days and produced 0.14-0.28 cu m CH4/kg (dry weight) (2.3-4.5 cu ft/lb) from mature filters. The anaerobic filter provided a large surface area for the anaerobic bacteria to establish and maintain an optimum balance of facultative, acid-forming, and methane-producing bacteria. Consequently the efficiency of the process was greatly improved over prior batch fermentations.

  19. Carp Control Techniques for Aquatic Plant Establishment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Over the years, fish and wildlife habitat in the Great Lakes basin has been dramatically altered by many factors including water level regulation, the introduction...

  20. State of Washington Aquatic Plant Management Program

    Science.gov (United States)

    1979-10-01

    ground and is an important area for waterfowl, long-billed curlew, grouse, grasshopper sparrow, and the white-tailed jackrabbit. Much of the natural...fetotoxicity, and mutagenicity (diquat has been shown to increase DNA synthesis in human cell cul- tures). Public exposure should be limited to the...Pesticide induced DNA damage and its repair in cultured human cells. Mutation Research, 42, pp. 161-174. - Harto R. W. ettal., 1977, In Vitro Assessment