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Sample records for watermilfoil myriophyllum spicatum

  1. Unraveling the biogeographic origins of the Eurasian watermilfoil (Myriophyllum spicatum) invasion in North America.

    Science.gov (United States)

    Moody, Michael L; Palomino, Nayell; Weyl, Philip S R; Coetzee, Julie A; Newman, Raymond M; Harms, Nathan E; Liu, Xing; Thum, Ryan A

    2016-04-01

    Using phylogeographic analyses to determine the geographic origins of biological invaders is important for identifying environmental adaptations and genetic composition in their native range as well as biocontrol agents among indigenous herbivores. Eurasian watermilfoil (Myriophyllum spicatum) and its hybrid with northern watermilfoil (M. sibiricum) are found throughout the contiguous United States and southern Canada, forming one of the most economically costly aquatic plant invasions in North America, yet the geographic origin of the invasion remains unknown. The objectives of our study included determining the geographic origin of Eurasian watermilfoil in North America as well as the maternal lineage of the hybrids. DNA sequence data from a cpDNA intron and the nrDNA ITS region were compiled for accessions from 110 populations of Eurasian watermilfoil and hybrids from North America and the native range (including Europe, Asia, and Africa). Datasets were analyzed using statistical parsimony and Bayesian phylogenetics to assess the geographic origin of the invasion. The two Eurasian watermilfoil cpDNA haplotypes in North America are also found from China and Korea, but not elsewhere in the native range. These haplotypes did not overlap and were limited in native geographic range. The ovule parent for hybrids can come from either parental lineage, and multiple haplotypes from both parental species were found. The geographic origin of this prolific aquatic plant invasion of North America is in Asia. This provides critical information to better understand the invasion pathway and inform management into the future. © 2016 Botanical Society of America.

  2. Potential utility of environmental DNA for early detection of Eurasian watermilfoil (Myriophyllum spicatum)

    Science.gov (United States)

    Newton, Jeremy; Sepulveda, Adam; Sylvester, K; Thum, Ryan

    2016-01-01

    Considering the harmful and irreversible consequences of many biological invasions, early detection of an invasive species is an important step toward protecting ecosystems (Sepulveda et al. 2012). Early detection increases the probability that suppression or eradication efforts will be successful because invasive populations are small and localized (Vander Zanden et al. 2010). However, most invasive species are not detected early because current tools have low detection probabilities when target species are rare and the sampling effort required to achieve acceptable detection capabilities with current tools is seldom tractable (Jerde et al. 2011). As a result, many invasive species go undetected until they are abundant and suppression efforts become costly. Novel DNA-based surveillance tools have recently revolutionized early detection abilities using environmental DNA (eDNA) present in the water (Darling and Mahon 2011, Bohmann et al. 2014). In brief, eDNA monitoring enables the identification of organisms from DNA present and collected in water samples. Aquatic and semiaquatic organisms release DNA contained in sloughed, damaged, or partially decomposed tissue and waste products into the water and molecular techniques allow this eDNA in the water column to be identified from simple and easy-tocollect water samples (Darling and Mahon 2011). Despite limited understanding of the production, persistence, and spread of DNA in water (Barnes et al. 2014), eDNA monitoring has been applied not only to invasive species (Jerde et al. 2011), but also to species that are rare, endangered, or highly elusive (Spear et al. 2014). However, most eDNA research and monitoring has focused on detection of invertebrates and vertebrates and less attentionhas been given to developing eDNA techniques for detecting aquatic invasive plants. Eurasian watermilfoil (EWM; Myriophyllum spicatum L.) is an invasive species for which improved early detection would be particularly helpful. Advanced

  3. Evidence of Hybridity in Invasive Watermilfoil (Myriophyllum) Populations

    National Research Council Canada - National Science Library

    Michael L. Moody; Donald H. Les

    2002-01-01

    .... Our studies of invasive watermilfoil (Myriophyllum) populations revealed widespread polymorphisms in biparentally inherited nuclear ribosomal DNA sequences, which were not detected in populations of native North American species...

  4. Selective Control of Eurasian Watermilfoil and Curlyleaf Pondweed in Noxon Rapids Reservoir, Montana: Herbicide Small-Plot Evaluations, 2010-2011

    Science.gov (United States)

    2014-03-01

    sibiricum Komarov Northern watermilfoil Myriophyllum spicatum L. Eurasian watermilfoil Najas flexilis L. (Willd.) Rost & Schmidt Slender naiad...54 21† 7* Myriophyllum spicatum L. Eurasian watermilfoil 42 20† 13* Najas flexilis L. (Willd.) Rost & Schmidt Slender naiad 0 0 1 Nitella sp...stargrass 11 40† 31* Myriophyllum sibiricum Komarov Northern watermilfoil 41 42 14* Myriophyllum spicatum L. Eurasian watermilfoil 70 30† 24* Najas

  5. Distribution and Abundance of Eurasian Watermilfoil (Myriophyllum spicatum L.) and Curly-Leaf Pondweed (Potamogeton crispus L.) in Shawano Lake, Wisconsin

    Science.gov (United States)

    2007-09-01

    Najas spp. Naiad N Submersed 13.4 Nuphar advena (Aiton) Aiton f. Yellow pond lily N Floating 1.6 Nymphaea odorata Aiton White water lily N Floating 0.3...M. sibiricum Komarov 7.7 (1.53) 4 M. spicatum L. 96.99 (21.68) 30 Najas spp. 20.15 (5.21) 43 Potamogeton amplifolius Tuck. 10.05 (6.55) 10 P

  6. Remote sensing of Myriophyllum spicatum L. in a shallow, eutrophic lake

    Science.gov (United States)

    Gustafson, T. D.; Adams, M. S.

    1973-01-01

    An aerial 35 mm system was used for the acquisition of vertical color and color infrared imagery of the submergent aquatic macrophytes of Lake Wingra, Wisconsin. A method of photographic interpretation of stem density classes is tested for its ability to make standing crop biomass estimates of Myriophyllum spicatum. The results of film image density analysis are significantly correlated with stem densities and standing crop biomass of Myriophyllum and with the biomass of Oedogonium mats. Photographic methods are contrasted with conventional harvest procedures for efficiency and accuracy.

  7. Chemical composition and in vitro anti-algal activity of Potamogeton crispus and Myriophyllum spicatum extracts

    Directory of Open Access Journals (Sweden)

    Amany M. Haroon

    2016-12-01

    Full Text Available The aim of this work was to investigate and compare the phytochemical constituents and anti-algal activities of crude extracts from dry macrophytes species, Potamogeton crispus and Myriophyllum spicatum. Organic solvents differed in polarity including petroleum ether, methylene chloride, chloroform, acetone and methanol were used to extract the phytochemical compounds and gas chromatograph–mass spectrometry (GC–MS analyzer was used for the detection of these compounds. Generally, the results indicated that the composition and mass fraction of phytochemical constituents varied with plant species and extraction solvents. The growth inhibition effects of separate and mixed plants extracts on Pseudokirchneriella subcapitata were studied. In addition, the effects of mixed extracts on ten taxonomically different freshwater microalgae species, using the single-species and mixed culture species tests were also studied. Among the five different extracts tested chloroform extract and mixed extracts of the two plant species showed the highest anti-algal potential with P. subcapitata. The sensitivity of microalgae species tested in single-species cultures to P. crispus and M. spicatum extracts found to be group-specific, in which cyanophyte Anabaena flos-aquae var. treleasei and the diatoms Gomphoneis eriense var. apiculate and Tryblionella hungarica were more sensitive compared to the tested green microalgae species. In addition, the inhibitory effects of macrophyte extracts decreased for the mixed microalgae cultures. The extracts of P. crispus and M. spicatum showed the presence of some bioactive compounds that could contribute toward the phyto-algicidal properties of these plants.

  8. Aquatic microcosm assessment of the effects of tylosin on Lemna gibba and Myriophyllum spicatum

    Energy Technology Data Exchange (ETDEWEB)

    Brain, Richard A. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Bestari, Ketut [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Sanderson, Hans [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Hanson, Mark L. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Wilson, Christian J. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Johnson, David J. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Sibley, Paul K. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Solomon, Keith R. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada)]. E-mail: ksolomon@uoguelph.ca

    2005-02-01

    Tylosin is a macrolide antibiotic commonly used for therapeutic treatment and prophylaxis in livestock. As part of a larger ecotoxicological study, the potential phytotoxic effects of tylosin on the rooted macrophyte Myriophyllum spicatum and the floating macrophyte Lemna gibba were assessed under semi-field conditions using 15 12000-L microcosms. Concentrations of 0, 10, 30, 300 {mu}g/L (n = 3), and 600, 1000, and 3000 {mu}g/L (n = 1) were evaluated as part of separate ANOVA and regression analyses over an exposure period of 35 days. Fate of tylosin was monitored over time in the highest three treatments, where dissipation followed pseudo-first order kinetics with associated half-lives ranging from 9 to 10 days. For both M. spicatum and L. gibba, tylosin was found to cause no biologically significant changes to any endpoint assessed compared to controls at a Type I error rate of 0.1. However, subsequent power analyses revealed that there was generally insufficient power to declare that there were no significant differences at a Type II error rate of 0.2. Conclusions concerning biologically significant impacts were therefore further assessed based on other statistical criteria including comparisons of percent differences between replicated treatments and controls, minimum significant and minimum detectable differences, and coefficients of variation. Based on these criteria, at an ecological effect size of >20% change, tylosin was concluded to elicit no biologically or ecologically significant toxicity to M. spicatum or L. gibba. A hazard quotient assessment indicated that tylosin poses little risk to either species of macrophyte, with an HQ value calculated to be nearly three orders of magnitude below 1 (0.002). - Tylosin is not expected to have ecologically significant effects on Ontario freshwater macrophytes.

  9. Plant-substrate interactions and below substrate biomass dynamics: a continuation of studies concerning potential restriction of the introduced aquatic weed 'Myriophyllum spicatum' l. (Eurasian water milfoil) II

    Energy Technology Data Exchange (ETDEWEB)

    Brenkert, A.L.; Amundsen, C.C.

    1982-04-01

    From the study's data analysis, it was concluded that the prediction of nuisance growth of Eurasian watermilfoil depends not only on sediment phosphorus, nitrate-nitrogen and ammonia-nitrogen, but potassium levels as well. Higher water temperatures, together with non-exposure to wave action and water stream flow, likely accounts for the development of the larger standing crop of Eurasian water milfoil within the study of the Melton Hill Reservoir. Myriophyllum spicatum was collected monthly from five study sites. Whole plant samples were collected from similar bottom contour plots via SCUBA. Sediment samples were collected using a Ponar Grab, and water column measurements were taken with a YSI temperature and conductivity meter. Sediment samples were air dried and sieved. Organic matter, available phosphorus, potassium and sediment pH, and sediment nitrate were determined. Sediment texture was determined gravimetrically.

  10. Sucrose modifies growth and physiology in axenically grown Myriophyllum spicatum with potential effects on the response to pollutants.

    Science.gov (United States)

    Nuttens, Andréïna; Gross, Elisabeth Maria

    2017-04-01

    Sucrose as a carbon source in axenic tests affects plant growth and physiology. The high sucrose concentration in Organisation for Economic Co-operation and Development (OECD) guideline 238 for the submerged growing aquatic plant Myriophyllum spicatum might modify pollutant effects, thus impairing environmental risk assessment. In a factorial design experiment with axenic M. spicatum exposed to 3 sucrose concentrations (no, low, and high) with or without cadmium, growth, dry matter content, content in pigments or phenolic compounds, and elemental stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) were measured. The results show that sucrose is crucial for growth but can be used at lower concentrations than currently considered. Sucrose-treated plants had higher dry matter content and C content but lower contents of chlorophyll and N. Cadmium affected the content in chlorophyll, phenolic compounds, and elemental stoichiometry. Interactive effects were observed on length growth, C and N content, and the C:N and N:P molar ratios. Remarkably, cadmium led to increased shoot length at low, but not at high, sucrose concentration. This contrasting effect might result from differences in osmotic potential caused by sucrose. Overall, the results suggest a strong effect of sucrose concentration on the growth and physiology of M. spicatum and modifications of the response to cadmium. Further studies should establish the lowest sucrose level needed to account for realistic environmental risk assessment based on the axenic OECD 238. Environ Toxicol Chem 2017;36:969-975. © 2016 SETAC. © 2016 SETAC.

  11. Study on the mechanism of allelopathic influence on cyanobacteria and chlorophytes by submerged macrophyte (Myriophyllum spicatum) and its secretion.

    Science.gov (United States)

    Zhu, Junying; Liu, Biyun; Wang, Jing; Gao, Yunni; Wu, Zhenbin

    2010-06-10

    For revealing the mechanism of allelopathic influence on phytoplankton by aquatic macrophytes, the growth and photosynthetic activities of cyanobacteria Microcystis aeruginosa and the chlorophyte Selenastrum capricornutum were investigated when they coexisted with submerged macrophyte Myriophyllum spicatum and were exposed to allelopathic polyphenols: pyrogallic acid (PA), gallic acid (GA), ellagic acid (EA) and (+)-catechin (CA). According to the results of coexistence assays, the non-photochemical quenching (NPQ) and effective quantum efficiency (YII) of M. aeruginosa were affected earlier and more rapidly than the cell density. However, the influence of M. spicatum on S. capricornutum was not found. When the Toxicity Index (TI) was applied to evaluate the combined effects of binary and multiple mixtures of polyphenols, it was found that the four tested polyphenols with the proportion identified in the M. spicatum-cultured solution were observed to present synergistic effect (0.36-0.49) according to the cell density, NPQ and YII of M. aeruginosa. With the combined effects of polyphenols on S. capricornutum, only additive action (0.52-1.62) was found. On the other hand, PA (2.97mgL(-1)), GA (2.65mgL(-1)) caused significant reductions of photosystem II (PSII) and whole electron transport chain activities of M. aeruginosa by 71.43 and 18.37%, 70.95 and 40.77% (Pelectron transport activities of the tested organisms. These results indicate that the reduction in photosynthetic activity of M. aeruginosa and the synergistic effect of allelochemicals may be two important causes for the inhibition of undesired phytoplankton by submersed macrophytes in natural aquatic ecosystems, and PSII in cyanobacteria is considered to be one of the target sites attacked by allelopathic polyphenols.

  12. Concurrently inhibitory and allelopathic effects of allelochemicals secreted by Myriophyllum spicatum on growth of blue-green algae; Hozakinofusamo ga hoshutsushita areropashi busshitsu no aisorui ni taisuru fukugo sayo oyobi areropashi koka no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, S.; Inoue, Y.; Hosomi, M.; Murakami, A. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan)

    1998-10-10

    This paper describes effects of allelochemicals secreted by Myriophyllum spicatum on growth of blue-green algae. In order to propose an effective growth inhibitory method of blue-green algae with less impact on the ecosystem, biological interaction (allelopathy) between large aquatic plants and algae was investigated. Pyrogallic acid, gallic acid, catechin and ellagic acid secreted by M. spicatum provided growth inhibitory effects of blue-green algae (Microcyctis aeruginosa), individually. Complex interaction and allelopathic contribution of these four polyphenols were evaluated. By comparing the actual effects with the expected values, synergetic growth inhibitory effects were recognized by adding four polyphenols at the same time. Furthermore, growth inhibitory effects were evaluated for actual culture solution of M. spicatum and simulated culture solution made by four polyphenols. As a result, it was found that these four polyphenols relate to allelopathy of M. spicatum. 25 refs., 6 figs., 4 tabs.

  13. Effects of epiphytic algae on biomass and physiology of Myriophyllum spicatum L. with the increase of nitrogen and phosphorus availability in the water body.

    Science.gov (United States)

    Song, Yu-Zhi; Wang, Jin-Qi; Gao, Yong-Xia

    2017-04-01

    The disappearance of submerged vascular macrophytes in shallow eutrophic lakes is a common phenomenon in the world. To explore the mechanism of the decline in submerged macrophyte abundance due to the growth of epiphytic algae along a nutrient gradient in eutrophic water, a 2 × 3 factorial experiment was performed over 4 weeks with the submerged macrophyte (Myriophyllum spicatum L.) by determining the plant's biomass and some physiological indexes, such as chlorophyll (Chl) content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in the leaves of M. spicatum L. on days 7, 14, 21, and 28, which are based on three groups of nitrogen and phosphorus levels in the water body (N-P [mg L-1]: NP1 0.5-0.05, NP2 2.5-0.25, NP3 4.5-0.45) and two levels of epiphytic algae (the epiphytic algae group and the control group). Epiphytic algal biomass was also assayed. The results indicated that epiphytic algal biomass remarkably enhanced in the course of the experiment with elevated levels of nitrogen and phosphorus in the water. Under the same level of nutrient condition, plants' biomass accumulation and Chl content were higher in the control group than that in the epiphytic algae group, respectively, while MDA content and SOD activity in the former were lower than that in the latter. The influences of epiphytic algae on the biomass accumulation and Chl content and MDA content became greater and greater with elevated levels of nutrients. In general, in this experiment, water nutrients promoted the growth of both epiphytic algae and submerged plants, while the growth of epiphytic algae hindered submerged macrophytes' growth by reducing Chl content and promoting peroxidation of membrane lipids in plants.

  14. Aquatic Plant Control Research Program. Growth and Rooting Depth Characteristics of Hydrilla Verticillata (L.f.) Royle and Myriophyllum Spicatum L. on Fertilized and Unfertilized Sediments

    Science.gov (United States)

    1994-05-01

    Bremner, J. M. (1965). "Inorganic forms of nitrogen." Methods of soil analy- sis, Part 2: Chemical and microbiological properties . C. A. Black, ed... demands of Myriophyllum and Hydrilla were reflected in patterns of N and P removal from low-N sediment (Fig- ures 13 and 14). Depressed concentrations of...Cambridge. Barkham, J. P. (1980). "Population dynamics of the wild daffodil ( Narcissus pseudonarsissus) Il. Oranges in number of shoots and flowers

  15. Selective Control of Eurasian Watermilfoil and Curlyleaf Pondweed Using Low Doses of Endothall Combined With 2,4-D

    Science.gov (United States)

    2006-10-01

    watermilfoil and pondweeds such as curlyleaf pondweed, Illinois pondweed (Potamogeton illinoensis Morong.), southern naiad [ Najas guadalupensis...canadensis X X b X a X Myriophyllum verticillatum X Myriophyllum sibiricum X X X X Najas flexilis X X a X Nelumbo lutea X Nymphaea

  16. A Probability Co-Kriging Model to Account for Reporting Bias and Recognize Areas at High Risk for Zebra Mussels and Eurasian Watermilfoil Invasions in Minnesota

    Directory of Open Access Journals (Sweden)

    Kaushi S. T. Kanankege

    2018-01-01

    Full Text Available Zebra mussels (ZMs (Dreissena polymorpha and Eurasian watermilfoil (EWM (Myriophyllum spicatum are aggressive aquatic invasive species posing a conservation burden on Minnesota. Recognizing areas at high risk for invasion is a prerequisite for the implementation of risk-based prevention and mitigation management strategies. The early detection of invasion has been challenging, due in part to the imperfect observation process of invasions including the absence of a surveillance program, reliance on public reporting, and limited resource availability, which results in reporting bias. To predict the areas at high risk for invasions, while accounting for underreporting, we combined network analysis and probability co-kriging to estimate the risk of ZM and EWM invasions. We used network analysis to generate a waterbody-specific variable representing boater traffic, a known high risk activity for human-mediated transportation of invasive species. In addition, co-kriging was used to estimate the probability of species introduction, using waterbody-specific variables. A co-kriging model containing distance to the nearest ZM infested location, boater traffic, and road access was used to recognize the areas at high risk for ZM invasions (AUC = 0.78. The EWM co-kriging model included distance to the nearest EWM infested location, boater traffic, and connectivity to infested waterbodies (AUC = 0.76. Results suggested that, by 2015, nearly 20% of the waterbodies in Minnesota were at high risk of ZM (12.45% or EWM (12.43% invasions, whereas only 125/18,411 (0.67% and 304/18,411 (1.65% are currently infested, respectively. Prediction methods presented here can support decisions related to solving the problems of imperfect detection, which subsequently improve the early detection of biological invasions.

  17. Environmental Assessment for Extension of Wastewater Treatment Plant Effluent Force Main and Discharge to Wateree River for Shaw Air Force Base, South Carolina

    Science.gov (United States)

    2004-12-01

    canadensis Black duck Anas reburpes Bobcat Lynx rufus Cotton mouse Peromyscus gossypinus Eastern chipmunk Tamia striatus Eastern cottontail Sylvilagus...philoxeroides Brazilian elodea Egeria densa Common reed Phragmites communis Eurasian watermilfoil Myriophyllum spicatum Giant salvinia Salvinia molesta

  18. Importance of nutrient competition and allelopathic effects in suppression of the green alga Scenedesmus obliquus by the macrophytes Chara, Elodea and Myriophyllum

    NARCIS (Netherlands)

    Lürling, M.; Van Geest, G.J.; Scheffer, M.

    2006-01-01

    Possible allelopathic effects of substances released from the macrophytes Chara globularis, Elodea canadensis, Myriophyllum spicatum on the common green alga Scenedesmus obliquus were tested in the laboratory with plastic plants and untreated medium as controls. A two-phase approach was used in

  19. Chemical composition and in vitro anti-algal activity of Potamogeton crispus and Myriophyllum spicatum extracts

    National Research Council Canada - National Science Library

    Haroon, Amany M; Abdel-Aal, Eman I

    2016-01-01

    .... Organic solvents differed in polarity including petroleum ether, methylene chloride, chloroform, acetone and methanol were used to extract the phytochemical compounds and gas chromatograph–mass spectrometry (GC–MS...

  20. Evading Invasives: How Eurasian Water-Milfoil Effects the Development of Lakefront Properties

    OpenAIRE

    Goodenberger, James; Klaiber, H. Allen

    2013-01-01

    Eurasian water-milfoil is an aquatic invasive plant that has moved rapidly through lakes across the United States. Along with being a hazard to local ecosystems, water-milfoil is a nuisance to those who use lakes for recreation, and its presence even lowers the value of lakefront properties. Though its effects can cause great disutility to lake users, no empirical studies have emerged that investigate the impacts that Eurasian water-milfoil, or any other invasive species, have on human behavi...

  1. Point Intercept and Surface Observation GPS (SOG): A Comparison of Survey Methods - Lake Gaston, NC/VA

    Science.gov (United States)

    2008-11-01

    and exhibited low diversity, domi- nated by coontail (Ceratophyllum demersum L.) and muskgrass (Chara spp.), but included traces of a naiad ( Najas ...giant lyngbya N 0.2 0.6 Myriophyllum spicatum Eurasian watermilfoil E 0.3 0.8 Najas guadalupensis southern naiad N 0.5 1.5 Nelumbo lutea American...were observed mixed with hydrilla. Naiads (either southern naiad and/or the exotic brittle naiad, Najas minor All.) were also found in mixed

  2. Uso de diferentes herbicidas no controle de Myriophyllum aquaticum Chemical Control of Myriophyllum aquaticum

    Directory of Open Access Journals (Sweden)

    E. Negrisoli

    2003-01-01

    Full Text Available Este estudo teve a finalidade de avaliar, em condições de caixa d'água, o controle químico de Myriophyllum aquaticum (pinheiro-d'água, através de herbicidas aplicados em pós-emergência. Os herbicidas e respectivas doses (g ha-1 foram: diquat (Reward a 204 g i.a. ha-1; diquat a 102 e 204 g i.a. ha-1 + Agral a 0,1%; 2,4-D (DMA 806 BR a 167, 335, 670 e 1.340 g e.a. ha-1; glyphosate (Rodeo a 3.360 g e.a. ha-1 + Aterbane a 0,5%; e imazapyr (Arsenal a 250 g e.a. ha-1. As parcelas foram constituídas por caixas d'água de 0,60 x 0,60 x 0,45 m, com 120 litros de água + 20 litros de solo e 20 ramos por caixa. Utilizou-se um pulverizador costal a pressão constante de CO2 a 2 bar, pontas 110.02 VS, com um consumo de calda de 180 l ha-1. O controle foi avaliado visualmente aos 2, 6, 9,11, 13, 17, 20, 23, 26, 30 e 36 dias após a aplicação dos herbicidas (DAAH. Inicialmente, o herbicida diquat foi o composto que apresentou os sintomas mais severos de intoxicação nos ramos de pinheiro-d'água aos 2 DAAH, com 65% de controle em média, e aos 20 DAAH ele atingiu o controle máximo (99%, porém ocorreram rebrotas a partir dos 23 DAAH, independentemente da adição ou não de Agral e das doses testadas. O herbicida 2,4-D proporcionou 100% de controle dos ramos a partir dos 23 DAAH para as doses de 1.340 e 670 g ha-1, não ocorrendo rebrotas; já para as demais doses testadas (335 e 167 g ha-1 o controle não foi eficiente, pois ocorreram rebrotas. Os herbicidas glyphosate e imazapyr não foram eficientes no controle desta espécie.This work was carried out at the Advanced Weed Research Nucleus - UNESP, Botucatu-SP, to evaluate the control of Myriophyllum aquaticum by applying different herbicides in post emergence. The herbicides and doses (g ha-1 tested were: diquat (Reward at 204 g a.i. ha-1, diquat at 102 and 204 g a.i. ha-1 + agral at 0.1% v/v; 2,4-D (DMA 806 BR at 1,340, 670, 335 and 167 g a.e. ha-1; glyphosate (Rodeo at 3.360 g a.e. ha-1

  3. Methylobacterium gnaphalii sp. nov., isolated from leaves of Gnaphalium spicatum.

    Science.gov (United States)

    Tani, Akio; Sahin, Nurettin; Kimbara, Kazuhide

    2012-11-01

    A pink-pigmented, facultatively methylotrophic bacterium, strain 23e(T), was isolated from the leaves of Gnaphalium spicatum (cudweed). The cells of strain 23e(T) were Gram-reaction negative, motile and non-spore-forming rods. On the basis of 16S rRNA gene sequence similarities, strain 23e(T) was related to Methylobacterium organophilum ATCC 27886(T) (97.1%) and Methylobacterium marchantiae JT1(T) (97%), and the phylogenetic similarities to all other Methylobacterium species with validly published names were less than 97%. Major cellular fatty acids were C(18:1)ω7c, C(16:00) and C(18:0). The results of DNA-DNA hybridization, phylogenetic analyses based on 16S rRNA and cpn60 gene sequences, fatty acid profiles, whole-cell matrix-assisted laser desorption/ionization time of flight/MS analysis, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain 23e(T) from the phylogenetically closest relatives. We propose that strain 23e(T) represents a novel species within the genus Methylobacterium, for which the name Methylobacterium gnaphalii sp. nov. is proposed. The type strain is 23e(T) (=DSM 24027(T)=NBRC 107716(T)).

  4. Selective Control of Eurasian Watermilfoil in Houghton Lake, Michigan: 2002-2006

    Science.gov (United States)

    2012-07-01

    Name Submersed Plants Bladderwort Utricularia vulgaris Coontail Ceratophyllum demersum Elodea Elodea canadensis Alpine pondweed Potamogeton...difficult or impossible to boat, swim, water ski , or fish in Eurasian watermilfoil-dominated areas. Interference with recrea- tion can result in a reduction

  5. Combinations of Endothall With 2,4-D and Triclopyr for Eurasian Watermilfoil Control

    Science.gov (United States)

    2010-04-01

    L., K. D. Getsinger, and A. B. Stewart. 1998. Selective effects of aquatic herbicides on sago pondweed. J. Aquat. Plant Manage. 36:64-68. Sprecher...Westerdahl, H. E., and J. F. Hall. 1983. Threshold 2,4-D concentrations for control of Eurasian watermilfoil and sago pondweed. J. Aquat. Plant

  6. Evaluation of a New Biological Control Pathogen for Management of Eurasian Watermilfoil

    Science.gov (United States)

    2013-06-01

    reducing biodiversity . Its ability to grow at low temperatures allows it to quickly reach the water surface, forming a canopy that shades out other...Aquatic Plant Management Society. Gunner, H. B. 1983. Microbial control of Eurasian watermilfoil. Miscellaneous Paper A-83-4. Vicksburg, MS: U.S

  7. The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community

    NARCIS (Netherlands)

    Wendt-Rasch, L.; Brink, van den P.J.; Crum, S.J.H.; Woin, P.

    2004-01-01

    The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated

  8. Myriophyllum aquaticum Constructed Wetland Effectively Removes Nitrogen in Swine Wastewater

    Directory of Open Access Journals (Sweden)

    Haishu Sun

    2017-10-01

    Full Text Available Removal of nitrogen (N is a critical aspect in the functioning of constructed wetlands (CWs, and the N treatment in CWs depends largely on the presence and activity of macrophytes and microorganisms. However, the effects of plants on microorganisms responsible for N removal are poorly understood. In this study, a three-stage surface flow CW was constructed in a pilot-scale within monospecies stands of Myriophyllum aquaticum to treat swine wastewater. Steady-state conditions were achieved throughout the 600-day operating period, and a high (98.3% average ammonia removal efficiency under a N loading rate of 9 kg ha-1 d-1 was observed. To determine whether this high efficiency was associated with the performance of active microbes, the abundance, structure, and interactions of microbial community were compared in the unvegetated and vegetated samples. Real-time quantitative polymerase chain reactions showed the abundances of nitrifying genes (archaeal and bacterial amoA and denitrifying genes (nirS, nirK, and nosZ were increased significantly by M. aquaticum in the sediments, and the strongest effects were observed for the archaeal amoA (218-fold and nirS genes (4620-fold. High-throughput sequencing of microbial 16S rRNA gene amplicons showed that M. aquaticum greatly changed the microbial community, and ammonium oxidizers (Nitrosospira and Nitrososphaera, nitrite-oxidizing bacteria (Nitrospira, and abundant denitrifiers including Rhodoplanes, Bradyrhizobium, and Hyphomicrobium, were enriched significantly in the sediments. The results of a canonical correspondence analysis and Mantle tests indicated that M. aquaticum may shift the sediment microbial community by changing the sediment chemical properties. The enriched nitrifiers and denitrifiers were distributed widely in the vegetated sediments, showing positive ecological associations among themselves and other bacteria based on phylogenetic molecular ecological networks.

  9. Expanded Simulation Models Version 3.0 for Growth of the Submerged Aquatic Plants American Wildcelery, Sago Pondweed, Hydrilla, and Eurasian Watermilfoil

    Science.gov (United States)

    2007-11-01

    Sago Pondweed, Hydrilla, Eurasian Watermilfoil by Elly P. H. Best and William A. Boyd PURPOSE: This technical note describes modifications of...Wildcelery, Sago Pondweed, Hydrilla, and Eurasian Watermilfoil 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...monoecious Potamogeton pectinatus1 ( sago pondweed)-POTAM (Best and Boyd 1996, 1999a, 1999b, 2001a, 2001b, 2003a, 2003b, Boyd and Best 1996). These models can

  10. Selective Control of Eurasian Watermilfoil and Curlyleaf Pondweed in Noxon Rapids Reservoir, Montana: Aquatic Herbicide Evaluations, 2009-2010

    Science.gov (United States)

    2013-04-01

    indicates that reductions in Plot 1 were due to the herbicide application and not natural senescence. Eurasian watermilfoil was found during the 5- and 52...Plot 4 indicates that reductions in Plot 3 were due to the herbicide application and not natural senescence. Similar to other plots, curlyleaf...Army Engineer Research and Development Center. ERDC/EL TR-13-5 80 Skogerboe, J. G., A. G. Poovey, K. D. Getsinger, W. Crowell, and E. Macbeth

  11. Ratios of species abundance to invasive Submerged Aquatic Vegetation (SAV) Eurasian milfoil, Myriophyllum spicatum in the Mobile Tensaw Delta, northern Gulf of Mexico in July - October, 2006 (NODC Accession 0200021)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are spreadsheet data which are a subset of thesis data for the Degree of Doctorate of Philosophy in Marine Science. The objectives of the study are to...

  12. 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

  13. Allelopathic Effects of Myriophyllum aquaticum on Two Cyanobacteria of Anabaena flos-aquae and Microcystis aeruginosa.

    Science.gov (United States)

    Wang, Haiping; Liu, Feng; Luo, Pei; Li, Zihan; Zheng, Liguo; Wang, Hua; Zou, Dongsheng; Wu, Jinshui

    2017-04-01

    Allelopathy has been proposed as a sustainable means to control undesired algal growth and to reduce blooms threatening freshwater systems worldwide. In this study, the allelopathic effects of Myriophyllum aquaticum and its exudate on two typical bloom-forming cyanobacteria, Microcystis aeruginosa and Anabaena flos-aquae, were investigated under laboratory conditions. The growth of the cyanobacteria was strongly inhibited by live M. aquaticum while the primary addition of M. Aquaticum exudates had a significant inhibitory effect on the growth of M. aeruginosa but not A. flos-aquae. The results suggested that the persistent release of allelochemicals from live M. aquaticum was needed to effectively constrain the growth of A. flos-aquae. Analysis of cyanobacterial physiological indexes indicated that M. aquaticum produced an inhibitory effect on SOD enzyme activity of A. flos-aquae, while it affected membrane lipid peroxidation in M. aeruginosa. The results show the potential of M. aquaticum to mitigate cyanobacterial blooms in coexistence systems.

  14. Effects of a mixture of tetracyclines to Lemna gibba and Myriophyllum sibiricum evaluated in aquatic microcosms

    Energy Technology Data Exchange (ETDEWEB)

    Brain, Richard A. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada)]. E-mail: rbrain01@uoguelph.ca; Wilson, Christian J. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Johnson, David J. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Sanderson, Hans [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Bestari, Ketut [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Hanson, Mark L. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Sibley, Paul K. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Solomon, Keith R. [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada)

    2005-12-15

    The impact of a mixture of oxytetracycline, chlortetracycline, tetracycline and doxycycline on Myriophyllum sibiricum and Lemna gibba was investigated using fifteen 12,000-L microcosms (k = 5, n = 3). Significant concentration-response relationships were only found for M. sibiricum, where dry mass was 69, 47, 30, and 7% of controls at respective treatment concentrations of 0.080, 0.218, 0.668, and 2.289 {mu}mol/L. Somatic endpoints were strongly and negatively correlated with percent light transmission, except plant length, which was positively correlated. Treated microcosms experienced a reduction in the percent of surface irradiance penetrating the water column as high as 99.8% at a depth of 70 cm, relative to controls. Position relative to the water column was likely responsible for the differential effects observed between floating (L. gibba) and submerged (M. sibiricum) species of macrophytes. A hazard quotient assessment of the lowest EC{sub 10} value indicated significant risk, exceeding the critical HQ value, but not the lowest EC{sub 25} value. - Mixtures of tetracycline antibiotics pose a risk to submerged but not floating aquatic plants.

  15. Effects of live Myriophyllum aquaticum and its straw on cadmium accumulation in Nasturtium officinale.

    Science.gov (United States)

    Huang, Kewen; Lin, Lijin; Chen, Fabo; Liao, Ming'an; Wang, Jin; Tang, Yi; Lai, Yunsong; Liang, Dong; Xia, Hui; Wang, Xun; Ren, Wei

    2017-10-01

    The purpose of this study is to determine whether the allelopathy of living Myriophyllum aquaticum and its straw has the same effects; two pot experiments were conducted to study the effects of intercropping using M. aquaticum and its straw on the growth and cadmium (Cd) accumulation of Nasturtium officinale. Different planting ratios (1:3, 2:2 and 3:1) of N. officinale and M. aquaticum led to an increase in the biomass of both plant species and increased the Cd content in roots and shoots of N. officinale, but led to a reduction in the Cd content in roots and shoots of M. aquaticum. When the intercropping ratio of N. officinale and M. aquaticum was 3:1, the Cd amount in whole plants reached the maximum of 293.96 μg pot-1. Mulching the straw of M. aquaticum roots on the soil surface increased the biomass of N. officinale, but mulching the straw of M. aquaticum stems and leaves led to a decrease. Mulching the straw of roots, stems and leaves of M. aquaticum reduced Cd content and amounts in roots and shoots of N. officinale. Intercropping with M. aquaticum can improve the Cd uptake ability of N. officinale, but mulching M. aquaticum straw can reduce its Cd uptake ability.

  16. Actividad citotóxica del extracto etanólico de gnaphalium spicatum "keto keto" en cultivos de líneas celulares tumorales humanas

    Directory of Open Access Journals (Sweden)

    David Callacondo-Riva

    2008-10-01

    Full Text Available Objetivos. Evaluar la actividad citotóxica de extractos etanólicos de raíces, tallos, hojas y flores de Gnaphalium spicatum sobre algunas líneas celulares tumorales humanas. Materiales y métodos. Las líneas celulares HT-29, H-460, MCF-7, M-14, PC-3, DU-145, K-562, y 3T3, fueron expuestas a cuatro concentraciones de extractos etanólicos de raíces, tallos, hojas y flores de Gnaphalim spicatum, asimismo, a diferentes concentraciones de cisplatino, que se usó como control positivo. Se halló los porcentajes de crecimiento en 48 horas. Luego se determinó la concentración inhibitoria 50 (CI50 mediante análisis de regresión lineal, el índice de selectividad de cada muestra y finalmente, la relación dosis-respuesta entre las concentraciones de los extractos y cisplatino, con los porcentajes de crecimiento. Resultados. El extracto etanólico de las raíces de Gnaphalium spicatum mostró mayor actividad citotóxica en la líneas celulares MCF-7 y K-562. Los CI50 en μg/mL fueron de 98 (r= -0,98 p a 0,250 mg/mL en todas la líneas celulares evaluadas. Conclusiones. Los extractos etanólicos de tallos, hojas y flores de Gnaphalium spicatum no mostraron actividad citotóxica en este bioensayo. Los extractos de raíces mostraron citotoxicidad en las todas las líneas celulares tumorales, excepto en M-14. Además fueron menos citotóxicos en relación al cisplatino en la línea celular 3T3.

  17. Habitat differentiation of the Myriophyllum altemiflorum and Littorella uniflora phytocoenoses in Poland

    Directory of Open Access Journals (Sweden)

    Stanisław Kłosowski

    2011-01-01

    Full Text Available The present study showed the ecological differentiation of phytocoenoses dominated either by Myriophyllum alterniflorum or by Littorella uniflora, which in Poland are classified within the Myriophylletum alterniflori or Myriophyllo-Littorelletum association. The properties which best differentiated the waters of the above types of phytocoenoses were calcium and factors associated with the carbonate complex (pH, electrolytic conductivity, total and carbonate hardness, and pH in the case of substrates. The most distinct differences in the habitats were found between the phytocoenoses dominated by L. uniflora from the Pomeranian Lobelia lakes and those dominated by M. alterniflorum from the Łęczna-Włodawa Lake District, in which other species from the Littorelletea uniflorae class were absent. The L. uniflora phytocoenoses are associated with soft waters poor in Ca2+ and with the lowest values of pH, electrolytic conductivity, dissolved organic matter (COD-KMnO4 and dissolved SiO2. The substrates they inhabit are mineral and more acidic. By contrast, the values of the above-mentioned properties are considerably higher in the case of the phytocoenoses from the Łęczna-Włodawa Lake District. The habitats of the M. alterniflorum phytocoenoses from the Pomeranian Lobelia lakes occupy an intermediate position and are more similar to those of M. alterniflorum from the Łęczna-Włodawa Lake District. The results obtained in this study suggest that the phytocoenoses of L. uniflora and M. alterniflorum should not be included in the same association. Further studies are, therefore, necessary to resolve this problem. The comparative analysis of the present ecological findings and data obtained from other regions of Europe show that in Poland the phytocoenoses dominated either by L. uniflora or by M. alterniflorum, in which the contribution of Littorelletea uniflorae species is appreciable, are clearly associated with soft waters and their habitats are

  18. Effects of Elevated [CO2] and Low Soil Moisture on the Physiological Responses of Mountain Maple (Acer spicatum L.) Seedlings to Light

    OpenAIRE

    Gabriel Danyagri; Qing-Lai Dang

    2013-01-01

    Global climate change is expected to affect how plants respond to their physical and biological environments. In this study, we examined the effects of elevated CO2 ([CO2]) and low soil moisture on the physiological responses of mountain maple (Acer spicatum L.) seedlings to light availability. The seedlings were grown at ambient (392 µmol mol(-1)) and elevated (784 µmol mol(-1)) [CO2], low and high soil moisture (M) regimes, at high light (100%) and low light (30%) in the greenhouse for one ...

  19. JPEG Images of chirp subbottom profiler data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (JPEG Image Format)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  20. JPEG images of bottom samples collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (JPEG Images)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  1. Locations of bottom photographs collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_PHOTOS.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  2. Unique shot point navigation for Edgetech SB-424 chirp subbottom profiler data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_CHIRPSHT.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  3. Klein 3000 sidescan-sonar survey lines collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire by the U.S. Geological Survey in 2005 (Geographic, WGS 84, Esri Polyline Shapefile, 2005-004-FA_SONARTRK).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  4. Survey tracklines of swath bathymetry collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri polyline shapefile, 2005-004-FA_BATHYTRK.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  5. 1-meter swath bathymetric grid collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (UTM Zone 19N, WGS 84, Esri Binary Grid, WINNI_BATHY)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  6. Text files of the Wide Area Augmentation System (WAAS) navigation collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, HYPACK ASCII Text Files)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  7. Sediment sample and textural properties at 40 sample locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_SAMPLES.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  8. Trackline navigation for video data from 40 sample locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri polyline shapefile, 2005-004-FA_VIDEOTRK.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  9. Sound velocity profile locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_SVP.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  10. Survey tracklines of chirp subbottom data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri polyline shapefile, CHIRP_TRK.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  11. 1-meter per pixel sidescan-sonar mosaic collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire by the U.S. Geological Survey in 2005 (GeoTIFF, UTM Zone 19N, WGS 84, WINNI_SONAR.TIF)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once...

  12. Application of a new sediment contact test with Myriophyllum aquaticum and of the Aquatic Lemna test to assess the sediment quality of Lake Skadar

    Energy Technology Data Exchange (ETDEWEB)

    Stesevic, D.; Sundic, D.; Mijovic, S. [Montenegro Univ., Podgorica (ME). Faculty of Sciences; Feiler, U.; Heininger, P. [Federal Institute of Hydrology, Koblenz (Germany); Erdinger, L. [Heidelberg Univ. (Germany). Inst. of Hygiene; Seiler, T.B.; Hollert, H. [Heidelberg Univ. (Germany). Dept. of Zoology; RWTH Aachen (Germany). Inst. fuer Umweltforschung - Biologie V

    2007-10-15

    Goal, Scope and Background: Situated in the transboundary belt between Montenegro and Albania, the Lake Skadar is the largest freshwater reservoir in Southeastern Europe. Because of the wide range of endemic, rare or endangered plant and animal species it supports, Lake Skadar and its extensive adjacent wetlands are internationally recognised as a site of significance and importance (Ramsar site). Within the last 10 to 20 years, Lake Skadar was exposed to intensive pollution. For the assessment of the ecotoxic load of the sediments sampled in Lake Skadar, a triad approach was recently applied. Overall, a complex spectrum of ecotoxic loads was elucidated. The aim of the present study was to use plant-based bioassays for assessing the sediment quality of Lake Skadar in order to facilitate and complement the triad test battery. The newly developed sediment contact test with Myriophyllum aquaticum and the aquatic growth inhibition test with Lemna minor were applied to native sediments and pore water, respectively, allowing the investigation of different toxicity-effects caused by particle-bound pollutants as well as pollutants in the interstitial water. This investigation is the first application of the novel sediment contact test with Myriophyllum aquaticum to lake sediments. Materials and Methods: Sediment samples were taken from nine selected sites at Lake Skadar and investigated by the sediment contact assay with Myriophyllum aquaticum. The pore water was extracted from these sediment samples to be analysed in the aquatic growth inhibition test with Lemna minor. The results of the sediment contact tests were compared with each other and with those of the aquatic growth inhibition test. Results and Discussion: Both applied macrophyte biotests revealed distinct changes in the growth behaviour of the two macrophytes subsequent to the exposure to the investigated natural sediments of Lake Skadar. The Myriophyllum sediment contact test revealed significant toxicity in

  13. Growth, morphology, ammonium uptake and nutrient allocation of Myriophyllum brasiliense Cambess. under high NH₄⁺ concentrations.

    Science.gov (United States)

    Saunkaew, Piyanart; Wangpakapattanawong, Prasit; Jampeetong, Arunothai

    2011-11-01

    The effects of high NH(4)(+) concentration on growth, morphology, NH(4) (+) uptake and nutrient allocation of Myriophyllum brasiliense were investigated in hydroponic culture. The plants were grown under greenhouse conditions for 4 weeks using four levels of NH(4)(+) concentration: 1, 5, 10 and 15 mM. M. brasiliense grew well with a relative growth rate of c.0.03 day(-1) at NH(4)(+) concentration up to 5 mM. At the higher NH(4)(+) concentrations the growth of the plants was stunted and the plants had short roots and few new buds, especially when grown in 15 mM NH(4)(+) where the submerged leaves were lost and there were rotten roots and submerged stems. To avoid NH(4)(+) toxicity, the plants may have a mechanism to prevent cytoplasmic NH(4)(+) accumulation in plant cells. The net uptake of NH(4)(+) significantly decreased and the total N significantly increased in the plants treated with 10 and 15 mM NH(4)(+), respectively. The plant may employ NH(4)(+) assimilation and extrusion as a mechanism to compensate for the high NH(4)(+) concentrations. However, the plants may show nutrient deficiency symptoms, especially K deficiency symptoms, after they were exposed to NH(4)(+) concentration higher than 10 mM. The present study provides a basic ecophysiology of M. brasiliense that it can grow in NH(4)(+) enriched water up to concentrations as high as 5 mM.

  14. Discrimination of Species and Hybrid Detection in Myriophyllum Spp.: an Introduction to Biodiversity Conservation and Invasion Avoidance

    Directory of Open Access Journals (Sweden)

    R Ghahramanzadeh

    2014-03-01

    Full Text Available Minimizing economical loss through introduction of invasive alien species (IAS in local ecosystem is one of the most important issues in biosecurity. The hybridization potential between non-indigenous and native species has raised concerns due mainly to introgression, which can cause extirpation of native species through gene contamination. In the present study, 71 samples belonging to 12 species from Myriophyllum genus were assessed in Plant Breeding group of Wageningen University. Internal transcribed spacer (ITS was used for identification of invasive species from related native and possible hybrid plants. The result showed that based on universal application, high sequence divergence and species discrimination, ITS is a powerful sequence for the identification of invasive species from related non-invasive foreign and native species. In contrast to morphological data, ITS grouped suspected hybrid plants in to M. heterophyllum and demonstrated that they have not resulted from hybridization. These observations suggest that multiple introduction and genetic recombination among different introduced genotypes or genetic pools could be reasons of non-flowering in suspected hybrid plants. Results showed that molecular markers enable to distinguish invasive plant species from their most closely related congeners. This could be helpful with enforcing a ban on important of such invasive which can help to plant ecosystem and biodiversity stability.

  15. Effects of herbicides on two submersed aquatic macrophytes, Potamogeton pectinatus L. and Myriophyllum sibiricum Komarov, in a prairie wetland.

    Science.gov (United States)

    Forsyth, D J; Martin, P A; Shaw, G G

    1997-01-01

    Clopyralid, picloram, 2,4-D and a mixture of 2,4-D plus picloram, (Tordon 202C) were added to the water of 1 m square enclosures in a prairie wetland in Saskatchewan, Canada to produce concentrations of 0.01 and 0.1 mg active ingredient litre(-1). Effects on the submersed macrophytes, Potamogeton pectinatus and Myriophyllum sibiricum, were monitored by taking repeated measurements of plant weight, flower and tuber production and inspecting for injuries at 30 and 60 days after application. Clopyralid did not inhibit weight gain (growth) in either species, but stimulated growth and flowering by M. sibiricum at 0.01 mg litre(-1) and tuber production by P. pectinatus at both rates. The low rate of 2,4-D stimulated flowering by M. sibiricum and tuber production by P. pectinatus, whereas the high rate inhibited growth of M. sibiricum and injured both species. Picloram did not affect growth of either species, but injured M. sibiricum at both concentrations and inhibited flowering at 0.1 mg litre(-1). Tordon 202C at 0.1 mg litre(-1) caused reduced growth and flowering in M. sibiricum and injured both species; 0.01 mg litre(-1) also injured M. sibiricum. Mortality resulted only from Tordon 202C and 2,4-D. Field data are lacking to assess the extent to which submerged macrophytes in prairie ponds are exposed to harmful concentrations of herbicide from aerial spraying, drift from ground application, runoff or wind erosion of soil.

  16. Phytoremediation potential of Myriophyllum aquaticum and Pistia stratiotes to modify antibiotic growth promoters, tetracycline, and oxytetracycline, in aqueous wastewater systems.

    Science.gov (United States)

    Gujarathi, Ninad P; Haney, Bryan J; Linden, James C

    2005-01-01

    Antibiotics are frequently used in the United States as feed efficiency promoters and medicines for livestock that is destined for human consumption. These antibiotics are released into the environment through the runoff and wastewater streams from animal feedlots and land applications of manure. The exposure of microorganisms to these antibiotics has reportedly resulted in the development of resistant species of microorganisms, which in turn can lead to human health hazards. Phytoremediation of these antibiotics can be a useful tool for countering this problem. Aquatic plants, Myriophyllum aquaticum (parrot feather) and Pistia stratiotes (water lettuce), were used for studying phytoremediation of tetracycline (TC) and oxytetracycline (OTC) from aqueous media. TC and OTC are two of the most commonly used tetracyclines in veterinary medicine. M. aquaticum and P. stratiotes gave high antibiotic modification rates of both antibiotics. Kinetic analyses dismiss direct enzyme catalysis; the modification rates decreased with increasing OTC concentrations. Sterile, cell-free root exudates (filtered through 0.2 microm membranes) from both species also exhibited comparable antibiotic modification rates. The involvement of root-secreted metabolites in antibiotic modification is suggested. The changes in the UV absorbance spectra of OTC during treatment with the root exudates confirmed the modification.

  17. Nitrogen removal in Myriophyllum aquaticum wetland microcosms for swine wastewater treatment: 15 N-labelled nitrogen mass balance analysis.

    Science.gov (United States)

    Zhang, Shunan; Liu, Feng; Xiao, Runlin; He, Yang; Wu, Jinshui

    2017-01-01

    Ecological treatments are effective for treating agricultural wastewater. In this study, wetland microcosms vegetated with Myriophyllum aquaticum were designed for nitrogen (N) removal from two strengths of swine wastewater, and 15 N-labelled ammonium (NH4+ -N) was added to evaluate the dominant NH4+ -N removal pathway. The results showed that 98.8% of NH4+ -N and 88.3% of TN (TN: 248.6 mg L-1 ) were removed from low-strength swine wastewater (SW1) after an incubation of 21 days, with corresponding values for high-strength swine wastewater (SW2) being 99.2% of NH4+ -N and 87.8% of TN (TN: 494.9 mg L-1 ). Plant uptake and soil adsorption respectively accounted for 24.0% and 15.6% of the added 15 N. Meanwhile, above-ground tissues of M. aquaticum had significantly higher biomass and TN content than below-ground (P wetlands for high N-loaded animal wastewater treatment. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Efeito do cobre na atividade da enzima pirogalol peroxidase em plantas de Myriophyllum aquaticum cultivadas em solução nutritiva Effect of copper on the activity of pirogalol peroxidase in Myriophyllum aquaticum plants cultivated in nutritives solution

    Directory of Open Access Journals (Sweden)

    V.D. Domingos

    2005-06-01

    Full Text Available Myriophyllum aquaticum é uma planta perene, herbácea, que pode se desenvolver totalmente submersa ou com a porção terminal dos ramos acima da superfície da água. É também considerada uma planta daninha que possui elevado potencial de colonização, o qual, dependendo da densidade populacional, pode causar aumento no teor de matéria orgânica e redução de oxigênio na água, comprometendo a qualidade da água e seus usos múltiplos. O objetivo do presente trabalho foi verificar a influência do cobre na atividade da pirogalol peroxidase de plantas de M. aquaticum submetidas à solução nutritiva contendo concentrações de cobre de 1,2; 11,2; 21,2; 31,2; e 41,2 µg L-1. O experimento foi conduzido em um delineamento experimental inteiramente casualizado, com quatro repetições e cinco tratamentos, aos quais as plantas foram submetidas durante 21 dias. Aos 81 dias após a instalação das mudas em solução nutritiva contendo os diferentes níveis de cobre, as folhas foram colhidas a partir do ápice da planta até o final do ramo, que não estavam em contato com a solução. Esse material fresco foi envolvido por plástico transparente e papel-alumínio e, a seguir, congelado em nitrogênio líquido, sendo armazenado em freezer a -20 ºC até o momento da determinação da atividade da enzima pirogalol peroxidase. A atividade da enzima foi progressiva com o aumento das doses de cobre. As plantas cultivadas com 40 µg L-1 de Cu2+ após três semanas, com base em avaliação visual, apresentaram redução no desenvolvimento.Myriophyllum aquaticum is a perennial, herbaceous plant which grows totally submerged or with the terminal portion of the branches above the surface of the water. It is also considered to be a harmful plant, possessing a high colonization potential which, depending on population density, can increase the organic matter content and reduce oxygen in the water, compromising the quality of water and its multiple uses

  19. The adaptability of a wetland plant species Myriophyllum aquaticum to different nitrogen forms and nitrogen removal efficiency in constructed wetlands.

    Science.gov (United States)

    Wang, Rui; Bai, Na; Xu, Shengjun; Zhuang, Guoqiang; Bai, Zhihui; Zhao, Zhirui; Zhuang, Xuliang

    2017-12-30

    Constructed wetlands (CWs) cultivated with Myriophyllum aquaticum showed great potential for total nitrogen (TN) removal from aquatic ecosystems in previous studies. To evaluate the growth characteristics, photosynthetic pigment content, and antioxidative responses of M. aquaticum, as well as its TN removal efficiency in CWs, M. aquaticum was treated with different levels of ammonium (NH4+) and nitrate (NO3-) for 28 days. The results indicated that M. aquaticum had strong nitrogen stress tolerance and was more likely to be suppressed by high levels of NH4+ than NO3-. High levels of NH4+ also led to inhibition of synthesis of photosynthetic pigments and increased peroxidase activity in plant leaves, which was not found in the NO3- treatments. High levels of both NH4+ and NO3- generated obvious oxidative stress through elevation of malondialdehyde content while decreasing superoxide dismutase activity in the early stage. A sustainable increase of TN removal efficiency in most of the CWs indicated that M. aquaticum was a candidate species for treating wastewater with high levels of nitrogen because of its higher tolerance for NH4+ and NO3- stress. However, the increase of TN removal efficiency was hindered in the late stage when treated with high levels of NH4+ of 26 and 36 mmol/L, indicating that its tolerance to NH4+ stress might have a threshold. The results of this study will enrich the studies on detoxification of high ammonium ion content in NH4+-tolerant submerged plants and supply valuable reference data for proper vegetation of M. aquaticum in CWs.

  20. Composition and in vitro cytotoxic activities of essential oil of Hedychium spicatum from different geographical regions of western Himalaya by principal components analysis.

    Science.gov (United States)

    Mishra, Tripti; Pal, Mahesh; Meena, Sanjeev; Datta, Dipak; Dixit, Prateek; Kumar, Anil; Meena, Baleshwar; Rana, T S; Upreti, D K

    2016-01-01

    The rhizome of Hedychium spicatum has been widely used in traditional medicines. The present study deals with the evaluation of the cytotoxic potential of rhizome essential oils from four different regions of the Western Himalaya (India) along with comparative correlation analysis to characterise the bioactive cytotoxic component. The essential oils were coded as MHS-1, MHS-2, MHS-3 and MHS-4, and characterised using GC-FID and GC-MS. The main volatile compounds identified were 1,8-cineol, eudesmol, cubenol, spathulenol and α-cadinol. In vitro cytotoxic activities were assessed against human cancer cell lines such as, the lung (A549), colon (DLD-1, SW 620), breast (MCF-7, MDA-MB-231), head and neck (FaDu), and cervix (HeLa). MHS-4 is significantly active in comparison to other samples against all cancer cell lines. Sample MHS-4 has major proportion of monoterpene alcohol mainly 1,8-cineol. Principal components analysis was performed for the experimental results and all four samples were clustered according to their percentage inhibition at different doses.

  1. Potamogeton x sparganiifolius (Zwaardfonteinkruid) in de duinen gevonden

    NARCIS (Netherlands)

    Bruin, Kees (C.) J.W.

    2002-01-01

    The rare hybrid Potamogeton x sparganiifolius (P. natans x gramineus) was discovered in a dune lake on the isle of Texel. It grows in shallow water with both parents, accompanied by Myriophyllum spicatum and Chara aspera.

  2. Alocação de biomassa e nutrientes em Myriophyllum aquaticum sob diferentes níveis de macronutrientes Allocation of biomass and nutrients in Myriophyllum aquaticum at different levels of macronutrient

    Directory of Open Access Journals (Sweden)

    V.D. Domingos

    2005-06-01

    Full Text Available O objetivo deste trabalho foi verificar o efeito de diferentes concentrações de macronutrientes no crescimento e na alocação de biomassa seca em folha, caule e raiz de Myriophyllulm aquaticum. As plantas foram cultivadas em vasos plásticos preenchidos com areia lavada e emersas em solução nutritiva. O experimento foi conduzido em um delineamento inteiramente ao acaso, com quatro níveis (0, 25, 50 e 75% da concentração original de N, P, K Ca, Mg e S da solução nutritiva, além de uma testemunha (100% da solução nutritiva, com quatro repetições e por um período de 38 dias. A maior produção de biomassa total foi obtida na testemunha. A ausência de K afetou a alocação de biomassa em raízes. Quanto ao comprimento total dos ramos, a maior resposta ocorreu entre os níveis de Ca a 60 mg L-1. A solução a 100% dos macronutrientes propiciou o maior comprimento das plantas. O número de ramos entre os níveis de N e P seguiu uma tendência linear e crescente com as concentrações desses nutrientes, porém em maior proporção para o fósforo. As condições mais favoráveis ao desenvolvimento das plantas ocorreram a 100% dos macronutrientes da solução base. Entre os níveis de nitrogênio verificaram-se maiores teores de N nas folhas do que nos caules. Já para os demais nutrientes a alocação desses recursos foi destinada em maior proporção para o caule. A maior alocação de biomassa nesta espécie destinou-se ao caule.The objective of this work was to verify the effect of different macronutrient concentrations on plant growth and dry biomass allocation in leaves, stems and roots of Myriophyllum aquaticum. The plants were cultivated in plastic pots filled with washed sand and immersed in nutritive solution. The study was carried out in a randomized complete design with four levels of nutrition solution at 0, 25, 50, 75% from the original concentration solution of N, P, K Ca, Mg and S, besides a control (100% of the

  3. Effects of elevated [CO2] and low soil moisture on the physiological responses of Mountain Maple (Acer spicatum L. seedlings to light.

    Directory of Open Access Journals (Sweden)

    Gabriel Danyagri

    Full Text Available Global climate change is expected to affect how plants respond to their physical and biological environments. In this study, we examined the effects of elevated CO2 ([CO2] and low soil moisture on the physiological responses of mountain maple (Acer spicatum L. seedlings to light availability. The seedlings were grown at ambient (392 µmol mol(-1 and elevated (784 µmol mol(-1 [CO2], low and high soil moisture (M regimes, at high light (100% and low light (30% in the greenhouse for one growing season. We measured net photosynthesis (A, stomatal conductance (g s, instantaneous water use efficiency (IWUE, maximum rate of carboxylation (V cmax, rate of photosynthetic electron transport (J, triose phosphate utilization (TPU, leaf respiration (R d, light compensation point (LCP and mid-day shoot water potential (Ψx. A and g s did not show significant responses to light treatment in seedlings grown at low soil moisture treatment, but the high light significantly decreased the C i/C a in those seedlings. IWUE was significantly higher in the elevated compared with the ambient [CO2], and the effect was greater at high than the low light treatment. LCP did not respond to the soil moisture treatments when seedlings were grown in high light under both [CO2]. The low soil moisture significantly reduced Ψx but had no significant effect on the responses of other physiological traits to light or [CO2]. These results suggest that as the atmospheric [CO2] rises, the physiological performance of mountain maple seedlings in high light environments may be enhanced, particularly when soil moisture conditions are favourable.

  4. Effects of elevated [CO2] and low soil moisture on the physiological responses of Mountain Maple (Acer spicatum L.) seedlings to light.

    Science.gov (United States)

    Danyagri, Gabriel; Dang, Qing-Lai

    2013-01-01

    Global climate change is expected to affect how plants respond to their physical and biological environments. In this study, we examined the effects of elevated CO2 ([CO2]) and low soil moisture on the physiological responses of mountain maple (Acer spicatum L.) seedlings to light availability. The seedlings were grown at ambient (392 µmol mol(-1)) and elevated (784 µmol mol(-1)) [CO2], low and high soil moisture (M) regimes, at high light (100%) and low light (30%) in the greenhouse for one growing season. We measured net photosynthesis (A), stomatal conductance (g s), instantaneous water use efficiency (IWUE), maximum rate of carboxylation (V cmax), rate of photosynthetic electron transport (J), triose phosphate utilization (TPU)), leaf respiration (R d), light compensation point (LCP) and mid-day shoot water potential (Ψx). A and g s did not show significant responses to light treatment in seedlings grown at low soil moisture treatment, but the high light significantly decreased the C i/C a in those seedlings. IWUE was significantly higher in the elevated compared with the ambient [CO2], and the effect was greater at high than the low light treatment. LCP did not respond to the soil moisture treatments when seedlings were grown in high light under both [CO2]. The low soil moisture significantly reduced Ψx but had no significant effect on the responses of other physiological traits to light or [CO2]. These results suggest that as the atmospheric [CO2] rises, the physiological performance of mountain maple seedlings in high light environments may be enhanced, particularly when soil moisture conditions are favourable.

  5. Monitoring of heavy metal burden in mute swan (Cygnus olor).

    Science.gov (United States)

    Grúz, Adrienn; Szemerédy, Géza; Kormos, Éva; Budai, Péter; Majoros, Szilvia; Tompai, Eleonóra; Lehel, József

    2015-10-01

    Concentrations of heavy metals (especially arsenic, cadmium, chromium, copper, mercury and lead) were measured in the contour (body) feathers of mute swans (Cygnus olor) and in its nutrients (fragile stonewort [Chara globularis], clasping leaf pondweed [Potamogeton perfoliatus], Eurasian watermilfoil [Myriophyllum spicatum], fennel pondweed [Potamogeton pectinatus]) to investigate the accumulation of metals during the food chain. The samples (17 feathers, 8 plants) were collected at Keszthely Bay of Lake Balaton, Hungary. Dry ashing procedure was used for preparing of sample and the heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Copper (10.24 ± 2.25 mg/kg) and lead (1.11 ± 1.23 mg/kg) were detected the highest level in feathers, generally, the other metals were mostly under the detection limit (0.5 mg/kg). However, the concentrations of the arsenic (3.17 ± 1.87 mg/kg), cadmium (2.41 ± 0.66 mg/kg) and lead (2.42 ± 0.89 mg/kg) in the plants were low but the chromium (198.27 ± 102.21 mg/kg) was detected in high concentration.

  6. Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

    Science.gov (United States)

    Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

    2002-01-01

    Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

  7. Nanometer-scale elongation rate fluctuations in the Myriophyllum aquaticum (Parrot feather) stem were altered by radio-frequency electromagnetic radiation.

    Science.gov (United States)

    Senavirathna, Mudalige Don Hiranya Jayasanka; Asaeda, Takashi; Thilakarathne, Bodhipaksha Lalith Sanjaya; Kadono, Hirofumi

    2014-01-01

    The emission of radio-frequency electromagnetic radiation (EMR) by various wireless communication base stations has increased in recent years. While there is wide concern about the effects of EMR on humans and animals, the influence of EMR on plants is not well understood. In this study, we investigated the effect of EMR on the growth dynamics of Myriophyllum aquaticum (Parrot feather) by measuring the nanometric elongation rate fluctuation (NERF) using a statistical interferometry technique. Plants were exposed to 2 GHz EMR at a maximum of 1.42 Wm(-2) for 1 h. After continuous exposure to EMR, M. aquaticum plants exhibited a statistically significant 51 ± 16% reduction in NERF standard deviation. Temperature observations revealed that EMR exposure did not cause dielectric heating of the plants. Therefore, the reduced NERF was due to a non-thermal effect caused by EMR exposure. The alteration in NERF continued for at least 2.5 h after EMR exposure and no significant recovery was found in post-EMR NERF during the experimental period.

  8. Microbiological Control of Eurasian Watermilfoil

    Science.gov (United States)

    1990-06-01

    occurring endemic infestation. Two other pathogenic fungi, Fusarium sporotrichoides and Acre- monium curvulum, were also shown to be potent...t. Green bean (Phaseolus vulgaris), pea (Pisun satimw L.), vetch (Vicia sp.), and wheat (Triticum satiwn) plants were exposed to M. t. grown in PDSB...of Weeds," Aquatic Botany, Vol 3, No. 2, pp 111-123. Andrews, J. H., and Hecht, E. P. 1981. "Evidence of Pathogenicity of Fusarium sporotrichoides to

  9. A Survey of the Invasive Aquatic and Riparian Plants of the Low Rio Grande

    Science.gov (United States)

    2005-04-01

    watermilfoil E Submersed Phragmites australis (Cav.) Trin.ex Steud common reed ? Emergent Polygonum spp. smartweed N Emergent Pontederia cordata L...spicatum Below Del Rio 8/18/03 313582 323531 3245477 3238196 C. demersum H. dubia Hydrocotyle spp. Ludwigia spp. P. cordata Polygonum spp. P

  10. Effects of linuron on a rooted aquatic macrophyte in sediment-dosed test systems

    NARCIS (Netherlands)

    Buresova, H.; Crum, S.J.H.; Belgers, J.D.M.; Adriaanse, P.I.; Arts, G.H.P.

    2013-01-01

    Effects of linuron on the sediment-rooted aquatic macrophyte Myriophyllum spicatum L. were studied in sediment-dosed test systems following a proposed guideline with extended test duration. Sediment, pore water, overlying water and macrophyte shoots were sampled weekly for chemical analyses. Linuron

  11. Distribution and production of submerged macrophytes in Tipper Grund (Ringkøbing Fjord, Denmark), and the impact of waterfowl grazing

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    1980-01-01

    . at intermediate depth and Potamogeton pectinatus, Myriophyllum spicatum and Ranunculus baudauti at greater depth. (2) All macrophyte species showed a unimodal peak of biomass during the summer. Angiosperms with heavy epiphytic load withered 1-2 months earlier than did angiosperms without epiphytes. (3) Annual...

  12. 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

  13. Improvements in the use of aquatic herbicides and establishment of future research directions

    Science.gov (United States)

    Getsinger, K.D.; Netherland, M.D.; Grue, C.E.; Koschnick, T.J.

    2008-01-01

    Peer-reviewed literature over the past 20 years identifies significant changes and improvements in chemical control strategies used to manage nuisance submersed vegetation. The invasive exotic plants hydrilla (Hydrilla verticillata L.f. Royle) and Eurasian watermilfoil (Myriophyllum spicatum L.) continue to spread and remain the plant species of greatest concern for aquatic resource managers at the national scale. Emerging exotic weeds of regional concern such as egeria (Egeria densa Planch.), curlyleaf pondweed (Potamogeton crispus L.), and hygrophila (Hygrophila polysperma (Roxb.) T. Anders), as well as native plants such as variable watermilfoil (Myriophyllum heterophyllum Michx), and cabomba (Cabomba caroliniana Gray) are invasive outside their home ranges. In addition, there is always the threat of new plant introductions such as African elodea (Lagarosiphon major (Ridley) Moss) or narrow-leaf anacharis (Egeria najas Planchon). The registration of the bleaching herbicide fluridone in the mid 1980s for whole-lake and large-scale management stimulated numerous lines of research involving reduction of use rates, plant selectivity, residue monitoring, and impacts on fisheries. In addition to numerous advances, the specificity of fluridone for a single plant enzyme led to the first documented case of herbicide resistance in aquatic plant management. The resistance of hydrilla to fluridone has stimulated a renewed interest by industry and others in the registration of alternative modes of action for aquatic use. These newer chemistries tend to be enzyme-specific compounds with favorable non-target toxicity profiles. Registration efforts have been facilitated by increased cooperation between key federal government agencies that have aquatic weed control and research responsibilities, and regulators within the U.S. Environmental Protection Agency (USEPA). We reviewed past and current research efforts to identify areas in need of further investigation and to establish

  14. Remote sensing of California estuaries: Monitoring climate change and invasive species

    Science.gov (United States)

    Mulitsch, Melinda Jennifer

    The spread of invasive species and climate change are among the most serious global environmental threats. The goal of this dissertation was to link inter-annual climate change and biological invasions at a landscape scale using novel remote sensing techniques applied to the San Francisco Bay/Sacramento- San Joaquin Delta Estuary. I evaluated the use of hyperspectral imagery for detecting invasive aquatic species in the Delta using 3 m HyMap hyperspectral imagery. The target invasive aquatics weeds were the emergent water hyacinth (Eichhornia crassipes) and the submerged Brazilian waterweed (Egeria densa). Data were analyzed using linear spectral mixture analysis (SMA). The results show the weeds were mapped with a classification accuracy of 90.6% compared to 2003 sample sites and 82.6% accuracy compared to 2004 sample sites. Brazilian waterweed locations were successfully mapped but the abundances were overestimated because we did not separate it from other submerged aquatic vegatation (SAV). I evaluated 3 m HyMap imagery, from 2004, for SAV species in the Delta, including: Brazilian waterweed ( Egeria densa), Eurasian watermilfoil (Myriophyllum spicatum ), curlyleaf pondweed (Potamogeton crispus), coontail (Ceratophyllum demersum), American pondweed (Potamogeton nodosus), fanwort (Cabomba caroliniana), and common elodea (Elodea canadensis). Data were analyzed using SMA with a classification accuracy of 84.4%. Spectral simulations of Brazilian waterweed and American pondweed show how spectral properties can change at different water depths and varying water quality. Finally I address the effect of inter-annual climate change on the estuary ecology in the San Francisco Bay by analyzing current (2002) and historical (1994-1996) Airborne Visible Infrared Imaging Spectrometer (AVIRIS) datasets to map salt marsh species distribution. The species in the estuary, Salicornia virginica, Spartinia foliosa, Scirpus robustus, and Distichlis spicata undergo dramatic changes in

  15. Possible allelopathic effects of cyanotoxins, with reference to microcystin-LR, in aquatic ecosystems.

    Science.gov (United States)

    Pflugmacher, Stephan

    2002-01-01

    During recent years a shift from macrophyte-dominated to more phytoplankton-dominated lakes has been correlated to the process of eutrophication. The existence of numerous substances exhibiting allelopathic effects on the growth of algae has been shown in different aquatic macrophytes (e.g., Myriophyllum spicatum) and is thought to be an important mechanism in stabilizing the macrophyte-dominated clear-water state of a lake. A few recent studies have shown that algae themselves can produce special substances inhibiting growth or photosynthetic processes in other algae. A well-known cyanobacterial secondary metabolite, microcystin-LR, was tested for its allelopathic power on aquatic macrophytes such as Ceratophyllum demersum and Myriophyllum spicatum, resulting in growth inhibition, reduction in photosynthetic oxygen production, and changes in pigment pattern. This shows that microcystin-LR has a possible role as an allelopathic infochemical. Copyright 2002 Wiley Periodicals, Inc.

  16. Aportaciones a la flora de Galicia, VIII

    OpenAIRE

    Gómez Vigide, F.; García Martínez, X.R.; Silva Pando, F.J.; González Domínguez, J.; Blanco Dios, J.B.; Rodríguez González, A.; Rial Pousa, S.; Álvarez Graña, D.; Caamaño Portela, J.L.; Pino Pérez, J.J.; Pino Pérez, R.

    2006-01-01

    Se citan 37 plantas de variado interés para la flora gallega. Se incluyen 8 novedades de carácter regional (Pteris incompleta Cav., Potentilla recta L., Myriophyllum spicatum L., Solanum sisymbrifolium Lam., Knautia integrifolia (L.) Bertol., Senecio inaequidens DC. Melica arrecta G. Kunze y Stipa clausa Trab.), 17 novedades provinciales (Vandenboschia speciosa (Willd.) G. Kunkel, Ranunculus bupleuroides Brot., Silene niceensis All., Armeria transmontana (Samp.) Lawr., Alcea rosea...

  17. Efficacité des méthodes de lutte contre le développement de cinq espèces de plantes invasives amphibies : Crassula helmsii, Hydrocotyle ranunculoides, Ludwigia grandiflora, Ludwigia peploides et Myriophyllum aquaticum (synthèse bibliographique

    Directory of Open Access Journals (Sweden)

    Delbart, E.

    2013-01-01

    Full Text Available Effectiveness of techniques used to control the development of five invasive amphibious plant species: Crassula helmsii, Hydrocotyle ranunculoides, Ludwigia grandiflora, Ludwigia peploides and Myriophyllum aquaticum. A review. Among rapidly spreading invasive species in Europe, amphibious plants are particularly problematic. These plants are capable of developing a photosynthetic activity both below and above the water surface, and they typically form dense floating populations. Controlling amphibious plants, whether for the purposes of total eradication or for the regulation of their spread, represents an important challenge for managers. A literature review of existing control methods for Crassula helmsii, Hydrocotyle ranunculoides, Ludwigia grandiflora, Ludwigia peploides and Myriophyllum aquaticu was carried out, taking into account efficiency and costs. Of the 87 studies analyzed, a great variation was evident in the research efforts undertaken (number and spatial scale of studies between species and between control methods. However, overall, the different control methods described showed a similar level of efficiency between species. Reports of total eradication of amphibious plants were rare. Such cases resulted from the application of mechanical or chemical methods, most often coupled with complementary methods such as manual finishing. The use of chemical control methods (less laborious and costly than others was found to be frequently documented in the literature. However, except in the case of some active substances, such chemical methods were found to provide low control efficiency. Similarly, to date, biological control has not been found to provide convincing results. In addition, it should be noted that several biological control agents are considered as invasive species in Europe. On the other hand, although little related research has been carried out, methods such as manual or mechanical removal with manual finishing have often

  18. 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.

  19. Phytotoxicity of atrazine, isoproturon, and diuron to submersed macrophytes in outdoor mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Knauert, Stefanie, E-mail: stefanie.knauert@basf.co [University of Basel, Department of Environmental Sciences, Hebelstrasse 1, 4056 Basel (Switzerland); Singer, Heinz; Hollender, Juliane [Eawag: Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Chemistry, Uberlandstrasse 133, 8600 Duebendorf (Switzerland); Knauer, Katja [University of Basel, Program Sustainability Research, Klingelbergstr. 50, 4056 Basel (Switzerland)

    2010-01-15

    The submersed macrophytes Elodea canadensis, Myriophyllum spicatum and Potamogeton lucens were constantly exposed over a five-week period to environmentally relevant concentrations of atrazine, isoproturon, diuron, and their mixture in outdoor mesocosms. Effects were evaluated investigating photosynthetic efficiency (PE) of the three macrophytes and growth of M. spicatum and E. canadensis. Adverse effects on PE were observed on days 2 and 5 after application. M. spicatum was found to be the more sensitive macrophyte. E. canadensis and P. lucens were less sensitive to atrazine, diuron and the mixture and insensitive to isoproturon. PE of M. spicatum was similarly affected by the single herbicides and the mixture demonstrating concentration addition. Growth of E. canadensis and M. spicatum was not reduced indicating that herbicide exposure did not impair plant development. Although PE measurements turned out to be a sensitive method to monitor PSII herbicides, plant growth remains the more relevant ecological endpoint in risk assessment. - Short-term effects on photosynthesis did not result in growth reduction of submerse macrophytes exposed to PSII inhibitors.

  20. Investigation of Two Insect Species for Control of Eurasian Watermilfoil.

    Science.gov (United States)

    1981-02-01

    alligatorweed (Alternanthera philoxeroides (Martius) Grisebach) (3); fanwort (Cabomba caroliniana Gray) (3); slender spikerush (Eleocharis...Southern naiad and Illinois pondweed were especially damaged. Only minor feeding occurred on creeping water primrose, watercress, and fanwort

  1. 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

  2. Management of Eurasian Watermilfoil in the Columbia River Basin.

    Science.gov (United States)

    1984-12-01

    Metabolism of Selected Submersed Freshwater Macrophytes," Ecolog- ical Monographs, Vol 51, No. 2, pp 219-235. 1982. "Ecology of Submersed Macrophytes...11X Fenac X Fluridone X X X Glyphosate X X x Simazine x Xylene X 2,4-D X x X Chemical-Adjuvants (Trade Names) Asgrow 403 inverting oil X X X Big Sur

  3. Reproductive Allocation in Three Macrophyte Species from Different Lakes with Variable Eutrophic Conditions.

    Directory of Open Access Journals (Sweden)

    Tao Wan

    Full Text Available Reproductive allocation is a key process in the plant life cycle and aquatic plants exhibit great diversity in their reproductive systems. In the present study, we conduct a field investigation of three aquatic macrophytes: Stuckenia pectinata, Myriophyllum spicatum, and Potamogeton perfoliatus. Our results showed that widespread species, including S. pectinata and M. spicatum had greater plasticity in their allocation patterns in the form of increased sexual and asexual reproduction, and greater potential to set seeds and increase fitness in more eutrophic environments. P. perfoliatus also exhibited a capacity to adopt varied sexual reproductive strategies such as setting more offspring for the future, although only in clear conditions with low nutrient levels. Our results establish strategies and mechanisms of some species for tolerating and surviving in varied eutrophic lake conditions.

  4. 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.

  5. Assessment of ecosystem response to a temporary water level drawdown and subsequent refilling at Topock Marsh, Arizona—July 2011–October 2014

    Science.gov (United States)

    Daniels, Joan S.; Haegele, Jeanette C.

    2017-01-20

    with higher concentrations of these components downstream (measured at TP-8). The upstream sampling locations in 2013–14 had decreased turbidity, therefore more SAV biomass accumulated, especially in shallow areas with water depths of ≤1.0 meter (≤3.3 feet). However, the furthest downstream station had higher turbidity caused by both the suspension of autochthonous sediment and high phytoplankton density and biovolume. This higher turbidity resulted in minimal SAV growth, especially in the deeper water (>1.0 meter [>3.3 feet]). Emergent vegetation not only survived the low water conditions of 2011, but expanded its areal coverage and subsequently thrived in the higher water elevations. Overall, no immediate critically negative consequences were detected for aquatic fauna or flora that could be attributd unequivocally to the effect of low water levels. Concentrations of nutrient and trace elements in all water samples were below wildlife toxicity thresholds as established by Arizona Department of Environmental Quality. Three nonnative species were discovered shortly after the Fire Break Canal went into operation. Of the three, gizzard shad (Dorosoma cepedianum) and Eurasian watermilfoil (Myriophyllum spicatum) increased substantially in numbers from 2011–14, but quagga mussels (Dreissena bugensis) did not increase. Future monitoring will determine the long-term impact of the new flow regime

  6. Suitability of aquatic biomass from Lake Toba (North Sumatra, Indonesia) for energy generation by combustion process

    Science.gov (United States)

    Brunerová, A.; Roubík, H.; Herák, D.

    2017-09-01

    Several aquatic plant species were identified as aquatic pollution of Lake Toba, North Sumatra (Indonesia); specifically, water hyacinth Eichhornia crassipes and aquatic weeds Hydrilla verticillata and Myriophyllum spicatum due to their high biomass yield which causes impenetrable mats at the bottom and surface of the lake. That complicates other vegetation growth and utilization of water areas for fishing or recreation. In attempt to clean the lake and prevent plants expansion, great amount of plants populations are removed from water but subsequent efficient utilization of such aquatic biomass is not ensured. Present research investigated energy potential of aquatic biomass originated from mentioned aquatic plants from Lake Toba and its possible utilization for energy production by direct combustion. Performed chemical analysis contained from determination of moisture, ash and volatile matter contents and calorific values. Evaluation of results proved highest suitability and energy potential of Eichhornia crassipes with gross calorific value (GCV) 16.31 MJ·kg-1, followed by Hydrilla verticillata with GCV 15.24 MJ·kg-1. Samples of Myriophyllum spicatum exhibited unsatisfactory results due to its low GCV (11.27 MJ·kg-1) in combination with high ash content (36.99%) which indicates complications during combustion, thus, low energy production efficiency and overall unsuitability for combustion purposes.

  7. Epiphytic bacterial community composition on two common submerged macrophytes in brackish water and freshwater.

    Science.gov (United States)

    Hempel, Melanie; Blume, Maja; Blindow, Irmgard; Gross, Elisabeth M

    2008-04-10

    Plants and their heterotrophic bacterial biofilm communities possibly strongly interact, especially in aquatic systems. We aimed to ascertain whether different macrophytes or their habitats determine bacterial community composition. We compared the composition of epiphytic bacteria on two common aquatic macrophytes, the macroalga Chara aspera Willd. and the angiosperm Myriophyllum spicatum L., in two habitats, freshwater (Lake Constance) and brackish water (Schaproder Bodden), using fluorescence in situ hybridization. The bacterial community composition was analysed based on habitat, plant species, and plant part. The bacterial abundance was higher on plants from brackish water [5.3 x 10(7) cells (g dry mass)-1] than on plants from freshwater [1.3 x 10(7) cells (g dry mass)-1], with older shoots having a higher abundance. The organic content of freshwater plants was lower than that of brackish water plants (35 vs. 58%), and lower in C. aspera than in M. spicatum (41 vs. 52%). The content of nutrients, chlorophyll, total phenolic compounds, and anthocyanin differed in the plants and habitats. Especially the content of total phenolic compounds and anthocyanin was higher in M. spicatum, and in general higher in the freshwater than in the brackish water habitat. Members of the Cytophaga-Flavobacteria-Bacteroidetes group were abundant in all samples (5-35% of the total cell counts) and were especially dominant in M. spicatum samples. Alphaproteobacteria were the second major group (3-17% of the total cell counts). Betaproteobacteria, gammaproteobacteria, and actinomycetes were present in all samples (5 or 10% of the total cell counts). Planctomycetes were almost absent on M. spicatum in freshwater, but present on C. aspera in freshwater and on both plants in brackish water. Bacterial biofilm communities on the surface of aquatic plants might be influenced by the host plant and environmental factors. Distinct plant species, plant part and habitat specific differences in

  8. Growth rate, protein:RNA ratio and stoichiometric homeostasis of submerged macrophytes under eutrophication stress

    Directory of Open Access Journals (Sweden)

    Xing W.

    2016-01-01

    Full Text Available Growth rate hypothesis (GRH and stoichiometric homeostasis of photoautotrophs have always been questioned. However, little is known about GRH and stoichiometric homeostasis of aquatic plants, especially submerged macrophytes. Therefore, we aim to test the GRH and explore stoichiometric homeostasis of four freshwater submerged macrophytes under eutrophication stress. At the single species level and the multi-species level, N:P ratios of Potamogeton maackianus, Myriophyllum spicatum, Vallisneria natans and Ceratophyllum demersum had no consistent trends with growth rates. However, protein:RNA ratios of P. maackianus, M. spicatum and V. natans all correlated negatively with growth rates, demonstrating GRH can apply to freshwater submerged macrophytes, even though they are threatening by eutrophication stress. Protein:RNA ratios positively correlated with N:P ratios in culture media and tissues in submerged macrophytes except in P. maackianus (30d, suggesting effects of varying N:P ratios in culture media on protein:RNA ratios are basically in concert with tissue N:P ratios under short-time eutrophication stress. Stoichiometric homeostasis coefficients (HN:P indicated submerged macrophytes have weak homeostasis. Stoichiometric homeostasis of V. natans was stronger than those of P. maackianus, M. spicatum and C. demersum. The differences in GRH and homeostasis of the four submerged macrophytes may be due to species traits.

  9. Evaluation of Eurasian Watermilfoil Control Techniques Using Aquatic Herbicides in Fort Peck Lake, Montana

    Science.gov (United States)

    2015-07-01

    plots treated with endothall. Triclopyr: For waters treated with triclopyr (Kraken), there are no restrictions on swimming, fishing, livestock ...water tracing and can be monitored and quantified in-situ using a portable fluorometer (or analyzer with an appropriate sensor ). Several studies have

  10. Senescence as a Factor in Latent Pathogen Infection in Eurasian Watermilfoil

    Science.gov (United States)

    2009-09-01

    forests. In The Biodiversity of Fungi: Their Role in Human Life, ed. S. K. Dashmukh and M. K. Raj, 49-68. Enfield, NH: Science Publishers. Carroll, G...parasitic fungi. Can. J. Bot. 70:2089-2096. Stone, J. K., C. W. Bacon, and J. F. White, Jr. 2000. An overview of endophytic microbes : Endophytism

  11. Regeneration and growth rates of allofragments in four common stream plants

    DEFF Research Database (Denmark)

    Riis, Tenna; Madsen, Tom Vindbæk; Sennels, R. S. H.

    2009-01-01

    Colonisation by stream plants occurs to a large extent from simple stem fragments. Allofragments are stem fragments formed by mechanical breakage. We studied regeneration, colonisation, and growth rates in four common stream plants: Elodea canadensis Michx., Myriophyllum spicatum L., Potamogeton...... perfoliatus L. and Ranunculus baudotii x pseudofluitans. The objectives of this study were to determine (1) if shoots with an apical tip have higher regeneration (growth of new shoots and rhizomes from allofragments) and colonisation (root attachment in sediment) abilities and higher relative growth rates...... (RGR) than shoots without an apical tip, and (2) if fragment size correlates with regeneration and colonisation abilities and with RGR of fragments. For all species, over 60% of fragments regenerated new shoots and colonised. Apical shoots and larger fragments generally had higher regeneration...

  12. Accumulation of heavy metals and its effect on organic components of higher hydrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Ledl, G.

    1981-11-08

    The first part of this dissertation relates to field studies on rivers in Austria and North England. Water and plant samples were taken from various sites and tested for Fe, Mn, Zn, Cu, Ni, and Cd content using atomic absorption spectro-photometry. The second part deals with laboratory investigations. The mode of uptake of specific heavy metals in plants was briefly examined in short-term and long-term investigations. Three macrophytic organisms were selected for study, namely Myriophyllum spicatum, Potamogeton coloratus and Potamogeton pectinatus, together with the elements Cu, Cd and Ni. Finally, quantitative changes were measured in four groups of substances present in plants (sugar, starch, organic anions and amino acids) following the action of Cu, Cd and Ni for varying time periods.

  13. Macrophyte distribution and ecological status of the Turiec River (Slovakia: Changes after seven years

    Directory of Open Access Journals (Sweden)

    Hrivnák R.

    2009-01-01

    Full Text Available Characteristics of diversity, abundance, distribution, and ecological status of aquatic macrophytes were observed in 2000 and 2007 on a circa 4.5 km long section of the Turiec River using Kohler's method. In comparison to 2000, the total number of macrophytes in 2007 increased markedly (from 25 to 35, although only the numbers of amphi­phytes and helophytes were changed substantially. The number of hydrophytes increased from 11 to 12; an invasive, Elodea canadenis, was the only new species. The relative plant mass of hydrophytes represents the bulk of all recorded species (95 and 80% in 2000 and 2007, respectively, and it was changed for most hydrophytes. The most significant changes were detected for Myriophyllum spicatum (decrease, filamentous algae (decrease, and Potamogeton crispus (increase. In 2007, the mean mass total (MMT sum of hydrophytes decreased from 16.46 to 14.5. On the other hand, the MMTsum of amphiphytes and helophytes doubled in value (7.4 and 14.1 in 2000 and 2007, respectively. Within hydrophytes, Batrachium species (including B. aquatile and B. trichophyllum, Myriophyllum spicatum, and Potamogeton crispus were ubiquitous (distribution ratio d > 0.5 in 2000, whereas in 2007 only Batrachium species and Potamogeton crispus were ubiquitous. At all times, Batrachium species were the most frequent species in the study area, and their abundance was relatively high (MMT> 2.5. A poor ecological status (MMP = 0.378 and MMP = 0.333 in 2000 and 2007, respectively of the surveyed river section was found in both years, but a slight decline of quality as determined on the basis of aquatic plants was observed after 7 years.

  14. 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.

  15. Assessing the dietary sources of two cichlid species in River Nile sub-branches: Stomach contents, fatty acids and stable isotopes analyses

    Directory of Open Access Journals (Sweden)

    Mohamad S. Abd El-Karim

    2016-06-01

    Full Text Available We assess the importance of four different food sources as dietary components of Oreochromis niloticus and Sarotherodon galilaeus in Nile sub-branches using stomach contents, fatty acids (FA and stable isotopes (SI analyses. Diatoms were the dominant food items, whereas sand and mud constitute a major part of the stomach contents of both cichlids in the northern ElBehery canal. FAs and SI were compared in cichlids and four potential food sources. Carbon isotopes excluded the fresh macrophyte Myriophyllum spicatum and its epiphytes as a potential food source, whereas FA biomarkers indicated that M. spicatum is assimilated in cichlids’ muscles as detrital materials. FA profiles of cichlids’ muscles were highly enriched by live diatom markers whereas decayed diatoms and bacterial markers were partially present. Carbon isotope signatures of cichlids were much close to that of suspended particulate organic matter (SPOM which elucidated that SPOM was the source of diatoms and bacterial detritus incorporated in cichlids muscles. Cichlids were highly enriched with nitrogen signatures which was a result of increased anthropogenic effects and incorporation of bacterial films. SI and FA analyses precisely indicated that live diatoms and bacteria, detrital macrophytes are the main sources of organic matter incorporated in cichlids muscles.

  16. Biochemical adaptations of four submerged macrophytes under combined exposure to hypoxia and hydrogen sulphide.

    Directory of Open Access Journals (Sweden)

    Mahfuza Parveen

    Full Text Available A hydroponic experiment was performed to investigate the stress responses and biochemical adaptations of four submerged macrophytes, Potamogeton crispus, Myriophyllum spicatum, Egeria densa, and Potamogeton oxyphyllus, to the combined exposure of hypoxia and hydrogen sulfide (H2S, provided by NaHS. The investigated plants were subjected to a control, hypoxia, 0.1mM NaHS, 0.5 mM NaHS, 0.1 mM NaHS+hypoxia and 0.5 mM NaHS+hypoxia conditions. All experimental plants grew optimally under control, hypoxic and NaHS conditions in comparison to that grown in the combined exposure of hypoxia and hydrogen sulfide. For P. crispus and M. spicatum, significant decreases of total chlorophyll and increases in oxidative stress (measured by hydrogen peroxide, H2O2, and malondialdehyde, MDA were observed with exposure to both sulfide concentrations. However, the decrease in catalase (CAT and ascorbate peroxidase (APX from exposure to 0.5 mM NaHS suggests that the function of the protective enzymes reached their limit under these conditions. In contrast, for E. densa and P. oxyphyllus, the higher activities of the three antioxidative enzymes and their anaerobic respiration abilities (ADH activity resulted in higher tolerance and susceptibility under high sulfide concentrations.

  17. Morphological and biomechanical response to eutrophication and hydrodynamic stresses.

    Science.gov (United States)

    Zhu, Guorong; Yuan, Changbo; Di, Guilan; Zhang, Meng; Ni, Leyi; Cao, Te; Fang, Rongting; Wu, Gongguo

    2017-12-05

    Eutrophication and hydrodynamics determine the final distribution patterns of aquatic macrophytes; however, there is limited available knowledge regarding their interactive effects. Morphological and biomechanical responses to eutrophication and hydrodynamic stresses were assessed by sampling five abundant and dominant species, Potamogeton maackianus, P. pectinatus, P. lucens, Ceratophyllum demersum and Myriophyllum spicatum, in three macrophyte beds in Lake Erhai, Yunnan Province, China: one exposed to eutrophication and moderate southeast (SE) wind; one with mesotrophication, but sheltered by the lakeshore, with weak wind disturbance; and one with meso-eutrophication and strong SE wind. The results showed significant interactive effects of eutrophication and hydrodynamics on most biomechanical traits and some morphological traits, suggesting that aquatic macrophytes preferentially undergo biomechanical adjustments to resist the coexisting eutrophication and hydrodynamic stresses. In particular, hydrodynamics increased both the tensile force and tensile strain of P. maackianus under meso-eutrophication and dramatically decreased them in eutrophic areas, suggesting that eutrophication triggers mechanical failure in this species. Additionally, P. pectinatus, C. demersum and M. spicatum showed the lowest and highest values for the biomechanical variables (greater values for M. spicatum) in the most eutrophic and hydrodynamic areas, respectively, implying that increases in hydrodynamics primarily induce mechanical damage in eutrophic species. The plants generally exhibited greater tensile strain in both shallow and deep waters and the greatest tensile force at moderate depths. The stem cross-sectional area, plant height, stem length, internode length, and branch traits were all responsible for determining the biomechanical variables. This study reveals that hydrodynamic changes primarily induce mechanical damage in eutrophic species, whereas eutrophication triggers

  18. Changes in physico-chemical conditions and macrophyte abundance in a shallow soft-water lake mediated by a Great Cormorant roosting colony

    Directory of Open Access Journals (Sweden)

    Piotr Klimaszyk

    2014-08-01

    Full Text Available This study examined the effects of the Great Cormorant (Phalacrocorax carbo sinensis L. roosting colony on the physico-chemical conditions and macrophyte abundance in a shallow soft-water lobelia lake. We compared data collected in 1998 and 2009, before and after 9 years the establishment of a bird colony (2000 along the shoreline of the Lake Dołgie Wielkie (Poland, Europe. Additionally, soils and groundwater beneath the roosting colony were analyzed to evaluate the potential loads of nutrients conveyed to the lake through bird feces. Significant changes in the water quality of the lake were observed in terms of decreased water transparency, and increased conductivity, nitrogen, phosphorus and chlorophyll-a content. Abundance of the more sensitive macrophytes (Littorella uniflora and Myriophyllum alterniflorum also decreased. At the same time, the occurrence of new, typically meso- and eutrophic macrophytes such as Myriophyllum spicatum and C. demersum was recorded. Soils beneath the bird roosting area were characterized by over 100 fold higher concentrations of nitrogen and phosphorus comparing to not impacted littoral area. Increased nutrient content was also found in the groundwater below the bird colony. The present results suggest that the establishment of the Cormorants colony increases the trophic state of a soft-water lake and affects its macrophyte assemblages.

  19. Effects of 2,4-dichlorophenoxyacetic acid on Kentucky algae: simultaneous laboratory and field toxicity testings.

    Science.gov (United States)

    Kobraei, M E; White, D S

    1996-11-01

    2,4-D was applied to a cove in Kentucky Lake which was highly infested with Myriophllum spicatum (Eurasian watermilfoil). Effects of 2,4-D on nontarget algal communities were monitored concurrently in the field and in laboratory microcosms for eight days. Results indicated that indirect effects of water temperature and increased nutrient concentrations due to lysis in milfoil plants may be more important in the field community dominated by Chlorophyta, Pyrrhophyta, and Bacillariophyta. 2,4-D applied at the label-recommended rate of 2 mg/L or less stimulated total community growth in both laboratory and field indicating a possible hormonal effect of 2,4-D on algae. Reduced community growth and metabolism at high laboratory concentrations of 100 mg/L and 1000 mg/L may indicate an inhibitory effect on photosynthesis and/or respiration in algae. 2,4-D altered the laboratory community structure and function in all concentrations tested. Heterotrophic taxa such as Nitzschia, Euglena, Chlamydomonas, Mallomonas, Anabaena, and Oscillatoria appeared to be least affected by 2,4-D at high concentrations. Scenedesmus, Pediastrum, Characiosiphon, Navicula, Melosira, and Fragilaria appeared to be more sensitive, even in the lowest concentrations.

  20. 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.

  1. Aquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlands

    Science.gov (United States)

    Tang, Yingying; Harpenslager, Sarah F.; van Kempen, Monique M. L.; Verbaarschot, Evi J. H.; Loeffen, Laury M. J. M.; Roelofs, Jan G. M.; Smolders, Alfons J. P.; Lamers, Leon P. M.

    2017-02-01

    The sequestration of nutrients from surface waters by aquatic macrophytes and sediments provides an important service to both natural and constructed wetlands. While emergent species take up nutrients from the sediment, submerged and floating macrophytes filter nutrients directly from the surface water, which may be more efficient in constructed wetlands. It remains unclear, however, whether their efficiency is sufficient for wastewater purification and how plant species and nutrient loading affects nutrient distribution over plants, water and sediment. We therefore determined nutrient removal efficiencies of different vegetation (Azolla filiculoides, Ceratophyllum demersum and Myriophyllum spicatum) and sediment types (clay, peaty clay and peat) at three nutrient input rates, in a full factorial, outdoor mesocosm experiment. At low loading (0.43 mg P m-2 d-1), plant uptake was the main pathway (100 %) for phosphorus (P) removal, while sediments showed a net P release. A. filiculoides and M. spicatum showed the highest biomass production and could be harvested regularly for nutrient recycling, whereas C. demersum was outcompeted by spontaneously developing macrophytes and algae. Higher nutrient loading only stimulated A. filiculoides growth. At higher rates ( ≥ 21.4 mg P m-2 d-1), 50-90 % of added P ended up in sediments, with peat sediments becoming more easily saturated. For nitrogen (N), 45-90 % was either taken up by the sediment or lost to the atmosphere at loadings ≥ 62 mg N m-2 d-1. This shows that aquatic macrophytes can indeed function as an efficient nutrient filter but only for low loading rates (polishing) and not for high rates (purification). The outcome of this controlled study not only contributes to our understanding of nutrient dynamics in constructed wetlands but also shows the differential effects of wetland sediment types and plant species. Furthermore, the acquired knowledge may benefit the application of macrophyte harvesting to remove

  2. Foliar uptake of cesium from the water column by aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Pinder, J.E. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States); Hinton, T.G. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States)]. E-mail: thinton@srel.edu; Whicker, F.W. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1618 (United States)

    2006-07-01

    The probable occurrence and rate of foliar absorption of stable cesium ({sup 133}Cs) from the water column by aquatic macrophyte species was analyzed following the addition of {sup 133}Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (10{sup 3} L kg{sup -1} d{sup -1}) and a loss rate parameter k (d{sup -1}) were estimated for each species using time series of {sup 133}Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the {sup 133}Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u {>=} 0.75 x 10{sup 3} L kg{sup -1} d{sup -1}. Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for {sup 137}Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases.

  3. 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.

  4. 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

  5. Environmental state of aquatic systems in the Selenga River basin

    Science.gov (United States)

    Shinkareva, Galina; Lychagin, Mikhail

    2013-04-01

    a lesser extent Zn. Plant species which are the most important for the biomonitoring were identified: Phragmites australis, Ceratophyllum demersum, different pondweeds (Potamogeton pectinatus, Potamogeton crispus, Potamogeton friesii), Myriophyllum spicatum, Batrachium trichophyllum. Among them some species are characterized by a group concentration of heavy metals: pondweeds (Mn, Fe, Cu), Myriophyllum spicatum (Fe, Mn, Cu), Batrachium trichophyllum (Cu, Fe, Mn, Zn). Hornwort (Ceratophyllum demersum) is a concentrator of Mn.

  6. Native and non-native plants provide similar refuge to invertebrate prey, but less than artificial plants.

    Directory of Open Access Journals (Sweden)

    Bart M C Grutters

    Full Text Available Non-native species introductions are widespread and can affect ecosystem functioning by altering the structure of food webs. Invading plants often modify habitat structure, which may affect the suitability of vegetation as refuge and could thus impact predator-prey dynamics. Yet little is known about how the replacement of native by non-native vegetation affects predator-prey dynamics. We hypothesize that plant refuge provisioning depends on (1 the plant's native status, (2 plant structural complexity and morphology, (3 predator identity, and (4 prey identity, as well as that (5 structurally similar living and artificial plants provide similar refuge. We used aquatic communities as a model system and compared the refuge provided by plants to macroinvertebrates (Daphnia pulex, Gammarus pulex and damselfly larvae in three short-term laboratory predation experiments. Plant refuge provisioning differed between plant species, but was generally similar for native (Myriophyllum spicatum, Ceratophyllum demersum, Potamogeton perfoliatus and non-native plants (Vallisneria spiralis, Myriophyllum heterophyllum, Cabomba caroliniana. However, plant refuge provisioning to macroinvertebrate prey depended primarily on predator (mirror carp: Cyprinus carpio carpio and dragonfly larvae: Anax imperator and prey identity, while the effects of plant structural complexity were only minor. Contrary to living plants, artificial plant analogues did improve prey survival, particularly with increasing structural complexity and shoot density. As such, plant rigidity, which was high for artificial plants and one of the living plant species evaluated in this study (Ceratophyllum demersum, may interact with structural complexity to play a key role in refuge provisioning to specific prey (Gammarus pulex. Our results demonstrate that replacement of native by structurally similar non-native vegetation is unlikely to greatly affect predator-prey dynamics. We propose that

  7. Phytophilous Fauna of a Small and Artificial Urban Lake

    Directory of Open Access Journals (Sweden)

    Krajina Ivanka Orkić

    2017-06-01

    Full Text Available Phytophilous community on Myriophyllum spicatum was studied in a small artificial urban lake in the city of Osijek (eastern Croatia, during the spring and summer season in 2010. In the eutrophic conditions, macrophyte stands were well developed and in the formed periphyton representatives of the following invertebrate taxa were found: Hydrozoa, Nematoda, Gastropoda, Cladocera, Copepoda, Insecta larvae - including families Chironomidae and Coleoptera. They displayed differences in temporal abundance patterns. Two separate phases in macrophyte colonization with differences in invertebrate composition and abundance were recorded. Insect larvae, particularly Chironomidae, were most abundant in the first phase, through the spring period, and Hydra oligactis (brown hydra was most abundant in the second phase, i.e. summer period. Concurrently, microcrustacean abundance declined towards the end of the summer. Results of the analyses indicated that water temperature and perihyton biomass were the variables exerting the main influence on the invertebrate assemblage, while interestingly, macrophyte size and biomass were negatively correlated with most of the fauna abundance. On the other hand, brown hydra was negatively correlated with all other invertebrate taxa, except gastropods. Larger surface of submersed macrophytes is the main parameter supporting the increase of invertebrate abundance due to providing protection from predators and growth for periphyton, an important food source for these phytophilous organisms. Macrophyte length was positively correlated with Hydra abundance, while Chironomids were more influenced by periphyton biomass. These organisms can indicate water quality conditions and a potential increase in primary and secondary production.

  8. Flora of the Mediterranean Rivers in Bulgaria

    Directory of Open Access Journals (Sweden)

    Yordanka G. Hristeva

    2015-06-01

    Full Text Available Species composition and distribution of aquatic bryophytes and vascular plants assemblages in Mediteranean Rivers in Bulgaria are presented in this work. Aquatic macrophytes were studied at thirteen rivers in South Bulgaria during 2014, together with abiotic factors (flow velocity, shading, and substrate type, mean depth and altitude. In total, 73 species were registered, of them 13 bryophytes and 60 vascular plants were identified. Aquatic bryophytes included 10 mosses and 3 liverworts. The recorded bryophytes species refer to 7 families and 12 genera. The most frequently distributed species was Leptodictyum riparium (Hedw. Warnst., followed by Cratoneuron filicinum (Hedw. Spruce and Platyhypnidium riparioides (Hedw. Dixon, Brachythecium rivulare Schimp. and Hygroamblystegium tenax (Hedw. Jenn. The recorded 60 species of vascular plants refer to 25 families and 43 genera. The most common hydrophyte species was Lemna minor L., followed by Ranunculus trichophyllus Chaix, Myriophyllum spicatum L. and Potamogeton nodosus Poir. The most abundant species from the group of helophytes and amphiphytes was Mentha aquatica L., followed by Agrostis stolonifera L. Mentha spicata L., Berula erecta (Huds. Coville, Juncus effusus L., Lycopus europaeus L., Lythrum salicaria L., Phalaris arundinacea L., Ranunculus repens L., Sparganium erectum L., Typha latifolia L., and Veronica anagalis-aquatica L. The majority of studied rivers sites were sunny, with moderate velocity, stony bottom, average depth up to 0.3 m and altitude between 100 and 500 m a.s.l.

  9. Effects of surrounding land use on metal accumulation in environments and submerged plants in subtropical ponds.

    Science.gov (United States)

    Liu, Hui; Bu, Hongmei; Liu, Guihua; Wang, Zhixiu; Liu, Wenzhi

    2015-12-01

    Ponds are widely used as stormwater treatment facilities to retain contaminants, including metals, and to improve water quality throughout the world. However, there is still a limited understanding of the effects of surrounding land use on metal accumulation in pond environments and organisms. To address this gap, we measured the concentrations of nine metals (i.e., Al, Ba, Ca, K, Li, Mg, Na, Se, and Sr) in water, sediments, and submerged plants collected from 37 ponds with different surrounding land uses in southwestern China and assessed the metal accumulation capacity of four dominant submerged plant species. Our results showed that Al, Ca, and K concentrations in the water were above drinking water standards. In the sediments, the average concentrations of Ca and Sr were higher than the corresponding soil background values. Ceratophyllum demersum L. could accumulate more K in aboveground biomass than Myriophyllum spicatum L. and Potamogeton maackianus A. Benn. The K concentration in submerged plants was positively influenced by the corresponding metal concentration in the water and negatively influenced by water temperature. Among the nine studied metals, only the water K concentration in ponds receiving agricultural runoff was significantly higher than that for ponds receiving urban and forested runoff. This result suggests that surrounding land use types have no significant effect on metal accumulation in sediments and submerged plants in the studied ponds. A large percentage of the metals in these ponds may be derived from natural sources such as the weathering of rocks.

  10. Total mercury in sediments, macrophytes, and fish from a shallow steppe lake in eastern Austria.

    Science.gov (United States)

    Jirsa, Franz; Pirker, Daniel; Krachler, Regina; Keppler, Bernhard K

    2014-08-01

    During summer 2011, samples of sediment, macrophytes, and fish tissues from the shallow, slightly alkaline Lake Neusiedl, Austria, were evaluated for their total Hg content. This is the first report of Hg levels from this lake. Sediments displayed Hg contents between 0.025 and 0.113 μg g(-1) dw (dry weight), significantly correlating with the proportion of organic components pointing to a small anthropogenic impact on the lake's Hg content. Hg Levels in plants and fish were unexpectedly high: both investigated submerged plant species, Potamogeton pectinatus and Myriophyllum spicatum, showed mean values of 0.245 ± 0.152 and 0.298 ± 0.115 μg g(-1) dw, respectively. Biomagnification was evident when comparing muscle samples of the planktivorous fish species rudd Scardinus erythrophthalmus (n = 10, mean = 0.084 μg g(-1) ww (wet weight)) with the piscivorous perch Perca fluviatilis (n = 21, mean = 0.184 μg g(-1) ww) or pike-perch Sander lucioperca (n = 9, mean = 0.205 μg g(-1) ww). Significantly lower values were found in the muscle of the piscivorous pike Esox lucius (n = 25, mean = 0.135 μg g(-1) ww), pointing to a specific Hg metabolism of this fish, presumably under the particular physicochemical properties of the lake. Hg Concentrations in fish could pose a risk to piscivorous birds in this protected wetland system. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  11. Ciliate communities of a large shallow lake: association with macrophyte beds.

    Science.gov (United States)

    Karus, Katrit; Feldmann, Tõnu; Nõges, Peeter; Zingel, Priit

    2014-08-01

    We investigated the influence of macrophyte composition on ciliate community structure in a large, shallow, eutrophic Lake Võrtsjärv. We hypothesized that macrophyte composition must have strong influence on the dispersal of ecologically different ciliate groups in a shallow lake and that more diverse macrophyte stands cause also a greater diversity in the ciliate community. In Võrtsjärv macrophyte distribution is spatially strongly polarized both in east-west and north-south directions in relation to abiotic factors. Phragmites australis and Myriophyllum spicatum were the most widespread species occurring in most parts of the lake. Correlation of environmental, macrophyte and planktonic ciliate variables confirmed the suggested spatial gradients. More diverse macrophyte stands supported a high species richness and abundance of epiplanktonic community but showed negative influence on the number and abundance of euplanktonic ciliate taxa. Opposite trends were found relative to the abundance of P. australis. Benthic ciliates showed a similar distribution pattern to euplanktonic taxa being most abundant in sites were the Shannon-Weaver index for macrophytes was low. Strong polarizing effect of the lake's vegetation on planktonic ciliate diversity was reflected in correlations of the number of ciliate taxa as well as the numbers of eu- and epiplanktonic taxa with geographic co-ordinates. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2000: A stratified random approach

    Science.gov (United States)

    Carter, J.; Merino, J.H.; Merino, S.L.

    2009-01-01

    Estimates of submerged aquatic vegetative (SAV) along the U.S. Gulf of Mexico (Gulf) generally focus on seagrasses. In 2000, we attempted a synoptic survey of SAV in the mesohaline (5-20 ppt) zone of estuarine and nearshore areas of the northeastern Gulf. Areas with SAV were identified from existing aerial 1992 photography, and a literature review was used to select those areas that were likely to experience mesohaline conditions during the growing season. In 2000, a drought year, we visited 217 randomly selected SAV beds and collected data on species composition and environmental conditions. In general, sites were either clearly polyhaline (2: 20 ppt) or oligohaline (S 5 ppt), with only five sites measuring between 5 and 20 ppt. Ruppia maritima L. (13-35 ppt, n = 28) was the only species that occurred in mesohaline salinities. Halodule wrightii Asch. occurred in 73% of the beds. The nonindigenous Myriophyllum spicatum L. was present in four locations with salinities below 3 ppt. No nonindigenous macroalgae were identified, and no nonindigenous angiosperms occurred in salinities above 3 ppt. Selecting sample locations based on historical salinity data was not a successful strategy for surveying SAV in mesohaline systems, particularly during a drought year. Our ability to locate SAV beds within 50 m of their aerially located position 8 yr later demonstrates some SAV stability in the highly variable conditions of the study area. ?? 2009 by the Marine Environmental Silences Consortium of Alabama.

  13. Mapping species of submerged aquatic vegetation with multi-seasonal satellite images and considering life history information

    Science.gov (United States)

    Luo, Juhua; Duan, Hongtao; Ma, Ronghua; Jin, Xiuliang; Li, Fei; Hu, Weiping; Shi, Kun; Huang, Wenjiang

    2017-05-01

    Spatial information of the dominant species of submerged aquatic vegetation (SAV) is essential for restoration projects in eutrophic lakes, especially eutrophic Taihu Lake, China. Mapping the distribution of SAV species is very challenging and difficult using only multispectral satellite remote sensing. In this study, we proposed an approach to map the distribution of seven dominant species of SAV in Taihu Lake. Our approach involved information on the life histories of the seven SAV species and eight distribution maps of SAV from February to October. The life history information of the dominant SAV species was summarized from the literature and field surveys. Eight distribution maps of the SAV were extracted from eight 30 m HJ-CCD images from February to October in 2013 based on the classification tree models, and the overall classification accuracies for the SAV were greater than 80%. Finally, the spatial distribution of the SAV species in Taihu in 2013 was mapped using multilayer erasing approach. Based on validation, the overall classification accuracy for the seven species was 68.4%, and kappa was 0.6306, which suggests that larger differences in life histories between species can produce higher identification accuracies. The classification results show that Potamogeton malaianus was the most widely distributed species in Taihu Lake, followed by Myriophyllum spicatum, Potamogeton maackianus, Potamogeton crispus, Elodea nuttallii, Ceratophyllum demersum and Vallisneria spiralis. The information is useful for planning shallow-water habitat restoration projects.

  14. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2001 and 2002: A salinity gradient approach

    Science.gov (United States)

    Merino, J.H.; Carter, J.; Merino, S.L.

    2009-01-01

    Distribution of marine submerged aquatic vegetation (SAV; i.e., seagrass) in the northern Gulf of Mexico coast has been documented, but there are nonmarine submersed or SAV species occurring in estuarine salinities that have not been extensively reported. We sampled 276 SAV beds along the gulf coast in Florida, Alabama, Mississippi, Louisiana, and Texas in 2001 and 2002 in oligohaline to polyhaline (0 to 36 parts per thousand) waters to determine estuarine SAV species distribution and identify mesohaline SAV communities. A total of 20 SAV and algal species was identified and habitat characteristics such as salinity, water depth, pH, conductivity, turbidity, dissolved oxygen, and sediment composition were collected. Fourteen SAV species occurred two or more times in our samples. The most frequently occurring species was Ruppia maritima L. (n = 148), occurring in over half of SAV beds sampled. Eleocharis sp. (n = 47), characterized with an emergent rather than submerged growth form, was a common genus in the SAV beds sampled. A common marine species was Halodule wrightii Asch. (n = 36). Nonindigenous species Myriophyllum spicatum L. (n = 31) and Hydrilla verticillata (L. f.) Royle (n = 6) were present only in oligohaline water. Analyzing species occurrence and environmental characteristics using canonical correspondence and two-way indicator species analysis, we identify five species assemblages distinguished primarily by salinity and depth. Our survey increases awareness of nonmarine SAV as a natural resource in the gulf, and provides baseline data for future research. ?? 2009 by the Marine Environmental Sciences Consortium of Alabama.

  15. A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Vervliet-Scheebaum, Marco, E-mail: marco.vervliet@biologie.uni-freiburg.d [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Straus, Alain [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Tremp, Horst [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany); Hamer, Mick [Ecological Sciences, Syngenta Crop Protection AG, Jealott' s Hill International Research Centre, Bracknell, Berkshire RG42 6EY (United Kingdom); Maund, Stephen J. [Ecological Sciences, Syngenta Crop Protection AG, 4002 Basel (Switzerland); Wagner, Edgar [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Schulz, Ralf [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany)

    2010-02-15

    This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

  16. Metabolic Effect Level Index Links Multivariate Metabolic Fingerprints to Ecotoxicological Effect Assessment.

    Science.gov (United States)

    Riedl, Janet; Schreiber, René; Otto, Matthias; Heilmeier, Hermann; Altenburger, Rolf; Schmitt-Jansen, Mechthild

    2015-07-07

    A major goal of ecotoxicology is the prediction of adverse outcomes for populations from sensitive and early physiological responses. A snapshot of the physiological state of an organism can be provided by metabolic fingerprints. However, to inform chemical risk assessment, multivariate metabolic fingerprints need to be converted to readable end points suitable for effect estimation and comparison. The concentration- and time-dependent responsiveness of metabolic fingerprints to the PS-II inhibitor isoproturon was investigated by use of a Myriophyllum spicatum bioassay. Hydrophilic and lipophilic leaf extracts were analyzed with gas chromatography-mass spectrometry (GC-MS) and preprocessed with XCMS. Metabolic changes were aggregated in the quantitative metabolic effect level index (MELI), allowing effect estimation from Hill-based concentration-response models. Hereby, the most sensitive response on the concentration scale was revealed by the hydrophilic MELI, followed by photosynthetic efficiency and, 1 order of magnitude higher, by the lipophilic MELI and shoot length change. In the hydrophilic MELI, 50% change compares to 30% inhibition of photosynthetic efficiency and 10% inhibition of dry weight change, indicating effect development on different response levels. In conclusion, aggregated metabolic fingerprints provide quantitative estimates and span a broad response spectrum, potentially valuable for establishing adverse outcome pathways of chemicals in environmental risk assessment.

  17. Allelopathic effects of microcystin-LR on the germination, growth and metabolism of five charophyte species and a submerged angiosperm.

    Science.gov (United States)

    Rojo, Carmen; Segura, Matilde; Cortés, Francisco; Rodrigo, María A

    2013-11-15

    Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 μg MC-LR/L) on five charophyte species (Chara aspera, C. baltica, C. hispida, C. vulgaris and Nitella hyalina) and the angiosperm Myriophyllum spicatum. Macrophyte specimens were obtained from a restored area located in Albufera de València Natural Park, a protected coastal Mediterranean wetland. Two different experiments were conducted involving (i) the addition of MC-LR to natural sediment to evaluate its effects on seed germination and (ii) the addition of MC-LR to water cultures of macrophytes to evaluate its effects on growth and metabolic functions. In water, the MC-LR concentration decreased by 84% in two weeks; the loss was not significant in sediment. The first seedlings (all C. hispida) emerged from the wetland sediment following a delay of a few days in the presence of MC-LR. The germination rates in 8 and 16 μg MC-LR/L treatments were 44% and 11% of that occurring in the absence of MC, but these differences disappeared over time. The final density was 6-7 germlings/dm(3). Final germling length was unaffected by MC-LR. Rotifers (Lecane spp.) emerging from the natural sediment during the experiment were favored by MC-LR; the opposite pattern was observed in the cladoceran Daphnia magna. The growth rates of C. vulgaris, C. baltica and N. hyalina were unaffected by MC exposure, whereas those of C. hispida and C. aspera were reduced in the MC treatments relative to the control treatment. The concentration of chlorophyll-a and the in vivo net photosynthetic rate were lower in the presence of MC-LR, even at the lowest concentration, for all of the characeans tested. M. spicatum was sensitive to the

  18. 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

  19. Incentivizing the public to support invasive species management: eurasian milfoil reduces lakefront property values.

    Science.gov (United States)

    Olden, Julian D; Tamayo, Mariana

    2014-01-01

    Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum) invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing) and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995-2006) in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA). After accounting for structural (e.g., house size), locational (e.g., boat launch), and environmental characteristics (e.g., water clarity) of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price), corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue), justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.

  20. Total Mercury in Lake Neusiedl, Austria

    Directory of Open Access Journals (Sweden)

    Jirsa F.

    2013-04-01

    Full Text Available Between May and September 2011 a total of 361 samples from water, sediment, macrophytes and fish tissues from the shallow, slightly alkaline Lake Neusiedl were measured for their total mercury content with cold vapour atomic absorption spectroscopy (CV-AAS. Hg content of surface water was below the LOD of 0.1 μg/L and the sediments displayed contents between 0.025 and 0.113 μg/g dw, significantly correlated with the proportion of organic components (fig 1. Although these results do not point to an anthropogenic pollution of the lake, considerable amounts of mercury could be measured in fish samples and macrophytes. Both investigated submerged plant species, namely Potamogeton pectinatus and Myriophyllum spicatum show a high potential for bioaccumulation of Hg, presenting mean values of 0.245 ± 0.152 and 0.298 ± 0.115 μg/g dw respectively. Compared to freshwater fish from other unpolluted sites high amounts of Hg could be measured (fig. 2. Biomagnification and significant differences could be observed when comparing muscle samples of the planctivorous fish species rudd Scardinus erythrophthalmus (n = 10, mean = 0.084 μg/g ww with the piscivorous perch Perca fluviatilis (n = 21, mean = 0.184 μg/g ww or pike-perch Sander lucioperca (n=9, mean = 0.205 μg/g ww respectively. Significantly lower values were measured in the muscle of the piscivorous pike Esox lucius (n = 25, mean = 0.135 μg/g ww in which a strong correlation between fish age and Hg content did not occur. In addition the muscle/liver ratio of Hg in pike was significantly lower compared to the other fish species, which points to a different Hg metabolism in pike, maybe under the specific saline alkaline conditions of this lake.

  1. Incentivizing the public to support invasive species management: eurasian milfoil reduces lakefront property values.

    Directory of Open Access Journals (Sweden)

    Julian D Olden

    Full Text Available Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995-2006 in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA. After accounting for structural (e.g., house size, locational (e.g., boat launch, and environmental characteristics (e.g., water clarity of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price, corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue, justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.

  2. 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

  3. Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

    Science.gov (United States)

    Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

    2016-11-01

    The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

  4. Cs-137 in aquatic organisms in the southern Lake Keurusselkae (Finland)[Radioecology

    Energy Technology Data Exchange (ETDEWEB)

    Ilus, E.; Klemola, S.; Vartti, V.P.; Mattila, J.; Ikaeheimonen, T.K. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-04-15

    The results of a study carried out in Lake Keurusselkae, in the Finnish Lake District, are reported. The aim of the study was to collect biota samples for the INDOFERN Project from an area that was rather highly contaminated (70 kBq m{sup -2} of {sup 137}Cs in 1986) with the Chernobyl fallout in Finland. The samples were taken from a relatively small area surrounding the island of Iso Riihisaari in the southern part of the Keurusselkae water course. In total 15 samples of aquatic plants, 6 samples of aquatic animals, 1 water sample and 2 sediment cores were taken. In August 2003, the activity concentration of {sup 137}Cs in the surface water of the southern Lake Keurusselkae was 49 Bq m{sup -3}, whereas it was 310 Bq m{sup -3} in 1988, two year after the Chernobyl accident. In the relatively shallow area surrounding the island of Iso Riihisaari, the total amount of {sup 137}Cs in sediments was 32-37 kBq m{sup -2} in 2003, but in a deeper basin close to this area the total amount of {sup 137}Cs was 130 kBq m{sup -2} in 1990. The clearly highest activity concentration and concentration factor of {sup 137}Cs was found in one sample of Water horsetail (Equisetum fluviatile), 1 430 Bq kg{sup -1} dry wt; CF 29 200, whereas in another sample of the same species the concentration was only 174 Bq kg{sup -1} dry wt. In addition, the Water lily (Nymphaea candida), Spiked water millfoil (Myriophyllum spicatum), Broad-leaved pondweed (Potamogeton natans) and Yellow water lily (Nuphar lutea) seemed to be good indicators for {sup 137}Cs. The tall freshwater clam (Anodonta sp.) seemed to be a modest accumulator of {sup 137}Cs. Contrary to our results from the coastal areas of the Baltic Sea, many aquatic plants demonstrated in fresh water similar accumulation capacity of {sup 137}Cs as fish (perch and roach), while in the sea the uptake of {sup 137}Cs in fish seemed to be more efficient than in aquatic plants. (LN)

  5. Competitive ability is linked to rates of water extraction : A field study of two aridland tussock grasses.

    Science.gov (United States)

    Eissenstat, D M; Caldwell, M M

    1988-02-01

    The relative competitive abilities of Agropyron desertorum and Agropyron spicatum under rangeland conditions were compared using Artemisia tridentata ssp. wyomingensis transplants as indicator plants. We found A. desertorum to have substantially greater competitive ability than A. spicatum as manifested by the responses of Artemisia shrubs that were transplanted into nearly monospecific stands of these grass species. The Artemisia indicator plants had lower survival, growth, reproduction, and late-season water potential in the neighborhoods dominated by A. desertorum than in those dominated by A. spicatum. In similar, essentially monospecific grass stands, neutron probe soil moisture measurements showed that stands of A. desertorum extracted water more rapidly from the soil profile than did those of A. spicatum. These differences in extraction rates correlate clearly with the differences in indicator plant success in the respective grass stands. Nitrogen and phosphorus concentrations in Artemisia tissues suggested these nutrients were not limiting indicator plant growth and survival in the A. desertorum plots.

  6. Comparative analysis of the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, Alexander; Medvedeva, Marina [Institute of Biophysics SB Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    The Yenisei River is one of the largest rivers in the world, which had been subjected to radioactive contamination for over 50 years, due to operation of the Mining-and-Chemical Combine (MCC) of Rosatom at Zheleznogorsk, which had been producing weapons-grade plutonium. Bottom sediments and flood plain of the Yenisei River are contaminated by artificial radionuclides, including transuranium ones, both close to the MCC and at a considerable distance downstream. The MCC is also a source of uranium isotopes in the Yenisei. Thus, the Yenisei River basin is a unique environment for studying the mobility of both uranium isotopes and artificial radionuclides in all components of the aquatic ecosystem. The purpose of this study was to compare the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River. Samples of water, sediments, and aquatic organisms were used as study material. Aquatic organisms were represented by submerged plants, benthic-feeding fish, and zoo-benthos. The submerged plants (macrophytes) analyzed were of five species: Fontinalis antipyretica, Potamogeton lucens, Ceratophyllum demersum, Myriophyllum spicatum, and Elodea canadensis. Grayling (Timalus arcticus) represented benthic-feeding fish, and zoo-benthos species were represented by Philolimnogammarus viridis, which forms the major part of the grayling's diet. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 110 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2008-2012. Radionuclide measurements were performed using a wide range of instrumental methods: gamma-spectrometry with a 'Canberra' spectrometer (U.S.), mass spectrometry with an 'Agilent' spectrometer (U.S.), neutron activation analysis, and beta-alpha radiometry. The results obtained in this study suggest that the part of the Yenisei River ecosystem contaminated due to MCC radioactive discharges contains

  7. 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

  8. Effect of paclobutrazol on three different aquatic macrophytes under ...

    African Journals Online (AJOL)

    admin

    2013-09-25

    Sep 25, 2013 ... var. tuberosus (Orchidaceae) seedlings from distant populations: implications for assessing ecotopic differentiation. J. Torrey Bot. Soc. 136: 433-444. Lembi CA, Chand T (1992). Response of hydrilla and Eurasian watermilfoil to flurprimidol concentrations and exposure time. J. Aquat. Plant Manage. 30: 6-9.

  9. 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...

  10. Phosphate uptake kinetics for four species of submerged freshwater macrophytes measured by a 33P phosphate radioisotope technique

    DEFF Research Database (Denmark)

    Christiansen, Nina Høj; Andersen, Frede Østergaard; Jensen, Henning S.

    2016-01-01

    Phosphate (Pi) uptake kinetics were determined in shoot and root tissues for four freshwater macrophyte species, Littorella uniflora, Potamogeton perfoliatus, Myriophyllum alterniflorum and Elodea canadensis, using a radioactive 33P phosphate technique. Collection of plant material...

  11. Nieuwe vondsten van zeldzame planten in 1995 en 1996

    NARCIS (Netherlands)

    Meijden, van der Ruud; Holverda, Wout J.; Duistermaat, Leni (H.)

    1997-01-01

    As a result of nature management measures a number of rare and endangered species reappeared, often after many decades of absence on the site: Apium inundatum, Anagallis tenella, Cicendia filiformis, Echinodorus repens, Eleocharis quinqueflora, Juncus tenageia, Ludwigia palustris, Myriophyllum

  12. Las Haloragaceae de Cuba

    Directory of Open Access Journals (Sweden)

    Betancourt Gandul, Martha

    1999-12-01

    Full Text Available A study of the Haloragaceae in Cuba is presented. The presence of Proserpinaca palustris, P. pectinata. Myriophyllum laxum and M. pinnatum is confirmed, and the possible extinction of M. sparsiflorum is suggestedEstudio de la familia Haloragaceae en Cuba. Se confirma la existencia de Proserpinaca palustris, P. pectinata. Myriophyllum laxum y M, pinnatum, y se plantea la posible extinción de M. sparsiflorum.

  13. Livestock forage conditioning: bluebunch wheatgrass, Idaho fescue, and bottlebrush squirreltail.

    Science.gov (United States)

    Dave Ganskopp; Tony Svejcar; Marty. Vavra

    2004-01-01

    Research on Anderson and Scherzinger's hypothesis that spring cattle grazing can positively affect subsequent nutritional characteristics of grasses have generated mixed results. Our objectives were: 1) to evaluate fall/winter nutritional indices of bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. & Smith), Idaho fescue (...

  14. Proceedings 16th Annual Meeting, Aquatic Plant Control Research Planning and Operations Review Held at St. Paul, Minnesota on 17-19 November 1981.

    Science.gov (United States)

    1982-06-01

    every phase and every element, be it political , social, fiscal, * U.S. Army Engineer Waterways Experiment Station, CE, Vicksburg, Mississippi. 2...Potamogeton illinoensis Myaca fluvialis Ruppia maritima Myiophyllum spicatum Vallisneria americana 118 Adults were not obtained on Utricularia, but pupae

  15. Trinidad Reservoir Salvage Archaeology, 1972.

    Science.gov (United States)

    1974-09-30

    Symphori- carpos vaccinoides 140 Occurrence: Southern Rocky Mountains and Arizona ALPINE MEADOWS AND BARREN (AGROSTIS, CAREX , FESTUCA, POA Physiognomy...Usually short grasses and sedgesa, dense to very open with extensive barren areas; many forbs Dominants: Bentgrass (Argrostis spp.) Sedges ( Carex app...Spike trisetine (Trisetwn spicatum) Other Components: Achilica app., Antennaria app., Aquilegia app., Arenaria app., Castilleja app., Draba spp., Erigeron

  16. A Literature Survey on the Wetland Vegetation of Alaska.

    Science.gov (United States)

    1982-08-01

    occasionally Ranunculus hyperboreus, R. gmelinii, R. aquatilis, Sparganium hyperboreum, and, rarely, Potamogeton pectinatus and P. filiformis grow...spicatum, Potamogeton spp., and occasionally Lemna trisulca are found. In shallower water Potamogeton -, filiformis, P. pectinatus , Zannichellia palustris...Infrequently, the submerged species Potamogeton alpinus, P. filiformis, and P. pectinatus * are found. The most consistent species in lakes around Umiat

  17. Effect of plant growth regulators (PGRs) on micropropagation of a ...

    African Journals Online (AJOL)

    A complete micropropagation protocol was developed by applying different plant growth regulators (PGRs) of a vulnerable and high value aromatic medicinal plant, Hedychium spicatum. Three cytokinins, 6-benzyladenine (BA), kinetin (KN) and thidiazuron (TDZ) were used and among these, the lower concentration of TDZ ...

  18. An Ecological Land Survey for Fort Greely, Alaska

    Science.gov (United States)

    2001-02-01

    signifies >60% frequency within ecotype.) a. Alpine. Diapensia lapponica 0 1 Trisetum spicatum 0 0 0 Artemisia arctica 0 1 1 Saxifraga tricuspidata 1 0 0...Racomitrium lanuginosum 3 1 1 Rhytidium rugosum 1 1 1 Calamagrostis purpurascens 3 1 Stereocaulon spp. 1 4 2 Saxifraga punctata 0 0 Oxytropis nigrescens

  19. A Survey of the Invasive Aquatic and Riparian Plants of the Lower Rio Grande

    Science.gov (United States)

    2005-04-01

    Steud Polygonum spp. smartweed N Emergent Pontederia cordata L. pickerelweed N Emergent Potamogeton illinoensis Illinois pondweed N Submersed Morong...H. verticillata Ludwigia spp. M. spicatum P. cordata Tamarisk spp. Polygonum spp. P. illinoensis Scirpus spp. Above Eagle Pass, boat launch 8/19/03

  20. USING ROTIFER POPULATION DEMOGRAPHIC PARAMETERS TO ASSESS IMPACTS OF THE DEGRADATION PRODUCTS FROM TRINITROTOLUENE PHYTOREMEDIATION

    Science.gov (United States)

    The objective of this study was to evaluate the aquatic chronic lethal and sublethal toxicity effects from the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (2,4,6-TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus...

  1. 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...

  2. 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

  3. 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.

  4. EUPHRESCO – DeCLAIM: a decision support system, for control of alien invasive macrophytes

    OpenAIRE

    van Valkenburg, J.L.C.H.; Lotz, L.A.P.; Roijackers, R.M.M.; Newman, J.R.

    2011-01-01

    This report contains the result of a research programme on four invasive aquatic macrophytes, Cabomba caroliniana (Fanwort), Hydrocotyle ranunculoides (Floating pennywort) , Myriophyllum aquaticum (Parrott’s feather) and Ludwigia grandiflora (Water primrose). The collaborative project was intended to generate a prototype decision support system for optimising control measures for these species, considered to be the four most troublesome invasive alien aquatic weeds at present i...

  5. Leachates and elemental ratios of macrophytes and benthic algae of an Andean high altitude wetland

    OpenAIRE

    Beatriz MODENUTTI; Esteban BALSEIRO; Marcela BASTIDAS NAVARRO; Florencia CUASSOLO

    2011-01-01

    In wetlands, macrophytes and filamentous algae constitute an important carbon source for the total content of Dissolved Organic Matter (DOM) of the environment. Mallín wetland meadows are highly diverse and rare habitats in Patagonia, that can be characterized as wet meadows with a dense cover mainly dominated by herbaceous plants. We carried out a field study comparing elemental composition (C:N:P) of benthic algae (Spirogyra sp. and Zygnema sp.) and the submerged macrophyte (Myriophyllum qu...

  6. Comprehensive Monitoring Program: Final Biota Annual Report for 1989. Volume 3

    Science.gov (United States)

    1990-06-01

    appears that P. pectinatus , sego pondweed, was the species collected in both years; it was mistakenly called leafy pondweed in 1988. The species...acronym of POFO has been reassigned to P. pectinatus , and for future collections, the POPE acronym will be used for P. pectinatus . Voucher specimens of P... pectinatus , C. demersum and Myriophyllum have been collected from the RMA to document the current status of aquatic * plant species. * Black Bullhead

  7. Nieuwe vondsten van zeldzame planten in 1995 en 1996

    OpenAIRE

    Meijden, van der, R.; Holverda, Wout J.; Duistermaat, Leni

    1997-01-01

    As a result of nature management measures a number of rare and endangered species reappeared, often after many decades of absence on the site: Apium inundatum, Anagallis tenella, Cicendia filiformis, Echinodorus repens, Eleocharis quinqueflora, Juncus tenageia, Ludwigia palustris, Myriophyllum alterniflorum, Pilularia globulifera and Viola persicifolia; the latest news (summer 1997) being the rediscovery of the presumably extinct Juncus capitatus. New are the alien species Nonea lutea, Salix ...

  8. Maçonneries murales de brique dans l’Espagne médiévale

    Directory of Open Access Journals (Sweden)

    Araguas, Philippe

    2005-12-01

    Full Text Available Few are the different bonds of brickwork in medievel Spain. Walls entirely built with bricks are scarce. Brick is used combining header bond and sideways bond, opus spicatum or vertical bond. Among mixed bonds, the «toledan bond» is very characteristic. A diachronic cartography can show the variation of these different bonds according to time and historical regionsLes modalités d’appareillage des murs de brique dans l’Espagne médiévale sont peu variées. Rares sont les murs construits entièrement en brique ; celle-ci est utilisée en appareil de revêtement en combinant disposition «en carreau» et « en boutisse, en opus spicatum ou «ce chant». Parmi les appareils mixtes, l’ «appareil tolédan» est aisément identifiable. Une cartographie diachronique permet de rendre compte de la variation de ces modes d’utilisation de la brique.

  9. Tratamiento de aguas eutrofizadas de la bahía interior de Puno, Perú, con el uso de dos Macrófitas

    OpenAIRE

    Jimenez Monroy, Luis Llberto; Universidad Nacional del Altiplano – Puno Perú; Jahuira Huarcaya, Faustino Adolfo; Universidad Nacional del Altiplano – Puno Perú; Ibañez Quispe, Vladimiro; Universidad Nacional del Altiplano – Puno Perú

    2016-01-01

    La investigación tuvo como propósito determinar los niveles de Nitrógeno Total (NT) y Fósforo Total (PT) de las aguas contaminadas de la bahía interior de la ciudad de Puno, del sector denominado Isla Espinar, de la boca toma de muelle, sector Huaje, y evaluar la eficiencia de dos macrófitas, como el Elodea Canadensis Michax (llacho) y Myriophyllum Quitensis Kunth (hinojo) para la remoción del Nitrógeno y Fósforo. Para valorar las muestras, procedentes del sector Parinas de la Península de Ch...

  10. Anatomical structure and chloroplasts ultrastructural peculiarity of some hydrophytes leaves

    Directory of Open Access Journals (Sweden)

    Olena M. Nedukha

    2015-05-01

    Full Text Available The comparative analysis of the anatomical study, chloroplast ultrastructure and pigments content of submerged leaves of Potamogeton perfoliatus, P. pectinatus and Myriophyllum spіcatum at budding-flowering stage with light microscopy, transmission electron microscopic and biochemical methods were realized. The absent of stomata, the presence of undifferentiated mesophyll was shown with anatomical study of hydrophytes leaves. The common and distinctions signs of chloroplast ultrastructure in leaf photosynthesizing parenchyma were revealed in dependent from species. The structural changes of leaf phonotypical plasticity are examined as adaptative device of submerged leaves under influence of altered environment.

  11. Spatial and molecular aspects of hemiparasites parasitising Acacia spp

    DEFF Research Database (Denmark)

    Dueholm, Bjørn

    shrubs neighbouring the root hemiparasites. The hemiparasites may further impair reproduction of the host and impact other trophic levels associated with the host. Traits of Acacia ligulata were therefore investigated further in terms of seeds per seedpods, seed mass and phyllode C/N ratios. Indications...... not result in differences of larval mass. Finally, to further investigate the belowground-aboveground link, phyllodes from A. acuminata were used for an RNA-sequencing (RNA-Seq) experiment to investigate gene expression in individuals, non-parasitised or parasitised by Santalum spicatum. Two transcriptomes....... The annotated transcriptomes together with identified markers enable further relational and gene expression studies with either shoot or root hemiparasites in either natural communities or plantations....

  12. Sandalwood Research: A Global Perspective

    Directory of Open Access Journals (Sweden)

    S.M.C.U.P. Subasinghe

    2013-04-01

    Full Text Available Sandalwood is a commercially and culturally important plant species belonging to the familySantalaceae and the genus Santalum. Sandalwood oil extracted from the heartwood has been used forperfumery, medicinal, religious and cultural purposes over centuries of years. In addition to oil, the woodand its powder are used for religious, cultural and medicinal purposes especially in the Asian and Arabregions. There are around 18 sandalwood species belonging to the genus Santalum which are; S.freycinetianum, S. haleakalae, S. ellipticum, S. peniculatum, S. pyrularium, S. involutum, S. boninese, S.insulare, S. austrocaledonicum, S. yasi, S. macgregorii, S. accuminatum, S. murrayanum, S. obtusifolium,S. lanceolatum, S. fernandezianum, S. salicifolium and S. spicatum. All the sandalwood species areidentified as obligate wood hemi-parasites which means they absorb certain nutrients such as phosphatesand nitrates from the host trees via root connections called haustoria.

  13. Effect of Lake Trophic Status and Rooted Macrophytes on Community Composition and Abundance of Ammonia-oxidizing Prokaryotes in Freshwater Sediments

    DEFF Research Database (Denmark)

    Herrmann, Martina; Saunders, Aaron Marc; Schramm, Andreas

    2009-01-01

    Communities of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in freshwater sediments and those in association with the root system of the macrophyte species Littorella uniflora, Juncus bulbosus, and Myriophyllum alterniflorum were compared for seven oligotrophic to mesotrophic softwater lakes....../N ratios. AOA communities could be grouped according to lake trophic status and pH; plant species-specific communities were not detected, and no grouping was apparent for AOB communities. Relative abundance, determined by quantitative PCR targeting amoA, was always low for AOB (...) and slightly higher for AOA in unvegetated sediment and AOA in association with M. alterniflorum (0.01 to 2%), while AOA accounted for up to 5% in the rhizospheres of L. uniflora and J. bulbosus. These results indicate that (i) AOA are at least as numerous as AOB in freshwater sediments, (ii) aquatic...

  14. Primary productivity of submerged macrophytes in West Blue Lake, Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Love, R.J.R.; Robinson, G.G.C.

    1977-01-15

    The productivity of Potamogeton Richardsonii, P. pectinatus, Myriophyllum alterniflorum, Megalodonta Beckii, and Chara vulgaris in West Blue Lake, Manitoba, is reported. Measurements of changes in biomass and assimilation of /sup 14/CO/sub 2/ in random and non-random samples throughout the growing season of 1973 were used. Changes in biomass of P. Richardsonii, M. alterniflorum, M. Beckii, and C. vulgaris determined from random samples compared favorably with those determined from non-random samples. This was not the case for P. pectinatus because of its restricted occurrence. Similarly, measurements of /sup 14/CO/sub 2/ assimilation in random samples of P. Richardsonii, M. alterniflorum, and M. Beckii compared well with non-random samples. Productivity values derived from /sup 14/CO/sub 2/ uptake were far in excess of those attained from biomass changes. Seasonal trends of production and the depth distribution of production are discussed, and macrophyte production is compared with phytoplankton production.

  15. Elemental composition of native wetland plants in constructed mesocosm treatment wetlands.

    Science.gov (United States)

    Collins, Beverly S; Sharitz, Rebecca R; Coughlin, Daniel P

    2005-05-01

    Plants that accumulate a small percentage of metals in constructed treatment wetlands can contribute to remediation of acidic, metal contaminated runoff waters from coal mines or processing areas. We examined root and shoot concentrations of elements in four perennial wetland species over two seasons in mesocosm wetland systems designed to remediate water from a coal pile runoff basin. Deep wetlands in each system contained Myriophyllum aquaticum and Nymphaea odorata; shallow wetlands contained Juncus effusus and Pontederia cordata. Shoot elemental concentrations differed between plants of deep and shallow wetlands, with higher Zn, Al, and Fe concentrations in plants in shallow wetlands and higher Na, Mn, and P concentrations in plants in deep wetlands. Root and shoot concentrations of most elements differed between species in each wetland type. Over two seasons, these four common wetland plants did help remediate acidic, metal-contaminated runoff from a coal storage pile.

  16. The biological control of aquatic weeds in South Africa: Current status and future challenges

    Directory of Open Access Journals (Sweden)

    Martin P. Hill

    2017-03-01

    Full Text Available Background: Aquatic ecosystems in South Africa are prone to invasion by several invasive alien aquatic weeds, most notably, Eichhornia crassipes (Mart. Solms-Laub. (Pontederiaceae (water hyacinth; Pistia stratiotes L. (Araceae (water lettuce; Salvinia molesta D.S. Mitch. (Salviniaceae (salvinia; Myriophyllum aquaticum (Vell. Conc. Verd. (parrot’s feather; and Azolla filiculoides Lam. (Azollaceae (red water fern. Objective: We review the biological control programme on waterweeds in South Africa. Results: Our review shows significant reductions in the extent of invasions, and a return on biodiversity and socio-economic benefits through the use of this method. These studies provide justification for the control of widespread and emerging freshwater invasive alien aquatic weeds in South Africa. Conclusions: The long-term management of alien aquatic vegetation relies on the correct implementation of biological control for those species already in the country and the prevention of other species entering South Africa.

  17. [Macrophytes from some high Andean lakes of Ecuador and their low potential as bioindicators of eutrophication].

    Science.gov (United States)

    Kiersch, Benjamin; Mühleck, Ralf; Gunkel, Günter

    2004-12-01

    The occurrence of macrophyte in three high Andean lakes of Ecuador, Lago San Pablo, Laguna La Mica and Lago Cuicocha was recorded in 5-9 transects per lake. The first two lakes are eutrophic, the third is an extremely oligotrophic caldera lake. The dominant species in eutrophic lakes are Ceratophyllum demersum, Myriophyllum quitense, Polamogeton illinoensis, P. striatus and Elodea matthewsii. In the oligotrophic lake P. pectinatus, P. illinoensis, and the Characeae Chara rusbyana, Ch. globularis and Nitella acuminata occur. The maximum depth of the macrophyte's presence can be used as an indicator of the trophic state, ranging from about 5 m in Mica to 35 m in Cuicocha. The bioindication value of the macrophyte species in these high Andean lakes is low, because few species occur and because some of them are not specific to environmental conditions.

  18. Induction of Reduced Photorespiratory Activity in Submersed and Amphibious Aquatic Macrophytes 1

    Science.gov (United States)

    Salvucci, Michael E.; Bowes, George

    1981-01-01

    Incubation under water in a 30 C/14-hour or 12 C/10-hour photoperiod caused the CO2 compensation points of 10 aquatic macrophytes to decrease below 25 or increase above 50 microliters CO2 per liter, respectively. Submerged and aerial leaves of two amphibious angiosperms (Myriophyllum brasiliense and Proserpinaca palustris) maintained high compensation points when incubated in air but, when the submerged or aerial leaves of Proserpinaca were incubated under water, the compensation points dropped as low as 10. This suggests that, in addition to temperature and photoperiod, some factor associated with submergence regulates the compensation point of aquatic plants. In the high-compensation point plants, photorespiration, as a percentage of net photosynthesis, was equivalent to that in terrestrial C3 plants. For Hydrilla verticillata, the decreasing CO2 compensation points (110, 40, and 10) were associated with reduced photorespiration, as indicated by decreased O2 inhibition, decreased rates of CO2 evolution into CO2-free air, and increased net photosynthetic rates. The decrease in the CO2 compensation points of Hydrilla, Egeria densa, and Cabomba caroliniana was accompanied by an increase in the activity of phosphoenolpyruvate, but not of ribulose bisphosphate, carboxylase. In Hydrilla, several C4 enzymes also increased in activity to the following levels (micromoles per gram fresh weight per hour): pyruvate Pi dikinase (35), pyrophosphatase (716), adenylate kinase (525), NAD and NADP malate dehydrogenase (6565 and 30), NAD and NADP malic enzymes (239 and 44), and aspartate and alanine aminotransferases (357 and 85), whereas glycolate oxidase (6) and phosphoglycolate and phosphoglycerate phosphatases (76 and 32) showed no change. Glycolate dehydrogenase and phosphoenolpyruvate carboxykinase were undetectable. The reduced photorespiration in these plants may be due to increased CO2 fixation via a C4 acid pathway. However, for three Myriophyllum species, some other

  19. Induction of reduced photorespiratory activity in submersed and amphibious aquatic macrophytes.

    Science.gov (United States)

    Salvucci, M E; Bowes, G

    1981-02-01

    Incubation under water in a 30 C/14-hour or 12 C/10-hour photoperiod caused the CO(2) compensation points of 10 aquatic macrophytes to decrease below 25 or increase above 50 microliters CO(2) per liter, respectively. Submerged and aerial leaves of two amphibious angiosperms (Myriophyllum brasiliense and Proserpinaca palustris) maintained high compensation points when incubated in air but, when the submerged or aerial leaves of Proserpinaca were incubated under water, the compensation points dropped as low as 10. This suggests that, in addition to temperature and photoperiod, some factor associated with submergence regulates the compensation point of aquatic plants. In the high-compensation point plants, photorespiration, as a percentage of net photosynthesis, was equivalent to that in terrestrial C(3) plants. For Hydrilla verticillata, the decreasing CO(2) compensation points (110, 40, and 10) were associated with reduced photorespiration, as indicated by decreased O(2) inhibition, decreased rates of CO(2) evolution into CO(2)-free air, and increased net photosynthetic rates.The decrease in the CO(2) compensation points of Hydrilla, Egeria densa, and Cabomba caroliniana was accompanied by an increase in the activity of phosphoenolpyruvate, but not of ribulose bisphosphate, carboxylase. In Hydrilla, several C(4) enzymes also increased in activity to the following levels (micromoles per gram fresh weight per hour): pyruvate Pi dikinase (35), pyrophosphatase (716), adenylate kinase (525), NAD and NADP malate dehydrogenase (6565 and 30), NAD and NADP malic enzymes (239 and 44), and aspartate and alanine aminotransferases (357 and 85), whereas glycolate oxidase (6) and phosphoglycolate and phosphoglycerate phosphatases (76 and 32) showed no change. Glycolate dehydrogenase and phosphoenolpyruvate carboxykinase were undetectable. The reduced photorespiration in these plants may be due to increased CO(2) fixation via a C(4) acid pathway. However, for three Myriophyllum

  20. Screening of Asteraceae (Compositae Plant Extracts for Larvicidal Activity against Aedes fluviatilis (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Maria E Macêdo

    1997-07-01

    Full Text Available Ethanol extracts of 83 plants species belonging to the Asteraceae (Compositae family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis - Diptera: Culicidae. The extract from Tagetes minuta was the most active with a LC90 of 1.5 mg/l and LC50 of 1.0 mg/l. This plant has been the object of several studies by other groups and its active components have already been identified as thiophene derivatives, a class of compounds present in many Asteraceae species. The extract of Eclipta paniculata was also significantly active, with a LC90 of 17.2 mg/l and LC50 of 3.3 mg/l and no previous studies on its larvicidal activity or chemical composition could be found in the literature. Extracts of Achryrocline satureoides, Gnaphalium spicatum, Senecio brasiliensis, Trixis vauthieri, Tagetes patula and Vernonia ammophila were less active, killing more than 50% of the larvae only at the higher dose tested (100 mg/l.

  1. A synopsis of the South American Lepidium (Brassicaceae

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    Ihsan A. Al-Shehbaz

    2010-01-01

    Full Text Available Cincuenta especies nativas y 12 naturalizadas de Lepidium crecen en América del Sur, se presenta una clave para las 62 especies. Se describen e ilustran tres nuevas especies de Argentina (L. hickenii, L. pedersenii y L. santacruzensis y dos para Perú (L. cuzcoensis y L. werffii, y se discuten sus relaciones con sus especies más afines. Se propone Lepidium crassius comb. nov., se designa lectotipo para 19 binomios (Coronopus didymus var. macrocarpus, C. didymus var. procumbens, L. abrotanifolium var. steinmannii, L. affine, L. argentinum, L. auriculatum, L. bonariense var. pseudovirginicum, L. calycinum var. integrifolium, L. costaricense, L. cumingianum var. orbiculatum, L. cumingianum subsp. berteroanum, L. depressum, L. myrianthum, L. neglectum, L. parodii, L. pubescens var. fallax, L. subvaginatum, L. virginicum subsp. centrali-americanum, Thlaspi campestre, y se reducen a sinónimos otros 17 nombres (Coronopus leptocarpus, C. leptocarpus var. microcarpus, L. boelckii, L. bonariense var. gayi, L. bonariense var. pseudovirginicum, L. brevicaule, L. calycinum, L. danielsii, L. demissum, L. kalenbornii, L. morrisonii, L. peruvianum, L. philippianum var. boliviense, L. raimondii, L. scabrifructum, L. spicatum var. caylx-persistente, L. subvaginatum. L. depressum y L. rahmeri son nuevos registros para la Argentina.

  2. Las macrófitas de algunos lagos alto-andinos del Ecuador y su bajo potencial como bioindicadores de eutrofización

    Directory of Open Access Journals (Sweden)

    Benjamin Kiersch

    2004-12-01

    Full Text Available Se estudió la presencia de macrófitas en tres lagos de altoandinos en Ecuador,Lago San Pablo,Laguna La Mica y Lago Cuicocha.Los primeros dos son eutróficos, mientras que el último es un lago de caldera extremadamente oligotrófico.Las especies dominantes en los lagos eutróficos son:Ceratophyllum demersum , Myriophyllum quitense ,Potamogeton illinoensis ,P. striatus y Elodea matthewsii .En el lago oligotrófico están presentes P.pectinatus,P.illinoensi s,y las Characeae Chara rusbyabana ,Ch.globularis y Nitella acuminata .La máxima profundidad para la presencia de macrófitas puede ser usada como un indicador del estado de eutroficación,la cual va desde 5 m en la Laguna Mica a 35 m en el Lago Cuicocha.El valor de la bioindicación de las especies de macrófitas en estos lagos altoandinos es bajo,debido a que solo unas pocas especies están presentes,y algunas de ellas no son específicas para las condiciones ambientales.Macrophytes from some high Andean lakes of Ecuador and their low potential as bioindicators of eutrophication .The occurrence of macrophyte in three high Andean lakes of Ecuador,Lago San Pablo, Laguna La Mica and Lago Cuicocha was recorded in 5-9 transects per lake.The first two lakes are eutrophic, the third is an extremely oligotrophic caldera lake.The dominant species in eutrophic lakes are Ceratophyllum demersum ,Myriophyllum quitense ,Potamogeton illinoensis ,P.striatus and Elodea matthewsii .In the oligotrophic lake P.pectinatus,P.illinoensi s,and the Characeae Chara rusbyana ,Ch.globularis and Nitella acuminata occur.The maximum depth of the macrophyte ’s presence can be used as an indicator of the trophic state,ranging from about 5 m in Mica to 35 m in Cuicocha.The bioindication value of the macrophyte species in these high Andean lakes is low,because few species occur and because some of them are not specific to environmental conditions.Rev.Biol.Trop.52(4:829-837.Epub 2005 Jun 24.

  3. Avaliação da sensibilidade de diversas espécies de plantas daninhas aquáticas ao carfentrazone-ethyl, em ambiente controlado Assessment of sensitivity of several aquatic weeds to carfentrazone-ethyl under controlled environment

    Directory of Open Access Journals (Sweden)

    L.L. Foloni

    2005-06-01

    Full Text Available Plantas aquáticas, especialmente macrófitas, tornam-se sério problema em hidrelétricas, afetando a múltipla utilização dos corpos d'água, incluindo produção de peixes e atividades de pesca, perdas d'água por evapotranspiração, esportes aquáticos, canoagem, irrigação e produção de energia nas usinas hidrelétricas. Com o objetivo de analisar o potencial de uso do carfentrazone-ethyl no controle das principais plantas daninhas aquáticas no Brasil, foi instalado um experimento em vasos com água. Utilizaram-se os seguintes tratamentos herbicidas (g i.a. ha-1: carfentrazone-ethyl a 15, 30 e 60; glyphosate a 4.536; 2,4-D a 4.690; imazapyr a 1.250; e uma testemunha sem herbicida. Esses tratamentos foram testados nas seguintes espécies: Eichhornia crassipes, Salvinia auriculata, Pistia stratiotes, Myriophyllum aquaticum, Brachiaria arrecta, Hydrocotyle umbellata, Typha sp. e Echinochloa polystachya. As avaliações foram efetuadas aos 7, 14, 21 e 28 dias após os tratamentos. Os resultados mostraram que o carfentrazone-ethyl foi eficiente no controle de E. crassipes (maior dose e P. stratiotes (duas maiores doses, com efeito supressivo sobre S. auriculata. Foi observado que nas outras plantas daninhas estudadas não houve eficiência de controle.Aquatic weeds, especially macrophytes, are a serious problem in hydroelectric plant systems, affecting the multiple use of water, such as fish production and fishing activities, water losses by evapotranspiration, aquatic sports, boating, irrigation and hydroelectric power production. An experiment using boxes filled with water was carried out to analyze the potential use of carfentrazone-ethyl in the control of the main aquatic weeds in Brazil. The following herbicide treatments (g i.a. ha-1 were used: carfentrazone-ethyl at 15, 30 and 60; glyphosate at 4,536; 2,4D at 4,690; imazapyr at 1,250, and no herbicide. These treatments were tested on the species: Eichhornia crassipes, Salvinia

  4. LES PROLIFÉRATIONS VÉGÉTALES AQUATIQUES EN FRANCE : CARACTÈRES BIOLOGIQUES ET ÉCOLOGIQUES DES PRINCIPALES ESPÈCES ET MILIEUX PROPICES. I. BILAN D’UNE SYNTHÈSE BIBLIOGRAPHIQUE.

    Directory of Open Access Journals (Sweden)

    PELTRE M. C.

    2002-04-01

    Full Text Available La gestion des milieux aquatiques touchés par des proliférations végétales rencontre de nombreuses difficultés liées à l’appréciation des déséquilibres induits. Parmi celles-ci figure l’évaluation de l’intensité des phénomènes, tant à l’échelle spatiale que temporelle, et celle des nuisances qui réduisent la satisfaction des usages. Un inventaire des principaux groupes de végétaux concernés, considérés comme des « espèces à risque de prolifération » a été dressé après examen de divers constats recensés sur le territoire français. Ce sont notamment des macro-algues, des cyanobactéries, des phanérogames hydrophytes autochtones comme Ranunculus sp., Potamogeton sp., Myriophyllum sp., Ceratophyllum sp., Lemna sp., et des hydrophytes introduits comme Elodea sp., Lagarosiphon sp., Ludwigia sp., Myriophyllum aquaticum, certains hélophytes et deux espèces rivulaires exotiques (Fallopia japonica et Impatiens glandulifera. Leurs potentialités importantes de développement et de propagation s’expliquent par leurs stratégies biologiques, dont certaines adaptations morphologiques et physiologiques et divers moyens de multiplication végétative. Les milieux propices aux proliférations présentent des conditions environnementales particulières : fort éclairement souvent lié à une faible profondeur et à un échauffement des eaux, conditions hydrologiques stables, minéralisation moyenne à forte, niveau trophique souvent élevé. La conjonction de ces deux composantes (espèce à risque et milieu propice, crée ainsi les conditions d’une prolifération et définit des situations à risque minimal ou maximal. Ces connaissances concourent à une meilleure définition des situations de risque de prolifération et peuvent fournir des informations utiles quant aux conditions et aux limites d’application des techniques de gestion et de contrôle de ces phénomènes.

  5. Uso de “wetland” construído para tratamento de resíduos - DOI: 10.4025/actascibiolsci.v30i3.5002 Constructed wetland in wastewater treatment - DOI: 10.4025/actascibiolsci.v30i3.5002

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Sipaúba-Tavares

    2008-10-01

    Full Text Available Variáveis físico-químicas da água e do solo foram avaliadas a fim de verificar a eficiência de um “wetland” construído no tratamento de resíduos. Foram escolhidas oito espécies de macrófitas baseadas na capacidade de retenção e disponibilidade no local de estudo. Dentre elas estão: Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum e Thypha domingensis. Foram amostrados dois pontos um na entrada e outro na saída de água do “wetland”. Diferenças significativas (p -1 e de condutividade, acima de 80 µS cm-1. As concentrações de clorofila-a decresceram ao passar pelo “wetland”, sendo mais elevadas no período de chuva (período de engorda de peixe. Amônia, fósforo total, DBO5, fósforo e matéria orgânica do sedimento decresceram ao passar pelo “wetland” construído para indicar a eficiência desse sistema. Assim, essa tecnologia biológica (macrófitas aquáticas apresenta-se como uma opção adequada para melhoria de efluentes de aquicultura e de suinocultura.Physical and chemical variables of soil and water were measured to determine the effectiveness of a constructed wetland for wastewater treatment. Eight different macrophyte species, namely Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum and Thypha domingensis, were transplanted. Inlet water and outlet water were the two sampling sites evaluated. There were significant differences (p -1, and conductivity was high, above 80 µS cm-1. Chlorophyll-a levels generally tended to decrease at the wetland outlet and were higher during the rainy period (fish growth period. Results show that ammonia, total phosphorus, BOD5, phosphorus and organic matter in the sediment removals in the constructed wetland were higher, indicating that macrophytes played an

  6. Constructed wetland in wastewater treatment = Uso de “wetland” construído para tratamento de resíduos

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Sipaúba-Tavares

    2008-07-01

    Full Text Available Physical and chemical variables of soil and water were measured todetermine the effectiveness of a constructed wetland for wastewater treatment. Eight different macrophyte species, namely Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum and Thypha domingensis, were transplanted. Inlet water and outlet water were the two sampling sites evaluated. There were significant differences (p Variáveis físico-químicas da água e do solo foram avaliadas a fim de verificar a eficiência de um “wetland” construído no tratamento de resíduos. Foram escolhidas oito espécies de macrófitas baseadas na capacidade de retenção e disponibilidade no local de estudo. Dentreelas estão: Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum e Thypha domingensis.Foram amostrados dois pontos um na entrada e outro na saída de água do “wetland”. Diferenças significativas (p < 0,05 foram observadas entre a entrada e saída do “wetland” em relação às variáveis limnológicas. Em geral, foram observadas concentrações de oxigêniodissolvido acima de 4 mg L-1 e de condutividade, acima de 80 mS cm-1. As concentrações de clorofila-a decresceram ao passar pelo “wetland”, sendo mais elevadas no período de chuva (período de engorda de peixe. Amônia, fósforo total, DBO5, fósforo e matéria orgânica dosedimento decresceram ao passar pelo “wetland” construído para indicar a eficiência desse sistema. Assim, essa tecnologia biológica (macrófitas aquáticas apresenta-se como uma opção adequada para melhoria de efluentes de aquicultura e de suinocultura.

  7. ECOLOGICAL CONTROL EQUIPMENT AND TECHNOLOGY OF UNDERWATER VEGETATION DEVELOPMENT

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    V. TITINSCHNEIDER

    2008-10-01

    Full Text Available The excess of aquatic submerse vegetation development carries to the reduction of the real rearing area for the piscicultural material from the production farms and allow nestling of the ichthyophages bird species that decrease the fish production. Aquatic submerse vegetation stumble the utilization of aquatic zones for recreation and also wright function of basins utilized for the electric energy production, of micro electricity works through obstruction of the dams grid. The control of the aquatic submerse vegetation development, for Myriophyllum verticillatum, Ceratophyllum submersum, Urticularia vulgaris, Potamogeton natans, Nimphoides peltata species it is accomplish through the removing of some parts of these, preferably with all the stump system. Usually, these its accomplish with the floating equipments fit up with the thermic engines and the propulsion and governating elements who have harm over the fish and some others aquatic organisms through the noise, the displacing a large quality of water caused of propulsion systems and through the noxes elimination (flue, carburant trails, etc.. These technologies reside from the evacuation of the aquatic submerse vegetation and the stump systems of these with the help of an adjustable rake, hang up from the coast by a rope, wrapped to a drummer, who is trained by a motto-propeller group with a small installed power.

  8. Variability of sediment-contact tests in freshwater sediments with low-level anthropogenic contamination - Determination of toxicity thresholds

    Energy Technology Data Exchange (ETDEWEB)

    Hoess, S., E-mail: hoess@ecossa.d [Ecossa, Giselastr. 6, 82319 Starnberg (Germany); Institute of Biodiversity - Network (IBN), Dreikronengasse 2, 93047 Regensburg (Germany); Ahlf, W., E-mail: ahlf@tu-harburg.d [Institute of Environmental Technology and Energy Economics, Technical University Hamburg-Harburg, Eissendorfer Str. 40, 21071 Hamburg (Germany); Fahnenstich, C. [Institute of Environmental Technology and Energy Economics, Technical University Hamburg-Harburg, Eissendorfer Str. 40, 21071 Hamburg (Germany); Gilberg, D., E-mail: d-gilberg@ect.d [ECT Oekotoxikologie, Boettgerstr. 2-14, 65439 Floersheim (Germany); Hollert, H., E-mail: henner.hollert@bio5.rwth-aachen.d [Department of Ecosystem Analysis, Institute for Environmental Research (Biology 5), RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Melbye, K. [Dr. Fintelmann and Dr. Meyer, Mendelssohnstr. 15D, 22761 Hamburg (Germany); Meller, M., E-mail: m-meller@ecotox-consult.d [ECT Oekotoxikologie, Boettgerstr. 2-14, 65439 Floersheim (Germany); Hammers-Wirtz, M., E-mail: hammers-wirtz@gaiac.rwth-aachen.d [Research Institute for Ecosystem Analysis and Assessment (gaiac), RWTH Aachen University, Worringerweg 1, 52056 Aachen (Germany); Heininger, P., E-mail: heininger@bafg.d [Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56070 Koblenz (Germany); Neumann-Hensel, H., E-mail: hensel@fintelmann-meyer.d [Dr. Fintelmann and Dr. Meyer, Mendelssohnstr. 15D, 22761 Hamburg (Germany); Ottermanns, R., E-mail: ottermanns@bio5.rwth-aachen.d [Chair for Environmental Biology and Chemodynamics, Institute for Environmental Research (Biology 5), RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Ratte, H.-T., E-mail: toni.ratte@bio5.rwth-aachen.d [Chair for Environmental Biology and Chemodynamics, Institute for Environmental Research (Biology 5), RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany)

    2010-09-15

    Freshwater sediments with low levels of anthropogenic contamination and a broad range of geochemical properties were investigated using various sediment-contact tests in order to study the natural variability and to define toxicity thresholds for the various toxicity endpoints. Tests were performed with bacteria (Arthrobacter globiformis), yeast (Saccharomyces cerevisiae), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), higher plants (Myriophyllum aquaticum), and the eggs of zebrafish (Danio rerio). The variability in the response of some of the contact tests could be explained by particle size distribution and organic content. Only for two native sediments could a pollution effect not be excluded. Based on the minimal detectable difference (MDD) and the maximal tolerable inhibition (MTI), toxicity thresholds (% inhibition compared to the control) were derived for each toxicity parameter: >20% for plant growth and fish-egg survival, >25% for nematode growth and oligochaete reproduction, >50% for nematode reproduction and >60% for bacterial enzyme activity. - Sediment-contact tests require toxicity thresholds based on their variability in native sediments with low-level contamination.

  9. Classification of explosives transformation products in plant tissue

    Energy Technology Data Exchange (ETDEWEB)

    Larson, S.L.; Jones, R.P. (Army Corps of Engineers, Vicksburg, MI (United States). Waterways Experiment Station); Escalon, L.; Parker, D. (AScI Corp., McLean, VA (United States))

    1999-06-01

    Explosives contamination in surface or groundwater used for the irrigation of food crops and phytoremediation of explosives-contaminated soil or water using plant-assisted biodegradation have brought about concerns as to the fate of explosives in plants. Liquid scintillation counting, high-performance liquid chromatography, and gel permeation chromatography were utilized to characterize explosives (hexahydro-1,3,5-trinitro-1,3,5-triazine and trinitrotoluene) and their metabolites in plant tissues obtained from three separate studies. Analyzing tissues of yellow nutsedge (Cyperus esculentus), corn (Zea mays), lettuce (Lacuta sativa), tomato (Lyopersicum esculentum), radish (Raphanus sativus), and parrot feather (Myriophyllum aquaticum) from three studies where exposure to explosives at nontoxic levels occurred showed that extensive transformation of the explosive contaminant occurred, variations were noted in uptake and transformation between terrestrial and aquatic plants, the products had significantly higher polarity and water solubility than the parent compounds, and the molecular sizes of the transformation products were significantly greater than those of the parent compounds.

  10. 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.

  11. [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.

  12. A model for the effect of submerged aquatic vegetation on turbulence induced by an oscillating grid

    Science.gov (United States)

    Pujol, Dolors; Colomer, Jordi; Serra, Teresa; Casamitjana, Xavier

    2012-12-01

    The aim of this study is to model, under controlled laboratory conditions, the effect of submerged aquatic vegetation (SAV) on turbulence generated in a water column by an oscillating grid turbulence (OGT). Velocity profiles have been measured by an acoustic Doppler velocimeter (MicroADV). Experimental conditions are analysed in two canopy models (rigid and semi-rigid), using nine plant-to-plant distances (ppd), three stem diameters (d), four types of natural SAV (Cladium mariscus, Potamogeton nodosus, Myriophyllum verticillatum and Ruppia maritima) and two oscillation grid frequencies (f). To quantify this response, we have developed a non-dimensional model, with a specific turbulent kinetic energy (TKE), f, stroke (s), d, ppd, distance from the virtual origin to the measurement (zm) and space between grid bars (M). The experimental data show that, at zm/zc power law, zm-2, and does not depend on the vegetation characteristics. In contrast, at zm/zc > 1, TKE decreases faster with zm and scales to the model variables according to TKE/(f·s)∝(·(. Therefore, at zm/zc > 1 the TKE is affected by the geometric characteristics of the plants (both diameter and plant-to-plant distance), an effect called sheltering. Results from semi-rigid canopies and natural SAV are found to scale with the non-dimensional model proposed for rigid canopies. We also discuss the practical implications for field conditions (wind and natural SAV).

  13. Leachates and elemental ratios of macrophytes and benthic algae of an Andean high altitude wetland

    Directory of Open Access Journals (Sweden)

    Beatriz MODENUTTI

    2011-08-01

    Full Text Available In wetlands, macrophytes and filamentous algae constitute an important carbon source for the total content of Dissolved Organic Matter (DOM of the environment. Mallín wetland meadows are highly diverse and rare habitats in Patagonia, that can be characterized as wet meadows with a dense cover mainly dominated by herbaceous plants. We carried out a field study comparing elemental composition (C:N:P of benthic algae (Spirogyra sp. and Zygnema sp. and the submerged macrophyte (Myriophyllum quitense from a high latitude wetland (local name: mallín. Besides we performed laboratory experiments in order to study the effect of ultraviolet radiation (UVR on the optical properties and nutrient release of DOM from leachates of these benthic algae and submerged macrophyte. The obtained results indicated that macrophyte leachates could contribute significantly to changes in the optical characteristics of the wetlands while benthic algae contribute with leachates with low photoreactivity. Finally, nutrient release differs among plant species and season: benthic algae leachates release more P in spring, while M. quitense releases more of this nutrient in autumn. These results suggested that the different colonization may contribute differentially to the chemical environment of the wetland.

  14. The sedimentary sequence from the Lake Ķūži outcrop, central Latvia: implications for late glacial stratigraphy

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    Tiiu Koff

    2011-06-01

    Full Text Available Sediment samples from an outcrop in the near-shore area of Lake Ķūži (Vidzeme Heights, Central Latvia were investigated using palaeobotanical (pollen and macrofossil analysis and lithological (grain-size analysis methods and accelerator mass spectrometry 14C dating. A dark, organic-rich sediment layer was found below 1.7 m of sandy layers approximately 30 cm above the present lake level. Radiocarbon dating of a wood sample from the lowermost layer (11 050 ± 60 14C BP, 13 107–12 721 cal BP shows that the layer is of late glacial age. The composition of the pollen spectra is characterized by Betula nana, Cyperaceae pollen and spores of Equisetum, confirming that the lowermost sediments were formed during the late glacial. Fossils of obligate aquatic organisms in the upper layer, which include oospores of Characeae and seeds of Potamogeton, indicate an open water environment. Pollen of Myriophyllum and Potamogeton and non-pollen palynomorphs, such as algal Botryococcus and Pediastrum cf. boryanum, confirm this conclusion. The pollen assemblage from the greyish loam layer following this lacustrine phase shows a pattern characteristic of the Younger Dryas vegetation before the start of the real expansion of birch forests at the beginning of the Holocene.

  15. 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.

  16. Study on the mercury evolution in a laboratory multi specific aquatic system by using instrumental neutron activation analysis; Estudio de la evolucion del mercurio en un sistema acuatico de laboratorio multiespecifico utilizando analisis por activacion neutronica instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Bubach, Debora; Guevara, Sergio Ribeiro; Arribere, Maria A. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche. Lab. de Analisis por Activacion Nautronica; Pechen de d`Angelo, Ana; Ferrari, Ana; Venturino, Andres [Universidad Nacional del Comahue, Neuquen (Argentina). Facultad de Ingenieria

    1999-11-01

    A preliminary study on the evolution of mercury in the organisms of a laboratory multi specific aquatic system was performed using Instrumental Neutron Activation Analysis (INAA). Some of the possible effects of mercury toxicity were monitored by analyzing early biochemical indicators. The system consisted of an aquarium with bed sediments, aquatic macrophytes (Myriophyllum sp.), bivalves (Diplodom sp.) and exotic fish, simulating a long term contamination situation of unknown causes, where the sediments are the contaminant reservoir. Samples of the abiotic components of the system were analyzed at the beginning of the experiment, and again when the organisms were sampled. Fish carcass, kidney and liver samples, bivalve hepatopancreas, and whole macrophytes were extracted ana analyzed for mercury and other elements by INAA at the beginning of the experiment, and after 48 and 96 hours. Since some crustal elements such as Sc and La were detected in the hepatopancreas and macrophyte samples, enrichment factors for mercury, with respect to the <63 {mu}m sediment fraction, were computed to discriminate the metabolized Hg content from that associated to the particulate. The hepatopancreas index, some indicators of oxidative stress ({gamma}-Glutamyl-cysteinyl-glycine content and lipid peroxidation) and brain acetilcolinesterasa were measured as early indicators of toxicity. (author) 23 refs., 4 tabs.

  17. Characterization of Anaerobic Degradability and Kinetics of Harvested Submerged Aquatic Weeds Used for Nutrient Phytoremediation

    Directory of Open Access Journals (Sweden)

    Takuro Kobayashi

    2014-12-01

    Full Text Available In this study, eight different submerged aquatic species were screened by batch biochemical methane potential and anaerobic degradability tests to identify a promising/suitable feedstock. Kinetics of the best-screened substrate were studied in a mesophilic semi-continuous experiment. The aquatic species Myriophyllum aquaticum, Egeria densa and Potamogeton perfoliatus showed relatively higher methane yields of over 400 NmL/g-VS (volatile solids. Semi-continuous operation was carried out by feeding E. densa for over 400 days. The achieved results were 33%–53% chemical oxygen demand (COD reduction and methane yield of 126–231 NmL/g-VS with a short hydraulic retention time (HRT. Additionally, the NH4+ and PO43− releases from the biomass to water were found to be low (18%–27% and 2.5%–3.9% throughout the experiment. Hydrolysis was the limiting step in the digestion of E. densa, regardless of changes in HRT (15–45 days. The acid-phase model indicated that the hydrolysis rate constant (kh of E. densa was 0.058 one/day, which was one third lower the kh value of food waste, but quite similar to cow manure.

  18. Wastewater canal Vojlovica, industrial complex Pančevo, Serbia – preliminary ecotoxicological assessment of contaminated sediment

    Directory of Open Access Journals (Sweden)

    IVANA PLANOJEVIĆ

    2011-03-01

    Full Text Available Effluents collected from the industrial complex of Pančevo, Serbia (oil refinery, petrochemical plant, and fertilizer factory, are discharged into a wastewater canal entering the Danube River. In this study, which was focused on sediment assessment, a complex triad approach consisting of chemical analysis, sediment toxicity tests and macrozoobenthos community analysis was applied. In toxicity tests on sediment elutriates, the following responses were registered – stimulatory effect in algal bioassay, no effect in acute test with Daphnia magna, and low to moderate toxicity in the conventional Vibrio fischeri test. Moderate to high toxicities were recorded in solid phase tests on Myriophyllum aquaticum and V. fischeri. High content of Hg, certain PAHs and non-characterised sediment contaminants accumulated over years contribute not only to the registered toxicity, but also to the complete absence of macrozoobenthos. The obtained results proved that regularly measured conventional and priority pollutants are hardly ever the only toxic contaminants present in sediments. Toxicity tests, in particular the contact test, might guide towards a better selection of parameters to be regularly or occasionally monitored. In addition, complete sediment toxicity tests proved to be an appropriate method for assessing the bioavailability of the chemically detected contaminants. The analysis of the macrozoobenthos composition and structure as inevitable part of sediment risk assessment procedures integrates the effects of multiple stressors and gives a realistic insight into not only sediment contamination by toxic pollutants, but also the sediment status in general.

  19. Tolerance and hyperaccumulation of a mixture of heavy metals (Cu, Pb, Hg, and Zn) by four aquatic macrophytes.

    Science.gov (United States)

    Romero-Hernández, Jorge Alberto; Amaya-Chávez, Araceli; Balderas-Hernández, Patricia; Roa-Morales, Gabriela; González-Rivas, Nelly; Balderas-Plata, Miguel Ángel

    2017-03-04

    In the present investigation, four macrophytes, namely Typha latifolia (L.), Lemna minor (L.), Eichhornia crassipes (Mart.) Solms-Laubach, and Myriophyllum aquaticum (Vell.) Verdc, were evaluated for their heavy metal (Cu, Pb, Hg, and Zn) hyperaccumulation potential under laboratory conditions. Tolerance analyses were performed for 7 days of exposure at five different treatments of the metals mixture (Cu(+2), Hg(+2), Pb(+2), and Zn(+2)). The production of chlorophyll and carotenoids was determined at the end of each treatment. L. minor revealed to be sensitive, because it did not survive in all the tested concentrations after 72 hours of exposure. E. crassipes and M. aquaticum displayed the highest tolerance to the metals mixture. For the most tolerant species of aquatic macrophytes, The removal kinetics of E. crassipes and M. aquaticum was carried out, using the following mixture of metals: Cu (0.5 mg/L) and Hg, Pb, and Zn 0.25 mg/L. The obtained results revealed that E. crassipes can remove 99.80% of Cu, 97.88% of Pb, 99.53% of Hg, and 94.37% of Zn. M. aquaticum withdraws 95.2% of Cu, 94.28% of Pb, 99.19% of Hg, and 91.91% of Zn. The obtained results suggest that these two species of macrophytes could be used for the phytoremediation of this mixture of heavy metals from the polluted water bodies.

  20. Cyanobacterial toxin elimination via bioaccumulation of MC-LR in aquatic macrophytes: an application of the "Green Liver Concept".

    Science.gov (United States)

    Nimptsch, Jorge; Wiegand, Claudia; Pflugmacher, Stephan

    2008-11-15

    Cyanobacterial blooms and their corresponding toxins are a major concern to human health when surface waters of eutrophicated lakes are the only source for drinking water supply. The aim of the study was to test effective methods for cyanotoxin elimination by using the bioaccumulation potential of aquatic macrophytes in order to reduce microcystin LR (MC-LR) concentrations from raw lake surface water before entering the drinking water plant for further processing. Laboratory assays with aquatic macrophytes were performed in order to assess the most favorable species and optimal biomass for cyanotoxin elimination, where Lemna sp., Myriophyllum sp., and Hydrilla sp. were shown to be the most efficient macrophytes. In a second phase a pilot scale pond system (e.g. replica of the outdoor pond system) was constructed to assess the toxin elimination efficiency of 5.0 g L(-1) biomass of combined macrophytes. The applied macrophytic biomass reduced an initial MC-LR concentration of 12.1 and 9.2 microg L(-1) to values below the WHO guidelines for drinking water of 1.0 microg L(-1) (MC-LR) in only three days. Applying these results in a specially constructed outdoor pond system resulted in > 84% of toxin elimination at an initial concentration of 1.1 microg L(-1) MC-LR within the raw lake water.

  1. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

    Science.gov (United States)

    Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

    1998-01-01

    This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

  2. 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.

  3. Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

    Science.gov (United States)

    Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

    2016-09-01

    Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

  4. Ecological assessment of the macrophytes and phytoplankton in El-Rayah Al-Behery, River Nile, Egypt

    Directory of Open Access Journals (Sweden)

    Amany M. Haroon

    2017-09-01

    Full Text Available The present study aimed to assess the effect of ecological factors on distribution and species composition of macrophytes and phytoplankton communities at El-Rayah Al-Behery. Changes in the quantitative and qualitative composition of the macrophytes and phytoplankton communities were detected in relation to season and sampling site. A total of eleven macrophytes and 100 phytoplankton species were identified. Among the macrophytes, the emergent species Echinochloa stagnina was the most dominant and widely distributed. Phytoplankton community is fairly diverse, related to 7 classes, which contains 3 main classes: Bacillariophyceae (28 taxa, Chlorophyceae (33 taxa and Cyanophyceae (23 taxa. According to statistical analysis, occurrence of most macrophytes species were reversely affected by DO, COD, BOD and PO4; and closely correlated with NO2, NO3, Temp. and pH values. However, nitrogen and phosphorus are considered as limiting factors for bacillariohyceae growth (r = 0.7. Both temperature and pH have a positive effect on the growth of chlorophyceae (r = 0.9 and 0.8, respectively; while dissolved oxygen is an important parameter that affects on the growth of cyanphyceae (r = 0.8. In addition, existence of Myriophyllium spicatum was associated with increasing of bacillariohyceae and total phytoplankton density (r = 0.7. However, the presence of Polygonum tomentosum was intensely related with chlorophyceae (r = 0.9 and Potamogeton nodosus and Polygonum tomentosum were positively correlated with cyanphyceae. In conclusion, the investigated area was characterized by different taxonomic composition of macrophytes and phytoplankton communities, which varied as a result of changing in water physiochemical characteristics as well as the interaction between different species. Keywords: Ecological assessment, Phytoplankton, Macrophytes

  5. Algae mediate submerged macrophyte response to nutrient and dissolved inorganic carbon loading: a mesocosm study on different species.

    Science.gov (United States)

    Xie, Dong; Yu, Dan; You, Wen-Hua; Wang, Li-Gong

    2013-10-01

    Nutrient and dissolved inorganic carbon are two important factors that influence the development and species composition of submerged macrophyte communities in shallow lake ecosystems. Yet little is known about their potential interactive effects on the submerged macrophytes and competition outcome of macrophyte-phytoplankton. We performed a mesocosm experiment to investigate the growth and photosynthetic performance of three submerged macrophytes in relation to phytoplankton/epiphyton with nutrient and bicarbonate enrichment. During the experimental period (42 d), increase in nutrient loading in water column resulted in a substantial burst of phytoplankton and epiphyton growth and increased light attenuation. When combined with nutrient loading, bicarbonate enrichment also resulted in a heavily phytoplankton- and epiphyton-dominated state, although bicarbonate enrichment per se does not cause the phytoplankton and epiphyton growth. However, increase in nutrient loading in water column had significant negative impact on individual performances (growth and photosynthesis) of the three submerged macrophytes and bicarbonate enrichment increased the effect of eutrophication on two dissected-leaf macrophytes (M. spicatum and E. nuttallii). Furthermore, our results also suggest that species-specific photosynthetic performances occurred when submerged macrophytes in an environment with high abundance of phytoplankton/epiphyton. This study highlighted that increase in nutrient loading and bicarbonate in water column is likely to interactively impact both abiotic and biotic properties of a freshwater ecosystem. The interactions of these two factors could select macrophyte species that are able to resist the shading from phytoplankton/epiphyton, making these species more dominant in natural freshwater ecosystems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Perceived health properties of wild and cultivated food plants in local and popular traditions of Italy: A review.

    Science.gov (United States)

    Guarrera, P M; Savo, V

    2013-04-19

    Many wild and cultivated plants are rich in mineral elements and bioactive compounds and are consumed for health purposes. Studies have demonstrated the curative properties of many of these food plants. In this paper, we discuss the properties of several plants with potential health benefits that have previously received little attention. This review provides an overview and critical discussion of food plants perceived by informants (emic view) as healthy or used as 'food medicine' in Italy. Pharmacological activity of these plants is explored, based upon published scientific research (etic view). Preparation methods, taste perception, toxicity and various potentialities of some food plants are also discussed. The present review includes literature available from 1877 to 2012. The information was collected from books, scientific papers, and abstracts that reported any plants used as food medicine in Italy. The perceived health properties were analyzed in the framework of recent international phytochemical and phytopharmacological literature. A total of 67 edible wild plants and 18 cultivated vegetables, distributed into 20 families, were reported by informants (in literature). Several plants were highly cited (e.g., Taraxacum officinale Webb., Crepis vesicaria L., Allium cepa L., Allium sativum L.). The most frequent health properties attributed to edible plants by the informants were: laxative (22 species), diuretic (15), digestive (11), galactagogue (8), antitussive (cough) (8), hypotensive (7), tonic (7), sedative (7), hypoglycemic (6). Some edible plants are promising for their potential health properties, such as Crepis vesicaria L., Sanguisorba minor Scop. and Sonchus oleraceus L. Several wild species were perceived by informants to maintain health but have never been studied from a phytochemical or pharmacological point of view: e.g., Asparagus albus L., Crepis leontodontoides All., Hyoseris radiata L. subsp. radiata, Phyteuma spicatum L. Copyright © 2013

  7. Avaliação comparativa das perdas de água por evapotranspiração em mesocosmos colonizados por diferentes macrófitas aquáticas Comparative evaluation of water losses by evapotranspiration in mesocosms colonized by different aquatic weeds

    Directory of Open Access Journals (Sweden)

    C.S. Rosa

    2009-01-01

    Full Text Available Uma das mais importantes formas de interferência das macrófitas aquáticas em corpos hídricos é o aumento das perdas d'água para a atmosfera pela evapotranspiração. Em alguns corpos hídricos esse aumento pode ser considerado uma interferência negativa e indesejável, especialmente em reservatórios para armazenamento de água e reservatórios de acúmulo para geração de energia elétrica. Assim, este trabalho foi realizado com o objetivo de comparar as perdas d'água em mesocosmos colonizados com macrófitas aquáticas importantes em corpos hídricos no Brasil, mais especificamente Myriophyllum aquaticum, Brachiaria subquadripara, Echinochloa polystachya, Typha latifolia e Pontederia lanceolata. As avaliações foram conduzidas no mês de julho de 2004, em três períodos de quatro dias. As perdas d'água foram avaliadas pelas quantidades necessárias para reposição do nível existente antes do respectivo período de avaliação. A colonização de macrófitas aquáticas aumentou as perdas d'água nos mesocosmos, com maiores valores observados naqueles colonizados por T. latifolia: entre 3,54 e 4,71 vezes a superfície de água sem macrófitas. As perdas nos mesocosmos colonizados por M. aquaticum, B. subquadripara, E. polystachya e P. lanceolata foram estatisticamente similares e promoveram aumentos entre 1,54 e 2,21 vezes a superfície livre. Os resultados evidenciam a importância do manejo de macrófitas aquáticas em corpos hídricos para armazenamento de água.Water loss increase through evapotranspiration is one the most important modes of interference of weeds in water bodies, especially in water storage reservoirs. Thus, this research was conducted to compare the water losses in mesocosms colonized with the aquatic weeds Myriophyllum aquaticum,Brachiaria subquadripara,Echinochloa polystachya,Typha latifolia and Pontederia lanceolata. The evaluations were carried out in July 2004, in three 4-day periods. The water losses

  8. Dinâmica da composição e cobertura de espécies de macrófitas aquáticas e a escolha de indicadores de impacto ambiental em um rio com ecoturismo Composition and coverage dynamics of aquatic macrophytes species and the choose of environmental impact indicators in a river with ecotourism tour

    Directory of Open Access Journals (Sweden)

    Antônio dos Santos Junior

    2011-12-01

    Full Text Available ResumoEstudos sobre ecologia de macrófitas aquáticas em ambiente natural no Brasil são relativamente escassos. Anualmente, um grande número de turistas é recebido para a prática da flutuação nas águas do rio Sucuri, Bonito, Estado de Mato Grosso do Sul. Os objetivos deste estudo foram: (1 descrever a composição e a cobertura relativa das espécies de macrófitas aquáticas no Rio Sucuri, (2 investigar o padrão de desbaste das macrófitas aquáticas no decorrer do ano e (3 eleger espécies com potencial de serem indicadoras de impacto ambiental da atividade turística. Foi empregado o método do intercepto em linha modificado para amostrar a composição e cobertura relativa das espécies de macrófitas aquáticas. Foram identificadas dezessete espécies macrófitas aquáticas. Durante o estudo foram observadas variações na composição e cobertura relativa das espécies de macrófitas aquáticas. Gomphrena elegans Mart. foi a espécie dominante em termos de cobertura relativa. Duas espécies apresentaram as características consideradas importantes para a indicação de impactos da atividade turística, considerando os resultados de cobertura relativa, frequência e desbaste: Nymphaea gardneriana Planch. e Myriophyllum aquaticum (Vell. Verdc. Assim, é sugerido que o monitoramento dos impactos do turismo sobre as macrófitas seja realizado na sua organização biológica populacional.AbstractEcologic studies around aquatic macrophytes in natural environment in Brazil are relatively scarce. Annually, many tourists have been received for floating practice on Sucuri river, in Bonito, Mato Grosso do Sul state. The aims of this research were: (1 describing the composition and the relative coverage of aquatic macrophytes in Sucuri river, (2 investigating the pattern of thinning of aquatic macrophytes during the year, and (3 electing species, such as indicators of environmental impact done by tourism. Intercept line method modified was

  9. Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

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    Senze Magdalena

    2015-03-01

    Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

  10. Using aquatic vegetation to remediate nitrate, ammonium, and soluble reactive phosphorus in simulated runoff.

    Science.gov (United States)

    Moore, M T; Locke, M A; Kröger, R

    2016-10-01

    Within the agriculturally-intensive Mississippi River Basin of the United States, significant conservation efforts have focused on management practices that reduce nutrient runoff into receiving aquatic ecosystems. Only a small fraction of those efforts have focused on phytoremediation techniques. Each of six different aquatic macrophytes were planted, in monoculture, in three replicate mesocosms (1.2 m × 0.15 m × 0.65 m). Three additional unvegetated mesocosms served as controls for a total number of 21 mesocosms. Over two years, mesocosms were amended once each summer with sodium nitrate, ammonium sulfate, and potassium phosphate dibasic to represent nitrogen and phosphorus in agricultural runoff. System retention was calculated using a simple aqueous mass balance approach. Ammonium retention in both years differed greatly, as Panicum hemitomon and Echinodorus cordifolius retentions were significantly greater than controls in the first year, while only Myriophyllum aquaticum and Typha latifolia were significantly greater than controls in the second year. Greater soluble reactive phosphorus retention was observed in T. latifolia compared to controls in both years. Several other significant differences were observed in either the first or second year, but not both years. In the first year's exposure, P. hemitomon was significantly more efficient than the control, Saururus cernuus, and T. latifolia for overall percent nitrate decrease. Results of this novel study highlight inherent variability within and among species for nutrient specific uptake and the temporal variations of species for nutrient retention. By examining this natural variability, scientists may design phytoremediation systems with greater impact on improving agricultural runoff water quality. Published by Elsevier Ltd.

  11. Does Nature and Persistence of Substrate at a Mesohabitat Scale Matter for Chironomidae Assemblages? a Study of Two Perennial Mountain Streams in Patagonia, Argentina

    Science.gov (United States)

    Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

    2012-01-01

    Chironomid substrate—specific associations regarding the nature (organic—inorganic) and stability (stable—unstable) of different habitats were investigated at two low order Patagonian streams, during high and low water periods. Nant y Fall and Glyn rivers were visited twice (October 2007 and March 2008) and seven different habitat types were identified. A total of 60 samples were collected using a Surber sampler (0.09 m -2 and 250 µm) and a set of 23 environmental descriptors including physicochemical parameters and different fractions of particulate organic matter were assessed. 35 Chironomidae taxa were recorded with Orthocladiinae (20), Chironominae (7), and Podonominae (4) being the most well—represented subfamilies. Paratrichocladius sp. 1, Parapsectrocladius sp. 2, Parametriocnemus sp. 1, Pseudochironomus sp., and Rheotanytarsus sp. were the most abundant taxa. According to the relative preference index, at least 14 taxa showed strong affinity for a particular substrate. The structurally complex macrophyte Myriophyllum quitense supported 11 taxa compared with only five taxa found on the less complex Isoetes savatieri. Generally, stable substrates (boulders, cobbles, and rooted plants) supported significantly higher chironomids richness, abundance, and diversity than unstable ones (gravel—sand). Canonical correspondence analysis revealed that detritus (leaves, seeds, and biomass), macrophyte biomass, and secondarily hydraulic variables had high explanatory power on chironomids species composition and structure. This work suggests that more complex substrates showing persistence in the temporal dimension supported a diverse array of chironomids, meaning that the maintenance of natural habitat heterogeneity is essential for the community. Land—use practices having significant effects on ecological stream attributes such as increased turbidity, sediment deposition, and runoff patterns will alter assemblages. Understanding environmental associations

  12. 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.

  13. Ecological characteristics of plankton and aquatic vegetation in Lake Qiluhu.

    Science.gov (United States)

    Mingming, Hu; Huaidong, Zhou; Yuchun, Wang; Yingcai, Wang; Zhen, Wang; Weiju, Wu; Gaofeng, Zhao; Yao, Cheng; Yongding, Liu

    2014-01-01

    Investigations of the phytoplankton, zooplankton, zoobenthos and aquatic vegetation in Lake Qiluhu were carried out in February, 2009. Over the whole lake, 13 sampling sites were set up for the analysis of phytoplankton and zooplankton, and 22 profiles for the collection of macrophytes and zoobenthos. In the survey, 7 phyla, 65 algae species were identified. The average abundance of phytoplankton was 7.16 × 10(8) cells/L, and the dominant specie was Limnothrix redekei. No obvious surface accumulation of algae was detected. The concentration of Chlorophyll a ranged from 85 to 101 μg/L, and the average value was 93 μg/L. Nineteen species of zooplankton were observed, including 4 species of rotifers, 6 species of cladocerans and 9 species of copepods. Copepods were the dominant species, their abundance reaching 68%, whilst Cladocerans took second place with an abundance proportion of 28%. Six species of submerged vegetation were identified: Potamogeton Pectinatus, Myriophyllum, Elodea Canadensis, Ceratophyllum demersum and Potamogeton crispus. Amongst them, the dominant vegetation was P. Pectinatus, the biomass of which was up to 63% of the total biomass. Emerged macrophytes were cluster distributed across the whole lake, mainly consisting of Scirpus tabernaemontani, phragmites communis and cane shoots. Unfortunately, no living zoobenthos were found at the sites. The results indicated that, in Lake Qiluhu, the abundance of phytoplankton was maintained at a high level. The ecological function of submerged vegetation was gradually being lost because of its low standing crop and coverage, and the benthic animal habitat was severely damaged.

  14. Analysis of heavy metal flow in the river Przemsza, Katowice region, using macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Lewander, M.

    1995-06-01

    The river Przemsza, in southern Poland, was investigated with the aim to determine the flow of Cd, Pb and Zn between the submerged macrophytes Potamogeton pectinatus and Myriophyllum verticillatum, sediment and water, and to find out if a pollution gradient was present along the investigated part of the river. In order to determine the uptake of heavy metals from water and sediment macrophytes were planted in pots along the river, in unpolluted and polluted sediment during six weeks in the summer of 1993. After harvesting the plants were dried, wet digested and analysed by atomic absorption spectrophotometry. Parallel in situ experiments and outdoor experiments in sealed jars were performed. No significant decreased pollution gradient in the sediment or the macrophytes content could be detected. However, the water concentration of Zn decreased slightly along the gradient and in both experiments Pb concentration in the water also decreased. The concentrations of metals in the plants and sediments were probably depending on local stream conditions as well as increasing organic content. The study suggests that the macrophytes took up metals both from water and sediment. The unpolluted sediment accumulated Pb and Zn in both experiments, while Cd was accumulated in the in situ experiment. Metal concentration in the polluted sediment decreased during the study period, either due to plant uptake or loss to the water. Metals lost from the polluted sediment to the water were taken up by the plant shoots. Lead mainly accumulated in the roots while Zn accumulated in the plant shoots, and Cd was distributed almost equally between shoots and roots. 18 refs, 2 figs, 6 tabs

  15. Analyzing the effects of four submerged macrophytes with two contrasting architectures on zooplankton: A mesocosm experiment

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    Lei Zeng

    2017-08-01

    Full Text Available Increases in the structural complexity of submerged macrophytes are often shown to be linked to higher invertebrate abundance and diversity, but a number of studies have demonstrated, however, that this is not always the case. The objective of this study was to analyze the effects of four macrophyte species with two contrasting architectures (simple architecture with broad leaves: Vallisneria spiralis L. and Potamogeton malaianus Miq. and complex architecture with finely dissected leaves: Ceratophyllum demersum L. and Myriophyllum verticillatum L. on zooplanktons. We hypothesized that structurally more complex macrophytes would support more zooplanktons and higher diversity, species richness, abundance and biomass, and to test our hypotheses, zooplankton samples within the above-mentioned macrophytes were collected to analyze the variances at different times. Contrary to our expectations, we found that the zooplankton’ responses were independent to the macrophyte architecture. Specially, although finely dissected M. verticillatum could significantly increase total zooplanktons, diversity, species richness, rotifers and cladocerans than the other three macrophytes, the effects of finely dissected C. demersum on these parameters exhibited no significant differences compared to two broad leaved macrophytes (V. spiralis and P. malaianus. Moreover, broad leaved macrophytes even increased more abundance zooplanktons than finely dissected C. demersum. In addition, the effects of macrophytes on zooplanktons also varied with zooplankton species. For example, the four tested macrophytes could significantly increase cladoceran abundance and biomass. Yet for copepods, the density was significantly increased in presence of V. spiralis and C. demersum, but P. malaianus and M. verticillatum did not show significant effects on copepod density. Moreover, all the tested macrophytes except for V. spiralis even significantly suppress copepod biomass. Therefore

  16. Metalaxyl toxicity, uptake, and distribution in several ornamental plant species.

    Science.gov (United States)

    Wilson, P C; Whitwell, T; Klaine, S J

    2001-01-01

    Phytoremediation depends on the ability of plants to tolerate and assimilate contaminants. This research characterized the interaction between several ornamental plant species and the fungicidal active ingredient, metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester]. Species evaluated included sweetflag (Acorus gramineus Sol. ex Aiton), canna (Canna hybrida L. 'Yellow King Humbert'), parrotfeather [Myriophyllum aquaticum (Vell.) Verdc.], and pickerelweed (Pontederia cordata L.). Metalaxyl tolerance levels for each species were determined by exposing plants for 7 d to solutions containing 0, 5, 10, 25, 50, 75, or 100 mg metalaxyl L-1 aqueous nutrient media. Response endpoints included fresh mass production after 7 d exposure and 7 d post-exposure and quantum efficiency using dark-adapted (Fv/Fm) and light-adapted (fluorescence yields) plants. Metalaxyl uptake and distribution within the plant was determined by growing plants in aqueous nutrient media containing 1.18 x 10(6) Bq L-1 [14C]metalaxyl (0.909 mg L-1) for 1, 3, 5, or 7 d. Plant tissues were combusted and analyzed by liquid scintillation counting. Metalaxyl had no effects on the endpoints measured, except for fresh mass production of sweetflag at the 75 and 100 mg L-1 treatment levels. However, leaf necrosis was apparent in most species after 5 d exposure to concentrations greater than 25 mg L-1. Metalaxyl removal from the spiked nutrient media ranged from 15 to 60% during the 7-d exposure period. The majority of metalaxyl removed from the solution was detected within individual plants. In nearly all cases, activity from the radiolabeled pesticide accumulated in the leaves. Uptake of metalaxyl was correlated with water uptake throughout the 7 d. These results suggest that all species examined may be good candidates for incorporation into a phytoremediation scheme for metalaxyl.

  17. Association of a Specific Algal Group with Methylmercury Accumulation in Periphyton of a Tropical High-Altitude Andean Lake.

    Science.gov (United States)

    Lanza, William G; Achá, Darío; Point, David; Masbou, Jeremy; Alanoca, Lucia; Amouroux, David; Lazzaro, Xavier

    2017-01-01

    Periphyton relevance for methylmercury (MeHg) production and accumulation are now well known in aquatic ecosystems. Sulfate-reducing bacteria and other microbial groups were identified as the main MeHg producers, but the effect of periphyton algae on the accumulation and transfer of MeHg to the food web remains little studied. Here we investigated the role of specific groups of algae on MeHg accumulation in the periphyton of Schoenoplectus californicus ssp. (Totora) and Myriophyllum sp. in Uru Uru, a tropical high-altitude Bolivian lake with substantial fishing and mining activities accruing around it. MeHg concentrations were most strongly related to the cell abundance of the Chlorophyte genus Oedogonium (r (2) = 0.783, p = 0.0126) and to no other specific genus despite the presence of other 34 genera identified. MeHg was also related to total chlorophyll-a (total algae) (r (2) = 0.675, p = 0.0459), but relations were more significant with chlorophyte cell numbers, chlorophyll-b (chlorophytes), and chlorophyll-c (diatoms and dinoflagellates) (r (2) = 0.72, p = 0.028, r (2) = 0.744, p = 0.0214, and r (2) = 0.766, p = 0.0161 respectively). However, Oedogonium explains most variability of chlorophytes and chlorophyll-c (r (2) = 0.856, p = < 0.001 and r (2) = 0.619, p = 0.002, respectively), suggesting it is the most influential group for MeHg accumulation and periphyton algae composition at this particular location and given time.

  18. Traditional herbal medicine in Far-west Nepal: a pharmacological appraisal

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    Shrestha Keshab P

    2010-12-01

    Full Text Available Abstract Background Plant species have long been used as principal ingredients of traditional medicine in far-west Nepal. The medicinal plants with ethnomedicinal values are currently being screened for their therapeutic potential but their data and information are inadequately compared and analyzed with the Ayurveda and the phytochemical findings. Methods The present study evaluated ethnomedicinal plants and their uses following literature review, comparison, field observations, and analysis. Comparison was made against earlier standard literature of medicinal plants and ethnomedicine of the same area, the common uses of the Ayurveda and the latest common phytochemical findings. The field study for primary data collection was carried out from 2006-2008. Results The herbal medicine in far-west Nepal is the basis of treatment of most illness through traditional knowledge. The medicine is made available via ancient, natural health care practices such as tribal lore, home herbal remedy, and the Baidhya, Ayurveda and Amchi systems. The traditional herbal medicine has not only survived but also thrived in the trans-cultural environment with its intermixture of ethnic traditions and beliefs. The present assessment showed that traditional herbal medicine has flourished in rural areas where modern medicine is parsimoniously accessed because of the high cost and long travel time to health center. Of the 48 Nepalese medicinal plants assessed in the present communication, about half of the species showed affinity with the common uses of the Ayurveda, earlier studies and the latest phytochemical findings. The folk uses of Acacia catechu for cold and cough, Aconitum spicatum as an analgesic, Aesculus indica for joint pain, Andrographis paniculata for fever, Anisomeles indica for urinary affections, Azadirachta indica for fever, Euphorbia hirta for asthma, Taxus wallichiana for tumor control, and Tinospora sinensis for diabetes are consistent with the latest

  19. Enzyme inhibitory and antioxidant activities of traditional medicinal plants: Potential application in the management of hyperglycemia

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    Gulati Vandana

    2012-06-01

    Full Text Available Abstract Background Traditional Indian and Australian medicinal plant extracts were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of hyperglycemia and type 2 diabetes. The antioxidant activities were also assessed. Methods The evaluation of enzyme inhibitory activity of seven Australian aboriginal medicinal plants and five Indian Ayurvedic plants was carried out against α-amylase and α-glucosidase. Antioxidant activity was determined by measuring (i the scavenging effect of plant extracts against 2, 2-diphenyl-1-picryl hydrazyl (DPPH and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS and (ii ferric reducing power. Total phenolic and total flavonoid contents were also determined. Results Of the twelve plant extracts evaluated, the highest inhibitory activity against both α-amylase and α-glucosidase enzymes was exerted by Santalum spicatum and Pterocarpus marsupium with IC50 values of 5.43 μg/ml and 0.9 μg/ml, respectively, and 5.16 μg/ml and 1.06 μg/ml, respectively. However, the extracts of Acacia ligulata (IC50 = 1.01 μg/ml, Beyeria leshnaultii (0.39 μg/ml, Mucuna pruriens (0.8 μg/ml and Boerhaavia diffusa (1.72 μg/ml exhibited considerable activity against α-glucosidase enzyme only. The free radical scavenging activity was found to be prominent in extracts of Acacia kempeana, Acacia ligulata followed by Euphorbia drummondii against both DPPH and ABTS. The reducing power was more pronounced in Euphorbia drummondii and Pterocarpus marsupium extracts. The phenolic and flavonoid contents ranged from 0.42 to 30.27 μg/mg equivalent of gallic acid and 0.51 to 32.94 μg/mg equivalent of quercetin, respectively, in all plant extracts. Pearson’s correlation coefficient between total flavonoids and total phenolics was 0.796. Conclusion The results obtained in this study showed that most of the plant extracts

  20. Macrophytes may not contribute significantly to removal of nutrients, pharmaceuticals, and antibiotic resistance in model surface constructed wetlands.

    Science.gov (United States)

    Cardinal, Pascal; Anderson, Julie C; Carlson, Jules C; Low, Jennifer E; Challis, Jonathan K; Beattie, Sarah A; Bartel, Caitlin N; Elliott, Ashley D; Montero, Oscar F; Lokesh, Sheetal; Favreau, Alex; Kozlova, Tatiana A; Knapp, Charles W; Hanson, Mark L; Wong, Charles S

    2014-06-01

    Outdoor shallow wetland mesocosms, designed to simulate surface constructed wetlands to improve lagoon wastewater treatment, were used to assess the role of macrophytes in the dissipation of wastewater nutrients, selected pharmaceuticals, and antibiotic resistance genes (ARGs). Specifically, mesocosms were established with or without populations of Typha spp. (cattails), Myriophyllum sibiricum (northern water milfoil), and Utricularia vulgaris (bladderwort). Following macrophyte establishment, mesocosms were seeded with ARG-bearing organisms from a local wastewater lagoon, and treated with a single pulse of artificial municipal wastewater with or without carbamazepine, clofibric acid, fluoxetine, and naproxen (each at 7.6μg/L), as well as sulfamethoxazole and sulfapyridine (each at 150μg/L). Rates of pharmaceutical dissipation over 28d ranged from 0.073 to 3.0d(-1), corresponding to half-lives of 0.23 to 9.4d. Based on calculated rate constants, observed dissipation rates were consistent with photodegradation driving clofibric acid, naproxen, sulfamethoxazole, and sulfapyridine removal, and with sorption also contributing to carbamazepine and fluoxetine loss. Of the seven gene determinants assayed, only two genes for both beta-lactam resistance (blaCTX and blaTEM) and sulfonamide resistance (sulI and sulII) were found in sufficient quantity for monitoring. Genes disappeared relatively rapidly from the water column, with half-lives ranging from 2.1 to 99d. In contrast, detected gene levels did not change in the sediment, with the exception of sulI, which increased after 28d in pharmaceutical-treated systems. These shallow wetland mesocosms were able to dissipate wastewater contaminants rapidly. However, no significant enhancement in removal of nutrients or pharmaceuticals was observed in mesocosms with extensive aquatic plant communities. This was likely due to three factors: first, use of naïve systems with an unchallenged capacity for nutrient assimilation and

  1. Late Miocene (Pannonian) Vegetation from the Northern Part of Central Paratethys

    Science.gov (United States)

    Kováčová, M.; Doláková, N.

    2009-04-01

    During Late Miocene, the Western Carpathian paleogeography started to change. The Lake Pannon retreated southwards, and the northern coast of the back arc basin was slightly elevated due to progradation of deltaic and alluvial facies, especially in the lowlands. The studied „Pannonian lake" sediments come from the Czech and Slovak parts of Central Paratethys. Changes of the sedimentary environment from deep to shallow lake and deltaic environment, followed by development of alluvial plains were noticed. Salinity crisis due to Paratethys isolation led to development of total freshwater environment to the end of this period. Samples from 3 surficial localities and 15 boreholes were palynologically studied. Occasional occurences of Dinoflagellates indicate a slightly higher salinity, whereas green algae Pediastrum, aquatic ferns Azolla, and aquatic and coastal plants (Nelumbo, Nymphaea, Myriophyllum, Sparganium, Potamogeton, Cyperaceae etc.) represent a freshwater environment. Due to paleogeographic changes and climatic oscillations the number of thermophilous taxa decreased and some of them disappeared completely from this area (f. e. Sapotaceae, Palmae). Mostly broad-leaved deciduous elements of mixed mesophytic forests (Quercus, Celtis, Carya, Tilia, Carpinus, Betula, Juglans) with some thermophilous elements admixture of Engelhardia, Castanea, Trigonobalanopsis, Symplocos, Cornaceaepollis satzveyensis generally dominate. Variously high relief of the uplifted mountainy chains created ideal conditions for higher presence of extrazonal vegetation (Cedrus, Tsuga, Picea, Cathaya) in the investigated area. Zonal type of vegetation including marshes, riparian forests with Alnus, Salix, Pterocarya, Liquidambar, Betula, Fraxinus, shrubs and lianas on dryer substrates associated riparian forest (Buxus, Ericaceae, Vitaceae, Lonicera, Rosaceae type Rubus), and coastal swamps with Taxodiaceae, Nyssa, Myrica, Sciadopitys were growing in the floodplain lowlands of Vienna Basin

  2. Functional diversity of macrophyte communities within and between Pyrenean lakes

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    Enric BALLESTEROS

    2009-02-01

    Full Text Available Submersed vegetation is a common feature in about 70% Pyrenean high mountain (>1500 m a.s.l. lakes. Isoetids and soft-water elodeids are common elements of this underwater flora and can form distinct vegetation units (i.e. patches of vegetation dominated by different species within complex mosaics of vegetation in shallow waters (<7 m. Since isoetids exert a strong influence on sediment biogeochemistry due to high radial oxygen loss, we examined the small scale characteristics of the lake environment (water and sediment associated to vegetation patches in order to ascertain potential functional differences among them. To do so, we characterised the species composition and biomass of the main vegetation units from 11 lakes, defined plant communities based on biomass data, and then related each community with sediment properties (redox and dissolved nutrient concentration in the pore water and water nutrient concentration within plant canopy. We also characterised lake water and sediment in areas without vegetation as a reference. A total of twenty-one vegetation units were identified, ranging from one to five per lake. A cluster analysis on biomass species composition suggested seven different macrophyte communities that were named after the most dominant species: Nitella sp., Potamogeton praelongus, Myriophyllum alterniflorum, Sparganium angustifolium, Isoetes echinospora, Isoetes lacustris and Carex rostrata. Coupling between macrophyte communities and their immediate environment (overlying water and sediment was manifested mainly as variation in sediment redox conditions and the dominant form of inorganic nitrogen in pore-water. These effects depended on the specific composition of the community, and on the allocation between above- and belowground biomass, and could be predicted with a model relating the average and standard deviation of sediment redox potential from 0 down to -20 cm, across macrophyte communities. Differences in pore

  3. Predicting aquatic macrophyte occurrence in soft-water oligotrophic lakes (Pyrenees mountain range

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    Cristina Pulido

    2014-08-01

    Full Text Available Distribution of aquatic macrophytes in lakes is related to geographical, morphological, catchment and water chemistry variables as well as human impacts, which modify the original environment. Here, we aim at building statistical models to establish the ecological niches of 11 aquatic macrophytes (10 different phanerogams and the genus Nitella from oligotrophic soft-water lakes and infer their ecological requirements and environmental constraints at the southernmost limit of their distribution. Macrophyte occurrence and environmental variables were obtained from 86 non-exploited oligotrophic soft-water lakes from the Pyrenees (Southern Europe; 42º50´N, 1º00´E; macrophytes inhabited 55 of these lakes. Optimum ranges and macrophyte occurrence were predicted in relation to 18 geographical, morphological, catchment and water chemistry variables using univariate and multivariate logistic models. Lakes at low altitude, in vegetated catchments and with low water concentration of NO3- and SO4-2, were the most suitable to host macrophytes. In general, individual species of aquatic macrophytes showed clear patterns of segregation along conductivity and pH gradients, although the specific combination of variables selected in the best models explaining their occurrence differed among species.  Based on the species response to pH and conductivity, we found Isoetes lacustris have its optimum in waters with low conductivity and pH (i.e. negative monotonic response. In contrast, Callitriche palustris, Ranunculus aquatilis, Subularia aquatica, Nitella spp., and Myriophyllum alterniflorum showed an optimum at intermediate values (i.e. unimodal response, whereas Potamogeton berchtoldii, Potamogeton alpinus, and Ranunculus trichophyllus as species had their optimum at relatively high water pH and conductivity (i.e. positive monotonic response. This pattern has been observed in other regions for the same species, although with different optima and tolerance

  4. CHOICE OF MACROPHYTE SUBSTRATE IN THE USE OF DIATOMS AS INDICATORS OF POND WATER QUALITY ASSESSMENT: PRELIMINARY DATA ON THE CASE OF ALALAY POND (COCHABAMBA, BOLIVIA

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    Eduardo A. Morales

    2012-06-01

    Full Text Available Alalay Pond is a 230-hectare, shallow aquatic ecosystem within Cochabamba, the third largest city in Bolivia. With the aim to determine the suitability of epiphytic diatoms for water quality assessment in the pond and to choose a substrate that would hold a representative bioindicator epiphytic community, the macrophytes Schoenoplectus californicus subsp. tatora (Kunth T. Koyama, Typha dominguensis Pers., Myriophyllum verticillatum L. and Azolla filiculoides Lam. were selected and differences in diatom community composition and structure were tested. Diatoms were collected during four sampling campaigns in the March-September, 2011 period, from three stations contiguous to the pelagic zone and prepared for analysis using standard, internationally used protocols. In all, 27 samples were collected from which 28 taxa characteristic of eutrophic environments were identified and 17 others could not be assigned names from the literature. Although many of the species are shared among sampling sites, the epiphytic communities developing at each station were different in structure and composition. Although, there are marked temporal variations in community features on each of the macrophytes, Shannon-Wiener and Pielou indexes, as well as canonical correspondence analysis, showed no marked differences within a single campaign and station among the 4 macrophytes. Shifts in structure and composition are denoted less commonly by species replacement and more often by changes in percent relative abundance of dominant and rare species. Very few species are restricted to a station or seem to show strong preference for a particular substrate. Taking into account growth, structural and ecological characteristics, as well as some phenological features of the macrophytes, S. californicus subsp. tatora and T. dominguensis are the most suitable substrates for water quality assessments in the pond. As demonstrated by multivariate analyses, among-site and time

  5. Inibição da mineralização de compostos nitrogenados de lixiviado de macrófita aquática: adequação metodológica = Inhibition of the mineralization of nitrogen compounds in leachate from aquatic macrophytes: methodological adequacy

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    Maíra de Figueiredo Nunes

    2008-04-01

    Full Text Available Este estudo visou estabelecer as concentrações adequadas da nitrapirina para a inibição das demandas de oxigênio produzidas pelas oxidações dos compostos nitrogenados durante a mineralização aeróbia de lixiviado, utilizando a macrófita aquática Myriophyllumaquaticum como fonte de matéria orgânica dissolvida (MOD. Para tanto, realizaram-se incubações com lixiviado com diferentes tratamentos: (i tratamento com MOD, (ii tratamento com MOD + nitrapirina em diferentes concentrações (10; 25 e 50 mg L-1,visando encontrar a concentração que inibisse o processo de nitrificação, (iii tratamento com MOD + NH4SO2, (iv tratamento com MOD + NH4SO2 + nitrapirina, e (v tratamento com MOD + azida. A partir destas incubações, foram efetuadas medições periódicas da quantidade de oxigênio dissolvido destes tratamentos. Os resultados indicaram que a proporção de 10 mg L-1 de nitrapirina para cada 10 mg C de lixiviado é eficaz para inibir a oxidação dos compostos nitrogenados de lixiviados de macrófitas aquáticas.This study aimed to establish the adequate concentrations of nitrapyrin for the effective inhibition of oxygen demandrequired for the oxidation of nitrogen compounds during aerobic mineralization of leachate. The aquatic macrophyte Myriophyllum aquaticum was used as a source of dissolved organic matter (DOM. The leachate was incubated in several chambers, containing different composition and treatments: (i treatment with leachate (DOM, (ii treatment with DOM plus nitrapyrin in different concentrations (10; 25 and 50 mg L-1, aiming at finding the right concentration that inhibits the nitrification process, (iii treatment withDOM plus NH4SO2, (iv treatment containing DOM and nitrapyrin plus NH4SO2, and (v treatment with DOM plus azide. The dissolved oxygen amount in each incubation treatment was periodically measured. The results indicated that the ratio of 10 mg L-1 of nitrapyrin for each 10 mg C of leachate is efficient in

  6. The role of anthropogenic water reservoirs within the landscapes of mining areas – a case study from the western part of the Upper Silesian Coal Basin

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    Jaruchiewicz Ewelina

    2014-03-01

    Full Text Available A few thousand anthropogenic water reservoirs can be found in the area of the Upper Silesian Coal Basis (USCB located in southern Poland. In this paper the role of such anthropogenic lakes in the landscape of the western part of the USCB was presented and illustrated with the example of Knurów, a mining city, and its immediate surrounding area. The study of landscape changes in this area was carried out on the basis of archival and contemporary cartographic materials, historical sources, and interviews with inhabitants and direct field observations. It was found that the origin of the majority of the water reservoirs is related to hard coal, clay and sand mining. They were created primarily as a result of filling subsidence basins and post-mining excavations with water, as well as being the result of the construction of various hydro-technical facilities (settling ponds, fire protection water reservoirs, etc. In the study area the anthropogenic water reservoirs are of different sizes, shapes and durability and play different roles in the environment. Between 1884 and 2001 their number increased 25-fold, while at the same time their total surface area increased more than 8-fold. The role of the newly created water reservoirs in the landscape primarily involves the transformation of the existing terrestrial ecosystems into wetland ecosystems. The agro-forestry landscape of the late 19th century was transformed into a typically anthropogenic landscape with a dominant share of water reservoirs, settlement ponds and mining waste heaps. The most common species of plants around the water reservoirs are Phragmites australis, Typha latifolia, Ceratophyllum demersum, Elodea canadensis, Potamogeton natans, Lemna sp., Acorus calamus, Myriophyllum verticillatum, Sagittaria sagittifolia, Alisma plantago-aquatica and Glyceria aquatica. The most valuable elements of the flora include Trapa natans and Ruppia maritima, species recognized in Poland as threatened

  7. Woodland caribou persistence and extirpation in relic populations on Lake Superior

    Directory of Open Access Journals (Sweden)

    Arthur T. Bergerud

    2007-04-01

    Full Text Available Extended: The hypothesis was proposed that woodland caribou (Rangifer tarandus caribou in North America had declined due to wolf predation and over-hunting rather than from a shortage of winter lichens (Bergerud, 1974. In 1974, two study areas were selected for testing: for the lichen hypothesis, we selected the Slate Islands in Lake Superior (36 km2, a closed canopy forest without terrestrial lichens, wolves, bears, or moose; for the predation hypothesis, we selected the nearby Pukaskwa National Park (PNP where terrestrial lichens, wolves, bears, and moose were present. Both areas were monitored from 1974 to 2003 (30 years. The living and dead caribou on the Slates were estimated by the ‘King census’ strip transect (mean length 108±9.3 km, extremes 22-190, total 3026 km and the Lincoln Index (mean tagged 45±3.6, extremes 15-78. The mean annual population on the Slate Islands based on the strip transects was 262±22 animals (extremes 104-606, or 7.3/km2 (29 years and from the Lincoln Index 303±64 (extremes 181-482, or 8.4/km2 (23 years. These are the highest densities in North America and have persisted at least since 1949 (56 years. Mountain maple (Acer spicatum interacted with caribou density creating a record in its age structure which corroborates persistence at relatively high density from c. 1930. The mean percentage of calves was 14.8±0.34% (20 years in the fall and 14.1±1.95% (19 years in late winter. The Slate Islands herd was regulated by the density dependent abundance of summer green foods and fall physical condition rather than density independent arboreal lichen availability and snow depths. Two wolves (1 wolf/150 caribou crossed to the islands in 1993-94 and reduced two calf cohorts (3 and 4.9 per cent calves while female adult survival declined from a mean of 82% to 71% and the population declined ≈100 animals. In PNP, caribou/moose/wolf populations were estimated by aerial surveys (in some years assisted by telemetry

  8. Pleistocene lake level changes in Western Mongolia

    Science.gov (United States)

    Borodavko, P. S.

    2009-04-01

    lake is 75 km long and 31 km wide. Its mean depth is 47 m, with the deepest point reaching 80 m, and its total water volume is 66,034 km3 and drainage basin 115,500 km2. The only water flowing into it is Galbiyn Hooloi. Hara-Us Nur Lake is a fresh-water (mineralization ca 107-348 mg/l, pH -7.8) basin situated in the Mongolian Great Lakes Depression [2]. Hara-Us Nur is fed by the Kobdo and Buyant rivers, which start in the Mongolian Altay, and outflows via the Chano-Hairkhan River into Hara-Us Nur Lake. Hara-Us Nur is divided by the Ak-Bashi Island into two subbasins. It has a water area of 1857 km2 with a length of 72.2 km and a maximum width of 27 km [4]. The maximum depth is 4 m and the average depth is ca 2 m [5,6]. The terraced lake shores are covered by steppe and desert vegetation. Pharagmites is abundant in the river deltas and close to the shore-line and the shallow-water littoral is covered by rich aquatic vegetation, including Myriophyllum verticulatum, Zannichelia pedunculata, Utricularia vulgaris [3]. Hara-Nur Lake is situated in the desert steppe subzone of the Mongolian Great Lakes Depression. The fresh-water Hara-Nur Lake receives inflow from Hara-Us Nur Lake via the Chano-Hairkhan River. There are two outflows from the lake one outflow is via a 10 km-long channel which flows to the Dzabhan River, which in turn flows into the closed Hyargas Lake. The other outflow is a small semi-permanent stream with flows southward into the closed brackish-water Dorgon Lake. Hara-Nur has a water area of 57,500 ha, with a length of 37 km and a maximum width of ca 24 km. The maximum depth is 7 m and the average depth is ca 4 m. The mean water mineralization is 260 mg/l and the pH is 8.0 [5]. The catchment area is ca 7,200,000 ha. Lake Ureg located in the Mongolian Altay at an altitude of 1425 m.a.s.1., this lake has an area 237.6 km2 and maximum depth of 48 m. Secchi disk transparency is to 8 m. Macrophyte beds cover up to 20 per cent of the lake area, with the common