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Sample records for submersed aquatic macrophytes

  1. Competition between two submersed aquatic macrophytes, Potamogeton pectinatus and Potamogeton gramineus, across a light gradient

    Science.gov (United States)

    Submersed aquatic macrophyte communities, are often limited by the availability of light. Thus, they offer a unique opportunity to evaluate competition when light is the limiting resource. Competitive abilities of Potamogeton pectinatus (L.) Börner and Potamogeton gramineus L. were estimated using a...

  2. 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

  3. 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

  4. Stress protein synthesis and peroxidase activity in a submersed aquatic macrophyte exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Siesko, M.M.; Grossfeld, R.M. [North Carolina State Univ., Raleigh, NC (United States); Fleming, W.J. [National Biological Service, Raleigh, NC (United States). North Carolina Cooperative Fish and Wildlife Research Unit

    1997-08-01

    Sago pondweed (Potamogeton pectinatus L.) was exposed to CdCl{sub 2} to evaluate peroxidase (POD) activity and stress protein (SP) synthesis as potential biomarkers of contaminant stress in an aquatic plant. Peroxidase activity did not increase in sago pondweed incubated for 24 h in a liquid culture medium containing 0.5, 0.75, or 1 mM CdCl{sub 2}. By contrast, at each of these CdCl{sub 2} concentrations, SPs of 162, 142, 1122, 82, and 61 kDa were preferentially synthesized, and synthesis of a 66-kDa protein was reduced relative to controls. Peroxidase activity also did not change in sago pondweed rooted for 21 d in agar containing 1 mM CdCl{sub 2}, despite the lower growth rate, lower protein content, and brown discoloration of the plants. Only when the plants were grown 7 or 21 d on agar containing 10 mM CdCl{sub 2} were the growth retardation and phenotypic deterioration accompanied by significantly increased POD activity. In contrast, plants rooted for 7 d in agar containing 1 mM CdCl{sub 2} were not significantly discolored or retarded in growth, yet they preferentially synthesized SPs of 122, 82, and 50 kDa and synthesized proteins of 59 and 52 kDa at reduced rates relative to controls. Similar changes in protein synthesis were accompanied by signs of depressed growth after 21 d of incubation with 1 mM CdCl{sub 2} and with 7 or 21 d of exposure to 10 mM CdCl{sub 2}. These data indicate that changes in SP synthesis may precede detectable alterations in growth of aquatic plants and, therefore, may be a potentially useful early biomarker of contaminant stress. However, further studies will be required to determine whether the SP response is measurable during exposure to environmentally relevant contaminant levels.

  5. 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.

  6. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  7. Macrophytes: Ecology of aquatic plants

    NARCIS (Netherlands)

    Bornette, G.; Puijalon, S.

    2009-01-01

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

  8. Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.I.

    1979-01-01

    Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

  9. Phytoremediation potential of aquatic macrophyte, Azolla.

    Science.gov (United States)

    Sood, Anjuli; Uniyal, Perm L; Prasanna, Radha; Ahluwalia, Amrik S

    2012-03-01

    Aquatic macrophytes play an important role in the structural and functional aspects of aquatic ecosystems by altering water movement regimes, providing shelter to fish and aquatic invertebrates, serving as a food source, and altering water quality by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The ability to hyperaccumulate heavy metals makes them interesting research candidates, especially for the treatment of industrial effluents and sewage waste water. The use of aquatic macrophytes, such as Azolla with hyper accumulating ability is known to be an environmentally friendly option to restore polluted aquatic resources. The present review highlights the phytoaccumulation potential of macrophytes with emphasis on utilization of Azolla as a promising candidate for phytoremediation. The impact of uptake of heavy metals on morphology and metabolic processes of Azolla has also been discussed for a better understanding and utilization of this symbiotic association in the field of phytoremediation.

  10. Aquatic Insects Associated with Submerged Macrophytes with Different Morphological Complexities

    Directory of Open Access Journals (Sweden)

    Douglas F Peiró

    2013-06-01

    Full Text Available The aim of the study was to analyze the diversity and community structure of aquatic insects associated with species of submersed macrophytes with different morphological complexity in relation to leaf structure. Sampling occurred in raining and dry periods at Ribeirão das Anhumas, Américo Brasiliense/SP. Four macrophytes were analyzed: Vallisneria sp., Eleocharis sp., Egeria najas and Ottelia sp. The entomological community was identified up to the family level, and at tribe level for Chironomidae. The community structure was analyzed using diversity indices of Simpson, Equitability evenness, relative participation of functional category and taxa dominance. The dispersion of faunal composition between the different collection periods was analyzed using a n-MDS with Morisita index. The structure of the insect community associated with macrophytes with different structural morphologies was analyzed using structural similarity calculated by the Bray-Curtis index. Seventeen families were identified from five orders, a total of 1642 specimens. The family Hydropsychidae (Trichoptera presented eudominance (52.6%, followed by the tribe Pentaneurini (Chironomidae (13.8% and family Trichoryithidae (Ephemeroptera (10%. The results showed that there were no large diversity variations in the analyzed macrophyte species and the sampling periods. The predator and collector functional groups were predominant. The n-MDS analysis indicated the absence of seasonal variation and, the similarity analysis indicated that macrophyte E. najas and Otellia sp., presented similar fauna structure, differing from other analyzed species. The results demonstrated that the morphological structure of macrophytes may have different structures of aquatic insect communities.

  11. Assessing Environmental Impact on Aquatic Macrophyte Species ...

    African Journals Online (AJOL)

    Assessing Environmental Impact on Aquatic Macrophyte Species Structure in a Near Coastal Tropical River, Southeastern Nigeria. ... Eighteen physico-chemical parameters were sampled and analyzed using standard and analytical methods of water analysis. Generated databases obtained were subjected to statistical ...

  12. Effects of Convective Hydraulic Circulation on Phosphorus Transport in Aquatic Macrophyte Beds

    Science.gov (United States)

    1993-02-01

    transect was established in the vegetated region of the northwest bay, along the slope of the basin, using posts driven into the sediment at 10-m...volume, but also because of the presence of vegetation . Submersed aquatic macrophytes contribute significantly to the development of thermal...temperate reservoir," Hydro- biologia 215,231-241. James, W. F., and Barko, J. W. (1991). "Estimation of phosphorus exchange between Oittoral and pelagic

  13. Management of Half Moon Lake, Wisconsin, for Improved Native Submersed Macrophyte Growth

    Science.gov (United States)

    2010-05-01

    for aesthetic and recreational reasons. Eutrophication can negatively impact submersed macrophyte growth and community diversity by stimulating...sediments in the lake are high (range = 2.3 to 11.7 mg·m-2·d-1) and, thus, represent an important nutritional source to this species. During the July

  14. Aquatic arsenic: phytoremediation using floating macrophytes.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-04-01

    Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumulating plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

    Science.gov (United States)

    Davies, Jo; Dobbs, Michael; Ebke, Peter; Hanson, Mark; Hommen, Udo; Knauer, Katja; Loutseti, Stefania; Maltby, Lorraine; Mohr, Silvia; Poovey, Angela; Poulsen, Véronique

    2010-01-01

    Introduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species because of differences in the duration and mode of exposure; sensitivity to the specific toxic mode of action of the chemical; and species-specific traits (e.g., duckweed's very short generation time). Discussion and perspectives These topics were addressed during the workshop entitled “Aquatic Macrophyte Risk Assessment for Pesticides” (AMRAP) where a risk assessment scheme for aquatic macrophytes was proposed. Four working groups evolved from this workshop and were charged with the task of developing Tier 1 and higher-tier aquatic macrophyte risk assessment procedures. Subsequently, a SETAC Advisory Group, the Macrophyte Ecotoxicology Group (AMEG) was formed as an umbrella organization for various macrophyte working groups. The purpose of AMEG is to provide scientifically based guidance in all aspects of aquatic macrophyte testing in the laboratory and field, including prospective as well as retrospective risk assessments for chemicals. As AMEG expands, it will begin to address new topics including bioremediation and sustainable management of aquatic macrophytes in the context of ecosystem services. PMID:20191396

  16. Checklist of the Aquatic Macrophytes

    African Journals Online (AJOL)

    aquatic plants colonize the fresh water bodies in. Nigeria with Jebba Lake as a case study. Nigerian water bodies are of high economic importance to the riparian populace and other stakeholders that depend on such water bodies for their economic activities. It is therefore essential to monitor and manage the influx of these ...

  17. Fish Diversity in Relation to Aquatic Macrophytes and ...

    African Journals Online (AJOL)

    An investigation of fish diversity in relation to aquatic macrophytes and physicochemical parameters of Ona Lake in Asaba was carried out within a period of eighteen months. Fish samples were collected fortnightly from three sampling sites using cast, gill and trigger nets. Aquatic macrophytes found in close association with ...

  18. Environmental study of some metals on several aquatic macrophytes

    African Journals Online (AJOL)

    Aquatic macrophytes can be used in the study of quality of water ecosystems and in monitoring of metals and other pollutants. This study was focused on assessment of metals accumulation in certain aquatic macrophytes (biomonitors), in comparison with water and sediment (abiotic monitors) of the lake. Concentrations of ...

  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. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    Science.gov (United States)

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Performance assessment of aquatic macrophytes for treatment of municipal wastewater

    OpenAIRE

    Shah, Mumtaz,; Hashmi, Hashim Nisar; Ali, Arshad; Ghumman, Abdul Razzaq

    2014-01-01

    The objective of the study was to evaluate the performance of three different aquatic macrophytes for treatment of municipal wastewater collected from Taxila (Pakistan). A physical model of treatment plant was constructed and was operated for six experimental runs with each species of macrophyte. Every experimental run consist of thirty days period. Regular monitoring of influent and effluent concentrations were made during each experimental run. For the treatment locally available macrophyte...

  2. Arsenic accumulation by edible aquatic macrophytes.

    Science.gov (United States)

    Falinski, K A; Yost, R S; Sampaga, E; Peard, J

    2014-01-01

    Edible aquatic macrophytes grown in arsenic (As)-contaminated soil and sediment were investigated to determine the extent of As accumulation and potential risk to humans when consumed. Nasturtium officinale (watercress) and Diplazium esculentum (warabi) are two aquatic macrophytes grown and consumed in Hawaii. Neither has been assessed for potential to accumulate As when grown in As-contaminated soil. Some former sugarcane plantation soils in eastern Hawaii have been shown to have concentrations of total As over 500 mg kg(-1). It was hypothesized that both species will accumulate more As in contaminated soils than in non-contaminated soils. N. officinale and D. esculentum were collected in areas with and without As-contaminated soil and sediment. High soil As concentrations averaged 356 mg kg(-1), while low soil As concentrations were 0.75 mg kg(-1). Average N. officinale and D. esculentum total As concentrations were 0.572 mg kg(-1) and 0.075 mg kg(-1), respectively, corresponding to hazard indices of 0.12 and 0.03 for adults. Unlike previous studies where watercress was grown in As-contaminated water, N. officinale did not show properties of a hyperaccumulator, yet plant concentrations in high As areas were more than double those in low As areas. There was a slight correlation between high total As in sediment and soil and total As concentrations in watercress leaves and stems, resulting in a plant uptake factor of 0.010, an order of magnitude higher than previous studies. D. esculentum did not show signs of accumulating As in the edible fiddleheads. Hawaii is unique in having volcanic ash soils with extremely high sorption characteristics of As and P that limit release into groundwater. This study presents a case where soils and sediments were significantly enriched in total As concentration, but the water As concentration was below detection limits. © 2013 Published by Elsevier Inc.

  3. Classifying aquatic macrophytes as indicators of eutrophication in European lakes

    NARCIS (Netherlands)

    Penning, W.E.; Mjelde, M.; Dudley, B.; Hellsten, S.; Hanganu, J.; Kolada, A.; van den Berg, Marcel S.; Poikane, S.; Phillips, G.; Willby, N.; Ecke, F.

    2008-01-01

    Aquatic macrophytes are one of the biological quality elements in the Water Framework Directive (WFD) for which status assessments must be defined. We tested two methods to classify macrophyte species and their response to eutrophication pressure: one based on percentiles of occurrence along a

  4. Aquatic Macrophytes and Their Impact on Water Quality of Lekan ...

    African Journals Online (AJOL)

    Survey of Aquatic Plants of Lekan Aare, South West Nigeria was carried out between May and August 2005. The aquatic ... The Families Cyperaceae and Poaceae topped the list by having 4 species each while the others had 1 species each. ... Key words: Aquatic plants, Lekan Aare Lake, Macrophytes, South West Nigeria.

  5. Local ciliate communities associated with aquatic macrophytes.

    Science.gov (United States)

    Yeates, Anna M; Esteban, Genoveva F

    2014-03-01

    This study, based within the catchment area of the River Frome, an important chalk stream in the south of England, compared ciliated protozoan communities associated with three species of aquatic macrophyte common to lotic habitats: Ranunculus penicillatus subsp. pseudofluitans, Nasturtium officinale and Sparganium emersum. A total of 77 ciliate species were counted. No species-specific ciliate assemblage was found to be typical of any one plant species. Ciliate abundance between plant species was determined to be significantly different. The ciliate communities from each plant species were unique in that the number of species increased with ciliate abundance. The community associated with R. penicillatus subsp. pseudofluitans showed the highest consistency and species richness whereas S. emersum ciliate communities were unstable. Most notably, N. officinale was associated with low ciliate abundances and an apparent reduction in biofilm formation, discussed herein in relation to the plant's production of the microbial toxin phenethyl isothiocyanate. We propose that the results reflect differences in the quantity and quality of biofilm present on the plants, which could be determined by the different plant morphologies, patterns of plant decay and herbivore defense systems, all of which suppress or promote the various conditions for biofilm growth.

  6. Oligochaeta (Annelida: Clitellata associated to aquatic macrophytes in Brazil

    Directory of Open Access Journals (Sweden)

    Nathalie Aparecida de Oliveira Sanches

    2016-09-01

    Full Text Available Oligochaeta are still characterized as a poorly studied group among the aquatic macroinvertebrates and few studies about their ecology were conducted in Brazil. Thus, our study aimed to provide an overview of the association between Oligochaeta and macrophytes, in Brazilian continental aquatic environments, by means of a literature review along with an inventory of species associated to aquatic macrophytes on marginal lagoons in the reservoir Ribeirão das Anhumas (Américo Brasiliense, São Paulo, Brazil. In the review, we analyzed 10 articles, where we obtained data on 41 species. We also sampled 5 macrophyte genera, Egeria, Salvinia, Utricularia, Eleocharis, and Ceratophyllum, in August and December 2012 and in March and April 2013, in the reservoir Ribeirão das Anhumas. We registered 21 Oligochaeta species associated to these macrophytes. With the data obtained in the review along with the inventory of the reservoir Ribeirão das Anhumas, we found a total of 41 species associated to aquatic macrophytes, with a higher richness of the Naididae family (93.33%, followed by Opistocystidae (4.44%, and Alluroididae (2.22%. Our study inventoried about 48% of the Oligochaeta diversity registered in continental ecosystems in Brazil, thus highlighting the significance of macrophytes as a resource for these invertebrates, mainly for the Naididae family.

  7. Aquatic macrophyte diversity of the Pantanal wetland and upper basin

    Directory of Open Access Journals (Sweden)

    VJ. Pott

    Full Text Available This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz Morrone & Zuloaga.

  8. Aquatic macrophyte diversity of the Pantanal wetland and upper basin.

    Science.gov (United States)

    Pott, V J; Pott, A; Lima, L C P; Moreira, S N; Oliveira, A K M

    2011-04-01

    This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga.

  9. Aquatic macrophytes : restore, eradicate or is there a compromise?

    NARCIS (Netherlands)

    Nes, van E.H.; Scheffer, M.; Berg, van den S.; Coops, H.

    2002-01-01

    Promoting indigenous submerged macrophytes is considered an important measure to restore shallow lakes. On the other hand, dense stands of aquatic vegetation often cause nuisance for boating, swimming and by obstruction of water flow. Consequently, the interests of recreational users may conflict

  10. Environmental study of some metals on several aquatic macrophytes

    African Journals Online (AJOL)

    Administrator

    2011-09-26

    Sep 26, 2011 ... 1Faculty of Science, Departmant of Biology and Ecology, University in Kragujevac, Serbia. 2Faculty of Science, Department of Mathematics and Informatics, University in Kragujevac, Serbia. Accepted 27 May, 2011. Aquatic macrophytes can be used in the study of quality of water ecosystems and in ...

  11. Linking carbon and nitrogen metabolism to depth distribution of submersed macrophytes using high ammonium dosing tests and a lake survey.

    Science.gov (United States)

    Yuan, Guixiang; Cao, Te; Fu, Hui; Ni, Leyi; Zhang, Xiaolin; Li, Wei; Song, Xin; Xie, Ping; Jeppesen, Erik

    2013-12-01

    Strategies of carbon (C) and nitrogen (N) utilisation are among the factors determining plant distribution. It has been argued that submersed macrophytes adapted to lower light environments are more efficient in maintaining C metabolic homeostasis due to their conservative C strategy and ability to balance C shortage. We studied how depth distributions of 12 submersed macrophytes in Lake Erhai, China, were linked to their C-N metabolic strategies when facing acute [Formula: see text] dosing.[Formula: see text] dosing changed C-N metabolism significantly by decreasing the soluble carbohydrate (SC) content and increasing the [Formula: see text]-N and free amino acid (FAA) content of plant tissues.The proportional changes in SC contents in the leaves and FAA contents in the stems induced by [Formula: see text] dosing were closely correlated (positive for SC and negative for FAA) with the colonising water depths of the plants in Lake Erhai, the plants adapted to lower light regimes being more efficient in maintaining SC and FAA homeostasis.These results indicate that conservative carbohydrate metabolism of submersed macrophytes allowed the plants to colonise greater water depths in eutrophic lakes, where low light availability in the water column diminishes carbohydrate production by the plants.

  12. Studies on heavy metal accumulation in aquatic macrophytes from Sevan (Armenia) and Carambolim (India) lake systems

    Digital Repository Service at National Institute of Oceanography (India)

    Vardanyan, L.G.; Ingole, B.S.

    Aquatic macrophytes are unchangeable biological filters and they carry out purification of the water bodies by accumulating dissolved metals and toxins in their tissue. In view of their potential to entrap several toxic heavy metsls, 45 macrophytes...

  13. Ammonium, microcystins, and hypoxia of blooms in eutrophic water cause oxidative stress and C-N imbalance in submersed and floating-leaved aquatic plants in Lake Taihu, China.

    Science.gov (United States)

    Zhang, Meng; Wang, Zhengqi; Xu, Jun; Liu, Yaqin; Ni, Leyi; Cao, Te; Xie, Ping

    2011-01-01

    The heavy bloom of cyanobacteria is a disastrous consequence of freshwater eutrophication, and the bloom is highly toxic due to its secondary metabolites called microcystins (MCs). The release of organic substances from dense blooms causes an increase in NH4+ and decrease in oxygen in lake water. In the present study, the dynamics of physio-biochemical responses of five aquatic macrophytes to MCs and NH4+ stresses in Meiliang Bay were evaluated. The bay is one of the most seriously eutrophized areas dominated by the toxic cyanobacteria of Lake Taihu, China. The results demonstrate that aquatic macrophytes in Meiliang Bay are subjected to successive external stresses. From January to May, they are subjected to high NH4+ stress (>0.56 mg L(-1)), whereas from June to September or during dense blooms, the macrophytes experience both MC proliferation and moderate NH4+ toxicity (>0.3 mg L(-1)). In August, high NH4+ stress occurs along with hypoxia stress, whereas from September to December, the macrophytes experience moderate NH4+ stress, causing a serious imbalance in C-N metabolism and oxidative stress. Between the two aquatic plant life forms, floating-leaved plants are more resistant to the stresses of eutrophication than are submersed plants. Elevated MCs in the water column can aggravate oxidative stress and suppress the soluble protein contents of aquatic plants. High NH4+ in the water causes severe C and N imbalance in submersed macrophytes because of considerable carbon consumption for free amino acid synthesis. The superoxide dismutase activities of submersed macrophytes are suppressed by low light penetrating the eutrophic water, which might impair the antioxidative function of the plants. The findings of this study provide mainly field evidence that reveals the physical, chemical, and biological stresses on aquatic plants in bloom-prevailed eutrophic lakes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Mechanical strength of stems in aquatic macrophytes

    Directory of Open Access Journals (Sweden)

    Katarzyna Bociąg

    2011-01-01

    Full Text Available In populations of submerged macrophytes, individuals are selected in terms of resistance to the effect of hydrodynamic forces. The aim of this study was to check whether individuals growing in river water are more tensile and bending resistant than plants occurring in places not exposed to flow stress. We determined the ultimate tensile strength of stems in four macrophyte species, Potamogeton natans, P. pectinatus, Batrachium fluitans and Chara fragilis, which occur in two environmental variants: in running (current velocity of 0.1-0.6 m/s-1 and stagnant water. In addition, flexure of P. natans stems from both environmental variants was examined. What is more, the type and arrangement of strengthening structures in stems of the plants under study were determined. Potamogeton natans stems are the most resistant to stretching (15.6±4.7 N, while stems of P. pectinatus (3.3±1.0 N and Batrachium fluitans (2.6±0.8 N are less resistant. Chara fragilis (0.6±0.3 N has the least resistant stems. Batrachium, Chara and P. pectinatus are more resistant to stretching if they occur in a river current, whereas P. natans, in stagnant lake water. Ultimate bending moment of P. natans stems from lakes is also much greater than of stems from a river (9.75•10-3 – 4.25•10-3 Nm as compared to 2.12•10-3 – 1.00•10-3 Nm. The resistance of stems to breaking is directly proportional to the stem and thallus cross sectional areas. On the one hand, in all the studied Cormophyta species, the more resistant stems (in P. natans from stagnant water, in the others from running water are thicker and characterised by a higher contribution of air spaces in the overall stem cross-section. On the other hand, the stems retain their species specific structure and have a similar proportion of strengthening elements.

  15. Synergy between shading and herbivory triggers macrophyte loss and regime shifts in aquatic systems

    NARCIS (Netherlands)

    Hidding, Bert; Bakker, Elisabeth S.; Hootsmans, Michiel J. M.; Hilt, Sabine

    2016-01-01

    Macrophytes play a keystone role in shallow aquatic ecosystems. In lakes, macrophytes stabilize clear-water conditions with high biodiversity and their decline can cause a shift to a turbid state with lower biodiversity. Various mechanisms have been suggested as triggers of macrophyte collapse.

  16. Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication

    Directory of Open Access Journals (Sweden)

    Suelen Cristina Alves da Silva

    2014-06-01

    Full Text Available AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i through two‑way ANOVAs considering the stand extent (m and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand; and ii through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.

  17. Anaerobic decomposition of a native and an exotic submersed macrophyte in two tropical reservoirs

    Directory of Open Access Journals (Sweden)

    WA Chiba de Castro

    Full Text Available Some aquatic plants have fast metabolism and growth, even at sub-optimal conditions, and become dominant in lentic environments such as large reservoirs, altering the nutrient cycle and impairing their environmental quality. There is great need in the knowledge impact processes of invasive species in aquatic environments, among the major, those related to the decomposition. This study evaluated the anaerobic decomposition of invasive submerged macrophytes Egeria densa Planch, native, and Hydrilla verticillata (L.f. Royle, exotic in Porto Primavera and Jupiá reservoirs, Paraná basin. We evaluated the decay of organic matter, humification degree of the leached material, electrical conductivity and pH of the decomposition process. Mathematical models were utilised to describe the decomposition patterns over time. Both species showed the same heterogeneous pattern of decay of organic matter and carbon mineralisation. The models of carbon mineralisation, compared with the experimentally obtained data presented were adequate. Both species show no significant differences in the decomposition processes. Incubations of both species presented rapid t ½ for POC mineralisation and low DOC mineralisation.

  18. Physical and chemical properties of substrates produced using macrophytes aquatics

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2013-12-01

    Full Text Available Aquatic macrophytes are widely used as bioindicators of water quality because their proliferation usually occurs in eutrophic water sources and has hit several parts of Brazil and the world, restricted the multiple uses of aquatic ecosystems. However, this group of plants is able to retain considerable amounts of nutrients, presenting high productivity and high growth rate, thus, a good source of biomass for use in the production of substrates. In order to evaluate the potential of aquatic macrophytes water hyacinth (Eichhornia crassipes Solms., water lettuce (Pistia stratiotes L. and cattail (Typha domingensis Pers. in the production of substrates was performed in this work, the physical and chemical characterization and evaluation of the degree of humification. The treatments were arranged in a 3 × 4 factorial, completely randomized design with three replications. All substrates produced with 100% macrophyte density present within the limits of 400 kg m-3, considered ideal. The composite substrates with water hyacinth and water lettuce are with the electrical conductivity of 0,79 a 2,49 dS m-1 within recommended. organic compounds produced are considered mature and have high levels of nitrogen phosphorus and potassium; The substrate produced with 70% water lettuce +30 % dung and 70% composed of cattail manure +20% +10% topsoil and 70 +30% cattail manure have C/N ratio within the considered ideal; the humification ratio and humification index, except for the four treatments (70 % water lettuce manure +30%, 5 (100% water hyacinth and 8 (70% water hyacinth manure +30% are within the considered ideal, the percentage of humic acids and polymerization rate, except for treatments 1 (100% water lettuce and 12 (100% cattail, are shown below the ideal.

  19. Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

    Directory of Open Access Journals (Sweden)

    Henry-Silva Gustavo Gonzaga

    2006-01-01

    Full Text Available The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants. Water samples were collected from the: (i fish pond source water, (ii effluent from fish pond and (iii effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively and total nitrogen removal (46.1% and 43.9%, respectively than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen and the control (50.3% total phosphorus and 22.8% total nitrogen, indicating that the treated effluents may be reused in the aquaculture activity.

  20. Effects of aquatic macrophytes on the limnology and utilization of ...

    African Journals Online (AJOL)

    Qualitative sampling of the macrophytes, invertebrates fauna attached to the macrophytes and physico-chemical parameters of Moro reservoir was undertaken to study the effects of the macrophytes on the limnology and utilization of the reservoir and its resources. Eight species of macrophytes were recorded with ...

  1. 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

  2. ISSUES IN DIGITAL IMAGE PROCESSING OF AERIAL PHOTOGRAPHY FOR MAPPING SUBMERSED AQUATIC VEGETATION

    Science.gov (United States)

    The paper discusses the numerous issues that needed to be addressed when developing a methodology for mapping Submersed Aquatic Vegetation (SAV) from digital aerial photography. Specifically, we discuss 1) choice of film; 2) consideration of tide and weather constraints; 3) in-s...

  3. Potential for phosphate mitigation from agricultural runoff by three aquatic macrophytes

    Science.gov (United States)

    Phosphate from agricultural runoff is considered a contributor to eutrophication. Three aquatic macrophyte species, Leersia oryzoides, Typha latifolia, and Sparganium americanum, were investigated for their phosphate mitigation ability. Mesocosms were exposed to flowing phosphate enriched water (1...

  4. Can biophysical properties of submersed macrophytes be determined by remote sensing?

    Energy Technology Data Exchange (ETDEWEB)

    Malthus, T.J. [Univ. of Edinburgh (United Kingdom); Ciraolo, G.; La Loggia, G. [Univ. of Palermo, Sicily (Italy)] [and others

    1997-06-01

    This paper details the development of a computationally efficient Monte Carlo simulation program to model photon transport through submersed plant canopies, with emphasis on Seagrass communities. The model incorporates three components: the transmission of photons through a water column of varying depth and turbidity; the interaction of photons within a submersed plant canopy of varying biomass; and interactions with the bottom substrate. The three components of the model are discussed. Simulations were performed based on measured parameters for Posidonia oceanica and compared to measured subsurface reflectance spectra made over comparable seagrass communities in Sicilian coastal waters. It is shown that the output is realistic. Further simulations are undertaken to investigate the effect of depth and turbidity of the overlying water column. Both sets of results indicate the rapid loss of canopy signal as depth increases and water column phytoplankton concentrations increase. The implications for the development of algorithms for the estimation of submersed canopy biophysical parameters are briefly discussed.

  5. Wetland and aquatic macrophytes as indicators of anthropogenic hydrologic disturbance

    Science.gov (United States)

    Wilcox, Douglas A.

    1995-01-01

    Hydrologic disturbance can affect wetland and aquatic macrophyte communities by creating temporal changes in soil moisture or water depth. Such disturbances are natural and help maintain wetland diversity; however, anthropogenic changes in wetland hydrology may have negative effects on wetlands. Since plant communities respond to habitat alterations, observations of plant-community changes may be used to recognize effects of hydrologic disturbances that are otherwise not well understood. A number of plants, including Typha angustifolia (narrow-leaf cattail) and Lythrum salicaria (purple loosestrife), are recognized as disturbance species; they are often found in roadside ditches, in wetlands that have been partially drained, or in low areas that have been flooded. Other species commonly occur on mudflats exposed by lowering of water levels. In addition, wetland shrubs and trees invade or die as a result of draining or flooding. In more subtle terms, the relative composition of plant communities can change without the addition or loss of species, and zonation patterns may develop or change as a result of altered hydrology. Remote sensing (photointerpretation) and field vegetation studies, coupled with monitoring of water levels, are recommended for gaining an understanding of hydrologic disturbances in wetlands.

  6. Impacts of aquatic macrophytes configuration modes on water quality.

    Science.gov (United States)

    Liu, Jiakai; Liu, Jinglan; Zhang, Rong; Zou, Yuqi; Wang, Huihui; Zhang, Zhenming

    2014-01-01

    Constructed wetland technology is regarded as an important ecological restoration technology and used widely in sewage disposal. In order to give them a wider scope of application and to improve their performance in water restoration, the current experiment was designed. Four aquatic macrophytes (dwarf cattail (TM), yellow-flowered iris (WI), water shallot (ST) and watermifoil (MS)) were picked and planted in artificial floating islands (AFIs) in different configurations (TM + WI, ST + MS and TM + WI + MS) and two patterns, radiation pattern (RP) and annular pattern (AP), for a 60-day experiment. Then, water quality and growth were monitored every 10 days. The results indicate that the different configurations performed diversely on waste water purification. First, a composite plant configuration removed more pollutant than a single one with the same total increment of biomass. Second, the plant configuration of MS + ST was most effective in total nitrogen (TN), total phosphorus (TP) or PO4(3-) removal, and TM + IW + MS was good at chemical oxygen demand (COD) and NO3(-) removal. However, different patterns comprised from the same species had a certain effect on absorption of pollutants. Generally speaking, plant configurations with a RP were better than an AP in purification. Accordingly, these provided the methods for the pollution wetland restoration.

  7. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza-Quinones, F.R. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)], E-mail: f.espinoza@terra.com.br; Rizzutto, M.A.; Added, N.; Tabacniks, M.H. [Physics Institute, University of Sao Paulo, Rua do Matao s/n, Travessa R 187, 05508-900 Sao Paulo, SP (Brazil); Modenes, A.N.; Palacio, S.M.; Silva, E.A.; Rossi, F.L.; Martin, N.; Szymanski, N. [Department of Chemical Engineering - Postgraduate Program - NBQ, West Parana State University, Rua da Faculdade, 645, Jardim Santa Maria, 85903-000 Toledo, Parana (Brazil)

    2009-04-15

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr{sup 6+} mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

  8. PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

    Science.gov (United States)

    Espinoza-Quiñones, F. R.; Rizzutto, M. A.; Added, N.; Tabacniks, M. H.; Módenes, A. N.; Palácio, S. M.; Silva, E. A.; Rossi, F. L.; Martin, N.; Szymanski, N.

    2009-04-01

    The uptake of hexavalent chromium in free living floating aquatic macrophytes Eicchornia crassipes cultivated in non-toxic chromium-doped hydroponic solutions is presented. A Cr-uptake bioaccumulation experiment was carried out using healthy macrophytes grown in a temperature controlled greenhouse. Six samples of nutrient media and plants were collected during the 23 day experiment. Roots and leaves were acid digested with the addition of an internal Gallium standard, for thin film sample preparation and quantitative Cr analysis by PIXE method. The Cr 6+ mass uptake by the macrophytes reached up to 70% of the initial concentration, comparable to former results and literature data. The Cr-uptake data were described using a non-structural first order kinetic model. Due to low cost and high removal efficiency, living aquatic macrophytes E. crassipes are a viable biosorbent in an artificial wetland of a water effluent treatment plant.

  9. Seasonal occurrence and distribution of submerged aquatic macrophytes in the tidal Potomac River

    Science.gov (United States)

    Haramis, G.M.; Carter, V.; Gammon, P.; Hupp, C.

    1979-01-01

    A systematic survey was conducted in the Tidal Potomac River in 1978 to determine the presence, abundance, and phenology of submersed aquatic macrophytes. The survey covered 81.5 km of main river and 59.3 km of tributary on the Maryland shore. Four regions were selected for the study: (1) Piscataway - Mattawoman Creek region (fresh-tidal river), (2) Nanjemoy Creek-Port Tobacco River region (transition zone), (3) Wicomico River region (estuary), and (4) St. Marys River region (estuary). The Wicomico River region was subdivided into fresh tidal river, transition zone and estuary for purposes of date analysis. Data were gathered by sampling each 15 m along transects running perpendicular to shore for a maximum distance of 300 m. Modified oyster tongs were used to sample both plants and benthic soils from an outboard boat. A total of 131 transects were established with a total of approximately 3500 grabs being taken per sampling period. Sampling was initiated in the spring and repeated in the summer and fall. Highest plant diversity and productivity were measured in the transition zone extending from Lower Cedar Point to beyond Maryland Point, a distance of approximately 30 km, and in the transition zone of the Wicomico River above Chaptico Bay. Fresh tidal areas were devoid of plants. The estuary had a sparse growth of horned pondweed (Zannichellia palustris) and widgeon grass (Ruppia maritima) in the spring: horned pondweed was not found in summer or fall. Redhead grass (Potomageton perfoliatus) was the most abundant pondweed; it matured in early summer and died back in mid-to-late summer. Wild celery (Vallisneria americana) and widgeon grass matured in early-to-late fall and were the most abundant plants during that period. Data analysis is being finalized and a publication is in preparation. This research will be continued over the next several seasons as part of the long term USGS effort on the Potomac

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

    Science.gov (United States)

    1984-11-01

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

  11. A Simulation Model on the Competition for Light of Meadow-forming and Canopy-forming Aquatic Macrophytes at High and Low Nutrient Availability

    National Research Council Canada - National Science Library

    Best, Elly

    2004-01-01

    A simulation model has been developed that focuses on the ability of two competing submersed macrophytes, meadow-forming and canopy-forming, to maintain their biomass under different environmental conditions...

  12. A Submersed Macrophyte Index of Condition for the Upper Mississippi River

    Science.gov (United States)

    Portions of the Upper Mississippi River are listed as impaired for aquatic life use under section 303(d) of the United States Clean Water Act by the State of Minnesota’s Pollution Control Agency and Wisconsin’s Department of Natural Resources for exceeding turbidity and eutrophic...

  13. Spatial and temporal relationships between the invasive snail Bithynia tentaculata and submersed aquatic vegetation in Pool 8 of the Upper Mississippi River

    Science.gov (United States)

    Weeks, Alicia M.; DeJager, Nathan R.; Haro, Roger J.; Sandland, Greg J.

    2017-01-01

    Bithynia tentaculata is an invasive snail that was first reported in Lake Michigan in 1871 and has since spread throughout a number of freshwater systems of the USA. This invasion has been extremely problematic in the Upper Mississippi River as the snails serve as intermediate hosts for several trematode parasites that have been associated with waterfowl mortality in the region. This study was designed to assess the abundance and distribution of B. tentaculata relative to submersed aquatic vegetation as macrophytes provide important nesting and food resources for migrating waterfowl. Temporal changes in both vegetation and snail densities were compared between 2007 and 2015. Between these years, B. tentaculata densities have nearly quadrupled despite minor changes in vegetation abundance, distribution and composition. Understanding the spatial distribution of B. tentaculata in relation to other habitat features, including submersed vegetation, and quantifying any further changes in the abundance and distribution of B. tentaculata over time will be important for better identifying areas of risk for disease transmission to waterfowl.

  14. Long-term Simulation Study about the Impact of submerse Macrophytes on thermal Stratification Dynamics and Transport Processes in an extreme shallow water lake - Lake Federsee

    Science.gov (United States)

    Wolf, Thomas; Pöschke, Franziska; Pflugbeil, Thomas

    2017-04-01

    Lake Federsee is formed primarily by ice age processes and was subjected to strong siltation processes in post-glacial times, while in the last two centuries anthropogenic impact due to amelioration projects became more important and determined it's morphometry. Lake Federsee has a maximum length of 2.4 km, a maximum width of 1.1 km and an area of approx. 1.4 km2. With respect to it's area Lake Federsee is the third largest lake in the federal state of Baden-Wuerttemberg situated in the south of Germany. It is characterized by its very flat bathymetry with a maximum depth of about 3.15 m and an average depth of about 1 m. In recent years Lake Federsee has undergone a strong reduction of the nutrient content, thus developing from hypertrophic states in the years 1980ies to eutrophic conditions in the years 2000ies. Since 2005 this development is accompanied by a change of the general habitus of the lake converting from a lake dominated by algae to a lake dominated by macrophytes. Changing successions of aquatic plants have been observed in the lake with strong seasonal variations in the composition and density of the vegetation cover, however forming often an almost complete coverage of the lake. In the present study the implementation of the hydrodynamic, three-dimensional model DELFT3D - FLOW for this extreme shallow water lake will be presented. The impact of some numerical parameters will be investigated in a sensitivity study, which is aiming to set up the hydrodynamic model in an optimal way. This 3-dim hydrodynamic model is used to simulate the 3-dim flow field and to investigate the thermal stratification as well as the mixing processes taking place in this lake. The model is run for the simulation time period 2000 - 2016 having a horizontal resolution of dx=dy=50 m and 10 or 20 equidistantly spaced fixed vertical layers giving a vertical resolution of 0.32 or 0.16 m respectively. The timestep is choosen to be dt = 10 s. Analysis of the simulated vertical

  15. Aquatic macrophyte composition of some tropical tin-mined ponds in ...

    African Journals Online (AJOL)

    A survey of aquatic macrophytes was conducted for nine tin-mined lakes located around Jos in September 1998 and February 1999 to coincide with the wet and dry season conditions. A total of 48 species were found in all ponds, 46 species classified into 14 families for the wet season and 24 species classified into 11 ...

  16. Clonal variation in the thermal response of the submerged aquatic macrophyte Potamogeton pectinatus

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.

    2002-01-01

    Broadly distributed plants have to cope with dramatic differences across latitude in the prevailing environmental temperature. We investigated the effect of water temperature on plant morphology, biomass accumulation and oxygen-exchange for five clones of the submerged aquatic macrophyte Potamogeton

  17. Impact of invasive crayfish on water quality and aquatic macrophytes in the Netherlands

    NARCIS (Netherlands)

    Roessink, Ivo; Gylstra, Ronald; Heuts, Peter G.M.; Specken, Bart; Ottburg, Fabrice

    2017-01-01

    Several species of invasive crayfish have become established in the Netherlands, the most recent addition being Orconectes virilis. Since crayfish are known to impact water quality and aquatic macrophytes in areas they invade, this study investigated whether this was also the case for this

  18. Different response of phytochelatins in two aquatic macrophytes ...

    African Journals Online (AJOL)

    In this study, two submerged macrophytes Ceratophyllum demersum L. and Elodea canadensis Michx. were adopted to investigate the response of phytochelatins (PCs) and its relationship with cadmium (Cd) toxicity upon exposure to low concentrations of Cd (0.01 to 0.64 μM) usually present in low or moderately polluted ...

  19. MACROPHYTE BIOASSAY APPLICATIONS FOR MONITORING PESTICIDES IN THE AQUATIC ENVIRONMENT

    OpenAIRE

    VECHIA,J.F. DELLA; CRUZ, C; Silva, A. F.; CERVEIRAJR., W.R.; GARLICH,N.

    2016-01-01

    ABSTRACT The objective of this study was to evaluate the feasibility of the use of macrophytes Lemna minor and Azolla caroliniana as biomarkers of exposure (acute toxicity) for atrazine, bentazon + imazamox and clomazone, insecticide alpha cypermethrin + teflubenzuron and fungicides pyraclostrobin and mixture pyraclostrobin + epoxiconazole, as well as the risk for environmental intoxication. For this purpose, four plants of L. minor and five of A. caroliniana were selected in a 50 mL Hoagland...

  20. The role of herbivorous water birds in aquatic systems through interactions with aquatic macrophytes, with special reference to the Bewick's Swan - Fennel Pondweed system

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Nolet, B.A.

    2007-01-01

    The role of aquatic macrophytes in stimulating biodiversity and maintaining clear waters is currently undisputed. The management of (eutrophic) shallow waters is therefore often directed at (re-)establishing macrophyte domination. In contrast, the role of water birds has long been considered of

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

    Directory of Open Access Journals (Sweden)

    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

  2. Trace element accumulation and distribution in four aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Mazej, Z.; Germ, M. [ERICo Velenje Environmental Research and Industrial Cooperation Doo, Velenje (Slovenia)

    2009-02-15

    The concentration of trace elements was studied in different parts of the submersed species Najas marina and Potamogeton lucens and in floating-leaved species Nuphar lutea and Potamogeton nodosus, and also in the corresponding samples of water and sediment in the artificial lake Velenjsko jezero, where the large amount of ash from lignite coal (about 15 million tons) is deposited at the bottom. The concentration of trace elements in water was mainly below the detection limit. In sediment only the concentration of As was found to be above the average European background concentration. It also showed the highest degree of translocation from sediment into plant roots, but its mobility to above-ground plant parts was negligible. The submersed species N. marina and P. lucens exhibited similar concentrations of trace elements in their organs. Of the floating-leaved species, the lowest concentrations of trace elements were found in N. lutea and the largest in P. nodosus. Significantly higher concentrations of As, Ni, Pb and Cr were shown in roots of N. marina, P. lucens and P. nodosus than in their stems and leaves, whereas Cu and Zn were equally distributed throughout all their organs. Cr and Ni also showed relatively high mobility from roots to upper parts of N. lutea.

  3. 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

  4. Submersed aquatic vegetation in Chesapeake Bay: Sentinel species in a changing world

    Science.gov (United States)

    Orth, Robert J.; Dennison, William C.; Lefcheck, Jonathon S.; Gurbisz, Cassie; Hannam, Michael; Keisman, Jennifer; Landry, J. Brooke; Moore, Kenneth A.; Murphy, Rebecca R.; Patrick, Christopher J.; Testa, Jeremy; Weller, Donald E.; Wilcox, David J.

    2017-01-01

    Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society. In Chesapeake Bay, SAV species are also indicators of environmental change because of their sensitivity to water quality and shoreline development. As such, SAV has been deeply integrated into regional regulations and annual assessments of management outcomes, restoration efforts, the scientific literature, and popular media coverage. Even so, SAV in Chesapeake Bay faces many historical and emerging challenges. The future of Chesapeake Bay is indicated by and contingent on the success of SAV. Its persistence will require continued action, coupled with new practices, to promote a healthy and sustainable ecosystem.

  5. Aquatic macrophytes from Danube Delta lagoons Musura Bay and Zatonul Mare

    Directory of Open Access Journals (Sweden)

    Sava D.,

    2016-05-01

    Full Text Available The Romanian Danube Delta, a unique, young and continuing to grow region situated in the eastern part of Europe, is the largest continuous marshland and the second largest delta on the continent, and also a favorable place for developing a unique flora and fauna in Europe, with many rare and protected species. The predominance of the aquatic environment, led to the existence of a particular macrophytic flora. In this context, the purpose of this paper is to contribute to the study of aquatic macrophytes. The present study took place over two years, between 2013-2014, and in each year a number of expeditions were made in the two lagoons (Musura Bay and Zătonul Mare in different seasons, in order to observe the diverse flora, because, due to seasonal variation in water quality, there might be a significantly seasonality of the vegetation also.

  6. Arsenic uptake by aquatic macrophyte Spirodela polyrhiza L.: Interactions with phosphate and iron

    OpenAIRE

    Rahman, M.A.; Hasegawa, Hiroshi; Ueda, Kazumasa; Maki, Teruya; Rahman, M.M.

    2008-01-01

    The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L. was investigated to determine the influence of arsenic interaction with PO43- and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-ethylenediaminetetraacetic acid (CBE) technique. S. polyrhiza L. accumulated 51-fold arsenic from arsenat...

  7. An invasion risk map for non-native aquatic macrophytes of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Argantonio Rodríguez-Merino

    2017-05-01

    Full Text Available Freshwater systems are particularly susceptible to non-native organisms, owing to their high sensitivity to the impacts that are caused by these organisms. Species distribution models, which are based on both environmental and socio-economic variables, facilitate the identification of the most vulnerable areas for the spread of non-native species. We used MaxEnt to predict the potential distribution of 20 non-native aquatic macrophytes in the Iberian Peninsula. Some selected variables, such as the temperature seasonality and the precipitation in the driest quarter, highlight the importance of the climate on their distribution. Notably, the human influence in the territory appears as a key variable in the distribution of studied species. The model discriminated between favorable and unfavorable areas with high accuracy. We used the model to build an invasion risk map of aquatic macrophytes for the Iberian Peninsula that included results from 20 individual models. It showed that the most vulnerable areas are located near to the sea, the major rivers basins, and the high population density areas. These facts suggest the importance of the human impact on the colonization and distribution of non-native aquatic macrophytes in the Iberian Peninsula, and more precisely agricultural development during the Green Revolution at the end of the 70’s. Our work also emphasizes the utility of species distribution models for the prevention and management of biological invasions.

  8. 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

  9. 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.

  10. Algal communities associated with aquatic macrophytes in some ...

    African Journals Online (AJOL)

    Four distinct diatom communities were identified, using Canonical Correspondence Analysis. The constant dominant taxa were Achnanthes sp., Gomphonema gracile and Pinnularia gibba. The analysis showed that all samples from the same pond were grouped together, irrespective of the aquatic plants sampled.

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

    African Journals Online (AJOL)

    Three aquatic plants, coontail (Ceratophyllum demersum L.), hydrilla [Hydrilla verticillata (L. f.) Royle] and giant duckweed [Spirodela polyrhiza (L.) Schleiden], were successfully surface sterilized and cultured on liquid basal MS (Murashige and Skoog, 1962) medium under aseptic conditions. Shoot explants obtained from ...

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

    African Journals Online (AJOL)

    admin

    2013-09-25

    Sep 25, 2013 ... Three aquatic plants, coontail (Ceratophyllum demersum L.), hydrilla [Hydrilla verticillata (L. f.) Royle] and giant duckweed [Spirodela polyrhiza (L.) Schleiden], were successfully surface sterilized and cultured on liquid basal MS (Murashige and Skoog, 1962) medium under aseptic conditions. Shoot.

  13. 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.

  14. Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon

    Directory of Open Access Journals (Sweden)

    L Sciessere

    2011-09-01

    Full Text Available Due to the connection between enzymatic activity and degradation of different fractions of organic matter, enzyme assays can be used to estimate degradation rates of particulate and dissolved organic carbon in freshwater systems. The aim of this study was to quantify and model the enzymatic degradation involving the decomposition of macrophytes, describing temporal activity of cellulases (EC 3.2.1.4 and EC 3.2.1.91 and xylanase (EC 3.2.1.8 during in situ decomposition of three aquatic macrophytes (Salvinia sp., Eichhornia azurea and Cyperus giganteus on the surface and water-sediment interface (w-s interface of an oxbow lagoon (Óleo lagoon within a natural Brazilian Savanna Reserve. Overall, the enzymatic degradation of aquatic macrophytes in Óleo lagoon occurred during the whole year and was initiated together with leaching. Xylanase production was ca. 5 times higher than cellulase values due to easy access to this compound by cellulolytic microorganisms. Enzymatic production and detritus mass decay were similar on the surface and w-s interface. Salvinia sp. was the most recalcitrant detritus, with low mass decay and enzymatic activity. E. azurea and C. giganteus decomposition rates and enzymatic production were high and similar. Due to the physicochemical homogeneity observed in the Óleo lagoon, the differences between the decay rates of each species are mostly related with detritus chemical quality.

  15. MACROPHYTE RICHNESS AND AQUATIC VEGETATION COMPLEXITY OF THE LAKE IDRO (NORTHERN ITALY

    Directory of Open Access Journals (Sweden)

    R. Bolpagni

    2013-04-01

    Full Text Available A detailed survey was performed to examine the floristic richness and the structural complexity, spatial patterns and conservation value of aquatic plant communities within the littorals of Lake Idro (northern Italy. During the summers of 2010-2011 we proceeded to characterize aquatic macrophyte meadows applying standardized procedures using transects (44 and plots (49 arrayed perpendicular to the shoreline and randomly positioned within the vegetated belt, respectively. Lake Idro is characterized by rather high floristic richness (20 macrophytes but low levels of vegetation structural complexity (8 vegetation units. Nevertheless, a clear zonation of the littoral vegetation was identified with two main macro-layers: a deeper layer (between 6-10 m of depth dominated by Chara globularis and an upper one (from 6 m of depth to water-air atmosphere mainly colonized by alien elodeids (mainly Elodea nuttallii and Lagarosiphon major. For the first time a complete floristic-vegetation analysis of the Lake Idro was presented. Our data confirm the poor ecological status of the basin, even though the lacustrine vegetation can be considered of conservation concern. Further investigations are needed to improve present evaluations, especially with respect to the impact of eutrophication on macrophytic communities.

  16. Efficiency of the aquatic macrophyte salvinia auriculata in purification of urban effluents, validated by allium test (Allium Cepa L.

    Directory of Open Access Journals (Sweden)

    Priscila S. Gonçalves

    2015-12-01

    Full Text Available This study aimed to evaluate the efficiency of the aquatic macrophytes Salvinia auriculata Aublet in purification of polluted effluents, and evaluate macroscopically the efficiency of macrophytes using the Allium cepa Linnaeus (onion test. Three collections were performed in September 2011, the first analysis was performed with water collected directly from River Santa Catarina, the second was performed seven days after the contact of the effluent with the macrophytes, and the third, fifteen days after the first analyses. The data were analyzed using Student’s t-test (p<0.05. To verify the normality of the data was used the Kolmogorov-Smirnov test (p<0.05, for each sample (treatment. According to the results of the Allium test, the aquatic macrophyte S. auriculata was efficient in the removing of pollutants agents after fifteen days in contact with the effluent.

  17. A Simulation Model for Growth of the Submersed Aquatic Macrophyte Sago Pondweed (Potamogeton pectinatus L.)

    National Research Council Canada - National Science Library

    Best, Elly

    2003-01-01

    .... The characteristics of community and site can be easily modified by the user. POTAM incorporates insight into the processes affecting the dynamics of a sago pondweed community in relatively shallow, hard water (0.1-to 6-m depth...

  18. Sediment bioassay with sago pondweed (Potamogeton pectinatus), a submersed aquatic macrophyte

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, W.J. [NBS, Raleigh, NC (United States); Siesko, M.M. [North Carolina State Univ., Raleigh, NC (United States); Ailstock, M.S. [Anne Arundel Community College, Arnold, MD (United States)

    1994-12-31

    Sago pondweed explants produced in tissue culture were grown for 6 weeks in sediments from Baltimore Harbor, MD. Although sediments contained up to 9,800 ppm Al, 7.5 ppm Cd, 3,090 ppm Cr, 397 ppm Pb, 530 Cu, 1,320 Sn, 2,040 ppm Zn, and 82,900 ppm oil and grease (all expressed as dry wt.) stepwise linear regression of log transformed contaminant data showed no linkage of reduced plant growth to the contaminants measured. Plant growth was negatively correlated with particle size and particle size was negatively correlated with most contaminant concentrations. In a second study, 17 estuarine sediments, representing a range of low to very high toxicity in Microtox and Hyalella azteca bioassays, were selected for study. Selected sediments contained up to 10 ppm Cd, 135 ppm Cr, 21 ppm Cu, 105 ppm Pb, 15 ppm Ni, and 190 ppm Zn (all expressed as dry wt.). Sago pondweed explants were planted into these sediments and grown for 4 weeks. Biomass production differed significantly among sediments tested. Phytotoxicity of sediments did not correlate well with the toxicity results of the Microtox and Hyalella azteca bioassays nor the metal content of sediments.

  19. Combined effect of predatory zooplankton and allelopathic aquatic macrophytes on algal suppression.

    Science.gov (United States)

    Zuo, Shengpeng; Wan, Kun; Ma, Sumin

    2015-01-01

    The present study evaluated the combined effects of four typical predatory zooplankton and allelopathic aquatic macrophytes on algal control in a microcosm system. It would determine the effects of diverse species and biological restoration on the growth of harmful water-bloom microalgae in great lakes polluted by excess nutrients. It was found that the mixtures of each zooplankton and the floating plant Nymphoides peltatum had stronger inhibitory effects on harmful water-bloom microalgae than the individual species in clean or eutrophic water bodies. In addition, a community of four zooplankton types had a synergistic effect on algal inhibition. Algal suppression by the zooplankton community was enhanced significantly when the macrophyte was co-cultured in the microcosm. Furthermore, Chlorella pyrenoidosa was more susceptible than Microcystis aeruginosa when exposed to grazing by zooplankton and the allelopathic potential of the macrophyte. Algal inhibition was also weaker in eutrophic conditions compared with the control. These findings indicate that diverse species may enhance algal inhibition. Therefore, it is necessary to restore biological diversity and rebuild an ecologically balanced food chain or web to facilitate the control of harmful algal blooms in eutrophic lakes.

  20. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India.

    Science.gov (United States)

    Khatun, Amina; Pal, Sandipan; Mukherjee, Aloke Kumar; Samanta, Palas; Mondal, Subinoy; Kole, Debraj; Chandra, Priyanka; Ghosh, Apurba Ratan

    2016-01-01

    The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg)>Cu (29.9±10.2 mg/kg)>Pb (22.7±10.3 mg/kg)>Cd (3.7±2.2 mg/kg). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (pCu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p<0.05 level. Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta.

  1. Richness and distribution of aquatic macrophytes in a subtropical reservoir in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pavão

    2017-08-01

    Full Text Available Abstract Aims: to evaluate the richness, biomass and distribution of aquatic macrophytes in a subtropical reservoir in the dry and rainy seasons. Methods this study was carried out in the Itupararanga Reservoir, an important water source in São Paulo State, undergoing a continuous process of eutrophication. Samples of macrophytes were collected at 12 sampling sites in the summer and at 9 sampling sites in the winter in the Itupararanga Reservoir using the quadrat method (0.25 m2. In the laboratory, the plants were washed to remove the coarse material and then were dried (60 °C for biomass determination (gDW. m-2. All the species in the sampling sites in both periods were identified using the specific literature. In each sampling site, the water temperature, pH, electrical conductivity and dissolved oxygen were measured using a probe. The temporal and spatial differences were analyzed using t-test and a Cluster Analysis was performed. Results The checklist showed sixteen species, 75% of them were emergent. From the 16 species, 15 were present in the summer and 10 in the winter. Eichhornia crassipes, Polygonum sp., and Urochloa sp. were the frequent taxa and had the highest biomass in both periods. The winter showed the highest biomass mainly due to the growth of free-floating species. The headwaters of the reservoir, the most eutrophic region, showed that the highest macrophyte richness and the sampling sites of this area were clustered in both the summer and winter. Conclusions There was no significant spatial variation among the measured variables. E. crassipes, Salvinia sp. and Urochloa sp. showed a significant variation of biomass between two periods. Urochloa sp. is a nuisance species occurring in up to 60% of the sampling sites having implications for the whole catchment. Continuous macrophyte monitoring is important due to the increasing trophic status of this ecosystem.

  2. Aquatic Plant Control Research Program: The Habitat Value of Aquatic Macrophytes for Macroinvertebrates

    Science.gov (United States)

    1989-11-01

    26.1 percent) and cladocerans (25.5 percent). However, in dense vegetation, copepods comprised more than 50 percent of the sample, while rotifers...2u.z percent) anu cladocerans (21.8 percent) were subdominint. In the sparse vegetation, rotifers were more numerous than copepods. Maccoinvertebrate...40 PART VII: A REVIEW OF THE LITERATURE UN iht mABItAT VALUE OF AQUAIIC MACROPHYTES .................................... 43

  3. Hydrologic cycle and dynamics of aquatic macrophytes in two intermittent rivers of the semi-arid region of Brazil

    Directory of Open Access Journals (Sweden)

    F. Pedro

    Full Text Available The dynamics of aquatic macrophytes in intermittent rivers is generally related to the characteristics of the resistance and resilience of plants to hydrologic disturbances of flood and drought. In the semi-arid region of Brazil, intermittent rivers and streams are affected by disturbances with variable intensity, frequency, and duration throughout their hydrologic cycles. The aim of the present study is to determine the occurrence and variation of biomass of aquatic macrophyte species in two intermittent rivers of distinct hydrologic regimes. Their dynamics were determined with respect to resistance and resilience responses of macrophytes to flood and drought events by estimating the variation of biomass and productivity throughout two hydrologic cycles. Twenty-one visits were undertaken in the rewetting, drying, and drought phases in a permanent puddle in the Avelós stream and two temporary puddles in the Taperoá river, state of Paraíba, Northeast Brazil. The sampling was carried out by using the square method. Floods of different magnitudes occurred during the present study in the river and in the stream. The results showed that floods and droughts are determining factors in the occurrence of macrophytes and in the structure of their aquatic communities. The species richness of the aquatic macrophyte communities was lower in the puddles of the river and stream subject to flood events, when compared to areas where the run-off water is retained. At the beginning of the recolonization process, the intensity of the floods was decisive in the productivity and biomass of the aquatic macrophytes in the Taperoá river and the Avelós stream. In intermediate levels of disturbance, the largest values of productivity and biomass and the shortest time for starting the recolonization process occurred.

  4. Simulated bioavailability of phosphorus from aquatic macrophytes and phytoplankton by aqueous suspension and incubation with alkaline phosphatase.

    Science.gov (United States)

    Feng, Weiying; Wu, Fengchang; He, Zhongqi; Song, Fanhao; Zhu, Yuanrong; Giesy, John P; Wang, Ying; Qin, Ning; Zhang, Chen; Chen, Haiyan; Sun, Fuhong

    2018-03-01

    Bioavailability of phosphorus (P) in biomass of aquatic macrophytes and phytoplankton and its possible relationship with eutrophication were explored by evaluation of forms and quantities of P in aqueous extracts of dried macrophytes. Specifically, effects of hydrolysis of organically-bound P by the enzyme alkaline phosphatase were studied by use of solution 31P-nuclear magnetic resonance (NMR) spectroscopy. Laboratory suspensions and incubations with enzymes were used to simulate natural releases of P from plant debris. Three aquatic macrophytes and three phytoplankters were collected from Tai Lake, China, for use in this simulation study. The trend of hydrolysis of organic P (Po) by alkaline phosphatase was similar for aquatic macrophytes and phytoplankton. Most monoester P (15.3% of total dissolved P) and pyrophosphate (1.8%) and polyphosphate (0.4%) and DNA (3.2%) were transformed into orthophosphate (14.3%). The major forms of monoester P were glycerophosphate (8.8%), nucleotide (2.5%), phytate (0.4%) and other monoesters P (3.6%). Proportions of Po including condensed P hydrolyzed in phytoplankton and aquatic macrophytes were different, with the percentage of 22.6% and 6.0%, respectively. Proportion of Po hydrolyzed in debris from phytoplankton was approximately four times greater than that of Po from aquatic macrophytes, and could be approximately twenty-five times greater than that of Po in sediments. Thus, release and hydrolysis of Po, derived from phytoplankton debris would be an important and fast way to provide bioavailable P to support cyanobacterial blooming in eutrophic lakes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Decomposition characteristics of three different kinds of aquatic macrophytes and their potential application as carbon resource in constructed wetland.

    Science.gov (United States)

    Wu, Suqing; He, Shengbing; Zhou, Weili; Gu, Jianya; Huang, Jungchen; Gao, Lei; Zhang, Xu

    2017-12-01

    Decomposition of aquatic macrophytes usually generates significant influence on aquatic environment. Study on the aquatic macrophytes decomposition may help reusing the aquatic macrophytes litters, as well as controlling the water pollution caused by the decomposition process. This study verified that the decomposition processes of three different kinds of aquatic macrophytes (water hyacinth, hydrilla and cattail) could exert significant influences on water quality of the receiving water, including the change extent of pH, dissolved oxygen (DO), the contents of carbon, nitrogen and phosphorus, etc. The influence of decomposition on water quality and the concentrations of the released chemical materials both followed the order of water hyacinth > hydrilla > cattail. Greater influence was obtained with higher dosage of plant litter addition. The influence also varied with sediment addition. Moreover, nitrogen released from the decomposition of water hyacinth and hydrilla were mainly NH3-N and organic nitrogen while those from cattail litter included organic nitrogen and NO3(-)-N. After the decomposition, the average carbon to nitrogen ratio (C/N) in the receiving water was about 2.6 (water hyacinth), 5.3 (hydrilla) and 20.3 (cattail). Therefore, cattail litter might be a potential plant carbon source for denitrification in ecological system of a constructed wetland. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Use of aquatic macrophytes in substrate composition to produce moringa seedlings

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2016-03-01

    Full Text Available The use of aquatic macrophytes in substrate composition to produce seedlings of moringa is a sustainable alternative. Therefore, the objective of this research was to evaluate the development of moringa seedlings using substrates composed with aquatic macrophytes, and to determine concentrations of N, P and K in the seedlings. We used different combinations of weeds (M, manure (E and topsoil (TV to compose the substrates. The experiment was conducted in a 3 × 4 factorial in randomized arrangement with four replications. We evaluated plant height, crown diameter and stem, relative growth rate in height, canopy diameter and in stem, dry matter of aerial part and of roots, root length and root/shoot ratio, besides the content of N, P and K in seedlings. Moringa seedlings showed reduced growth when produced in substrates composed only with cattail. Water lettuce and substrates composed of 60% M + 30%E + 10 % TV and 70% M + 30% E, promoted greater nutrition and growth of moringa seedlings. The substrate 60M +30E +10TV composed by water hyacinth and cattail resulted in greater amount of P in moringa seedlings.

  7. Effect of chlorsulfuron on growth of submerged aquatic macrophyte Potamogeton pectinatus (sago pondweed).

    Science.gov (United States)

    Coyner, A; Gupta, G; Jones, T

    2001-01-01

    Research has been conducted on the effect of chlorsulfuron on non-target plants but little information is available on its effects on aquatic macrophytes. Potamogeton pectinatus (sago pondweed) is an ecologically important submerged aquatic macrophyte found in freshwater bodies. Many species of wildlife use this plant as a food source. The objective of this study was to measure the phytotoxic effects of chlorsulfuron on sago pondweed. P. pectinatus plants were exposed to chlorsulfuron at 0, 0.25, 0.50, 1.0, or 2.0 ppb, in an environmental growth chamber. Plants exposed to 0.25 ppb chlorsulfuron showed a reduction in length (76%), number of leaves (50%), and number of stems (50%), compared to control plants. A reduction (47%) was also observed in the length of stems produced by plants treated with > or = 0.50 ppb chlorsulfuron. Significant reductions in wet and dry weights, and increased mortality were observed on treatments with > or = 1.0 ppb chlorsulfuron.

  8. Variation of nutrient and metal concentrations in aquatic macrophytes along the Rio Cachoeira in Bahia (Brazil).

    Science.gov (United States)

    Klump, Andreas; Bauer, Konrad; Franz-Gerstein, Charis; de Menezes, Max

    2002-07-01

    The use of cuprous fungicides in cocoa production in the southern part of the state of Bahia (Brazil) for decades has caused an accumulation of copper in various components of the cocoa plantations, and a contamination of regional freshwater ecosystems is suspected. Urban and industrial sources are supposed to contribute to water pollution and eutrophication of the Rio Cachoeira, the main river in this region. In order to study the metal contamination and nutritional status of this freshwater ecosystem, samples of the aquatic macrophytes Eichhornia crassipes and Pistia stratiotes were collected at seven sites along the river course. The samples were analysed for their copper, aluminium, chromium, nitrogen and phosphorus concentrations. The levels of heavy metals increased in the downstream direction, particularly in the roots of water hyacinth. A dramatic increase of nitrogen and phosphorus concentrations in water as well as in plant tissues was found in samples collected downstream from the city of Itabuna. Metal input and eutrophication were attributed to agricultural, industrial and urban sources in the region. Biomonitoring of the water quality using aquatic macrophytes as accumulative indicator plants is recommended in addition to chemical water analyses.

  9. Effects of water turbulence on variations in cell ultrastructure and metabolism of amino acids in the submersed macrophyte, Elodea nuttallii (Planch.) H. St. John.

    Science.gov (United States)

    Atapaththu, K S S; Miyagi, A; Atsuzawa, K; Kaneko, Y; Kawai-Yamada, M; Asaeda, T

    2015-09-01

    The interactions between macrophytes and water movement are not yet fully understood, and the causes responsible for the metabolic and ultrastructural variations in plant cells as a consequence of turbulence are largely unknown. In the present study, growth, metabolism and ultrastructural changes were evaluated in the aquatic macrophyte Elodea nuttallii, after exposure to turbulence for 30 days. The turbulence was generated with a vertically oscillating horizontal grid. The turbulence reduced plant growth, plasmolysed leaf cells and strengthened cell walls, and plants exposed to turbulence accumulated starch granules in stem chloroplasts. The size of the starch granules increased with the magnitude of the turbulence. Using capillary electrophoresis-mass spectrometry (CE-MS), analysis of the metabolome found metabolite accumulation in response to the turbulence. Asparagine was the dominant amino acid that was concentrated in stressed plants, and organic acids such as citrate, ascorbate, oxalate and γ-amino butyric acid (GABA) also accumulated in response to turbulence. These results indicate that turbulence caused severe stress that affected plant growth, cell ultrastructure and some metabolic functions of E. nuttallii. Our findings offer insights to explain the effects of water movement on the functions of aquatic plants. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

    Science.gov (United States)

    Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

  11. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India

    Directory of Open Access Journals (Sweden)

    Amina Khatun

    2016-09-01

    Full Text Available Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd, copper (Cu, manganese (Mn, and lead (Pb were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg>Cu (29.9±10.2 mg/kg>Pb (22.7±10.3 mg/kg>Cd (3.7±2.2 mg/kg. The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p<0.001 between soil organic carbon (OC percentage and Mn (r =0.771, and sediment OC percentage and Pb (r=0.832. Cation exchange capacity (CEC also showed a positive correlation (p<0.001 with Cu (r=0.721, Mn (r=0.713, and Pb (r=0.788, while correlations between sediment OC percentage and Cu (r=0.628, sediment OC percentage and Cd (r=0.559, and CEC and Cd (r=0.625 were significant at the p<0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta.

  12. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India

    Science.gov (United States)

    2016-01-01

    Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg)>Cu (29.9±10.2 mg/kg)>Pb (22.7±10.3 mg/kg)>Cd (3.7±2.2 mg/kg). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p<0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation (p<0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p<0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta. PMID:27669754

  13. 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.

  14. Toxicity, accumulation, and removal of heavy metals by three aquatic macrophytes.

    Science.gov (United States)

    Basile, A; Sorbo, S; Conte, B; Cobianchi, R Castaldo; Trinchella, F; Capasso, C; Carginale, V

    2012-04-01

    A comprehensive understanding of the uptake, tolerance, and transport of heavy metals by plants will be essential for the development of phytoremediation technologies. In the present paper, we investigated accumulation, tissue and intracellular localization, and toxic effects of cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) in three aquatic macrophytes (the angiosperms Lemna minor and Elodea canadensis, and the moss Leptodictyum riparium). We also tested and compared their capacity to absorb heavy metal from water under laboratory conditions. Our data showed that all the three species examined could be considered good bioaccumulators for the heavy metals tested. L. riparium was the most resistant species and the most effective in accumulating Cu, Zn, and Pb, whereas L. minor was the most effective in accumulating Cd. Cd was the most toxic metal, followed by Pb, Cu, and Zn. At the ultrastructural level, sublethal concentrations of the heavy metals tested caused induced cell plasmolysis and alterations of the chloroplast arrangement. Heavy metal removal experiments revealed that the three macrophytes showed excellent performance in removing the selected metals from the solutions in which they are maintained, thus suggesting that they could be considered good candidates for wastewaters remediation purpose.

  15. [Aquatic macrophytes from a marginal lake of the Embu-mirim river, São Paulo, Brazil].

    Science.gov (United States)

    Beyruth, Z

    1992-08-01

    In the years 1984/1985, limnological surveys were carried out at a marginal pond of the Embu-mirim river belonging to the hydrographic basin of Guarapiranga Reservoir (S. Paulo, Brazil), in order to obtain data for the determination of physical, chemical and biological parameters. Results obtained from the study of the aquatic macrophytes and their relationships with other environmental parameters are analyzed. Eichhornia crassipes (Mart.) Solms, the dominant macrophyte, was observed in several water bodies of that basin, including the river it self, thus favoring an evaluation of its behavior in similar water bodies of the basin.

  16. Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae

    Directory of Open Access Journals (Sweden)

    F. Freitas

    2017-07-01

    Full Text Available Abstract Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu accumulation by Salvinia biloba Raddi (Salviniaceae in different metal concentrations (1, 3 and 5 µg mL-1, as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days. The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

  17. Water quality and avian inputs as sources of isotopic variability in aquatic macrophytes and macroinvertebrates

    Directory of Open Access Journals (Sweden)

    Esther Sebastian-Gonzalez

    2012-01-01

    Full Text Available Different factors can affect the isotopic values of aquatic organisms. Nevertheless, water quality may be very important for aquatic organisms because they directly depend on it. In this article, we aimed to investigate if variations in the chemical and biological water characteristics affect the stable isotope values of aquatic organisms. We also wished to discuss alternative sources of isotopic variability. We analysed the water chemical characteristics, the input of extra nitrates from bird guano, and the δ15N and δ13C values for the macroinvertebrates and macrophytes present in freshwater irrigation ponds. Variability in the values of the analysed stable isotopes was high, even for the same species in different ponds. Water conductivity, nitrates, ammonium, organic nitrogen concentrations and COD (Chemical Oxygen Demand directly correlated with the isotopic values. Besides, the input of extra nitrates from Larids’ (gulls and terns guano might also increase the δ15N values at the ponds which these birds most intensively use. Nevertheless, the high δ15N values are difficult to explain in terms of water characteristics and excrements inputs and only general processes of denitrification could explain these values. Longer water residence times could cause extremely enriched isotopic values in both DIC (Dissolved Inorganic Carbon and dissolved nitrates. This study shows different sources of isotopic variability which can prove useful to interpret stable isotopes studies.

  18. Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae).

    Science.gov (United States)

    Freitas, F; Lunardi, S; Souza, L B; von der Osten, J S C; Arruda, R; Andrade, R L T; Battirola, L D

    2017-07-10

    Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu) accumulation by Salvinia biloba Raddi (Salviniaceae) in different metal concentrations (1, 3 and 5 µg mL-1), as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days). The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

  19. 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.

  20. Response of sago pondweed, a submerged aquatic macrophyte, to herbicides in three laboratory culture systems

    Science.gov (United States)

    Fleming, W.J.; Ailstock, M.S.; Momot, J.J.; Norman, C.M.; Gorsuch, Joseph W.; Lower, William R.; Wang, Wun-cheng; Lewis, M.A.

    1991-01-01

    The phytotoxicity of atrazine, paraquat, glyphosate, and alachlor to sago pondweed (Potamogeton pectinatus), a submerged aquatic macrophyte, was tested under three types of laboratory culture conditions. In each case, tests were conducted in static systems, the test period was four weeks, and herbicide exposure was chronic, resulting from a single addition of herbicide to the test vessels at the beginning of the test period. The three sets of test conditions employed were(1) axenic cultures in 125-mL flasks containing a nutrient media and sucrose; (2) a microcosm system employing 18.9-L buckets containing a sand, shell, and peat substrate; and (3) an algae-free system employing O.95-L jars containing reconstituted freshwater and a nutrient agar substrate. The primary variable measured was biomass production. Plants grew well in all three test systems, with biomass of untreated plants increasing by a factor of about 5 to 6.5 during the four-week test period. Biomass production in response to herbicide exposure differed significantly among culture systems, which demonstrates the need for a standardized testing protocol for evaluating the effects of toxics on submerged aquatic plants.

  1. Remediation of nitrite contamination in ground and surface waters using aquatic macrophytes.

    Science.gov (United States)

    Rawat, S K; Singh, R K; Singh, Rana P

    2012-01-01

    The study was carried out to determine the seasonal variation of nitrite levels in drinking and surface waters of urban, peri-urban and rural areas of Lucknow, during 2007-2008, and to evaluate the nitrite removal and accumulation potential of certain native aquatic macrophytes. Most of the drinking and surface water samples were collected from urbanized region of the city. All drinking water samples detected, showed higher nitrite level in winter, when compared with that in summer and rainy seasons. However, in drinking water samples nitrite level was below the permissible limit i.e. 3.29 mg l(-1) NO2. The surface water showed more than 3 fold higher levels of nitrite over the permissible level i.e. 0.06 mg l(-1), and the level was higher during rainy season than in summer and winterseasons. Eight macrophytes viz. Peltandra virginica, Utricularia vulgaris, Eichhomia crassipes, Trapa natans, Mimulus glabratus, Marsilea quadrifolia, Pistia stratiotes and Polygonum persicaria were studied for phytoremediation potential of nitrite from the water under simulated laboratory conditions. The gradual diminution in the level of nitrite in the water and simultaneously it's increase in the plant tissues was recorded at 5th, 10th and 15th d after plant culture. All the plants selected, removed nitrite from water but Polygonum persicaria, Mimulus glabratus, Trapa natans and Pistia stratiotes were found more efficient and removed nitrite upto 60.91, 58.09, 60.97 and 72.28%, respectively. Observations revealed that Pistia stratiotes can be used forthe effective removal of nitrite from the contaminated water.

  2. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    Science.gov (United States)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-01-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg−1 and 2318 to 8395 mg kg−1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p eutrophic lakes. PMID:27849040

  3. Aquatic macrophytes in the large, sub-tropical Itaipu Reservoir, Brazil

    Directory of Open Access Journals (Sweden)

    Roger Paulo Mormul

    2010-12-01

    Full Text Available In the last three decades, rapid assessment surveys have become an important approach for measuring aquatic ecosystem biodiversity. These methods can be used to detect anthropogenic impacts and recognize local or global species extinctions. We present a floristic survey of the aquatic macrophytes along the Brazilian margin of the Itaipu Reservoir conducted in 2008 and compare this with a floristic survey conducted ten years earlier. We used ordination analysis to determine whether assemblage composition differed among reservoir arms. Macrophyte species were sampled in each of the 235 sampling stations using a boat, which was positioned inside three places of each macrophyte stand to record species and search for small plants. We also collected submerged plants using a rake with the boat moving at constant velocity for ten minutes. We assigned individual macrophyte species to life form and identified representative species for each life form. A total of 87 macrophyte taxa were identified. The "emergent" life forms contained the highest number of species, followed by "rooted submerged" life forms. The extensive survey of macrophytes undertaken in September 2008 recorded more species than a survey conducted between 1995 and 1998. This could be due to changes in water physico-chemistry, disturbances due to water drawdown and the long period between surveys, which may have allowed natural colonization by other species. Additionally, differences in the classification systems and taxonomic resolution used in the surveys may account for differences in the number of species recorded. Assemblage composition varied among the arms and was affected by underwater radiation (as measured using a Secchi disk and fetch. Five non-native species were found. Two of these non-native species (Urochloa subquadripara and Hydrilla verticillata are of special concern because they have a high frequency of occurrence and occupy large marginal areas of the reservoir. Future

  4. Heavy metal pollution induced due to coal mining effluent on surrounding aquatic ecosystem and its management through naturally occurring aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, V.K.; Upadhyaya, A.R.; Pandey, S.K.; Tripathi, B.D. [Banaras Hindu University, Varanasi (India)

    2008-03-15

    Three aquatic plants Eichhornia crassipes, Lemna minor and Spirodela polyrhhiza were used in laboratory for the removal of heavy metals from the coal mining effluent. Plants were grown singly as well as in combination during 21 days phytoremediation experiment. Results revealed that combination of E. crassipes and L. minor was the most efficient for the removal of heavy metals while E. crassipes was the most efficient in monoculture. Significant correlations between metal concentration in final water and macrophytes were obtained. Translocation factor i.e. ratio of shoot to root metal concentration revealed that metals were largely retained in the roots of aquatic macrophytes. Analytical results showed that plant roots have accumulated heavy metals approximately 10 times of its initial concentration. These plants were also subjected to toxicity assessment and no symptom of metal toxicity was found therefore, this method can be applied on the large scale treatment of waste water where volumes generated are very high and concentrations of pollutants are low.

  5. Predictors of occurrence of the aquatic macrophyte Podostemum ceratophyllum in a southern Appalachian River

    Science.gov (United States)

    Argentina, Jane E.; Freeman, Mary C.; Freeman, Byron J.

    2010-01-01

    The aquatic macrophyte Podostemum ceratophyllum (Hornleaf Riverweed) commonly provides habitat for invertebrates and fishes in flowing-water portions of Piedmont and Appalachian streams in the eastern US. We quantified variation in percent cover by P. ceratophyllum in a 39-km reach of the Conasauga River, TN and GA, to test the hypothesis that cover decreased with increasing non-forest land use. We estimated percent P. ceratophyllum cover in quadrats (0.09 m2) placed at random coordinates within 20 randomly selected shoals. We then used hierarchical logistic regression, in an information-theoretic framework, to evaluate relative support for models incorporating alternative combinations of microhabitat and shoal-level variables to predict the occurrence of high (≥50%)P. ceratophyllum cover. As expected, bed sediment size and measures of light availability (location in the center of the channel, canopy cover) were included in best-supported models and had similar estimated-effect sizes across models. Podostemum ceratophyllum cover declined with increasing watershed size (included in 8 of 13 models in the confidence set of models); however, this decrease in cover was not well predicted by variation in land use. Focused monitoring of temporal and spatial trends in status of P. ceratophyllum are important due to its biotic importance in fast-flowing waters and its potential sensitivity to landscape-level changes, such as declines in forested land cover and homogenization of benthic habitats.

  6. Assessment of metal sorption mechanisms by aquatic macrophytes using PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Módenes, A.N., E-mail: anmodenes@yahoo.com.br [Department of Chemical Engineering-Postgraduate Program, West Parana State University, Campus of Toledo, rua da Faculdade 645, Jd. La Salle, 85903-000 Toledo, PR (Brazil); Espinoza-Quiñones, F.R.; Santos, G.H.F.; Borba, C.E. [Department of Chemical Engineering-Postgraduate Program, West Parana State University, Campus of Toledo, rua da Faculdade 645, Jd. La Salle, 85903-000 Toledo, PR (Brazil); Rizzutto, M.A. [Physics Institute, University of São Paulo, Rua do Matão s/n, Travessa R 187, 05508-900 São Paulo, SP (Brazil)

    2013-10-15

    Highlights: • Divalent metal ion removals by Egeria densa biosorbent. • Multielements concentrations in biosorbent samples by PIXE analysis. • Elements mass balance in liquid and solid phase before and after metal removals. • Assessment of the mechanisms involved in Cd{sup 2+} and Zn{sup 2+} removal by biosorbent. • Confirmation of the signature of ion exchange process in metal removal. -- Abstract: In this work, a study of the metal sorption mechanism by dead biomass has been performed. All batch metal biosorption experiments were performed using the aquatic macrophyte Egeria densa as biosorbent. Divalent cadmium and zinc solutions were used to assess the sorption mechanisms involved. Using a suitable equilibrium time of 2 h and a mixture of 300 mg biosorbent and 50 mL metal solution at pH 5, monocomponent sorption experiments were performed. In order to determine the residual amounts of metals in the aqueous solutions and the concentrations of removed metals in the dry biomass, Particle Induced X-ray Emission (PIXE) measurements in thin and thick target samples were carried out. Based on the strong experimental evidence from the mass balance among the major elements participating in the sorption processes, an ion exchange process was identified as the mechanism responsible for metal removal by the dry biomass.

  7. Photosynthetic performance of the aquatic macrophyte Althenia orientalis to solar radiation along its vertical stems.

    Science.gov (United States)

    Conde-Álvarez, Rafael M; Bañares-España, Elena; Nieto-Caldera, José Ma; Flores-Moya, Antonio; Figueroa, Félix L

    2011-08-01

    We have studied the plasticity of the photosynthetic apparatus in the endangered aquatic macrophyte Althenia orientalis to the gradient of light availability within its meadow canopy. We determined diurnal change in situ irradiance, light quality, in vivo chlorophyll a fluorescence, ex situ oxygen evolution rates, respiration rate and pigment concentration. The levels of photosynthetic photon flux density (PFD) and ultraviolet radiation (UVR) and the red/far-red ratio decreased with depth within the canopies of A. orientalis. Apical leaves had a greater decrease of the maximal quantum yield (F(v)/F(m)) in the morning and a faster recovery rate in the afternoon than those in the basal ones. The relative electron transport rate (ETRr) was not saturated at any time of the day, even in the apical leaves that received the highest light. The maximum light-saturated rate of gross photosynthesis (GP(max)) took place in apical leaves around noon. The chlorophyll a/b ratio values were higher, and the chlorophyll/carotenoid ratio values lower, in apical leaves than basal ones. The highest concentrations in total carotenoids were reached in the apical leaves around noon. A. orientalis has a high capacity to acclimatize to the changes in the light environment, both in quality and quantity, presenting sun and shade leaves in the same stem through the vertical gradient in the canopy.

  8. Thiols as biomarkers of heavy metal tolerance in the aquatic macrophytes of Middle Urals, Russia.

    Science.gov (United States)

    Borisova, Galina; Chukina, Nadezda; Maleva, Maria; Kumar, Adarsh; Prasad, M N V

    2016-10-02

    Aquatic macrophytes, viz. Sagittaria sagittifolia L., Lemna gibba L., Elodea canadensis Michx., Batrachium trichophyllum (Chaix.) Bosch., Ceratophyllum demersum L. and Potamogeton sp. (P. perfoliatus L., P. alpinus Balb., P. crispus L., P. berchtoldii Fieber, P. friesii Rupr., P. pectinatus L.) were collected from 11 sites for determining their metal accumulation and thiols content. Cu(2+), Ni(2+), Mn(2+), Zn(2+), and Fe(3+) exceeded maximum permissible concentrations in chosen sites. Significant transfer of metals from water to leaves is observed in the order of Ni(2+) < Cu(2+) < Zn(2+) < Fe(3+) < Mn(2+). The maximum variation of bioconcentration factor was noticed for manganese. The accumulation of heavy metals in leaves was correlated with non-protein and protein thiols, confirming their important role in metal tolerance. The largest contribution was provided by Cu(2+) (on the average r = 0.88, p < 0.05), which obviously can be explained as an important role of these ions in thiols synthesis. Increased synthesis of thiols in the leaves allows the usage of SH-containing compounds as biomarkers of metal tolerance. Considering accumulation of metals and tolerance, B. trichophyllum, C. demersum and L. gibba are the most suitable species for phytoremediation of highly multimetal contamination, while E. canadensis and some species of Potamageton are suitable for moderately metal-polluted sites.

  9. Arsenic uptake by aquatic macrophyte Spirodela polyrhiza L.: interactions with phosphate and iron.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H; Ueda, K; Maki, T; Rahman, M Mahfuzur

    2008-12-30

    The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L. was investigated to determine the influence of arsenic interaction with PO4(3-) and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-ethylenediaminetetraacetic acid (CBE) technique. S. polyrhiza L. accumulated 51-fold arsenic from arsenate solution compared to that from DMAA solution with initial concentrations of 4.0 and 0.02microM of arsenic and phosphate, respectively. The arsenate uptake was negatively (p0.05) with iron accumulation. The results suggest that adsorption of arsenate on Fe-plaque of the surface of S. polyrhiza L. contributes to the arsenic uptake significantly. Thus, arsenate uptake in S. polyrhiza L. occurred through the phosphate uptake pathway and by physico-chemical adsorption on Fe-plaques of plant surfaces as well. The S. polyrhiza L. uses different mechanisms for DMAA uptake.

  10. The capacity of aquatic macrophytes for phytoremediation and their disposal with specific reference to water hyacinth.

    Science.gov (United States)

    Newete, Solomon W; Byrne, Marcus J

    2016-06-01

    The actual amount of fresh water readily accessible for use is water on earth, and is expected to shrink further due to the projected growth of the population by a third in 2050. Worse yet are the major issues of water pollution, including mining and industrial waste which account for the bulk of contamination sources. The use of aquatic macrophytes as a cost-effective and eco-friendly tool for phytoremediation is well documented. However, little is known about the fate of those plants after phytoremediation. This paper reviews the options for safe disposal of waste plant biomass after phytoremediation. Among the few mentioned in the literature are briquetting, incineration and biogasification. The economic viability of such processes and the safety of their economic products for domestic use are however, not yet established. Over half of the nations in the world are involved in mining of precious metals, and tailings dams are the widespread legacy of such activities. Thus, the disposal of polluted plant biomass onto mine storage facilities such as tailing dams could be an interim solution. There, the material can act as mulch for the establishment of stabilizing vegetation and suppress dust. Plant decomposition might liberate its contaminants, but in a site where containment is a priority.

  11. Response of aquatic macrophytes to human land use perturbations in the watersheds of Wisconsin lakes, U.S.A.

    Science.gov (United States)

    Sass, Laura L.; Bozek, Michael A.; Hauxwell, Jennifer A.; Wagner, Kelly; Knight, Susan

    2010-01-01

    Aquatic macrophyte communities were assessed in 53 lakes in Wisconsin, U.S.A. along environmental and land use development gradients to determine effects human land use perturbations have on aquatic macrophytes at the watershed and riparian development scales. Species richness and relative frequency were surveyed in lakes from two ecoregions: the Northern Lakes and Forests Ecoregion and the Southeastern Wisconsin Till Plain Ecoregion. Lakes were selected along a gradient of watershed development ranging from undeveloped (i.e., forested), to agricultural to urban development. Land uses occurring in the watershed and in perimeters of different width (0–100, 0–200, 0–500, and 0–1000 m from shore, in the watershed) were used to assess effects on macrophyte communities. Snorkel and SCUBA were used to survey aquatic macrophyte species in 18 quadrats of 0.25 m2 along 14 transects placed perpendicular to shore in each lake. Effects of watershed development (e.g., agriculture and/or urban) were tested at whole-lake (entire littoral zone) and near-shore (within 7 m of shore) scales using canonical correspondence analysis (CCA) and linear regression. Overall, species richness was negatively related to watershed development, while frequencies of individual species and groups differed in level of response to different land use perturbations. Effects of land use in the perimeters on macrophytes, with a few exceptions, did not provide higher correlations compared to land use at the watershed scale. In lakes with higher total watershed development levels, introduced species, particularly Myriophyllumspicatum, increased in abundance and native species, especially potamids, isoetids, and floating-leaved plants, declined in abundance. Correlations within the northern and southeastern ecoregions separately were not significant. Multivariate analyses suggested species composition is driven by environmental responses as well as human development pressures. Both water

  12. Aquatic Macrophyte Approach to Assess the Impact of Disturbances on the Diversity of the Ecosystem and on River Quality

    Science.gov (United States)

    Thiébaut, Gabrielle

    2006-10-01

    Disturbance has long been recognized as an important determinant of community characteristics in aquatic systems. The aims of our study were to evaluate the impact of different disturbances on the macrophyte diversity and on river quality. To this end, we investigated the floristic composition for different stretches impacted by disturbances and we tested both diversity indices and the trophic index (IBMR) Biological Index Macrophytes in Rivers in the Moselle river (NE of France). The river was divided into four sections of different lengths based on uniformity of morphological characteristics, substrate conditions and flowing velocity: the upper, the wild, the resectioned and the downstream Moselle. Floristic composition and water chemical parameters were analysed from 1999 to 2001. The man-made increase of nutrient concentration favoured the floristic richness in the last sites of the upper Moselle, whereas river dynamics and floods did not allow the development of vegetation in the wild Moselle. Disturbances caused by industrial sewage and eutrophication allowed the spreading of pollu-tolerant and riparian alien species. The aquatic macrophyte approach is a useful means to detect impact of disturbances on diversity and on river quality. However, it was not effective in assessing disturbances such as flood overflow or chemical pollution.

  13. Accumulation of trace metals by aquatic macrophytes and their possible use in phytoremediation techniques

    Directory of Open Access Journals (Sweden)

    Michaela Hillermannová

    2008-01-01

    Full Text Available The aim of the performed research was to obtain knowledge on the ability of aquatic plants naturally growing at a site to absorb trace metals contained in bottom sediments and surface water. Furthermore, we compared differences in the accumulation of trace metals by the individual groups of aquatic plants (submerged and emergent and assessed a possible use of the individual plant species in phytoremediation techniques. Representative samples of water, sediments and aquatic macrophytes were taken from three anthropogenically loaded streams in six monitoring cycles in several collection profiles differing in the distance from a source of contamination. The samples were analysed for the total content of selected trace metals (As, Cd, Pb, Al, Hg, Zn, Fe, Mn, Cr, Ni and Cu. For comparison, one profile at an unloaded site was sampled as well. The obtained results were subjected to multivariate statistical analysis of data. Increased contents of Fe, Al, Mn, Cr and Zn were detected in sediments and plant biomass at loaded sites, namely 2–3× higher than at the comparing site. The contents of metals in surface water samples were altogether below the detection limit of the analytical method. When evaluating the individual plant species, we can state that the lowest contents of metals were detected in shore species (reed canary grass Phalaroides arundinacea, wood club-rush Scirpus silvaticus and red dock Rumex aquaticus; plant species growing in the very water current (water star-wort Callitriche sp. and flote-grass Glyceria fluitans exhibited mean contents of metals. In species forming mats (Fontinalis antipyretica and Cladophora sp., these contents were several times higher as compared to the previous species. The results of the performed research show that one of important factors, which influence the accumulation of trace metals in plants, is their ecological group (emergent – submerged affiliation and the species classification within this group

  14. Effects of temperature on decomposition of a potential nuisance species: the submerged aquatic macrophyte Egeria najas planchom (Hydrocharitaceae

    Directory of Open Access Journals (Sweden)

    P Carvalho

    Full Text Available Decomposition of aquatic plants is influenced by several biotic and abiotic factors. Among them, temperature plays an important role. Despite the increasing number of studies describing the effects of temperature on the decomposition of aquatic macrophytes, little attention has been given to the decay of submerged macrophytes. In this paper, we assessed the effect of temperature on weight loss and chemical composition of detritus of the submerged aquatic macrophyte Egeria najas Planchon (Hydrocharitaceae. Fresh plant material was maintained at 17ºC and 27ºC, in the dark, in incubation chambers. The overall decay process was best described by a linear model, with rates of 0.014 day-1 (R² = 94% and 0.045 day-1 (R² = 96% obtained at 17ºC and 27ºC, respectively. The analysis of covariance (ANCOVA indicated a significant difference between the decomposition rates at the two temperatures. The rapid breakdown of E. najas detritus, indicated by the decay coefficient, may be explained by its low content of resistant compounds such as cellulose and lignin. The variables analyzed in this study (pH, electrical conductivity, dissolved oxygen in the water and organic matter, total nitrogen and total phosphorus concentration in detritus showed accentuated responses at 27ºC. It is likely that the higher temperature increased microbial activity and, therefore, oxygen consumption in the water, consequently affecting the pH and the rate of ion and nutrient liberation into the aquatic ecosystem. Due to the rapid decomposition of E. najas at high temperatures, a small exportation is expected of this species from its stands to distant regions in tropical reservoirs, where it is considered a potential nuisance species.

  15. Biophysical interactions in fluvial ecosystems: effects of submerged aquatic macrophytes on hydro-morphological processes and ecosystem functioning

    Science.gov (United States)

    Cornacchia, Loreta; Davies, Grieg; Grabowski, Robert; van der Wal, Daphne; van de Koppel, Johan; Wharton, Geraldene; Bouma, Tjeerd

    2016-04-01

    Strong mutual interactions occur at the interface between biota and physical processes in biogeomorphic ecosystems, possibly resulting in self-organized spatial patterns. While these interactions and feedbacks have been increasingly studied in a wide range of landscapes previously, they are still poorly understood in lower energy fluvial systems. Consequently, their impact on the functioning of aquatic ecosystems is largely unknown. In this study we investigate the role of aquatic macrophytes as biological engineers of flow and sediment in lowland streams dominated by water crowfoot (Ranunculus spp.). Using field measurements from two annual growth cycles, we demonstrate that seasonally-changing macrophyte cover maintains relative constant flow rates, both within and between vegetation, despite temporal changes in channel flow discharge. By means of a mathematical model representing the interaction between hydrodynamics and vegetation dynamics, we reveal that scale-dependent feedbacks between plant growth and flow redistribution explain the influence of macrophytes on stabilizing flow rates. Our analysis reveals important implications for ecosystem functions. The creation of fast-flowing channels allows an adequate conveyance of water throughout the annual cycle; yet, patches also have a significant influence on sediment dynamics leading to heterogeneous habitats, thereby facilitating other species. As a last step we investigate the consequences on stream ecosystem functioning, by exploring the relationship between changes in macrophyte cover and the provision of different ecosystem functions (e.g. water conveyance, sediment trapping). Our results highlight that self-organization promotes the combination of multiple ecosystem functions through its effects on hydrological and morphological processes within biogeomorphic ecosystems.

  16. Responses of aquatic macrophyte cover and productivity to flooding variability on the Amazon floodplain.

    Science.gov (United States)

    Silva, Thiago S F; Melack, John M; Novo, Evlyn M L M

    2013-11-01

    Macrophyte net primary productivity (NPP) is a significant but understudied component of the carbon budget in large Amazonian floodplains. Annual NPP is determined by the interaction between stem elongation (vertical growth) and plant cover changes (horizontal expansion), each affected differently by flood duration and amplitude. Therefore, hydrological changes as predicted for the Amazon basin could result in significant changes in annual macrophyte NPP. This study investigates the responses of macrophyte horizontal expansion and vertical growth to flooding variability, and its possible effects on the contribution of macrophytes to the carbon budget of Amazonian floodplains. Monthly macrophyte cover was estimated using satellite imagery for the 2003-2004 and 2004-2005 hydrological years, and biomass was measured in situ between 2003 and 2004. Regression models between macrophyte variables and river-stage data were used to build a semiempirical model of macrophyte NPP as a function of water level. Historical river-stage records (1970-2011) were used to simulate variations in NPP, as a function of annual flooding. Vertical growth varied by a factor of ca. 2 over the simulated years, whereas minimum and maximum annual cover varied by ca. 3.5 and 1.5, respectively. Results suggest that these processes act in opposite directions to determine macrophyte NPP, with larger sensitivity to changes in vertical growth, and thus maximum flooding levels. Years with uncommonly large flooding amplitude resulted in the highest NPP values, as both horizontal expansion and vertical growth were enhanced under these conditions. Over the simulated period, annual NPP varied by ca. 1.5 (1.06-1.63 TgC yr(-1) ). A small increasing trend in flooding amplitude, and by extension NPP, was observed for the studied period. Variability in growth rates caused by local biotic and abiotic factors, and the lack of knowledge on macrophyte physiological responses to extreme hydrological conditions

  17. Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    to expansion of the area colonised by submerged macrophytes. Thus, the size of the colonised area is a better predictor of species richness than lake surface area. The strong increase in species richness accompanying greater transparency can be accounted for by the combined effect of higher colonised area...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

  18. Uranium accumulation in aquatic macrophytes in an uraniferous region: Relevance to natural attenuation.

    Science.gov (United States)

    Cordeiro, Cristina; Favas, Paulo J C; Pratas, João; Sarkar, Santosh Kumar; Venkatachalam, Perumal

    2016-08-01

    Phytoremediation potential of uranium (U) was investigated by submerged, free-floating and rooted emergent native aquatic macrophytes inhabiting along the streams of Horta da Vilariça, a uraniferous geochemical region of NE Portugal. The work has been undertaken with the following objectives: (i) to relate the U concentrations in water-sediment-plant system; and (ii) to identify the potentialities of aquatic plants to remediate U-contaminated waters based on accumulation pattern. A total of 25 plant species culminating 233 samples was collected from 15 study points along with surface water and contiguous sediments. Concentrations of U showed wide range of variations both in waters (0.61-5.56 μg L(-1), mean value 1.98 μg L(-1)) and sediments (124-23,910 μg kg(-1), mean value 3929 μg kg(-1)) and this is also reflected in plant species examined. The plant species exhibited the ability to accumulate U several orders of magnitude higher than the surrounding water. Maximum U concentrations was recorded in the bryophyte Scorpiurium deflexifolium (49,639 μg kg(-1)) followed by Fontinalis antipyretica (35,771 μg kg(-1)), shoots of Rorippa sylvestris (33,837 μg kg(-1)), roots of Oenanthe crocata (17,807 μg kg(-1)) as well as in Nasturtium officinale (10,995 μg kg(-1)). Scorpiurium deflexifolium displayed a high bioconcentration factor (BF) of ∼2.5 × 10(4) (mean value). The species Fontinalis antipyretica, Nasturtium officinale (roots) and Rorippa sylvestris (shoots) exhibited the mean BFs of 1.7 × 10(4), 5 × 10(3) and 4.8 × 10(3) respectively. Maximum translocation factor (TF) was very much pronounced in the rooted perennial herb Rorippa sylvestris showing extreme ability to transport U for the shoots and seems to be promising candidate to be used as bioindicator species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. The recovery and dynamics of submerged aquatic macrophyte vegeta­tion in the Wilderness lakes, southern Cape

    Directory of Open Access Journals (Sweden)

    P. J. Weisser

    1992-12-01

    Full Text Available Between 1979 and 1981, the submerged aquatic macrophyte vegetation in the Wilderness lakes died back significantly, and in some areas disappeared altogether. This study documents the senescent phase and describes the recovery of the plant populations between May 1982 and May 1983. In two lakes, namely Langvlei and Eilandvlei, the plant biomass approximately doubled between the winters of 1982 and 1983. Seasonal changes in species composition are documented and possible factors accounting for the collapse and recovery of the plant populations are discussed.

  20. Classification of submersed aquatic vegetation of the Venice lagoon using MIVIS airborne data

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    S. Pignatti

    2006-06-01

    Full Text Available In July 2001 an aerial survey with MIVIS (Multispectral Infrared and Visible Spectrometer hyperspectral sensor and an in situ survey campaign were performed on Venice lagoon to map benthic macro-algae and sea phanerogams distribution. On MIVIS VIS spectral range images, training areas for benthic macro-algae and sea phanerogams have been selected by using sea truth data collected by CNR-ISMAR from in situ campaign and periodic area surveys used in the lagoon by the local authorities. The derived spectral signature has been used to classify the area in order to produce the maps of the pure and mixture submersed vegetation population. The algorithm applied to the data is based on the Subpixel Spectral Analytical Process (SSAP method. The method assumes that the spectrum of a single pixel is composed of a fraction of the material of interest while the remainder of the observed spectra contains background materials. In terms of recognition processes the produced maps present a very good agreement with the sea truth data even though the fraction material expressed in the maps does not represent a quantitative estimation of the material of interest.

  1. Effects of ultraviolet radiation on pigmentation and malondialdehyde content of three aquatic macrophytes

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    Deep Chakraborty

    2014-05-01

    Full Text Available A study has been done in order to evaluate the ill effects of UV-A,UV-B and UV-C on pigmentation and malondialdehyde content of floating macrophytes (Lemna sp., Pistia sp. and Eichhornia sp. in one, three, and five days interval. Study results revealed that all types of ultraviolet light (UV-A, UV-B, and UV-C did not produce same extent of ill effects on the studied macrophytes. Pistia sp. and Eichhornia sp. showed similar reduction pattern of chl a/chl b ratio with respect to control. Results also suggest that among the three types of radiation only UV-B showed higher level of changes in both the pigment and malondialdehyde content. Moreover, among the three tested macrophytes only Lemna sp. showed some protective role against UV radiation compared to other to macrophytes.

  2. 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.

  3. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India

    OpenAIRE

    Amina Khatun; Sandipan Pal; Aloke Kumar Mukherjee; Palas Samanta; Subinoy Mondal; Debraj Kole; Priyanka Chandra; Apurba Ratan Ghosh

    2016-01-01

    Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophyte...

  4. 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.

  5. Oligochaeta (Annelida, Clitellata in the Aquatic Macrophytes in Dam of Ribeirão of Anhumas Screamers (Américo Brasiliense-Sp

    Directory of Open Access Journals (Sweden)

    Nathalie Aparecida De Oliveira Sanches

    2014-06-01

    Full Text Available Macrophytes have different morphological structural complexities, offering to animals the availability of various niches. These plants are also an important substrate for the development of periphyton, which has a high nutritional value and is one of the main foods of aquatic invertebrates, mainly Naididae. This study aimed at examinining the diversity of Oligochaeta community in macrophytes belonging to genus Egeria sp. and Salvinia sp., in lagoons of Ribeirão das Anhumas dam. These macrophytes have distinct three-dimensional characteristics and different habits, being Egeria fixed submerged and Salvinia free floating. The collections of macrophytes were carried out between the months of August 2012 and April 2013. Samples of 100g (wet weight of each genus were taken from plant biomass and the removal of the plants from the environment was made with the aid of a sieve with 0.21 mm mesh. Considering the two macrophytes analyzed, Egeria sp. was the one that presented greater diversity, richness and abundance in relation to Salvinia sp. These results demonstrate that macrophytes are important for the establishment of oligochaetes, mainly providing protection and food, and possibly the morphology and habit of the plants are the most influential factors in the association of oligofauna with these plants.

  6. Concentrations of zinc and chromium in aquatic macrophytes from the sudbury and muskoka regions of Ontario, Canada.

    Science.gov (United States)

    Reimer, P; Duthie, H C

    1993-01-01

    Root and shoot samples of Eriocaulon septangulare, Nuphar variegatum, Nymphaea odorata and Pontederia cordata were collected from 15 lakes in central Ontario during the summer of 1988 to investigate possible relationships between zinc and chromium levels in aquatic macrophytes and water and sediment variables. Although concentrations of zinc and chromium differed greatly among the four species, both metals were consistently higher in Eriocaulon. Generally, root and rhizome tissue contained higher zinc and chromium than shoot tissues of the same species and site. Zinc concentrations (dry weight) ranged from 6.3 microg g(-1) in Nuphar shoots to 87.7 microg g(-1) in whole Eriocaulon. Chromium ranged from 0.23 microg g(-1) in Pontederia shoots to 23.9 microg g(-1) in whole Eriocaulon. No significant trends were detected throughout the growing season in macrophyte or sediment concentrations of either metal. Results of multiple linear regression analyses of several water quality and environmental variables on Eriocaulon indicated that sediment zinc was the best predictor of plant zinc, and sediment chromium and calcium were the best predictors of plant chromium.

  7. Study of aquatic macrophytes in the wetlands on the territory of Vrachanski Balkan nature park

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    Valčev Vladimir V.

    2010-01-01

    Full Text Available An overall study of the species composition and abundance of macrophytes in all open water bodies of a large protected territory was made for the first time in Bulgaria. Four high-mountain eutrophic lakes and the upper stretches of three rivers within the boundaries of Vrachanski Balkan Nature Park were investigated. Thirty-nine macrophyte species (higher plants and mosses were identified scattered around, or forming more or less distinct vegetation groups. Three of the lakes are new for the country locations of the species Elatine alsinastrum and Peplis portula. The processes of eutrophication are more advanced in the lakes. The habitats formed around the investigated water bodies have been determined. They are three habitats of European Community interest for Bulgaria. The major threats for the investigated wetlands on the territory of the Park are pointed out.

  8. Quantitative and qualitative characteristics of dissolved organic matter from eight dominant aquatic macrophytes in Lake Dianchi, China.

    Science.gov (United States)

    Qu, Xiaoxia; Xie, Li; Lin, Ying; Bai, Yingchen; Zhu, Yuanrong; Xie, Fazhi; Giesy, John P; Wu, Fengchang

    2013-10-01

    The aim of this research was to determine and compare the quantitative and qualitative characteristics of dissolved organic matters (DOM) from eight aquatic macrophytes in a eutrophic lake. C, H, N, and P in ground dry leaves and C, N, and P in DOM of the species were determined, and C/N, C/P, C/H, DOC/C, TDN/N, TDP/P, DOC/TDN, and DOC/TDP were calculated. Chemical structures of the DOM were characterized by the use of multiple techniques including UV-visible, FT-IR, and (13)C CP/MAS spectra. The results showed subtle differences in quantity and quality of DOM among species and life-forms. Except oriental pepper which had a C/H of 0.7, C/H of all the other species was 0.6. C/N and C/P of ground leaves was 10.5-17.3 and 79.4-225.3, respectively, which were greater in floating and submerged species than in the others. Parrot feather also had a small C/P (102.8). DOC/C, TDN/N, and TDP/P were 7.6-16.8, 5.5-22.6, and 22.9-45.6 %, respectively. Except C/N in emergent and riparian species, C/N in the other species and C/P in all the species were lower in their DOM than in the ground leaves. DOM of the macrophytes had a SUVA254 value of 0.83-1.80. The FT-IR and (13)C NMR spectra indicated that the DOM mainly contained polysaccharides and/or amino acids/proteins. Percent of carbohydrates in the DOM was 37.3-66.5 % and was highest in parrot feather (66.5 %) and crofton weed (61.5 %). DOM of water hyacinth, water lettuce, and sago pondweed may have the greatest content of proteins. Aromaticity of the DOM was from 6.9 % in water lettuce to 17.8 % in oriental pepper. DOM of the macrophytes was also different in polarity and percent of Ar-OH. Distinguished characteristics in quantity and quality of the macrophyte-derived DOM may induce unique environmental consequences in the lake systems.

  9. Net primary productivity of some aquatic macrophytes in sewage-sullage mixture.

    Science.gov (United States)

    Kanungo, V K; Sinha, S; Naik, M L

    2001-07-01

    Sewage-sullage mixture from Raipur city is spread over a vast area surrounding the city. This mixture has a pH always above neutrality with high turbidity. Transparency was nil with the absence of phenolphthalein alkalinity and dissolved oxygen. Hardness was high with low nitrogen and phosphorus concentration. Human consumable. acquatic macrophytes are cultivated in such waste water. Net primary productivity of three macrophytes: Ipomoea aquatica, Marsilea quadrifolia and Nelumbo nucifera were evaluated while being cultivated in such sewage-sullage mixture. Productivity was determined either with periodic biomass removal (I. aquatica and M. quadrifolia) or through removing the biomass only once at the time of growing season (N. nucifera). Growing season productivity of up to 27.48. 19.81 and 9.49 g m(-2) and day(-1) and extrapolated productivity of up to 100.30, 72.31 and 34.64 mt. ha(-1) yr(-1) was recorded for I. aquatica. M. quadrifolia and N. nucifera respectively. Thus, these macrophytes are yielding a high amount of human consumable biomass from an area which neither be a useless wetland.

  10. The remote sensing of aquatic macrophytes Part 1: Color-infrared aerial photography as a tool for identification and mapping of littoral vegetation. Part 2: Aerial photography as a quantitative tool for the investigation of aquatic ecosystems. [Lake Wingra, Wisconsin

    Science.gov (United States)

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

    1973-01-01

    Research was initiated to use aerial photography as an investigative tool in studies that are part of an intensive aquatic ecosystem research effort at Lake Wingra, Madison, Wisconsin. It is anticipated that photographic techniques would supply information about the growth and distribution of littoral macrophytes with efficiency and accuracy greater than conventional methods.

  11. Floating Aquatic Macrophytes Decrease the Methane Concentration in the Water Column of a Tropical Coastal Lagoon: Implications for Methane Oxidation and Emission

    Directory of Open Access Journals (Sweden)

    André Luiz dos Santos Fonseca

    2017-05-01

    Full Text Available ABSTRACT In wetlands, the knowledge accumulated on the role of aquatic plants in the methane cycle focused on emergent macrophytes, to the detriment of other typologies. Herein, we evaluated whether the free-floating macrophyte Salvinia auriculata Aubl. and the floating-leaved macrophyte Eichhornia azurea (Sw. Kunth. decrease the water column methane concentrations compared to a plant-free surface. We prepared microcosms by inserting an individual of S. auriculata or of E. azurea into chambers filled with lagoon water previously bubbled with CH4. Another set of chambers was incubated only with the prepared water, representing the plant-free surface. Half of the chambers were kept in the dark and half in sunlight to simulate a diel cycle. We observed greater loss of CH4, higher O2 uptake and lower CO2 outflow in the plants treatments. The decrease in methane concentrations in the E. azurea treatments was 93.5% in the light and 77.2% in the dark. In the S. auriculata treatments, the decreases were 74.2% and 67.4% in the light and in the dark, respectively. In plant-free surface the decrease was 58.7% in the light and 36.3% in the dark. These results indicate a role of floating aquatic macrophytes in the methane cycle in the water column. Moreover, our results suggest a diel variation of methane oxidation and methane emission, according to the differences observed in O2 uptake and CO2 outflow between dark and light conditions. Thus, future predictions of global methane budget should include the role played by floating aquatic macrophytes.

  12. Biomass allocation to anchoring structures in the aquatic macrophytes from the subcontinental and Atlantic climates in Europe

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    Józef Szmeja

    2011-01-01

    Full Text Available Biomass allocation to anchoring structures in 10 species of aquatic macrophytes in two types of the cool and humid temperate climate in Europe, subcontionental (NW Poland and Atlantic (W France, was examined. The study focused on the weight of anchoring organs in Chara delicatula Ag., Ch. fragilis Desv., Juncus bulbosus L., Littorella uniflora (L. Asch., Luronium natans (L. Raf., Potamogeton pectinatus L., P. perfoliatus L., P. natans L. and Ranunculus fluitans (Lam. Wimm., as well as submerged structures in Hydrocharis morsus-ranae L. The plants were collected from 10 geographically distant lakes and 2 rivers with a current velocity of 0.3-0.5 m s-1. It was assumed that biomass allocation to anchoring structures in rooting macrophytes depends on the time that mechanical forces, which can remove the plants from the occupied area, exert their effect. It was found that, in the Atlantic and subcontinental climates, the ratio between the biomass of underground (or submerged and above-ground structures (U/A index, calculated for the ramets of Chara fragilis, Hydrocharis morsus-ranae and Ranunculus fluitans, has similar values (p>0.05. Nevertheless, among seven species of Cormophyta, which were anchored in the lake or pond littoral, six (Juncus bulbosus, Littorella uniflora, Luronium natans, Potamogeton pectinatus, P. perfoliatus and P. natans had higher values of the U/A index in the Atlantic climate than in the subcontinental type (p < 0.05. This can be explained by the lack of ice cover and, consequently, a longer time of wave action than in the subcontinental climate.

  13. ALLELOPATHIC EFFECTS OF NATIVE AND INVASIVE FRESHWATER MACROPHYTES ON PHYTOPLANKTON AND AQUATIC INVERTEBRATES

    OpenAIRE

    FARIBA MOSLIH PAKDEL

    2017-01-01

    Invasive freshwater plants impose extensive negative impacts on different biota. They usually form mono-specific stands that provide a less suitable habitat than mix stands, or may produce novel chemicals that can have deleterious and deterrent effects for native aquatic species. I tested the bioactivity of three invasive aquatic plants on different biota. My study demonstrated that several interrelated mechanisms used by invasive plants are responsible for the success of these species. For i...

  14. Fungal endophytes of aquatic macrophytes: diverse host-generalists characterized by tissue preferences and geographic structure

    OpenAIRE

    Sandberg, Dustin C.; Battista, Lorna J.; Arnold, A. Elizabeth

    2014-01-01

    Most studies of endophytic symbionts have focused on terrestrial plants, neglecting the ecologically and economically important plants present in aquatic ecosystems. We evaluated the diversity, composition, host- and tissue affiliations, and geographic structure of fungal endophytes associated with common aquatic plants in northern Arizona, USA. Endophytes were isolated in culture from roots and photosynthetic tissues during two growing seasons. A total of 226 isolates representing 60 putativ...

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

    Science.gov (United States)

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

    2008-01-01

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

  16. Aquatic macrophytes as indicators of water quality in subtropical shallow lakes, Southern Brazil Macrófitas aquáticas como indicadores da qualidade da água em pequenos lagos rasos subtropicais, Sul do Brasil

    Directory of Open Access Journals (Sweden)

    Sabrina Amaral Pereira

    2012-03-01

    Full Text Available AIMS: We evaluated the potential of aquatic macrophyte communities as bioindicators in six small shallow lakes. METHODS: The sampling was conducted monthly for one year, during which all macrophytes were surveyed, and the water temperature, dissolved oxygen, pH, conductivity, total alkalinity, chlorophyll-a, suspended matter, total nitrogen (Nt and total phosphorus (Pt were measured. RESULTS: In total, forty-three species were recorded, and there were significant differences in the species richness and limnological conditions among the lakes studied. A canonical correspondence analysis showed that the concentration of nutrients (Nt and Pt, chlorophyll-a, suspended matter, dissolved oxygen and pH were the most important predictors of the distribution of macrophytes. Some emergents were related to the high concentration of nutrients, chlorophyll-a, and suspended matter. Moreover, the most submersed species were associated with environments with low nutrient concentrations and the lowest values chlorophyll-a and suspended matter. In addition, some species submerged and floating were related to low values pH, alkalinity and dissolved oxygen. Limnological differences between lakes may be cited as the main causes of the observed heterogeneous distribution of macrophytes. CONCLUSIONS: These results indicate the importance of limnological characteristics of the different environments in the macrophyte community composition and the potential role of this community as a bioindicator in shallow lakes in southern Brazil.OBJETIVO: Foi avaliado o potencial bioindicador da comunidade de macrófitas aquáticas em seis pequenos lagos rasos. MÉTODOS: O acompanhamento foi mensal durante um ano, sendo que em cada coleta, além do registro de todas as espécies de macrófitas foram determinadas a temperatura da água, oxigênio dissolvido, pH, condutividade elétrica, alcalinidade total, clorofila-a, material em suspensão, nitrogênio total (Nt e fósforo total

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

    Science.gov (United States)

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

  18. Gene flow and genetic structure of the aquatic macrophyte Sparganium emersum in a linear unidirectional river

    NARCIS (Netherlands)

    Pollux, B.J.A.; Luteijn, A.W.W.; Van Groenendael, J.M.; Ouborg, N.J.

    2009-01-01

    1. River systems offer special environments for the dispersal of aquatic plants because of the unidirectional (downstream) flow and linear arrangement of suitable habitats. 2. To examine the effect of this flow on microevolutionary processes in the unbranched bur-reed (Sparganium emersum) we studied

  19. Fungal endophytes of aquatic macrophytes: diverse host-generalists characterized by tissue preferences and geographic structure.

    Science.gov (United States)

    Sandberg, Dustin C; Battista, Lorna J; Arnold, A Elizabeth

    2014-05-01

    Most studies of endophytic symbionts have focused on terrestrial plants, neglecting the ecologically and economically important plants present in aquatic ecosystems. We evaluated the diversity, composition, host and tissue affiliations, and geographic structure of fungal endophytes associated with common aquatic plants in lentic waters in northern Arizona, USA. Endophytes were isolated in culture from roots and photosynthetic tissues during two growing seasons. A total of 226 isolates representing 60 putative species was recovered from 9,600 plant tissue segments. Although isolation frequency was low, endophytes were phylogenetically diverse and species-rich. Comparisons among the most thoroughly sampled species and reservoirs revealed that isolation frequency and diversity did not differ significantly between collection periods, among species, among reservoirs, or as a function of depth. However, community structure differed significantly among reservoirs and tissue types. Phylogenetic analyses of a focal genus (Penicillium) corroborated estimates of species boundaries and informed community analyses, highlighting clade- and genotype-level affiliations of aquatic endophytes with both sediment- and waterborne fungi, and endophytes of proximate terrestrial plants. Together these analyses provide a first quantitative examination of endophytic associations in roots and foliage of aquatic plants and can be used to optimize survey strategies for efficiently capturing fungal biodiversity at local and regional scales.

  20. The response of stream fish to local and reach-scale variation in the occurrence of a benthic aquatic macrophyte

    Science.gov (United States)

    Argentina, J.E.; Freeman, Mary C.; Freeman, B.J.

    2010-01-01

    The aquatic macrophyte Podostemum ceratophyllum has been shown to increase stream productivity, abundance and biomass of benthic invertebrates, and local occurrences of some stream fishes. However, experimental evidence that fishes preferentially associate with Podostemum is lacking, and the value of Podostemum as a predictor of stream fish assemblage composition has not been studied. We conducted two short-term (2 week), small-scale (36 m2) experimental manipulations of Podostemum cover in the Conasauga River (Georgia and Tennessee, U.S.), and found higher abundances of benthic insectivorous fishes in patches with augmented (>80%) compared to reduced (7%) Podostemum cover. In an observational study, we quantified associations among percent cover of Podostemum, fish species richness, land cover, shoal length and base-flow turbidity at 20 randomly selected shoals from a 39-km reach that spanned a gradient of decreasing forest land cover.Richness of all fish species and of lotic fishes peaked in the centre of the study reach, and richness was weakly correlated with predictor variables. Occupancy models for individual species also indicated that longitudinal position was a strong covariate for 13 of 19 species examined, with little support that Podostemum cover influenced occupancy. Local associations may reflect choices by benthic fishes to utilise Podostemum, whereas downstream decline in fish species richness and Podostemum cover may reflect altered capacity of the system to support native species. Published 2009. This article is a US Government work and is in the public domain in the USA.

  1. The influence of aquatic macrophytes on distribution and feeding habit of two Asplanchna species (A. priodonta and A. herrickii in shallow wetlands, South Korea

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    Jong-Yun Choi

    2014-06-01

    Full Text Available We tested the hypothesis that the spatial distribution and diet composition of Asplanchna species might be affected by the presence of aquatic macrophytes in 33 wetlands in South Korea. We estimated the densities of Asplanchna and other rotifer and crustacean, together with environmental parameters, in both vegetated and open water zones, from May to June 2011. In the present study, two species of Asplanchna, A. priodonta and A. herrickii, were observed and significantly more abundant in open water zones lacking macrophytes. In particular, the density of A. priodonta was higher than that of A. herrickii, and the density of A. priodonta was strongly positively correlated with the area of open water. In addition, gut content analysis was used to determine their dietary preferences, with the finding that there was apparent differentiation in food source utilisation between the two Asplanchna species; A. priodonta consumed some protozoa, phytoplankton, and exclusively pelagic rotifer, while A. herrickii consumed primarily Euglena. In particular, Keratella and Polyarthra were most commonly consumed by A. priodonta in open water. Macrophytes represent a suitable habitat for epiphytic rotifer but not for pelagic rotifer; this characteristic drives pelagic rotifer such as Asplanchna towards open water and may be responsible for the significant negative correlation that we observed between macrophyte and Asplanchna densities.

  2. Characteristics and degradation of carbon and phosphorus from aquatic macrophytes in lakes: Insights from solid-state {sup 13}C NMR and solution {sup 31}P NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shasha [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhu, Yuanrong, E-mail: zhuyuanrong07@mails.ucas.ac.cn [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Meng, Wei, E-mail: mengwei@craes.org.cn [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); He, Zhongqi [USDA-ARS Southern Regional Research Center, 1100 Robert E Lee Blvd, New Orleans, LA 70124 (United States); Feng, Weiying [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhang, Chen [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Giesy, John P. [State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Department of Biomedical and Veterinary Biosciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    2016-02-01

    Water extractable organic matter (WEOM) derived from macrophytes plays an important role in biogeochemical cycling of nutrients, including carbon (C), nitrogen (N) and phosphorus (P) in lakes. However, reports of their composition and degradation in natural waters are scarce. Therefore, compositions and degradation of WEOM derived from six aquatic macrophytes species of Tai Lake, China, were investigated by use of solid-state {sup 13}C NMR and solution {sup 31}P NMR spectroscopy. Carbohydrates were the predominant constituents of WEOM fractions, followed by carboxylic acid. Orthophosphate (ortho-P) was the dominant form of P (78.7% of total dissolved P) in the water extracts, followed by monoester P (mono-P) (20.6%) and little diester P (0.65%). The proportion of mono-P in total P species increased with the percentage of O-alkyl and O–C–O increasing in the WEOM, which is likely due to degradation and dissolution of biological membranes and RNA from aquatic plants. Whereas the proportion of mono-P decreased with alkyl-C, NCH/OCH{sub 3} and COO/N–C=O increasing, which may be owing to the insoluble compounds including C functional groups of alkyl-C, NCH/OCH{sub 3} and COO/N–C=O, such as aliphatic biopolymers, lignin and peptides. Based on the results of this study and information in the literature about water column and sediment, we propose that WEOM, dominated by polysaccharides, are the most labile and bioavailable component in debris of macrophytes. Additionally, these WEOMs would also be a potential source for bioavailable organic P (e.g., RNA, DNA and phytate) for lakes. - Highlights: • WEOM derived from aquatic macrophytes was characterized. • C and P in WEOM were characterized by solid {sup 13}C NMR and solution {sup 31}P NMR. • Degradation and transformation of macrophyte-derived C and P were investigated. • Macrophyte-derived WEOM are important source for bioavailable nutrients in lakes.

  3. The characterization of axenic culture systems suitable for plant propagation and experimental studies of the submersed aquatic angiosperm Potamogeton pectinatus (Sago pondweed)

    Science.gov (United States)

    Ailstock, M.S.; Fleming, W.J.; Cooke, T.J.

    1991-01-01

    Clonal lines of the submersed aquatic angiosperm Potamogeton pectinatus were grown in three culture systems. The first, which used sucrose as a carbon source in a liquid medium, supported vigorous vegetative growth and can be used to propagate large numbers of plants in axenic conditions. In this culture system, plants were responsive to increasing photosynthetically active radiation (PAR) photon flux density (PFD) and were photosynthetically competent. However, their growth was heterotrophic and root development was poor. When these plants were transferred to a second nonaxenic culture system, which used 16-l buckets containing artificial sediments and tap water, growth was autotrophic and plants were morphologically identical to field-harvested P. pectinatus. The last culture system which consisted of a sand substrate and inorganic nutrient bathing solution aerated with 135 ml min-1 ambient air enhanced to 3.0% CO2 was axenic and supported autotrophic growth by plants that were also morphologically normal.

  4. Artificial regulation of water level and its effect on aquatic macrophyte distribution in Taihu Lake.

    Directory of Open Access Journals (Sweden)

    Dehua Zhao

    Full Text Available Management of water levels for flood control, water quality, and water safety purposes has become a priority for many lakes worldwide. However, the effects of water level management on the distribution and composition of aquatic vegetation has received little attention. Relevant studies have used either limited short-term or discrete long-term data and thus are either narrowly applicable or easily confounded by the effects of other environmental factors. We developed classification tree models using ground surveys combined with 52 remotely sensed images (15-30 m resolution to map the distributions of two groups of aquatic vegetation in Taihu Lake, China from 1989-2010. Type 1 vegetation included emergent, floating, and floating-leaf plants, whereas Type 2 consisted of submerged vegetation. We sought to identify both inter- and intra-annual dynamics of water level and corresponding dynamics in the aquatic vegetation. Water levels in the ten-year period from 2000-2010 were 0.06-0.21 m lower from July to September (wet season and 0.22-0.27 m higher from December to March (dry season than in the 1989-1999 period. Average intra-annual variation (CV(a decreased from 10.21% in 1989-1999 to 5.41% in 2000-2010. The areas of both Type 1 and Type 2 vegetation increased substantially in 2000-2010 relative to 1989-1999. Neither annual average water level nor CV(a influenced aquatic vegetation area, but water level from January to March had significant positive and negative correlations, respectively, with areas of Type 1 and Type 2 vegetation. Our findings revealed problems with the current management of water levels in Taihu Lake. To restore Taihu Lake to its original state of submerged vegetation dominance, water levels in the dry season should be lowered to better approximate natural conditions and reinstate the high variability (i.e., greater extremes that was present historically.

  5. Artificial regulation of water level and its effect on aquatic macrophyte distribution in Taihu Lake.

    Science.gov (United States)

    Zhao, Dehua; Jiang, Hao; Cai, Ying; An, Shuqing

    2012-01-01

    Management of water levels for flood control, water quality, and water safety purposes has become a priority for many lakes worldwide. However, the effects of water level management on the distribution and composition of aquatic vegetation has received little attention. Relevant studies have used either limited short-term or discrete long-term data and thus are either narrowly applicable or easily confounded by the effects of other environmental factors. We developed classification tree models using ground surveys combined with 52 remotely sensed images (15-30 m resolution) to map the distributions of two groups of aquatic vegetation in Taihu Lake, China from 1989-2010. Type 1 vegetation included emergent, floating, and floating-leaf plants, whereas Type 2 consisted of submerged vegetation. We sought to identify both inter- and intra-annual dynamics of water level and corresponding dynamics in the aquatic vegetation. Water levels in the ten-year period from 2000-2010 were 0.06-0.21 m lower from July to September (wet season) and 0.22-0.27 m higher from December to March (dry season) than in the 1989-1999 period. Average intra-annual variation (CV(a)) decreased from 10.21% in 1989-1999 to 5.41% in 2000-2010. The areas of both Type 1 and Type 2 vegetation increased substantially in 2000-2010 relative to 1989-1999. Neither annual average water level nor CV(a) influenced aquatic vegetation area, but water level from January to March had significant positive and negative correlations, respectively, with areas of Type 1 and Type 2 vegetation. Our findings revealed problems with the current management of water levels in Taihu Lake. To restore Taihu Lake to its original state of submerged vegetation dominance, water levels in the dry season should be lowered to better approximate natural conditions and reinstate the high variability (i.e., greater extremes) that was present historically.

  6. Anatomy of the root of eight species of emergent aquatic macrophytes from the upper Paraná river, Paraná State, Brazil floodplain - doi: 10.4025/actascibiolsci.v32i3.5509 Anatomy of the root of eight species of emergent aquatic macrophytes from the upper Paraná river, Paraná State, Brazil floodplain - doi: 10.4025/actascibiolsci.v32i3.5509

    Directory of Open Access Journals (Sweden)

    Angela Maria Marques Sanches Marques

    2010-09-01

    Full Text Available The upper Paraná River floodplain is characterized by the existence of several aquatic and transitional habitats between the aquatic and terrestrial environment, influencing the presence and distribution of aquatic macrophytes. Samples were taken from different places and permanent slides were prepared for analysis and capture of images with the objective of comparing the anatomy of the roots of eight species of emergent aquatic macrophytes. The species feature uniseriate epidermis with narrow and long cells, cortex composed of uniseriate or biseriate exodermis, with or without thickening, aerenchyma with great gaps, uniseriate endodermis, with or without thickening, continuous or interrupted pericycle, and central cylinder with variable number of xylem poles.The upper Paraná River floodplain is characterized by the existence of several aquatic and transitional habitats between the aquatic and terrestrial environment, influencing the presence and distribution of aquatic macrophytes. Samples were taken from different places and permanent slides were prepared for analysis and capture of images with the objective of comparing the anatomy of the roots of eight species of emergent aquatic macrophytes. The species feature uniseriate epidermis with narrow and long cells, cortex composed of uniseriate or biseriate exodermis, with or without thickening, aerenchyma with great gaps, uniseriate endodermis, with or without thickening, continuous or interrupted pericycle, and central cylinder with variable number of xylem poles.

  7. Richness and distribution of aquatic macrophytes in Brazilian semi-arid aquatic ecosystems Riqueza e distribuição de macrófitas aquáticas em ecossistemas aquáticos do semi-árido brasileiro

    Directory of Open Access Journals (Sweden)

    Gustavo Gonzaga Henry-Silva

    2010-06-01

    Full Text Available AIM: The aim of this study was to evaluate the richness and distribution of the aquatic macrophytes in the basin of the Apodi/Mossoró River, in the semi-arid region (caatinga of Rio Grande do Norte, Brazil; METHODS: A survey of the floristic composition of the aquatic macrophytes was made at 20 sampling stations in the basin at four seasons (August/2007, November/2007, February/2008, May/2008. Specimens of each species were collected and deposited in the Dárdano de Andrade Lima Herbarium of the Universidade Federal Rural do Semi-Árido; RESULTS: We found 40 species of aquatic macrophytes, in 33 genera and 22 families. The families with the most species were Poaceae and Cyperaceae, and the most species-rich genera were Cyperus and Eleocharis. The most common plant form was amphibian (42.5%, followed by emergent (27.5%, free-floating (12.5%, rooted-submersed (10.0%, and floating-leaved (7.5%. The lowest richness was observed at the estuarine region (3 species, and the highest richness in the upper basin (17 species. The rooted-submersed Hydrothrix gardneri Hooker f. and Ceratophyllum demersum L. were observed in great abundance and frequency in the Santa Cruz Reservoir of Apodi, especially in areas close to cage farms of Nile tilapia (Oreochromis niloticus (Linnaeus, 1758. The most common free-floating species were Eichhornia crassipes (Mart. Solms., Pistia stratiotes L., and Salvinia auriculata Aubl., predominantly in stretches that run through urban centers; CONCLUSION: The species richness of aquatic macrophytes in aquatic environments of the caatinga is similar to that observed in other basins of Brazil. Because of the many dams and reservoirs in the semi-arid Northeast, inventory and monitoring of aquatic macrophytes have become essential, especially in basins that will receive water from the diversion of the São Francisco River.OBJETIVO: Nós objetivamos avaliar a riqueza e a distribuição das macrófitas aquáticas nos ambientes aqu

  8. Aquatic Macrophytes as Microhabitats of Radix auricularia (Gastropoda: Pulmonata: A Case Study from Southeast Bulgaria

    Directory of Open Access Journals (Sweden)

    Stanislava Y. Vasileva

    2009-07-01

    Full Text Available The aim of the current study is to investigate the abundance of thefreshwater pulmonate snail Radix auricularia among different aquatic plants communities, with the view of understanding if there is any particular habitat preference, comparing two freshwater basins having similar environmental conditions. The freshwater plant species were collected by net from two ponds at the end of May 2009 - 650 g wet plant mass, micro dam at Chernoochene Village, East Rhodopes Mts.; 138 g wet plant mass, small flood pond near the Maritza River, Plovdiv City, Upper Thracian Lowland. The plant mass was weighted in the laboratory after the alive snails were collected from the plant surface. Totally three species of freshwater plants were inhabited by R. auricularia, but its abundance and possible preference was highest on the Rigid Hornworth (Ceratophyllum demersum.

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

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2014-08-01

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

  10. Cadmium and lead bioaccumulation potentials of an aquatic macrophyte Ceratophyllum demersum L.: A laboratory study.

    Science.gov (United States)

    Dogan, Muhammet; Karatas, Mehmet; Aasim, Muhammad

    2018-02-01

    Cadmium (Cd) and lead (Pb) pollutions caused by industrial activities are one of the most serious threats to aquatic ecosystems. The aim of this study is to investigate the Cd and Pb bioaccumulations and diverse physiological and biochemical properties of Ceratophyllum demersum L. exposed to different concentrations of Cd (0.5-2.0mg/L) and Pb (25-100mg/L) in aqueous media for 1, 3 and 5 days. Cd and Pb accumulations increased with increase in the exposure times and concentrations, and the highest accumulation values of Cd and Pb were recorded at 2mg/L (2668.33mg/kg dw) and 100mg/L (22,504.10mg/kg dw), respectively, after 5 days. However, higher bioconcentration factors (BCF) were calculated as 645.43 at 25mg/L Pb and as 1357.92 at 1mg/L Cd after 5 days. The results showed that photosynthetic pigments (chlorophyll a, b and carotenoids) and protein contents of the plants exposed to Cd and Pb toxicities decreased with increasing metal concentration and exposure time, whereas their malondialdehyde (MDA) contents increased. Additionally, the single and synergistic effects of duration and metal concentration on the fresh and dry weights of the plant were determined. The results of this study reveal that C. demersum, propagated by tissue culture technique, can be used effectively in the phytoremediation of aquatic environments contaminated by Cd and Pb. This study will also make a positive contribution to the progression of new phytotechnologies on the purpose of the remediation of wastewater by plants in future. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Phytoremediation of organochlorine and pyrethroid pesticides by aquatic macrophytes and algae in freshwater systems.

    Science.gov (United States)

    Riaz, Ghazala; Tabinda, Amtul Bari; Iqbal, Shakir; Yasar, Abdullah; Abbas, Mateen; Khan, Abdul Muqeet; Mahfooz, Yusra; Baqar, Mujtaba

    2017-10-03

    Extensive use of Pesticides in agriculture and its surface runoff in river water is a major environmental concern. The present study evaluated the phytoremediation potential of Eichornia crassipes, Pistia strateotes and algae (Chaetomorpha sutoria, Sirogonium sticticum and Zygnema sp.) for organochlorine and pyrethroid pesticides. Water and plant samples were extracted by liquid phase and solid phase extraction respectively and analyzed by high-performance liquid chromatography. Eleven treatments (T1-T11) with and without plants were used for phytoremediation of organochlorine and pyrethroid pesticides. During the experiment, P. strateotes, E. crassipes and algae (C. sutoria, S. sticticum and Zygnema sp.) showed the highest removal efficiency with 62 (71% root, 29% shoot), 60 (67% root, 33% shoot), and 58% respectively for organochlorine and 76 (76% root, 24% shoot), 68 (69% root, 31% shoot), and 70% respectively for pyrethroids for the respective aquatic plants. Dissipation rate constant of treatments with plants (T2, T3, T5, T6, T8, and T9) was significantly higher (p plants (T10 and T11, control) for both organochlorine and pyrethroid. The bioconcentration factor of pyrethroid treatments (T3, T6, and T9) was significantly higher (p < 0.05) as compared to that of organochlorine treatments (T2, T5 and T8). The removal efficiency of E. crassipes, P. strateotes and algae (C. sutoria, S. sticticum and Zygnema sp.) for pyrethroids was significantly higher (p < 0.01) as compared to that of organochlorine.

  12. Copper-induced response of physiological parameters and antioxidant enzymes in the aquatic macrophyte Potamogeton pusillus

    Energy Technology Data Exchange (ETDEWEB)

    Monferran, Magdalena V.; Sanchez Agudo, Jose A. [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica - CIBICI, Medina Allende Esq., Haya de la Torre, Ciudad Universitaria, 5000 Cordoba (Argentina); Pignata, Maria L. [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Exactas, Fisicas y Naturales - IMBIV, Ciudad Universitaria, 5000 Cordoba (Argentina); Wunderlin, Daniel A., E-mail: dwunder@fcq.unc.edu.a [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica - CIBICI, Medina Allende Esq., Haya de la Torre, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2009-08-15

    Bioaccumulation and toxicity of copper was evaluated on Potamogeton pusillus L. The effect of copper (5-100 mug L{sup -1}) applied for several days was assessed by measuring changes in the chlorophyll's, phaeophytin's, malondialdehyde, electrical conductivity, glutathione peroxidase (GPX), glutathione reductase (GR) and guaiacol peroxidase (POD) activities. Plants accumulated copper with a maximum of 162 mug g{sup -1} dw after 7-days exposure at 100 mug L{sup -1}, however most of the metal was accumulated after 1-day exposure. The toxic effect caused by Cu was evident by the reduction of photosynthetic pigments, increase of malondialdehyde and electrical conductivity. P. pusillus shows Cu-induced oxidative stress by modulating antioxidant enzymes like GPX, GR and POD. Antioxidant enzymes activity increased significantly after exposure to 40 mug L{sup -1} during 24 h, followed by a drop at longer times. Thus, P. pusillus is proposed as a good biomonitor for the assessment of metal pollution in aquatic ecosystems. - The tolerance of Potamogeton pusillus to copper largely depends on the enhanced activity of its antioxidant system, showing that a decrease on its activity favored oxidative stress and cell damage.

  13. Arbuscular Mycorrhizal and Dark Septate Endophyte Fungal Associations in South Indian Aquatic and Wetland Macrophytes

    Directory of Open Access Journals (Sweden)

    Kumar Seerangan

    2014-01-01

    Full Text Available Investigations on the prevalence of arbuscular mycorrhizal (AM and dark septate endophyte (DSE fungal symbioses are limited for plants growing in tropical aquatic and wetland habitats compared to those growing on terrestrial moist or dry habitats. Therefore, we assessed the incidence of AM and DSE symbiosis in 8 hydrophytes and 50 wetland plants from four sites in south India. Of the 58 plant species examined, we found AM and DSE fungal symbiosis in 21 and five species, respectively. We reported for the first time AM and DSE fungal symbiosis in seven and five species, respectively. Intermediate-type AM morphology was common, and AM morphology is reported for the first time in 16 plant species. Both AM and DSE fungal colonization varied significantly across plant species and sites. Intact and identifiable AM fungal spores occurred in root zones of nine plant species, but AM fungal species richness was low. Though no clear relationship between AM and DSE fungal colonization was recognized, a significant negative correlation between AM colonization and spore numbers was established. Our study suggests that the occurrence of AM and DSE fungal symbiosis in plants growing in hydrophytic and wetland habitats is not as common as in terrestrial habitats.

  14. Characteristics and degradation of carbon and phosphorus from aquatic macrophytes in lakes: Insights from solid-state (13)C NMR and solution (31)P NMR spectroscopy.

    Science.gov (United States)

    Liu, Shasha; Zhu, Yuanrong; Meng, Wei; He, Zhongqi; Feng, Weiying; Zhang, Chen; Giesy, John P

    2016-02-01

    Water extractable organic matter (WEOM) derived from macrophytes plays an important role in biogeochemical cycling of nutrients, including carbon (C), nitrogen (N) and phosphorus (P) in lakes. However, reports of their composition and degradation in natural waters are scarce. Therefore, compositions and degradation of WEOM derived from six aquatic macrophytes species of Tai Lake, China, were investigated by use of solid-state (13)C NMR and solution (31)P NMR spectroscopy. Carbohydrates were the predominant constituents of WEOM fractions, followed by carboxylic acid. Orthophosphate (ortho-P) was the dominant form of P (78.7% of total dissolved P) in the water extracts, followed by monoester P (mono-P) (20.6%) and little diester P (0.65%). The proportion of mono-P in total P species increased with the percentage of O-alkyl and O-C-O increasing in the WEOM, which is likely due to degradation and dissolution of biological membranes and RNA from aquatic plants. Whereas the proportion of mono-P decreased with alkyl-C, NCH/OCH3 and COO/N-C=O increasing, which may be owing to the insoluble compounds including C functional groups of alkyl-C, NCH/OCH3 and COO/N-C=O, such as aliphatic biopolymers, lignin and peptides. Based on the results of this study and information in the literature about water column and sediment, we propose that WEOM, dominated by polysaccharides, are the most labile and bioavailable component in debris of macrophytes. Additionally, these WEOMs would also be a potential source for bioavailable organic P (e.g., RNA, DNA and phytate) for lakes. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Spatial distribution and biomass of aquatic rooted macrophytes and their relevance in the metabolism of a Mediterranean coastal lagoon

    Directory of Open Access Journals (Sweden)

    Biel Obrador

    2007-03-01

    Full Text Available This work aims to characterise the current autotrophic compartment of the Albufera des Grau coastal lagoon (Menorca, Balearic Islands and to assess the relationship between the submerged macrophytes and the limnological parameters of the lagoon. During the study period the submerged vegetation was dominated by the macrophyte Ruppia cirrhosa, which formed dense extensive meadows covering 79% of the surface. Another macrophyte species, Potamogeton pectinatus, was also observed but only forming small stands near the rushing streams. Macroalgae were only occasionally observed. Macrophyte biomass showed a clear seasonal trend, with maximum values in July. The biomass of R. cirrhosa achieved 1760 g DW m-2, the highest biomass ever reported for this species in the literature. The seasonal production-decomposition cycle of the macrophyte meadows appears to drive the nutrient dynamics and carbon fluxes in the lagoon. Despite the significant biomass accumulation and the absence of a washout of nutrients and organic matter to the sea, the lagoon did not experience a dystrophic collapse. These results indicate that internal metabolism is more important than exchange processes in the lagoon.

  16. The plastid genome of Najas flexilis: adaptation to submersed environments is accompanied by the complete loss of the NDH complex in an aquatic angiosperm.

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    Elena L Peredo

    Full Text Available The re-colonization of aquatic habitats by angiosperms has presented a difficult challenge to plants whose long evolutionary history primarily reflects adaptations to terrestrial conditions. Many aquatics must complete vital stages of their life cycle on the water surface by means of floating or emergent leaves and flowers. Only a few species, mainly within the order Alismatales, are able to complete all aspects of their life cycle including pollination, entirely underwater. Water-pollinated Alismatales include seagrasses and water nymphs (Najas, the latter being the only freshwater genus in the family Hydrocharitaceae with subsurface water-pollination. We have determined the complete nucleotide sequence of the plastid genome of Najas flexilis. The plastid genome of N. flexilis is a circular AT-rich DNA molecule of 156 kb, which displays a quadripartite structure with two inverted repeats (IR separating the large single copy (LSC from the small single copy (SSC regions. In N. flexilis, as in other Alismatales, the rps19 and trnH genes are localized in the LSC region instead of within the IR regions as in other monocots. However, the N. flexilis plastid genome presents some anomalous modifications. The size of the SSC region is only one third of that reported for closely related species. The number of genes in the plastid is considerably less. Both features are due to loss of the eleven ndh genes in the Najas flexilis plastid. In angiosperms, the absence of ndh genes has been related mainly to the loss of photosynthetic function in parasitic plants. The ndh genes encode the NAD(PH dehydrogenase complex, believed essential in terrestrial environments, where it increases photosynthetic efficiency in variable light intensities. The modified structure of the N. flexilis plastid genome suggests that adaptation to submersed environments, where light is scarce, has involved the loss of the NDH complex in at least some photosynthetic angiosperms.

  17. Effects of nutrient additions and macrophyte composition on invertebrate community assembly and diversity in experimental ponds.

    NARCIS (Netherlands)

    Declerck, S.A.J.; Bakker, E.S.; van Lith, B.; Kersbergen, A.P.; Van Donk, E.

    2011-01-01

    Macrophytes and nutrient loading are two factors that can strongly determine the diversity and composition of aquatic invertebrate communities. Both factors may also interact, because macrophyte species may be differentially affected by nutrients. Macrophyte community characteristics, such as

  18. Mercury contents in aquatic macrophytes from two reservoirs in the Paraíba do Sul: Guandú river system, SE Brazil

    Directory of Open Access Journals (Sweden)

    M. M. Molisani

    Full Text Available This paper reports on a study to determine the Hg content in the five most abundant aquatic macrophyte species (Elodea densa, Sagittaria montevidensis, Salvinia auriculata, Pistia stratiotes and Eichhornia crassipes in two artificial reservoirs flooded by water diverted from the Paraíba do Sul river, SE Brazil. The potential of these species for Hg accumulation and their role in Hg transport along the river system due to macrophyte management were evaluated. Mercury concentrations were higher in free-floating than in rooted species. Roots were also richer in Hg than were leaves. Dry weight Hg concentrations in leaves and roots from all species varied from 46-246 ng.g-1 to 37-314 ng.g-1, respectively. These values are higher than those reported for uncontaminated lakes in Brazil and in other tropical areas and similar to those reported for moderately contaminated sites. Mercury concentrations can be attributed to fluvial transport from the heavily industrialized Paraíba do Sul river basin. Intensive sampling of Pistia stratiotes from two sites in the Vigário reservoir was performed to evaluate the capacity of Hg incorporation in short periods of time. The results showed a significant negative correlation between Hg content and size class of individual plants, demonstrating the importance of juveniles, fast growing plants in absorbing Hg. The foremost impact related to Hg contents in the studied area concerns the periodic removal of macrophytes for reservoir management, followed by disposal in nearby areas. This results in the mobilization of 0.52 to 1.3 Kg of Hg per year, a significant fraction of the Hg burden present in reservoir waters. Disposal of such material may result in Hg leaching to river systems, affecting the Hg transfer throughout the basin.

  19. Invasive Crayfish Threaten the Development of Submerged Macrophytes in Lake Restoration

    NARCIS (Netherlands)

    Wal, van der J.E.M.; Dorenbosch, M.; Immers, A.K.; Vidal Forteza, C.; Geurts Van Kessel, J.M.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  20. Invasive crayfish threaten the development of submerged macrophytes in lake restoration

    NARCIS (Netherlands)

    Van der Wal, J.E.M.; Dorenbosch, M.; Immers, A.; Vidal Forteza, C.; Geurts, J.J.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  1. Proceedings, Annual Meeting, Aquatic Plant Control Research Program (20th) Held at Atlanta, Georgia on 18-21 November 1985.

    Science.gov (United States)

    1986-06-01

    glyphosate , and fenatrol have been conducted in cooperation with industry to evaluate efficacy, environmental fate, and/or toxicology of these...interact with essentially equal importance in influencing the growth and morphology of submersed freshwater macrophytes. Differences in the morphological...supply in relation to the growth of submersed macrophytes. Significantly, the photosynthetic potential of a variety of submersed freshwater

  2. Reproductive strategy, clonal structure and genetic diversity in populations of the aquatic macrophyte Sparganium emersum in river systems

    NARCIS (Netherlands)

    Pollux, B.J.A.; de Jong, M.D.E.; Steegh, A.; Verbruggen, E.; Van Groenendael, J.M.; Ouborg, N.J.

    2007-01-01

    Many aquatic and riparian plant species are characterized by the ability to reproduce both sexually and asexually. Yet, little is known about how spatial variation in sexual and asexual reproduction affects the genotypic diversity within populations of aquatic and riparian plants. We used six

  3. The effect of seed morphology on the potential dispersal of aquatic macrophytes by the common carp (Cyprinus carpio)

    NARCIS (Netherlands)

    Pollux, B.J.A.; de Jong, M.D.E.; Steegh, A.; Ouborg, N.J.; Van Groenendael, J.M.; Klaassen, M.R.J.

    2006-01-01

    1. The potential for seed dispersal by fish (ichthyochory) will vary among aquatic plants because of differences in seed size and morphology. 2. To examine how seed morphology influences the probability of dispersal by the common carp (Cyprinus carpio), we studied seed ingestion, retention time and

  4. Monitoring to assess progress toward meeting the Assabet River, Massachusetts, phosphorus total maximum daily load - Aquatic macrophyte biomass and sediment-phosphorus flux

    Science.gov (United States)

    Zimmerman, Marc J.; Qian, Yu; Yong Q., Tian

    2011-01-01

    In 2004, the Total Maximum Daily Load (TMDL) for Total Phosphorus in the Assabet River, Massachusetts, was approved by the U.S. Environmental Protection Agency. The goal of the TMDL was to decrease the concentrations of the nutrient phosphorus to mitigate some of the instream ecological effects of eutrophication on the river; these effects were, for the most part, direct consequences of the excessive growth of aquatic macrophytes. The primary instrument effecting lower concentrations of phosphorus was to be strict control of phosphorus releases from four major wastewatertreatment plants in Westborough, Marlborough, Hudson, and Maynard, Massachusetts. The improvements to be achieved from implementing this control were lower concentrations of total and dissolved phosphorus in the river, a 50-percent reduction in aquatic-plant biomass, a 30-percent reduction in episodes of dissolved oxygen supersaturation, no low-flow dissolved oxygen concentrations less than 5.0 milligrams per liter, and a 90-percent reduction in sediment releases of phosphorus to the overlying water. In 2007, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, initiated studies to evaluate conditions in the Assabet River prior to the upgrading of wastewater-treatment plants to remove more phosphorus from their effluents. The studies, completed in 2008, implemented a visual monitoring plan to evaluate the extent and biomass of the floating macrophyte Lemna minor (commonly known as lesser duckweed) in five impoundments and evaluated the potential for phosphorus flux from sediments in impounded and free-flowing reaches of the river. Hydrologically, the two study years 2007 and 2008 were quite different. In 2007, summer streamflows, although low, were higher than average, and in 2008, the flows were generally higher than in 2007. Visually, the effects of these streamflow differences on the distribution of Lemna were obvious. In 2007, large amounts of

  5. Selenium accumulation in submerged aquatic macrophytes Potamogeton pectinatus L. and Ruppia maritima L. from water with elevated chloride and sulfate salinity.

    Science.gov (United States)

    Wu, Lin; Guo, Xun

    2002-01-01

    Submerged aquatic macrophyte species Potamogeton crispus L. (curlyleaf pondweed) and Ruppia maritima L. (widegeongrass) were examined for selenium accumulation from agricultural drainage water in the field and under laboratory conditions. High concentrations of chloride and sulfate salts were found in the drainage water of the constructed wetland at Tulare Lake Drainage District, Corcorn, California. Samples of P. crispus and R. maritima collected from the field, had similar plant-tissue Se concentrations, but the rhizomes accumulated significantly greater amounts of Se than the shoot tissues. When the plants were grown in culture solution supplemented with either chloride or sulfate salt, R. maritima was found to be more salt tolerant than P. crispus, and P. crispus accumulated more Se than R. maritima. Free seleno-amino acids were detected in the plant tissue, and organic Se was detected in the culture solution after 10 days of growth. The release of organic Se into the water by the plants may have a negative impact on the wetland environment.

  6. Bioelectricity generation, contaminant removal and bacterial community distribution as affected by substrate material size and aquatic macrophyte in constructed wetland-microbial fuel cell.

    Science.gov (United States)

    Wang, Junfeng; Song, Xinshan; Wang, Yuhui; Bai, Junhong; Bai, Heng; Yan, Dengming; Cao, Yin; Li, Yihao; Yu, Zhilei; Dong, Guoqiang

    2017-12-01

    Integrating microbial fuel cell with constructed wetland (CW-MFC) is a novel way to harvest bioelectricity during wastewater treatment. In this study, the bioelectricity generation, containment removal and microbial community distribution in CW-MFC as affected by substrate material sizes and aquatic macrophyte were investigated. The planted CW-MFC with larger filler size showed a significant promotion of the relative abundance of electrochemically active bacteria (beta-Proteobacteria), which might result in the increase of bioelectricity generation in CW-MFC (8.91mWm-2). Additionally, a sharp decrease of voltage was observed in unplanted CW-MFC with smaller filler size in Cycle eight. However, the peak COD (86.7%) and NO3-N (87.1%) removal efficiencies were observed in planted CW-MFC with smaller filler size, which was strongly related to the biodiversity of microorganisms. Generally, the acclimation of exoelectrogens as dominant microbes in the anode chamber of planted CW-MFC with larger filler size could promote the bioelectricity generation during wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effects of Acid Stress on Aerobic Decomposition of Algal and Aquatic Macrophyte Detritus: Direct Comparison in a Radiocarbon Assay

    Science.gov (United States)

    Schoenberg, Steven A.; Benner, Ronald; Armstrong, Anthony; Sobecky, Patricia; Hodson, Robert E.

    1990-01-01

    Radiolabeled phytoplankton and macrophyte lignocelluloses were incubated at pHs 4 and 7 in water from a naturally acidic freshwater wetland (Okefenokee Swamp; ambient pH, 3.8 to 4.2), a freshwater reservoir (L-Lake; pH 6.7 to 7.2), and a marine marsh (Sapelo Island; pH ∼7.8). The data suggest that acidity is an important factor in explaining the lower decomposition rates of algae in Okefenokee Swamp water relative to L-Lake or Sapelo Island water. The decomposition of algal substrate was less sensitive to low pH (∼5 to 35% inhibition) than was the decomposition of lignocellulose (∼30 to 70% inhibition). These substrate-dependent differences were greater and more consistent in salt marsh than in L-lake incubations. In both freshwater sites, the extent to which decomposition was suppressed by acidity was greater for green algal substrate than for mixed diatom or blue-green algal (cyanobacteria) substrates. The use of different bases to adjust pH or incubation in a defined saltwater medium had no significant effect on substrate-dependent differences. Although pH differences with lignocellulose were larger in marine incubations, amendment of lakewater with marine bacteria or with calcium, known to stabilize exoenzymes in soils, did not magnify the sensitivity of decomposition to acid stress. PMID:16348097

  8. Manned submersible „JAGO“

    Directory of Open Access Journals (Sweden)

    Karen Hissmann

    2017-04-01

    Full Text Available The manned submersible „JAGO“ is a human occupied underwater vehicle (HOV designed for personal exploration and research in all types of aquatic systems and habitats. The seafloor along the continental shelf and slopes within the ocean twilight zone is JAGO’s main target area. The DNV-GL classed 2-person submersible has a maximum operating depth of 400 m. The two occupants, the pilot and one observer, are seated at 1 Atmosphere in a steel pressure hull with two large acrylic windows. The submersible’s small size and lightweight construction (3 T allows worldwide operations from on board a wide variety of vessels as well as transport in a single standard 20-foot container together with all support equipment. Typical applications include personal observation of the sea bed and water column, video and photo documentation, selective non-intrusive sampling, placement of sensors and experiments, underwater inspection, as well as location and recovery of objects

  9. Aquatic macrophytes drive sediment stoichiometry and the suspended particulate organic carbon composition of a tropical coastal lagoon Macrófitas aquáticas determinam a estequiometria do sedimento e a composição do carbono orgânico particulado em suspensão de uma lagoa costeira tropical

    Directory of Open Access Journals (Sweden)

    Cláudio Cardoso Marinho

    2010-06-01

    Full Text Available AIM: This research aimed to evaluate (1 the influence of the aquatic macrophytes Typha domingensis Pers., Eleocharis interstincta (Vahl Roem. & Schult. (emergent and Potamogeton stenostachys K. Schum. (submersed on sediment stoichiometry and (2 the contribution of these aquatic macrophytes to organic carbon composition in different compartments of a tropical coastal lagoon (Cabiúnas Lagoon, Macaé-RJ; METHODS: The concentration of carbon (C, nitrogen (N and phosphorus (P was determined in 2-cm intervals in the first 10 cm of sediment in both littoral and limnetic regions. In the littoral region, the sediment was collected in three different sites: T. domingensis, E. interstincta and P. stenostachys stands. In order to know the pathways of C in Cabiunas lagoon, the isotopic signature (δ13C of restinga terrestrial vegetation, zooplankton, phytoplankton, macrophytes, dissolved and suspended material on water were evaluated; RESULTS: The concentrations of C and N in the sediment of the E. interstincta and T. domingensis stands were significantly higher than in the sediment of the limnetic region. The concentration of phosphorus in the sediment colonized by T. domingensis was higher than in the limnetic region and in P. stenostachys stand. The highest molar C:P ratios were found in E. interstincta and P. stenostachys stands. The highest N:P ratios were also found in the littoral region. Carbon stable isotopic analysis (δ13C signatures showed that a majority of the particulate organic carbon (POC in the water column had aquatic macrophyte tissues origin; CONCLUSIONS: Emergent macrophytes strongly contribute to nutrient enrichment of the sediment of Cabiúnas lagoon. In general, macrophyte detritus alters the littoral region sediment stoichiometry and quality for decomposers, by accumulating much more C in relation to N and P when compared to limnetic region. However, macrophytes importance isn't restricted to the sediment once they have a central

  10. Aquatic macrophytes in natural and managed wetlands of Rio Grande do Sul State, Southern Brazil Macrófitas aquáticas em áreas úmidas naturais e manejadas do Rio Grande do Sul, sul do Brasil

    Directory of Open Access Journals (Sweden)

    Ana Silvia Rolon

    2010-06-01

    Full Text Available AIM: This study gathers the main results obtained from studies regarding dynamic of aquatic macrophyte community in natural and managed wetlands of Southern Brazil. We analyzed the aquatic macrophytes diversity in wetlands of Southern Brazil, the environmental factors that determine the structure of the aquatic macrophyte community in fragmented wetlands, the effects of floods on the dynamics of macrophytes, and the contributions to the rice field for the conservation of aquatic macrophytes; METHODS: The information was obtained from several researches carried in several spatial scales and different wetlands types over the last 10 years in Southern Brazil; RESULTS: The studies have reported the occurrence of approximately 250 species of aquatic macrophytes. Wetland area, habitat diversity, altitude and hydroperiod were determinant for macrophyte richness and composition in wetlands of Southern Brazil. Furthermore, flood events, long or short-term ones, are strongly associated to the structure of the aquatic macrophyte community. The rice field systems of Southern Brazil (crops and irrigation channel shelter a representative number of species of macrophyte found at natural wetlands in this region. The agricultural practices adopted over rice cultivation cycle in the rice fields have influenced the macrophyte richness and biomass. The different hydrological management practices adopted after the harvesting period (presence or lack of water surface did not influence the macrophyte richness and biomass, however it influenced the species composition; CONCLUSIONS: The increasing process of wetland degradation (e.g. fragmentation, flood control and rice field expansion presents a threat to the conservation aquatic macrophyte species.OBJETIVO: Este estudo reúne os principais resultados obtidos em trabalhos sobre a dinâmica da comunidade de macrófitas aquáticas em áreas úmidas naturais e manejadas do sul do Brasil. Nós analisamos a diversidade de

  11. Functional groups of entomofauna associated to aquatic macrophytes in Correntoso river, Rio Negro sub-region, Pantanal, Mato Grosso do Sul State, Brazil - doi: 10.4025/actascibiolsci.v34i1.7822

    Directory of Open Access Journals (Sweden)

    José Sabino

    2011-11-01

    Full Text Available This work aimed to study the structure of functional groups of entomofauna associated to aquatic macrophytes in Correntoso river, Rio Negro sub-region, Pantanal, Mato Grosso do Sul State, Brazil. Six samples were taken in different seasonal periods; ebb, dry and wet. The organisms were collected using D net (300 m mesh, sweeping five times through the roots of macrophyte banks at each sample session. Three environments were compared (open, intermediary, close using data from six collection sites, through which were analyzed absolute abundance, observed richness of families and the sampled specimens were also separated in functional groups. A total of 60 families from 12 orders of Insecta were registered, totaling 19,773 sampled insects. The largest number of families was categorized into predators functional group, with 34 families collected, followed by the collectors with 17, shredders-herbivores ten and scrapers eight.

  12. Effects of copper-oxide nanoparticles, dissolved copper and ultraviolet radiation on copper bioaccumulation, photosynthesis and oxidative stress in the aquatic macrophyte Elodea nuttallii.

    Science.gov (United States)

    Regier, Nicole; Cosio, Claudia; von Moos, Nadia; Slaveykova, Vera I

    2015-06-01

    In this study, the uptake and sub-toxic effects of CuO nanoparticles (CuO-NPs), dissolved Cu(II) alone or in combination with UV radiation on the aquatic macrophyte Elodea nuttallii were studied. Emphasis was on Cu accumulation, growth, photosynthesis and the oxidative stress related enzymes peroxidase (POD) and superoxide dismutase (SOD). The results showed stronger Cu accumulation in plants exposed to 10 mg L(-1) CuO-NPs, corresponding to 1.4-2 mg L(-1) dissolved Cu(II), than to 256 μg L(-1) Cu(II). However, the ratio between the accumulated Cu and dissolved Cu in CuO treatments was lower than in Cu(II) treatments. Additional UV exposure increased accumulation in both treatments, with the effect being stronger for Cu accumulation from CuO-NPs than for dissolved Cu(II). Photosynthetic capacity was strongly reduced by UV treatment, whereas remained unaffected by Cu(II) or CuO-NP treatments. Similarly, the increase of SOD activity was more pronounced in the UV treatments. On the other hand, POD activity enhancement was strongest in the plants exposed to CuO-NPs for 24 h. Expression of the copper transporter COPT1 as revealed by RT-qPCR was inhibited by Cu(II) and CuO-NP treatment, limiting the uptake of excess Cu into the cells. Overall, the combined exposure of E. nuttallii to UV radiation with CuO-NPs or Cu(II) has a higher impact than exposure to CuO-NPs or Cu(II) alone. The results imply that heavy pollution of natural water with CuO-NPs or dissolved Cu might have stronger effects in combination with natural UV irradiation on organisms in situ. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Checklist das macrófitas aquáticas do Pantanal, Brasil Checklist of the aquatic macrophytes of the Pantanal, Brazil

    Directory of Open Access Journals (Sweden)

    Vali Joana Pott

    1997-12-01

    Full Text Available O Pantanal, por ser alagável, é ambiente favorável ao desenvolvimento de muitas plantas aquáticas. Para atender demandas de levantamentos florísticos regionais, fez-se a listagem das macrófitas aquáticas do Pantanal, com base em coletas depositadas nos Herbários CPAP (EMBRAPA, COR (Universidade Federal de Mato Grosso do Sul, CH (Universidade Federal de Mato Grosso e K (Kew. Até o momento, foram levantadas 242 espécies, distribuídas em 106 gêneros e 54 famílias. As famílias mais numerosas são Poaceae (22 espécies, Cyperaceae(17, Leguminosae e Scrophulariaceae(14, Alismataceae e Onagraceae(13, Pontederiaceae(11, Lentibulariaceae(10, Characeae(9, emnaceae, Malvaceae e Nymphaeaceae(8. A maioria das demais famílias apresentam uma ou duas espécies cada. Quanto à forma biológica, 39% são plantas emergentes, 28% anfíbias, 11,5% flutuantes fixas, 8% flutuantes livres, 8% submersas fixas, 3,8% submersas livres e 1,7% epífítas. Os principais gêneros em número de espécies são Nymphaea, Utricularia, Echinodorus, Ludwigia, Polygonum, Aeschynomene, Cyperus, Eleocharis e Bacopa.The Pantanal, being a wetland, is a favorable environment for the development of many aquatic plants. This list of aquatic macrophytes of the Pantanal was made based on field collections, deposited at Herbarium CPAP (EMBRAPA, COR (Universidade Federal de Mato Grosso do Sul, CH (Universidade Federal de Mato Grosso and K (Kew, to support regional floristic surveys. Until present, 242 species were listed, distributed within 106 genera and 54 families. The most numerous families were Poaceae (22 species Cyperaceae(17, Leguminosae and Scrophulariaceae(14, Alismataceae and Onagraceae(13, Pontederiaceae (11, Lentibulariaceae(10, Characeae(9, Lemnaceae, Malvaceae andNymphaeaceae(8. The majority of other families has one or two species each. The life form spectrum includes 39% emergent plants, 28% amphibious, 11,5% rooted floating, 8% free floating, 8% rooted submerged

  14. Investigation of Darwin’s naturalization hypothesis in invaded macrophyte communities

    Science.gov (United States)

    Although native macrophytes are beneficial in aquatic ecosystems, invasive macrophytes can cause significant ecological and economic harm. Numerous studies have attributed invasiveness to species’ characteristics, whereas others attribute invasion to biotic and abiotic characteristics of the invaded...

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

    Science.gov (United States)

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

    2015-01-01

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

  16. Impacts of Different Water Pollution Sources on Antioxidant Defense Ability in Three Aquatic Macrophytes in Assiut Province, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed A.A. Gadallah

    2014-08-01

    Full Text Available The present study was undertaken to evaluate the impacts of surface water pollution with wastes coming from sewage effluents (Site 2, agricultural runoff (Site 4 and oils and detergents factory (Site 3 on the stability of leaf membrane (measured as injury %, hydrogen peroxide (H2O2, ascorbic acid (Asc A, lipid peroxidation, chlorophyll (Chl content, soluble sugars (SS, soluble proteins (SP and total free amino acids (TAA of Cyperus alopeucroides, Persicaria salicifolia and Echinochloa stagnina. Concentration of H2O2, MDA and TAA were higher in the three plants collected from polluted sites as compared with those of plants grown in control Nile site (Site1. The opposite was true for Asc A, SS and SP where their concentrations reduced significantly in response to water pollution. Leaf membrane was more damaged (high injury % in plants exposed to wastes from different sources than in plants growing at control site. The results of this study indicated that water pollution reduced the oxidative defense abilities in the three plants through reduction of Asc A activities, enhancement of H2O2 production and increasing MDA accumulation. In addition it impaired the metabolic activity through lowering the SS and SP contents and enhancement of TAA accumulation and increase membrane injury. The over production of hydrogen peroxide by the studied aquatic plants under water pollution could be used as an oxygen source needed to oxidize the more resistant organic and inorganic pollutants and used for pollution control and municipal and industrial wastewater treatment.

  17. Relationship of weed shiner and young-of-year bluegill and largemouth bass abundance to submersed aquatic vegetation in Navigation Pools 4, 8, and 13 of the Upper Mississippi River, 1998-2012

    Science.gov (United States)

    DeLain, Steven A.; Popp, Walter A.

    2014-01-01

    Aquatic vegetation provides food resources and shelter for many species of fish. This study found a significant relationship between increases in submersed aquatic vegetation (SAV) in four study reaches of the Upper Mississippi River (UMR) and increases in catch-per-unit-effort (CPUE) of weed shiners (Notropis texanus) and age-0 bluegills (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) when all of the study reaches were treated collectively using Long Term Resource Monitoring Program (LTRMP) vegetation and fish data for 1998–2012. The selected fishes were more abundant in study reaches with higher SAV frequencies (Pool 8 and Lower Pool 4) and less abundant in reaches with lower SAV frequencies (Pool 13 and Upper Pool 4). When each study reach was examined independently, the relationship between SAV frequency and CPUE of the three species was not significant in most cases, the primary exception being weed shiners in Lower Pool 4. Results of this study indicate that the prevalence of SAV does affect relative abundance of these vegetation-associated fish species. However, the poor annual relationship between SAV frequency and age-0 relative abundance in individual study reaches indicates that several other factors also govern age-0 abundance. The data indicate that there may be a SAV frequency threshold in backwaters above which there is not a strong relationship with abundance of these fish species. This is indicated by the high annual CPUE variability of the three selected fishes in backwaters of Pool 8 and Lower Pool 4 when SAV exceeded certain frequencies.

  18. Can an aquatic macrophyte bioaccumulate glyphosate? A watershed scale study using a non-target hydrophyte Ludwigia peploides

    Science.gov (United States)

    Perez, Debora; Okada, Elena; Menone, Mirta; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    water, rather than sediment. In this sense, L.peploides could be used as biomonitor organism to evaluate a glyphosate levels in the freshwater aquatic ecosystems

  19. Submersion and acute respiratory failure

    Directory of Open Access Journals (Sweden)

    Yu-Jang Su

    2014-01-01

    Conclusions: Submersion patients who are hypothermic on arrival of emergency department (ED are risky to respiratory failure and older, more hypothermic, longer hospital stay in suicidal submersion patients.

  20. Eficiência de fluridone no controle de plantas aquáticas submersas no reservatório de Jupiá Fluridone efficacy for control of submersed aquatic weeds in the Jupiá reservoir

    Directory of Open Access Journals (Sweden)

    D.A.S. Marcondes

    2003-01-01

    Full Text Available O objetivo deste estudo foi avaliar a eficiência do herbicida fluridone no controle de plantas aquáticas submersas (Egeria densa, Egeria najas e Ceratophyllum demersum que ocorrem no reservatório da Usina Hidrelétrica Eng. Souza Dias (Jupiá, região noroeste do Estado de São Paulo. A pesquisa, que consistiu de aplicações de fluridone, foi conduzida em lagoas marginais do rio Tietê, denominadas Flórida e Barrenta. As lagoas foram divididas em faixas, cada uma delas representando um tratamento. As faixas das lagoas receberam uma aplicação inicial de fluridone, procurando-se atingir a concentração de 20 ppb. As aplicações subseqüentes foram dimensionadas para recompor e/ou manter esta concentração, sendo realizadas sempre com o auxílio de uma barra de aplicação munida de três mangueiras, com pontas injetoras submersas na água, em três profundidades (0,2, 0,6 e 1,2 m. O volume de aplicação foi mantido próximo a 54 l ha-1 de calda. Foram feitas avaliações visuais dos sintomas de fitointoxicação nas três espécies estudadas, assim como avaliação da biomassa. Nas condições da pesquisa, o fluridone controlou as macrófitas submersas Egeria najas e Egeria densa; quando cessou o efeito do fluridone, aconteceu a reinfestação de Egeria densa e Egeria najas; e não houve controle de Ceratophyllum demersum nem das espécies não-alvo, como Salvinia auriculata, Ipomoea spp., Merremia sp., Typha latifolia e Cyperus spp.The objective of this study was to evaluate the efficacy of the herbicide fluridone on the control of submersed aquatic weeds (Egeria densa Planch., Egeria najas Planch. and Ceratophyllum demersum, the major aquatic weeds in the reservoir of Engº Souza Dias (Jupiá Hydroelecric Power Plant, Itapura, São Paulo. The experiment, consisted of fluridone applications and was carried out in bays of the Tietê River, called Flórida and Barrenta. The lakes were divided into zones, each considered a treatment. All

  1. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

    Binzer, T.; Sand-Jensen, K.; Middelboe, A. L.

    2006-01-01

    We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of photosynt......We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition...... fourfold from communities with a very uneven to a more even light distribution. Photosynthetic characteristics of communities are strongly influenced by plant density, absorption, and distribution of light and cannot be interpreted from the photosynthetic behavior of phytoelements. Thus, many examples...

  2. Checklist of the Aquatic Macrophytes

    African Journals Online (AJOL)

    Mangrove Area of Lagos, Nigeria. 103. A.O. Olorunfemi, K.S. Salahudeen and. Ground Water Quality in Ejigbo Town and Environs,. T.A. Adesiyan. Southwestern Nigeria. 111. Govardhan Singh, R.S; Ogunsina, B.S.. Protein Extractability from Defatted Moringa Oleifera Lam. and Radha, C. Seeds Flour. 121. A. M. A. Sakpere.

  3. Trends of superoxide dismutase and soluble protein of aquatic plants in lakes of different trophic levels in the middle and lower reaches of the Yangtze River, China.

    Science.gov (United States)

    Wu, Ai-Ping; Cao, Te; Wu, Shi-Kai; Ni, Le-Yi; Xie, Ping

    2009-04-01

    A limnological study was carried out to determine the responses of superoxide dismutase (SOD) activities and soluble protein (SP) contents of 11 common aquatic plants to eutrophication stress. Field investigation in 12 lakes in the middle and lower reaches of the Yangtze River was carried out from March to September 2004. Our results indicated that non-submersed (emergent and floating-leafed) plants and submersed plants showed different responses to eutrophication stress. Both SOD activities of the non-submersed and submersed plants were negatively correlated with their SP contents (P plants were significantly correlated with all nitrogen variables in the water (P plants were only significantly correlated with carbon variables as well as ammonium and Secchi depth (SD) in water (P plants were decreased with decline of SD in water (P plants were mainly caused by light limitation, this showed a coincidence with the decline of macrophytes in eutrophic lakes, which might imply that the antioxidant system of the submersed plants were impaired under eutrophication stress.

  4. Macrophyte diversity in polluted and non-polluted wetlands in ...

    African Journals Online (AJOL)

    The macrophyte species identified were both terrestrial, aquatic and wetland species, some of which have already been tested in other countries in constructed wetlands for wastewater treatment. The number of macrophyte species recorded in the polluted wetlands was low compared with that of the wetlands in the rural ...

  5. Indirect facilitation promotes macrophyte survival and growth in freshwater ecosystems threatened by eutrophication

    OpenAIRE

    Le Bagousse-Pinguet, Yoann; Liancourt, Pierre; Gross, Nicolas; Straile, Dietmar

    2012-01-01

    1. Eutrophication is a major threat for freshwater ecosystems. Submerged aquatic plants (macrophytes) can maintain clear water conditions in eutrophic lakes by competing with phytoplankton for light and nutrients. The interactions between macrophytes and phytoplankton may lead to indirect facilitation among plants and the maintenance of high macrophyte diversities in eutrophicconditions. Nonetheless, the role of indirect facilitation in promoting macrophyte-dominated clear water states under ...

  6. Eficiência de fluridone no controle de plantas aquáticas submersas e efeitos sobre algumas características ambientais Fluridone efficacy in controling submersed aquatic weeds and its effects on some environmental characteristics

    Directory of Open Access Journals (Sweden)

    D.A.S. Marcondes

    2002-01-01

    Full Text Available O objetivo deste estudo foi avaliar a eficiência do herbicida fluridone no controle de plantas aquáticas submersas (Egeria densa, Egeria najas e Ceratophyllum demersum, assim como seus efeitos sobre algumas características ambientais. A pesquisa foi conduzida no reservatório da Usina Hidrelétrica Eng. Souza Dias (Jupiá, região noroeste do Estado de São Paulo, em uma reentrância denominada lagoa Vírgula. A lagoa foi dividida em nove faixas e seis delas receberam uma aplicação inicial de fluridone para se obter uma concentração de 20 ppb. As aplicações subseqüentes foram dimensionadas para recompor esta concentração. Para o estudo do carreamento do herbicida pelo fluxo de água, foi efetuado o monitoramento das suas concentrações nas nove faixas da lagoa (com e sem aplicação e em áreas a jusante e a montante. Foram analisados os efeitos do fluridone sobre características ambientais como: turbidez, temperatura da água, condutividade elétrica, concentração de oxigênio, pH e resíduos de fluridone. A eficácia do controle foi avaliada visualmente (pelos sintomas de fitointoxicação nas três espécies estudadas e pela amostragem de biomassa. Observou-se que o fluridone controlou de forma satisfatória E. najas e E. densa. Quando cessou o efeito do fluridone, aconteceu a reinfestação de E. densa e E. najas. Não houve controle de C. demersum. O fluridone não produziu efeitos adversos sobre as características de qualidade ambiental estudadas.This study aimed to evaluate the efficacy of the herbicide fluridone to control submersed aquatic weeds (Egeria densa, Egeria najas and Ceratophyllum demersum, as well as its effects on some environmental characteristics. The research was carried out in the reservoir of Eng. Souza Dias (Jupiá Hydro-elecric plant power, Station in northwestern São Paulo, Brazil, in Lagoa Vírgula bay. The bay was divided in nine zones and six of them received an initial application of fluridone

  7. 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.

  8. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; Nes, van E.H.; Donk, van E.

    2007-01-01

    Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversial

  9. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; van Nes, E.H.; Van Donk, E.

    2007-01-01

    Abstract Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still

  10. Spectroradiometry Helping Macrophytes Image Detection

    Science.gov (United States)

    Bitencourt, Marisa D.; Aparicio, Cristina; Malthus, T. J.; Pompeo, Marcelo L. M.

    2009-11-01

    Infestation by aquatic macrophytes normally follows eutrophication processes, which is an undesirable outcome. Therefore, the ability to identify macrophytes could improve management processes of water bodies. However, there is a lack of basic research related to the acquisition of spectral signatures of such species, which makes it difficult to use orbital multispectral images to identify infestation. We therefore carried out laboratory experiments on some of the important infesting species. The spectral signatures of ten individuals, of twelve species, were measured using spectroradiometry. Absolute reflectance was used to predict the orbital reflectance of several satellites and to calculate Red Edge Position (REP), which can also be used to spectrally separate species. Results: a) NIR presented the best separation among the other bands; b) the spectral band was statistically significant; and c) REP had an excellent separation.

  11. Herbivory on freshwater and marine macrophytes

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Wood, Kevin A.; Pagès, Jordi F.; Veen, G.F.; Christianen, Marjolijn J.A.; Santamaría, Luis; Nolet, Bart A.; Hilt, Sabine

    2016-01-01

    Until the 1990s, herbivory on aquatic vascular plants was considered to be of minor importance, and the predominant view was that freshwater and marine macrophytes did not take part in the food web: their primary fate was the detritivorous pathway. In the last 25 years, a substantial body of

  12. Organochlorine pesticides sequestered in the aquatic macrophyte Schoenoplectus californicus (C.A. Meyer) Soják from a shallow lake in Argentina.

    Science.gov (United States)

    Miglioranza, Karina S B; de Moreno, Julia E A; Moreno, Víctor J

    2004-04-01

    This study was conducted in Los Padres Lake from Argentina in order to assess the ability of Schoenoplectus californicus to bioconcentrate organochlorine pesticides (OCPs). Bulrush tissues, superficial and near root sediments were collected from the input and the output creek areas. OCP analyses were carried out by GC-ECD. Samples from the input creek area showed the higher OCP levels as a result of contaminants washed down from upstream agricultural fields. Bulrush roots accumulated the highest concentrations of pollutants (30.2-45.7ngg(-1) dry weight). DDTs and chlordanes predominated in sediments and roots besides endosulfan sulfate. The sediments constitute the main source for these OCPs partitioning to bulrush. Stems mainly exposed to water column accumulated preferentially the less hydrophobic pesticides, such as HCHs and endosulfans. We have confirmed the important role of S. californicus in the contaminant removal from sediments. Therefore, this macrophyte can be used as a tool for field studies of OCP pollution monitoring and remediation.

  13. Fatores ecológicos associados à colonização e ao desenvolvimento de macrófitas aquáticas e desafios de manejo Ecological factors associated to aquatic macrophyte colonization and growth and management challenges

    Directory of Open Access Journals (Sweden)

    S.M. Thomaz

    2002-01-01

    Full Text Available As macrófitas constituem-se em uma importante assembléia de ecossistemas aquáticos continentais, mas seu crescimento excessivo pode provocar danos aos usos múltiplos de alguns ambientes. Durante o processo de sucessão ecológica, a maioria dos ecossistemas aquáticos é colonizada, em diferentes graus, pela vegetação aquática. No entanto, explosões populacionais são usualmente decorrentes de ações antrópicas, como introduções de espécies exóticas e alterações de habitats. O conhecimento da ecologia e biologia das espécies de macrófitas que colonizam ecossistemas tropicais ainda é escasso. Entretanto, esse conhecimento é fundamental para a predição do desenvolvimento da vegetação aquática e para subsidiar as medidas de manejo, quando estas forem necessárias. Os métodos de controle e manejo são eficazes em pequenos ambientes e sua aplicação pode ser acompanhada por uma série de impactos ecológicos, nem sempre avaliados apropriadamente. O desenvolvimento de métodos com reduzidos impactos ambientais e que sejam eficientes em grandes ecossistemas é um desafio. Deve-se ainda considerar que, embora em algumas situações o manejo seja necessário no sentido de reduzir uma parcela das populações de macrófitas, em outras ele deveria ser utilizado para estimular a colonização e o incremento desta vegetação.The aquatic macrophytes have been considered an important community in freshwater ecosystems. However, their excessive colonization and growth usually cause serious impacts on multiple use of these ecosystems. Most aquatic environments are colonized at different degrees by aquatic plants in some phase of ecological succession. Nevertheless, massive growth is usually associated with anthropogenic actions such as introduction of alien species and habitats of alterations. Knowledge about ecology and biology of the species that colonize tropical ecosystems is still scarce. This knowledge is fundamental to predict

  14. Avaliação da degradação de macrófitas aquáticas descartadas em ambiente protegido Assessment of the degradation of aquatic macrophytes discarded into a protected environment

    Directory of Open Access Journals (Sweden)

    V.R.S. Cezar

    2005-06-01

    Full Text Available Com o intuito de buscar informações sobre a degradação de macrófitas aquáticas descartadas em pilhas, após ações do controle mecânico, foi conduzido um experimento no Departamento de Recursos Naturais - Ciências Ambientais, UNESP, campus de Botucatu-SP. Para atender o objetivo proposto, foram montadas pilhas com volume de 2,25 m³, compostas, principalmente, por três espécies de macrófitas, retiradas do reservatório da UHE Americana/SP. Foram coletadas amostras na montagem das pilhas, aos 15, 30, 60 e 90 dias, para o acompanhamento da temperatura da pilha e do pH do material orgânico durante o processo, além de uma análise química do composto ao final dos 90 dias. Os tratamentos foram: T1 - somente plantas aquáticas e revolvimento da pilha a cada sete dias; T2 - somente plantas aquáticas e revolvimento a cada quatro dias; T3 - plantas aquáticas + permagel, com revolvimento a cada sete dias; e T4 - plantas aquáticas + permagel e revolvimento a cada quatro dias. Utilizou-se o delineamento estatístico inteiramente casualizado, sendo a análise estatística realizada para coleta aos 90 dias, empregando o programa SISVAR. Concluiu-se que os resultados de macro e micronutrientes, temperatura, umidade, pH, relação C/N e redução do volume das pilhas foram semelhantes aos observados quando se procedeu ao descarte em pilhas com volume de 4,5 m³ sobre o solo.An experiment was carried out at the Department of Natural Resources - Environmental Science, UNESP, Botucatu-SP to evaluate the degradation of aquatic macrophytes discarded in stacks, after mechanical control measures. Stacks of 2.25 m³ volume were set up, composed of three species of macrophytes collected from the Americana UHE reservoir in Sao Paulo. Stack samples were collected at 15, 30, 60 and 90 days, for temperature monitoring and organic material pH assessment during the process, besides compound chemical analysis at day 90. The treatments were: T1-only aquatic

  15. Limnological variables and nutritional content of submerged aquatic macrophytes in a tropical lagoon Variáveis limnológicas e conteúdo nutricional de macrófitas aquáticas submersas em uma lagoa tropical

    Directory of Open Access Journals (Sweden)

    Bruno dos Santos Esteves

    2010-06-01

    Full Text Available AIM: The aim of this study was to evaluate elemental composition (C, N and P and carbohydrate and lipids content of aquatic macrophytes Egeria densa, Ceratophyllum demersum and Najas marina found in a lagoon of Norte Fluminense and relate these data to limnological parameters measured in the same period; METHODS: The samples were obtained from 10 sites throughout the lagoon in July/2001 (dry season and January/2002 (rainy season with determinations limnological parameters and quantification of nutrient content and biochemical composition of the aquatic macrophytes; RESULTS: High values of electrical conductivity and alkalinity explain the spatial distribution of the studied macrophytes; and the pH values (OBJETIVO: O objetivo deste estudo foi avaliar a composição elementar (C, N e P e conteúdo de carboidratos e lipídeos das macrófitas aquáticas Egeria densa, Ceratophyllum demersum e Najas marina encontradas em uma lagoa do Norte Fluminense, e relacionar esses dados a parâmetros limnológicos medidos em igual período; MÉTODOS: As amostras foram obtidas em julho/2001 (período seco e janeiro/2002 (período chuvoso, em 10 pontos ao longo da lagoa do Campelo com determinações de parâmetros limnológicos e quantificação de componentes nutricionais e bioquímicos das macrófitas aquáticas; RESULTADOS: Elevados valores de condutividade elétrica e alcalinidade explicam a distribuição espacial das macrófitas estudadas, e os valores de pH (<9,0, supersaturação de O2 e subsaturação de CO2 sugerem uma elevada produção primária, tanto fitoplanctônica quanto de macrófitas submersas. Para os nutrientes avaliados nas macrófitas aquáticas, variações sazonais significativas foram observadas no conteúdo de fósforo total (p < 0,05, de nitrogênio total e carbono total, entretanto, sem qualquer padrão definido entre períodos sazonais e macrófitas. Observou-se tendência às maiores concentrações de P nos tecidos das macr

  16. Aquatic Plants and their Control.

    Science.gov (United States)

    Michigan State Dept. of Natural Resources, Lansing.

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

  17. Macrófitas aquáticas de um lago marginal ao rio Embu-mirim, São Paulo, Brasil Aquatic macrophytes from a marginal pond at Embu-mirim river, S.Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Zuleika Beyruth

    1992-08-01

    Full Text Available Durante os anos de 1984/1985 obtiveram-se amostras sazonais para determinação de parâmetros físicos, químicos e biológicos de um lago marginal ao rio Embu-mirim, em Itapecerica da Serra, na bacia do reservatório de Guarapiranga (São Paulo, Brasil. Além de discutir os resultados obtidos quanto à flora de macrófitas aquáticas e suas relações com os outros parâmetros ambientais, são também analisados os efeitos da variação sazonal. As espécies encontradas estão presentes em diversos corpos d'água marginais, bem como ao longo do rio Embu-mirim, permitindo avaliar seu comportamento em corpos d'água semelhantes, da mesma bacia. A macrófita predominante foi Eichhornia crassipes (Mart. Solms. Os resultados obtidos demostram a tendência de uma eutrofização acelerada e o risco de macrófitas potencialmente problemáticas, como E. crassipes e Salvinia auriculata, formarem camalotes de altas densidades, que podem chegar ao reservatório de Guarapiranga, através do rio Embu-mirim, causando problemas aos diversos usos da água.In the years 1984/1985, limnological surveys were carried out at a marginal pond of the Embu-mirim river belonging to the hydrographic basin of Guarapiranga Reservoir (S. Paulo, Brazil, in order to obtain data for the determination of physical, chemical and biological parameters. Results obtained from the study of the aquatic macrophytes and their relationships with other environmental parameters are analised. Eichhornia crassipes (Mart. Solms, the dominant macrophyte, was observed in several water bodies of that basin, including the river it self, thus favoring an evaluation of its behavior in similar water bodies of the basin.

  18. Influence of water level fluctuation on the mortality and aboveground biomass of the aquatic macrophyte Eleocharis interstincta (VAHL roemer et schults

    Directory of Open Access Journals (Sweden)

    Santos Anderson Medeiros dos

    2004-01-01

    Full Text Available The goal of this study was to study the biometric alterations of Eleocharis interstincta in response to water level fluctuations in Cabiúnas Lagoon, located on the northern coast of the state of Rio de Janeiro, in the municipality of Macaé. Three quadrats of 0.0625 m² were harvested every two weeks from June/1997 to June/1998; samples were separated into stems, dead stems (detritus and rhizome; lenghted, dried and weighted. The water level fluctuated seasonally in the macrophyte stand with two periods of drawdown. The first period occurred naturally at the end of winter and beginning of spring, when rainfall in the area was normally lowest. The second period of drawdown was the result of an artificial breaching of the sandbar that isolate the lagoon from the sea. The breach was made in the summer, at the time of highest rainfall, when the water level in the lagoon reached the maximum value recorded during the study (1.35 m. There was a strongly positive correlation of the water level with stems mean height and aboveground biomass, indicating that water level played an important role in the determination of these parameters. There was a significant difference between stem height (ANOVA; p < 0.001 and biomass (ANOVA; p < 0.001 in each sampling period, ranging from 143.9 cm and 338.8 g dry wt.m-2, before the sandbar opening, to 16.3 cm and 20.2 g dry wt.m-2 respectively after the sandbar breaching. The drastic variation of the water level, leading mass mortality of the stems, together with the lowest mean biomass/stem (0.057 g dry wt.individual-1, recorded after the sandbar breaching, did not represent a strong disturbance for E. interstincta, since the resilience time estimated for this population was about 30 days.

  19. Water level fluctuations in a tropical reservoir: the impact of sediment drying, aquatic macrophyte dieback, and oxygen availability on phosphorus mobilization.

    Science.gov (United States)

    Keitel, Jonas; Zak, Dominik; Hupfer, Michael

    2016-04-01

    Reservoirs in semi-arid areas are subject to water level fluctuations (WLF) that alter biogeochemical processes in the sediment. We hypothesized that wet-dry cycles may cause internal eutrophication in such systems when they affect densely vegetated shallow areas. To assess the impact of WLF on phosphorus (P) mobilization and benthic P cycling of iron-rich sediments, we tested the effects of (i) sediment drying and rewetting, (ii) the impact of organic matter availability in the form of dried Brazilian Waterweed (Egeria densa), and (iii) alternating redox conditions in the surface water. In principle, drying led to increased P release after rewetting both in plant-free and in plant-amended sediments. Highest P mobilization was recorded in plant amendments under oxygen-free conditions. After re-establishment of aerobic conditions, P concentrations in surface water decreased substantially owing to P retention by sediments. In desiccated and re-inundated sediments, P retention decreased by up to 30% compared to constantly inundated sediments. We showed that WLF may trigger biochemical interactions conducive to anaerobic P release. Thereby, E. densa showed high P release and even P uptake that was redox-controlled and superimposed sedimentary P cycling. Macrophytes play an important role in the uptake of P from the water but may be also a significant source of P in wet-dry cycles. We estimated a potential for the abrupt release of soluble reactive phosphorus (SRP) by E. densa of 0.09-0.13 g SRP per m(2) after each wet-dry cycle. Released SRP may exceed critical P limits for eutrophication, provoking usage restrictions. Our results have implications for management of reservoirs in semi-arid regions affected by WLF.

  20. 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

  1. Analysis of Satellite and Airborne Imagery for Detection of Water Hyacinth and Other Invasive Floating Macrophytes and Tracking of Aquatic Weed Control Efficacy

    Science.gov (United States)

    Potter, Christopher

    2016-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed an 80 percent overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  2. Uptake of Cadmium, Copper, Lead, and Zinc from Sediments by an Aquatic Macrophyte and by Terrestrial Arthropods in a Freshwater Wetland Ecosystem.

    Science.gov (United States)

    Kim, Heung-Tae; Kim, Jae Geun

    2016-08-01

    The objective of this study was to investigate trace-metal [cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn)] biotransference and biomagnification in terrestrial biota at different trophic levels (primary producer-top predator) of a wetland ecosystem. We investigated whether metal concentrations in the sediment are reflected in terrestrial arthropods and aquatic plants. We sampled the floating-leaved plant Trapa japonica; its species-specific primary consumer, the leaf beetle Galerucella nipponensis; and two predatory arthropods (the water strider Gerris sp. and the wolf spider Arctosa sp.) from three wetlands with different sedimentary metal concentrations. The δ(13)C and δ(15)N signatures in the trophic link between the plants and the leaf beetles supported the specificity of their feeding relationship. The stable isotope signatures indicate that the leaf beetle could be an important link in the trophic transfer of the metals. Transference factors (TFs) were Cu and Zn had TF >1 for all biota, and the concentrations were positively correlated with the trophic levels. Thus, there may be Cu and Zn biomagnification in the arthropods. We noted TF 1 among the arthropods. Therefore, Cd is probably not biomagnified between T. japonica and G. nipponensis, but it might be biomagnified in the arthropods. The metal burden in terrestrial arthropods may also be influenced by uptake from the sediment by aquatic plants.

  3. Flow Velocity and Morphology of a Submerged Patch of the Aquatic Species

    NARCIS (Netherlands)

    Cornacchia, L.; Licci, S.; van de Koppel, J.; van der Wal, D.; Wharton, G.; Puijalon, S.; Bouma, T.J.

    2016-01-01

    The interaction between macrophytes and hydrodynamic conditions is animportant feature in many aquatic ecosystems. Submerged macrophytes can formmonospecific patches that interact with the flow and alter current velocity; withinthe same vegetation patch, plants are exposed to different levels of

  4. Potencial alelopático de macrófitas aquáticas de um estuário cego Allelopathic potential of aquatic macrophytes from a blind estuary

    Directory of Open Access Journals (Sweden)

    Leandro Kenji Takao

    2011-06-01

    Full Text Available Macrófitas aquáticas representam uma das comunidades mais produtivas e através de sua atividade metabólica são capazes de produzir grandes interferências no ambiente. As interações alelopáticas são aparentemente aumentadas sob condições de estresse biótico e abiótico e podem existir em estuários devido à competição, variações de salinidade e outros fatores. O objetivo desse trabalho foi avaliar as propriedades alelopáticas de extratos aquosos foliares de 25 espécies de macrófitas aquáticas de um estuário cego. Testamos os efeitos dos extratos foliares em quatro concentrações sobre a germinação de alface. Ordenamos e comparamos as espécies doadoras de acordo com a dose reposta sobre a variedade de tratamentos a partir de valores únicos de índices alelopáticos. Onze das 25 espécies diminuíram a porcentagem de germinação, todas diminuíram a velocidade de germinação e aumentaram a entropia informacional de germinação das sementes da espécie alvo em pelo menos uma das concentrações testadas. Crinum americanum L., Sagittaria montevidensis Cham. & Schl. e Ipomoea cairica (L Sweet apresentaram os maiores valores de índice alelopático. Em geral, as menores porcentagens de germinação coincidiram com as menores velocidades e maiores entropias informacionais de germinação das sementes de alface, mostrando um conjunto de alterações ocorrendo simultaneamente com o aumento da concentração dos extratos.Aquatic macrophytes represent one of the most productive communities and through metabolic activity are capable of producing great interference in the environment. Allelopathic interactions are apparently increased under biotic and abiotic stress and may exist in estuaries due to competition, salinity variation and other factors. The aim of this study was to evaluate the allelopathic properties of leaf extracts of 25 aquatic macrophyte species from a blind estuary. We tested leaf extract effects in four

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

    OpenAIRE

    Xing W.; Shi Q.; Liu H.; Liu G.

    2016-01-01

    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 ...

  6. Can an aquatic macrophyte bioaccumulate glyphosate? Development of a new method of glyphosate extraction in Ludwigia peploides and watershed scale validation.

    Science.gov (United States)

    Pérez, Débora Jesabel; Okada, Elena; Menone, Mirta Luján; Costa, José Luis

    2017-10-01

    Glyphosate is intensively used in agricultural fields and it is frequently detected in non-target wetland ecosystems. The floating hydrophyte Ludwigia peploides is widely distributed in American streams and it is an abundant species. Therefore, our objectives were (1) to establish and validate an extraction and quantification methodology for glyphosate in L. peploides and (2) to evaluate the role of this species as a potential glyphosate biomonitor in an agricultural watershed. We developed a new method of glyphosate extraction from leaves of L. peploides. The method recovery was 117± 20% and the matrix effect 20%. To validate the method using environmental samples, plants of L. peploides were collected in March 2016 from eight monitoring sites of El Crespo stream. Surface water and sediment samples were collected at the same time to measure glyphosate and to calculate bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs). Glyphosate was detected in 94.11% in leaves, the concentrations ranging between 4 and 108 μg/kg. Glyphosate was detected in surface water and sediments at 75% and 100% of the samples, at concentrations that varied between 0 and 1.7 μg/L and 5-10.50 μg/kg dry weight, respectively. The mean BCFs and BSAFs were 88.10 L/Kg and 7.61, respectively. These results indicate that L. peploides bioaccumulates glyphosate mainly bioavailable in the surface water. In this sense, L. peploides could be used as a biomonitor organism to evaluate glyphosate levels in freshwater aquatic ecosystems because, in addition to its capacity to bioconcentrate glyphosate, it is easy to sample and it has a restricted mobility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Ammonia-oxidizing Bacteria and Archaea in the Rhizosphere of Freshwater Macrophytes

    DEFF Research Database (Denmark)

    Herrmann, Martina; Schramm, Andreas

    2007-01-01

    AMMONIA-OXIDIZING ARCHAEA AND BACTERIA IN THE RHIZOSPHERE OF FRESHWATER MACROPHYTES Martina Herrmann and Andreas Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia dortmanna release oxygen from...... their roots and thereby stimulate nitrification and coupled nitrification-denitrification in their rhizosphere. However, oxygen release and inorganic nitrogen concentrations differ markedly between macrophyte species. We therefore propose (i) that the rhizosphere of freshwater macrophytes harbours a species......-specific microbial community distinct from that of unvegetated sediment and (ii) that aquatic macrophytes have an impact on abundance and activity of nitrifying and denitrifying bacteria in freshwater sediment. The goal of this study was to test these hypotheses for the key functional group for coupled nitrification...

  8. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    Directory of Open Access Journals (Sweden)

    Jessica E M van der Wal

    Full Text Available Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  9. Herbivory on freshwater and marine macrophytes : A review and perspective

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Wood, Kevin A.; Pages, Jordi F.; Veen, G. F. (Ciska); Christianen, Marjolijn J. A.; Santamaria, Luis; Nolet, Bart A.; Hilt, Sabine

    2016-01-01

    Until the 1990s, herbivory on aquatic vascular plants was considered to be of minor importance, and the predominant view was that freshwater and marine macrophytes did not take part in the food web: their primary fate was the detritivorous pathway. In the last 25 years, a substantial body of

  10. Herbivory on freshwater and marine macrophytes: a review and perspective

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Wood, Kevin A.; Pagès, Jordi F.; Veen, G.F.; Christianen, Marjolijn J.A.; Santamaría, Luis; Nolet, Bart A.; Hilt, Sabine

    2016-01-01

    Until the 1990s, herbivory on aquatic vascular plants was considered to be of minor importance, and the predominant view was that freshwater and marine macrophytes did not take part in the food web: their primary fate was the detritivorous pathway. In the last 25 years, a substantial body of

  11. The association between invertebrates and macrophytes in a ...

    African Journals Online (AJOL)

    The invertebrate fauna associated with aquatic macrophytes in the littoral of Lake Kariba was studied over a three-month period in 2002. Animals from seven classes — Hirudinea, Oligochaeta, Turbellaria, Insecta, Crustacea, Bivalvia and Gastropoda — were collected. Two hirudineans, Placobdella sp. and Haemopsis sp., ...

  12. Macrophytes in estuarine gradients : Flow through flexible vegetation

    NARCIS (Netherlands)

    Dijkstra, J.T.

    2012-01-01

    Aquatic plants –or macrophytes- are an important part of coastal, estuarine and freshwater ecosystems worldwide, both from an ecological and an engineering viewpoint. Their meadows provide a wide range of ecosystem services: forming a physical protection of the shoreline, enhancing water quality and

  13. Chemical warfare in freshwater. Allelpathic effects of macrophytes on phytoplankton

    NARCIS (Netherlands)

    Mulderij, G.

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field

  14. Vulnerabilities of macrophytes distribution due to climate change

    Science.gov (United States)

    Hossain, Kaizar; Yadav, Sarita; Quaik, Shlrene; Pant, Gaurav; Maruthi, A. Y.; Ismail, Norli

    2017-08-01

    The rise in the earth's surface and water temperature is part of the effect of climatic change that has been observed for the last decade. The rates of climate change are unprecedented, and biological responses to these changes have also been prominent in all levels of species, communities and ecosystems. Aquatic-terrestrial ecotones are vulnerable to climate change, and degradation of the emergent aquatic macrophyte zone would have contributed severe ecological consequences for freshwater, wetland and terrestrial ecosystems. Most researches on climate change effects on biodiversity are contemplating on the terrestrial realm, and considerable changes in terrestrial biodiversity and species' distributions have been detected in response to climate change. This is unfortunate, given the importance of aquatic systems for providing ecosystem goods and services. Thus, if researchers were able to identify early-warning indicators of anthropogenic environmental changes on aquatic species, communities and ecosystems, it would certainly help to manage and conserve these systems in a sustainable way. One of such early-warning indicators concerns the expansion of emergent macrophytes in aquatic-terrestrial ecotones. Hence, this review highlights the impact of climatic changes towards aquatic macrophytes and their possible environmental implications.

  15. Regulation and role of epiphytic nitrification and denitrification in macrophyte-dominated systems

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Peder G.

    2000-02-01

    This thesis examines mechanisms regulating bacterial nitrification and denitrification in attached microbial communities on surfaces of aquatic macrophytes. It also evaluates the role of epiphytic nitrification and denitrification for the nitrogen turnover in macrophyte-dominated nutrient-rich freshwater. Epiphytic nitrification is promoted in light and epiphytic denitrification occurs mainly in dark, because the metabolic activity of the aquatic macrophyte and its epiphytes induce in light high and in dark low oxygen concentrations in epiphytic communities. Epiphytic nitrification and denitrification are also affected by the physical and chemical characteristics of the aquatic macrophyte. The spatial distribution of nitrification in emergent macrophyte wetlands is related to the species composition of the emergent vegetation, possibly because of a macrophyte species-related release of organic nitrification inhibitors. Contrasting to nitrifying bacteria, which are lithotrophic, denitrifying bacteria use organic substances as an energy source and are therefore stimulated by the release of organic matter from aquatic macrophytes. Epiphytic communities support more denitrification in nutrient-rich than in nutrient-poor environments. In lakes and ponds, epiphytic denitrification is higher at sheltered locations than at locations exposed to wind-induced water movements or currents. In flowing water, epiphytic denitrification occurs mainly at low oxygen concentrations in the surrounding water. However, because aquatic macrophytes impede water flow and induce low oxygen concentrations in dark, epiphytic denitrification can be present within dense vegetation despite of high oxygen concentrations in the surrounding water. Epiphytic nitrification is almost unaffected by flow conditions, and can occur both in light and in dark. In shallow-water systems such as treatment wetlands, aquatic macrophytes often provide most of the accessible surface area for attached nitrifying and

  16. Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

    Directory of Open Access Journals (Sweden)

    William R Brogan

    Full Text Available Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades. However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern

  17. Riemannian submersions and related topics

    CERN Document Server

    Falcitelli, Maria; Pastore, Anna Maria

    2004-01-01

    This book provides the first-ever systematic introduction to thetheory of Riemannian submersions, which was initiated by BarrettO''Neill and Alfred Gray less than four decades ago. The authorsfocus their attention on classification theorems when the total spaceand the fibres have nice geometric properties.

  18. [Effects of light on submerged macrophytes in eutrophic water: research progress].

    Science.gov (United States)

    Li-Sha, Zou; Ze-Yu, Nie; Xiao-Yan, Yao; Ji-Yan, Shi

    2013-07-01

    The restoration of submerged macrophytes is the key to remediate eutrophic water and maintain the health of aquatic ecosystem, while light is the main limiting factor. This paper summarized the factors affecting the light extinction in water and the mechanisms of light intensity affecting the physiology of submerged macrophytes, with the focuses on the metabolic mechanisms of carbon, nitrogen, and phosphorus, the responses of antioxidant enzyme system, and the feedbacks of pigment composition and concentration in the common submerged macrophytes under low light stress. Several engineering techniques applied in the ecological restoration of submerged macrophytes were presented, and the framework of the restoration of submerged macrophytes in eutrophic water was proposed. Some problems in current research and several suggestions on future research were addressed, which could help the related research and engineering practices.

  19. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 2. First Year Poststocking Results. Volume VII. A Model for Evaluation of the Response of the Lake Conway, Florida, Ecosystem to Introduction of the White Amur.

    Science.gov (United States)

    1981-11-01

    mentation in submersed macrophyte beds provides detritus for coloniza- tion by microbes and consumption by benthic invertebrates. Thus, both benthic and...gyrinus Zooplankton, benthic invertebrates ( tadpole madtom) Heterandria formosa Benthic invertebrates, zooplankton, (least killifish) filamentous algae

  20. Estudo comparativo da dieta, hábitos alimentares e morfologia trófica de duas espécies simpátricas, de peixes de pequeno porte, associados à macrófitas aquáticas = Comparative study about diet, feeding habits and trophic morphology of two sympatric species of small fishes in association with aquatic macrophytes

    Directory of Open Access Journals (Sweden)

    Norma Segatti Hahn

    2006-10-01

    Full Text Available Nesse estudo foram avaliados aspectos da dieta e morfologia trófica de duas espécies simpátricas, uma de Cheirodontinae e uma de Aphyocharacinae, associadas a macrofitas aquáticas, em nove lagoas isoladas da planície de inundação do alto rio Paraná, Brasil, no ano de 2001. A análise da dieta mostrou que Aphyocharax anisitsi consumiupredominantemente microcrustáceos e Serrapinnus notomelas predominantemente algas. A morfologia do trato alimentar, incluindo boca, dentes, rastros branquiais e estômago, apresentou, aparentemente, o mesmo padrão para as duas espécies. Entretanto, os dentes são mais robustos em S. notomelas. Houve interação significativa entre o comprimento padrão (F2,215 = 74,89; pIn this study we analyzed the diet and trophic morphology of two species, one of Cheirodontinae and one of Aphyocharacinae, associated with aquatic macrophytes in nine isolated lagoons of the Paraná river floodplain, Brazil, during 2001. Diet showed that Aphyocharax anisitsi feed mainly on microcrustaceans and Serrapinnus notomelas feed mainly on algae. Trophic morphology, including mouth, tooth, gill rakers and stomach showed apparently the same pattern for the two species. However, teeth are the biggest and the hardest in S. notomelas. Regarding intestine length there was significant interaction between standard length (F2.215 = 74.89; p<0.0001 and the species (F1.215 = 4.72; p<0.0001. Higher mean of intestine length was verified in S. notomelas and a smaller mean in A. anisitsi. Based on dates of diet and morphology, it is possible to conclude that there are trophic segregation between the two species. Thus, the co-existence of these species is possible in function ofthe wide food supply given by aquatic macrophytes.

  1. Determination of Algae and Macrophyte Species Distribution in Three Wastewater Stabilization Ponds Using Metagenomics Analysis

    OpenAIRE

    Wallace, Jack; Champagne, Pascale; Hall, Geof; Yin, Zhaochu; Liu, Xudong

    2015-01-01

    This study involved the evaluation of algae and macrophyte species distributions in three wastewater stabilization ponds (WSPs) at a wastewater treatment plant in Ontario, Canada, which has experienced high pH levels at the final effluent and excessive algae growth during the summer since 2003. From samples collected from the system, the relative abundances of specific algae and aquatic plant (macrophyte) taxa were assessed and correlated to water chemistry data. A strong shift from the domin...

  2. One-dimensional Modeling of Macrobyte growth : part of the study Macrophytes and nutriments Dynamics in the upperreaches of the Scheldt Bassin

    OpenAIRE

    Strömbom, Susan

    2004-01-01

    Massive macrophyte development in the Flemish running waters in the northern part ofBelgium is a result of the improved water quality regarding organic loads in combination witha continuous high nutrient input. Since the macrophytes, higher aquatic plants with roots andstems, are contributing to the flooding problem in the Flemish regions by raising the waterlevel in rivers where the water level already is high, the macrophyte management is animportant issue in the Flemish areas. There are fe...

  3. Macrophytes in estuarine gradients: Flow through flexible vegetation

    OpenAIRE

    Dijkstra, J.T.

    2012-01-01

    Aquatic plants –or macrophytes- are an important part of coastal, estuarine and freshwater ecosystems worldwide, both from an ecological and an engineering viewpoint. Their meadows provide a wide range of ecosystem services: forming a physical protection of the shoreline, enhancing water quality and harbouring many other organisms. Unfortunately, these vegetations such as salt marshes, seagrasses or mangroves have been on the decline as a result of anthropogenic pressure and climate change, d...

  4. Emissions of methane and carbon dioxide during anaerobic decomposition of aquatic macrophytes from a tropical lagoon (São Paulo, Brazil Emissões de metano e dióxido de carbono da decomposição de macrófitas aquáticas de uma lagoa tropical (São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Irineu Bianchini Jr.

    2010-06-01

    Full Text Available AIM: Massive accumulations of aquatic sedimentary plant are the main source of CH4 and CO2 emissions in floodplain lakes. To examine this connection, this study measured CO2 and CH4 formation during anaerobic decomposition of aquatic macrophytes from a floodplain lake; METHODS: Methane formation was determined to the intrinsic characteristics of the debris, and the experimental (physical and chemical conditions. Production of CH4 and CO2 were measured during anaerobic degradation of seven aquatic macrophytes: Cabomba furcata, Cyperus giganteus, Egeria najas, Eichhornia azurea, Ludwigia inclinata, Oxycaryum cubense, and Utricularia breviscapa, all of which inhabit the littoral zone of the lagoon studied; RESULTS: Overall, methanogenesis was more sensitive to temperature variation than gross anaerobic mineralization. Although the metabolic routes that generate CO2 were always predominant, as a competing process methanogenesis was favored by increasing temperature to the detriment of CO2 formation. Although several factors (such as pH, redox potential, salinity and nutrients availability influenced yields of the final degradation products, temperature and detritus chemical composition were, in a first approach, the key factors in CH4 formation. In the oxbow lakes of the Mogi-Guaçu River Floodplain, especially Óleo Lagoon, on average, 10% of the total carbon can be regarded as the yield of CH4 formation derived from aquatic macrophyte decay, while the remaining carbon (90% became CO2.OBJETIVO: Acúmulos intensos de plantas nos sedimentos são importantes fontes de emissões de CH4 e CO2 em lagoas de várzea de inundação. Nesse estudo foram determinadas as formações de CH4 e CO2 da decomposição anaeróbia de macrófitas aquáticas de uma lagoa marginal; MÉTODOS: A formação do metano foi determinada com base nas características intrínsecas dos detritos e das condições experimentais. As produções de CH4 e CO2 foram determinadas durante

  5. Submersible Generator for Marine Hydrokinetics

    Energy Technology Data Exchange (ETDEWEB)

    Cinq-Mars, Robert S; Burke, Timothy; Irish, James; Gustafson, Brian; Kirtley, James; Alawa, Aiman

    2011-09-01

    A submersible generator was designed as a distinct and critical subassembly of marine hydrokinetics systems, specifically tidal and stream energy conversion. The generator is designed to work with both vertical and horizontal axis turbines. The final product is a high-pole-count, radial-flux, permanent magnet, rim mounted generator, initially rated at twenty kilowatts in a two-meter-per-second flow, and designed to leverage established and simple manufacturing processes. The generator was designed to work with a 3 meter by 7 meter Gorlov Helical Turbine or a marine hydrokinetic version of the FloDesign wind turbine. The team consisted of experienced motor/generator design engineers with cooperation from major US component suppliers (magnetics, coil winding and electrical steel laminations). Support for this effort was provided by Lucid Energy Technologies and FloDesign, Inc. The following tasks were completed: Identified the conditions and requirements for MHK generators. Defined a methodology for sizing and rating MHK systems. Selected an MHK generator topology and form factor. Completed electromechanical design of submersible generator capable of coupling to multiple turbine styles. Investigated MHK generator manufacturing requirements. Reviewed cost implications and financial viability. Completed final reporting and deliverables

  6. African Journal of Aquatic Science - Vol 42, No 3 (2017)

    African Journals Online (AJOL)

    Activity of some Nile River aquatic macrophyte extracts against the cyanobacterium Microcystis aeruginosa · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M El-Sheekh, AM Haroon, S Sabae, 271-277 ...

  7. A preliminary evaluation of lake morphometric traits influence on the maximum growing depth of macrophytes

    Directory of Open Access Journals (Sweden)

    Mattia M. Azzella

    2014-03-01

    Full Text Available Underwater light regime is widely considered the principal determinant of aquatic plant depth distribution. The majority of previous studies dealing with macrophytes in lakes have singled out Secchi disk transparency (SD values as the key empirical proxy to explain the maximum depth of macrophyte colonization (Zc. Few studies have investigated the role played by lake morphometry in structuring macrophyte beds. Using a balanced dataset including 20 Italian lakes (10 shallow and 10 deep lakes, we analysed transparency and lake morphometric traits to investigate their possible effects on Zc. Our results demonstrate that lake area plays a significant role, and confirm a direct influence of SD values on Zc. Considering lakes with an equal degree of transparency, smaller lakes may yield a lower Zc than larger ones. Morphology has a great influence on lake ecological characteristics especially on water thermal conditions and mixing depth. Based on our data, we argue that the thermal stratification plays a non negligible role in explaining macrophytes zonation, due to its influence on macrophytes life cycles and phytoplankton vertical distribution. Therefore, the present data suggest the need to enhance and refine our knowledge about the relationship between aquatic plants distribution and lake thermal conditions to better model the response of macrophytes to climate change and eutrophication.

  8. Inorganic carbon shortage may limit the development of submersed macrophytes in habitats of the Paraná River basin Baixas concentrações de carbono inorgânico podem limitar o desenvolvimento de macrófitas submersas em habitats do alto rio Paraná

    Directory of Open Access Journals (Sweden)

    Aline de Freitas

    2011-03-01

    Full Text Available AIM: In this investigation we carried out an experiment to assess whether the growth of Egeria najas and E. densa (two rooted submersed Hydrocharitacea, native to South America are limited by inorganic carbon or not; METHODS: We measured the early plant growth in 3 L microcosms with alkalinities of 100 µM.L-1 and 500 µM.L-1. These alkalinites represent extremes which are typical of most waters in the Upper Paraná River basin and they represent low and high inorganic carbon (mainly bicarbonate availabilities, respectively; RESULTS: The elongation of E. densa, and the relative growth rates and root development of both species were significantly higher when they grew in the high alkalinity treatment; CONCLUSIONS: Our results strongly suggest that in several habitats and during certain periods of the year, inorganic carbon shortage may limit the growth of both species. In this sense, phosphorus and nitrogen may assume a secondary role as controlling factors of these plants, because they assimilate these nutrients from sediment, where they are usually found in high concentrations. Thus, controlling eutrofication as a strategy to reduce their biomass may not be successful.OBJETIVOS: Nesse trabalho nós realizamos um experimento para avaliar se o crescimento de Egeria najas e E. densa (duas espécies de macrófitas aquáticas submersas da família Hydrocharitaceae, nativas da América do Sul é limitado por carbono inorgânico; MÉTODOS: Nós medimos os estágios iniciais de crescimento de fragmentos em microcosmos de 3 L com alcalinidade de 100 µM.L-1 e 500 µM.L-1. Esses valores de alcalinidade foram escolhidos por representarem extremos típicos da maioria dos ecossistemas aquáticos da bacia do Alto rio Paraná e representaram baixa e alta disponibilidade de carbono (principalmente bicarbonato, respectivamente; RESULTADOS: O alongamento de E. densa e o crescimento relativo e desenvolvimento de raízes de ambas as espécies foram

  9. The role of macrophyte structural complexity and water flow velocity in determining the epiphytic macroinvertebrate community composition in a lowland stream

    NARCIS (Netherlands)

    Wolters, Jan Willem; Verdonschot, Ralf C.M.; Schoelynck, Jonas; Verdonschot, Piet F.M.; Meire, Patrick

    2018-01-01

    Habitat structural complexity provided by aquatic macrophytes in lowland streams affects the associated epiphytic macroinvertebrate assemblages in both direct (increased microhabitat diversity, refuge against predation) and indirect ways (e.g. current attenuation by physical structures). In a

  10. 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

    Directory of Open Access Journals (Sweden)

    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

  11. Iron addition as a measure to restore water quality : Implications for macrophyte growth

    NARCIS (Netherlands)

    Immers, A. K.; Vendrig, K.; Ibelings, B. W.; Van Donk, E.; Ter Heerdt, G. N. J.; Geurts, J. J. M.; Bakker, E. S.

    Eutrophication of shallow lakes in North-West Europe has resulted in cyanobacterial blooms, turbid water, and a decline in submerged macrophytes. Even though external inputs of phosphorus (P) are declining, internal loading of P from the sediment may delay the recovery of these aquatic ecosystems.

  12. Closely related freshwater macrophyte species, Ceratophyllum demersum and C. submersum, differ in temperature response

    DEFF Research Database (Denmark)

    Hyldgaard, Benita; Sorrell, Brian Keith; Brix, Hans

    2014-01-01

    1. The importance of temperature responses of photosynthesis and respiration in determining species distributions was compared in two closely related freshwater macrophytes, Ceratophyllum demersum and C. submersum. The two species differed significantly in response to temperature in the short...... optimum. Hence, this study highlights key issues that need to be examined carefully to improve models predicting future temperature responses of aquatic plants....

  13. Iron addition as a measure to restore water quality: Implications for macrophyte growth

    NARCIS (Netherlands)

    Immers, A.; Vendrig, K.; Ibelings, B.W.; Van Donk, E.; Ter Heerdt, G.; Geurts, J.J.M.; Bakker, E.S.

    2014-01-01

    Eutrophication of shallow lakes in North-West Europe has resulted in cyanobacterial blooms, turbid water, and a decline in submerged macrophytes. Even though external inputs of phosphorus (P) are declining, internal loading of P from the sediment may delay the recovery of these aquatic ecosystems.

  14. Interaction between the macrophyte Stratiotes aloides and filamentous algae: does it indicate allelopathy?

    NARCIS (Netherlands)

    Mulderij, G.; Mau, B.; De Senerpont Domis, L.N.; Smolders, A.J.P.; Van Donk, E.

    2009-01-01

    The aquatic macrophyte Stratiotes aloides Linnaeus, which has recently received attention in studies on allelopathy, has been shown to suppress phytoplankton growth. In the Netherlands, S. aloides often co-occurs with floating filamentous algae. However, filamentous algae are generally absent in

  15. Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

    2016-04-01

    Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

  16. 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...

  17. Biomass production of the aquatic macrophytes Eichhornia crassipes (water hyacinth and Egeria densa (egeria in organic fish farm effluent treatment system / Produção de biomassa das macrófitas aquáticas Eichhornia crassipes (aguapé e Egeria densa (egeria em sistema de tratamento de efluente de piscicultura orgânica

    Directory of Open Access Journals (Sweden)

    Anderson Coldebella

    2008-08-01

    Full Text Available The objective of this research was to evaluate the production of biomass of the aquatic macrophytes water hyacinth (Eichhornia crassipes and egeria (Egeria densa in three hydraulic detention times in a organic pisciculture effluent treatment system. The system was composed for 18 experimental tanks of 2.00 x 1.00 x 0.65m length, width and depth respectively, coated with polypropylene canvas. An entirely randomized 2 macrophytes x 3 hydraulic detention times (HDT and 3 repetitions. The HDT used was 4, 8, and 12 hours. The biomass production was evaluated at the end of the experiment which was extended at 08/07 to 19/08/2006. The water hyacinth showed the best results of biomass production (P0.05. For egeria the treatment that presented the best production of biomass was reached which TDH of 12 hours, being of 0.10 kg.m-2, followed for the HDT of 8 and 4 hours, not differing between the HDT (P>0.05. One concludes that the water hyacinth produced higher biomass than egeria in all of the HDT evaluated.O presente trabalho teve por o objetivo avaliar a produção de biomassa das macrófitas aquáticas aguapé (Eichhornia crassipes e egeria (Egeria densa em um sistema de tratamento de efluente de piscicultura orgânica, sob 3 condições de tempo de detenção hidráulica. O sistema foi composto por 18 tanques experimentais de 2,00 x 1,00 x 0,65 m de comprimento, largura e profundidade, respectivamente, revestidos com lona de polipropileno. O delineamento foi inteiramente casualizado, com 2 macrófitas, 3 tempos de detenção hidráulica (TDH e 3 repetições. Os TDH utilizados foram de 4, 8 e 12 horas. O sistema foi operado de 08/07 a 19/08/2006. A produção de biomassa foi avaliada ao final do experimento. O aguapé apresentou os melhores resultados de produção de biomassa (P0,05. Para a egeria o tratamento que apresentou a melhor produção de biomassa foi no TDH de 12 horas, sendo de 0,10 kg.m- 2, seguido pelos TDH de 8 e 4 horas, não diferindo

  18. Remoção de metais pesados tóxicos cádmio, chumbo e cromo em biofertilizante suíno utilizando macrófita aquática (Eichornia crassipes como bioindicador = Removal of toxic heavy metals cadmium, lead and chromium from swine biofertilizer, using an aquatic macrophyte (Eichornia crassipes as a bioindicator

    Directory of Open Access Journals (Sweden)

    Affonso Celso Gonçalves Júnior

    2008-01-01

    Full Text Available Este trabalho objetivou avaliar a eficiência da macrófita aquática (Eichornia crassipes como bioindicador e alternativa na remoção dos metais pesados tóxicos Cd, Pb e Cr em biofertilizante de origem suína. Foi utilizado o esquema fatorial 2x4, sendo os fatoresrepresentados pelas partes da planta (aérea e raiz, e pelos quatro tratamentos. Na instalação do experimento coletou-se uma alíquota da solução de cada tratamento para determinar as concentrações iniciais dos metais e, após 30 dias de cultivo, as plantas foram retiradas,coletando-se novamente uma alíquota da solução de cada tratamento. As plantas foram separadas em parte aérea e raiz, secas e trituradas. A macrófita apresentou-se eficiente na remoção dos metais pesados, observou-se que o sistema radicular da macrófita apresentoumaiores concentrações de Cd, Pb e Cr. Com este trabalho, conclui-se que a macrófita aquática (Eichornia crassipes pode ser uma alternativa para o tratamento de biofertilizante e dejetos provenientes da suinocultura.The objective of this work was to evaluate the efficiency of an aquatic macrophyte (Eichornia crassipes as a bioindicator and as an alternative sorbent for the removal of toxic heavy metals Cd, Pb and Cr from swine biofertilizer. A 2x4 factorial design was used, with the factors represented by plant parts (leaves and roots and the fourtreatments. The metal concentrations were determined at the beginning of the experiment and after 30 days. The macrophyte showed good efficiency in the removal of toxic heavy metals from swine biofertilizer. It was observed that its radicular system presented larger amounts of Cd, Pb and Cr than did the leaves. Our results show that Eichornia crassipes could be an alternative treatment for biofertilizer and waste from swine culture.

  19. Emergent Macrophytes Support Zooplankton in a Shallow Tropical Lake: A Basis for Wetland Conservation

    Science.gov (United States)

    Gebrehiwot, Mesfin; Kifle, Demeke; Triest, Ludwig

    2017-12-01

    Understanding the biodiversity value of littoral zones of lakes is a priority for aquatic biodiversity conservation. However, less emphasis has been given to the littoral part of tropical African lakes, with many of the previous researches focusing only on the open water side. The aim of the present study was, therefore, to investigate the impact of the littoral zone of a shallow freshwater tropical lake (Ziway, Ethiopia), dominated by two emergent macrophytes, on zooplankton community structure. We hypothesized that the wetland vegetation serves as a preferred microhabitat for zooplankton communities. A lake with substantial coverage of emergent macrophytes was monitored monthly from January to August, 2016. The monitoring included the measurements of physical, chemical, and biological parameters. Sampling sites were selected to represent areas of the macrophyte vegetation ( Typha latifolia and Phragmites australis) and the open water part of the lake. Sites with macrophyte vegetation were found to be the home of more dense and diverse zooplankton community. However, during the period of high vegetation loss, the density of crustacean zooplankton showed significant reduction within the patches of macrophytes. From biodiversity conservation perspective, it was concluded that the preservation of such small areas of macrophytes covering the littoral zone of lakes could be as important as protecting the whole lake. However, the rapid degradation of wetland vegetation by human activities is a real threat to the lake ecosystem. In the not-too-far future, it could displace and evict riparian vegetation and the biota it supports.

  20. 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.

  1. Effects of eutrophication and temperature on submersed rooted plants

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl

    , especially at high temperatures. Results also showed that growth of Z. marina plants at higher temperatures will be reduced at gradually lower oxygen concentrations. The tropical seagrasses were surprisingly tolerant to oxygen depletion in the water column and none of them showed reduced growth within the 72......Aquatic macrophytes have during the last decades faced a massive decline of coverage and repeated die‐off events have been detected for freshwater (Sand‐Jensen et al., 2000) and marine plants (Waycott et al., 2009). Increased nutrient loading has been suggested to play a central role, because high...... and degradation of dying alga blooms accelerate the microbial activity and thereby intensify oxygen consumption in sediment and water column. This oxygen consumption may accelerate further by increasing temperature caused by warmer climate. This thesis examines how low sediment and water column oxygen levels...

  2. Determination of Algae and Macrophyte Species Distribution in Three Wastewater Stabilization Ponds Using Metagenomics Analysis

    Directory of Open Access Journals (Sweden)

    Jack Wallace

    2015-06-01

    Full Text Available This study involved the evaluation of algae and macrophyte species distributions in three wastewater stabilization ponds (WSPs at a wastewater treatment plant in Ontario, Canada, which has experienced high pH levels at the final effluent and excessive algae growth during the summer since 2003. From samples collected from the system, the relative abundances of specific algae and aquatic plant (macrophyte taxa were assessed and correlated to water chemistry data. A strong shift from the dominance of green algae, chlorophyceae, in WSP#2, to the dominance of aquatic macrophytes, embryophyta, in WSP#4, was observed and corresponded to field observations. Correlation of the abundances to nutrient parameters suggested that the macronutrient rich conditions in WSP#2 allowed floating green algae to proliferate against macrophytes. In WSP#1 and WSP#4, macrophytes competed against algae and thrived, due to their adaptability to lower nutrient conditions. The pH increases occurred primarily in WSP#2 and were not buffered or reduced in WSP#1 and WSP#4. Two alternatives strategies for pH control were recommended for the system: decreasing algae growth in WSP#2 through duckweed seeding or macronutrient loading reduction; or designing and implementing a constructed wetland (CW in WSP#4 with soil and vegetation to buffer pH prior to release.

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

    Science.gov (United States)

    Wolverton, B. C.

    1975-01-01

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

  4. Macrophytes of the Grlište reservoir (Serbia: Fifteen years after its establishment

    Directory of Open Access Journals (Sweden)

    Stanković Ž.

    2009-01-01

    Full Text Available A large number of macrophytes, often in dense populations, have developed on the Grlište Reservoir, Serbia over a period of 15 years. Fast development of vegetation is a consequence of anthropogenic impact in lake management. The methodology used in this research covered 100% of the water body, including all areas with or without aquatic plants. The results indicate that plant communities are still in the early phase of development. This leaves space for future development of competitor macrophyte species (Najas marina, Eleocharis palustris, Typha latifolia, Typha angustifolia, Phragmites australis, etc. capable of endangering stability of the lake, which will tend toward eutrophication.

  5. Digestibilidade aparente de macrófitas aquáticas pela tilápia-do-nilo (Oreochromis niloticus e qualidade da água em relação às concentrações de nutrientes Apparent digestibility of aquatic macrophytes by Nile tilapia (Oreochromis niloticus and water quality in relation nutrients concentrations

    Directory of Open Access Journals (Sweden)

    Gustavo Gonzaga Henry-Silva

    2006-06-01

    Full Text Available Objetivou-se com este estudo determinar os coeficientes de digestibilidade aparente (CDA da proteína bruta e dos aminoácidos de duas espécies de macrófitas aquáticas flutuantes (Eichhornia crassipes e Pistia stratiotes pela tilápia-do-nilo (Oreochromis niloticus e verificar a qualidade da água dos aquários de digestibilidade em relação às concentrações de nitrogênio e fósforo. Foram elaboradas três rações, marcadas com 0,10% de óxido de cromo-III, sendo uma ração-referência (purificada e as demais contendo 30% de cada uma das macrófitas aquáticas. As tilápias-do-nilo (58,8 + 18,5 g foram alimentadas até a saciedade aparente e a coleta de fezes foi feita pelo sistema Guelph modificado. Os CDA médios da proteína e dos aminoácidos foram, respectivamente, 93,17 e 93,32% para a ração-referência; 59,23 e 60,35% para E. crassipes; e 52,24 e 57,40% para P. stratiotes. Não foram constatadas diferenças significativas entre os valores de CDA da proteína e dos aminoácidos dos ingredientes vegetais. Os resultados obtidos demonstraram reduzida eficiência da tilápia-do-nilo em assimilar a maioria dos aminoácidos de E. crassipes e P. stratiotes. As excretas das tilápias-do-nilo contribuíram para o aumento das concentrações de nitrogênio e fósforo na água dos aquários, independentemente da ração fornecida.The objectives of this trial were to determine the apparent digestibility coefficients (ADC of crude protein and amino acids for two species of free floating aquatic macrophytes (Eichhornia crassipes and Pistia stratiotes by Nile tilapia (Oreochromis niloticus and to determine the water quality of digestibility aquariums in relation nitrogen and phosphorus concentrations. Tree feeds were developments, containing 0.10% of chromic oxide - III, one being the reference diet (purified and the others containing 30% of aquatic macrophytes. The Nile tilapias (58.8 + 18.5 g were fed to apparent satiation and the faeces

  6. Influence of temperature and salinity on heavy metal uptake by submersed plants

    Energy Technology Data Exchange (ETDEWEB)

    Fritioff, A. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden)]. E-mail: fritioff@botan.su.se; Kautsky, L. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden); Greger, M. [Department of Botany, Stockholm University, S-106 91 Stockholm (Sweden)

    2005-01-01

    Submersed plants can be useful in reducing heavy metal concentrations in stormwater, since they can accumulate large amounts of heavy metals in their shoots. To investigate the effects of water temperature and salinity on the metal uptake of two submersed plant species, Elodea canadensis (Michx.) and Potamogeton natans (L.), these plants were grown in the presence of Cu, Zn, Cd, and Pb at 5, 11, and 20 deg. C in combination with salinities of 0, 0.5, and 5%o. The metal concentrations in the plant tissue increased with increasing temperature in both species; the exception was the concentration of Pb in Elodea, which increased with decreasing salinity. Metal concentrations at high temperature or low salinity were up to twice those found at low temperature or high salinity. Plant biomass affected the metal uptake, with low biomass plants having higher metal concentrations than did high biomass plants. - Metal concentrations increase with increasing temperature and decreasing salinity in two aquatic plants.

  7. 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...

  8. LBA-ECO LC-07 Aquatic Marcophyte Biomass, Monte Alegre Lake, Para, Brazil: 2003-2004

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports measurements of aquatic macrophyte biomass, phenology, leaf characteristics, and length and diameter of stems of both submerged and unsubmerged...

  9. LBA-ECO LC-07 Aquatic Marcophyte Biomass, Monte Alegre Lake, Para, Brazil: 2003-2004

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports measurements of aquatic macrophyte biomass, phenology, leaf characteristics, and length and diameter of stems of both submerged and...

  10. The Submersible Threat to Maritime Homeland Security

    Science.gov (United States)

    2013-09-01

    research would be how the HSE could possibly utilize small submersibles to enhance HS through such activities as using remotely operated subs to conduct...1 C. RESEARCH QUESTION AND METHODOLOGY ...................................4 D. SIGNIFICANCE TO THE FIELD...Technology ...................................................66 C. RECOMMENDATIONS FOR FUTURE RESEARCH .............................68 D. CONCLUSION

  11. Effect of Urucu oil (Brazilian Amazon on the biomass of the aquatic macrophyte Eichhornia crassipes (Mart. Solms (Pontederiaceae Efeito do petróleo de Urucu (Amazônia/Brasil sobre a biomassa da macrófita aquática Eichhornia crassipes (Mart. Solms (Pontederiaceae

    Directory of Open Access Journals (Sweden)

    Luciana Carvalho Crema

    2011-12-01

    Full Text Available The rivers and floodplain lakes of the Urucu petroleum-bearing region in central Amazonia are extensively colonized by aquatic macrophytes, which may be affected by accidental spills during oil extraction and transportation operations. Among the species of macrophytes, the free-floating Eichhornia crassipes (water hyacinth is abundant; AIM: The objective of this study was to evaluate the effect of different dosages of Urucu crude oil (0, 0.5, 1.5 and 3.0 L.m-2 on the biomass of E. crassipes and on some physical and chemical characteristics of the water in which the plant grew; METHODS: The experiment was conducted over a period of 84 days. Every seven days, the biomass (live and dead of E. crassipes and the temperature, pH, electrical conductivity and dissolved oxygen in the water were measured; RESULTS: The dosage of 0.5 L.m-2 was sufficient to cause partial mortality (48% in E. crassipes after 35 days of exposure to oil. The dosage of 3.0 L.m-2 caused total mortality (100% in E. crassipes after 84 days of exposure. The decomposition of the oil and the dead biomass of E. crassipes reduced the dissolved oxygen and pH, and increased electrical conductivity and concentrations of total phosphorus in the water; CONCLUSIONS: We conclude that an oil spill can cause total mortality in the local population of one macrophyte species, but not of another. This may alter the macrophyte species diversity in the impacted region. In the case of E. crassipes and Pistia stratiotes, an Urucu crude oil spill could favor E. crassipes, the species less sensitive to oil.Os rios e lagos de várzea da província petrolífera de Urucu, na Amazônia Central, são amplamente colonizados por macrófitas aquáticas, que podem ser afetadas por acidentes durante a exploração e o transporte de petróleo. Entre as macrófitas, a espécie flutuante Eichhornia crassipes (aguapé ocorre abundantemente na região; OBJETIVO: O objetivo desse estudo foi verificar o efeito de

  12. Invasive Macrophytes Control the Spatial and Temporal Patterns of Temperature and Dissolved Oxygen in a Shallow Lake: A Proposed Feedback Mechanism of Macrophyte Loss.

    Science.gov (United States)

    Vilas, Maria P; Marti, Clelia L; Adams, Matthew P; Oldham, Carolyn E; Hipsey, Matthew R

    2017-01-01

    Submerged macrophytes can have a profound effect on shallow lake ecosystems through their ability to modify the thermal structure and dissolved oxygen levels within the lake. Invasive macrophytes, in particular, can grow rapidly and induce thermal gradients in lakes that may substantially change the ecosystem structure and challenge the survival of aquatic organisms. We performed fine-scale measurements and 3D numerical modeling at high spatiotemporal resolution to assess the effect of the seasonal growth of Potamogeton crispus L. on the spatial and temporal dynamics of temperature and dissolved oxygen in a shallow urban lake (Lake Monger, Perth, WA, Australia). Daytime stratification developed during the growing season and was clearly observed throughout the macrophyte bed. At all times measured, stratification was stronger at the center of the macrophyte bed compared to the bed edges. By fitting a logistic growth curve to changes in plant height over time ( r 2 = 0.98), and comparing this curve to temperature data at the center of the macrophyte bed, we found that stratification began once the macrophytes occupied at least 50% of the water depth. This conclusion was strongly supported by a 3D hydrodynamic model fitted to weekly temperature profiles measured at four time periods throughout the growing season ( r 2 > 0.78 at all times). As the macrophyte height increased and stratification developed, dissolved oxygen concentration profiles changed from vertically homogeneous oxic conditions during both the day and night to expression of night-time anoxic conditions close to the sediments. Spatially interpolated maps of dissolved oxygen and 3D numerical modeling results indicated that the plants also reduced horizontal exchange with surrounding unvegetated areas, preventing flushing of low dissolved oxygen water out of the center of the bed. Simultaneously, aerial imagery showed central dieback occurring toward the end of the growing season. Thus, we hypothesized

  13. Invasive Macrophytes Control the Spatial and Temporal Patterns of Temperature and Dissolved Oxygen in a Shallow Lake: A Proposed Feedback Mechanism of Macrophyte Loss

    Directory of Open Access Journals (Sweden)

    Maria P. Vilas

    2017-12-01

    Full Text Available Submerged macrophytes can have a profound effect on shallow lake ecosystems through their ability to modify the thermal structure and dissolved oxygen levels within the lake. Invasive macrophytes, in particular, can grow rapidly and induce thermal gradients in lakes that may substantially change the ecosystem structure and challenge the survival of aquatic organisms. We performed fine-scale measurements and 3D numerical modeling at high spatiotemporal resolution to assess the effect of the seasonal growth of Potamogeton crispus L. on the spatial and temporal dynamics of temperature and dissolved oxygen in a shallow urban lake (Lake Monger, Perth, WA, Australia. Daytime stratification developed during the growing season and was clearly observed throughout the macrophyte bed. At all times measured, stratification was stronger at the center of the macrophyte bed compared to the bed edges. By fitting a logistic growth curve to changes in plant height over time (r2 = 0.98, and comparing this curve to temperature data at the center of the macrophyte bed, we found that stratification began once the macrophytes occupied at least 50% of the water depth. This conclusion was strongly supported by a 3D hydrodynamic model fitted to weekly temperature profiles measured at four time periods throughout the growing season (r2 > 0.78 at all times. As the macrophyte height increased and stratification developed, dissolved oxygen concentration profiles changed from vertically homogeneous oxic conditions during both the day and night to expression of night-time anoxic conditions close to the sediments. Spatially interpolated maps of dissolved oxygen and 3D numerical modeling results indicated that the plants also reduced horizontal exchange with surrounding unvegetated areas, preventing flushing of low dissolved oxygen water out of the center of the bed. Simultaneously, aerial imagery showed central dieback occurring toward the end of the growing season. Thus, we

  14. Remote Sensing supports EULAKES project for mapping submerged macrophytes in Lake Garda

    Science.gov (United States)

    Matta, Erica; Bresciani, Mariano; Giardino, Claudia; Bolpagni, Rossano; Pellegrini, Giovanna; Braga, Federica

    2013-04-01

    Lake bottoms have an important role in the aquatic ecosystem: bathymetry and morphology may affect the hydrodynamic processes in coastal waters, while the presence of aquatic macrophytes helps to preserve the ecology. Within the context of macrophyte monitoring programs, technical advances in remote sensing with higher spatial and spectral resolutions provide opportunities for big scale ecological studies, with the possibility to assess a multitemporal analysis. One of the objectives of the EULAKES project has been to map aquatic vegetation cover inside the Garda Lake from hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) aerial images thanks to the application of a bio-optical model inversion technique (BOMBER: Bio-Optical Model Based tool for Estimating water quality and bottom properties from Remote sensing images). MIVIS images, with a spectral resolution of 102 bands, working between 430 and 1270 nm, were previously corrected for atmospheric, adjacency and glint effects before being processed with the BOMBER tool. One complete MIVIS overflight (12 runs) acquired on June 27th 2011, allowed the retrieval of a macrophyte presence map all around the first 7m deep coastal belt, with a validation error of about 10%, resulting from 89 in situ measures performed during images acquisition. A relevant spatial distribution could be observed, with higher aquatic plants concentration in the Southern part of the lake. A further local cover distribution map localized on the Sirmione Peninsula was integrated with previous results to perform a temporal analysis of macrophyte colonization patterns along this reduced littoral zone for the last 14 years (acquisitions on September 1997, July 2005 and July 2010). Considerable modifications in terms of macrophyte structural complexity and colonized areas were detectable: a drastic reduction of well-established dense communities (more than 70% of cover) and increasing of un-colonized areas were followed by

  15. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 1. Baseline Studies. Volume II. The Fish, Mammals, and Waterfowl of Lake Conway, Florida.

    Science.gov (United States)

    1979-12-01

    reduced. b. White amur recycle nutrients bound in aquatic macrophytes , possibly increasing the nutrient level in the water so that problems of... eutrophication , plankton blooms, and filamentous algae are aggravated. c. Sport fish population production may decline due to sim- ple displacement, direct...level fluctuations, seasonal succession of aquatic macrophytes , water quality, physical alterations, and other factors. Of course in some instances

  16. Simple relationships to predict attributes of fish assemblages in patches of submerged macrophytes

    Directory of Open Access Journals (Sweden)

    Fernando Mayer Pelicice

    Full Text Available Submerged macrophytes play an important role in structuring habitats and, therefore, in determining patterns of aquatic biodiversity. Because these plants are widespread in shallow areas of many Neotropical reservoirs, the present work investigated if variables related to habitat structure, measured in patches of submerged macrophytes (Egeria densa and E. najas, can be used to predict fish assemblage attributes (fish density and species richness. Based on patch characteristics at fine spatial extents (macrophyte patches within reservoir arms, we considered plant biomass, volume and proportional volume (i.e. percentage of macrophyte volume in the water column as potential predictors. Fish and macrophytes were sampled with a 1-m² throw trap in littoral habitats of Rosana Reservoir, Paranapanema River, and simple correlation analyses were performed. Fish richness and abundance were highly correlated with all variables (R = 0.53 to 0.90, a relationship consistently observed in all sites. When compared to biomass, plant volume and proportional volume did not yield stronger correlations. We observed stronger correlations when E. densa and E. najas patches were analyzed separately (mono-specificity, probably because particular effects of each macrophyte on habitat structuring were removed (e.g. unnoticed morphological differences or unknown effects on habitat quality. The high R values observed in all pairwise relationships are uncommon in ecological studies, highlighting the predictive potential of variables related to habitat structure. These results suggest that, at small spatial extents, macrophyte biomass may represent an interesting predictor of fish density and richness in reservoirs with extensive colonization of submerged plants.

  17. Spatial and temporal dynamics of macrophyte cover in a large regulated river.

    Science.gov (United States)

    Tena, A; Vericat, D; Gonzalo, L E; Batalla, R J

    2017-11-01

    The River Ebro basin is extensively dammed. Dams alter the geomorphological functioning of the river by altering its flow regime (e.g. reducing mean and maximum discharges), increasing bed stability (armouring) and decreasing turbidity (water clarity). These effects, together with an increase in nutrient concentrations and water temperature, have generated optimal conditions for the proliferation of aquatic macrophytes. In this paper, we analyse the temporal and spatial changes of macrophyte cover in the lowermost Ebro through a series of field campaigns carried out between 2009 and 2010. Special attention was paid to the spatial distribution of macrophytes in relation to flow hydraulics, channel geometry and bed sedimentology. Temporal changes in macrophyte cover were analysed in relation to the frequency and magnitude of both natural floods and flushing flows (artificial flow releases from dams with generally a magnitude that equates around a2-year flood in the river). Spatially, the proportion of macrophytes along the reaches showed a variable pattern, with a succession of areas with both high and low plant density, coinciding with the alternation of riffles and pools in the channel. The highest values of plant cover (>65%) occurred in riffles and in transition to riffle areas, while the lowest densities (1% or almost negligible) were observed in pools and transition to pool areas. Water depth and the grain-size distribution of the riverbed materials (i.e. D84), are found to be the main factors controlling the degree of plant cover in the lower Ebro. Temporally, the macrophyte proportion varied during the hydrological year, with a clear increment from late spring to early autumn (i.e. vegetation cover reached 40%, on average, of the channel surface). Macrophyte coverage decreases immediately following a flushing flow but in the long term, vegetation re-occupied the area again, even slightly increasing in some sections; overall, the mean percentage of macrophyte

  18. A macrophyte bioassessment approach linking taxon-specific tolerance and abundance in north temperate lakes.

    Science.gov (United States)

    Mikulyuk, Alison; Barton, Martha; Hauxwell, Jennifer; Hein, Catherine; Kujawa, Ellen; Minahan, Kristi; Nault, Michelle E; Oele, Daniel L; Wagner, Kelly I

    2017-09-01

    Bioassessment methods are critically needed to evaluate and monitor lake ecological condition. Aquatic macrophytes are good candidate indicators, but few lake bioassessment methods developed in North America use them. The few macrophyte bioassessment methods that do exist suffer from problems related to subjectivity and discernibility along disturbance gradients. We developed and tested a bioassessment approach for 462 north temperate lakes. The approach links macrophyte abundance to lake ecological condition via estimates of taxon-specific abundance-weighted tolerance to anthropogenic disturbance. Using variables related to eutrophication, urban development and agriculture, we calculated abundance-weighted tolerance ranges for 59 macrophyte taxa and clustered them according to their tolerance to anthropogenic disturbance. We also created a composite index of anthropogenic disturbance using 20 variables related to population density, land cover and water chemistry. We used a statistical approach to set ecological condition thresholds based on the observed abundance of sensitive, moderately tolerant and tolerant taxa in each lake. The resulting lake condition categories were usually stable across multiple survey events and largely agreed with condition rankings assigned using expert judgment. We suggest using this macrophyte bioassessment method for federal water quality reports, restoration and management on north temperate lakes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

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    Claudia Giardino

    2012-01-01

    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  20. Characterization of phosphorus forms in lake macrophytes and algae by solution 31P nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Aquatic macrophytes and algae are important sources of phosphorus (P) in the lake environment that cause blooms of algae under certain biogeochemical conditions. However, the knowledge of forms of P in these plants and algae and their contribution to internal loads of lake P is very limited. Witho...

  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. 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. Macrófitas aquáticas da lagoa de Jijoca de Jericoacoara, Ceará, Brasil Aquatic macrophytes of Jijoca of Jericoacoara lagoon, Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Lígia Queiroz Matias

    2003-12-01

    Full Text Available A lagoa de Jijoca de Jericoacoara situa-se no litoral do Ceará, Nordeste do Brasil (2º50'10'' e 2º55'32''S - 40º28'32'' e 40º24'09''W, sendo bordejada em sua extremidade Norte por dunas e por vegetação de tabuleiro nas demais faces. Realizou-se o levantamento da composição florística e da estrutura da comunidade de macrófitas aquáticas presentes na lagoa. As amostras das plantas foram coletadas e depositadas no herbário EAC. Densidade, freqüência e cobertura das espécies foram amostradas em 10 transectos plotados em áreas com boas condições de conservação de suas margens, evitando-se áreas urbanas e de atividade agropecuária adjuntas à lagoa. Apresenta-se a lista de 45 espécies ocorrentes, suas formas biológicas e dados da estrutura da comunidade. As espécies com maior índice do valor de importância (IVI foram Eleocharis mutata (L. Roem. & Schult., Paspalidium geminatum Stapf, Eleocharis atropurpurea (Retz. Kunth, Nymphoides indica (L. Kuntze e Echinodorus tenellus (Mart. Buchen. A forma de vida predominante foi "plantas enraizadas ao substrato - anfíbias tolerantes à seca". Em relação à profundidade, ocorre aumento da diversidade de espécies de áreas mais profundas para 0-0,5m de espessura da lâmina d'água.The Jijoca of Jericoacoara lake is located at Ceará Coastal Zone, Northeast of Brazil (2º50'10'' e 2º55'32''S - 40º28'32'' e 40º24'09''W, and it has sand dunes on the Northern shore and arboreal semi-deciduous vegetation around the other lakesides. A floristic and communities structure survey of aquatic flora was conducted. Plant samples were collected and included in the EAC Herbarium. The density, frequency, and cover were measurements used in describing communities by intercept transect sampling. Sampling was carried out in Jijoca of Jericoacoara lake at 10 localities, except areas with human impact, such as urban and agricultural areas. A list of 45 species, their life forms and vegetation

  4. Relative importance of P and N in macrophyte and epilithic algae biomass in a wastewater-impacted oligotrophic river.

    Science.gov (United States)

    Taube, Nadine; He, Jianxun; Ryan, M Cathryn; Valeo, Caterina

    2016-08-01

    The role of nutrient loading on biomass growth in wastewater-impacted rivers is important in order to effectively optimize wastewater treatment to avoid excessive biomass growth in the receiving water body. This paper directly relates wastewater treatment plant (WWTP) effluent nutrients (including ammonia (NH3-N), nitrate (NO3-N) and total phosphorus (TP)) to the temporal and spatial distribution of epilithic algae and macrophyte biomass in an oligotrophic river. Annual macrophyte biomass, epilithic algae data and WWTP effluent nutrient data from 1980 to 2012 were statistically analysed. Because discharge can affect aquatic biomass growth, locally weighted scatterplot smoothing (LOWESS) was used to remove the influence of river discharge from the aquatic biomass (macrophytes and algae) data before further analysis was conducted. The results from LOWESS indicated that aquatic biomass did not increase beyond site-specific threshold discharge values in the river. The LOWESS-estimated biomass residuals showed a variable response to different nutrients. Macrophyte biomass residuals showed a decreasing trend concurrent with enhanced nutrient removal at the WWTP and decreased effluent P loading, whereas epilithic algae biomass residuals showed greater response to enhanced N removal. Correlation analysis between effluent nutrient concentrations and the biomass residuals (both epilithic algae and macrophytes) suggested that aquatic biomass is nitrogen limited, especially by NH3-N, at most sampling sites. The response of aquatic biomass residuals to effluent nutrient concentrations did not change with increasing distance to the WWTP but was different for P and N, allowing for additional conclusions about nutrient limitation in specific river reaches. The data further showed that the mixing process between the effluent and the river has an influence on the spatial distribution of biomass growth.

  5. Interaction between the macrophyte Stratiotes aloides and filamentous algae: does it indicate allelopathy?

    OpenAIRE

    Mulderij, G.; Mau, B; De Senerpont Domis, L.N.; Smolders, A.J.P.; Donk, E.

    2009-01-01

    The aquatic macrophyte Stratiotes aloides Linnaeus, which has recently received attention in studies on allelopathy, has been shown to suppress phytoplankton growth. In the Netherlands, S. aloides often co-occurs with floating filamentous algae. However, filamentous algae are generally absent in close proximity to S. aloides, resulting in gaps in filamentous algae mats. We analyzed whether those gaps may be caused by allelopathic substances excreted by S. aloides or by nutrient depletion. We ...

  6. Estudo comparativo da dieta, hábitos alimentares e morfologia trófica de duas espécies simpátricas, de peixes de pequeno porte, associados à macrófitas aquáticas - DOI: 10.4025/actascibiolsci.167 Comparative study about diet, feeding habits and trophic morphology of two sympatric species of small fishes in association with aquatic macrophytes- DOI: 10.4025/actascibiolsci.167

    Directory of Open Access Journals (Sweden)

    Valdirene Esgarbossa Loureiro-Crippa

    2007-11-01

    Full Text Available Nesse estudo foram avaliados aspectos da dieta e morfologia trófica de duas espécies simpátricas, uma de Cheirodontinae e uma de Aphyocharacinae, associadas a macrofitas aquáticas, em nove lagoas isoladas da planície de inundação do alto rio Paraná, Brasil, no ano de 2001. A análise da dieta mostrou que Aphyocharax anisitsi consumiu predominantemente microcrustáceos e Serrapinnus notomelas predominantemente algas. A morfologia do trato alimentar, incluindo boca, dentes, rastros branquiais e estômago, apresentou, aparentemente, o mesmo padrão para as duas espécies. Entretanto, os dentes são mais robustos em S. notomelas. Houve interação significativa entre o comprimento padrão (F2,215 = 74,89; p1,215 = 4,72; pS. notomelas e a menor para A. anisitsi, sendo essa diferença significativa. Os dados de dieta e morfologia, analisados conjuntamente, permitem inferir que há segregação trófica entre as duas espécies examinadas. E, ainda, que a co-existência dessas espécies é favorecida pelo amplo suprimento alimentar fornecido pelas macrófitas aquáticas.In this study we analyzed the diet and trophic morphology of two species, one of Cheirodontinae and one of Aphyocharacinae, associated with aquatic macrophytes in nine isolated lagoons of the Paraná river floodplain, Brazil, during 2001. Diet showed that Aphyocharax anisitsi feed mainly on microcrustaceans and Serrapinnus notomelas feed mainly on algae. Trophic morphology, including mouth, tooth, gill rakers and stomach showed apparently the same pattern for the two species. However, teeth are the biggest and the hardest in S. notomelas. Regarding intestine length there was significant interaction between standard length (F2.215 = 74.89; p1.215 = 4.72; pS. notomelas and a smaller mean in A. anisitsi. Based on dates of diet and morphology, it is possible to conclude that there are trophic segregation between the two species. Thus, the co-existence of these species is possible in

  7. Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

    Science.gov (United States)

    Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

    2012-04-01

    Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

  8. Factors involved in spatiotemporal dynamics of submerged macrophytes in a Portuguese coastal lagoon under Mediterranean climate

    Science.gov (United States)

    Antunes, Cristina; Correia, Otília; Marques da Silva, Jorge; Cruces, Anabela; Freitas, Maria da Conceição; Branquinho, Cristina

    2012-09-01

    Submerged macrophytes are key in coastal ecosystems, with important structural and functional roles. Thus, the characterization of the submerged aquatic vegetation dynamics is of prime importance for assessing the ecological status of coastal ecosystems. The main aim of this study was to assess the spatial and temporal dynamics of submerged macrophytes biomass in a temporarily open coastal lagoon in Melides, Portugal, and to evaluate the physiological performance of the dominant macrophyte in the system. This lagoon is subject to several disturbances such as the dramatic changes in water physicochemical parameters over time, since temporarily opens to the sea occur renewing the lagoon water content. Moreover it is under a Mediterranean climate with the inherently high temporal variability of precipitation and high temperatures during the summer. Our study shows that the submerged macrophyte community was dominated initially by Ruppia cirrhosa and then replaced by Potamogeton pectinatus, which showed a marked temporal and spatial pattern with extremely high values of biomass in August and in the inner part of the lagoon. The spatial and temporal biomass patterns in submerged macrophytes were mainly related with water level, salinity, pH and transparency. The physiological performance of R. cirrhosa was lower when there was greater biomass accumulation and in extremely shallow waters, whereas physiological vigor seemed to be greater at moderate temperatures and in areas with higher salinity and dissolved oxygen. The data from this study can be used to predict submerged biomass macrophyte responses to extreme water quality changes and to feed a decision support system for the best period to promote the seasonal artificial breaching of the sandy barrier.

  9. Macrophytes in the upper Paraná river floodplain: checklist and comparison with other large South American wetlands

    Directory of Open Access Journals (Sweden)

    Fernando Alves Ferreira

    2011-06-01

    Full Text Available Neotropical aquatic ecosystems have a rich aquatic flora. In this report, we have isted the aquatic flora of various habitats of the upper Paraná River floodplain by compiling data rom literature and records of our own continuous collections conducted during the period 2007-2009. Our main purposes were to assess the macrophyte richness in the Paraná floodplain, to compare it with other South American wetlands and to assess whether the number of species recorded in South American inventories has already reached an asymptote. We recorded a total of 153 species of macrophytes in the Upper Paraná River floodplain, belonging to 100 genera and 47 families. In our comparative analysis, a clear floristic split from other South American wetlands was shown, except for the Pantanal, which is the closest wetland to the Paraná floodplain and, therefore, could be considered a floristic extension of the Pantanal. The species accumulation curve provides evidence that sampling efforts should be reinforced in order to compile a macrophyte flora census for South America. The high dissimilarity among South American wetlands, together with the lack of an asymptote in our species accumulation curve, indicates that the sampling effort needs to be increased to account for the actual species richness of macrophytes in this region. Rev. Biol. Trop. 59 (2: 541-556. Epub 2011 June 01.

  10. Cooling devices and methods for use with electric submersible pumps

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Todd Andrew; Gamboa, Jose A

    2017-10-25

    Cooling devices for use with electric submersible pump motors include a refrigerator attached to the end of the electric submersible pump motor with the evaporator heat exchanger accepting all or a portion of the heat load from the motor. The cooling device can be a self-contained bolt-on unit, so that minimal design changes to existing motors are required.

  11. Cooling devices and methods for use with electric submersible pumps

    Science.gov (United States)

    Jankowski, Todd A; Hill, Dallas D

    2014-12-02

    Cooling devices for use with electric submersible pump motors include a refrigerator attached to the end of the electric submersible pump motor with the evaporator heat exchanger accepting all or a portion of the heat load from the motor. The cooling device can be a self-contained bolt-on unit, so that minimal design changes to existing motors are required.

  12. What role do beds of submerged macrophytes play in structuring estuarine fish assemblages? Lessons from a warm-temperate South African estuary

    Science.gov (United States)

    Sheppard, Jill N.; James, Nicola C.; Whitfield, Alan K.; Cowley, Paul D.

    2011-11-01

    Habitat variability is one of the factors influencing species richness within estuarine systems, and a loss of habitat can result in a restructuring of the estuarine ichthyofaunal assemblage, particularly if these conditions persist over long time periods. The potential effects of the loss of extensive submerged macrophyte beds ( Ruppia cirrhosa and Potamogeton pectinatus) on an estuarine fish assemblage were investigated through an analysis of a long-term seine net catch dataset from the temporarily open/closed East Kleinemonde Estuary, South Africa. Catch data for a 12-year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, indicated that the loss of this habitat did not influence species richness but changes in the relative abundance of certain species were evident. A shift in dominance from vegetation-associated species to those associated with sandy environments ( e.g. members of the family Mugilidae) was observed. However, species wholly dependent on macrophytes such as the critically endangered estuarine pipefish Syngnathus watermeyeri were only recorded during years when macrophyte beds were present, while vegetation-associated species such as the sparid Rhabdosargus holubi persisted at lower levels of relative abundance. The reduced abundance of all vegetation-associated fish species during years of macrophyte senescence was probably reflective of declining food resources resulting from the loss of macrophyte beds and/or increased vulnerability to predation. Submerged beds of aquatic plants are therefore important habitats within temporarily open/closed estuaries, South Africa's dominant estuary type.

  13. Nutrient Uptake Efficiency and Growth of Two Aquatic Macrophyte ...

    African Journals Online (AJOL)

    ... to investigate the growth and nutrient uptake of two wetland plants from Lake Tana. Rhizomes of Cyperus papyrus and Phragmites karaka were grown outdoors in four parallel-aligned horizontal sub-surface flow constructed wetland (hssfcw) treatment beds. The treatment beds were irrigated with wastewater sourced from ...

  14. nutrient uptake efficiency and growth of two aquatic macrophyte

    African Journals Online (AJOL)

    Preferred Customer

    The treatment beds were irrigated with wastewater sourced from students' residence from. January 21 ... wastewater. None of these studies also investigated growth parameters and biomass production in relation to nutrient uptake of these plants. Therefore, rigorous comparison studies ..... treatment of brewery wastewater.

  15. nutrient uptake efficiency and growth of two aquatic macrophyte

    African Journals Online (AJOL)

    Preferred Customer

    plants. Therefore, rigorous comparison studies under controlled conditions are necessary to evaluate the potential of these species for wastewater treatment using ..... (2005). Nitrogen and phosphorus removal in substrate-free pilot constructed wetlands with horizontal surface flow in Uganda. Water, Air, and Soil Pollution.

  16. Aquaculture impact and treatment systems of effluents with aquatic macrophytes

    OpenAIRE

    Henry-Silva, Gustavo Gonzaga; Monteiro Camargo, Antonio Fernando [UNESP

    2008-01-01

    Aquaculture effluents are enriched by nitrogen, phosphorus and organic matter and contribute to increase eutrophication of the receiving water bodies and reduction or change in biodiversity. To reduce effluent loading is important to formulate highly digestible diets with lower nutrient levels. In addition, it is necessary to treat effluents to attend to new legislation demands and the pressure of environmentalist. This review of the aquaculture activities and its impacts on the environmental...

  17. Richness and composition of macrophyte assemblages in four Amazonian lakes - doi: 10.4025/actascibiolsci.v35i3.11602

    Directory of Open Access Journals (Sweden)

    Sidinei Magela Thomaz

    2013-08-01

    Full Text Available Aquatic macrophytes are an important component in the structure of lakes in Neotropical floodplains, for example, because they support a high diversity of invertebrates and vertebrates. In this paper, we tested whether or not the variability of macrophyte assemblages is lower in spatially close quadrats than among quadrats of different lakes. The study was carried in four lakes in a large Amazonian floodplain (Purus river, where floating meadows were investigated. A total of 49 taxa of macrophytes were found. Five species dominated and three species were rare. Taxa richness, composition and beta diversity differed more between than within lakes. Because high beta diversity was found among the lakes, they should be considered individually important for maintaining the gamma diversity of macrophytes within the Purus River floodplain, and this should be considered in plans of lake management.  

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

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, K.D.

    1996-12-31

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

  19. Effect of Hydrologic Alteration on the Community Succession of Macrophytes at Xiangyang Site, Hanjiang River, China

    Directory of Open Access Journals (Sweden)

    Na Yang

    2017-01-01

    Full Text Available With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997–2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941–2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995–2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened.

  20. Heavy metals in water, sediments and submerged macrophytes in ponds around the Dianchi Lake, China.

    Science.gov (United States)

    Wang, Zhixiu; Yao, Lu; Liu, Guihua; Liu, Wenzhi

    2014-09-01

    Through retaining runoff and pollutants such as heavy metals from surrounding landscapes, ponds around a lake play an important role in mitigating the impacts of human activities on lake ecosystems. In order to determine the potential for heavy metal accumulation of submerged macrophytes, we investigated the concentrations of 10 heavy metals (i.e., As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in water, sediments, and submerged macrophytes collected from 37 ponds around the Dianchi Lake in China. Our results showed that both water and sediments of these ponds were polluted by Pb. Water and sediments heavy metal concentrations in ponds received urban and agricultural runoff were not significantly higher than those in ponds received forest runoff. This result indicates that a large portion of heavy metals in these ponds may originate from atmospheric deposition and weathering of background soils. Positive relationships were found among heavy metal concentrations in submerged macrophytes, probably due to the coaccumulation of heavy metals. For most heavy metals, no significant relationships were found between submerged macrophytes and their water and sediment environments. The maximum concentrations of Cr, Fe and Ni in Ceratophyllum demersum were 4242, 16,429 and 2662mgkg(-1), respectively. The result suggests that C. demersum is a good candidate species for removing heavy metals from polluted aquatic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Decomposition of aquatic macrophytes from Cantá stream (Roraima, Brazil: kinetics approach Decomposição de macrófitas aquáticas do Igarapé do Cantá (Roraima, Brasil: aspectos cinéticos

    Directory of Open Access Journals (Sweden)

    Marcela Bianchessi da Cunha-Santino

    2010-06-01

    Full Text Available AIM: This study aimed at describing and comparing the kinetics of aerobic and anaerobic decomposition of Eleocharis interstincta, Nymphaea sp. and Montrichardia arborescens; METHODS: The samples of aquatic macrophytes and water were collected in the Cantá Stream (02° 49' 11" N and 60° 40' 24" W, Cantá, Roraima, Brazil. The plant material was dried and triturated and for each experimental condition (aerobic and anaerobic mineralization chambers were prepared with plant fragments and stream water. The volume of evolved gases in anaerobic mineralization was monitored during 78 days, while the oxygen consumption was measured for 121 days; RESULTS: The results of aerobic and anaerobic decomposition were fitted to first-order kinetics model. The oxygen consumption varied from 195.36 mg g-1 (DM for E. interstincta to 629.46 mg g-1 (DM for Nymphaea sp. The deoxygenation rate derived from mineralization of M. arborescens was higher (kD: 0.049 day-1, followed by E. interstincta (kD: 0.038 day-1 and Nymphaea sp. (kD: 0.027 day-1. For the anaerobic condition the evolution of gases presented two phases: the consumption and formation. According to temporal variations of mineralized carbon, the anaerobic decomposition of M. arborescens presents the higher mineralization coefficient (0.0047 day-1; followed by Nymphaea sp. (0.0035 d-1 and E. interstincta (0.0017 day-1; CONCLUSION: Based on these results we conclude that during the aerobic decomposition of these macrophytes, the Nymphaea sp. was responsible for the higher oxygen demand and M. arborescens generated the highest amounts of gases during the anaerobic mineralization. On average, the aerobic decay processes were 11-fold faster than anaerobic. Regarding to the materials fluxes in freshwater ecosystems, low rate of decomposition observed in anaerobic process when comparing to aerobic rates reflect that the sediment represent a very efficient sink of carbon in the organic matter cycling

  2. Do freshwater macrophytes influence the community structure of ammonia-oxidizing and denitrifying bacteria in the rhizospere?

    DEFF Research Database (Denmark)

    Herrmann, Martina; Schramm, Andreas

    2006-01-01

    DO FRESHWATER MACROPHYTES INFLUENCE THE COMMUNITY STRUCTURE OF AMMONIA-OXIDIZING AND DENITRIFYING BACTERIA IN THE RHIZOSPHERE? M. Herrmann, A. Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia...... to unvegetated sediment, especially with respect to the availability of oxygen, organic carbon, and inorganic nitrogen. We hypothesize that macrophyte species create specific niches for ammonia oxidizing and nitrate-reducing bacteria in their rhizosphere, leading to plant-dependant differences in abundance...... of ammonia oxidizing bacteria between the root surface, the rhizosphere and unvegetated sediment and between plant species, however, differences in the community composition among sampling sites also suggest a strong impact of the chemical properties of the sediment....

  3. Journal of Aquatic Sciences - Vol 14, No 1 (1999)

    African Journals Online (AJOL)

    Fertilization of Earth Ponds. I: Effects on Physico-Chemical Characteristics and Eutrophication of Pond Water and Soil · EMAIL FULL TEXT EMAIL FULL TEXT ... III: Effects on Benthic Macro Invertebrates and Ecological Inter-Relationship with Aquatic Macrophytes · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  4. Journal of Aquatic Sciences - Vol 29, No 2 (2014)

    African Journals Online (AJOL)

    Acute Toxicity of Delsate® Herbicide (Glyphosate) On Albumin and Blood Urea Nitrogen of African Catfish, Clarias gariepinus (Burchell, 1822) · EMAIL FULL TEXT ... Assessing Environmental Impact on Aquatic Macrophyte Species Structure in a Near Coastal Tropical River, Southeastern Nigeria · EMAIL FULL TEXT EMAIL ...

  5. 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.

  6. Associative dependence among plankton and macrophytes as pollution markers at tropical lentic environ, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Hiren B Soni

    2014-05-01

    Full Text Available The present research was undertaken at three sampling stations of Gomti catchment, Central Gujarat, India, to study dominance, interaction, and interdependence among biotic components (phytoplankton, zooplankton and aquatic macrophytes. The phytoplankton population was represented by 39 genera and 48 species belongs to family Bacillariophyceae (21 species, followed by Cyanophyceae (7, Cholorophyceae (18, and Euglenophyceae (2. In total, seven classes of zooplankton were represented by 36 genera and 39 species. Zooplankton dominance was reflected by class Ciliophora (16 species, followed by Zooflagellata, Rhizopoda and Rotifera (6 each, and Cladocera (3,and least by Copepoda and Ostracoda (1 species each. Of 16 species of aquatic macrophytes, 3 (18.75% were abundant, 4 (25% common, and 9 (56.25% were rare. The indices (Palmer, Nygaard’s, and Macrophyte index were determined to delineate the interdependent relationship among studied biotic components. Strong association was observed between Chlorophyceae and Bacillariophyceae, Ostracods and Ciliophorans, and Cladocerans and Bacillariophyceans. The detailed results of indices and interdependent associations among biotic components are discussed. The information provided herewith makes an insight for better understanding of the environmental aspects to be addressed effectively for the better protection, conservation, and management of Gomti reservoir, Gujarat, India. DOI: http://dx.doi.org/10.3126/ije.v3i2.10528 International Journal of the Environment Vol.3(2 2014: 175-191

  7. Submersible purification system for radioactive water

    Science.gov (United States)

    Abbott, Michael L.; Lewis, Donald R.

    1989-01-01

    A portable, submersible water purification system for use in a pool of water containing radioactive contamination includes a prefilter for filtering particulates from the water. A resin bed is then provided for removal of remaining dissolved, particulate, organic, and colloidal impurities from the prefiltered water. A sterilizer then sterilizes the water. The prefilter and resin bed are suitably contained and are submerged in the pool. The sterilizer is water tight and located at the surface of the pool. The water is circulated from the pool through the prefilter, resin bed, and sterilizer by suitable pump or the like. In the preferred embodiment, the resin bed is contained within a tank which stands on the bottom of the pool and to which a base mounting the prefilter and pump is attached. An inlet for the pump is provided adjacent the bottom of the pool, while the sterilizer and outlet for the system is located adjacent the top of the pool.

  8. Submersible pumping system with heat transfer mechanism

    Science.gov (United States)

    Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew

    2014-04-15

    A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.

  9. Macrophytes: ecosystem engineers in UK urban rivers

    Science.gov (United States)

    Gibbs, H.; Gurnell, A.; Heppell, K.; Spencer, K.

    2012-04-01

    Macrophytes act as ecosystem engineers within river channels in that they have the ability to cause geomorphological and ecological change. They induce reductions in flow velocity and associated sediment accumulation, and their system of underground roots and rhizomes also reinforces the accumulated sediment reducing sediment erosion and resuspension and creating habitats. As sediments, particularly finer-grained, store contaminants including metals, this engineering means that in the specific context of urban rivers where sediments are more likely to be contaminated, macrophytes trap and hold contaminated sediments creating a potentially important sink of metals. However, depending on the ability for the macrophyte to reinforce the sediment and reduce erosion and resuspension, there is the potential for the sink to turn in to a source and metals to be released in to the overlying water. This research therefore looks at the ecosystem engineering ability of common macrophytes in UK urban rivers by looking at: (i) the effect upon flow velocity and sediment accumulation of Sparganium erectum (branched bur-reed); (ii) the sediment reinforcement ability of both S. erectum, Typha latifolia (bulrush) and Phalaris arundinacea (reed canary grass); and, (iii) the storage of metals within the sediment, overlying water and the macrophytes. Research was undertaken on the River Blackwater, an urban river in Surrey, UK which has extensive macrophyte growth. Flow velocity measurements and fine sediment depths were recorded both within and outside of dense stands of S. erectum. The uprooting resistance (as an indicator of sediment reinforcement) was measured for three species: S. erectum, T. latifolia and P. arundinacea. Additionally, some preliminary sampling was undertaken of the sediment, overlying water and the macrophytes to determine metal storage. Lower flow velocities and greater volumes of fine sediment were recorded within the stands of S. erectum as opposed to the

  10. The distribution and accumulation of chromium in the water, sediment and macrophytes of Skadar lake

    Directory of Open Access Journals (Sweden)

    Kastratović Vlatko

    2016-01-01

    Full Text Available The aquatic macrophytes Phragmites australis (Cav. Trin. ex Steud., Ceratophyllum demersum L., and Lemna minor L. were used as bioindicator plant species in order to define contamination level by Cr in Skadar lake (Montenegro. Plants, water and sediments were tested for the content of Cr at six locations around Lake Skadar during four periods in 2011. The content of Cr in the examined sediment was in the range of 35.6-127 mg/kg dry weight. The largest proportion of detected Cr (50.6% was associated with the oxidizable phase in the form of organic complexes. The concentration of Cr in the studied macrophytes declined in the following order: C. demersum > P. australis > L. minor. The highest average content of Cr was detected in the leaf of C. demersum (11.4 mg/kg in April.

  11. Performance of two macrophyte species in experimental wetlands receiving variable loads of anaerobically treated municipal wastewater.

    Science.gov (United States)

    da Motta Marques, D M; Leite, G R; Giovannini, S G

    2001-01-01

    Two highly productive emergent macrophytes, Zizaniopsis bonariensis and Typha subulata were established in experimental subsurface flow, sand-based wetlands receiving anaerobically treated municipal wastewater. The hydraulic loading rate was tested in two levels, sequentially, 6.8 cm x d(-1) and 13.6 cm x d(-1), for 70 days each. In the 13.6 cm x d(-1)-loading treatment, among all monitored variables only COD, PO4-Total-P, and Turbidity were removed more efficiently by the planted beds in comparison to unplanted sand beds (PPO4-P. T. subulata beds were significantly more efficient than Zbonariensis beds for most of the variables. The highest significant differences (Pwetland beds in the lower loading condition, except for PO4-P, indicates that plants may not be needed under low loading. However aquatic macrophytes improved wetland efficiency under high loading.

  12. Abiotic controls of emergent macrophyte density in a bedrock channel - The Cahaba River, AL (USA)

    Science.gov (United States)

    Vaughn, Ryan S.; Davis, Lisa

    2015-10-01

    Research examining bedrock channels is growing. Despite this, biotic-abiotic interactions remain a topic mostly addressed in alluvial systems. This research identified hydrogeomorphic factors operating at the patch-scale (100-102 m) in bedrock shoals of the Cahaba River (AL) that help determine the distribution of the emergent aquatic macrophyte, Justicia americana. Macrophyte patch density (number of stems/m2) and percent bedrock void surface area (rock surface area/m2 occupied by joints, fractures, and potholes) were measured (n = 24 within two bedrock shoals) using stem counts and underwater photography, respectively. One-dimensional hydrologic modeling (HEC-RAS 4.1.0) was completed for a section within a shoal to examine velocity and channel depth as controlling variables for macrophyte patch density. Results from binary logistic regression analysis identified depth and velocity as good predictors of the presence or absence of Justicia americana within shoal structures (depth p = 0.001, velocity p = 0.007), which is a similar finding to previous research conducted in alluvial systems. Correlation analysis between bedrock surface void area and stem density demonstrated a statistically significant positive correlation (r = 0.665, p = 0.01), elucidating a link between abiotic-biotic processes that may well be unique to bedrock channels. These results suggest that the amount of void space present in bedrock surfaces, in addition to localized depth and velocity, helps control macrophyte patch density in bedrock shoal complexes. The utility of geomorphology in explaining patch-scale habitat heterogeneity in this study highlights geomorphology's potential to help understand macrophyte habitat heterogeneity at the reach scale, while also demonstrating its promise for mapping and understanding habitat heterogeneity at the system scale.

  13. Multielement stoichiometry of submerged macrophytes across Yunnan plateau lakes (China)

    National Research Council Canada - National Science Library

    Xing, Wei; Wu, Haoping; Shi, Qiao; Hao, Beibei; Liu, Han; Wang, Zhixiu; Liu, Guihua

    2015-01-01

    .... We predicted that tissue element composition in submerged macrophytes is affected by lake trophic level and taxonomy, and submerged macrophytes have weak stoichiometric homeostasis for all above 16 elements...

  14. Observations on marine macrophytes of the republic of Seychelles

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Jagtap, T.G.

    The distribution of macrophytes was studies from the major islands (Mahe, Praslin and La Digue) of the Seychelles Archipelago. The macrophytes were represented by 72 species of seaweeds, 8 species of mangroves and 6 species of seagrass. The dominant...

  15. Testing new submersible pumps for proper sizing and reduced costs

    Energy Technology Data Exchange (ETDEWEB)

    O' Toole, W.P.; O' Brien, J.B.

    1989-02-01

    This paper describes an ongoing program to improve overall submersible pump performance by Thums Long Beach Co., acting as contractor for the City of Long Beach, operator of the Long Beach Unit. Thums Long Beach Co. currently operates 700 submersible pump installations located on four manmade islands and one landfill pier location. The program began with spot testing of submersible pumps for Thums' use. It has evolved to 100% pump testing and the stipulation that only pumps with newly manufactured parts are acceptable. The primary goals of this program are to increase well production and to lower lifting costs. Critical to these goals is increasing the average length of run by using accurate pump-performance data to design equipment and by rejecting defective pumps before they are run. Increased production is realized from better designs. Lower lifting costs result from using more efficient pumps and a reduced frequency of pulling submersible equipment.

  16. Testing new submersible pumps for proper sizing and reduced costs

    Energy Technology Data Exchange (ETDEWEB)

    O' Toole, W.P.; O' Brien, J.B.

    1986-01-01

    This paper describes an ongoing program to improve overall submersible pump performance by Thums Long Beach Company, acting as Contractor of the City of Long Beach, Operator of the Long Beach Unit. Thums Long Beach Company currently operates 700 submersible pump installations located on four man-made islands and one land fill pier location. The program began with spot testing of submersible pumps for Thums' use. It has evolved to 100 percent pump testing and the stipulation that only pumps with newly manufactured parts are acceptable. The primary goals of this program are to increase well production and lower lifting costs. Critical to these goals is increasing the average length of run by using accurate pump performance data to design equipment and by rejecting defective pumps before they are run. Increased production is realized from better designs. Lower lifting costs result from utilizing higher efficiency pumps and a reduced frequency of pulling submersible equipment.

  17. AWWA E102-17 submersible vertical turbine pumps

    CERN Document Server

    2017-01-01

    This standard describes minimum requirements for submersible vertical turbine pumps utilizing a discharge column pipe assembly, 5 hp or larger, used in water service, including materials, design, manufacture, inspection, and testing.

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

    Science.gov (United States)

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

    1977-01-01

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

  19. Microbial Biofilm Community Variation in Flowing Habitats: Potential Utility as Bioindicators of Postmortem Submersion Intervals

    Directory of Open Access Journals (Sweden)

    Jennifer M. Lang

    2016-01-01

    Full Text Available Biofilms are a ubiquitous formation of microbial communities found on surfaces in aqueous environments. These structures have been investigated as biomonitoring indicators for stream heath, and here were used for the potential use in forensic sciences. Biofilm successional development has been proposed as a method to determine the postmortem submersion interval (PMSI of remains because there are no standard methods for estimating the PMSI and biofilms are ubiquitous in aquatic habitats. We sought to compare the development of epinecrotic (biofilms on Sus scrofa domesticus carcasses and epilithic (biofilms on unglazed ceramic tiles communities in two small streams using bacterial automated ribosomal intergenic spacer analysis. Epinecrotic communities were significantly different from epilithic communities even though environmental factors associated with each stream location also had a significant influence on biofilm structure. All communities at both locations exhibited significant succession suggesting that changing communities throughout time is a general characteristic of stream biofilm communities. The implications resulting from this work are that epinecrotic communities have distinctive shifts at the first and second weeks, and therefore the potential to be used in forensic applications by associating successional changes with submersion time to estimate a PMSI. The influence of environmental factors, however, indicates the lack of a successional pattern with the same organisms and a focus on functional diversity may be more applicable in a forensic context.

  20. The evaluation of a rake method to quantify submersed vegetation in the Upper Mississippi River

    Science.gov (United States)

    Yin, Yao; Kreiling, Rebecca M.

    2011-01-01

    A long-handled, double-headed garden rake was used to collect submersed aquatic vegetation (SAV) and compared to in-boat visual inspection to record species presence at 67 individual sites. Six rake subsamples were taken at each site and a rake density rating was given to each species collected in the subsamples. Presence at the site, frequency of occurrence in the six rake samples, and additive density rating (the sum of the six rake density ratings) were quantified for each species at each site. The validity of the indices was tested against biomass data collected by clipping all remaining vegetation from the 67 sites. In the turbid water of the Mississippi River, visual inspection of SAV from boats was ineffective with only 27% of the species detected, while raking retrieved on average 70% of the total number of submersed species in the 67 sites. Presence of species at individual sites was correlated with biomass from Stuckenia pectinata, while frequency of occurrence and additive density rating were correlated with biomass for species with greater than 21 g of total biomass from all sites. The efficiency of the rake to collect biomass varied among species; only 18% of total biomass was captured via raking the site six times. Additive density rating as an index of abundance can be used to detect temporal changes in the same water body; however, cross-species comparison is not encouraged unless the efficiency of the rake has been determined for each species being compared.

  1. Characterization of Root-Associated Methanotrophs from Three Freshwater Macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia†

    OpenAIRE

    Calhoun, A.; King, G. M.

    1998-01-01

    Root-associated methanotrophic bacteria were enriched from three common aquatic macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia. At least seven distinct taxa belonging to groups I and II were identified and presumptively assigned to the genera Methylosinus, Methylocystis, Methylomonas, and Methylococcus. Four of these strains appeared to be novel on the basis of partial 16S ribosomal DNA sequence analysis. The root-methanotroph association did not appear to be...

  2. Maximum growing depth of macrophytes in Loch Leven, Scotland, United Kingdom, in relation to historical changes in estimated phosphorus loading

    OpenAIRE

    May, Linda; Carvalho, Laurence

    2010-01-01

    Eutrophication is a common problem of shallow lakes situated in lowland areas. In their natural state, most shallow lakes would have clear water and a thriving aquatic plant community. However, eutrophication often causes turbid water, high algal productivity, and low species diversity and abundance of submerged macrophytes. In severe cases, these impacts can have serious economic consequences on local communities. A key indicator of the ecological health of lake ecosystems is the maximum gro...

  3. Macrophytic flora and vegetation of the rivers Svrljiški and Beli Timok (Eastern Serbia

    Directory of Open Access Journals (Sweden)

    Jenačković, D.

    2010-12-01

    Full Text Available Floristic and phytocoenological investigations of macrophytic vegetation of the rivers Svrljiški and Beli Timok in Eastern Serbia were performed. Analysis of the collected plants showed that the hydrophilous flora contains 26 species from 17 families and 21 genuses. Phytocoenological analysis showed 5 different associations from 3 alliances, 3 orders and 3 classis. Aquatic vegetation is represented by the associations Myriophyllo-Potametum and Potametum nodosi, moor vegetation by associations Scirpetum lacustris and Sparganietum erecti, while nitrophilous vegetation is represented by association Polygono-Bidentetum tripartitae. These associations have formed three clear vegetation belts: submerged, floating and emerged vegetation.

  4. Community structure of epiphytic algae on three different macrophytes at Acarlar floodplain forest (northern Turkey)

    Science.gov (United States)

    Tunca, Hatice; Ongun Sevindik, Tuğba; Bal, Dilek Nur; Arabaci, Sevil

    2014-07-01

    The aim of this study was to determine the species composition, biodiversity and, relative abundance of epiphytic algae and their relationship with environmental variables on three different macrophytes ( Nymphaea alba, Ceratophyllum demersum, Typha latifolia ) at Acarlar Floodplain Forest (AFF). Epiphytic algae were gathered monthly by collecting aquatic plants between November 2011 and October 2012, except in winter when there were no plants. In this study, 67 taxa on N. alba, 66 taxa on C. demersum and 66 taxa on T. latifolia were identified as epiphytic algae. The mean value of species richness was 17, that of diversity was 1.5 and that of evenness was 0.54 for epiphytic algae on N. alba, 17, 1.1, and 0.39 on C. demersum, and 18, 1.64, and 0.56 on T. latifolia, respectively. Oscillatoria sp. and Komvophoron crassum (Vozzen) Anagnostidis and Komárek were the most abundant and consistent epiphytic algal species, occurring in high abundance on all macrophytes. Results show that species composition of epiphytic algae was different, but diversity values were similar on all the macrophytes. The hydrological pulse is one of the most important factors determining the physical and chemical environment of the epiphytic algal community. However, substrate type also affected the colonization by F. capucina, O. sancta, P. catenata, and L. truncicola more than the epiphytic algal seasonality.

  5. Differences in planktonic microbial communities associated with three types of macrophyte stands in a shallow lake.

    Science.gov (United States)

    Mentes, Anikó; Szabó, Attila; Somogyi, Boglárka; Vajna, Balázs; Tugyi, Nóra; Csitári, Bianka; Vörös, Lajos; Felföldi, Tamás

    2017-11-29

    Little is known about how various substances from living and decomposing aquatic macrophytes affect the horizontal patterns of planktonic bacterial communities. Study sites were located within Lake Kolon, which is a freshwater marsh and can be characterized by open water sites and small ponds with different macrovegetation (Phragmites australis, Nymphea alba and Utricularia vulgaris). Our aim was to reveal the impact of these macrophytes on the composition of the planktonic microbial communities using comparative analysis of environmental parameters, microscopy and pyrosequencing data. Bacterial 16S rRNA gene sequences were dominated by members of phyla Proteobacteria (36-72%), Bacteroidetes (12-33%) and Actinobacteria (5-26%), but the in the anoxic sample the ratio of Chlorobi (54%) was also remarkable. In the phytoplankton community, Cryptomonas sp., Dinobryon divergens, Euglena acus and chrysoflagellates had the highest proportion. Despite the similarities in most of the measured environmental parameters, the inner ponds had different bacterial and algal communities, suggesting that the presence and quality of macrophytes directly and indirectly controlled the composition of microbial plankton. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Assessment of the Potential Biological Activity of Low Molecular Weight Metabolites of Freshwater Macrophytes with QSAR

    Directory of Open Access Journals (Sweden)

    Evgeny A. Kurashov

    2016-01-01

    Full Text Available The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial with PASS (Prediction of Activity Spectra for Substances for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L. Sm., and two species of submergent macrophyte groups, Ceratophyllum demersum L. and Potamogeton obtusifolius (Mert. et Koch, for the discovery of their ecological and pharmacological potential. The predicted probability of anti-inflammatory or antineoplastic activities above 0.8 was observed for twenty compounds. The same compounds were also characterized by high probability of antifungal and antibacterial activity. Six metabolites, namely, hexanal, pentadecanal, tetradecanoic acid, dibutyl phthalate, hexadecanoic acid, and manool, were a part of the major components of all three studied plants, indicating their high ecological significance and a certain universalism in their use by various species of water plants for the implementation of ecological and biochemical functions. This report underlines the role of identified compounds not only as important components in regulation of biochemical and metabolic pathways and processes in aquatic ecological systems, but also as potential pharmacological agents in the fight against different diseases.

  7. Development of a dynamic model for estimating the food web transfer of chemicals in small aquatic ecosystems.

    Science.gov (United States)

    Nfon, Erick; Armitage, James M; Cousins, Ian T

    2011-11-15

    A dynamic combined fate and food web model was developed to estimate the food web transfer of chemicals in small aquatic ecosystems (i.e. ponds). A novel feature of the modeling approach is that aquatic macrophytes (submerged aquatic vegetation) were included in the fate model and were also a food item in the food web model. The paper aims to investigate whether macrophytes are effective at mitigating chemical exposure and to compare the modeling approach developed here with previous modeling approaches recommended in the European Union (EU) guideline for risk assessment of pesticides. The model was used to estimate bioaccumulation of three hypothetical chemicals of varying hydrophobicity in a pond food web comprising 11 species. Three different macrophyte biomass densities were simulated in the model experiments to determine the influence of macrophytes on fate and bioaccumulation. Macrophytes were shown to have a significant effect on the fate and food web transfer of highly hydrophobic compounds with log KOW>=5. Modeled peak concentrations in biota were highest for the scenarios with the lowest macrophyte biomass density. The distribution and food web transfer of the hypothetical compound with the lowest hydrophobicity (log KOW=3) was not affected by the inclusion of aquatic macrophytes in the pond environment. For the three different hypothetical chemicals and at all macrophyte biomass densities, the maximum predicted concentrations in the top predator in the food web model were at least one order of magnitude lower than the values estimated using methods suggested in EU guidelines. The EU guideline thus provides a highly conservative estimate of risk. In our opinion, and subject to further model evaluation, a realistic assessment of dynamic food web transfer and risk can be obtained using the model presented here. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. The decomposition of estuarine macrophytes under different ...

    African Journals Online (AJOL)

    2013-04-29

    Apr 29, 2013 ... habitat destruction and over-exploitation of resources (Snow and Adams, 2007). It is critical to manage ... position of biotic communities (e.g. macrophytes) (Snow and. Adams, 2007). In estuarine systems ... sure to waves and currents, and substratum type (Pedersen and. Borum, 1996). In recent history, the ...

  9. Stream Metabolism and Aquatic Vegetation in Agriculturally Dominated Landscapes

    Science.gov (United States)

    Munn, M. D.; Bales, J. D.; Waite, I.

    2013-12-01

    Forty-six streams across 7 agricultural areas of the United States were assessed using 2-station whole-stream metabolism techniques and aquatic vegetation measurements. Land use was dominated by agriculture, ranging from 0.1 to 92 percent (mean = 44 percent), with agricultural practices ranging from low intensity pasture to high intensity irrigated agriculture. Streams represented a gradient of nutrient concentrations for TN (0.07- 9.0 mg/L) and TP (0.002-1.7 mg/L). Measures of aquatic vegetation included benthic algal biomass (chlorophyll a/m2) and percent macrophyte cover. Additional data included stream and riparian habitat and basin features. Gross primary production (GPP) ranged from 0.1 to 12 g O2/ m2/ d, with highest production occurring in macrophyte-dominated streams in Idaho and Minnesota, and benthic periphyton-dominated streams in the Ozarks (Arkansas and Missouri). GPP was positively correlated with macrophyte cover (r=0.35), but not with algal biomass. Macrophyte driven systems occurred almost exclusively in open canopy systems where canopy was less than 27 percent. Nutrient concentrations in streams were not determined to be important explanatory variables for GPP; however, modeled estimates of nitrogen and phosphorous inputs to the watershed were related to benthic algal biomass and macrophyte cover in specific agricultural areas. Habitat played a key role in GPP, benthic algal biomass, and macrophyte cover, with indicators of light (for example, canopy cover or suspended sediment), often determined to be significant explanatory variables. Approximately 75 percent of sites had negative net ecosystem production indicating heterotrophic metabolism; intensive agriculture dominated many of these streams. Nutrient management strategies in agricultural landscapes require an understanding of nutrient sources, transport mechanisms, habitat condition, and ecosystem processes in order to make sound decisions on land use practices.

  10. Average niche breadths of species in lake macrophyte communities respond to ecological gradients variably in four regions on two continents.

    Science.gov (United States)

    Alahuhta, Janne; Virtala, Antti; Hjort, Jan; Ecke, Frauke; Johnson, Lucinda B; Sass, Laura; Heino, Jani

    2017-05-01

    Different species' niche breadths in relation to ecological gradients are infrequently examined within the same study and, moreover, species niche breadths have rarely been averaged to account for variation in entire ecological communities. We investigated how average environmental niche breadths (climate, water quality and climate-water quality niches) in aquatic macrophyte communities are related to ecological gradients (latitude, longitude, altitude, species richness and lake area) among four distinct regions (Finland, Sweden and US states of Minnesota and Wisconsin) on two continents. We found that correlations between the three different measures of average niche breadths and ecological gradients varied considerably among the study regions, with average climate and average water quality niche breadth models often showing opposite trends. However, consistent patterns were also found, such as widening of average climate niche breadths and narrowing of average water quality niche breadths of aquatic macrophytes along increasing latitudinal and altitudinal gradients. This result suggests that macrophyte species are generalists in relation to temperature variations at higher latitudes and altitudes, whereas species in southern, lowland lakes are more specialised. In contrast, aquatic macrophytes growing in more southern nutrient-rich lakes were generalists in relation to water quality, while specialist species are adapted to low-productivity conditions and are found in highland lakes. Our results emphasise that species niche breadths should not be studied using only coarse-scale data of species distributions and corresponding environmental conditions, but that investigations on different kinds of niche breadths (e.g., climate vs. local niches) also require finer resolution data at broad spatial extents.

  11. Does the Lagoa do Peixe sandbar opening influence the macrophyte richness and composition in Southern Brazil wetlands?

    Directory of Open Access Journals (Sweden)

    Ana Silvia Rolon

    2013-03-01

    Full Text Available The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. This information is crucial for the management of the natural resources of the Lagoa do Peixe National Park, the unique Ramsar site in Southern Brazil. The following questions were analyzed: (1 Do richness and composition of aquatic macrophytes from Lagoa do Peixe floodplain varies temporarily according to the sandbar opening and closing? (2 Does the variation pattern of the macrophyte community changed according to the sandbar opening and closing? A set of eight sampling sites of 1ha were selected over the Lagoa do Peixe floodplain: four sites not influenced by the artificial sandbar opening and four sites influenced by this event, being two sites closer to the sandbar opening and the two sites distant to the sandbar opening. The samplings were carried out between November 2007 and October 2009. The results show that although the artificial sandbar breaching does not affect the aquatic macrophyte richness at the floodplain, it affects the dynamics of species composition. The hydrological variation related to this management can be the main factor of the continuous change in the species composition in the floodplain, especially in the Southern portion. In order to avoid impacts in the macrophyte conservation, the artificial sandbar opening should be considered carefully, since the area of study is one of the most important conservation units to wetland systems in Southern Brazil.

  12. Use of sediment CO2 by submersed rooted plants

    DEFF Research Database (Denmark)

    Winkel, Anders; Borum, Jens

    2009-01-01

    freshwater plants with different morphology and growth characteristics (Lobelia dortmanna, Lilaeopsis macloviana, Ludwigia repens, Vallisneria americana and Hydrocotyle verticillata) are able to support photosynthesis supplied by uptake of CO2 from the sediment. Methods: Gross photosynthesis was measured......Background and Aims: Submersed plants have different strategies to overcome inorganic carbon limitation. It is generally assumed that only small rosette species (isoetids) are able to utilize the high sediment CO2 availability. The present study examined to what extent five species of submersed......, the shoot to root ratio on an areal basis was the single factor best explaining variability in the importance of sediment CO2. For Ludwigia, diffusion barriers limited uptake or transport from roots to stems and transport from stems to leaves. Conclusions: Submersed plants other than isoetids can utilize...

  13. Global ecological impacts of invasive species in aquatic ecosystems.

    Science.gov (United States)

    Gallardo, Belinda; Clavero, Miguel; Sánchez, Marta I; Vilà, Montserrat

    2016-01-01

    The introduction of invasive species, which often differ functionally from the components of the recipient community, generates ecological impacts that propagate along the food web. This review aims to determine how consistent the impacts of aquatic invasions are across taxa and habitats. To that end, we present a global meta-analysis from 151 publications (733 cases), covering a wide range of invaders (primary producers, filter collectors, omnivores and predators), resident aquatic community components (macrophytes, phytoplankton, zooplankton, benthic invertebrates and fish) and habitats (rivers, lakes and estuaries). Our synthesis suggests a strong negative influence of invasive species on the abundance of aquatic communities, particularly macrophytes, zooplankton and fish. In contrast, there was no general evidence for a decrease in species diversity in invaded habitats, suggesting a time lag between rapid abundance changes and local extinctions. Invaded habitats showed increased water turbidity, nitrogen and organic matter concentration, which are related to the capacity of invaders to transform habitats and increase eutrophication. The expansion of invasive macrophytes caused the largest decrease in fish abundance, the filtering activity of filter collectors depleted planktonic communities, omnivores (including both facultative and obligate herbivores) were responsible for the greatest decline in macrophyte abundance, and benthic invertebrates were most negatively affected by the introduction of new predators. These impacts were relatively consistent across habitats and experimental approaches. Based on our results, we propose a framework of positive and negative links between invasive species at four trophic positions and the five different components of recipient communities. This framework incorporates both direct biotic interactions (predation, competition, grazing) and indirect changes to the water physicochemical conditions mediated by invaders (habitat

  14. 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.

  15. Predicting species cover of marine macrophyte and invertebrate species combining hyperspectral remote sensing, machine learning and regression techniques.

    Directory of Open Access Journals (Sweden)

    Jonne Kotta

    Full Text Available In order to understand biotic patterns and their changes in nature there is an obvious need for high-quality seamless measurements of such patterns. If remote sensing methods have been applied with reasonable success in terrestrial environment, their use in aquatic ecosystems still remained challenging. In the present study we combined hyperspectral remote sensing and boosted regression tree modelling (BTR, an ensemble method for statistical techniques and machine learning, in order to test their applicability in predicting macrophyte and invertebrate species cover in the optically complex seawater of the Baltic Sea. The BRT technique combined with remote sensing and traditional spatial modelling succeeded in identifying, constructing and testing functionality of abiotic environmental predictors on the coverage of benthic macrophyte and invertebrate species. Our models easily predicted a large quantity of macrophyte and invertebrate species cover and recaptured multitude of interactions between environment and biota indicating a strong potential of the method in the modelling of aquatic species in the large variety of ecosystems.

  16. Aquatic plants

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  17. Submersible telemetry system downhole unit model for the petroleum industry

    Science.gov (United States)

    Rubtsova, O. O.; Trofimova, E. S.; Ishchenko, A. V.; Cherepanov, A. N.; Danilov, V. Yu.

    2017-09-01

    This article addresses the issue of increasing requirements for the oil industry: the need to develop new wells and control their profitability. The device under consideration (a submersible telemetry system that is capable of measuring well parameters and transferring them via the communication line to the ground based control system) will allow to avoid downtime when it is extracted for indicators check.

  18. Effects of cold stratification, sulphuric acid, submersion in hot and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... This study was carried out to determine which pre-treatments should be preferred to overcome dormancy problems of Colutea armena seeds which were collected from three different provenances. Pre-treatments applied to the seeds were submersion in concentrated (98%) sulphuric acid for 30 min,.

  19. Effects of cold stratification, sulphuric acid, submersion in hot and ...

    African Journals Online (AJOL)

    Effects of cold stratification, sulphuric acid, submersion in hot and tap water pretreatments in the greenhouse and open field conditions on germination of bladder-Senna ... This study was carried out to determine which pre-treatments should be preferred to overcome dormancy problems of Colutea armena seeds which were ...

  20. Submersible microbial fuel cell for electricity production from sewage sludge

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit

    2010-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treatment of sewage sludge and simultaneous generate electricity. Stable power generation (145±5 mW/m2) was produced continuously from raw sewage sludge for 5.5 days. The corresponding total chemical oxygen demand (TCOD) removal efficiency...

  1. THE INFLUENCE OF SUBMERGED MACROPHYTES ON SEDIMENTARY DIATOM ASSEMBLAGES(1).

    Science.gov (United States)

    Vermaire, Jesse C; Prairie, Yves T; Gregory-Eaves, Irene

    2011-12-01

    Submerged macrophytes are a central component of lake ecosystems; however, little is known regarding their long-term response to environmental change. We have examined the potential of diatoms as indicators of past macrophyte biomass. We first sampled periphyton to determine whether habitat was a predictor of diatom assemblage. We then sampled 41 lakes in Quebec, Canada, to evaluate whether whole-lake submerged macrophyte biomass (BiomEpiV) influenced surface sediment diatom assemblages. A multivariate regression tree (MRT) was used to construct a semiquantitative model to reconstruct past macrophyte biomass. We determined that periphytic diatom assemblages on macrophytes were significantly different from those on wood and rocks (ANOSIM R = 0.63, P macrophyte, nutrient-limited lakes (BiomEpiV ≥525 μg · L(-1) ; total phosphorus [TP] macrophyte, nutrient-limited lakes (BiomEpiV eutrophic lakes (TP ≥35 μg · L(-1) ; six lakes). A semiquantitative model correctly predicted the MRT group of the lake 71% of the time (P macrophytes have a significant influence on diatom community structure and that sedimentary diatom assemblages can be used to infer past macrophyte abundance. © 2011 Phycological Society of America.

  2. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms and zooplankton (rotifers and crustaceans in small field and forest water bodies.

    Directory of Open Access Journals (Sweden)

    Sofia Celewicz-Gołdyn

    Full Text Available Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla were significantly related to elodeids. However, pelagic species (e.g. bosminids preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds and natural catchment (26 forest ponds, significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state

  3. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms) and zooplankton (rotifers and crustaceans) in small field and forest water bodies.

    Science.gov (United States)

    Celewicz-Gołdyn, Sofia; Kuczyńska-Kippen, Natalia

    2017-01-01

    Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis) and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla) were significantly related to elodeids. However, pelagic species (e.g. bosminids) preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds) and natural catchment (26 forest ponds), significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP) and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum) and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni) abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state of small

  4. Review of alien marine macrophytes in Tunisia

    Directory of Open Access Journals (Sweden)

    Y. R. SGHAIER

    2015-01-01

    Full Text Available In the present study, the list of alien marine macrophytes introduced into Tunisia was updated in the light of available data and new observations. A total of 27 alien marine macrophytes have been recorded so far from Tunisia: 18 Rhodophyta, 3 Ochrophyta, 5 Chlorophyta and 1 Magnoliophyta. For each species, the locality (-ies, the year (or period and the source of the first observation in Tunisia are given. The distribution and the status (casual, cryptogenic, established or questionable of species in Tunisia were evaluated and, where appropriate, discussed. Among them, Hypnea cornuta is reported for the first time from Tunisia. Fourteen alien marine macrophytes are established, whereas seven cryptogenic and two casual species require further investigation. Eleven species are considered as invasive or potentially invasive in the Mediterranean Sea: Acrothamnion preissii, Asparagopsis armata, A. taxiformis Indo-Pacific lineage, Hypnea cornuta, Lophocladia lallemandii, Womersleyella setacea, Caulerpa chemnitzia, C. cylindracea, C. taxifolia, Codium fragile subsp. fragile and Halophila stipulacea. Finally, the case of four questionable species is also discussed.

  5. Monitoring aquatic environments with autonomous systems

    DEFF Research Database (Denmark)

    Christensen, Jesper Philip Aagaard

    High frequency measurements from autonomous sensors have become a widely used tool among aquatic scientists. This report focus primarily on the use of ecosystem metabolism based on high frequency oxygen measurements and relates the calculations to spatial variation, biomass of the primary producers...... and in shallow systems the macrophytes can completely dominate primary production. This was despite the fact that the plants in the studied system were light-saturated most of the light hours and occasionally carbon limited. It was also shown that the GPP and the total phytoplankton biomass in a nutrient...

  6. Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

    Directory of Open Access Journals (Sweden)

    LH. Sipaúba-Tavares

    Full Text Available Plankton communities and macrofauna associated to aquatic macrophyte stands in a shallow water-supply reservoir (21°14′09″S; 48°18′38″W on an aquaculture farm were compared to evaluate the relationship between organism densities and some abiotic features of the reservoir. Water and communities associated were sampled at two sites, one in an area with the predominance of Eichhornia azurea (Sw. Kunth and the other with the predominance of Salvinia auriculata Aublet. Communities associated with macrophytes were sampled with floating quadrants (0.5 m2; the macrophytes were washed and plankton and macrofauna were fixated with 4% formalin and 1% lugol iodine; the specimens were then identified and counted. Plankton and macrofauna communities associated with S. auriculata and E. azurea had a similar diversity of species but different (p<0.05 in the abundance of associated organisms. Eichhornia azurea had the highest contents in dry and wet weight, total phosphorus, total nitrogen and organic matter. Planktonic algae were directly correlated with biomass of E. azurea. The taxa with highest densities were Rotifera and Zygnematophyceae. Results showed that the environmental variables associated with macrophytes presence in the shallow reservoir is a strong predictor of favourable conditions to maintain great diversity plankton community and macrofauna associated with plants. The role of macrophytes is important for not only stabilising the clear-water state and maintaining high diversity of organisms associated, but also it seems to be a good alternative to maintaining desirable water-supply quality for aquaculture farms.

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

    Science.gov (United States)

    1979-10-01

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

  8. Macrophyte communities of European streams with altered physical habitat

    NARCIS (Netherlands)

    O'Hare, M.; Baattrup-Pedersen, A.; Nijboer, R.C.; Szoszkiewicz, K.; Ferreira, T.

    2006-01-01

    The impact of altering hydro-morphology on three macrophyte community types was investigated at 107 European stream sites. Sites were surveyed using standard macrophyte and habitat survey techniques (Mean Trophic Rank Methodology and River Habitat Survey respectively). Principal Components Analysis

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    N Rubén Cúneo

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

  11. Issues in offshore platform research - Part 1: Semi-submersibles

    Science.gov (United States)

    Sharma, R.; Kim, Tae-Wan; Sha, O. P.; Misra, S. C.

    2010-09-01

    Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

  12. Issues in offshore platform research - Part 1: Semi-submersibles

    Directory of Open Access Journals (Sweden)

    R. Sharma

    2010-09-01

    Full Text Available Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

  13. Detritus quality controls macrophyte decomposition under different nutrient concentrations in a eutrophic shallow lake, North China.

    Directory of Open Access Journals (Sweden)

    Xia Li

    Full Text Available Macrophyte decomposition is important for carbon and nutrient cycling in lake ecosystems. Currently, little is known about how this process responds to detritus quality and water nutrient conditions in eutrophic shallow lakes in which incomplete decomposition of detritus accelerates the lake terrestrialization process. In this study, we investigated the effects of detritus quality and water nutrient concentrations on macrophyte decomposition in Lake Baiyangdian, China, by analyzing the decomposition of three major aquatic plants at three sites with different pollution intensities (low, medium, and high pollution sites. Detritus quality refers to detritus nutrient contents as well as C:N, C:P, and N:P mass ratios in this study. Effects of detritus mixtures were tested by combining pairs of representative macrophytes at ratios of 75:25, 50:50 and 25:75 (mass basis. The results indicate that the influence of species types on decomposition was stronger than that of site conditions. Correlation analysis showed that mass losses at the end of the experimental period were significantly controlled by initial detritus chemistry, especially by the initial phosphorus (P content, carbon to nitrogen (C:N, and carbon to phosphorus (C:P mass ratios in the detritus. The decomposition processes were also influenced by water chemistry. The NO(3-N and NH(4-N concentrations in the lake water retarded detritus mass loss at the low and high pollution sites, respectively. Net P mineralization in detritus was observed at all sites and detritus P release at the high pollution site was slower than at the other two sites. Nonadditive effects of mixtures tended to be species specific due to the different nutrient contents in each species. Results suggest that the nonadditive effects varied significantly among different sites, indicating that interactions between the detritus quality in species mixtures and site water chemistry may be another driver controlling decomposition

  14. Detritus quality controls macrophyte decomposition under different nutrient concentrations in a eutrophic shallow lake, North China.

    Science.gov (United States)

    Li, Xia; Cui, Baoshan; Yang, Qichun; Tian, Hanqin; Lan, Yan; Wang, Tingting; Han, Zhen

    2012-01-01

    Macrophyte decomposition is important for carbon and nutrient cycling in lake ecosystems. Currently, little is known about how this process responds to detritus quality and water nutrient conditions in eutrophic shallow lakes in which incomplete decomposition of detritus accelerates the lake terrestrialization process. In this study, we investigated the effects of detritus quality and water nutrient concentrations on macrophyte decomposition in Lake Baiyangdian, China, by analyzing the decomposition of three major aquatic plants at three sites with different pollution intensities (low, medium, and high pollution sites). Detritus quality refers to detritus nutrient contents as well as C:N, C:P, and N:P mass ratios in this study. Effects of detritus mixtures were tested by combining pairs of representative macrophytes at ratios of 75:25, 50:50 and 25:75 (mass basis). The results indicate that the influence of species types on decomposition was stronger than that of site conditions. Correlation analysis showed that mass losses at the end of the experimental period were significantly controlled by initial detritus chemistry, especially by the initial phosphorus (P) content, carbon to nitrogen (C:N), and carbon to phosphorus (C:P) mass ratios in the detritus. The decomposition processes were also influenced by water chemistry. The NO(3)-N and NH(4)-N concentrations in the lake water retarded detritus mass loss at the low and high pollution sites, respectively. Net P mineralization in detritus was observed at all sites and detritus P release at the high pollution site was slower than at the other two sites. Nonadditive effects of mixtures tended to be species specific due to the different nutrient contents in each species. Results suggest that the nonadditive effects varied significantly among different sites, indicating that interactions between the detritus quality in species mixtures and site water chemistry may be another driver controlling decomposition in eutrophic

  15. An optimisation approach for shallow lake restoration through macrophyte management

    Science.gov (United States)

    Xu, Z. H.; Yin, X. A.; Yang, Z. F.

    2014-06-01

    Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of a lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality), rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area) and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.

  16. Cellulase activity and dissolved organic carbon release from lignocellulose macrophyte-derived in four trophic conditions

    Directory of Open Access Journals (Sweden)

    Flávia Bottino

    2016-06-01

    Full Text Available Abstract Considering the importance of lignocellulose macrophyte-derived for the energy flux in aquatic ecosystems and the nutrient concentrations as a function of force which influences the decomposition process, this study aims to relate the enzymatic activity and lignocellulose hydrolysis in different trophic statuses. Water samples and two macrophyte species were collected from the littoral zone of a subtropical Brazilian Reservoir. A lignocellulosic matrix was obtained using aqueous extraction of dried plant material (≈40 °C. Incubations for decomposition of the lignocellulosic matrix were prepared using lignocelluloses, inoculums and filtered water simulating different trophic statuses with the same N:P ratio. The particulate organic carbon and dissolved organic carbon (POC and DOC, respectively were quantified, the cellulase enzymatic activity was measured by releasing reducing sugars and immobilized carbon was analyzed by filtration. During the cellulose degradation indicated by the cellulase activity, the dissolved organic carbon daily rate and enzyme activity increased. It was related to a fast hydrolysable fraction of cellulose that contributed to short-term carbon immobilization (ca. 10 days. After approximately 20 days, the dissolved organic carbon and enzyme activity were inversely correlated suggesting that the respiration of microorganisms was responsible for carbon mineralization. Cellulose was an important resource in low nutrient conditions (oligotrophic. However, the detritus quality played a major role in the lignocelluloses degradation (i.e., enzyme activity and carbon release.

  17. Small-stature emergent macrophytes and crepuscular sprinkler disturbance reduce mosquito abundance in wetland mesocosms.

    Science.gov (United States)

    Popko, David A; Walton, William E

    2013-12-01

    The impact of emergent macrophyte species and crepuscular sprinkler disturbance on mosquito abundance over a 2-year period was measured in wetland mesocosms. Mosquito oviposition and abundance of immature mosquitoes and aquatic invertebrates were monitored in monotypic plots of small-stature (height of mature stands Schoenoplectus maritimus) and large-stature (height of mature stands > 2 m) California bulrush (Schoenoplectus californicus) without or with daily sprinkler showers to deter mosquito egg laying. Relative to wetlands without operational sprinklers, oviposition by culicine mosquitoes was reduced by > 99% and immature mosquito abundance was reduced by > 90% by crepuscular sprinkler applications. Mosquito abundance or distribution in wetlands did not differ between the two bulrush species subjected to the sprinkler treatment. Alkali bulrush wetlands without daily sprinkler treatments contained more egg rafts but significantly fewer mosquito larvae than did California bulrush wetlands. Predaceous damselfly naiads were 3-5 times more abundant in alkali bulrush than in California bulrush. Stem density, rate of spread, and autumnal mortality of alkali bulrush were higher than for California bulrush. Replacement of large emergent macrophytes by smaller species may enhance the efficacy of integrated mosquito management programs to reduce mosquito-transmitted disease cycles associated with multipurpose constructed wetlands used worldwide for water reclamation and habitat restoration. © 2013 The Society for Vector Ecology.

  18. Comparison of Three Biomass Sampling Techniques on Submersed Aquatic Plants in a Northern Tier Lake

    Science.gov (United States)

    2010-07-01

    milfoil (M. sibiricum Komarov, p= 0.8393), najas ( Najas spp.,p=0.1068), broadleaf pondweed (Potamogeton amplifolius Tuck, p=0.8779), curlyleaf pondweed...0.6490), Eurasian milfoil (p=0.1462), northern milfoil (p= 0.6053), najas (p=0.4793), broadleaf pondweed (p=0.6053), curlyleaf pondweed (p=0.0732...collected by the PVC-core sampler. These included coontail (p=0.000), chara (p=0.0219), American elodea (p=0.0061), forked duckweed (p=0.0000), najas (p

  19. Carbon-Flow-Based Modeling of Ecophysiological Processes and Biomass Dynamics of Submersed Aquatic Plants

    Science.gov (United States)

    2007-09-01

    Publications. Voss, E. 1972. Michigan Flora. Part I – Gymnosperms and monocots. Bloomfield Hills, Michigan: Cranbrook Institute of Science, 488 pp...SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON a. REPORT UNCLASSIFIED b. ABSTRACT

  20. Macroinvertebrate communities associated with macrophyte habitats in a tropical man-made lake (Lake Taabo, Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Kouamé M. K.

    2011-02-01

    Full Text Available An ecological study was done on Lake Taabo with the main objective of characterising macroinvertebrate communities associated with the microhabitats created mainly by Eichhornia crassipes and other littoral native macrophytes. We sampled organisms in patches of those aquatic macrophytes. Also, some abiotic variables (temperature, transparency, turbidity, pH, TDS, conductivity, dissolved oxygen, NH$_{4}^{+}$+4, NO$_{3}^{-}$−3, NO$_{2}^{-}$−2, PO$_{4}^{3-}$3−4 and SiO$_{2}^{-}$−2 were measured. Overall, forty-three taxa of macroinvertebrates were identified. Ten of them were exclusively associated with water hyacinth while five were only associated with littoral macrophytes. Macroinvertebrate taxa with some of the highest family richness were Gastropoda, Coleoptera, Heteroptera, Odonata and Diptera. The taxon with highest density in both microhabitats was Chironomidae. Although higher values of taxonomic richness (Rs, the Shannon index (H′ and evenness (J were obtained with the water hyacinth habitat, significant differences between the two microhabitats were not observed. Canonical Correspondence Analysis revealed that samples of E. crassipes collected in the dry season were characterised by Gastropoda and Odonata, as well as higher values of transparency and ammonia-nitrogen. Baetidae, Hydrophilidae, Chironomidae, Ceratopogonidae, Coenagrionidae, Naucoridae and Ostracoda were most abundant in both E. crassipes and littoral macrophyte habitats during the rainy season. This season was characterised by higher levels of nitrates and conductivity.

  1. Application of hyperspectral techniques to multispectral data: spectral mixture analysis (SMA) in mapping of emergent macrophytes in a water-hyacinth-infested area

    Science.gov (United States)

    Idawo, Cuthbert; Jajah, Munzer; Laneve, Giovanni

    2004-02-01

    Water hyacinth (Eicchornia crassipes (Mart.) Solms) is an invasive aquatic macrophyte that has infested the lake Victoria, East Africa, since the late 1980s. It has been associated with major negative economic and ecological impact of this important water resource in East Africa. Remote sensing technology has significant potential in mapping this fast growing floating weed, in a mostly inaccessible area for field measurements. Our study site is the Winam Gulf, on the Kenyan part of the Lake, which has had the highest reported infestation in recent years. The paper describes a study to evaluate the ability of ETM+ multispectral imagery in mapping water hyacinth and associated macrophytes in the hyacinth infested Winam Gulf. By applying hyperspectral techniques on multispectral data, a spectral mixture analysis was undertaken using image-derived endmembers. The study was also an evaluation of an alternative way of acquiring emergent macrophytic endmembers in cases where limitations like lack of hyperspectral data, spectrometric measurements and spectral libraries exist. The results demonstrate that whereas it is possible to discriminate and map the different spectral constituents, a spectral library of the endmembers under investigation would be required for positive identification, especially for macrophytes that are closely related spectrally, fast growing, have varying concentrations (density) spatially, and are non-static in nature.

  2. Diversity and biomass of native macrophytes are negatively related to dominance of an invasive Poaceae in Brazilian sub-tropical streams

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Gonçalves Fernandes

    2013-06-01

    Full Text Available Besides exacerbated exploitation, pollution, flow alteration and habitats degradation, freshwater biodiversity is also threatened by biological invasions. This paper addresses how native aquatic macrophyte communities are affected by the non-native species Urochloa arrecta, a current successful invader in Brazilian freshwater systems. We compared the native macrophytes colonizing patches dominated and non-dominated by this invader species. We surveyed eight streams in Northwest Paraná State (Brazil. In each stream, we recorded native macrophytes' richness and biomass in sites where U. arrecta was dominant and in sites where it was not dominant or absent. No native species were found in seven, out of the eight investigated sites where U. arrecta was dominant. Thus, we found higher native species richness, Shannon index and native biomass values in sites without dominance of U. arrecta than in sites dominated by this invader. Although difficult to conclude about causes of such differences, we infer that the elevated biomass production by this grass might be the primary reason for alterations in invaded environments and for the consequent impacts on macrophytes' native communities. However, biotic resistance offered by native richer sites could be an alternative explanation for our results. To mitigate potential impacts and to prevent future environmental perturbations, we propose mechanical removal of the invasive species and maintenance or restoration of riparian vegetation, for freshwater ecosystems have vital importance for the maintenance of ecological services and biodiversity and should be preserved.

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

    Directory of Open Access Journals (Sweden)

    Aurélio R. Meneses

    2013-09-01

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

  4. Watercress and amphipods Potential chemical defense in a spring stream macrophyte.

    Science.gov (United States)

    Newman, R M; Kerfoot, W C; Hanscom, Z

    1990-01-01

    We investigated the potential role of defensive chemicals in the avoidance of watercress (Nasturtium officinale) by the cooccurring amphipod,Gammarus pseudolimnaeus at two spring brooks: Carp Creek, Michigan and Squabble Brook, Connecticut. We conducted observations and laboratory experiments on the consumption of watercress, the toxicity of damaged (frozen) watercress, and the toxicity of damage-released secondary chemicals. Field-collected yellowed watercress typically lacked the bite and odor characteristic of green watercress and was consumed byG. pseudolimnaeus. G. pseudolimnaeus strongly preferred yellowed watercress to green watercress despite the higher nitrogen content of the latter (2.7 vs 5.4%), and usually consumed five times more yellowed watercress (>50% of yellowed leaf area vs. officinale and may contribute to defense from herbivory by aquatic crustaceans. This system may be just one of many examples of the use of defensive chemicals by stream and lake macrophytes.

  5. EUTROPHICATION OF WATER RESERVOIRS AND ROLE OF MACROPHYTES IN THIS PROCESS

    Directory of Open Access Journals (Sweden)

    Joanna Jadwiga Sender

    2017-06-01

    Full Text Available The paper presents the problem related with the process of eutrophication, with special emphasis on dam reservoirs. Eutrophication is a global process, threatening the water ecosystem on every continent. It often leads to their degradation. Particularly vulnerable to eutrophication are artificial reservoirs which are dam reservoirs. This paper describes the mechanisms of eutrophication. We also pointed to the importance of aquatic plants in the process of water purification, as well as the possibility of multilateral use. Recently, in the world and in Poland there is a tendency to pay attention to the natural or semi-natural method of water purification (including constructed wetland. On the one hand, the presence of macrophytes in water bodies is a guarantor of good ecological status, on the other hand, the undeniable aesthetic value.

  6. Assessment of the abnormal growth of floating macrophytes in Winam Gulf (Kenya) by using MODIS imagery time series

    Science.gov (United States)

    Fusilli, L.; Collins, M. O.; Laneve, G.; Palombo, A.; Pignatti, S.; Santini, F.

    2013-02-01

    The objective of this research study is to assess the capability of time-series of MODIS imagery to provide information suitable for enhancing the understanding of the temporal cycles shown by the abnormal growth of the floating macrophytes in order to support monitoring and management action of Lake Victoria water resources. The proliferation of invasive plants and aquatic weeds is of growing concern. Starting from 1989, Lake Victoria has been interested by the high infestation of water hyacinth with significant socio-economic impact on riparian populations. In this paper, we describe an approach based on the time-series of MODIS to derive the temporal behaviour, the abundance and distribution of the floating macrophytes in the Winam Gulf (Kenyan portion of the Lake Victoria) and its possible links to the concentrations of the main water constituencies. To this end, we consider the NDVI values computed from the MODIS imagery time-series from 2000 to 2009 to identify the floating macrophytes cover and an appropriate bio-optical model to retrieve, by means of an inverse procedure, the concentrations of chlorophyll a, coloured dissolved organic matter and total suspended solid. The maps of the floating vegetation based on the NDVI values allow us to assess the spatial and temporal dynamics of the weeds with high time resolution. A floating vegetation index (FVI) has been introduced for describing the weeds pollution level. The results of the analysis show a consistent temporal relation between the water constituent concentrations within the Winam Gulf and the FVI, especially in the proximity of the greatest proliferation of floating vegetation in the last 10 years that occurred between the second half of 2006 and the first half of 2007.The adopted approach will be useful to implement an automatic system for monitoring and predicting the floating macrophytes proliferation in Lake Victoria.

  7. 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.

  8. Selection of wild macrophytes for use in constructed wetlands for phytoremediation of contaminant mixtures.

    Science.gov (United States)

    Guittonny-Philippe, Anna; Petit, Marie-Eléonore; Masotti, Véronique; Monnier, Yogan; Malleret, Laure; Coulomb, Bruno; Combroux, Isabelle; Baumberger, Teddy; Viglione, Julien; Laffont-Schwob, Isabelle

    2015-01-01

    Constructed wetlands (CWs) offer an alternative to traditional industrial wastewater treatment systems that has been proved to be efficient, cost-effective and environmentally friendly. Most of the time, CWs are planted with proliferative species such as Phragmites australis or with plants originating from nurseries, both representing a risk for the natural biodiversity conservation of aquatic ecosystems located downstream of the CWs. For the removal of metals and organic pollutant mixtures present in industrial effluents, it is necessary to select tolerant plant species that are able to produce a high aboveground biomass and to develop a healthy belowground system. Wild plant species growing in aquatic bodies at industrial outfalls could constitute suitable tolerant species to use in CWs for industrial effluent treatment. To test this hypothesis, we assessed, under laboratory conditions (using an experimental design), the tolerance to mixtures of metals (Al, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Sn, Zn) or/and organic pollutants (THC, PHE, PYR, LAS) of five European sub-cosmopolitan native macrophytes (Alisma lanceolatum, Carex cuprina, Epilobium hirsutum, Iris pseudacorus and Juncus inflexus) that had been collected in a polluted Mediterranean wetland, after a field study (crossing ecological relevés and analyses of contaminant concentrations in water and sediments). Our results demonstrated that research on phytoremediation of industrial effluents should focus much more on the use of native macrophytes growing at short distances from industrial discharges (such as C. cuprina in this study), and that root/shoot ratio, aerial height and proportion of green leaves are good and cost-effective indicators of plant tolerance to metals and organic pollutant mixtures in laboratory studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Species pool versus site limitations of macrophytes in urban waters

    DEFF Research Database (Denmark)

    Vermonden, K.; Leuven, R.S.E.W.; van der Velde, G.

    2010-01-01

    Biodiversity in urban areas is affected by a multitude of stressors. In addition to physico-chemical stress factors, the native regional species pool can be greatly reduced in highly urbanized landscapes due to area loss and fragmentation. In this study, we investigated how macrophyte composition...... and diversity in urban water systems are limited by the regional species pool and local environmental conditions. Canonical correspondence analysis of the macrophyte species composition revealed that urban and semi-natural water systems differed and differences could be related to local abiotic variables...... such as pH and iron concentrations. Macrophytes in the semi-natural area were typical for slightly acid and oligotrophic conditions. In urban water systems, exotic species characteristic of eutrophic conditions were present. In the semi-natural areas, the number of macrophyte species exceeded the number...

  10. Larvicidal activity of some marine macrophytes against Artemia salina

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    Petroleum ether (PE) and chloroform (C) soluble fractions of methanolic extracts of nine different macrophytes viz. mangroves (Derris heptaphyla, Salvadora persica, Sonneratia caseolaris and Clerodendrum inerme), seaweeds (Acanthophora muscoides...

  11. Use of sediment CO2 by submersed rooted plants.

    Science.gov (United States)

    Winkel, Anders; Borum, Jens

    2009-05-01

    Submersed plants have different strategies to overcome inorganic carbon limitation. It is generally assumed that only small rosette species (isoetids) are able to utilize the high sediment CO(2) availability. The present study examined to what extent five species of submersed freshwater plants with different morphology and growth characteristics (Lobelia dortmanna, Lilaeopsis macloviana, Ludwigia repens, Vallisneria americana and Hydrocotyle verticillata) are able to support photosynthesis supplied by uptake of CO(2) from the sediment. Gross photosynthesis was measured in two-compartment split chambers with low inorganic carbon availability in leaf compartments and variable CO(2) availability (0 to >8 mmol L(-1)) in root compartments. Photosynthetic rates based on root-supplied CO(2) were compared with maximum rates obtained at saturating leaf CO(2) availability, and (14)C experiments were conducted for two species to localize bottlenecks for utilization of sediment CO(2). All species except Hydrocotyle were able to use sediment CO(2), however, with variable efficiency, and with the isoetid, Lobelia, as clearly the most effective and the elodeid, Ludwigia, as the least efficient. At a water column CO(2) concentration in equilibrium with air, Lobelia, Lilaeopsis and Vallisneria covered >75% of their CO(2) requirements by sediment uptake, and sediment CO(2) contributed substantially to photosynthesis at water CO(2) concentrations up to 1000 micromol L(-1). For all species except Ludwigia, the shoot to root ratio on an areal basis was the single factor best explaining variability in the importance of sediment CO(2). For Ludwigia, diffusion barriers limited uptake or transport from roots to stems and transport from stems to leaves. Submersed plants other than isoetids can utilize sediment CO(2), and small and medium sized elodeids with high root to shoot area in particular may benefit substantially from uptake of sediment CO(2) in low alkaline lakes.

  12. Optimization of operating costs in managing electrical submersible pumping systems

    Science.gov (United States)

    Kozlov, V. V.; Speranskaya, N. I.

    2017-10-01

    Using the methods of analysis, the task of minimizing the specific operating costs for oil production by submersible ESP units was formalized. The analysis of the multidimensional parameter space of the “ESP-well” system made it possible to isolate the vector of controlled parameters, determine the range of admissible parameters, and also to simplify the problem of finding an extremum up to the three-dimensional case. An application of the method of Lagrange multipliers to the solution of the problem is considered.

  13. Sodium dopants in helium clusters: Structure, equilibrium and submersion kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, F. [Laboratoire Interdisciplinaire de Physique, Rue de La Piscine, Campus Saint Martin d’Hères, 38000 Grenoble (France)

    2015-12-31

    Alkali impurities bind to helium nanodroplets very differently depending on their size and charge state, large neutral or charged dopants being wetted by the droplet whereas small neutral impurities prefer to reside aside. Using various computational modeling tools such as quantum Monte Carlo and path-integral molecular dynamics simulations, we have revisited some aspects of the physical chemistry of helium droplets interacting with sodium impurities, including the onset of snowball formation in presence of many-body polarization forces, the transition from non-wetted to wetted behavior in larger sodium clusters, and the kinetics of submersion of small dopants after sudden ionization.

  14. Uptake, translocation and elimination in sediment-rooted macrophytes: A model-supported analysis of whole sediment toxicity test data

    NARCIS (Netherlands)

    Diepens, N.J.; Arts, G.H.P.; Focks, A.; Koelmans, A.A.

    2014-01-01

    Understanding bioaccumulation in sediment-rooted macrophytes is crucial for the development of sediment toxicity tests using macrophytes. Here we explore bioaccumulation in sediment-rooted macrophytes by tracking and modelling chemical flows of chlorpyrifos, linuron, and six PCBs in

  15. Bioactivity effect of two macrophyte extracts on growth performance of two bloom-forming cyanophytes

    Directory of Open Access Journals (Sweden)

    M.G. Ghobrial

    2015-01-01

    Full Text Available Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy or detrimental (negative allelopathy effects on the target organisms. The current research aims at using selected brackish water adapted submerged aquatic macrophytes allelopathy to combat bloom-forming cyanophytes, in laboratory bioassay experiments. Dry matters of macrophytes were extracted in solvents and the initial cyanophytes inoculum, derived from unialgal culture media, was used. Therefore, aqueous extracts with 50% and 100% acetone and ethanol solvents of two freshwater macrophytes; Potamogeton pectinatus and Ceratophyllum demersum were used to test their growth performance exhibited on two bloom-forming cyanophytes, Microcystis aeruginosa and Oscillatoria tenuis. The results revealed insignificant difference between the overall total average growth performance at treatment with 50% and 100% Ceratophyllum acetone extracts expressed by optical density (OD as well as chlorophyll a (chl a. Results showed, also, stimulation of M. aeruginosa growth. The highest growth increase in 100 μl/100 ml treatment with 50% acetone extract had a percentage rate (R of 94.66. On the contrary, treatment with ethanol extract recorded the highest inhibitory effect, thus in 1.5 μl/100 ml treatment with 50% Ceratophyllum ethanol extract R recorded −87.54, sustaining LC50 value of 1.12 μl/100 ml. The highest stimulating effect in 105 μl/100 ml treatment with 50% Ceratophyllum acetone extracts against O. tenuis was; R, 169.4. The highest inhibition in 1500 μl/100 ml treatment with 50% Ceratophyllum ethanol extracts against O. tenuis was; R −74.32, with LC50 0.830 μl/100 ml. While, the highest inhibition by 50% and 100% Potamogeton acetone or ethanol extracts against M. aeruginosa was

  16. Fluid electrodes for submersible robotics based on dielectric elastomer actuators

    Science.gov (United States)

    Christianson, Caleb; Goldberg, Nathaniel; Cai, Shengqiang; Tolley, Michael T.

    2017-04-01

    Recently, dielectric elastomer actuators (DEAs) have gathered interest for soft robotics due to their low cost, light weight, large strain, low power consumption, and high energy density. However, developing reliable, compliant electrodes for DEAs remains an ongoing challenge due to issues with fabrication, uniformity of the conductive layer, and mechanical stiffening of the actuators caused by conductive materials with large Young's moduli. In this work, we present a method for preparing, patterning, and utilizing conductive fluid electrodes. Further, when we submerse the DEAs in a bath containing a conductive fluid connected to ground, the bath serves as a second electrode, obviating the need for depositing a conductive layer to serve as either of the electrodes required of most DEAs. When we apply a positive electrical potential to the conductive fluid in the actuator with respect to ground, the electric field across the dielectric membrane causes charge carriers in the solution to apply an electrostatic force on the membrane, which compresses the membrane and causes the actuator to deform. We have used this process to develop a tethered submersible robot that can swim in a tank of saltwater at a maximum measured speed of 9.2 mm/s. Since saltwater serves as the electrode, we overcome buoyancy issues that may be a challenge for pneumatically actuated soft robots and traditional, rigid robotics. This research opens the door to low-power underwater robots for search and rescue and environmental monitoring applications.

  17. Recent Progress on Submersions: A Survey and New Properties

    Directory of Open Access Journals (Sweden)

    Gabriel Picavet

    2013-01-01

    Full Text Available This paper is a survey about recent progress on submersive morphisms of schemes combined with new results that we prove. They concern the class of quasicompact universally subtrusive morphisms that we introduced about 30 years ago. They are revisited in a recent paper by Rydh, with substantial complements and key results. We use them to show Artin-Tate-like results about the 14th problem of Hilbert, for a base scheme either Noetherian or the spectrum of a valuation domain. We look at faithfully flat morphisms and get “almost” Artin-Tate-like results by considering the Goldman (finite type points of a scheme. Bjorn Poonen recently proved that universally closed morphisms are quasicompact. By introducing incomparable morphisms of schemes, we are able to characterize universally closed surjective morphisms that are either integral or finite. Next we consider pure morphisms of schemes introduced by Mesablishvili. In the quasicompact case, they are universally schematically dominant morphisms. This leads us to a characterization of universally subtrusive morphisms by purity. Some results on the schematically dominant property are given. The paper ends with properties of monomorphisms and topological immersions, a dual notion of submersions.

  18. Aquatic Plant Management Program current status and seasonal workplan

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-07-01

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

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

    Science.gov (United States)

    1992-06-01

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

  20. Application of macrophytes as biosorbents for radioactive liquid waste treatment; Aplicacao de macrofitas como biossorventes no tratamento de rejeitos radioativos liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Ludmila Cabreira

    2016-07-01

    Radioactive waste as any other type of waste should be treated and disposed adequately. It is necessary to consider its physical, chemical and radiological characteristics for choosing the appropriate action for the treatment and final disposal. Many treatment techniques currently used are economically costly, often invalidating its use and favoring the study of other treatment techniques. One of these techniques is biosorption, which demonstrates high potential when applied to radioactive waste. This technology uses materials of biological origin for removing metals. Among potential biosorbents found, macrophyte aquatics are useful because they may remove uranium present in the liquid radioactive waste at low cost. This study aims to evaluate the biosorption capacity of macrophyte aquatics Pistia stratiotes, Limnobium laevigatum, Lemna sp and Azolla sp in the treatment of liquid radioactive waste. This study was divided into two stages, the first one is characterization and preparation of biosorption and the other is tests, carried out with uranium solutions and real samples. The biomass was tested in its raw form and biosorption assays were performed in polypropylene vials containing 10 ml of solution of uranium or 10ml of radioactive waste and 0.20g of biomass. The behavior of biomass was evaluated by sorption kinetics and isotherm models. The highest sorption capacities found was 162.1 mg / g for the macrophyte Lemna sp and 161.8 mg / g for the Azolla sp. The equilibrium times obtained were 1 hour for Lemna sp, and 30 minutes for Azolla sp. With the real waste, the macrophyte Azolla sp presented a sorption capacity of 2.6 mg / g. These results suggest that Azolla sp has a larger capacity of biosorption, therefore it is more suitable for more detailed studies of treatment of liquid radioactive waste. (author)

  1. Avaliação operacional do controle mecânico de plantas aquáticas imersas no reservatório de Jupiá Operational evaluation of mechanical control of aquatic macrophytes submerged in the Jupia reservoir

    Directory of Open Access Journals (Sweden)

    E.D. Velini

    2005-06-01

    Full Text Available O presente trabalho foi realizado com o objetivo de estudar a coleta e o descarte de plantas aquáticas em diferentes locais e infestações do sistema Tietê/Paraná, no reservatório de Jupiá. A operação foi realizada com auxílio de instrumentação instalada em uma colhedora de plantas aquáticas, com sistema de GPS dotado de sinal de correção diferencial. Os tempos gastos para carregar e descarregar a colhedora foram determinados por cronometragem, e a distância do ponto final de coleta ao ponto de descarte e o tempo de deslocamento, por cronometragem e uso de GPS convencional. Em algumas coletas foram demarcados polígonos, instruindo-se o operador a trabalhar exclusivamente na área correspondente. A interpretação dos resultados permitiu determinar a participação do tempo de coleta em relação ao tempo total de operação, indicando um valor significativo do ponto de vista operacional (>70%. Considerando o descarte em áreas infestadas com "taboa", o deslocamento total médio foi de apenas 383 m, com gasto médio de 200,96 s. Os valores de capacidade operacional da colhedora oscilaram entre 0,23 e 1,60 ha h-1, indicando valor médio de 4,48 ha dia-1. A maior limitação à capacidade operacional associou-se à velocidade média de deslocamento, com maior agravante em áreas com altas infestações ou profundas. Considerando-se o deslocamento da colhedora, houve grande dificuldade de orientação em condições normais de operação, inviabilizando a manutenção de espaçamentos uniformes entre as faixas de coleta e sobrepondo as passagens. Conclui-se que a avaliação operacional indicou a impossibilidade de operar a colhedora sem o auxílio de um sistema de navegação que permita orientar a sua movimentação nas áreas de controle.This work aimed to study the harvest and discard of aquatic plants from different places and infestation in the Tiete/Parana River system. The operation was performed with equipment installed at

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

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  3. Physiological performance and thermal tolerance of major Red Sea macrophytes

    KAUST Repository

    Weinzierl, Michael S.

    2017-12-01

    As anthropogenically-forced ocean temperatures continue to rise, the physiological response of marine macrophytes becomes exceedingly relevant. The Red Sea is a semi-isolated sea- the warmest in the world (SST up to 34°C) - already exhibiting signs of rapid warming rates exceeding those of other tropical oceans. This will have profound effects on the physiology of marine organisms, specifically marine macrophytes, which have direct influence on the dynamic carbonate system of the Red Sea. The aim of this paper is to define the physiological capability and thermal optima and limits of six ecologically important Red Sea macrophytes- ranging from seagrasses to calcifying and non-calcifying algae- and to describe the effects of increasing thermal stress on the performance and limits of each macrophyte in terms of activation energy. Of the species considered, Halophila stipulacae, Halimeda optunia, Halimeda monile and Padina pavonica thrive in thermal extremes and may be more successful in future Red Sea warming scenarios. Specifically, Halimeda opuntia increased productivity and calcification rates up to 38°C, making it the most thermally resilient macrophyte. Halophila stipulacae is the most productive seagrass, and hence has the greatest positive effect on Omega saturation state and offers chemical buffer capacity to future ocean acidification.

  4. Macrophyte Community Response to Nitrogen Loading and ...

    Science.gov (United States)

    Empirical determination of nutrient loading thresholds that negatively impact seagrass communities have been elusive due to the multitude of factors involved. Using a mesocosm system that simulated Pacific Northwest estuaries, we evaluated macrophyte metrics across gradients of NO3 loading (0, 1.5, 3 and 6x ambient) and temperature (10 and 20 °C). Macroalgal growth, biomass, and C:N responded positively to increased NO3 load and floating algal mats developed at 20 ºC. Zostera japonica metrics, including C:N, responded more to temperature than to NO3 loading. Z. marina biomass exhibited a negative temperature effect and in some cases a negative NO3 effect, while growth rate increased with temperature. Shoot survival decreased at 20 ºC but was not influenced by NO3 loading. Wasting disease index exhibited a significant temperature by NO3 interaction consistent with increased disease susceptibility. Community shifts observed were consistent with the nutrient loading hypothesis at 20 ºC, but there was no evidence of other eutrophication symptoms due to the short residence time. The Nutrient Pollution Index tracked the NO3 gradient at 10 ºC but exhibited no response at 20 ºC. We suggest that systems characterized by cool temperatures, high NO3 loads, and short residence time may be resilient to many symptoms of eutrophication. Estuarine systems characterized by cool temperatures, high nutrient loads and rapid flushing may be resilient to some symptoms

  5. Positioning of semi-submersibles with roll and pitch damping

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, A.J. [ABB Industri AS, Oslo (Norway); Strand, J.P. [Norwegian University of Science and Technology, Trondheim (Norway). Dept. of Engineering Cybernetics

    1999-07-01

    Dynamic positioning and thruster assisted position mooring of ships and floating marine constructions include different control functions for automatic positioning in the horizontal plane. A three degrees of freedom multivariable controller with feedback signals from surge, sway and yaw, either of linear or nonlinear type, can be regarded as adequate for the control objective for most surface vessels. However, for certain marine constructions with discernible coupling characteristics in the dynamics between the horizontal plane (surge, sway and yaw) and vertical plane (heave, roll and pitch), undesirably large roll and pitch oscillations may be induced by the thruster actions. Especially for constructions with natural periods in roll and pitch within the bandwidth of the positioning controller, the thruster induced oscillations in roll and pitch may become limitable on the operation. In this paper a new multivariable control law accounting for both horizontal and vertical motions is proposed. Simulations with a semi-submersible demonstrate the effect of the proposed control strategy. (author)

  6. Performance evaluation of a transformerless multiphase electric submersible pump system

    Directory of Open Access Journals (Sweden)

    Ahmed A. Hakeem

    2014-08-01

    Full Text Available Using of low-voltage variable-frequency drive followed by a step-up transformer is the most preferable way to feed an electrical submersible pump motor. The existence of long feeder between the motor and drive systems usually causes over-voltage problems because of the travelling wave phenomenon, which makes the employment of filter networks on the motor or inverter terminals mandatory. The so-called boost-inverter inherently can solve this problem with filter-less operation as it offers a direct sinusoidal output voltage. As boost inverters have voltage boosting capability, it can provide a transformer-less operation as well. This study investigates the performance of a five-phase modular winding induction machine fed from a boost-inverter through a long feeder. A simulation study using a 1000 Hp system and experimental investigation on a 1 Hp prototype machine are used to support the presented approach.

  7. Submersion Quenching of Undercooled Liquid Metals in an Electrostatic Levitator

    Science.gov (United States)

    SanSoucie, Michael P.; Rogers, Jan R.

    2016-01-01

    The NASA Marshall Space Flight Center (MSFC) electrostatic levitation (ESL) laboratory has a long history of providing materials research and thermophysical property data. The laboratory has recently added a new capability, a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals and alloys. This is the first submersion quench system inside an electrostatic levitator. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, titanium-zirconium-nickel alloys, and silicon-cobalt alloys. This rapid quench system will allow materials science studies of undercooled materials and new materials development, including studies of metastable phases and transient microstructures. In this presentation, the system is described and some initial results are presented.

  8. 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

  9. North Carolina Seagrass Submersed Rooted Vasculars 1990 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

  10. North Carolina Seagrass Submersed Rooted Vasculars 1990 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

  11. North Carolina Seagrass Submersed Rooted Vasculars 1990 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

  12. North Carolina Seagrass Submersed Rooted Vasculars 1990 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

  13. Macrophytes as potential biomonitors in peri-urban wetlands of the Middle Parana River (Argentina).

    Science.gov (United States)

    Alonso, Xenia; Hadad, Hernán Ricardo; Córdoba, Carlos; Polla, Wanda; Reyes, María Silvina; Fernández, Viviana; Granados, Inés; Marino, Luis; Villalba, Andrea

    2018-01-01

    The aims of this study were to measure the concentrations of nutrients and pollutants in peri-urban wetlands, to analyze the plant morphology of the most representative macrophyte species, and to determine their potential use as biomonitors. Four wetlands in the Middle Paraná River floodplain evidencing contamination or anthropogenic impact were studied. The studied species were Typha domingensis Pers., Eichhornia crassipes (Mart.) Solms., Alternanthera philoxeroides (Mart.) Griseb., and Pistia stratiotes L. Besides, the same plant species from an uncontaminated wetland considered as control were studied. A. philoxeroides showed the highest total phosphorus (TP) concentration in leaves throughout the study, while the other species showed a higher TP concentration in roots than in leaves. Since metal concentration in A. philoxeroides tissues was always higher than in sediment, further studies focused on its phytoremediation capacity should be carried out. T. domingensis exhibited the highest Zn concentrations in roots followed by Pb, and E. crassipes presented the highest values of Pb concentrations in roots. The aerial part height of the plants from peri-urban wetlands was significantly higher than that of the plants from the control, while the root length was significantly lower. The root length of P. stratiotes showed a negative correlation with soluble reactive phosphorus (SRP) concentration in water. All the root anatomical parameters of T. domingensis and E. crassipes showed a positive correlation with nitrate and ammonium concentrations in water. The studied macrophytes evidenced a high tolerance, enabling them to grow and survive in peri-urban wetlands that receive pollution from different sources. The use of aquatic and wetland plants as contaminant bioindicators and bioaccumulators in the Middle Paraná River floodplain is completely feasible.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  15. Submersible Data (Dive Trackpoints) for Operation Deep Scope 2007 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II along its track during nineteen dives of the 2007 "Operation Deep Scope" expedition sponsored...

  16. Submersible Data (Dive Waypoints) for Bioluminescence 2009 - Office of Ocean Exploration and Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II at waypoints along its track during seventeen dives of the 2009 "Bioluminescence" expedition...

  17. Submersible Data (Dive Trackpoints) for Life on the Edge 2004 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link I along its track during twenty-five dives of the 2004 "Life on the Edge" expedition sponsored by...

  18. Submersible Data (Dive Waypoints) for Life on the Edge 2005 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link I at waypoints along its track during nineteen dives of the 2005 "Life on the Edge" expedition...

  19. Submersible Data (Dive Waypoints) for Investigating the Charleston Bump 2003 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II at waypoints along its track during fourteen dives of the 2003 "Investigating the Charleston...

  20. Vomiting is not associated with poor outcomes in pediatric victims of unintentional submersions.

    Science.gov (United States)

    Farr, Kimberley M; Camp, Elizabeth A; Yusuf, Shabana; Shenoi, Rohit P

    2015-05-01

    The outcome of submersion victims depends on submersion duration and the availability of timely and effective resuscitation. The prognostic implication of vomiting during resuscitation of submersion victims is unclear. The study sought to determine whether vomiting during resuscitation in children treated for unintentional submersion injuries adversely impacts outcome. This was a retrospective study of unintentional submersion victims under age 18 treated at an urban tertiary-care children's hospital from 2003-2009. Submersion and victim details were obtained from hospital, EMS, and fatality records. Outcomes studied were survival at 24 hours and condition (Favorable: good/mild impairment or Poor: death/severe disability) at hospital discharge. Descriptive comparisons between emesis groups (yes/no) and categorical covariates were analyzed. There were 281 victims. The median age was 3 years; 66% were males. Most incidents occurred at swimming pools (77%) and bathtubs (16%). Most were hospitalized (83%). The presence or absence of emesis was documented in 246 (88%). Victims with emesis were significantly less likely to have apnea or be intubated in the ED, have a low ED GCS or die. No patient who had emesis died at 24 hours or had a poor outcome at hospital discharge. Victims who had emesis post-resuscitation were significantly more likely to have received CPR or chest compressions than rescue breaths. Emesis in pediatric submersion victims is inversely associated with death at 24 hours or poor outcome at hospital discharge. The relationship between emesis and the adequacy of resuscitation of pediatric submersion victims needs to be further studied. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Air-gap effect on life boat arrangement for a semi-submersible FPU

    OpenAIRE

    Kim, Mun-Sung; Park, Hong-Shik; Jung, Kwang-Hyo; Chun, Ho-Hwan

    2016-01-01

    In the offshore project such as semi-submersible FPU and FPSO, the free fall type life boat called TEMPSC (Totally Enclosed Motor Propelled Survival Craft) has been installed for the use of an emergency evacuation of POB (People on Board) from the topside platform. For the design of life boat arrangement for semi-submersible FPU in the initial design stage, the drop height and launch angle are required fulfill with the limitation of classification society rule and Company requirement, includi...

  2. Submersible Unmanned Aerial Vehicle: Configuration Design and Analysis Based on Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Wang Qinyang

    2017-01-01

    Full Text Available Submersible aerial vehicle is capable of both flying in the air and submerging in the water. Advanced Research Project Agency (DARPA outlined a challenging set of requirements for a submersible aircraft and solicited innovative research proposals on submersible aircraft since 2008. In this paper, a conceptual configuration design scheme of submersible unmanned aerial vehicle is proposed. This submersible UAV lands on the surface of water, then adjusts its own density to entry water. On the contrary, it emerges from water by adjusting its own density and then takes off from the surface of water. Wing of the UAV is whirling wing. It is set along aircraft’s fuselage while submerging for lift reduction. We analysis aerodynamic and hydrodynamic performance of this UAV by CFD method, especially compare the hydrodynamic performance of the whirling wing configuration and normal configuration. It turns out that whirling wing is beneficial for submerging. This result proves that the configuration design scheme proposed in this paper is feasible and suitable for a submersible unmanned aerial vehicle.

  3. Invasive submerged freshwater macrophytes are more plastic in their response to light intensity than to the availability of free CO2 in air-equilibrated water

    DEFF Research Database (Denmark)

    Eller, Franziska; Alnoee, Anette B.; Boderskov, Teis

    2015-01-01

    1. The future increase in the atmospheric CO2 concentration is likely to affect the growth and performance of submerged freshwater macrophytes because of higher concentrations of free CO2 in the water at air equilibrium. We measured the plastic responses to free CO2 and light for several traits...... of four invasive aquatic plants (Elodea canadensis, Egeria densa, Hydrilla verticillata and Ceratophyllum demersum) that use bicarbonate. 2. The plants were grown in standard culture media at either high (HiC, c. 50 lmol L 1) or low concentrations of free CO2 (LowC, c. 19 lmol L 1) combined with high (Hi...

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  6. Macrophyte abundance and water quality status of three impacted ...

    African Journals Online (AJOL)

    Assessment of macrophyte abundance and water quality of three impacted inlet streams along Ikpa River Basin were investigated. A 5m x 5m quadrat through systematic sampling was used to sample the vegetation for density and frequency of species. Sediment and water samples were collected and analyzed using ...

  7. The influence of the community of water macrophytes on regulation ...

    African Journals Online (AJOL)

    plzfg

    Numerous investigations have shown that natural biohydrocommunities may be of great help in preventing the introduction of pollutants into waters (Banuelos et al. 1997; Amaya-Chávez et al. 2006). Macrophytes, the prime components of broad shallow waters, may play a key role in the processes (Singhal & Mahto 2004; ...

  8. Phytoplankton responses to changes in macrophyte density in a ...

    African Journals Online (AJOL)

    The response of phytoplankton population dynamics to changes in densities of Nymphaea lotus L. and Polygonum limbatum Meisn. was studied in an artificial pond in Zaria, Nigeria, from June to November 2007. Antagonistic effects of these macrophytes on Netrium sp., Staurastrum sp., Ulothrix sp., Marssionella sp. and ...

  9. Experiments on growth interactions between two invasive macrophyte species

    NARCIS (Netherlands)

    Barrat-Segretain, M-H.; Elger, A.F.

    2004-01-01

    The success of invasive species has been attributed to the ability to displace other species by direct competition. We studied growth and possible competition between the two macrophyte species Elodea nuttallii and E. canadensis, because the former has been observed to replace the latter in the

  10. The power supply system model of the process submersible device with AC power transmission over the cable-rope

    OpenAIRE

    Rulevskiy, V. M.; Bukreev, Viktor Grigorievich; Kuleshova, Elena Olegovna; Shandarova, Elena Borisovna; Shandarov, S.M.; Vasilyeva, Yu. Z.

    2017-01-01

    A practical problem of power supply system modeling for the process submersible device with AC power transmission over the cable-rope was considered. The problem is highly relevant in developing and operation of submersible centrifugal pumps and submersibles. The results of modeling a symmetrical three-phase power supply system and their compliance with the real data are given at the paper. The obtained results in the mathematical and simulation models were similar.

  11. Life extension of semi-submersible drilling unit

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, I.; Sinclair, C.I.K. [TWI, Cambridge (United Kingdom). Structural Integrity Dept.; Magne, E. [Schlumberger Sedco Forex, Montrouge (France)

    1995-12-31

    This paper describes the life extension of a semi-submersible drilling rig built in the early 1970`s. A nominal design life of 20 years was estimated at the time of building; however, in the interim period, numerous improvements have been made in fatigue life estimation ad life improvement techniques, raising the possibility that a further 20 years of operation could be considered. The life extension strategy made use of a number of aspects of offshore technology which were not available at the time of construction of the rig. Finite element studies and results from offshore research programs were used to gauge the effect of fatigue life improvement techniques. The program demonstrated the feasibility of extending the operation of the rig for a further 20 years, with the interval between in-service inspection increased to every five years. It also provided a valuable database of fracture toughness data for the rig materials, which may be used in future work to address reliability issues.

  12. Submersible Spectrofluorometer for Real-Time Sensing of Water Quality.

    Science.gov (United States)

    Puiu, Adriana; Fiorani, Luca; Menicucci, Ivano; Pistilli, Marco; Lai, Antonia

    2015-06-18

    In this work, we present a newly developed submersible spectrofluorometer (patent pending) applied to real-time sensing of water quality, suitable for monitoring some important indicators of the ecological status of natural waters such as chlorophyll-a, oil and protein-like material. For the optomechanical realization of the apparatus, a novel conceptual design has been adopted in order to avoid filters and pumps while maintaining a high signal-to-noise ratio. The elimination of filters and pumps has the advantage of greater system simplicity and especially of avoiding the risk of sample degradation. The use of light-emitting diodes as an excitation source instead of Xe lamps or laser diodes helped save on size, weight, power consumption and costs. For sensor calibration we performed measurements on water samples with added chlorophyll prepared in the laboratory. The sensor functionality was tested during field campaigns conducted at Albano Lake in Latium Region of Italy as well as in the Herzliya Harbor, a few kilometers North East of Tel Aviv in Israel. The obtained results are reported in the paper. The sensitivity achieved for chlorophyll-a detection was found to be at least 0.2 µg/L.

  13. Characterization of Root-Associated Methanotrophs from Three Freshwater Macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia†

    Science.gov (United States)

    Calhoun, A.; King, G. M.

    1998-01-01

    Root-associated methanotrophic bacteria were enriched from three common aquatic macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia. At least seven distinct taxa belonging to groups I and II were identified and presumptively assigned to the genera Methylosinus, Methylocystis, Methylomonas, and Methylococcus. Four of these strains appeared to be novel on the basis of partial 16S ribosomal DNA sequence analysis. The root-methanotroph association did not appear to be highly specific, since multiple methanotrophs were isolated from each of the three plant species. Group II methanotrophs were isolated most frequently; though less common, group I isolates accounted for three of the seven distinct methanotrophs. Apparent Km values for methane uptake by representative cultures ranged from 3 to >17 μM; for five of the eight cultures examined, apparent Km values agreed well with apparent Km estimates for plant roots, suggesting that these strains may be representative of those active in situ. PMID:16349515

  14. Characterization of Root-Associated Methanotrophs from Three Freshwater Macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia.

    Science.gov (United States)

    Calhoun, A; King, G M

    1998-03-01

    Root-associated methanotrophic bacteria were enriched from three common aquatic macrophytes: Pontederia cordata, Sparganium eurycarpum, and Sagittaria latifolia. At least seven distinct taxa belonging to groups I and II were identified and presumptively assigned to the genera Methylosinus, Methylocystis, Methylomonas, and Methylococcus. Four of these strains appeared to be novel on the basis of partial 16S ribosomal DNA sequence analysis. The root-methanotroph association did not appear to be highly specific, since multiple methanotrophs were isolated from each of the three plant species. Group II methanotrophs were isolated most frequently; though less common, group I isolates accounted for three of the seven distinct methanotrophs. Apparent K(m) values for methane uptake by representative cultures ranged from 3 to >17 muM; for five of the eight cultures examined, apparent K(m) values agreed well with apparent K(m) estimates for plant roots, suggesting that these strains may be representative of those active in situ.

  15. Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    CV. Silva

    Full Text Available Marginal lakes are characterised by their having high biological diversity due to the presence of aquatic macrophytes in their coastal zones, providing habitats for refuge and food for animal community members. Among the fauna components associated with macrophytes, aquatic macroinvertebrates are important because they are an energy source for predators and fish. In six lakes and two different seasons (March and August 2009, the ecological attributes of aquatic macroinvertebrate community associated with Eichhornia azurea were compared and the controlling environmental factors were identified. Since the attributes of macroinvertebrate community are strictly associated with abiotic variables of each distinct habitat, our hypothesis was that each site associated with the same floating aquatic macrophyte (E. azurea should have a typical composition and density of organisms. We identified 50 taxa of macroinvertebrates, with greater taxa richness for aquatic insects (37 taxa divided into eight orders; the order Diptera being the most abundant in the two study periods. On the other hand, higher values of total taxa richness were recorded in August. Dissolved oxygen and pH presented the greatest number of significant positive correlations with the different taxa. The animals most frequently collected in the six lakes in March and August 2009 were Hirudinea, Oligochaeta, Hydrachnidae, Conchostraca, Ostracoda, Noteridae, Ceratopogonidae, Chironomidae, Culicidae, Caenidae, Pleidae, Aeshnidae, Libellulidae, Coenagrionidae and Nematoda. Only densities of Trichoptera, Ostracoda and Conchostraca presented the highest significant differences between lakes in both study periods and considering the composition of macroinvertebrates no significant differences were registered for macroinvertebrate composition.

  16. Commercial Submersible Mixing Pump For SRS Tank Waste Removal - 15223

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Mike [Savannah River Remediation, LLC., Aiken, SC (United States); Herbert, James E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scheele, Patrick W. [Savannah River Remediation, LLC., Aiken, SC (United States)

    2015-01-12

    The Savannah River Site Tank Farms have 45 active underground waste tanks used to store and process nuclear waste materials. There are 4 different tank types, ranging in capacity from 2839 m3 to 4921 m3 (750,000 to 1,300,000 gallons). Eighteen of the tanks are older style and do not meet all current federal standards for secondary containment. The older style tanks are the initial focus of waste removal efforts for tank closure and are referred to as closure tanks. Of the original 51 underground waste tanks, six of the original 24 older style tanks have completed waste removal and are filled with grout. The insoluble waste fraction that resides within most waste tanks at SRS requires vigorous agitation to suspend the solids within the waste liquid in order to transfer this material for eventual processing into glass filled canisters at the Defense Waste Processing Facility (DWPF). SRS suspends the solid waste by use of recirculating mixing pumps. Older style tanks generally have limited riser openings which will not support larger mixing pumps, since the riser access is typically 58.4 cm (23 inches) in diameter. Agitation for these tanks has been provided by four long shafted standard slurry pumps (SLP) powered by an above tank 112KW (150 HP) electric motor. The pump shaft is lubricated and cooled in a pressurized water column that is sealed from the surrounding waste in the tank. Closure of four waste tanks has been accomplished utilizing long shafted pump technology combined with heel removal using multiple technologies. Newer style waste tanks at SRS have larger riser openings, allowing the processing of waste solids to be accomplished with four large diameter SLPs equipped with 224KW (300 HP) motors. These tanks are used to process the waste from closure tanks for DWPF. In addition to the SLPs, a 224KW (300 HP) submersible mixer pump (SMP) has also been developed and deployed within older style tanks. The SMPs are product cooled and

  17. Regulation of Root-Associated Methanotrophy by Oxygen Availability in the Rhizosphere of Two Aquatic Macrophytes

    OpenAIRE

    Calhoun, A.; King, G. M.

    1997-01-01

    The relative importance of oxygen for root-associated methanotrophy was examined by using sediment-free, intact freshwater marsh plants (Pontederia cordata and Sparganium eurycarpum) incubated in split chambers. The root medium contained approximately 100 (mu)M methane. Methane oxidation was calculated from the difference between methane loss from chambers in the presence and absence of 1 mM 1-allyl-2-thiourea, a methanotrophic inhibitor. When the root medium was oxic, methane oxidation accou...

  18. Regulation of root-associated methanotrophy by oxygen availability in the rhizosphere of two aquatic macrophytes.

    Science.gov (United States)

    Calhoun, A; King, G M

    1997-08-01

    The relative importance of oxygen for root-associated methanotrophy was examined by using sediment-free, intact freshwater marsh plants (Pontederia cordata and Sparganium eurycarpum) incubated in split chambers. The root medium contained approximately 100 (mu)M methane. Methane oxidation was calculated from the difference between methane loss from chambers in the presence and absence of 1 mM 1-allyl-2-thiourea, a methanotrophic inhibitor. When the root medium was oxic, methane oxidation accounted for 88 and 63% of the total methane depletion for S. eurycarpum and P. cordata, respectively; the remainder represented diffusional loss to the atmosphere via roots, stems, and leaves. Under suboxic conditions, methane oxidation was not detectable for S. eurycarpum but accounted for 68% of total methane depletion for P. cordata. The introduction of a biological oxygen sink, Pseudomonas aeruginosa, resulted in complete loss of methane oxidation in S. eurycarpum chambers under oxic conditions, while methane consumption continued (51.6% of total methane depletion) in P. cordata chambers. The differences between plant species were consistent with their relative ability to oxygenate their rhizospheres: during a suboxic incubation, dissolved oxygen decreased by 19% in S. eurycarpum chambers but increased by 232% for P. cordata. An in situ comparison also revealed greater methanotrophic activity for P. cordata than S. eurycarpum.

  19. Treatment efficiency of effluent prawn culture by wetland with floating aquatic macrophytes arranged in series

    Directory of Open Access Journals (Sweden)

    MNP Henares

    Full Text Available The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3 with three treatments (constructed wetlands and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm arranged sequentially, a wetland with E. crassipes only (Ec and a wetland with S. molesta only (Sm. The means of suspended particulate material (SPM, total inorganic nitrogen (TIN, total Kjeldahl nitrogen (TKN, P-orthophosphate (PO4-P and total phosphorus (TP of the treated effluents were compared using ANOVA followed by Tukey's test (P<0.05. The effluent treated in Ec and EcSm wetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%, TKN (33.7% and PO4-P (26.7% was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P. The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes, which forms an extensive area favorable to retention and adsorption of debris and absorption of nutrients.

  20. Allelopathic effect of the aquatic macrophyte, Stratiotes aloides, on natural phytoplankton

    NARCIS (Netherlands)

    Mulderij, G.; Mau, B.; Smolders, A.J.P.; Van Donk, E.

    2006-01-01

    A survey of different Dutch Stratiotes stands showed that the density of phytoplankton (except cyanobacteria) was always higher outside S. aloides than between the rosettes of S. aloides. Analyses of water samples revealed that nutrient limitation was unlikely to have caused the lower phytoplankton

  1. Treatment efficiency of effluent prawn culture by wetland with floating aquatic macrophytes arranged in series.

    Science.gov (United States)

    Henares, M N P; Camargo, A F M

    2014-11-01

    The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3) with three treatments (constructed wetlands) and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm) arranged sequentially, a wetland with E. crassipes only (Ec) and a wetland with S. molesta only (Sm). The means of suspended particulate material (SPM), total inorganic nitrogen (TIN), total Kjeldahl nitrogen (TKN), P-orthophosphate (PO4-P) and total phosphorus (TP) of the treated effluents were compared using ANOVA followed by Tukey's test (Pwetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%), TKN (33.7%) and PO4-P (26.7%) was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P). The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes, which forms an extensive area favorable to retention and adsorption of debris and absorption of nutrients.

  2. Enhanced effects of biotic interactions on predicting multispecies spatial distribution of submerged macrophytes after eutrophication

    OpenAIRE

    Song, Kun; Cui, Yichong; Zhang, Xijin; Pan, Yingji; Xu, Junli; Xu, Kaiqin; Da, Liangjun

    2017-01-01

    Abstract Water eutrophication creates unfavorable environmental conditions for submerged macrophytes. In these situations, biotic interactions may be particularly important for explaining and predicting the submerged macrophytes occurrence. Here, we evaluate the roles of biotic interactions in predicting spatial occurrence of submerged macrophytes in 1959 and 2009 for Dianshan Lake in eastern China, which became eutrophic since the 1980s. For the four common species occurred in 1959 and 2009,...

  3. Primary Production Dynamics of Two Dominant Macrophytes in Wular Lake, a Ramsar Site in Kashmir Himalaya

    Directory of Open Access Journals (Sweden)

    Naseer Ahmad Dar

    2012-12-01

    Full Text Available Growing season changes in the organic matter, organic carbon and chlorophyll content of the two dominant macrophytes, Nymphoides peltatum and Ceratophyllum demersum of Wular Lake, a Ramsar Site in Kashmir Himalaya were analysed during March- November 2011. The content of organic matter and organic carbon for Nymphoides peltatum were 114.1 g m-2 and 53.1 g C m-2 and Ceratophyllum demersum were 57.0 g m-2 and 26.4 g C m-2. Chlorophyll A (Chl a and chlorophyll A+B (Chl a+b pigments ranged from 1.75 mg g-1 (Chl a and 2.1mg g-1 (Chl a+b in Nymphoides peltatum to 4.41 mg g-1 (Chl a and 5.69 mg g-1 (Chl a+b in Ceratophyllum demersum. In full leaf out, the latter aquatic plants exceeded 15-20% coverage of the open water surface.Ceratophyllum demersum and Nymphoides peltatum achieved maximum growth in June and August respectively, but significant differences in their growth dynamics was observed. At the end of the vegetation period, these plants sink to the bottom and decompose.

  4. Hydrologic connection between ponds positively affects macrophyte alpha and gamma diversity but negatively affects beta diversity.

    Science.gov (United States)

    Akasaka, Munemitsu; Takamura, Noriko

    2012-05-01

    Connections between habitat patches can positively influence the number of species in respective patches, providing a basis for preferentially conserving interconnected patches. However, from a regional perspective, it is not known whether conserving multiple sets of interconnected habitat patches would include more species (i.e., show higher gamma diversity) than conserving multiple, unconnected, solitary patches. We studied aquatic macrophytes in 15 sets of unidirectionally interconnected ponds and 19 unconnected ponds and also tested whether alpha and beta diversity, expressed as the number of species and dissimilarity in species composition, respectively, differed between connected and unconnected ponds. We found that gamma diversity was higher in connected ponds than in unconnected ponds, even after controlling for surface area. This resulted from a higher alpha diversity in connected ponds, despite lower beta diversity. These results suggest that connections between habitat patches positively influence diversity at both local and regional scales. When the total surface area available for conservation is limited, interconnected habitat patches should be preferentially conserved.

  5. Ecological evaluation of transitional and coastal waters: A marine benthic macrophytes-based model

    Directory of Open Access Journals (Sweden)

    S. ORFANIDIS

    2001-12-01

    Full Text Available A model to estimate the ecological status and identify restoration targets of transitional and coastal waters was developed. Marine benthic macrophytic species (seaweeds, seagrasses were used to indicate shifts in the aquatic ecosystem from the pristine state with late-successional species (Ecological State Group I to the degraded state with opportunistic (ESG II species. The first group comprises species with a thick or calcareous thallus, low growth rates and long life cycles (perennials, whereas the second group includes sheet-like and filamentous species with high growth rates and short life cycles (annuals. Seagrasses were included in the first group, whereas Cyanophyceae and species with a coarsely branched thallus were included in the second group. The evaluation of ecological status into five categories from high to bad includes a cross comparison in a matrix of the ESGs and a numerical scoring system (Ecological Evaluation Index. The model could allow comparisons, ranking and setting of priorities at regional and national levels fulfilling the requirements of the EU Water Frame Directive. A successful application of the model was realized in selected lagoons of the Macedonian and Thrace region (North Greece and in the Saronic Gulf coastal ecosystems (Central Greece.

  6. Does the Lagoa do Peixe sandbar opening influence the macrophyte richness and composition in Southern Brazil wetlands?

    Directory of Open Access Journals (Sweden)

    Ana Silvia Rolon

    2013-03-01

    Full Text Available The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. This information is crucial for the management of the natural resources of the Lagoa do Peixe National Park, the unique Ramsar site in Southern Brazil. The following questions were analyzed: (1 Do richness and composition of aquatic macrophytes from Lagoa do Peixe floodplain varies temporarily according to the sandbar opening and closing? (2 Does the variation pattern of the macrophyte community changed according to the sandbar opening and closing? A set of eight sampling sites of 1ha were selected over the Lagoa do Peixe floodplain: four sites not influenced by the artificial sandbar opening and four sites influenced by this event, being two sites closer to the sandbar opening and the two sites distant to the sandbar opening. The samplings were carried out between November 2007 and October 2009. The results show that although the artificial sandbar breaching does not affect the aquatic macrophyte richness at the floodplain, it affects the dynamics of species composition. The hydrological variation related to this management can be the main factor of the continuous change in the species composition in the floodplain, especially in the Southern portion. In order to avoid impacts in the macrophyte conservation, the artificial sandbar opening should be considered carefully, since the area of study is one of the most important conservation units to wetland systems in Southern Brazil.La Lagoa do Peixe, en el sur de Brasil, tiene conexión artificial con el mar, porque cada año, al final del invierno, se abre un canal con tractor. Sin embargo, esta práctica se ha levado a cabo sin la evaluación de los efectos de esta apertura en la biodiversidad acuática. Las siguientes preguntas fueron analizadas: (1 ¿Varían la

  7. Macrophytes in the upper Paraná river floodplain: checklist and comparison with other large South American wetlands

    Directory of Open Access Journals (Sweden)

    Fernando Alves Ferreira

    2011-06-01

    Full Text Available Neotropical aquatic ecosystems have a rich aquatic flora. In this report, we have isted the aquatic flora of various habitats of the upper Paraná River floodplain by compiling data rom literature and records of our own continuous collections conducted during the period 2007-2009. Our main purposes were to assess the macrophyte richness in the Paraná floodplain, to compare it with other South American wetlands and to assess whether the number of species recorded in South American inventories has already reached an asymptote. We recorded a total of 153 species of macrophytes in the Upper Paraná River floodplain, belonging to 100 genera and 47 families. In our comparative analysis, a clear floristic split from other South American wetlands was shown, except for the Pantanal, which is the closest wetland to the Paraná floodplain and, therefore, could be considered a floristic extension of the Pantanal. The species accumulation curve provides evidence that sampling efforts should be reinforced in order to compile a macrophyte flora census for South America. The high dissimilarity among South American wetlands, together with the lack of an asymptote in our species accumulation curve, indicates that the sampling effort needs to be increased to account for the actual species richness of macrophytes in this region. Rev. Biol. Trop. 59 (2: 541-556. Epub 2011 June 01.Los ecosistemas acuáticos neotropicales tienen una rica flora acuática. En este informe, hemos hecho una lista de la flora acuática de diversos hábitats de la alta planicie de inundación del río Paraná mediante la compilación de datos de la literatura y los registros de nuestras colecciones propias realizadas durante el período 2007-2009. Nuestros principales objetivos fueron evaluar la riqueza de macrófitos en la llanura aluvial del Paraná, para compararlo con otros humedales de América del Sur y evaluar si el número de especies registradas en los inventarios suramericanos ya

  8. African Journal of Science and Technology (AJST) MACROPHYTES ...

    African Journals Online (AJOL)

    opiyo

    Sporobolus robus-tus. 0.0005. n.o. IRp totale. 6.334. 7.208. n.o = non observée. Tableau 7 : Indices d'impor-tance relative moyens des principaux macro-phytes observés sur les transects. N° Transects. Groupements. Oct Ma Oct Mai Oct Mai Oct Mai Nov Mai Nov Mai Nov Mai Nov Mai Nov Mai Nov Mai Nov Mai Nov Mai Nov ...

  9. Aquatic Therapy for Children

    Science.gov (United States)

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  10. Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

    Energy Technology Data Exchange (ETDEWEB)

    Taggart, M.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom); Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain)], E-mail: mark.taggart@uclm.es; Mateo, R. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain); Charnock, J.M.; Bahrami, F. [Synchrotron Radiation Department, CCLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Green, A.J. [Department of Wetland Ecology, Estacion Biologica de Donana, CSIC, Pabellon del Peru, Avenida Maria Luisa s/n, 41013 Seville (Spain); Meharg, A.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom)

    2009-03-15

    Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcollar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root + plaque' material in excess of 1000 mg kg{sup -1}, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcollar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. - Accumulation of metals with iron plaque on macrophyte roots in wetlands poses an ecotoxicological risk to certain herbivores.

  11. Aquatic plant surface as a niche for methanotrophs

    Science.gov (United States)

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

    2014-01-01

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

  12. Aquatic plant surface as a niche for methanotrophs

    Directory of Open Access Journals (Sweden)

    Naoko eYoshida

    2014-02-01

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

  13. New Navigation Post-Processing Tools for Oceanographic Submersibles

    Science.gov (United States)

    Kinsey, J. C.; Whitcomb, L. L.; Yoerger, D. R.; Howland, J. C.; Ferrini, V. L.; Hegrenas, O.

    2006-12-01

    We report the development of Navproc, a new set of software tools for post-processing oceanographic submersible navigation data that exploits previously reported improvements in navigation sensing and estimation (e.g. Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract OS32A- 0225, 2003). The development of these tools is motivated by the need to have post-processing software that allows users to compensate for errors in vehicle navigation, recompute the vehicle position, and then save the results for use with quantitative science data (e.g. bathymetric sonar data) obtained during the mission. Navproc does not provide real-time navigation or display of data nor is it capable of high-resolution, three dimensional (3D) data display. Navproc supports the ASCII data formats employed by the vehicles of the National Deep Submergence Facility (NDSF) operated by the Woods Hole Oceanographic Institution (WHOI). Post-processing of navigation data with Navproc is comprised of three tasks. First, data is converted from the logged ASCII file to a binary Matlab file. When loaded into Matlab, each sensor has a data structure containing the time stamped data sampled at the native update rate of the sensor. An additional structure contains the real-time vehicle navigation data. Second, the data can be displayed using a Graphical User Interface (GUI), allowing users to visually inspect the quality of the data and graphically extract portions of the data. Third, users can compensate for errors in the real-time vehicle navigation. Corrections include: (i) manual filtering and median filtering of long baseline (LBL) ranges; (ii) estimation of the Doppler/gyro alignment using previously reported methodologies; and (iii) sound velocity, tide, and LBL transponder corrections. Using these corrections, the Doppler and LBL positions can be recomputed to provide improved estimates of the vehicle position compared to those computed in real-time. The data can be saved in either binary or ASCII

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

    Science.gov (United States)

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

    2010-01-01

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

  15. Invertebrate grazing during the regenerative phase affects the ultimate structure of macrophyte communities

    NARCIS (Netherlands)

    Elger, A.F.; Willby, N.; Cabello-Martinez, M.

    2009-01-01

    1. Although the biomass of freshwater macrophytes consumed by invertebrate herbivores (excluding crayfish) is usually low, there is growing evidence that invertebrates do exert a structuring effect on macrophyte communities. To explain this, we postulated that the effect of invertebrates may be

  16. Competition between free-floating and submerged macrophytes in a future of climate change

    NARCIS (Netherlands)

    Netten, J.J.C.

    2011-01-01


    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor

  17. First steps in the Central-Baltic intercalibration exercise on lake macrophytes: where do we start?

    NARCIS (Netherlands)

    Tóth, L.G.; Poikane, S.; Penning, W.E.; Free, G.; Mäemets, H.; Kolada, A.; Hanganu, J.

    2008-01-01

    The Water Framework Directive (WFD 2000) defines macrophytes as one of the biological groups required for the ecological assessment of European surface waters. Several indices for macrophyte assessment have been proposed or are currently in use by different European states. As a first step towards

  18. Habitat related variation in UV tolerance of tropical marine red macrophytes is not temperature dependent

    NARCIS (Netherlands)

    van de Poll, W.H.; Bischof, K.; Buma, A.G.J.; Breeman, Arno

    Because tropical marine macrophytes experience high ultraviolet-B radiation (UVBR: 280-320 nm) it is assumed that they have high UV tolerance. This was investigated by examining the relative UV sensitivity of five Caribbean red macrophytes. Furthermore, the possibility of temperature dependence of

  19. Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil.

    Science.gov (United States)

    Paula-Bueno, M C; Fonseca-Gessner, A A

    2015-11-01

    Macrophytes in oxbow lakes represent an important substrate for the Coleoptera. Two oxbow lakes the Rio Paranapanema were studied and the other two Rio Mogi-Guaçu, in the State de São Paulo, Brasil. In this study, there is greater similarity between the communities of Coleoptera of lakes greater connectivity with the main river channel or the difference in the species of Salvinia collected in the lakes studied interferes Coleoptera fauna that uses as substrate. A total of 9,222 specimens of Coleoptera were collected and identified in 10 families and 40 genera. The analysis MDS for abundance of Coleoptera showed the grouping of the oxbow lakes the Paranapanema River and a distancing the oxbow lakes the Mogi-Guaçu. The PERMANOVA test did not reveal any difference in the fauna between the wet and dry periods. It was concluded that the connectivity between river and lake is not decisive for the richness and abundance of aquatic fauna of Coleoptera. Therefore, the richness and abundance of aquatic Coleoptera associated vary with the species of Salvinia used as substrate.

  20. Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil

    Directory of Open Access Journals (Sweden)

    M. C. Paula-Bueno

    Full Text Available Abstract Macrophytes in oxbow lakes represent an important substrate for the Coleoptera. Two oxbow lakes the Rio Paranapanema were studied and the other two Rio Mogi-Guaçu, in the State de São Paulo, Brasil. In this study, there is greater similarity between the communities of Coleoptera of lakes greater connectivity with the main river channel or the difference in the species of Salvinia collected in the lakes studied interferes Coleoptera fauna that uses as substrate. A total of 9,222 specimens of Coleoptera were collected and identified in 10 families and 40 genera. The analysis MDS for abundance of Coleoptera showed the grouping of the oxbow lakes the Paranapanema River and a distancing the oxbow lakes the Mogi-Guaçu. The PERMANOVA test did not reveal any difference in the fauna between the wet and dry periods. It was concluded that the connectivity between river and lake is not decisive for the richness and abundance of aquatic fauna of Coleoptera. Therefore, the richness and abundance of aquatic Coleoptera associated vary with the species of Salvinia used as substrate.

  1. 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.

  2. Geology of mud volcanos in the Eastern Mediterranean from combined sidescan and submersible surveys

    NARCIS (Netherlands)

    Zitter, T.A.C.; Huguen, C.; Woodside, J.M.

    2005-01-01

    Submersible observations and seafloor mapping over areas of mud volcanism in the eastern Mediterranean Sea reveal an abundance of methane-rich fluid emissions, as well as specific seep-associated fauna (e.g. tubeworms, bivalves and chemosynthetic bacteria) and diagenetic deposits (i.e. carbonates

  3. 77 FR 2957 - Application for Manufacturing Authority, Liberty Pumps, Inc. (Submersible and Water Pumps...

    Science.gov (United States)

    2012-01-20

    ... Foreign-Trade Zones Board Application for Manufacturing Authority, Liberty Pumps, Inc. (Submersible and... manufacturing authority on behalf of Liberty Pumps, Inc., located in Bergen, New York. The application was... regulations of the Board (15 CFR part 400). It was formally filed on January 12, 2012. The Liberty Pumps, Inc...

  4. Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic...

  5. Submersion time, depth, substrate type and sampling method as variation sources of marine periphyton

    NARCIS (Netherlands)

    Richard, M.; Trottier, C.; Verdegem, M.C.J.; Hussenot, J.M.E.

    2009-01-01

    Periphyton is an additional food source in African and Asian brackish and freshwater fish ponds. The present study was a preliminary assessment of periphyton development on artificial substrates in temperate marine ponds. The effects of submersion time, substrate type, water depth, and total or

  6. Increased power generation from primary sludge by a submersible microbial fuel cell and optimum operational conditions

    DEFF Research Database (Denmark)

    Vologni, Valentina; Kakarla, Ramesh; Angelidaki, Irini

    2013-01-01

    Microbial fuel cells (MFCs) have received attention as a promising renewable energy technology for waste treatment and energy recovery. We tested a submersible MFC with an innovative design capable of generating a stable voltage of 0.250 ± 0.008 V (with a fixed 470 Ω resistor) directly from prima...

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

    Science.gov (United States)

    1980-06-01

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

  8. Biomonitoring of selected freshwater macrophytes to assess lake trace element contamination: a case study of Nal Sarovar Bird Sanctuary, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Rita N. KUMAR

    2006-02-01

    Full Text Available A biomonitoring study was carried out at Nal Sarovar Bird Sanctuary, a proposed Ramsar site, Gujarat State, India, to ascertain the degree of trace element contamination. The study focused on assessment of trace element contamination in certain aquatic macrophytes to be used as biomonitors, in comparison with the sediments (abiotic monitor for heavy metal pollution. Good information was provided by analyzing roots, stems and leaves of native aquatic plants (biomonitors represented by eight species: Bergia odorata, Hydrilla verticillata, Ipomoea aquatica, Najas graminea, Nelumbo nucifera, Phragmites karka, Typha angustata and Vellisnaria spiralis, alongwith surface sediments and water, were analyzed for Cd, Co, Cu, Cu, Ni, Pb and Zn contamination. The highest concentrations of the trace elements were measured in Ipomoea aquatica and the lowest in Bergia odorata. Based on the concentration and toxicity status observed in the lake's vegetation, the six metals are arranged in the following decreasing order: Zn > Cu > Ni > Co > Pb > Cd. Compared with the standard, normal and critical toxicity range in plants, the detected values of Cd and Pb falls within normal range, while that of Co, Ni and Cu were within the critical range. However, Zn showed the highest concentration and alarming toxicity levels, which is considered as one of the most hazardous pollutants in Nal Sarovar Bird Sanctuary. Certain aquatic macrophytes species are also proposed as biomonitors for the investigated heavy metal pollutants. Such result was significant in the plant species such as Ipomoea aquatica and Phragmites karka, which are the two most useful species in biomonitoring studies due to their ability to accumulate elements in high concentration in the roots and their availability throughout the year. The results showed the significant difference in accumulation rate of some metals like Zn, Cu and Ni in different plant organs, which showed more accumulation in root than

  9. Sediment phosphate composition in relation to emergent macrophytes in the Doñana Marshes (SW Spain).

    Science.gov (United States)

    Reina, M; Espinar, J L; Serrano, L

    2006-03-01

    We have studied the effect of the presence of emergent macrophytes on the sediment phosphate composition of a eutrophic shallow marsh on the NE margin of Doñana (SW Spain). Top sediment and water samples were collected from both the open-water and the vegetated sites at three areas covered by different plant species: Scirpus maritimus, Juncus subulatus and Phragmites australis. The concentration of organic matter was significantly higher in the top sediment of sites covered by vegetation than in their adjacent open-water sites at the three vegetation areas. The P-fractional composition showed that the sediment was dominated by the inorganic P-fractions in all cases, reaching the highest concentration in the Ca-bound P-fraction (281-372 microg g(-1) d.w.). The sum of all P-fractions was significantly higher in the top sediment of the sites covered by J. subulatus and S. maritimus than in their adjacent open-water sites, and so were the org-P fraction extracted by hot NaOH and the concentration of phytate within this fraction. Deposition of plant material on the top sediment of areas vegetated by J. subulatus and S. maritimus explains these differences. The P-fractional composition of the seeds from J. subulatus showed that they contained a large proportion of organic P-fractions, particularly of the fraction extracted by hot NaOH (1868 microg g(-1) d.w., 85% of which was phytate). The presence of emergent macrophytes, therefore, influenced the distribution of P-fractions in the sediment depending on plant species. The P-bioavailability of shallow aquatic systems must be fully understood if wetlands are to be protected from further eutrophication.

  10. Journal of East African Natural History - Vol 101, No 1 (2012)

    African Journals Online (AJOL)

    ... from Hydrilla Verticillata (Hydrocharitaceae) and other submersed aquatic Macrophytes in Lake Bisina and other Ugandan Lakes · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Robert S Copeland, Brian Gidudu, Fred Wanda, John H Epler, James P Cuda, William A Overholt.

  11. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  12. 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.

  13. Nutrient and grazing factors in relation to phytoplankton level in a eutrophic shallow lake: the effect of low macrophyte abundance.

    Science.gov (United States)

    Lau, S S S; Lane, S N

    2002-08-01

    The ability of submerged macrophytes to moderate the structure of food webs with respect to lake eutrophication management has been intensively studied in recent years. Many lake managers have adopted the option of increasing macrophyte abundance in order to restore eutrophic waters, with a view to improve water quality, increase water transparency and reduce phytoplankton biomass. These studies are mostly based upon the comparison of macrophyte-rich and macrophyte-free waters. There is less quantitative information on how different levels of macrophyte abundance, in particular very low levels, influence ecosystem structure, or vice versa, within the same ecosystem. This paper takes a multivariate statistical approach to examine ecosystem function with low macrophyte abundance (ca. 5%) in the context of nutrient-phytoplankton-zooplankton interaction in a eutrophic shallow lake. It shows that with low levels of macrophyte coverage, phytoplankton biomass was only limited by nutrient (TP and Si) availability, whilst nutrient (Si) as well as grazing (zooplankton and Daphnia) factors were both limiting phytoplankton levels in macrophyte-free waters. With respect to interactions between Daphnia and chlorophyll-a, the results suggest that low macrophyte cover does not result in a reduction of phytoplankton biomass due to the presence of Daphnia. Rather, low macrophyte cover provides a refuge that maintains constant Daphnia predation, so reducing chlorophyll-a fluctuation. These results add credence to the causal interpretation of different interactions amongst nutrients, phytoplankton and zooplankton at very low macrophyte densities.

  14. Remelting of Aluminium by Continuous Submersion of Rolled Scrap

    Energy Technology Data Exchange (ETDEWEB)

    Farner, Snorre

    2000-12-01

    When remelting aluminium scrap, metal losses due to dross generation is a common problem. Reduction of these losses will give substantial economic and environmental benefits. Dross is generated when aluminium metal oxidizes and films of oxide envelope molten metal. When a cold metal object is immersed in a melt, the heat of the melt around this is transferred so rapidly into the object that a shell of melt often solidifies to the surface of the object. When scrap with low bulk density is charged to a melt, solidification of melt on the cold scrap prevents melt from entering the cavities in the bulk of the scrap, and the bulk density remains low. Thus the scrap tends to float on the melt surface. Submersion of this scrap is important to avoid oxidation and subsequent dross generation. One solution to this is to roll scrap to a strip and feed it into the melt. This system has been examined by studying feeding of a continuous, thin aluminium plate into molten aluminium. Also, the effect of lacquer was considered, as well as feeding the plate into a launder with melt flowing along the surface of the plate. An analytical, one-dimensional, steady-state model has been developed to describe the melting and the melting mechanisms. It is based on a shell solidifying on the plate surface and a gap introducing a thermal resistance 1/h{sub g} between the shell and the plate. The thermal resistance 1/h{sub l} of the boundary layer of the melt is included. Depending on these resistances, the initial temperature of the plate and the melt temperature, a shell will form, and the plate will penetrate a distance P into the melt before it melts away. An experimental apparatus was designed and constructed to feed aluminium plate from a coil into a melt bath at a specified velocity. The plate could be withdrawn rapidly to ''freeze'' the situation like it was below the melt surface. The penetration depth P of the plate could be measured and shell formation observed

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

    Science.gov (United States)

    Karmakar, Sukalpa; Mukherjee, Joydeep; Mukherjee, Somnath

    2016-01-01

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

  16. Plant based phosphorus recovery from wastewater via algae and macrophytes.

    Science.gov (United States)

    Shilton, Andrew N; Powell, Nicola; Guieysse, Benoit

    2012-12-01

    At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater. Algal ponds and macrophyte wetlands are already in widespread use for wastewater treatment and if harvested, would require less than one-tenth of the area to recover phosphorus compared to terrestrial crops/pastures. This area could be further decreased if the phosphorus content of the macrophytes and algae biomass was tripled from 1% to 3% via luxury uptake. While this and many other opportunities for plant based recovery of phosphorus exist, e.g. offshore cultivation, much of this technology development is still in its infancy. Research that enhances our understanding of how to maximise phosphorus uptake and harvest yields; and further add value to the biomass for reuse would see the recovery of phosphorus via plants become an important solution in the future. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Influence of the residue from an iron mining dam in the growth of two macrophyte species.

    Science.gov (United States)

    Bottino, F; Milan, J A M; Cunha-Santino, M B; Bianchini, I

    2017-11-01

    On November 5th, 2015 the worst environmental disaster in Brazil spilled 60 million m3 of iron mining residue into Gualaxo do Norte River (Minas Gerais State), an affluent of the highest River Basin of the Brazilian Southeast (Doce River Basin), reaching the Atlantic Ocean. To assess the impact of the iron residue on the aquatic plant metabolism, we performed macrophyte growth experiments under controlled light and temperature conditions using two species (Egeria densa and Chara sp.). The plants' growth data were fitted in a kinetic model to obtain the biomass yields (K) and growth rates (μ). Turbidity and electrical conductivity of the water were measured over time. Both plants showed the highest growth rates in the contaminated condition (0.056 d-1 for E. densa and 0.45 d-1 for Chara sp.) and the biomass increased in the short-term (≈20 days). The control condition (i.e. no impacted water) supported the biomass increasing over time and the development of vegetative buddings with high daily rates (1.75 cm d-1 for E. densa and 0.13 cm d-1 for Chara sp). Turbidity showed a sharp decrease in 48 h and had no effects in the plants growth in the contaminated condition. The contamination affected the plants' yields in the long-term affecting the biomass development. This study provides preliminary information about the ecological consequences of a mining dam rupture aiming to collaborate with monitoring and risk assessments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. vid119_0601d -- Line coverage of sediment types from video collected from the Delta submersible vehicle.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Delta submersible vehicle, outfitted with video equipment (and other devices), was deployed from the R/V Auriga during September 2001 to monitor seafloor...

  20. Submersible Data (Dive Waypoints) for Life on the Edge 2003: Exploring Deep Ocean Habitats - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II at waypoints along its track during two of the seventeen dives of the 2003 "Life on the Edge -...

  1. Submersible Data (Dive Waypoints) for Islands in the Stream 2002 - Pharmaceutical Discovery, Vision, and Bioluminescence - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data and information collected by the submersible Johnson Sea-Link II at waypoints along its track during one dive of the 2002 "Islands in the Stream -...

  2. vid119_0601c-- Point coverage of sediment types from video collected from the Delta submersible vehicle.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Delta submersible vehicle, outfitted with video equipment (and other devices), was deployed from the R/V Auriga during September 2001 to monitor seafloor...

  3. Characterization of clarified medium from submerse and semisolid cultivation of OF Aspergillus awamori NRRL3112 by size-exclusion chromatography

    Directory of Open Access Journals (Sweden)

    MINAMI N.M.

    1999-01-01

    Full Text Available In this study, a preparative size-exclusion chromatography of two different clarified media obtained from submerse and semisolid culture of the mold Aspergillus awamori was carried out. Characterization and comparison of the quantities of glucoamylase and contaminant proteins present in these media were possible. Glucoamylase is the protein with the higher molecular weight in both media analyzed, varying from 72 to 80kDa in the submerse culture and from 68 to 90kDa in the semisolid culture. Also, glucoamylase protein concentration is higher in the submerse culture than in the semisolid culture. The other proteins in the submerse culture presented molecular weights lower than 12kDa and in the semisolid culture their molecular weights varied from 21 to 37kDa and below 10kDa.

  4. vid113_0401p -- Point coverage of sediment types from video collected from the Delta submersible vehicle.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Delta submersible vehicle, outfitted with video equipment (and other devices), was deployed from theR/V Auriga during September 2001 to monitor seafloor...

  5. Assess the environmental health status of macrophyte ecosystems using an oxidative stress biomarker. Case studies: The Gulf of Aqaba and the Lagoon of Venice

    Science.gov (United States)

    Wahsha, Mohammad; Juhmani, Abdul-Salam; Buosi, Alessandro; Sfriso, Andrea; Sfriso, Adriano

    2017-04-01

    Macrophytes play a fundamental role in structuring communities in aquatic environments. They contribute to maintaining the ecosystem services. Unfortunately, nowadays, they are threatened by different sources of pollution. The release of such potentially toxic elements (PTEs) to the environment may influence negatively the ecosystem health, which often limits and sometimes disqualifies the ecosystem biodiversity. Indeed, the increasing concentration and distribution of PTEs in the marine ecosystem by mismanagement of industrial activities, overuse of agrochemicals, and waste disposal are causing worldwide concern. The aim of this work is to describe the developing of an innovative early warning tool, based on the implementation of the lipid peroxidation oxidative stress biomarker for the assessment and monitoring of ecological status in response to PTEs in different marine environments. Six sites were selected along the Jordanian coastline of the Gulf of Aqaba and the lagoon of Venice in Italy according to different morphological, ecological conditions and anthropogenic impact. Our results indicated that the effect of PTEs causes oxidative stress to macrophytes; in particular: Ulva fasciata and Ulva lactuca collected from the lagoon of Venice and Gulf of Aqaba respectively. The oxidative stress by PTEs alters the biochemical processes, as it stimulates the generation of reactive oxygen species (ROS) and accordingly the oxidative degradation of lipids (LPO). The by-products of LPO, the organic compound malondialdehyde (MDA) is significantly correlated (plipid peroxidation.

  6. Submersible pumping, Long Beach Unit of East Wilmington Field: A 17-year review

    Energy Technology Data Exchange (ETDEWEB)

    Allis, D.H.; Capps, W.M.

    1983-10-01

    The electric submersible pump was selected as the primary form of lift when Thums Long Beach Company initiated production operations in August 1965. Deviated wells with ever-increasing volumes resulting from water flooding required a flexibility offered by this method of lift. Numerous problems have been solved in 17 years of these operations to provide a respectable run life and continue on a sound economic operational basis.

  7. Submersible pumping--long beach unit of east wilmington field: A 17-year review

    Energy Technology Data Exchange (ETDEWEB)

    Allis, D.H.; Capps, W.M.

    1984-08-01

    The electric submersible pump (ESP) was selected as the primary form of lift when Thums Long Beach Co. initiated production operations in Aug. 1965. Deviated wells with ever increasing volumes resulting from waterflooding required the flexibility offered by this lift method. Many problems have been solved in the 17 years of these operations to provide a respectable run life and a sound economic operational basis.

  8. Submersible pumping, Long Beach unit of East Wilmington field: a 17-year review

    Energy Technology Data Exchange (ETDEWEB)

    Allis, D.H.; Capps, W.M.

    1983-01-01

    The electric submersible pump was selected as the primary form of lift when THUMS Long Beach Co. initiated production operations in Aug. 1965. Deviated wells with ever-increasing volumes resulting from waterflooding required a flexibility offered by this method of lift. Numerous problems have been solved in 17 yr of these operations to provide a respectable run life and continue on a sound economic operational basis.

  9. Development of a new submersible test to characterise the erosion of soils and sediments

    OpenAIRE

    NDOYE, Ousseynou; Chevalier, Christophe; Reiffsteck, Philippe; MINATCHY, Carlos; FANELLI, Sonia; Pham Van Bang, Damien

    2016-01-01

    Understanding the mechanism and behavior of the scour process is a most challenging subject. One part of this challenge is the in situ measurement of soil and sediment sensitivity to erosion (in undisturbed and submersible conditions). To improve this understanding, a new test, the Wheel Erosion Test (WET), was developed. It consists of a wheel rotating upon a layer of sediments located in an aquarium filled in with water. The rotating speed of the wheel and the distance to the sediment bed a...

  10. Parametric pitch instability investigation of Deep Draft Semi-submersible platform in irregular waves

    OpenAIRE

    Huan Mao; Hezhen Yang

    2016-01-01

    Parametric pitch instability of a Deep Draft Semi-submersible platform (DDS) is investigated in irregular waves. Parametric pitch is a form of parametric instability, which occurs when parameters of a system vary with time and the variation satisfies a certain condition. In previous studies, analyzing of parametric instability is mainly limited to regular waves, whereas the realistic sea conditions are irregular waves. Besides, parametric instability also occurs in irregular waves in some exp...

  11. Dynamic Modeling and Simulation of Deep Geothermal Electric Submersible Pumping Systems

    OpenAIRE

    Julian Kullick; Hackl, Christoph M.

    2017-01-01

    Deep geothermal energy systems employ electric submersible pumps (ESPs) in order to lift geothermal fluid from the production well to the surface. However, rough downhole conditions and high flow rates impose heavy strain on the components, leading to frequent failures of the pump system. As downhole sensor data is limited and often unrealible, a detailed and dynamical model system will serve as basis for deeper understanding and analysis of the overall system behavior. Furthermore, it allows...

  12. Energy consumption behavior of submersible pumps using in the Barind area of Bangladesh

    Science.gov (United States)

    Haque, M. E.; Islam, M. R.; Masud, M. H.; Ferdous, J.; Haniu, H.

    2017-06-01

    In this work the ground water level and water pumping for irrigation and drinking purposes in Barind area of Bangladesh have been studied. The depth of ground water level remains under 30ft throughout the year that enforcing the use of submersible pumps in most parts of Barind zone. The Barind Multipurpose Development Authority (BMDA) and Rajshahi WASA are the major water supplying authority in the Northern Part of Bangladesh by using 14386 and 87 nos of submersible pumps, respectively. An investigation for the values of life cycle cost elements of submersible pumps has also been carried out. The performance of the pumps running in different sites in Barind area were investigated and compared with the lab test results of new pumps. Energy consumption cost is dominating the life cycle cost of the pumps using in Barind region and improper matching of pump standard running conditions and operation/system requirements are the main causes of lower efficiency. It is found that the efficiency of the running pumps is reduced by 20 - 40% than that of lab test results.

  13. Concept of a nuclear powered submersible research vessel and a compact reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kusunoki, Tsuyoshi; Odano, Naoteru; Yoritsune, Tsutomu; Ishida, Toshihisa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Takahashi, Teruo [Energis, Co., Kobe, Hyogo (Japan); Nishimura, Hajime [Japan Marine Science and Technology Center, Yokosuka, Kanagawa (Japan); Tokunaga, Sango [Japan Deep Sea Technology Association, Tokyo (Japan)

    2001-07-01

    A conceptual design study of a submersible research vessel navigating in 600 m depth and a compact nuclear reactor were carried out for the expansion of the nuclear power utilization. The mission of the vessel is the research of mechanism of the climate change to predict the global environment. Through conditions of the Arctic Ocean and the sea at high latitude have significant impacts on the global environmental change, it is difficult to investigate those areas by ordinary ships because of thick ice or storm. Therefore the research vessel is mainly utilized in the Arctic Ocean and the sea at high latitude. By taking account of the research mission, the basic specifications of the vessel are decided; the total weight is 500 t, the submersible depth is 600 m, the maximum speed is 12 knots (22.2 km/h), and the number of crews is 16. Nuclear power has an advantage in supplying large power of electricity in the sea for long period. Based on the requirements, it has been decided that two sets of submersible compact reactor, SCR, which is light-weighted and of enhanced safety characteristics of supply the total electricity of 500 kW. (author)

  14. Parameters structuring macrophyte communities in rivers and lakes – results from a case study in North-Central Poland

    Directory of Open Access Journals (Sweden)

    Szoszkiewicz K.

    2014-01-01

    Full Text Available We analysed macrophyte species composition and abundance, water chemistry and hydromorphological parameters of all major river stretches and lakes in the catchment of the lowland river Wel, Poland. We studied (i which hydromorphological and physico-chemical factors best explained macrophyte species composition, (ii if environmental factors structuring macrophyte communities were different between rivers and lakes; and (iii if macrophyte indices developed to indicate eutrophication correlated with nutrient concentrations. Based on two-way indicator species analysis, correlation analysis and canonical correspondence analysis, we found that river substrate was most important in structuring macrophyte species composition and abundance in rivers, while water quality parameters were most important in lakes; species richness and diversity were correlated with river size and substrate type in rivers, but not in lakes; the relative abundance of macrophyte growth forms was best explained by total organic carbon and Secchi depth in lakes, but it was not correlated with any of the water chemical or hydromorphological parameters in rivers. Irrespective of which factors best explained macrophyte community composition, macrophyte metrics developed to indicate ecological status responded most strongly to total phosphorus concentrations, both in rivers and lakes. We conclude that macrophyte metrics are valuable tools for ecological status assessment also in ecosystems where parameters other than nutrients shape macrophyte community composition.

  15. 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...

  16. Waste water phytodepuration, macrophytes and microphytes nutrient retention; Rassegna di tecniche relative alla depurazione naturale delle acque. Utilizzo di macrofite e microfite nei sistemi di depurazione

    Energy Technology Data Exchange (ETDEWEB)

    Morgana, Jose` Giancarlo; Corazzi, Giulio; Lestini, Marco; Naviglio, Lucia [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1997-07-01

    The traditional systems of water depuration are often responsible of undesirable ecological problems. In fact, the oxidation of pollutants due to standard sewage treatments may induce the overproduction of nutrients. Therefore the wastewater effluents may cause the eutrofication of receiving water bodies. To avoid aftereffects on life conditions of aquatic organisms, nutrient retention based on microphytes and macrophytes abilities is often utilized after traditional sewage treatments. As a matter of fact, in many countries the phytodepuration basins or artificial wetlands have been designed to receive primary and/or secondary wastewater effluents or are used directly for depuration of wastewater of small towns and/or effluents of small industries. In this report they take into account the main biological features of the common techniques of natural water depuration.

  17. Dissolution of copper and iron from automotive brake pad wear debris enhances growth and accumulation by the invasive macrophyte Salvinia molesta Mitchell.

    Science.gov (United States)

    Shupert, Lindsay A; Ebbs, Stephen D; Lawrence, John; Gibson, David J; Filip, Peter

    2013-06-01

    Automotive vehicles release particulate matter into the environment when their brakes are applied. The environmental effects of this automotive brake pad wear debris (BPWD) on the environment is a matter of growing debate yet the effects on plants have been largely untested. In this study, the effect of BPWD on the growth of the aquatic invasive Salvinia molesta Mitchell was examined. Salvinia molesta, plants were grown hydroponically in distilled water or in a distilled water extract containing BPWD. Growth of floating leaves, submerged leaves, and leaf nodes were measured over 20 d at 4-d intervals. At the conclusion of the study the amount of BPWD present in solutions and plant tissues was quantified using atomic absorption spectrometry (AAS). Cultivation of S. molesta in the water containing BPWD resulted in greater dissolution of Cu and Fe than occurred in the absence of plants. The tissue Cu and Fe concentrations of plants cultivated in the BPWD were significantly higher than plants grown in the absence of BPWD. Growth of S. molesta significantly increased when cultivated in the BPWD solutions in comparison to the distilled water. The results suggest that S. molesta and similar aquatic plants may be capable of increasing the dissolution of metal micronutrients from BPWD and utilizing those micronutrients to increase growth. Such growth responses could indicate that BPWD may interact with invasive floating macrophytes to more rapidly degrade the quality and stability of aquatic communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 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

    Directory of Open Access Journals (Sweden)

    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

  19. Effects of litter on substrate conditions and growth of emergent macrophytes

    NARCIS (Netherlands)

    Van der Putten, W.H.; Peters, B.A.M.; Van den Berg, R.S.

    1997-01-01

    Three successive emergent macrophytes (Typha latifolia L., Phragmites australis (Cav.) Steudel and Glyceria maxima (Hartman) Holmbly) were each grown in substrates collected from three different zones of shoreline vegetation development (non- vegetated sediment, the interface between T. latifolia

  20. Seasonal acclimation in the photosynthetic and respiratory temperature responses of three submerged freshwater macrophyte species

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.

    2001-01-01

    Investigations of seasonal temperature acclimation in gas exchange are few and only exist for terrestrial and marine plants. Here we report on results obtained for three freshwater macrophyte species (Callitriche obtusangula, Potamogeton pectinatus and Potamogeton perfoliatus). We collected plants

  1. Macrophyte Community Response to Nitrogen Loading and Thermal Stressors: Water Residence Time Ameliorates Eutrophication Symptom Expression

    Science.gov (United States)

    Empirical determination of nutrient loading thresholds that negatively impact seagrass communities have been elusive due to the multitude of factors involved. Using a mesocosm system that simulated Pacific Northwest estuaries, we evaluated macrophyte metrics across gradients of ...

  2. Interactions between nitrifying and denitrifying bacteria in gnotobiotic microcosms planted with the emergent macrophyte Glyceria maxima

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Duyts, H.; Blom, C.W.P.M.; Laanbroek, H.J.

    1998-01-01

    The population dynamics of the chemolithoautotrophic nitrifiers Nitrosomonas europaea and Nitrobacter winogradskyi were studied in gnotobiotic microcosms fed with ammonium in response to the presence or absence of the emergent macrophyte Glyceria maxima and the heterotrophic denitrifying bacterium

  3. Data for Macrophyte Community Response to Nitrogen Loading and Thermal Stressors in Rapidly Flushed Mesocosm Systems

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data represent response variables from a series of mesocosm experiments to assess how estuarine macrophyte communities respond to nitrogen loading under two...

  4. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

  5. Metal accumulation by submerged macrophytes in eutrophic lakes at the watershed scale.

    Science.gov (United States)

    Xing, Wei; Wu, Haoping; Hao, Beibei; Liu, Guihua

    2013-10-01

    Metal concentrations (Al, Ba, Ca, K, Li, Mg, Na, Se, Sr and Ti) in submerged macrophytes and corresponding water and sediments were studied in 24 eutrophic lakes along the middle and lower reaches of the Yangtze River (China). Results showed that these eutrophic lakes have high metal concentrations in both water and sediments because of human activities. Average concentrations of Al and Na in tissues of submerged macrophytes were very high in sampled eutrophic lakes. By comparison, Ceratophyllum demersum and Najas marina accumulated more metals (e.g. Ba, Ca, K, Mg, Na, Sr and Ti). Strong positive correlations were found between metal concentrations in tissues of submerged macrophytes, probably because of co-accumulation of metals. The concentrations of Li, Mg, Na and Sr in tissues of submerged macrophytes significantly correlated with their corresponding water values, but not sediment values.

  6. Calculation of conversion coefficients using Chinese adult reference phantoms for air submersion and ground contamination.

    Science.gov (United States)

    Lu, Wei; Qiu, Rui; Wu, Zhen; Li, Chunyan; Yang, Bo; Liu, Huan; Ren, Li; Li, Junli

    2017-03-21

    The effective and organ equivalent dose coefficients have been widely used to provide assessment of doses received by adult members of the public and by workers exposed to environmental radiation from nuclear facilities under normal or accidental situations. Advancements in phantom types, weighting factors, decay data, etc, have led to the publication of newer results in this regard. This paper presents a new set of conversion coefficients for air submersion and ground contamination (with the use of Geant4) for photons from 15 keV to 10 MeV using the Chinese and International Commission on Radiological Protection (ICRP) adult reference male and female phantoms. The radiation fields, except for energy spectrum at low energies, were validated by the data obtained from the Monte Carlo code YURI. The effective dose coefficients of monoenergetic photons, obtained for the ICRP adult reference phantoms, agree well with recently published data for air submersion and ground contamination with a plane source at a depth of 0.5 g cm-2 in soil, but an average difference of 36.5% is observed for ground surface contamination with the abovementioned radiation field. The average differences in organ equivalent dose coefficients between the Chinese and the ICRP adult reference phantoms are within 6% for most organs, but noticeable differences of up to 70% or even higher are found at photon energies below 30 keV under air submersion. The effective dose coefficients obtained with the Chinese adult reference phantoms are greater than those of the ICRP adult reference phantoms above 30 keV and 0.5 MeV for ground contamination and air submersion, respectively; the average differences from the Chinese adult reference phantoms are about 3.6% and 0.4% in the whole energy range with maximum differences of 31.8% and 27.6% at 15 keV for air submersion and ground contamination respectively. These differences are attributed to anatomical discrepancies in overlying tissue mass of an

  7. 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.

  8. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in the...

  9. Aquatic Life Criteria - Copper

    Science.gov (United States)

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  10. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  11. Aquatic Life Criterion - Selenium

    Science.gov (United States)

    Documents pertaining to the 2016 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Selenium (Freshwater). These documents include what the safe levels of Selenium are in water for the majority of species.

  12. 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...

  13. Competition between free-floating and submerged macrophytes in a future of climate change

    OpenAIRE

    Netten, J.J.C.

    2011-01-01

    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor mesocosm experiments, a laboratory experiment, a database analysis and a literature review. In Chapter 2a I explored the possibility to use inexpensive open-top chambers (OTCs) as passive artificial warmin...

  14. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  15. Post-remediation use of macrophytes as composting materials for sustainable management of a sanitary landfill.

    Science.gov (United States)

    Song, Uhram

    2017-04-03

    To increase the remediation ability and life expectancy of a leachate channel in a sanitary landfill, the plants used for remediation were composted as a post-remediation management technique. Phragmites australis or Typha angustifolia used for phytoremediation in a landfill leachate channel was harvested and used as a co-composting material with sewage sludge. The macrophyte compost was applied to the slope of a landfill on which plants were introduced for revegetation and to plants grown in pots to test for acute effects of the compost. The compost of the macrophytes successfully increased soil moisture and nutrient contents both on the landfill slope and in the soil of the pot experiment. Additionally, the rates of photosynthesis and the nutrient contents increased for plants grown in macrophyte compost. Thus, the revegetation or restoration management of the landfill would improve with the macrophyte compost used as a soil conditioner. The harvest of the macrophytes has the additional benefit of improving the remediation function of the leachate channel. Therefore, to sustainably manage both the leachate channel and the landfill, the composting of post-remediation macrophytes is an environmentally friendly and economically affordable method.

  16. The influence of macrophytes on sedimentation and nutrient retention in the lower River Spree (Germany).

    Science.gov (United States)

    Schulz, Marcus; Kozerski, Hans-Peter; Pluntke, Thomas; Rinke, Karina

    2003-02-01

    Nutrient retention due to sedimentation in running waters has been little studied. The knowledge about the processes of self-purification is important for the management of rivers. The principal aim of our investigations was to quantify nutrient retention by sedimentation within and adjacent to stands of submerged macrophytes. In addition, we examined the relationship between deposition and sedimentation patterns and the flow regime. In the summer of 2001, investigations were performed in the lower River Spree with sediment traps and sediment cores and measurement of flow velocities. The spatial distribution of macrophytes was described and related to sedimentation and flow patterns. Water and sediment samples were analysed for total phosphorus and total organic nitrogen concentrations. Macrophytes significantly enhanced water residence time by factors between 2 and 18. Trapping rates were high within and downstream of macrophyte stands due to the prevailing quiescent conditions. Trapping rates were low in regions not covered by macrophytes, where flow velocities were high. Calculated deposition of organic matter due to trapping rates accounted for 15-49% of observed deposition between May and September, the vegetation period. The difference between calculated and observed deposition can partly be attributed to an incomplete erosion of the organic sediments between October and April. Between May and September, nitrogen and phosphorus were retained by deposition by as much as 2.5% and 12.2%, respectively (% of total load). Therefore, macrophytes considerably contributed to total monthly phosphorus retention (up to 25%) by increasing deposition of particulate organic matter.

  17. In situ particle characterization and evidence of ubiquitous particle orientation in the ocean using a submersible holographic imaging system (Conference Presentation)

    Science.gov (United States)

    Nayak, Aditya R.; McFarland, Malcolm N.; Stockley, Nicole D.; Twardowski, Michael S.; Sullivan, James M.

    2017-05-01

    Field experiments with the goal of characterizing aquatic particle properties, including size distributions and orientations in their natural environment, were conducted using a submersible holographic imaging system (HOLOCAM). Digital holography is a non-intrusive technique that allows particle fields to be mapped within a 3-D sampling volume at high resolution. The HOLOCAM was deployed at East Sound, a fjord in the US Pacific Northwest, and Lake Erie over three separate deployments from 2013 to 2015. A database of more than a million particles in the 100-10000 µm size range of varying shape and orientation was created after processing holograms. Furthermore, simultaneous, co-located acoustic Doppler velocimeter measurements of small-scale shear and turbulence structure were used to study the effects of the ambient flow field on particle orientation. Several interesting features presented themselves, with a Microcystis bloom dominating the surface layer of Lake Erie, while `thin layers' of high particle concentrations dominated by colonial diatoms were seen in East Sound. Particle size distribution (PSD) slopes in the 50-250 µm size range were 1.7-1.9, while for particles optics as random particle orientation is inherently assumed in theory and models. Preferential alignment can increase/decrease optical properties such as backscattering and attenuation relative to random distributions.

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

    Science.gov (United States)

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

    2016-11-15

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

  19. Submersible UV-Vis spectroscopy for quantifying streamwater organic carbon dynamics: implementation and challenges before and after forest harvest in a headwater stream.

    Science.gov (United States)

    Jollymore, Ashlee; Johnson, Mark S; Hawthorne, Iain

    2012-01-01

    Organic material, including total and dissolved organic carbon (DOC), is ubiquitous within aquatic ecosystems, playing a variety of important and diverse biogeochemical and ecological roles. Determining how land-use changes affect DOC concentrations and bioavailability within aquatic ecosystems is an important means of evaluating the effects on ecological productivity and biogeochemical cycling. This paper presents a methodology case study looking at the deployment of a submersible UV-Vis absorbance spectrophotometer (UV-Vis spectro::lyzer model, s::can, Vienna, Austria) to determine stream organic carbon dynamics within a headwater catchment located near Campbell River (British Columbia, Canada). Field-based absorbance measurements of DOC were made before and after forest harvest, highlighting the advantages of high temporal resolution compared to traditional grab sampling and laboratory measurements. Details of remote deployment are described. High-frequency DOC data is explored by resampling the 30 min time series with a range of resampling time intervals (from daily to weekly time steps). DOC export was calculated for three months from the post-harvest data and resampled time series, showing that sampling frequency has a profound effect on total DOC export. DOC exports derived from weekly measurements were found to underestimate export by as much as 30% compared to DOC export calculated from high-frequency data. Additionally, the importance of the ability to remotely monitor the system through a recently deployed wireless connection is emphasized by examining causes of prior data losses, and how such losses may be prevented through the ability to react when environmental or power disturbances cause system interruption and data loss.

  20. Submersible UV-Vis Spectroscopy for Quantifying Streamwater Organic Carbon Dynamics: Implementation and Challenges before and after Forest Harvest in a Headwater Stream

    Directory of Open Access Journals (Sweden)

    Iain Hawthorne

    2012-03-01

    Full Text Available Organic material, including total and dissolved organic carbon (DOC, is ubiquitous within aquatic ecosystems, playing a variety of important and diverse biogeochemical and ecological roles. Determining how land-use changes affect DOC concentrations and bioavailability within aquatic ecosystems is an important means of evaluating the effects on ecological productivity and biogeochemical cycling. This paper presents a methodology case study looking at the deployment of a submersible UV-Vis absorbance spectrophotometer (UV-Vis spectro::lyzer model, s::can, Vienna, Austria to determine stream organic carbon dynamics within a headwater catchment located near Campbell River (British Columbia, Canada. Field-based absorbance measurements of DOC were made before and after forest harvest, highlighting the advantages of high temporal resolution compared to traditional grab sampling and laboratory measurements. Details of remote deployment are described. High-frequency DOC data is explored by resampling the 30 min time series with a range of resampling time intervals (from daily to weekly time steps. DOC export was calculated for three months from the post-harvest data and resampled time series, showing that sampling frequency has a profound effect on total DOC export. DOC exports derived from weekly measurements were found to underestimate export by as much as 30% compared to DOC export calculated from high-frequency data. Additionally, the importance of the ability to remotely monitor the system through a recently deployed wireless connection is emphasized by examining causes of prior data losses, and how such losses may be prevented through the ability to react when environmental or power disturbances cause system interruption and data loss.

  1. Performance of the macrophyte Lemna valdiviana in tertiary pig waste treatment and its contribution to the sustainability of swine production

    Directory of Open Access Journals (Sweden)

    Flávio R. Lapolli

    2008-03-01

    Full Text Available The present study aims to contribute to the sustainability of swine production by evaluating usage of the aquatic macrophyte Lemna valdiviana in the tertiary treatment of pig waste. Five assays (1 to 5 in triplicate were conducted using swine effluent with different COD (Chemical Oxygen Demand concentrations: 400, 550, 700, 850 and 1,000mg.L-1, respectively. The trial lasted for 21 days and the evaluated variables were: (a pollutant removal efficiency, (b biomass production and (c plant protein content under the different detention times of 7, 14 and 21 days. In general, assays 1 and 2 (CODs of 400 and 550mg.L-1 presented the best removal efficiencies under a detention time of 21 days. Regarding the purpose of both nutrient removal and production of high protein biomass, assay 3 (COD of 700mg.L-1 showed the best results under 14 days’ detention time (36.81% crude protein. It was established that the use of duckweeds in the tertiary swine waste treatment was able to provide a sustainable alternative regarding its advantages such as effluent polishing, minimization of environmental impact, and production of high protein feed.

  2. Analysis of Electric Propulsion Performance on Submersible with Motor DC, Supply Power 10260AH at Voltage 115VDC

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    Indra Ranu Kusuma

    2017-03-01

    Full Text Available Electric propulsion is the ship system using propulsion motor to replace performance of main engine. The application of diesel engine as propulsion system have some problems and weaknesses such as diesel engine unability to operate when submersible vessel is operating under sea. To overcome that problems in submersible vessel, alternative solution of ship propulsion is required. DC Motor can be used as this alternative solution. Submersible vessel use electric propulsion system with DC Motor because DC Motor has advantages of easy rotation setting and does not cause noise when submersible vessel is diving. This bachelor thesis will study the application of DC Motor as an electric propulsion system on submersible vessel with length 59,57 m in series and parallel circuit by simulation using MATLAB software. The simulation data obtained are rotation and torque of DC Motor. From these simulation, it can be concluded that parallel circuit rotation is greater than series circuit rotation. It caused the greater speed and lower power in parallel circuit. 

  3. Donor cornea tissue in cases of drowning or water submersion: eye banks practice patterns and tissue outcomes.

    Science.gov (United States)

    Vijayakumar, Nithya P; Parikh, Purak; Mian, Shahzad I; Tennant, Brad; Grossman, Gregory H; Albrecht, Bob; Niziol, Leslie M; Woodward, Maria A

    2017-10-25

    Surgical use of donor corneal tissue from victims of water submersion (drowning or submersion secondary to death) remains controversial due to limited evidence about the quality of these tissues. To assess the safety of donor corneal tissue from victims of water submersion, an investigation of eye banks' practice patterns and tissue outcomes was conducted. All 79 Eye Bank Association of America accredited eye banks were contacted for a phone interview of practices regarding tissue from victims of water submersion. A retrospective review of corneal tissues from 2014 to 2016 from a large eye bank network was performed to identify all donors submerged in water. Corneal epithelial integrity, endothelial cell density (ECD), rim cultures, and adverse events were analyzed for associations with water submersion characteristics. 49 eye banks (62% response) participated in the survey. 55% of these eye banks had specific, written protocol for tissue eligibility from donors submerged in water. With or without specific protocol, eye banks reported considering water type (84%) and length of time submerged (92%) to determine eligibility. 22% of eye banks reported medical director involvement when eligibility determination was unclear. 79 tissues from 40 donors who were submerged were identified in 2014-2016 eye bank data. No donor tissues had pre-processing corneal infiltrates, positive rim cultures, or adverse events post-keratoplasty. Corneal epithelial integrity and ECD were not associated with water type or length of time submerged. In conclusion, data from a large eye bank network showed no adverse events or outcomes, indicating these tissues may be safe.

  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. Modeling the interaction between flow and highly flexible aquatic vegetation

    Science.gov (United States)

    Dijkstra, J. T.; Uittenbogaard, R. E.

    2010-12-01

    Aquatic vegetation has an important role in estuaries and rivers by acting as bed stabilizer, filter, food source, and nursing area. However, macrophyte populations worldwide are under high anthropogenic pressure. Protection and restoration efforts will benefit from more insight into the interaction between vegetation, currents, waves, and sediment transport. Most aquatic plants are very flexible, implying that their shape and hence their drag and turbulence production depend on the flow conditions. We have developed a numerical simulation model that describes this dynamic interaction between very flexible vegetation and a time-varying flow, using the sea grass Zostera marina as an example. The model consists of two parts: an existing 1DV k-ɛ turbulence model simulating the flow combined with a new model simulating the bending of the plants, based on a force balance that takes account of both vegetation position and buoyancy. We validated this model using observations of positions of flexible plastic strips and of the forces they are subjected to, as well as hydrodynamic measurements. The model predicts important properties like the forces on plants, flow velocity profiles, and turbulence characteristics well. Although the validation data are limited, the results are sufficiently encouraging to consider our model to be of generic value in studying flow processes in fields of flexible vegetation.

  6. Life cycle impacts of topsoil erosion on aquatic ecosystems: case study on Eucalyptus globulus forest

    Science.gov (United States)

    Quinteiro, Paula; Van de Broek, Marijn; Cláudia Dias, Ana; Ridoutt, Bradley; Arroja, Luís

    2016-04-01

    High concentrations of suspended solids (SS), particularly in the clay and silt size fractions, reaching lotic environments and remaining in suspension can be a significant stressors to the biodiversity of these aquatic systems, degrading the water quality and directly affecting the aquatic biota, namely macroinvertebrates, algae and macrophytes. This damage is presently not considered in Life Cycle Assessment studies. This study is devoted to the effects of SS into freshwater systems due to topsoil erosion by water (environmental mechanism), translated into damage to aquatic ecosystem diversity (endpoint impact category), namely to macroinvertebrates, algae and macrophytes. For this, we have developed a framework to conduct an erosion inventory using the WaTEM/SEDEM model and linked this with, a method to derive regional characterisation for endpoint damage on aquatic ecosystem diversity. A case study was performed for Eucalyptus globulus stands in Portugal, with a functional unit of one hectare of land under production forestry management. To demonstrate how this newly SS ecosystem method can help to improve the environmental assessment in forestry, results were compared with the earlier commonly used impact categories from ReCiPe method. The relevance of the impact from SS delivery to freshwater streams is shown, providing a more comprehensive assessment of the SS impact from land use systems on aquatic environments. The SS impacts ranged from 15.5 to 1234.9 PDF.m3.yr.ha-1.revolution-1 for macroinvertebrates, and from 5.2 to 411.9 PDF.m3.yr.ha-1.revolution-1 for algae and macrophytes. For some stands, SS potential impacts on macroinvertebrates have the same order of magnitude than freshwater eutrophication, freshwater ecotoxicity, terrestrial ecotoxicity and terrestrial acidification impacts. For algae and macrophytes, most of the stands present SS impacts of the same order of magnitude as terrestrial ecotoxicity, one order of magnitude higher than freshwater

  7. Study on global performances and mooring-induced damping of a semi-submersible

    Science.gov (United States)

    Xiong, Ling-zhi; Yang, Jian-min; Lv, Hai-ning; Zhao, Wen-hua; Kou, Yu-feng

    2016-10-01

    The harsh environmental conditions bring strong nonlinearities to the hydrodynamic performances of the offshore floating platforms, which challenge the reliable prediction of the platform coupled with the mooring system. The present study investigates a typical semi-submersible under both the operational and the survival conditions through numerical and experimental methods. The motion responses, the mooring line tensions, and the wave loads on the longitudinal mid-section are investigated by both the fully non-linearly coupled numerical simulation and the physical experiment. Particularly, in the physical model test, the wave loads distributed on the semi-submersible's mid-section were measured by dividing the model into two parts, namely the port and the starboard parts, which were rigidly connected by three six-component force transducers. It is concluded that both the numerical and physical model can have good prediction of the semi-submersible's global responses. In addition, an improved numerical approach is proposed for the estimation of the mooring-induced damping, and is validated by both the experimental and the published results. The characteristics of the mooring-induced damping are further summarized in various sea states, including the operational and the survival environments. In order to obtain the better prediction of the system response in deep water, the mooring-induced damping of the truncated mooring lines applied in the physical experiment are compensated by comparing with those in full length. Furthermore, the upstream taut and the downstream slack mooring lines are classified and investigated to obtain the different mooring line damping performances in the comparative study.

  8. Monitoring the effects of floods on submerged macrophytes in a large river.

    Science.gov (United States)

    Ibáñez, Carles; Caiola, Nuno; Rovira, Albert; Real, Montserrat

    2012-12-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton to a macrophyte-dominated system. Macrophytes started to spread at the end of the 1990s and since 2002 artificial floods (flushing flows) of short duration (1-2 days) are released from the Riba-roja dam once or twice a year in order to reduce macrophyte density. The aim of this study was to analyse the spatiotemporal trends of the submerged macrophytes in two stretches of the lower Ebro River using high-resolution hydroacoustic methods, in order to elucidate the effects of artificial floods and natural floods on its distribution and abundance. Results showed that the mean cover in the two studied stretches (Móra and Ginestar) was not reduced after a flushing flow (from 36.59% to 55.85% in Móra, and from 21.18% to 21.05% in Ginestar), but it was greatly reduced after the natural flood (down to 9.79% in Móra and 2.04% in Ginestar); surprisingly the cover increased in Móra after the artificial flood. In order to increase the efficiency of floods in controlling macrophyte spreading, the magnitude and frequency of them should largely increase, as well as the suspended sediment load, approaching as much as possible to the original flood pattern before dam construction. Hydroacoustic methods combined with geostatistics and interpolation in GIS can accurately monitor spatiotemporal trends of submerged macrophytes in large rivers. This is the first article to apply this monitoring system to submerged macrophytes in rivers. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. INTENSITY SETTER FOR A DEVICE OF SMOOTH START OF SUBMERSIBLE PUMP ELECTRIC MOTOR

    Directory of Open Access Journals (Sweden)

    V.I. Lobov

    2016-06-01

    Full Text Available Purpose. Development of an intensity setter, which in a rational law changes the opening thyristor the voltage regulator and effectively to changing power supply voltage stator windings of the electric pump deepening, ensuring a smooth start in a wide range. Methodology. Electric submersible pump belongs to the small inertia electric, since it is not significant total moment of inertia, not exceeding two moments of inertia of the motor and static moment on the shaft does not exceed forty percent of the nominal torque. For technical requirements that electric acceleration time should have no less than twenty seconds or more. Office starting modes of electric submersible pumps economically justified using thyristor voltage regulator by forming the dial changes the intensity of the necessary legislation in time voltage feeding the stator windings. This ensures a smooth start right rotor of the electric submersible pump. Results. A block diagram of the intensity setter that is: with control unit, two units that form the exponential voltage supply emitter follower and regulatory elements. The mathematical expressions for voltage at the stator windings of the motor, changing exponentially, opening the angle of thyristor power unit thyristor the voltage regulator, which is determined through the initial angle of opening. Provided formula for pick-up voltage and minimum voltage, time constants, which are determined from the basic equations of motion and mechanical characteristics of the electric motor. Analytical investigated by the voltage dependence violation by changing the time constant flowing and growing exhibitor supply voltage stator electric circuit deepening pump. Originality. Proposed in the initial time on the stator windings of the electric pick-up voltage is applied. Under the influence of this voltage, motor rotor begins to accelerate. At the same time, pick-up voltage decreases the minimum startup voltage varies exponentially in which

  10. Maintenance of submersible pumps in the septic tanks: ergonomic and biological risks to the worker.

    Science.gov (United States)

    Mariño, Suzi; Figueiredo, Alex

    2012-01-01

    In this study was observed the maintenance task of submersible pumps septic tanks installed in industrial bathrooms. This maintenance activity operators are exposed to various biological and ergonomic risks. This type of activity requires its great physical performers who are also subject to contact with human waste in the form of liquids, gases and solids. Besides the problems mentioned, are still exposed to high temperatures that can cause diseases such as hyperthermia or heatstroke. These aspects were observed using the ergonomic assessment methodology in order to suggest improvements that are reflected in productivity and employee satisfaction.

  11. A study among the population of Sevilla of death due to submersion.

    Science.gov (United States)

    Gamero, J; Romero, J L; Arufe, M I; Vizcaya, M A; Balanza, E

    1997-03-01

    Death due to submersion is of great interest from the medical-legal point of view, given the increase in nautical activity among children and adults alike over the past number of years. However, the lack of reliable statistical data concerning the impact of this specific form of death in our country must be emphasized. These are the circumstances that have led us to study the incidence of this form of death in a specific area. The population analyzed lived in the city of Sevilla during the period 1967-1993.

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

    Science.gov (United States)

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

    2012-03-10

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

  13. 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

  14. BIO-MONITORING FOR URANIUM USING STREAM-SIDE TERRESTRIAL PLANTS AND MACROPHYTES

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, E.; Duff, M.; Hicks, T.; Coughlin, D.; Hicks, R.; Dixon, E.

    2012-01-12

    This study evaluated the abilities of various plant species to act as bio-monitors for environmental uranium (U) contamination. Vegetation and soil samples were collected from a U processing facility. The water-way fed from facility storm and processing effluents was the focal sample site as it represented a primary U transport mechanism. Soils and sediments from areas exposed to contamination possessed U concentrations that averaged 630 mg U kg{sup -1}. Aquatic mosses proved to be exceptional accumulators of U with dry weight (dw) concentrations measuring as high as 12500 mg U kg{sup -1} (approximately 1% of the dw mass was attributable to U). The macrophytes (Phragmites communis, Scripus fontinalis and Sagittaria latifolia) were also effective accumulators of U. In general, plant roots possessed higher concentrations of U than associated upper portions of plants. For terrestrial plants, the roots of Impatiens capensis had the highest observed levels of U accumulation (1030 mg kg{sup -1}), followed by the roots of Cyperus esculentus and Solidago speciosa. The concentration ratio (CR) characterized dry weight (dw) vegetative U levels relative to that in associated dw soil. The plant species that accumulated U at levels in excess of that found in the soil were: P. communis root (CR, 17.4), I. capensis root (CR, 3.1) and S. fontinalis whole plant (CR, 1.4). Seven of the highest ten CR values were found in the roots. Correlations with concentrations of other metals with U were performed, which revealed that U concentrations in the plant were strongly correlated with nickel (Ni) concentrations (correlation: 0.992; r-squared: 0.984). Uranium in plant tissue was also strongly correlated with strontium (Sr) (correlation: 0.948; r-squared: 0.899). Strontium is chemically and physically similar to calcium (Ca) and magnesium (Mg), which were also positively-correlated with U. The correlation with U and these plant nutrient minerals, including iron (Fe), suggests that active

  15. 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.

  16. Experimental Problems of New Constructions of Portable Submersible Pumps for Mining with Electric Motor Cooled by Water Jacket

    Directory of Open Access Journals (Sweden)

    Andrzej KORCZAK

    2014-12-01

    Full Text Available The article presents a new construction of a submersible pumping engine where new original solutions in flowing system and control system where introduced It let obtain high efficiency and fulfill user’s expectations. The article also contains experiments of the new pumping engine and their results. The results of numerical analysis of the movement of liquid in flowing channel is described and the analytical characteristics are compared with ones measured in laboratory. The work also presents the problems with constructing, research and certification of new submersible pumping engine which construction fulfils ATEX requirements for machines working in explosive conditions areas

  17. Large herbivores and aquatic-terrestrial links in southern boreal forests.

    Science.gov (United States)

    Bump, Joseph K; Tischler, Keren B; Schrank, Amy J; Peterson, Rolf O; Vucetich, John A

    2009-03-01

    1. Concurrent measurement of population dynamics and associated spatio-temporal patterns of resource flow across aquatic-terrestrial boundaries are rare, yet necessary to understand the consequences of cross-habitat resource flux. Long-term study of the moose Alces alces (L.) population in Isle Royale National Park (Lake Superior, USA) provides an opportunity to examine the patterns of resource flux from aquatic to terrestrial habitats over approximately50 years. 2. We analysed the spatio-temporal dynamics of aquatic-derived nitrogen (N) that moose transfer to terrestrial systems by using excretion models, foraging parameters, moose densities, and moose carcass locations (n = 3616) collected from 1958-2005. 3. Results suggest that moose transfer significant amounts of aquatic-derived N to terrestrial systems, which likely increases terrestrial N availability in riparian zones. A seasonal increase in terrestrial N availability when moose are foraging on N-rich aquatic macrophytes would contrast with the depression of soil N mineralization previously attributed indirectly to moose. 4. Aquatic foraging by moose and moose carcass locations are significantly clustered at multiple scales, indicating that grey wolves Canis lupus (L.) and moose can create concentrated areas of resource transfer due to clustered predation and foraging patterns. 5. This study shows that patterns of faunal-mediated resource transfer can depend significantly on predator-prey dynamics, and that large predators in this system influence herbivore-controlled resource transfer between ecosystems. Given the circumpolar extent of moose, they constitute an important, unquantified aquatic-terrestrial resource vector in boreal systems.

  18. Macrophytes, epipelic biofilm, and invertebrates as biotic indicators of physical habitat degradation of lowland streams (Argentina).

    Science.gov (United States)

    Cortelezzi, Agustina; Sierra, María Victoria; Gómez, Nora; Marinelli, Claudia; Rodrigues Capítulo, Alberto

    2013-07-01

    Our objective was to assess the effect of the physical habitat degradation in three lowland streams of Argentina that are subject to different land uses. To address this matter, we looked into some physical habitat alterations, mainly the water quality and channel changes, the impact on macrophytes' community, and the structural and functional descriptors of the epipelic biofilm and invertebrate assemblages. As a consequence of physical and chemical perturbations, we differentiated sampling sites with different degradation levels. The low degraded sites were affected mainly for the suburban land use, the moderately degraded sites for the rural land use, and the highly degraded sites for the urban land use. The data shows that the biotic descriptors that best reflected the environmental degradation were vegetation cover and macrophytes richness, the dominance of tolerant species (epipelic biofilm and invertebrates), algal biomass, O2 consumption by the epipelic biofilm, and invertebrates' richness and diversity. Furthermore, the results obtained highlight the importance of the macrophytes in the lowland streams, where there is a poor diversification of abiotic substrates and where the macrophytes not only provide shelter but also a food source for invertebrates and other trophic levels such as fish. We also noted that both in benthic communities, invertebrates and epipelic biofilm supplied different information: the habitat's physical structure provided by the macrophytes influenced mainly the invertebrate descriptors; meanwhile, the water quality mainly influenced most of the epipelic biofilm descriptors.

  19. Enhanced effects of biotic interactions on predicting multispecies spatial distribution of submerged macrophytes after eutrophication.

    Science.gov (United States)

    Song, Kun; Cui, Yichong; Zhang, Xijin; Pan, Yingji; Xu, Junli; Xu, Kaiqin; Da, Liangjun

    2017-10-01

    Water eutrophication creates unfavorable environmental conditions for submerged macrophytes. In these situations, biotic interactions may be particularly important for explaining and predicting the submerged macrophytes occurrence. Here, we evaluate the roles of biotic interactions in predicting spatial occurrence of submerged macrophytes in 1959 and 2009 for Dianshan Lake in eastern China, which became eutrophic since the 1980s. For the four common species occurred in 1959 and 2009, null species distribution models based on abiotic variables and full models based on both abiotic and biotic variables were developed using generalized linear model (GLM) and boosted regression trees (BRT) to determine whether the biotic variables improved the model performance. Hierarchical Bayesian-based joint species distribution models capable of detecting paired biotic interactions were established for each species in both periods to evaluate the changes in the biotic interactions. In most of the GLM and BRT models, the full models showed better performance than the null models in predicting the species presence/absence, and the relative importance of the biotic variables in the full models increased from less than 50% in 1959 to more than 50% in 2009 for each species. Moreover, co-occurrence correlation of each paired species interaction was higher in 2009 than that in 1959. The findings suggest biotic interactions that tend to be positive play more important roles in the spatial distribution of multispecies assemblages of macrophytes and should be included in prediction models to improve prediction accuracy when forecasting macrophytes' distribution under eutrophication stress.

  20. New insights on the species-specific allelopathic interactions between macrophytes and marine HAB dinoflagellates.

    Science.gov (United States)

    Ben Gharbia, Hela; Kéfi-Daly Yahia, Ons; Cecchi, Philippe; Masseret, Estelle; Amzil, Zouher; Herve, Fabienne; Rovillon, Georges; Nouri, Habiba; M'Rabet, Charaf; Couet, Douglas; Zmerli Triki, Habiba; Laabir, Mohamed

    2017-01-01

    Macrophytes are known to release allelochemicals that have the ability to inhibit the proliferation of their competitors. Here, we investigated the effects of the fresh leaves of two magnoliophytes (Zostera noltei and Cymodocea nodosa) and thalli of the macroalgae Ulva rigida on three HAB-forming benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis). The effects of C. nodosa and U. rigida were also tested against the neurotoxic planktonic dinoflagellate Alexandrium pacificum Litaker sp. nov (former Alexandrium catenella). Co-culture experiments were conducted under controlled laboratory conditions and potential allelopathic effects of the macrophytes on the growth, photosynthesis and toxin production of the targeted dinoflagellates were evaluated. Results showed that U. rigida had the strongest algicidal effect and that the planktonic A. pacificum was the most vulnerable species. Benthic dinoflagellates seemed more tolerant to potential allelochemicals produced by macrophytes. Depending on the dinoflagellate/macrophyte pairs and the weight of leaves/thalli tested, the studied physiological processes were moderately to heavily altered. Our results suggest that the allelopathic activity of the macrophytes could influence the development of HAB species.