Emergent macrophytes modify the abundance and community composition of ammonia oxidizers in their rhizosphere sediments.

Science.gov (United States)

Zhao, Dayong; He, Xiaowei; Huang, Rui; Yan, Wenming; Yu, Zhongbo

2017-07-01

Ammonia oxidation is a crucial process in global nitrogen cycling, which is catalyzed by the ammonia oxidizers. Emergent plants play important roles in the freshwater ecosystem. Therefore, it is meaningful to investigate the effects of emergent macrophytes on the abundance and community composition of ammonia oxidizers. In the present study, two commonly found emergent macrophytes (Zizania caduciflora and Phragmitas communis) were obtained from freshwater lakes and the abundance and community composition of the ammonia-oxidizing prokaryotes in the rhizosphere sediments of these emergent macrophytes were investigated. The abundance of the bacterial amoA gene was higher in the rhizosphere sediments of the emergent macrophytes than those of bulk sediments. Significant positive correlation was found between the potential nitrification rates (PNRs) and the abundance of bacterial amoA gene, suggesting that ammonia-oxidizing bacteria (AOB) might play an important role in the nitrification process of the rhizosphere sediments of emergent macrophytes. The Nitrosotalea cluster is the dominant ammonia-oxidizing archaea (AOA) group in all the sediment samples. Analysis of AOB group showed that the N. europaeal cluster dominated the rhizosphere sediments of Z. caduciflora and the bulk sediments, whereas the Nitrosospira cluster was the dominant AOB group in the rhizosphere sediments of P. communis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Science.gov (United States)

Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

2016-01-01

Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions. PMID:26735689

Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Science.gov (United States)

Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

2016-01-01

Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

Directory of Open Access Journals (Sweden)

Mo-Zhu Wang

Full Text Available Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

Flow controls on lowland river macrophytes: a review.

Science.gov (United States)

Franklin, Paul; Dunbar, Michael; Whitehead, Paul

2008-08-01

We review the current status of knowledge regarding the role that flow parameters play in controlling the macrophyte communities of temperate lowland rivers. We consider both direct and indirect effects and the interaction with other factors known to control macrophyte communities. Knowledge gaps are identified and implications for the management of river systems considered. The main factors and processes controlling the status of macrophytes in lowland rivers are velocity (hence also discharge), light, substrate, competition, nutrient status and river management practices. We suggest that whilst the characteristics of any particular macrophyte community reflect the integral effects of a combination of the factors, fundamental importance can be attributed to the role of discharge and velocity in controlling instream macrophyte colonisation, establishment and persistence. Velocity and discharge also appear to control the relative influence of some of the other controlling factors. Despite the apparent importance of velocity in determining the status of macrophyte communities in lowland rivers, relatively little is understood about the nature of the processes controlling this relationship. Quantitative knowledge is particularly lacking. Consequently, the ability to predict macrophyte abundance and distribution in rivers is still limited. This is further complicated by the likely existence of feedback effects between the growth of macrophytes and velocity. Demand for water resources increases the pressure on lowland aquatic ecosystems. Despite growing recognition of the need to allocate water for the needs of instream biota, the inability to assess the flow requirements of macrophyte communities limits the scope to achieve this. This increases the likelihood of overexploitation of the water resource as other users, whose demands are quantifiable, are prioritised.

The effects of artificial sandbar breaching on the macrophyte communities of an intermittently open estuary

Science.gov (United States)

Ribeiro, Jose Pedro N.; Saggio, Ângelo; Lima, Maria Inês Salgueiro

2013-04-01

Artificial sandbar opening of intermittently open estuaries is a practice utilised worldwide to improve water quality, fishing, and recreational amenities and to prevent the flooding of adjacent properties. Breaching causes the water level to drop drastically, exposing plants to two water level extremes. With some exceptions, estuarine communities are adversely affected by this practice. Although breaching can happen naturally, artificial breaching is on the rise, and the impact of manipulating water levels on estuarine communities needs to be investigated. In this work, we described the breaching cycles of the Massaguaçu River Estuary and proposed flooding scenarios for the estuary's macrophyte banks based on our data. We calculated the relationship between plant distribution and flooding conditions and used our calculations to predict the estuary community's composition depending on the water level at breaching time. We discovered a strong relationship between plant distribution and flooding conditions, and we predicted that the estuarine community would be markedly different between flooding scenarios. Low frequency flooding scenarios would be related to submerged macrophytes and, as the flooding frequency increases, macrophytes would be replaced by amphibious plants, and eventually by the arboreal stratus. Therefore, we concluded that an increase in artificial breaching cycles would have a detrimental impact on the estuary community.

Deterioration of atlantic soft water macrophyte communities by acidification, eutrophication and alkalinisation

NARCIS (Netherlands)

Arts, G.H.P.

2002-01-01

This review presents an overview of the most important succession patterns and underlying processes associated with the deterioration of soft water macrophyte communities in atlantic and boreo-atlantic regions. As acidification, eutrophication and alkalinisation are the dominant processes, this

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

2018-02-01

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 characterised 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 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.

Predicting Changes in Macrophyte Community Structure from Functional Traits in a Freshwater Lake: A Test of Maximum Entropy Model

Science.gov (United States)

Fu, Hui; Zhong, Jiayou; Yuan, Guixiang; Guo, Chunjing; Lou, Qian; Zhang, Wei; Xu, Jun; Ni, Leyi; Xie, Ping; Cao, Te

2015-01-01

Trait-based approaches have been widely applied to investigate how community dynamics respond to environmental gradients. In this study, we applied a series of maximum entropy (maxent) models incorporating functional traits to unravel the processes governing macrophyte community structure along water depth gradient in a freshwater lake. We sampled 42 plots and 1513 individual plants, and measured 16 functional traits and abundance of 17 macrophyte species. Study results showed that maxent model can be highly robust (99.8%) in predicting the species relative abundance of macrophytes with observed community-weighted mean (CWM) traits as the constraints, while relative low (about 30%) with CWM traits fitted from water depth gradient as the constraints. The measured traits showed notably distinct importance in predicting species abundances, with lowest for perennial growth form and highest for leaf dry mass content. For tuber and leaf nitrogen content, there were significant shifts in their effects on species relative abundance from positive in shallow water to negative in deep water. This result suggests that macrophyte species with tuber organ and greater leaf nitrogen content would become more abundant in shallow water, but would become less abundant in deep water. Our study highlights how functional traits distributed across gradients provide a robust path towards predictive community ecology. PMID:26167856

Macrophyte Communities of Andean Rivers: Composition and Relation with Environmental Factors

OpenAIRE

Alida Marcela Gómez Rodríguez; Luz Teresa Valderrama Valderrama; Carlos A. Rivera-Rondón

2017-01-01

Small streams of tropical Andes have been poorly studied. Therefore, there is little information about the structure, dynamics and function of their macrophyte communities. In this research, aquatic plant communities of 18 Andean streams of La Vieja (Quindío) and Otún (Risaralda) river basins were studied; those are some of the basins most affected by anthropic activities in the country. Streams were selected according to their association with the main land’s uses of the region in both basin...

Multivariate Analysis of Water Quality and Benthic Macrophyte Communities in Florida Bay, USA Reveals Hurricane Effects and Susceptibility to Seagrass Die-Off

Directory of Open Access Journals (Sweden)

Amanda M. Cole

2018-05-01

Full Text Available Seagrass communities, dominated by Thalassia testudinum, form the principal benthic ecosystem within Florida Bay, Florida USA. The bay has had several large-scale seagrass die-offs in recent decades associated with drought and hypersaline conditions. In addition, three category-5 hurricanes passed in close proximity to the bay during the fall of 2005. This study investigated temporal and spatial trends in macrophyte abundance and water quality from 2006 to 2013 at 15 permanent transect sites, which were co-located with long-term water quality stations. Relationships, by year and by transect location (basin, between antecedent water quality (mean, minimum and maximum for a 6-month period and benthic macrophyte communities were examined using multivariate analyses. Total phosphorus, salinity, pH, turbidity, dissolved inorganic nitrogen (DIN, DIN to phosphate ratio (DIN:PO4-3, chlorophyll a, and dissolved oxygen correlated with temporal and spatial variations in the macrophyte communities. Temporal analysis (MDS and LINKTREE indicated that the fall 2005 hurricanes affected both water quality and macrophyte communities for approximately a 2-year period. Spatial analysis revealed that five basins, which subsequently exhibited a major seagrass die-off during summer 2015, significantly differed from the other ten basins in macrophyte community structure and water quality more than 2 years before this die-off event. High total phosphorus, high pH, low DIN, and low DIN:PO4-3, in combination with deep sediments and high seagrass cover were characteristic of sites that subsequently exhibited severe die-off. Our results indicate basins with more mixed seagrass communities and higher macroalgae abundance are less susceptible to die-off, which is consistent with the management goals of promoting more heterogeneous benthic macrophyte communities.

Food choice effects on herbivory: Intra-specific seagrass palatability and inter-specific macrophyte palatability in seagrass communities

Science.gov (United States)

Jiménez-Ramos, Rocío; Brun, Fernando G.; Egea, Luis G.; Vergara, Juan J.

2018-05-01

Interactions between the palatability and abundance of different food sources may influence herbivory patterns in seagrass-dominated communities. In addition, intra-specific differences in nutrient and structural quality of leaves may also alter seagrass palatability and generate different rates of consumption within these communities. We offered two temperate seagrasses species, (Cymodocea nodosa and Zostera noltei) from two different locations to look at intraspecific differences, and two other macrophytes, both of which occur at the same location as seagrasses but represent the extremes of palatability, to a generalist herbivore Paracentrotus lividus (purple sea urchin). Using feeding assays, we compared the consumption rates in individual (single plant species) and combined diets at different food availabilities. Intra-specific differences between seagrass species growing at different locations (inner and outer bay) were indeed found to significantly modify the consumption rate for one species. Structural traits such as carbon content were linked to the low consumption found in Cymodocea nodosa from the inner bay location. In addition, we found that the co-occurrence of different macrophyte species can result in preferential consumption of the more palatable macrophyte with high nutritional content and low structural defence over seagrasses, especially when P. lividus has an abundant food supply. Overall, our findings suggest that intra- and inter-specific differences in seagrass traits and the relative abundance of other macrophytes may explain the variability in patterns of herbivory found within seagrass communities.

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...

Phylogenetically diverse macrophyte community promotes species diversity of mobile epi-benthic invertebrates

Science.gov (United States)

Nakamoto, Kenta; Hayakawa, Jun; Kawamura, Tomohiko; Kodama, Masafumi; Yamada, Hideaki; Kitagawa, Takashi; Watanabe, Yoshiro

2018-07-01

Various aspects of plant diversity such as species diversity and phylogenetic diversity enhance the species diversity of associated animals in terrestrial systems. In marine systems, however, the effects of macrophyte diversity on the species diversity of associated animals have received little attention. Here, we sampled in a subtropical seagrass-seaweed mixed bed to elucidate the effect of the macrophyte phylogenetic diversity based on the taxonomic relatedness as well as the macrophyte species diversity on species diversity of mobile epi-benthic invertebrates. Using regression analyses for each macrophyte parameter as well as multiple regression analyses, we found that the macrophyte phylogenetic diversity (taxonomic diversity index: Delta) positively influenced the invertebrate species richness and diversity index (H‧). Although the macrophyte species richness and H‧ also positively influenced the invertebrate species richness, the best fit model for invertebrate species richness did not include them, suggesting that the macrophyte species diversity indirectly influenced invertebrate species diversity. Possible explanations of the effects of macrophyte Delta on the invertebrate species diversity were the niche complementarity effect and the selection effect. This is the first study which demonstrates that macrophyte phylogenetic diversity has a strong effect on the species diversity of mobile epi-benthic invertebrates.

Assessing Environmental Impact on Aquatic Macrophyte Species ...

African Journals Online (AJOL)

Impact of environmental variables on distribution and composition of aquatic macrophyte community in a tropical river was assessed for one year (March 2009 to February 2010). Hypothesis tested was that the spatial variation in environmental variables on the river's longitudinal gradient affects macrophyte species ...

The role of pH in structuring communities of Maine wetland macrophytes and chironomid larvae (Diptera)

Science.gov (United States)

Woodcock, T.S.; Longcore, J.R.; McAuley, D.G.; Mingo, T.M.; Bennatti, C.R.; Stromborg, K.L.

2005-01-01

Aquatic vascular plants, or macrophytes, are an important habitat component for many wetland organisms, and larvae of chironomid midges are ubiquitous components of wetland fauna. Many chironomids are primary consumers of algae and detritus and form an essential energetic link between allochthonous and autochthonous primary production and higher trophic levels, while others are predators and feed on smaller invertebrates. Live macrophytes serve mostly as habitat, whereas plant detritus serves as both habitat and as a food source. Assemblages of macrophytes and chironomid larvae were surveyed in ten Maine wetlands, five with low pH (5.5), and explained in terms of physical and chemical habitat variables. Macrophyte richness was significantly greater, and richness of chironomid larvae was lower, in low pH wetlands. There was no difference in chironomid abundance related to pH. However, community structure was related to pH, suggesting that competitive dominance of a few taxa was responsible for lower richness in low pH wetlands, whereas competition was weaker in high pH wetlands, making coexistence of more chironomid taxa possible. An examination of individual chironomid taxa by stepwise multiple regression showed that distribution of most taxa was controlled by water chemistry variables and macrophyte habit (i.e., floating, submergent).

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...

Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes

Science.gov (United States)

Hilt, Sabine; Alirangues Nuñez, Marta M.; Bakker, Elisabeth S.; Blindow, Irmgard; Davidson, Thomas A.; Gillefalk, Mikael; Hansson, Lars-Anders; Janse, Jan H.; Janssen, Annette B. G.; Jeppesen, Erik; Kabus, Timm; Kelly, Andrea; Köhler, Jan; Lauridsen, Torben L.; Mooij, Wolf M.; Noordhuis, Ruurd; Phillips, Geoff; Rücker, Jacqueline; Schuster, Hans-Heinrich; Søndergaard, Martin; Teurlincx, Sven; van de Weyer, Klaus; van Donk, Ellen; Waterstraat, Arno; Willby, Nigel; Sayer, Carl D.

2018-01-01

Submerged macrophytes play a key role in north temperate shallow lakes by stabilizing clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analyzed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterized by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterized by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative

Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes.

Science.gov (United States)

Hilt, Sabine; Alirangues Nuñez, Marta M; Bakker, Elisabeth S; Blindow, Irmgard; Davidson, Thomas A; Gillefalk, Mikael; Hansson, Lars-Anders; Janse, Jan H; Janssen, Annette B G; Jeppesen, Erik; Kabus, Timm; Kelly, Andrea; Köhler, Jan; Lauridsen, Torben L; Mooij, Wolf M; Noordhuis, Ruurd; Phillips, Geoff; Rücker, Jacqueline; Schuster, Hans-Heinrich; Søndergaard, Martin; Teurlincx, Sven; van de Weyer, Klaus; van Donk, Ellen; Waterstraat, Arno; Willby, Nigel; Sayer, Carl D

2018-01-01

Submerged macrophytes play a key role in north temperate shallow lakes by stabilizing clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analyzed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterized by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterized by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative

Submerged macrophyte communities in the Forsmark area. Building of a GIS application as a tool for biomass estimations

International Nuclear Information System (INIS)

Fredriksson, Ronny

2005-12-01

The aim of this study was to compile the information from previous studies to produce a GIS application that both illustrates the distribution of different vegetation communities and also makes it possible to estimate the total biomass of the different vegetation communities and its associated fauna. The GIS application was created by means of the software Arc View 3.3 by Environmental Systems Research Institute, Inc. Distribution readings and quantitative data of submerged macrophyte communities and its associated fauna was obtained from studies by Kautsky et al. and by Borgiel. Information about the macrophyte distribution in Laangoersviken, located in the northern parts of Kallrigafjaerden, was obtained from a report by Upplandsstiftelsen. Information about water depth and bottom substrate was available as USGS DEM file, produced by Geological Survey of Sweden. Complementary data of the covering degree of submerged vegetation was obtained from a study using an under water video camera by Tobiasson. Quantitative data on macrophyte and faunal biomass were either obtained from the primary SKB data base SICADA or directly from reports. Samples were compiled and analysed according to dominating vegetation. The work was carried out as follows: Where information about the bottom substrate was available polygons were created by means of the substrate shape file and depth grid from Geological Survey of Sweden. The vegetation community and the covering degree on a certain depth and substrate combination were determined by compiled information from studies by Kautsky and by Borgiel. All observations from a certain bottom substrate were analysed to find the dominating vegetation within different depth ranges. After determining the dominating vegetation, the covering degrees of different macrophyte classes within each depth range were calculated as a mean of all readings. Areas without information about the bottom substrate, but still adjacent to areas included in the

Submerged macrophyte communities in the Forsmark area. Building of a GIS application as a tool for biomass estimations

Energy Technology Data Exchange (ETDEWEB)

Fredriksson, Ronny [Univ. of Kalmar (Sweden)

2005-12-15

The aim of this study was to compile the information from previous studies to produce a GIS application that both illustrates the distribution of different vegetation communities and also makes it possible to estimate the total biomass of the different vegetation communities and its associated fauna. The GIS application was created by means of the software Arc View 3.3 by Environmental Systems Research Institute, Inc. Distribution readings and quantitative data of submerged macrophyte communities and its associated fauna was obtained from studies by Kautsky et al. and by Borgiel. Information about the macrophyte distribution in Laangoersviken, located in the northern parts of Kallrigafjaerden, was obtained from a report by Upplandsstiftelsen. Information about water depth and bottom substrate was available as USGS DEM file, produced by Geological Survey of Sweden. Complementary data of the covering degree of submerged vegetation was obtained from a study using an under water video camera by Tobiasson. Quantitative data on macrophyte and faunal biomass were either obtained from the primary SKB data base SICADA or directly from reports. Samples were compiled and analysed according to dominating vegetation. The work was carried out as follows: Where information about the bottom substrate was available polygons were created by means of the substrate shape file and depth grid from Geological Survey of Sweden. The vegetation community and the covering degree on a certain depth and substrate combination were determined by compiled information from studies by Kautsky and by Borgiel. All observations from a certain bottom substrate were analysed to find the dominating vegetation within different depth ranges. After determining the dominating vegetation, the covering degrees of different macrophyte classes within each depth range were calculated as a mean of all readings. Areas without information about the bottom substrate, but still adjacent to areas included in the

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 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.

Measuring ecological change of aquatic macrophytes in Mediterranean rivers

OpenAIRE

Dodkins, Ian; Aguiar, Francisca; Rivaes, Rui; Albuquerque, António; Rodriguez-Gonzalez, Patricia; Ferreira, Maria Teresa

2012-01-01

A metric was developed for assessing anthropogenic impacts on aquatic macrophyte ecology by scoring macrophyte species along the main gradient of community change. A measure of ecological quality was then calculated by Weighted Averaging (WA) of these species scores at a monitoring site, and comparison to a reference condition score. This metric was used to illustrate the difficulties of developing aquatic macrophyte indices based on indicator species in Mediterranean rivers. The ...

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

Science.gov (United States)

Yang, Na; Zhang, Yehui; Duan, Kai

2017-01-01

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.

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

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...

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

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.

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

also showed that environmental variables such as depth, transparency/depth ratio, total P, chl-a, and TSM differed significantly between the two lagoons. In order to assess the ecological quality of the study sites, the functional ISD index has been applied. From the preliminary results it seems that ISD index, based on the biomass size structure of the macroinvertebrate communities, is more appropriate for the assessment of the ecological status for these particular ecosystems. The development of a monitoring team is essential for the protection and management of these ecologically important ecosystems. Further investigation is necessary to examine the relationships between benthic macroinvertebrates and aquatic macrophytes, the use of biotic indices to the evaluation for lagoonal ecosystems' ecological status and the relation between the hydrological processes and the biodiversity patterns of the biotic elements.

Macrophyte community development and its implication for fisheries ...

African Journals Online (AJOL)

Agricultural activities, and poor management practices over the years have led to high siltation rates and consequent extensive growth of emergent aquatic macrophytes such as Typha australis, Nymphaea lotus, Echinochloa pyramidalis and Leersia hexandra, as well as marginal plants such as Mimosa pigra and Sesbania ...

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.

Effects of submerged macrophytes on the abundance and community composition of ammonia-oxidizing prokaryotes in a eutrophic lake.

Science.gov (United States)

Zhao, Da-yong; Luo, Juan; Zeng, Jin; Wang, Meng; Yan, Wen-ming; Huang, Rui; Wu, Qinglong L

2014-01-01

Abundances and community compositions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in unvegetated sediment and the rhizosphere sediments of three submerged macrophytes (Ceratophyllum demersum, Vallisneria spinulosa, and Potamogeton crispus) were investigated in a large, eutrophic freshwater lake, Lake Taihu. Abundances of archaeal ammonia monooxygenase alpha-subunit (amoA) gene (from 6.56 × 10(6) copies to 1.06 × 10(7) copies per gram of dry sediment) were higher than those of bacterial amoA (from 6.13 × 10(5) to 3.21 × 10(6) copies per gram of dry sediment) in all samples. Submerged macrophytes exhibited no significant effect on the abundance and diversity of archaeal amoA gene. C. demersum and V. spinulosa increased the abundance and diversity of bacterial amoA gene in their rhizosphere sediment. However, the diversity of bacterial amoA gene in the rhizosphere sediments of P. crispus was decreased. The data obtained in this study would be helpful to elucidate the roles of submerged macrophytes involved in the nitrogen cycling of eutrophic lake ecosystems.

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

Directory of Open Access Journals (Sweden)

Amany M. Haroon

2017-09-01

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

Environmental clustering of lakes to evaluate performance of a macrophyte index of biotic integrity

Science.gov (United States)

Vondracek, Bruce C.; Vondracek, Bruce; Hatch, Lorin K.

2013-01-01

Proper classification of sites is critical for the use of biological indices that can distinguish between natural and human-induced variation in biological response. The macrophyte-based index of biotic integrity was developed to assess the condition of Minnesota lakes in relation to anthropogenic stressors, but macrophyte community composition varies naturally across the state. The goal of the study was to identify environmental characteristics that naturally influence macrophyte index response and establish a preliminary lake classification scheme for biological assessment (bioassessment). Using a comprehensive set of environmental variables, we identified similar groups of lakes by clustering using flexible beta classification. Variance partitioning analysis of IBI response indicated that evaluating similar lake clusters could improve the ability of the macrophyte index to identify community change to anthropogenic stressors, although lake groups did not fully account for the natural variation in macrophyte composition. Diagnostic capabilities of the index could be improved when evaluating lakes with similar environmental characteristics, suggesting the index has potential for accurate bioassessment provided comparable groups of lakes are evaluated.

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.

Comparing macrophyte herbivory by introduced Louisiana crayfish ...

African Journals Online (AJOL)

The omnivorous Louisiana crayfish, Procambarus clarkii, has caused significant changes to macrophyte communities worldwide and may have similar negative effects in Kenya if used as a biological control agent for snails harbouring human schistosomes. Here we examine how herbivory by the introduced Louisiana ...

Responses of aquatic macrophytes to anthropogenic pressures: comparison between macrophyte metrics and indices.

Science.gov (United States)

Camargo, Julio A

2018-02-26

Macrophyte responses to anthropogenic pressures in two rivers of Central Spain were assessed to check if simple metrics can exhibit a greater discriminatory and explanatory power than complex indices at small spatial scales. Field surveys were undertaken during the summer of 2014 (Duraton River) and the spring of 2015 (Tajuña River). Aquatic macrophytes were sampled using a sampling square (45 × 45 cm). In the middle Duraton River, macrophytes responded positively to the presence of a hydropower dam and a small weir, with Myriophyllum spicatum and Potamogeton pectinatus being relatively favored. Index of Macrophytes (IM) was better than Macroscopic Aquatic Vegetation Index (MAVI) and Fluvial Macrophyte Index (FMI) in detecting these responses, showing positive and significant correlations with total coverage, species richness, and species diversity. In the upper Tajuña River, macrophytes responded both negatively and positively to the occurrence of a trout farm effluent and a small weir, with Leptodictyum riparium and Veronica anagallis-aquatica being relatively favored. Although IM, MAVI, and FMI detected both negative and positive responses, correlations of IM with total coverage, species richness, and species diversity were higher. Species evenness was not sensitive enough to detect either positive or negative responses of aquatic macrophytes along the study areas. Overall, traditional and simple metrics (species composition, total coverage, species richness, species diversity) exhibited a greater discriminatory and explanatory power than more recent and complex indices (IM, MAVI, FMI) when assessing responses of aquatic macrophytes to anthropogenic pressures at impacted specific sites.

Optimum water depth ranges of dominant submersed macrophytes in a natural freshwater lake.

Science.gov (United States)

Ye, Bibi; Chu, Zhaosheng; Wu, Aiping; Hou, Zeying; Wang, Shengrui

2018-01-01

Macrophytes show a zonal distribution along the lake littoral zone because of their specific preferred water depths while the optimum growth water depths of dominant submersed macrophytes in natural lakes are not well known. We studied the seasonal biomass and frequency patterns of dominant and companion submersed macrophytes along the water depth gradient in Lake Erhai in 2013. The results showed that the species richness and community biomass showed hump-back shaped patterns along the water depth gradient both in polydominant and monodominant communities. Biomass percentage of Potamogenton maackianus showed a hump-back pattern while biomass percentages of Ceratophyllum demersum and Vallisneria natans appeared U-shaped patterns across the water depth gradient in polydominant communities whereas biomass percentage of V. natans increased with the water depth in monodominant communities. Dominant species demonstrated a broader distribution range of water depth than companion species. Frequency and biomass of companion species declined drastically with the water depth whereas those of dominant species showed non-linear patterns across the water depth gradient. Namely, along the water depth gradient, biomass of P. maackianus and V. natans showed hump-back patterns and biomasses of C. demersum displayed a U-shaped pattern in the polydominant communities but biomass of V. natans demonstrated a hump-back pattern in the monodominant communities; frequency of P. maackianus showed a hump-back pattern and C. demersum and V. natans maintained high frequencies in the two types of communities. We can speculate that in Lake Erhai the optimum growth water depths of P. maackianus and C. demersum in the polydominant communities are 2.5-4.5 m and 1-2 m or 5-6 m, respectively and that of V. natans is 3-5 m in the polydominant communities and 2.5-5 m in the monodominant communities. This is the first report that the optimum water depth ranges in the horizontal direction of three

Development of a macrophyte-based index of biotic integrity for Minnesota lakes

Science.gov (United States)

Beck, M.W.; Hatch, L.K.; Vondracek, B.; Valley, R.D.

2010-01-01

Traditional approaches for managing aquatic resources have often failed to account for effects of anthropogenic disturbances on biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective assessment method to integrate ecological, functional, and structural aspects of aquatic systems. A macrophyte-based IBI was developed for Minnesota lakes to assess the ability of aquatic plant communities to indicate environmental condition. The index was developed using quantitative point intercept vegetation surveys for 97 lakes that represent a range of limnological and watershed characteristics. We followed an approach similar to that used in Wisconsin to develop the aquatic macrophyte community index (AMCI). Regional adaptation of the AMCI required the identification of species representative of macrophyte communities in Minnesota. Metrics and scaling methods were also substantially modified to produce a more empirically robust index. Regression analyses indicated that IBI scores reflected statewide differences in lake trophic state (R2 = 0.57, F = 130.3, df = 1, 95, p indicated a unique response of the IBI to human-induced stress separate from a response to natural lake characteristics. The IBI was minimally affected by differences in sample point density as indicated by Monte Carlo analyses of reduced sampling effort. Our analysis indicates that a macrophyte IBI calibrated for Minnesota lakes could be useful for identifying differences in environmental condition attributed to human-induced stress gradients. ?? 2010 Elsevier Ltd.

Response of littoral macrophytes to water level fluctuations in a storage reservoir

Directory of Open Access Journals (Sweden)

Krolová M.

2013-05-01

Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

Fluoride remediation using floating macrophytes

Directory of Open Access Journals (Sweden)

Naba Kumar Mondal

2014-04-01

Full Text Available Six aquatic macrophytes, such as Pistia stratiotes, Ceratophyllum demersum, Nymphoides indica, Lemna major, Azolla pinnata,and Eichhornia crassipes were considered for remove fluoride from aqueous solution. Five different concentrations (10, 30, 50, and 100 ppm of fluoride solution were taken in 1 L plastic container. Fixed weight (20 g of macrophytes along with 500 ml fluoride solution was taken in each plastic container for 72 hours observation. Results demonstrated all the macrophytes show highest fluoride removal during 24 h to 48 h, but after 72 h their efficiency reduced drastically. The species N. indica showed better removal efficiency than other experimental macrophytes. In general, pigment measurement data indicated higher concentration at 72 h. However, Pistia sp. showed higher concentration of pigmentation at intermediate time interval (48 h. Higher level of dry weight to fresh weight ratio was recorded for L. major and A. pinnata at all concentrations, excepting at 10 ppm. In addition, all macrophytes showed lower RGR at higher concentration. Isotherm study indicated that macrophyte C. demersum is a good fitted with Freundlich and Langmuir isotherm whereas L. major with Langmuir isotherm during 24 hours.

Genetic and nutritional characterization of some macrophytes, inhabiting the Bardawil Lagoon, Sinai, Egypt

Directory of Open Access Journals (Sweden)

Hosam E. Elsaied

2015-12-01

Full Text Available The ecological and economical significances of macrophytes, inhabiting the Mediterranean Lagoon, Bardawil, northern Sinai, Egypt, are still ambiguous, due to lack of knowledge. This study focused on genetic and nutritional characterization of three dominant macrophyte species at Bardawil Lagoon. Genetic identifications were done through genomic DNA extraction, followed by PCR amplifications and sequencing of 18S rRNA genes of the studied species. Phylogenetic analyses indicated that two of the recorded species showed homologies with the seagrass species, Posidonia oceanica and Halophila ovalis, with nucleotide identities 94.5% and 96.8%, respectively. The third species showed a unique phylogenetic lineage, representing nucleotide identity average, 86.5%, among the brown seaweeds, Heterokontophyta. Nutritional analyses indicated that the recorded seaweed-like macrophyte had the highest recommended nutritional contents, crude protein, 24.67%, with a total amino acid composition of 6.64 g/100 g protein, and carbohydrate, 38.16%, besides a calorific value of 3.063 K cal/g, among the studied macrophytes. To the best of our knowledge, this is the first attempt to characterize macrophyte community in Bardawil Lagoon, using both genetic and biochemical approaches.

Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

Energy Technology Data Exchange (ETDEWEB)

Ibanez, Carles, E-mail: carles.ibanez@irta.cat [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alonso, Miguel [United Research Services S.L., Urgell 143, 08036 Barcelona, Catalonia (Spain); Duran, Concha [Confederacion Hidrografica del Ebro, Sagasta 24-26, 50071 Zaragoza, Aragon (Spain); Jimenez, Pere J. [Grup Natura Freixe, Major 56, 43750 Flix, Catalonia (Spain); Munne, Antoni [Agencia Catalana de l' Aigua, Provenca 204-208, 08036 Barcelona, Catalonia (Spain); Prat, Narcis [Departament d' Ecologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona Catalonia (Spain)

2012-02-01

The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: Black-Right-Pointing-Pointer We show a regime shift in a large river from phytoplankton to macrophyte dominance. Black-Right-Pointing-Pointer Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. Black-Right-Pointing-Pointer Phosphorus depletion is found to be the main cause of the phytoplankton decline. Black-Right-Pointing-Pointer We conclude that oligotrophication triggered the colonization of macrophytes. Black-Right-Pointing-Pointer This new regime shift in a river is similar to that described

Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

International Nuclear Information System (INIS)

Ibáñez, Carles; Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa; Alonso, Miguel; Duran, Concha; Jiménez, Pere J.; Munné, Antoni; Prat, Narcís

2012-01-01

The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: ► We show a regime shift in a large river from phytoplankton to macrophyte dominance. ► Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. ► Phosphorus depletion is found to be the main cause of the phytoplankton decline. ► We conclude that oligotrophication triggered the colonization of macrophytes. ► This new regime shift in a river is similar to that described in shallow lakes.

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.

Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

International Nuclear Information System (INIS)

Taggart, M.A.; Mateo, R.; Charnock, J.M.; Bahrami, F.; Green, A.J.; Meharg, A.A.

2009-01-01

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 -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

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

OpenAIRE

Ana Silvia Rolon; Henrique Flores Homem; Leonardo Maltchik

2010-01-01

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; ...

Effects of taxonomy, sediment, and water column on C:N:P stoichiometry of submerged macrophytes in Yangtze floodplain shallow lakes, China.

Science.gov (United States)

Su, Haojie; Wu, Yao; Xie, Ping; Chen, Jun; Cao, Te; Xia, Wulai

2016-11-01

Carbon (C), nitrogen (N) and phosphorus (P) are the three most important essential elements limiting growth of primary producers. Submerged macrophytes generally absorb nutrients from sediments by root uptake. However, the C:N:P stoichiometric signatures of plant tissue are affected by many additional factors such as taxonomy, nutrient availability, and light availability. We first revealed the relative importance of taxonomy, sediment, and water column on plant C:N:P stoichiometry using variance partitioning based on partial redundancy analyses. Results showed that taxonomy was the most important factor in determining C:N:P stoichiometry, then the water column and finally the sediment. In this study, a significant positive relationship was found between community C concentration and macrophyte community biomass, indicating that the local low C availability in macrophytes probably was the main reason why submerged macrophytes declined in Yangtze floodplain shallow lakes. Based on our study, it is suggested that submerged macrophytes in Yangtze floodplain shallow lakes are primarily limited by low light levels rather than nutrient availability.

Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages

OpenAIRE

Rolon, A. S.; Godoy, R. S.; Maltchik, L.

2017-01-01

Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of n...

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.

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.

Shear Stress and Sediment Resuspension in Canopy-and Meadow-Forming Submersed Macrophyte Communities

National Research Council Canada - National Science Library

James, William

2001-01-01

.... Studies were conducted at Lake Christina, Minnesota, in late August-early September 1998, when macrophyte biomass levels exceeded 200 g/m2 and in June 2000, when biomass was greatly reduced (<20 g/m2...

The Future of Freshwater Macrophytes in a Changing World: Dissolved Organic Carbon Quantity and Quality and Its Interactions With Macrophytes

Directory of Open Access Journals (Sweden)

Rosanne E. Reitsema

2018-05-01

Full Text Available Freshwater ecosystems are confronted with the effects of climate change. One of the major changes is an increased concentration of aquatic carbon. Macrophytes are important in the aquatic carbon cycle and play as primary producers a crucial role in carbon storage in aquatic systems. However, macrophytes are affected by increasing carbon concentrations. The focus of this review lies on dissolved organic carbon (DOC, one of the most abundant forms of carbon in aquatic ecosystems which has many effects on macrophytes. DOC concentrations are rising; the exact cause of this increase is not known, although it is hypothesized that climate change is one of the drivers. The quality of DOC is also changing; for example, in urban areas DOC composition is different from the composition in natural watersheds, resulting in DOC that is more resistant to photo-degradation. Plants can benefit from DOC as it attenuates UV-B radiation, it binds potentially harmful heavy metals and provides CO2 as it breaks down. Yet plant growth can also be impaired under high DOC concentrations, especially by humic substances (HS. HS turn the water brown and attenuate light, which limits macrophyte photosynthesis at greater depths. This leads to lower macrophyte abundance and lower species diversity. HS form a wide class of chemicals with many different functional groups and they therefore have the ability to interfere with many biochemical processes that occur in freshwater organisms. Few studies have looked into the direct effects of HS on macrophytes, but there is evidence that HS can interfere with photosynthesis by entering macrophyte cells and causing damage. DOC can also affect reactivity of heavy metals, water and sediment chemistry. This indirectly affects macrophytes too, so they are exposed to multiple stressors that may have contradictive effects. Finally, macrophytes can affect DOC quality and quantity as they produce DOC themselves and provide a substrate to

Factors Affecting the Distribution of Wild Rice (Zizania palustris) and the Surrounding Macrophyte Community.

Science.gov (United States)

Pillsbury, R. W.; McGuire, M.

2005-05-01

A recent decline in wild rice wetlands is cause for concern due to its importance as a food source, refuge for wildlife, and cultural significance. Sixty wetlands in Wisconsin and Minnesota (USA) were sampled, with approximately equal numbers displaying dense, moderate and sparse wild rice production. Chemical, physical, and watershed parameters were measured as well as macrophyte densities. Data were analyzed using multivariate statistics (CCA). Moderate levels of phosphorus appear beneficial to the overall success of wild rice, while free-floating macrophytes show an overwhelming positive response to higher levels of P. The distribution of macrophytes bordering wild rice beds is correlated to pH,with Potamogeton robbinsii and filamentous green algae responding most strongly to its increase. Healthy stands of wild rice exhibit a narrow circum-neutral range of pH (6.1-8.0)which is significantly different from the greater range exhibited by sparse wild rice wetlands (6.5-8.5). This pattern was paralleled when considering depth which suggests that deeper wetlands may be more susceptible to wild rice loss. Management of existing wild rice wetlands should focus monitoring on pH, depth, phosphorus concentrations and shore development. We are currently using this data base to locate the best reintroduction sites for wild rice.

Functional Traits for Carbon Access in Macrophytes.

Science.gov (United States)

Stepien, Courtney C; Pfister, Catherine A; Wootton, J Timothy

2016-01-01

Understanding functional trait distributions among organisms can inform impacts on and responses to environmental change. In marine systems, only 1% of dissolved inorganic carbon in seawater exists as CO2. Thus the majority of marine macrophytes not only passively access CO2 for photosynthesis, but also actively transport CO2 and the more common bicarbonate (HCO3-, 92% of seawater dissolved inorganic carbon) into their cells. Because species with these carbon concentrating mechanisms (CCMs) are non-randomly distributed in ecosystems, we ask whether there is a phylogenetic pattern to the distribution of CCMs among algal species. To determine macrophyte traits that influence carbon uptake, we assessed 40 common macrophyte species from the rocky intertidal community of the Northeast Pacific Ocean to a) query whether macrophytes have a CCM and b) determine the evolutionary history of CCMs, using ancestral state reconstructions and stochastic character mapping based on previously published data. Thirty-two species not only depleted CO2, but also concentrated and depleted HCO3-, indicative of a CCM. While analysis of CCMs as a continuous trait in 30 families within Phylum Rhodophyta showed a significant phylogenetic signal under a Brownian motion model, analysis of CCMs as a discrete trait (presence or absence) indicated that red algal families are more divergent than expected in their CCM presence or absence; CCMs are a labile trait within the Rhodophyta. In contrast, CCMs were present in each of 18 Ochrophyta families surveyed, indicating that CCMs are highly conserved in the brown algae. The trait of CCM presence or absence was largely conserved within Families. Fifteen of 23 species tested also changed the seawater buffering capacity, or Total Alkalinity (TA), shifting DIC composition towards increasing concentrations of HCO3- and CO2 for photosynthesis. Manipulating the external TA of the local environment may influence carbon availability in boundary layers and

Functional Traits for Carbon Access in Macrophytes

Science.gov (United States)

Pfister, Catherine A.; Wootton, J. Timothy

2016-01-01

Understanding functional trait distributions among organisms can inform impacts on and responses to environmental change. In marine systems, only 1% of dissolved inorganic carbon in seawater exists as CO2. Thus the majority of marine macrophytes not only passively access CO2 for photosynthesis, but also actively transport CO2 and the more common bicarbonate (HCO3-, 92% of seawater dissolved inorganic carbon) into their cells. Because species with these carbon concentrating mechanisms (CCMs) are non-randomly distributed in ecosystems, we ask whether there is a phylogenetic pattern to the distribution of CCMs among algal species. To determine macrophyte traits that influence carbon uptake, we assessed 40 common macrophyte species from the rocky intertidal community of the Northeast Pacific Ocean to a) query whether macrophytes have a CCM and b) determine the evolutionary history of CCMs, using ancestral state reconstructions and stochastic character mapping based on previously published data. Thirty-two species not only depleted CO2, but also concentrated and depleted HCO3-, indicative of a CCM. While analysis of CCMs as a continuous trait in 30 families within Phylum Rhodophyta showed a significant phylogenetic signal under a Brownian motion model, analysis of CCMs as a discrete trait (presence or absence) indicated that red algal families are more divergent than expected in their CCM presence or absence; CCMs are a labile trait within the Rhodophyta. In contrast, CCMs were present in each of 18 Ochrophyta families surveyed, indicating that CCMs are highly conserved in the brown algae. The trait of CCM presence or absence was largely conserved within Families. Fifteen of 23 species tested also changed the seawater buffering capacity, or Total Alkalinity (TA), shifting DIC composition towards increasing concentrations of HCO3- and CO2 for photosynthesis. Manipulating the external TA of the local environment may influence carbon availability in boundary layers and

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

Science.gov (United States)

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

2010-05-01

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). 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.

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.

Primary productivity of marine macrophytes in the coral reef lagoon of the Kadmat Island, Lakshadweep

Digital Repository Service at National Institute of Oceanography (India)

Dhargalkar, V.K.; Shaikh, N.

n situ primary productivity measurements were carried out with different macrophyte species (belonging to four groups) dominating the benthic communities in the coral reef lagoon of the Kadmat Island of the Lakshadweep Archipelago...

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.

Sensitivity of submersed freshwater macrophytes and endpoints in laboratory toxicity tests

International Nuclear Information System (INIS)

Arts, Gertie H.P.; Belgers, J. Dick M.; Hoekzema, Conny H.; Thissen, Jac T.N.M.

2008-01-01

The toxicological sensitivity and variability of a range of macrophyte endpoints were statistically tested with data from chronic, non-axenic, macrophyte toxicity tests. Five submersed freshwater macrophytes, four pesticides/biocides and 13 endpoints were included in the statistical analyses. Root endpoints, reflecting root growth, were most sensitive in the toxicity tests, while endpoints relating to biomass, growth and shoot length were less sensitive. The endpoints with the lowest coefficients of variation were not necessarily the endpoints, which were toxicologically most sensitive. Differences in sensitivity were in the range of 10-1000 for different macrophyte-specific endpoints. No macrophyte species was consistently the most sensitive. Criteria to select endpoints in macrophyte toxicity tests should include toxicological sensitivity, variance and ecological relevance. Hence, macrophyte toxicity tests should comprise an array of endpoints, including very sensitive endpoints like those relating to root growth. - A range of endpoints is more representative of macrophyte fitness than biomass and growth only

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

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

Science.gov (United States)

van der Wal, Jessica E M; Dorenbosch, Martijn; Immers, Anne K; Vidal Forteza, Constanza; Geurts, Jeroen J M; Peeters, Edwin T H M; Koese, Bram; Bakker, Elisabeth 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 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.

Evaluation of invasions and declines of submersed aquatic macrophytes

Science.gov (United States)

Chambers, P.A.; Barko, J.W.; Smith, C.S.

1993-01-01

During the past 60 yr, sightings of aquatic macrophyte species in geographic regions where they had previously not been found have occurred with increasing frequency, apparently due to both greater dispersal of the plants as a result of human activities as well as better documentation of plant distribution. Intercontinental invasions, such as Myriophyllum spicatum and Hydrilla into North America, Elodea canadensis into Europe and Elodea nuttallii, Egeria densa and Cabomba caroliniana into Japan, have generally been well documented. However, the spread of an exotic species across a continent after its initial introduction (e.g., Potamogeton crispus in North America) or the expansion of a species native to a continent into hitherto unexploited territory (e.g.,the expansion of the North American native Myriophyllum heterophyllum into New England) have received little attention. Natural declines in aquatic macrophyte communities have also received little scientific study although there are many accounts of macrophyte declines. The best-documented example comes from the marine literature where extensive declines of eelgrass (Zostera) occurred in the 1930s along the Atlantic coast due to a pathogenic marine slime mold (''wasting disease''). The aim of this workshop was to identify examples of invasions or natural declines of aquatic macrophyte species throughout the world and assess the importance of environmental factors in their control. Forty-five scientists and aquatic plant managers from ten countries participated in the workshop. Eleven of the participants contributed written evaluations of species invasions and declines in their geo-graphic region. These were distributed to registered participants prior to the meeting and served as the starting-point of workshop discussions. To address the topics raised in the working papers, the participants divided into four working groups to evaluate: 1. Environmental controls of species invasions. 2. Biotic controls of species

Macrophyte assemblage composition as a simple tool to assess global change in coastal areas. Freshwater impacts and climatic changes.

Science.gov (United States)

Buosi, Alessandro; Sfriso, Adriano

2017-12-15

Macrophyte assemblages are one of the most sensitive biological communities to assess anthropogenic impacts and climate changes. Community composition responds very quickly to environmental changes driving towards a predictable composition. The increase or decrease of the trophic status (i.e. nutrient concentrations, suspended particulate matter, Chlorophyll-a) and temperature are the most important factors responsible for the replacement of taxa of high ecological value (sensitive taxa) with opportunistic species. A qualitative and quantitative study of macrophytes in 4 areas along the coasts of the Northern Adriatic Sea, from Venice (Italy) to Savudrija (Croatia) and the analysis of river outflows in this region during one year (May 2012-April 2013) provided information about their spatial variability. The coasts of the Veneto Region and Friuli-Venezia Giulia, which are affected by significant freshwater inputs, showed a strong biodiversity reduction or a dominance of thionitrophilic taxa. No seagrasses colonized these areas. On the other hand, the coasts of Croatia had negligible fresh water inputs and macrophyte communities were dominated by sensitive taxa such as the seagrass Cymodocea nodosa and some species belonging to genus Cystoseira. Copyright © 2017 Elsevier B.V. All rights reserved.

[Algal control ability of allelopathically active submerged macrophytes: a review].

Science.gov (United States)

Xiao, Xi; Lou, Li-ping; Li, Hua; Chen, Ying-xu

2009-03-01

The inhibitory effect of allelochemicals released by submerged macrophytes on phytoplankton is considered as one of the mechanisms that contribute to the stabilization of clear-water status in shallow lakes. This paper reviewed the research progress in the allelopathy of submerged macrophytes on algae from the aspects of the occurrence frequency and coverage of allelopathically active submerged macrophytes in lakes, and the kinds and allelopathical effects of the allelochemicals released from the macrophytes. The previous researches indicated that allelopathically active submerged macrophyte species such as Myriophyllum, Ceratophyllum, and Elodea were efficient to control phytoplankton, especially when their biomass was high enough, and the dominant algae were sensitive species. The allelochemicals such as hydroxybenzene released by the submerged macrophytes could inhibit the growth of algae. Different phytoplankton species exhibited different sensitivity against allelochemicals, e.g., cyanobacteria and diatom were more sensitive than green algae, while epiphytic species were less sensitive than phytoplankton. Environmental factors such as light, temperature, and nutrients could significantly affect the allelopathical effect of submerged macrophytes. The research of the allelopathy of submerged macrophytes is still at its beginning, and further researches are needed on the effects of environmental factors on the allelopathy, extraction and identification of allelochemicals, selective algal control mechanisms, and metabolism of the allelochmicals.

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

Science.gov (United States)

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

2015-05-13

Stoichiometric homeostasis of element composition is one of the central concepts of ecological stoichiometry. We analyzed concentrations of macroelements (C, N, P, Ca, K, Mg, S), microelements (Cu, Fe, Mn, Mo, Ni, Zn) and beneficial elements (Na, Se, Si) in submerged macrophytes, water and sediments across 20 Yunnan plateau lakes. 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. Canonical discriminant analyses successfully discriminated among trophic level groups and taxa groups. Of all the elements, C, N, P and S most effectively discriminated among trophic level groups across 20 lakes, revealing lake trophic level mostly affect tissue macroelement composition in submerged macrophytes; while Ca, K and Se most effectively discriminated among submerged macrophytes taxa groups, suggesting taxonomy mostly affect compositions of macroelements and beneficial elements in submerged macrophytes. In addition, the stoichiometric homeostatic coefficient of 1/HCa:C for all five taxa of submerged macrophytes were less than zero, suggesting submerged macrophytes in Yunnan plateau lakes have strong Ca stoichiometric homeostasis. Our findings, not only broaden the knowledge of multielement stoichiometric homeostasis, but also help to choose most appropriate lake management strategy.

Macrophytes: Freshwater Forests of Lakes and Rivers.

Science.gov (United States)

McDermid, Karla J.; Naiman, Robert J.

1983-01-01

Physical, chemical, and biological effects on macrophytes (aquatic plants) on the freshwater ecosystem are discussed. Research questions and issues related to these organisms are also discussed, including adaptations for survival in a wet environment, ecological consequences of large-scale macrophyte eradication, seasonal changes in plant…

Modeling Refuge Effect of Submerged Macrophytes in Lake System.

Science.gov (United States)

Lv, Dongyu; Fan, Meng; Kang, Yun; Blanco, Krystal

2016-04-01

This paper considers a significant problem in biological control of algae issue in ecological environment. A four-dimensional dynamic model is carefully formulated to characterize the interactions among phytoplankton, submerged macrophyte, zooplankton, and general fish class in a lake ecosystem. The predation relationship is modeled by Beddington-DeAngelis functional responses derived from the classical Holling time budget arguments. Qualitative analyses of the global dynamics show that the system can generate very rich dynamics with potentially 10 different equilibria and several bistable scenarios. We perform analysis on the existence and local stability of equilibria and explore the refuge effect of macrophyte on the zooplankton with numerical simulations on aquatic ecosystems. We also discuss effective methods of biological control used to restrain the increase of phytoplankton. Our study shows the proposed model could have rich and complex dynamics including but not limited to bistable and chaotic phenomenon. Numerical simulation results demonstrate that both the refuge constant and the density of the macrophytes are two key factors where refuge effects take place. In addition, the intraspecific competition between the macrophyte and the phytoplankton can also affect the macrophyte's refuge effect. Our analytical and simulation results suggest that macrophytes provide structure and shelter against predation for zooplankton such that it could restore the zooplankton population, and that planting macrophyte properly might achieve the purpose of controlling algae growth.

The decomposition of estuarine macrophytes under different ...

African Journals Online (AJOL)

The aim of this study was to determine the decomposition characteristics of the most dominant submerged macrophyte and macroalgal species in the Great Brak Estuary. Laboratory experiments were conducted to determine the effect of different temperature regimes on the rate of decomposition of 3 macrophyte species ...

Management of fresh water weeds (macrophytes) by vermicomposting using Eisenia fetida.

Science.gov (United States)

Najar, Ishtiyaq Ahmed; Khan, Anisa B

2013-09-01

In the present study, potential of Eisenia fetida to recycle the different types of fresh water weeds (macrophytes) used as substrate in different reactors (Azolla pinnata reactor, Trapa natans reactor, Ceratophyllum demersum reactor, free-floating macrophytes mixture reactor, and submerged macrophytes mixture reactor) during 2 months experiment is investigated. E. fetida showed significant variation in number and weight among the reactors and during the different fortnights (P macrophytes mixture reactor (number 105 ± 5.77 %; weight 41.07 ± 3.97 % ). ANOVA showed significant variation in cocoon production (F4 = 15.67, P macrophyte affects the growth and reproduction pattern of E. fetida among the different reactors, further the addition of A. pinnata in other macrophytes reactors can improve their recycling by E. fetida.

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...

Macrophytes shape trophic niche variation among generalist fishes.

Directory of Open Access Journals (Sweden)

Ivana Vejříková

Full Text Available Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N and carbon (δ13C isotopic mixing models, perch (Perca fluviatilis L. and rudd (Scardinius erythrophthalmus (L. showed larger individual variation (i.e., variance in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.. Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence

Macrophytes shape trophic niche variation among generalist fishes

Science.gov (United States)

Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, Mikko; Peterka, Jiří

2017-01-01

Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall

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.

Multispectral televisional measuring control of the ecological state of waterbodies on the characteristics macrophytes

Science.gov (United States)

Petruk, Vasil; Kvaternyuk, Sergii; Kozachuk, Anastasia; Sailarbek, Saltanat; Gromaszek, Konrad

2015-12-01

Improved methods for multispectral measuring television monitoring of the ecological state of water bodies on the characteristics of macrophytes groups to assess complex human impact on their environment. Integral assessment of water pollution is based on research products of higher aquatic plants and their communities by optical methods.

Arsenic rich iron plaque on macrophyte roots--an ecotoxicological risk?

Science.gov (United States)

Taggart, M A; Mateo, R; Charnock, J M; Bahrami, F; Green, A J; Meharg, A A

2009-03-01

Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcóllar 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(-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 Aznalcóllar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque.

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.

Influence of unreasoned economic activity on the condition of macrophytes of the Bol’shoye Goluboye Lake

Science.gov (United States)

Palagushkina, O. V.; Zaripova, N. R.; Mingazova, N. M.; Yarutkin, T. O.

2018-01-01

The ecosystem of Lake Bolshoye Goluboe had undergone a strong anthropogenic impact in 2013 as a result of the implementation of the dam reconstruction project. Studies in 2014 have shown that the implementation of the project for the reconstruction of the Bolshoye Goluboe dam has negatively affected on the species richness of macrophytes. The total species composition of the lake and species richness of the water core decreased twofold, Hippuris vulgaris L., Zannichellia palustris L, Ceratophyllum demersum L., and the species listed in the Red Book of the Republic of Tatarstan - Batrachium circinatum (Sibth.) Spach disappeared from the species composition. The area occupied by macrophyte communities has decreased by 55%.

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 ...

AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

OpenAIRE

Arts, G.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.; Hommen, U.; Knauer, K.; Loutseti, S.; Maltby, L.; Mohr, S.; Poovey, A.; Poulsen, V.

2010-01-01

\\ud Introduction and background\\ud \\ud 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 be...

AMEG: the new SETAC advisory group on auqatic macrophyte ecotoxicology

OpenAIRE

Arts, G.H.P.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.A.

2010-01-01

ntroduction 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 dif...

[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.

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

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

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...

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.

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

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...... dortmanna have been shown to release oxygen from their roots and to stimulate nitrification and coupled nitrification-denitrification in the rhizosphere. Together with the excretion of root exudates, this effect leads to strongly modified microenvironments at the root surface and in the rhizosphere compared......-denitrification using the 15N isotope pairing technique. Ammonia-oxidizing and nitrate-reducing populations are analyzed based on the ammonia monooxygenase gene (amoA) and the nitrate reductase gene (narG) as functional markers. Preliminary data indicate that there in fact exist differences in the community composition...

Factors affecting palatability of four submerged macrophytes for grass carp Ctenopharyngodon idella.

Science.gov (United States)

Sun, Jian; Wang, Long; Ma, Lin; Min, Fenli; Huang, Tao; Zhang, Yi; Wu, Zhenbin; He, Feng

2017-12-01

Grass carp can weaken the growth and reproductive capacity of submerged macrophytes by consuming valuable tissues, but factors affecting palatability of submerged macrophytes for grass carp rarely are considered. In this study, relative consumption rate of grass carp with regard to submerged macrophytes was in the following order: Hydrilla verticillata > Vallisneria natans > Ceratophyllum demersum > Myriophyllum spicatum. Firmness of macrophytes was in the following order: M. spicatum > C. demersum > H. verticillata = V. natans, whereas shear force was M. spicatum > C. demersum > H. verticillata > V. natans. After crude extracts of M. spicatum were combined with H. verticillata, grass carp fed on fewer macrophyte pellets that contained more plant secondary metabolites (PSMs). This indicated that structure and PSMs affected palatability of macrophytes.PSMs do not contribute to reduction in palatability through inhibition of intestinal proteinases activity, but they can cause a decrease in the abundance of Exiguobacterium, Acinetobacter-yielding proteases, lipases, and cellulose activity, which in turn can weaken the metabolic capacity of grass carp and adversely affect their growth. Thus, the disadvantages to the growth and development of grass carp caused by PSMs may drive grass carp to feed on palatable submerged macrophytes with lower PSMs.

Performance assessment of aquatic macrophytes for treatment of municipal wastewater.

Science.gov (United States)

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 species i.e. water hyacinth, duckweed & water lettuce were selected to use. To evaluate the treatment performance of each macrophyte, BOD5, COD, and Nutrients (Nitrogen and Phosphorus) were monitored in effluent from model at different detention time of every experimental run after ensuring steady state conditions. The average reduction of effluent value of each parameter using water hyacinth were 50.61% for BOD5, 46.38% for COD, 40.34% for Nitrogen and 18.76% for Phosphorus. For duckweed the average removal efficiency for selected parameters were 33.43% for BOD5, 26.37% for COD, 17.59% for Nitrogen and 15.25% for Phosphorus and for Water Lettuce the average removal efficiency were 33.43% for BOD5, 26.37% for COD, 17.59% for Nitrogen and 15.25% for Phosphorus. The mechanisms of pollutant removal in this system include both aerobic and anaerobic microbiological conversions, sorption, sedimentation, volatilization and chemical transformations. The rapid growth of the biomass was measured within first ten days detention time. It was also observed that performance of macrophytes is influenced by variation of pH and Temperature. A pH of 6-9 and Temperature of 15-38°C is most favorable for treatment of wastewater by macrophytes. The option of macrophytes for treatment of Municipal sewage under local environmental conditions can be explored by further verifying the removal efficiency under variation of different environmental conditions. Also this is need of time that macrophyte

Effect of removal of free-floating macrophytes on zooplankton habitat in shallow wetland

OpenAIRE

Choi Jong-Yun; Jeong Kwang-Seuk; La Geung-Hwan; Joo Gea-Jae

2014-01-01

Submerged macrophytes improve the structural heterogeneity of microhabitats in aquatic ecosystems, often providing an important habitat for zooplankton. However, excessive development of free-floating macrophytes on the water surface can reduce the biomass of submerged macrophytes and result in a relatively simple habitat structure. We hypothesized that controlling the development of free-floating macrophytes would result in a more complex habitat structure by promoting the development of sub...

TOXICITY OF INDUSTRIAL EFFLUENT ON TOTAL CHLOROPHYLL CONTENT OF CERTAIN AQUATIC MACROPHYTES

OpenAIRE

Singh Priti; Vishen Ashish; Wadhwani R; Pandey Y.N

2012-01-01

To assess the toxicity of industrial effluents on certain macrophytes, the total chlorophyll content of free floating, submerged and emergent macrophytes were estimated in concentrations of industrial effluents at varying exposure duration. The result revealed reduction in total chlorophyll content of exposed macrophytes at higher concentrations of industrial effluents on prolonged duration.

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 ...

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...

Spatiotemporal dynamics of submerged macrophytes in a Mediterranean coastal lagoon

Science.gov (United States)

Obrador, Biel; Pretus, Joan Lluís

2010-03-01

The seasonal and interannual dynamics of the biomass and spatial distribution of a macrophyte meadow were explored in a Mediterranean coastal lagoon (Albufera des Grau, Balearic Islands) from 2002 to 2007. The dynamics in the main physicochemical variables were also analysed to assess the factors involved in the spatiotemporal variability of the submerged macrophytes. The meadows were dominated by Ruppia cirrhosa, which showed a marked seasonal cycle with winter quiescence and complete annual regrowth. The annual production of R. cirrhosa had high interannual variability and was amongst the highest described for this species in the literature, ranging 327-919 gDW m -2. The spatial distribution of macrophytes was determined by light availability and wave exposure, with the highest abundances found in shallow and gently sloped areas sheltered from the strong northerly winds. The interannual variations in macrophyte descriptors (area of occurrence, average depth of the meadows, and maximum biomass) were mainly related to water turbidity and salinity, but the effect of these variables was constrained to the spring and summer months, respectively. A significant negative correlation between the extent of coverage of R. cirrhosa and the water level at the end of the previous annual cycle was observed, suggesting a positive effect of desiccation on the extent of coverage of the macrophytes. After six years of apparent stability, the macrophytes abruptly disappeared from the lagoon. Although the mechanisms are not clear, this shift was likely attributable to a combination of several factors.

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.

An ultrasonic method for separation of epiphytic microbes from freshwater submerged macrophytes.

Science.gov (United States)

Cai, Xianlei; Gao, Guang; Yang, Jing; Tang, Xiangming; Dai, Jiangyu; Chen, Dan; Song, Yuzhi

2014-07-01

Epiphytic microbes are common inhabitants of freshwater submerged macrophytes, which play an important role in aquatic ecosystems. An important precondition for studying the epiphytic microbes is having an effective method of separating the attached microbes from the host macrophytes. We developed an ultrasound-based method for separating epiphytic microbes from freshwater submerged macrophytes, optimized the conditions of ultrasonic separation with an orthogonal experimental design, and compared the optimized ultrasonic method with manual separation. This method can be particularly useful for freshwater submerged macrophytes having a complex morphology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biological interactions in the co-occurrence of Eichhornia azurea and free-floating macrophytes - DOI: 10.4025/actascibiolsci.v31i4.5577

Directory of Open Access Journals (Sweden)

Sidinei Magela Thomaz

2009-08-01

Full Text Available The dynamic of plant communities is strongly influenced by biological interactions. We studied the effects of Eichhornia azurea on the growth of the free-floating macrophytes Eichhornia crassipes, Salvinia minima, Salvinia auriculata and Limnobium laevigatum. The experiments were carried out in three lakes of the upper Paraná river floodplain. We used 0.5 m side squares where these species grew for 11 days (S. auriculata and L. laevigatum and 17 days (E. crassipes and S. minima, in the presence and absence of E. azurea. There were no significant differences between the relative growth rates of macrophytes growing in the absence and presence of E. azurea. The relative interaction index showed the existence of competition between E. azurea and L. laevigatum, and neutrality with the other three species. There was no evidence of facilitation related to the improvement of physico-chemistry characteristics that could enhance macrophytes growth. However, we do not discard a ‘mechanical’ facilitation between E. azurea, which offers protection against wind and waves, and the other species of macrophytes

Size-dependent responses of zooplankton to submerged macrophyte restoration in a subtropical shallow lake

Science.gov (United States)

Zeng, Lei; He, Feng; Zhang, Yi; Liu, Biyun; Dai, Zhigang; Zhou, Qiaohong; Wu, Zhenbin

2018-03-01

To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans (cladocerans and copepods). The rotifers were grouped into three size classes (400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis (RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl- a, but negative correlations between macrophytes and COD or Chl- a, and between crustaceans and Chl- a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.

Have grass carp driven declines in macrophyte occurrence and ...

African Journals Online (AJOL)

The Vaal River, South Africa, historically had a rich diversity of native submerged macrophytes with at least 13 species from 5 families recorded. Over the past 10 years there has been a noticeable reduction in the occurrence and diversity of submerged macrophytes in the river. It is possible that this is linked to the recent ...

Macroinvertebrates associated with two submerged macrophytes ...

African Journals Online (AJOL)

Macroinvertebrates associated with two submerged macrophytes, Lagarosiphon ilicifolius and Vallisneria aethiopica , in the Sanyati Basin, Lake Kariba, Zimbabwe: effect of plant morphological complexity.

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.

Method for assessment and classification of water courses by using the community of aquatic macrophytes; Metodo per la valutazione e la classificazione dei corsi d'acqua utilizzando la comunita delle macrofite acquatiche

Energy Technology Data Exchange (ETDEWEB)

Minciardi, M R; Spada, C D; Rossi, G L; Angius, R; Orru, G [Sezione Biologia Ambientale e Conservazione della Natura Centro Ricerche Saluggia, ENEA, Vercelli (Italy); Mancini, L; Pace, G; Mercheggiani, S; Puccinelli, C [Dipt. di ambiente e connessa prevenzione primaria, Istituto Superiore di Sanita, Roma (Italy)

2009-07-01

Studies about aquatic macrophytes as bio indicator community in Europe have been carried out since 70s. Efficient macrophytes indices, mainly for the assessment of trophic state, have been defined in nineties. In 2000, WFD includes macrophytes among the ecological quality elements for running waters. To implement Directive 2000/60/C E, European countries had to define methodologies to evaluate the ecological status of water bodies by macrophytes assessment, but almost all Member States continue to use trophic indexes. Researches carried out in Italy during last 10 years confirm the presence and the evaluability in all river types, and the efficiency of macrophytes community as bio indicator. Besides, many European indices have been tested to assess their applicability throughout the country. Particularly, the Index Macrofitique Biologique en Riviere (IBMR), formalized in France in 2003 as trophic index and currently used as french national method, is applicable in Italy. This index not only allows to evaluate the trophic level metric, but can also be used, as proposed in France, as index of ecological status, expressed as distance from the expected trophic state. [Italian] In Europa, sin dagli anni '70, le macrofite acquatiche sono studiate come comunita bioindicatrice. E degli anni '90 la formalizzazione di Indici Macrofitici efficienti, soprattutto nella valutazione dello stato trofico. Nel 2000 la WFD include le macrofite tra gli elementi di qualita' ecologica per le acque correnti. Per il corretto recepimento della Direttiva 2000/60/CE i vari paesi europei hanno dovuto definire metodologie di valutazione stato ecologico dei corpi idrici in funzione dello stato della comunita' macrofitica, ma, in quasi tutti gli Stati membri si e continuato ad utilizzare anche indici macrofitici di stato trofico nell'ambito del monitoraggio dei corpi idrici. Le ricerche condotte in Italia negli ultimi 10 anni confermano la presenza di comunita' significative e valutabili in ogni

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.

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

of species expected from species-area relationships of artificial water bodies in rural areas. In urban areas, the number of macrophyte species was similar to artificial water systems in rural areas. Macrophyte species present in the study areas also were generally found within 20-30 km distance to the study...

Submerged macrophytes shape the abundance and diversity of bacterial denitrifiers in bacterioplankton and epiphyton in the Shallow Fresh Lake Taihu, China.

Science.gov (United States)

Fan, Zhou; Han, Rui-Ming; Ma, Jie; Wang, Guo-Xiang

2016-07-01

nirK and nirS genes are important functional genes involved in the denitrification pathway. Recent studies about these two denitrifying genes are focusing on sediment and wastewater microbe. In this study, we conducted a comparative analysis of the abundance and diversity of denitrifiers in the epiphyton of submerged macrophytes Potamogeton malaianus and Ceratophyllum demersum as well as in bacterioplankton in the shallow fresh lake Taihu, China. Results showed that nirK and nirS genes had significant different niches in epiphyton and bacterioplankton. Bacterioplankton showed greater abundance of nirK gene in terms of copy numbers and lower abundance of nirS gene. Significant difference in the abundance of nirK and nirS genes also existed between the epiphyton from different submerged macrophytes. Similar community diversity yet different community abundance was observed between epiphytic bacteria and bacterioplankton. No apparent seasonal variation was found either in epiphytic bacteria or bacterioplankton; however, environmental parameters seemed to have direct relevancy with nirK and nirS genes. Our study suggested that submerged macrophytes have greater influence than seasonal parameters in shaping the presence and abundance of bacterial denitrifiers. Further investigation needs to focus on the potential contact and relative contribution between denitrifiers and environmental factors.

A study of the seasonal dynamics of three phycoperiphytic communities, using nuclear track autoradiography. Pt. 2

International Nuclear Information System (INIS)

Pip, E.; Robinson, G.G.C.

1982-01-01

Net uptake of organic carbon, supplied as labelled glucose, fructose and sucrose, was examined for algal priphytic communities on Potamogeton richardsonii, P. praelongus and P. zosteriformis in a shallow lake. Nuclear track autoradiography was used to examine uptake for individual taxa comprising the communities. Net uptake rates per unit cell surface area were strongly correlated during the season for a few algal taxa in each community. The clusters of correlated taxa were different for each macrophyte. Principal component analysis of the species-time uptake matrix isolated 4 main components that accounted for > 99% of the seasonal variation on all 3 macrophytes. Multiple regression analysis of the rates of organic and inorganic uptake and log soluble host macrophyte carbohydrate showed highly significant relationships for these factors for some algae in some communities. Net productivity values with respect to total community cell surface area showed that the relative contribution of each taxon to community metabolism on a given macrophyte was similar in terms of both organic and inorganic carbon uptake. (orig.)

Colonization of leaf litter of two aquatic macrophytes, Mayaca fluviatilis Aublet and Salvinia auriculata Aublet by aquatic macroinvertebrates in a tropical reservoir

Directory of Open Access Journals (Sweden)

Marcia Cristina de Paula

2011-04-01

Full Text Available Decomposition and colonization of S. auriculata and M. fluviatilis by macroinvertebrates were analyzed during 40 days to determine whether differences existed on colonization by aquatic macroinvertebrates of two macrophytes with distinct habits (submerged versus fluctuant. Leaf litter of S. auriculata and M. fluviatilis were incubated in 24 litter bags (12 of each species, in a small reservoir surrounded by a cerrado fragment with low level of anthropic impact. After 10, 20, 30 and 40 days, the litter bags were removed and aquatic macroinvertebrates community was analyzed. Two hundred twenty macroinvertebrates were associated with S. auriculata and 261 were associated with M. fluviatilis, identified in 24 taxa. Both macrophyte species were colonized mainly by macroinvertebrate predators. Ablabesmyia with predator and collector food mechanisms was present in all sampling. The data showed an expressive increase of abundance during the process of decomposition and a decrease at the end of the experiment, in both macrophytes. Cluster analysis permitted inference that the colonization of the leaf liter by macroinvertebrates was determinated by incubation time of leaf litter not by the habit of macrophytes (submerged or fluctuant.

Functional and Taxonomic Differentiation of Macrophyte Assemblages Across the Yangtze River Floodplain Under Human Impacts.

Science.gov (United States)

Zhang, Min; García Molinos, Jorge; Zhang, Xiaolin; Xu, Jun

2018-01-01

Human activities and the consequent extirpations of species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. One of the main gaps in the assessment of biodiversity change in freshwater ecosystems is our limited understanding regarding how taxonomic and functional facets of macrophyte assemblages respond to human impacts on regional scales. Here, we assess the temporal (before 1970s against after 2000s) changes in taxonomic and functional richness and compositional dissimilarities, partitioned into its turnover and nestedness components, of freshwater macrophyte assemblages across the floodplain lakes of the Yangtze River in China. We found that functional and taxonomic assemblage differentiation occurred simultaneously under increasing human impact, concomitant to a general decrease in functional and taxonomic richness. However, this effect weakened when the historical level of taxonomic dissimilarity among assemblages was high. Macrophyte species with large dispersal range and submersed life form were significantly more susceptible to extirpation. The impact of human activities on differentiation was complex but habitat loss and fishery intensity were consistently the main drivers of assemblage change in these lakes, whereas water quality (i.e., light pollution and nutrient enrichment) had weaker effects. Further, macrophyte taxonomic and functional differentiation was mainly driven by the nestedness component of dissimilarity, accounting for changes in assemblage composition related to changes in species richness independent of species replacement. This result, markedly different from previous studies on freshwater fish assemblages conducted in these lakes, represents a novel contribution toward achieving a more holistic understanding of how human impacts contribute to shape community assemblages in natural ecosystems.

Impact of acidification and eutrophication on macrophyte communities in soft waters in The Netherlands

Energy Technology Data Exchange (ETDEWEB)

Roelofs, J G.M.

1983-01-01

During the last decades a strong decline has been noticed in the number of waters dominated by Littorellion species, mostly isoetids such as Lobelia dortmanna L., Isoetes lacustris L. and Littorella uniflora (L.) Aschers. Sixty-eight waters, which were known to be dominated by L. uniflora after 1950 were investigated. In 1980, L. uniflora appeared to be absent or to have strongly decreased in 53 (78%) of the waters. In 41 of them, Littorella had been replaced by submerged Juncus bulbosus L. and/or Sphagnum spp. These changes seem to have been caused by changed inorganic carbon budgets as a consequence of acidification. In the remaining 12 waters, eutrophication of the water and/or sediment seems to be responsible for the changes in the plant communities. Enrichment with phosphate of the mineral sediment alone, leads to luxurious growth of submerged, rooted macrophyte species such as Myriophyllum alterniflorum DC and Ranunculus peltatus Schrank, whereas phosphate-enrichment of both sediment and water leads to luxurious growth of pleustophytes such as Riccia fluitans L. and Lemna minor L. in small, shallow waters, and to plankton bloom and luxurious growth of epiphytes in larger, deeper waters. In these cases light limitation seems to be responsible for the disappearance or decline of the Littorellion species. 41 references, 1 figure, 4 tables.

PIXE analysis of chromium phytoaccumulation by the aquatic macrophytes Eicchornia crassipes

International Nuclear Information System (INIS)

Espinoza-Quinones, F.R.; Rizzutto, M.A.; Added, N.; Tabacniks, M.H.; Modenes, A.N.; Palacio, S.M.; Silva, E.A.; Rossi, F.L.; Martin, N.; Szymanski, N.

2009-01-01

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.

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.

Richness, biomass, and nutrient content of a wetland macrophyte community affect soil nitrogen cycling in a diversity-ecosystem functioning experiment

Science.gov (United States)

Korol, Alicia R.; Ahn, Changwoo; Noe, Gregory

2016-01-01

The development of soil nitrogen (N) cycling in created wetlands promotes the maturation of multiple biogeochemical cycles necessary for ecosystem functioning. This development proceeds from gradual changes in soil physicochemical properties and influential characteristics of the plant community, such as competitive behavior, phenology, productivity, and nutrient composition. In the context of a 2-year diversity experiment in freshwater mesocosms (0, 1, 2, 3, or 4 richness levels), we assessed the direct and indirect impacts of three plant community characteristics – species richness, total biomass, and tissue N concentration – on three processes in the soil N cycle – soil net ammonification, net nitrification, and denitrification potentials. Species richness had a positive effect on net ammonification potential (NAP) through higher redox potentials and likely faster microbial respiration. All NAP rates were negative, however, due to immobilization and high rates of ammonium removal. Net nitrification was inhibited at higher species richness without mediation from the measured soil properties. Higher species richness also inhibited denitrification potential through increased redox potential and decreased nitrification. Both lower biomass and/or higher tissue ratios of carbon to nitrogen, characteristics indicative of the two annual plants, were shown to have stimulatory effects on all three soil N processes. The two mediating physicochemical links between the young macrophyte community and microbial N processes were soil redox potential and temperature. Our results suggest that early-successional annual plant communities play an important role in the development of ecosystem N multifunctionality in newly created wetland soils.

Non-indigenous invertebrates, fish and macrophytes in Lake Garda (Italy

Directory of Open Access Journals (Sweden)

Cristina CAPPELLETTI

2011-08-01

Full Text Available As observed in many countries, lakes are involved in an important process of colonization by non-indigenous species (NIS. Since 1725, 37 species of non-indigenous fish, invertebrates and macrophytes have been recorded in Lake Garda, the largest Italian lake. This phenomenon is particularly important for invertebrates and macrophytes, as their pathways of introduction are accidental. Recently among the 100 Worst Invasive Alien Species in Europe, the invertebrates Corbicula fluminea, Dikerogammarus villosus and Procambarus clarkii, and the macrophytes Lagarosiphon major, Elodea nuttallii and Elodea canadensis have been recorded in Lake Garda. In order to define the present status of non-indigenous species in Lake Garda, published and unpublished data were reviewed.

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.

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

A study of the seasonal dynamics of three phycoperiphytic communities using nuclear track autoradiography. Pt. 1

International Nuclear Information System (INIS)

Pip, E.; Robinson, G.G.C.

1982-01-01

Net inorganic carbon uptake was examined for algal periphytic communities on Potamogeton richardsonii, P. praelongus and P. zosteriformis in a shallow lake. Nuclear track autoradiography was used to examine uptake for individual taxa comprising the communities. Net uptake rates per unit cell surface area were strongly correlated during the season for certain algal taxa, particularly diatoms, on the same macrophyte. The correlated taxa formed a different correlation cluster for each macrophyte. Although several of the same algal taxa appeared in the correlation clusters for different macrophytes, the behavior of a given taxon was only rarely correlated on different macrophytes. Each cluster behaved as an independent unit. Such organized behavior may be important in algal succession. Principal component analysis of the species-time uptake matrix isolated 3 main principal components that accounted for > 95% of the seasonal variation on all 3 macrophytes. (orig.)

Checklist of the Aquatic Macrophytes

African Journals Online (AJOL)

Professor, Department of Plant Science, Obafemi Awolowo University, Ile Ife, Osun State. 3. Professor, Department of Botany, Obafemi Awolowo University, Ile Ife, Osun State. (Received: October, 2010; Accepted: May, 2011). The occurrence and diversity of aquatic macrophytes on Jebba Lake were documented during the ...

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

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.

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

Science.gov (United States)

Rolon, Ana Silvia; Rocha, Odete; Maltchik, Leonardo

2013-03-01

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.

Shade and flow effects on ammonia retention in macrophyte-rich streams: implications for water quality

International Nuclear Information System (INIS)

Wilcock, Robert J.; Scarsbrook, Mike R.; Cooke, James G.; Costley, Kerry J.; Nagels, John W.

2004-01-01

Controlled releases of NH 4 -N and conservative tracers (Br - and Cl - ) to five reaches of four streams with contrasting macrophyte communities have shown differing retentions, largely as a result of the way plants interact with stream flow and velocity. First-order constants (k) were 1.0-4.8 d -1 and retention of NH 4 -N was 6-71% of amounts added to each reach. Distance travelled before a 50% reduction in concentration was achieved were 40-450 m in three streams under low-flow conditions, and 2400-3800 m at higher flows. Retention (%) of NH 4 -N can be approximated by a simple function of travel time and k, highlighting the importance of the relationship between macrophytes and stream velocity on nutrient processing. This finding has significant management implications, particularly with respect to restoration of riparian shade. Small streams with predominantly marginal emergent plants are likely to have improved retention of NH 4 -N as a result of shading or other means of reducing plant biomass. Streams dominated by submerged macrophytes will have impaired NH 4 -N retention if plant biomass is reduced because of reduced contact times between NH 4 -N molecules and reactive sites. In these conditions water resource managers should utilise riparian shading in concert with unshaded vegetated reaches to achieve a balance between enhanced in-stream habitat and nutrient processing capacity

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.

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

Science.gov (United States)

Mormul, Roger Paulo; Ferreira, Fernando Alves; Michelan, Thaisa Sala; Carvalho, Priscilla; Silveira, Marcio José; Thomaz, Sidinei Magela

2010-12-01

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 surveys should be

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

The structuring role of submerged macrophytes in a large subtropical shallow lake

NARCIS (Netherlands)

Finkler Ferreira, Tiago; Crossetti, Luciane O.; Motta Marques, David M.L.; Cardoso, Luciana; Fragoso, Carlos Ruberto; Nes, van Egbert H.

2018-01-01

It is well known that submerged macrophytes exert positive feedback effects that enhance the water transparency, stabilizing the clear-water state in shallow temperate lakes. However, the structuring effect of macrophytes on the food web of subtropical and tropical ecosystems is still poorly

FATTY ACID SIGNATURES DIFFERENTIATE MARINE MACROPHYTES AT ORDINAL AND FAMILY RANKS(1).

Science.gov (United States)

Galloway, Aaron W E; Britton-Simmons, Kevin H; Duggins, David O; Gabrielson, Paul W; Brett, Michael T

2012-08-01

Primary productivity by plants and algae is the fundamental source of energy in virtually all food webs. Furthermore, photosynthetic organisms are the sole source for ω-3 and ω-6 essential fatty acids (EFA) to upper trophic levels. Because animals cannot synthesize EFA, these molecules may be useful as trophic markers for tracking sources of primary production through food webs if different primary producer groups have different EFA signatures. We tested the hypothesis that different marine macrophyte groups have distinct fatty acid (FA) signatures by conducting a phylogenetic survey of 40 marine macrophytes (seaweeds and seagrasses) representing 36 families, 21 orders, and four phyla in the San Juan Archipelago, WA, USA. We used multivariate statistics to show that FA composition differed significantly (P macrophytes confirmed that this pattern was robust on a global scale (P macrophyte taxa shows a clear relationship between macrophyte phylogeny and FA content and strongly suggests that FA signature analyses can offer a viable approach to clarifying fundamental questions about the contribution of different basal resources to food webs. Moreover, these results imply that taxa with commercially valuable EFA signatures will likely share such characteristics with other closely related taxa that have not yet been evaluated for FA content. © 2012 Phycological Society of America.

Archaea Dominate the Ammonia-Oxidizing Community in the Rhizosphere of the Freshwater Macrophyte Littorella uniflora

DEFF Research Database (Denmark)

Herrmann, Martina; Saunders, Aaron M.; Schramm, Andreas

2008-01-01

Archaeal and bacterial ammonia monooxygenase genes (amoA) had similar low relative abundances in freshwater sediment. In the rhizosphere of the submersed macrophyte Littorella uniflora, archaeal amoA was 500- to >8,000-fold enriched compared to bacterial amoA, suggesting that the enhanced nitrifi...

Hydroponic Uptake of Atrazine and Lambda-cyhalothrin in Aquatic Macrophytes

Science.gov (United States)

Bouldin, J. L.; Farris, J. L.; Moore, M. T.; Smith, S.; Cooper, C. M.

2005-05-01

Phytoremediation encompasses an array of plant-associated processes known to mitigate contaminants from soil, sediment, and water. Modification of pesticides associated with agricultural runoff includes processes directly associated with aquatic macrophytes in addition to soil geochemical modifications and associated rhizospheric degradation. Remediation attributes of two vegetative species common to agricultural drainages in the Mississippi Delta, USA, were assessed using atrazine and lambda-cyhalothrin. Concentrations used in 8-d hydroponic exposures were calculated using recommended field applications and a 5% runoff model from a 0.65-cm rainfall event on a 2.02-ha field. While greater atrazine uptake was measured in Juncus effusus, greater lambda-cyhalothrin uptake occurred in Ludwigia peploides. Maximum pesticide uptake was reached within 48 h for each exposure and subsequent translocation of pesticides to upper plant biomass occurred in macrophytes exposed to atrazine. Sequestration of 98.2% of lambda-cyhalothrin in roots of L. peploides was measured after 8 d. Translocation of lambda-cyhalothrin in J. effusus resulted in 25.4% of pesticide uptake partitioned to upper plant biomass. These individual macrophyte remediation studies measured species- and pesticide-specific uptake rates, indicating that the seasonality of pesticide applications and macrophyte emergence might interact strongly to enhance mitigation capabilities in edge-of-field conveyance structures.

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.

Xylanase and cellulase activities during anaerobic decomposition of three aquatic macrophytes.

Science.gov (United States)

Nunes, Maíra F; da Cunha-Santino, Marcela B; Bianchini, Irineu

2011-01-01

Enzymatic activity during decomposition is extremely important to hydrolyze molecules that are assimilated by microorganisms. During aquatic macrophytes decomposition, enzymes act mainly in the breakdown of lignocellulolytic matrix fibers (i.e. cellulose, hemicellulose and lignin) that encompass the refractory fraction from organic matter. Considering the importance of enzymatic activities role in decomposition processes, this study aimed to describe the temporal changes of xylanase and cellulose activities during anaerobic decomposition of Ricciocarpus natans (freely-floating), Oxycaryum cubense (emergent) and Cabomba furcata (submersed). The aquatic macrophytes were collected in Óleo Lagoon, Luiz Antonio, São Paulo, Brazil and bioassays were accomplished.  Decomposition chambers from each species (n = 10) were set up with dried macrophyte fragments and filtered Óleo Lagoon water. The chambers were incubated at 22.5°C, in the dark and under anaerobic conditions. Enzymatic activities and remaining organic matter were measured periodically during 90 days. The temporal variation of enzymes showed that C. furcata presented the highest decay and the highest maximum enzyme production. Xylanase production was higher than cellulase production for the decomposition of the three aquatic macrophytes species.

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

New insights on the species-specific allelopathic interactions between macrophytes and marine HAB dinoflagellates.

Directory of Open Access Journals (Sweden)

Hela Ben Gharbia

Full Text Available 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.

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.

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

Monitoring of selenium in macrophytes - the case of Slovenia.

Science.gov (United States)

Mechora, Špela; Germ, Mateja; Stibilj, Vekoslava

2014-09-01

This paper examines macrophytes from various locations in Slovenian streams for selenium (Se) content in an attempt to discover if Se contamination is present and if Se uptake varies between sampling sites. For this purpose, macrophytes and water from ten locations in the Notranjska and Central regions (Slovenia) with different land use in the catchment were sampled. To assess the environmental conditions of the streams the Riparian, Channel, and Environment (RCE) inventory was applied, which revealed that investigated stretches of streams fall into RCE classes III, IV and V. The concentration of Se in water at all locations was less than 1μgSeL(-1). The Se content in macrophytes differed between sampling sites, with the highest content of Se in samples from Žerovniščica stream and the lowest in samples from Lipsenjščica stream. The content of Se was the highest in moss samples (3038ngSeg(-1) DM) and in the amphibious species Veronica anagallis-aquatica (1507ngSeg(-1) DM). Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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

International Nuclear Information System (INIS)

Knauert, Stefanie; Singer, Heinz; Hollender, Juliane; Knauer, Katja

2010-01-01

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.

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.

Macrophytes in the cooling ponds of Ukrainian nuclear and thermal power plants

International Nuclear Information System (INIS)

D'yachenko, T.N.

2013-01-01

Attention is focused at the macrophytes role in the functioning of the natural-technological cooling ponds ecosystems, at the features of aquatic plants and station water supply system interaction. It was considered the degree of macrophytes scrutiny and it was pointed out the necessity of monitoring and controlling their condition in the cooling ponds of Ukrainian power plants.

Capabilities of Seven Species of Aquatic Macrophytes for Phytoremediation of Pentachlorophenol Contaminated Sediment

Science.gov (United States)

Zhao, Liangyuan; Guo, Weijie; Li, Qingyun; Li, Huan; Zhao, Weihua; Cao, Xiaohuan

2017-01-01

Sediments are regarded as the ultimate sink of pentachlorophenol(PCP) in aquatic environment, and capabilities of seven species of aquatic macrophytes for remediating PCP contaminated sediment were investigated. Seven species of aquatic macrophytes could significantly accelerate the degradation of PCP in sediments. Among all, canna indica L., Acorus calamus L. and Iris tectorum Maxim. can be used as efficient alternative plants for remediation of PCP contaminated sediment, which attained 98%, 92% and 88% of PCP removal in sediments, respectively. PCP was detected only in root tissues and the uptake was closely related to the root lipid contents of seven plants. The presence of seven aquatic macrophytes significantly increased microbial populations and the activities of dehydrogenase compared with control sediments, indicating that rhizosphere microorganism played important role in the remediation process. In conclusion, seven species of aquatic macrophytes may act as promising tools for the PCP phytoremediation in aquatic environment, especially Canna indica L., Acorus calamus L. and Iris tectorum Maxim.

Concordance between macrophytes and macroinvertebrates in a Mediterranean river of central Apennine region.

Science.gov (United States)

Traversetti, Lorenzo; Scalici, Massimiliano; Ginepri, Valeria; Manfrin, Alessandro; Ceschin, Simona

2014-05-01

The main aim of this study was to improve the knowledge about the concordance among macrophytes and macroinvertebrates to provide complementary information and facilitate the procedures for quality assessment of river ecosystems. Macrophytes and macroinvertebrates were collected in 11 sampling sites along a central Apennine calcareous river in October 2008 and June 2009. The concordance between the two biomonitoring groups was tested according to several environmental parameters. The comparison of data matrix similarities by Mantel test showed differences in the assemblage of macrophytes and macroinvertebrates along the river since correlation values were 0.04, p > 0.05 in October 2008 and 0.39, p > 0.05 in June 2009. The study revealed lack of concordance between the two groups, emphasizing that the information provided by macrophytes and macroinvertebrates does not overlap in terms of response to environmental parameters. Indeed, the two different biological groups resulted useful descriptors of different parameters. Together, they could represent a complementary tool to reflect the river environmental quality.

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

Macrophyte species distribution, indices of biotic integrity and sampling intensity in isolated Florida marshes

Science.gov (United States)

This study tested macrophyte condition metrics calculated after decreasing the effort and area of sampling by 33% to 66%, as tested in 74 emergent isolated wetlands. Four belted transects from wetland edge to center were established and rooted macrophytes were identified. The eff...

Bioprospecting of Marine Macrophytes Using MS-Based Lipidomics as a New Approach.

Science.gov (United States)

Maciel, Elisabete; Costa Leal, Miguel; Lillebø, Ana Isabel; Domingues, Pedro; Domingues, Maria Rosário; Calado, Ricardo

2016-03-08

The marine environment supports a remarkable diversity of organisms which are a potential source of natural products with biological activities. These organisms include a wide variety of marine plants (from micro- to macrophytes), which have been used in the food and pharmaceutical industry. However, the biochemistry and biological activities of many of these macrophytes (namely macroalgae and halophytes, including seagrasses) are still far from being fully explored. Most popular bioactive components include polysaccharides, peptides, phenolics and fatty acids (FAs). Polar lipids (glycolipids, phospholipids and betaine lipids) are emerging as novel value-added bioactive phytochemicals, rich in n-3 FA, with high nutritional value and health beneficial effects for the prevention of chronic diseases. Polar lipids account various combinations of polar groups, fatty acyl chains and backbone structures. The polar lipidome of macrophytes is remarkably diverse, and its screening represents a significant analytical challenge. Modern research platforms, particularly mass spectrometry (MS)-based lipidomic approaches, have been recently used to address this challenge and are here reviewed. The application of lipidomics to address lipid composition of marine macrophytes will contribute to the stimulation of further research on this group and foster the exploration of novel applications.

Bioprospecting of Marine Macrophytes Using MS-Based Lipidomics as a New Approach

Directory of Open Access Journals (Sweden)

Elisabete Maciel

2016-03-01

Full Text Available The marine environment supports a remarkable diversity of organisms which are a potential source of natural products with biological activities. These organisms include a wide variety of marine plants (from micro- to macrophytes, which have been used in the food and pharmaceutical industry. However, the biochemistry and biological activities of many of these macrophytes (namely macroalgae and halophytes, including seagrasses are still far from being fully explored. Most popular bioactive components include polysaccharides, peptides, phenolics and fatty acids (FAs. Polar lipids (glycolipids, phospholipids and betaine lipids are emerging as novel value-added bioactive phytochemicals, rich in n-3 FA, with high nutritional value and health beneficial effects for the prevention of chronic diseases. Polar lipids account various combinations of polar groups, fatty acyl chains and backbone structures. The polar lipidome of macrophytes is remarkably diverse, and its screening represents a significant analytical challenge. Modern research platforms, particularly mass spectrometry (MS-based lipidomic approaches, have been recently used to address this challenge and are here reviewed. The application of lipidomics to address lipid composition of marine macrophytes will contribute to the stimulation of further research on this group and foster the exploration of novel applications.

Analysis of the impact of water level fluctuations on macrophytes in Miyun Reservoir after receiving water transferred by the South-to-North Water Diversion Project

Science.gov (United States)

Yu, L.; Gu, H.; Lou, C. H.; Zhang, L.; Meng, Q. Y.

2016-08-01

As the main primary producers in aquatic ecosystems, macrophytes affect the structure and function of aquatic ecosystems, and their distribution is controlled by water depth. Miyun Reservoir in Beijing will have to experience substantial changes in water level and surface area as it begins to receive water transferred by the South-to-North Water Diversion Project, which will have an adverse impact on the macrophytes growing there. In this study, a hydrodynamic model was constructed with MIKE21 and then used in a simulation in three scenarios: dry year, normal year and wet year. The results suggest that during water diversion, the annual and interannual water level fluctuations will be too significant for them to adapt and as a result, the original macrophytes in the reservoir tend to die and disappear completely. The area of the zone suitable for macrophyte growth, or suitable growth zone (SGZ), fluctuated. Restricted by the main dam and auxiliary dam to its south, the overall suitable growth zone moved toward the northeast and northwest of the reservoir, with a northeastward movement of its centroid. The distance and path of movement varied between scenarios. After the water diversion was completed, the suitable growth zone shrunk in the three scenarios. It is predicted that the macrophyte species diversity and richness of the reservoir can recover to the levels recorded before water diversion only in dry year. These results suggest that manual interventions should be implemented after water diversion to speed up the natural recovery of aquatic plant communities in Miyun Reservoir and thereby maintain the stability of the aquatic ecosystem.

Can aquatic macrophytes mobilize technetium by oxidizing their rhizosphere?

International Nuclear Information System (INIS)

Sheppard, S.C.; Evenden, W.G.

1991-01-01

Technetium (Tc) is very mobile in aerated surface environments, but is essentially immobile and biologically unavailable in anaerobic sediments. Aquatic macrophyte roots penetrate anaerobic sediments, carrying O 2 downward and frequently creating oxidizing conditions in their rhizosphere. The authors hypothesized that this process could mobilize otherwise unavailable Tc, possibly leading to incorporation of Tc into human or animal foods. Through experiments with rice (Oryza sativa L.), and with a novel artificial macrophyte root, they concluded that this pathway is unlikely to be important for annual plants, especially in soils with a high biological oxygen demand. The relatively slow oxidation of Tc limited its mobilization by short-lived root systems

Studies on the treatment efficiency of sediment phosphorus with a combined technology of PCFM and submerged macrophytes.

Science.gov (United States)

Zhang, Yi; He, Feng; Xia, Shibin; Zhou, Qiaohong; Wu, Zhenbin

2015-11-01

The removal efficiency of sediment phosphorus (P) in all fractions with a combined technology of porous ceramic filter media (PCFM) and submerged macrophytes was studied in Donghu Lake, Wuhan, China. The adsorption kinetic models of the sediment P in all fractions on PCFM could be described well by a power function equations (Qt = k · t(a), 0 macrophyte, was higher for all P forms than that of the combination of PCFM and another macrophyte, Vallisneria spiralis. This study suggested that the combination of PCFM and macrophytes could achieve a synergetic sediment P removal because the removal rates of the combinations were higher than the sum of that of PCFM and macrophytes used separately. The combined technology could be further applied to treat internal P loading in eutrophic waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experiments in water-macrophyte systems to uncover the dynamics of pesticide mitigation processes in vegetated surface waters/streams.

Science.gov (United States)

Stang, Christoph; Bakanov, Nikita; Schulz, Ralf

2016-01-01

Knowledge on the dynamics and the durability of the processes governing the mitigation of pesticide loads by aquatic vegetation in vegetated streams, which are characterized by dynamic discharge regimes and short chemical residence times, is scarce. In a static long-term experiment (48 h), the dissipation of five pesticides from the aqueous phase followed a biphasic pattern in the presence of aquatic macrophytes. A dynamic concentration decrease driven by sorption to the macrophytes ranged from 8.3 to 60.4% for isoproturon and bifenox, respectively, within the first 2 h of exposure. While the aqueous concentrations of imidacloprid, isoproturon, and tebufenozide remained constant thereafter, the continuous but decelerated concentration decrease of difenoconazole and bifenox in the water-macrophyte systems used here was assumed to be attributed to macrophyte-induced degradation processes. In addition, a semi-static short-term experiment was conducted, where macrophytes were transferred to uncontaminated medium after 2 h of exposure to simulate a transient pesticide peak. In the first part of the experiment, adsorption to macrophytes resulted in partitioning coefficients (logK D_Adsorp) ranging from 0.2 for imidacloprid to 2.2 for bifenox. One hour after the macrophytes were transferred to the uncontaminated medium, desorption of the compounds from the macrophytes resulted in a new phase equilibrium and K D_Desorp values of 1.46 for difenoconazole and 1.95 for bifenox were determined. A correlation analysis revealed the best match between the compound affinity to adsorb to macrophytes (expressed as K D_Adsorp) and their soil organic carbon-water partitioning coefficient (K OC) compared to their octanol-water partitioning coefficient (K OW) or a mathematically derived partitioning coefficient.

Silica uptake in aquatic and wetland macrophytes: a strategic choice between silica, lignin and cellulose?

Science.gov (United States)

Schoelynck, Jonas; Bal, Kris; Backx, Hans; Okruszko, Tomasz; Meire, Patrick; Struyf, Eric

2010-04-01

*Although silica (Si) is not an essential element for plant growth in the classical sense, evidence points towards its functionality for a better resistance against (a)biotic stress. Recently, it was shown that wetland vegetation has a considerable impact on silica biogeochemistry. However, detailed information on Si uptake in aquatic macrophytes is lacking. *We investigated the biogenic silica (BSi), cellulose and lignin content of 16 aquatic/wetland species along the Biebrza river (Poland) in June 2006 and 2007. The BSi data were correlated with cellulose and lignin concentrations. *Our results show that macrophytes contain significant amounts of BSi: between 2 and 28 mg BSi g(-1). This is in the same order of magnitude as wetland species (especially grasses). Significant antagonistic correlations were found between lignin, cellulose and BSi content. Interestingly, observed patterns were opposite for wetland macrophytes and true aquatic macrophytes. *We conclude that macrophytes have an overlooked but potentially vast storage capacity for Si. Study of their role as temporal silica sinks along the land-ocean continuum is needed. This will further understanding of the role of ecosystems on land ocean transport of this essential nutrient.

Studies on the treatment efficiency of sediment phosphorus with a combined technology of PCFM and submerged macrophytes

International Nuclear Information System (INIS)

Zhang, Yi; He, Feng; Xia, Shibin; Zhou, Qiaohong; Wu, Zhenbin

2015-01-01

The removal efficiency of sediment phosphorus (P) in all fractions with a combined technology of porous ceramic filter media (PCFM) and submerged macrophytes was studied in Donghu Lake, Wuhan, China. The adsorption kinetic models of the sediment P in all fractions on PCFM could be described well by a power function equations (Q t  = k · t a , 0 < a < 1). The P removal capacity of the combination of PCFM and Potamogeton crispus, a submerged macrophyte, was higher for all P forms than that of the combination of PCFM and another macrophyte, Vallisneria spiralis. This study suggested that the combination of PCFM and macrophytes could achieve a synergetic sediment P removal because the removal rates of the combinations were higher than the sum of that of PCFM and macrophytes used separately. The combined technology could be further applied to treat internal P loading in eutrophic waters. - Highlights: • PCFM were tested as novel sorbents for sediment P in all fractions removal. • Adsorption kinetic models of sediment P on PCFM could be described by power function equations. • Combination of PCFM and macrophytes could achieve a synergetic sediment P removal. • Combined technology could be further applied to treat internal P loading in eutrophic waters. - The combination of PCFM and macrophytes could achieve a synergetic sediment P removal because the removal rates of the combinations were higher than the sum of that used separately.

Distribution of 238Pu and 239240Pu in aquatic macrophytes from a midwestern watershed

International Nuclear Information System (INIS)

Wayman, C.W.; Bartelt, G.E.; Alberts, J.J.

1977-01-01

Aquatic macrophytes were collected in the Great Miami River, Ohio, above and below Miamisburg and in the canal and ponds, near the Mound Laboratory, which contain sediments of a high activity (approximately 10 3 to 10 6 times) relative to the river sediments. Macrophytes collected in the river below Miamisburg have higher activities of 238 Pu than those collected from above the city. Macrophytes from the canal and ponds contain high specific activities of 238 Pu and 239 , 240 Pu with the exception of cattails grown in the ponds. Concentration factors are reported and discussed with reference to possible modes of plutonium accumulation and distribution within the plants

[Influence of submerged macrophytes on phosphorus transference between sediment and overlying water in the growth period].

Science.gov (United States)

Wang, Li-Zhi; Wang, Guo-Xiang; Yu, Zhen-Fei; Zhou, Bei-Bei; Chen, Qiu-Min; Li, Zhen-Guo

2012-02-01

In order to study the process of phosphorus transfer between sediment and overlying water, Hydrilla verticillata and Vallisneria natans were cultured in spring, Potamogeton crispus was cultured in winter. Changes of environmental factors and phosphorus concentrations in water and sediment were investigated. The results indicated that: submerged macrophytes could reduce all phosphorus fractions in the overlying water. Phosphorus concentrations in overlying water maintained in a relative low level in the growth period of submerged macrophytes. The concentrations of total phosphorus (TP) in overlying water of H. verticillata, V. natans and P. crispus were 0.03-0.05, 0.04-0.12, 0.02-0.11 mg x L(-1), respectively. All phosphorus fractions in sediment were reduced. The maximum value between submerged macrophyte and control of H. verticillata, V. natans and P. crispus were 35.34, 60.67 and 25.92 mg x kg(-1), respectively. Dissolved oxygen (DO), redox potential (Eh) and pH in overlying water increased (DO 10.0-14.0 mg x L(-1), Eh 185-240 mV, pH 8.0-11.0) in the submerged macrophytes groups. Submerged macrophytes increased Eh( -140 - -23 mV) and maintained pH(7.2-8.0) in neutral range. The results indicated that submerged macrophytes affected phosphorus transferring between sediment and overlying water through increasing DO, Eh and pH in overlying water, and Eh in sediment.

A propos de l'EQB macrophytes en cours d'eau dans les DOM : Note

OpenAIRE

Chauvin, C.

2015-01-01

/ Cette note présente les éléments essentiels ressortis de la mission "macrophytes" 2012-2013menée dans les DOM, en ce qui concerne la pertinence et la faisabilité d'un indicateur d'état écologique en cours d'eau basé sur les macrophytes.

Assessing the effectiveness of pollutant removal by macrophytes in a floating wetland for wastewater treatment

Science.gov (United States)

Prajapati, Meera; van Bruggen, Johan J. A.; Dalu, Tatenda; Malla, Rabin

2017-12-01

The study aimed to evaluate the removal of pollutants by floating treatment wetlands (FTWs) using an edible floating plant, and emergent macrophytes. All experiments were performed under ambient conditions. Physico-chemical parameters were measured, along with microbiological analysis of biofilm within the roots, water column, and sludge and gravel zone. Nitrification and denitrification rates were high in the water zone of Azolla filiculoides, Lemna minor, Lactuca sativa, P. stratiotes, and Phragmites australis. Phosphate removal efficiencies were 23, 10, and 15% for the free-floating hydrophytes, emergent macrophytes, and control and edible plants, respectively. The microbial community was relatively more active in the root zone compared to other zones. Pistia stratiotes was found to be the efficient in ammonium (70%) and total nitrogen (59%) removal. Pistia stratiotes also showed the highest microbial activity of 1306 mg day-1, which was 62% of the total volume. Microbial activity was found in the water zone of all FTWs expect for P. australis. The use of P. stratiotes and the edible plant L. sativa could be a potential option to treat domestic wastewater due to relatively high nutrient and organic matter removal efficiency.

Mitigating with macrophytes: submersed plants reduce the toxicity of pesticide-contaminated water to zooplankton.

Science.gov (United States)

Brogan, William R; Relyea, Rick A

2013-03-01

In ecotoxicology, appreciation is growing for the influence that ecological interactions have on the toxicity of contaminants, such as insecticides, to sensitive species. Most previous studies, however, have focused on factors that exacerbate insecticide effects on species, while factors that may mitigate these effects have been relatively ignored. In aquatic habitats, a small number of studies have shown that submersed macrophytes can remove some insecticides from the water column via sorption. Although examining sorption dynamics is important for understanding the environmental fate of insecticides, whether and to what extent macrophytes actually mitigate insecticide effects on aquatic species remains unknown. In the present study, the authors examined how much and how quickly several realistic densities of the macrophyte Elodea canadensis decreased the toxicity of the insecticide malathion to Daphnia magna, a keystone aquatic herbivore. To do this, the authors quantified Daphnia survival in outdoor test systems (0.95 L) exposed to a factorial combination of five Elodea densities crossed with five malathion concentrations. The authors discovered that malathion's lethality to Daphnia decreased with increasing Elodea density. Furthermore, the rate at which Elodea reduced malathion's toxicity in the water column increased with macrophyte density. These results provide strong evidence that submersed macrophytes can mitigate the ecological impacts of a popular insecticide and further support that ecological interactions can strongly influence contaminant environmental effects. Copyright © 2013 SETAC.

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

Science.gov (United States)

Diepens, Noël J; Arts, Gertie H P; Focks, Andreas; Koelmans, Albert A

2014-10-21

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 modeling chemical flows of chlorpyrifos, linuron, and six PCBs in water-sediment-macrophyte systems. Chemical fluxes across the interfaces between pore water, overlying water, shoots, and roots were modeled using a novel multicompartment model. The modeling yielded the first mass-transfer parameter set reported for bioaccumulation by sediment-rooted macrophytes, with satisfactory narrow confidence limits for more than half of the estimated parameters. Exposure via the water column led to rapid uptake by Elodea canadensis and Myriophyllum spicatum shoots, followed by transport to the roots within 1-3 days, after which tissue concentrations gradually declined. Translocation played an important role in the exchange between shoots and roots. Exposure via spiked sediment led to gradual uptake by the roots, but subsequent transport to the shoots and overlying water remained limited for the chemicals studied. These contrasting patterns show that exposure is sensitive to test set up, chemical properties, and species traits. Although field-concentrations in water and sediment will differ from those in the tests, the model parameters can be assumed applicable for modeling exposure to macrophytes in the field.

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

African Journals Online (AJOL)

Effect of paclobutrazol on three different aquatic macrophytes under in vitro monoculture or polyculture conditions. Kitti Bodhipadma, Sompoch Noichinda, Thanaphol Maneeruang, Koravisd Nathalang, Luepol Punnakanta, David WM Leung ...

Variability of pesticide exposure in a stream mesocosm system: Macrophyte-dominated vs. non-vegetated sections

Energy Technology Data Exchange (ETDEWEB)

Beketov, Mikhail A. [UFZ - Helmholtz Centre for Environmental Research, Department of System Ecotoxicology, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: mikhail.beketov@ufz.de; Liess, Matthias [UFZ - Helmholtz Centre for Environmental Research, Department of System Ecotoxicology, Permoserstrasse 15, D-04318 Leipzig (Germany)

2008-12-15

For flowing water bodies no information is available about patterns of contaminant distribution in flowing water compared to macrophyte-dominated structures. The aim of the study was to examine temporal dynamic and spatial cross-channel variability of pulse exposure of the insecticide thiacloprid in outdoor stream mesocosms. Two distinct cross-channel sections have been considered: macrophyte-dominated littoral and non-vegetated midstream. Median disappearance time ranged from 17 to 43 h (water phase, midstream). We showed that during the exposure pulse (10 h) thiacloprid concentrations in the macrophyte-dominated section were 20-60% lower than those in the non-vegetated section. This suggests that spatial variability in contaminant concentrations, particularly in streams containing macrophytes, should be taken into account to enable a more realistic assessment of (i) exposure and associated effects and (ii) mass transport of pesticides and other chemicals into river systems (e.g. losses with surface runoff). - Spatial cross-channel variability of contaminant concentrations is noteworthy and important.

Variability of pesticide exposure in a stream mesocosm system: Macrophyte-dominated vs. non-vegetated sections

International Nuclear Information System (INIS)

Beketov, Mikhail A.; Liess, Matthias

2008-01-01

For flowing water bodies no information is available about patterns of contaminant distribution in flowing water compared to macrophyte-dominated structures. The aim of the study was to examine temporal dynamic and spatial cross-channel variability of pulse exposure of the insecticide thiacloprid in outdoor stream mesocosms. Two distinct cross-channel sections have been considered: macrophyte-dominated littoral and non-vegetated midstream. Median disappearance time ranged from 17 to 43 h (water phase, midstream). We showed that during the exposure pulse (10 h) thiacloprid concentrations in the macrophyte-dominated section were 20-60% lower than those in the non-vegetated section. This suggests that spatial variability in contaminant concentrations, particularly in streams containing macrophytes, should be taken into account to enable a more realistic assessment of (i) exposure and associated effects and (ii) mass transport of pesticides and other chemicals into river systems (e.g. losses with surface runoff). - Spatial cross-channel variability of contaminant concentrations is noteworthy and important

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

Water table and species identity outweigh carbon and nitrogen availability in a softwater plant community

Science.gov (United States)

Vanderhaeghe, Floris; Smolders, Alfons J. P.; Roelofs, Jan G. M.; Hoffmann, Maurice

2013-02-01

Performance of aquatic macrophytes is driven by many environmental factors, and a major challenge is to understand how aquatic macrophyte communities are structured in various environments. In softwater lakes in Western Europe, hydrological state (submersed/emersed), carbon dioxide and ammonium levels and species interactions are considered as driving forces in structuring amphibious plant communities. In this study we aimed at evaluating the relative importance of these factors for four species in a competitive neighbourhood. Softwater lake habitat was simulated during one growing season in laboratory conditions, mimicking water level fluctuation, photoperiod and temperature. Artificial communities consisted of small populations of four softwater macrophyte species: Luronium natans, Baldellia ranunculoides ssp. repens, Eleocharis multicaulis and Hydrocotyle vulgaris. These communities were subjected to two levels of carbon dioxide and ammonium. Additionally, monocultures of Baldellia and Eleocharis were grown at a higher nutrient level combination in order to measure their competitive response in a community. Time (hydrological state) and species identity turned out to be the only consistently significant factors determining community composition. Plant performance was clearly species-dependent, while carbon dioxide and ammonium did not have major effects. The competitive response was significant in both Eleocharis and Baldellia. Competition intensity was highest in the emersed state. Carbon dioxide had a supplementary effect on the within-species performance in Luronium, Baldellia and Eleocharis, with high carbon dioxide level mainly resulting in more flowers and more stolons. Community outcomes and competitive responses in aquatic macrophytes appear difficult to predict, because of mixed life strategies and morphological and functional plasticity. We conclude that hydrological state was the only important environmental factor. The identity of the species that

Cadmium and chromium removal kinetics from solution by two aquatic macrophytes

International Nuclear Information System (INIS)

Sune, N.; Sanchez, G.; Caffaratti, S.; Maine, M.A.

2007-01-01

The aim of this work was to determine chromium and cadmium bioaccumulation processes of two free-floating macrophytes commonly used in wetlands for water treatment: Salvinia herzogii and Pistia stratiotes. Metal removal from the solution involves two stages: a fast one and a slow one. The fast stage of the Cd uptake is significantly different for each species, while it is not significantly different in Cr uptake. The most important processes of Cd uptake are biological ones in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes. The main processes of Cr uptake in both macrophytes are adsorption, chelation and ion exchange. The slow stage is different for each species and metal. Cr precipitation induced by roots occurs in P. stratiotes. Cr uptake through leaves is probably the main cause of the increase of Cr in the aerial parts of S. herzogii. - Cd uptake processes are biological processes in S. herzogii and adsorption, chelation and ionic exchange are in P. stratiotes, whereas Cr uptake processes in both macrophytes are adsorption, chelation and ion exchange

Application of in-situ bioassays with macrophytes in aquatic mesocosm studies.

Science.gov (United States)

Coors, Anja; Kuckelkorn, Jochen; Hammers-Wirtz, Monika; Strauss, Tido

2006-10-01

Aquatic mesocosm studies assess ecotoxicological effects of chemicals by using small artificial ponds as models of lentic ecosystems. In this study, methods of controlled insertion of macrophytes within an outdoor mesocosm study were explored. Although analytically confirmed concentrations of the model herbicide terbuthylazine were high enough to expect direct effects on phytoplankton, functional parameters and dominant taxa abundance indicated only minor and transient effects. In-situ assays with Lemna minor, Myriophyllum spicatum, Potamogeton lucens and Chara globularis revealed adverse effects at concentrations in accordance with literature data. Complex interactions such as nutrient limitation and competition were possible reasons for the observed growth promotion at the lower concentration of about 5 microg/l terbuthylazine. The approach of macrophyte in-situ bioassays within a mesocosm study proved to be applicable. Presumed advantages are simultaneous acquisition of toxicity data for several species of aquatic plants under more realistic conditions compared to laboratory tests and inclusion of macrophytes as important structural and functional components in mesocosms while limiting their domination of the model ecosystem.

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.

Quantification of the impact of macrophytes on oxygen dynamics and nitrogen retention in a vegetated lowland river

Science.gov (United States)

Desmet, N. J. S.; Van Belleghem, S.; Seuntjens, P.; Bouma, T. J.; Buis, K.; Meire, P.

When macrophytes are growing in the river, the vegetation induces substantial changes to the water quality. Some effects are the result of direct interactions, such as photosynthetic activity or nutrient uptake, whereas others may be attributed to indirect effects of the water plants on hydrodynamics and river processes. This research focused on the direct effect of macrophytes on oxygen dynamics and nutrient cycling. Discharge, macrophyte biomass density, basic water quality, dissolved oxygen and nutrient concentrations were in situ monitored throughout the year in a lowland river (Nete catchment, Belgium). In addition, various processes were investigated in more detail in multiple ex situ experiments. The field and aquaria measurement results clearly demonstrated that aquatic plants can exert considerable impact on dissolved oxygen dynamics in a lowland river. When the river was dominated by macrophytes, dissolved oxygen concentrations varied from 5 to 10 mg l -1. Considering nutrient retention, it was shown that the investigated in-stream macrophytes could take up dissolved inorganic nitrogen (DIN) from the water column at rates of 33-50 mg N kgdry matter-1 h. And DIN fluxes towards the vegetation were found to vary from 0.03 to 0.19 g N ha -1 h -1 in spring and summer. Compared to the measured changes in DIN load over the river stretch, it means that about 3-13% of the DIN retention could be attributed to direct nitrogen uptake from the water by macrophytes. Yet, the role of macrophytes in rivers should not be underrated as aquatic vegetation also exerts considerable indirect effects that may have a greater impact than the direct fixation of nutrients into the plant biomass.

Note - Des macrophytes pour épurer les eaux ?

Directory of Open Access Journals (Sweden)

BOUTIN, Catherine

2014-12-01

Full Text Available Utiliser des macrophytes pour mieux satisfaire les besoins humains est une part importante des recherches qui les concernent. Pour l’épuration des eaux usées et les aménagements associés, qu’en est-il ?

African Journal of Science and Technology (AJST) MACROPHYTES ...

African Journals Online (AJOL)

opiyo

incidence des macrophytes aquatiques et du plancton sur la qualité des eaux du lac de Guiers», financé par la région Wallonne de Belgique avec l'appui de la. Fondation Universitaire Luxembourgeoise (Arlon). Nous les remercions pour leur concours.

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

Science.gov (United States)

Knauert, Stefanie; Singer, Heinz; Hollender, Juliane; Knauer, Katja

2010-01-01

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.

Trophic structure of the fouling community in Odessa Bay (Black Sea

Directory of Open Access Journals (Sweden)

A. Y. Varigin

2016-06-01

Full Text Available The trophic structure of the coastal fouling community of Odessa Bay (Black Sea, which was composed of 10 species of macrophytes, 57 invertebrate species and 4 species of fish, was determined. The basic trophic relationship between organisms composing the community is shown. A minimization of interspecific trophic competition within the community is noted. The main sources of food material entering the fouling community were determined. We show that a significant proportion of food in the form of detritus, dissolved organic matter and small planktonic organisms enters the community from the water column. Filtration and pumping activity of sestonophage-organisms, particularly mussels, helps to attract food material to the community. Primary producers of the community are macrophytes and microphytes, which develop on account of their photosynthetic activity and ensure the provision of food to herbivores. The trophic group of detritophages consumes different fractions of the detritus which accumulates in the byssus threads of bivalve molluscs. In this context, mussel druses act as sediment traps, collecting detritus. Numerous polyphages, which are essentially omnivores and do not usually lack food material, were noted in the community. A small group of carnivorous invertebrates, whose representatives actively attack small animals, was identified. The abundance of these species in the community was about 1%, and their biomass less than 0.6%. Fish living in macrophyte weeds are the consumers in the community. We determined that the highest relative abundance (over 36% in the fouling community was reached by sestonophages and polyphages. We found that the undisputed leader in the relative biomass (over 97% in the fouling community ofOdessaBaywas the sestonophages (mainly composed of mussels. We determined that the trophic structure index of the community was 0.94, which confirms the significant dominance in biomass of bivalves over other species in

Application of macrophytes as biosorbents for radioactive liquid waste treatment

International Nuclear Information System (INIS)

Vieira, Ludmila Cabreira

2016-01-01

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)

Spectral discrimination of macrophyte species during different seasons in a tropical wetland using in-situ hyperspectral remote sensing

Science.gov (United States)

Saluja, Ridhi; Garg, J. K.

2017-10-01

Wetlands, one of the most productive ecosystems on Earth, perform myriad ecological functions and provide a host of ecological services. Despite their ecological and economic values, wetlands have experienced significant degradation during the last century and the trend continues. Hyperspectral sensors provide opportunities to map and monitor macrophyte species within wetlands for their management and conservation. In this study, an attempt has been made to evaluate the potential of narrowband spectroradiometer data in discriminating wetland macrophytes during different seasons. main objectives of the research were (1) to determine whether macrophyte species could be discriminated based on in-situ hyperspectral reflectance collected over different seasons and at each measured waveband (400-950nm), (2) to compare the effectiveness of spectral reflectance and spectral indices in discriminating macrophyte species, and (3) to identify spectral wavelengths that are most sensitive in discriminating macrophyte species. Spectral characteristics of dominant wetland macrophyte species were collected seasonally using SVC GER 1500 portable spectroradiometer over the 400 to 1050nm spectral range at 1.5nm interval, at the Bhindawas wetland in the state of Haryana, India. Hyperspectral observations were pre-processed and subjected to statistical analysis, which involved a two-step approach including feature selection (ANOVA and KW test) and feature extraction (LDA and PCA). Statistical analysis revealed that the most influential wavelengths for discrimination were distributed along the spectral profile from visible to the near-infrared regions. The results suggest that hyperspectral data can be used discriminate wetland macrophyte species working as an effective tool for advanced mapping and monitoring of wetlands.

Reaeration of oxygen in shallow, macrophyte rich streams. 1

International Nuclear Information System (INIS)

Thyssen, N.; Erlandsen, M.; Jeppesen, E.

1987-01-01

The rate coefficient K 2 for the exchange of oxygen between flowing water and the atmosphere (reaeration) has been studied in six Danish streams covering a relatively wide range of hydraulic conditions, pollutional loading, and macrophyte abundance. 103 K 2 measurements were performed in 1978-85. 82 measurements were obtained applying 5 different indirect methods all balancing the sources and sinks of stream dissolved oxygen under conditions of normal operation of the system (3 methods) and under artificial depletion of the oxygen concentration of the stream water by addition of sodium sulfite (2 methods). 21 K 2 values were determined directly applying the gaseous tracer 85 Kr for reaeration. Guidelines for selecting a proper method to determine K 2 knowing macrophyte biomass and loading characteristics of the particular stream are provided. (author)

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

Different response of phytochelatins in two aquatic macrophytes ...

African Journals Online (AJOL)

Phytochelatins (PCs) have been proposed as potential biomarkers for an evaluation of metal toxicity. However, most studies have been generally limited to high concentrations of metals. In this study, two submerged macrophytes Ceratophyllum demersum L. and Elodea canadensis Michx. were adopted to investigate the ...

Levels and distribution of cobalt and nickel in the aquatic macrophytes found in Skadar Lake, Montenegro.

Science.gov (United States)

Kastratović, Vlatko; Bigović, Miljan; Jaćimović, Željko; Kosović, Milica; Đurović, Dijana; Krivokapić, Slađana

2018-02-06

Macrophytes react to changes in the quality of the environment in which they live (water/sediment), and they are good bioindicators of surface water conditions. In the present study, the content of the metals cobalt (Co) and nickel (Ni) was determined in the sediment, the water, and different organs of macrophytes from six localities around Lake Skadar, across four different seasons of year. The aquatic macrophytes that have been used as bioindicator species in this study are Phragmites australis (an emerged species), Ceratophyllum demersum (a submerged species), and Lemna minor (a floating species). The aim of this study was to determine the distribution of metals in macrophyte tissues and also to discover the degree of bioaccumulation of the investigated metals, depending both on the location and on the season. The content of Co and Ni in the examined parts of the macrophytes was in the range of 0.04-8.78 and 0.30-28.5 ppm, respectively. The greatest content of the investigated metal in the organs of P. australis and C. demersum was recorded at the beginning of and during the growing season. Greater concentrations of metals in the tissue of L. minor were observed at the end of the growing season.

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.

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

International Nuclear Information System (INIS)

Vervliet-Scheebaum, Marco; Straus, Alain; Tremp, Horst; Hamer, Mick; Maund, Stephen J.; Wagner, Edgar; Schulz, Ralf

2010-01-01

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.

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.

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

Science.gov (United States)

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

2004-03-01

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 eutrophic ecosystems with a high Lemna surface coverage (Lemna). This paper describes the fate of the chemicals as well as their effects on the growth of Myriophyllum spicatum and the periphytic algal community. In the Elodea-dominated microcosms significant increase in the biomass and alterations of species composition of the periphytic algae were observed, but no effect on M. spicatum growth could be recorded in response to the treatment. The opposite was found in the Lemna-dominated microcosms, in which decreased growth of M. spicatum was observed but no alterations could be found in the periphytic community. In the Elodea-dominated microcosms the species composition of the periphytic algae diverged from that of the control following treatment with 0.5% spray drift emission of the label-recommended rate (5% for lambda-cyhalothrin), while reduced growth of M. spicatum in the Lemna-dominated microcosms was recorded at 2% drift (20% for lambda-cyhalothrin). This study shows that the structure of the ecosystem influences the final effect of pesticide exposure.

Bisphenol A Removal by Submerged Macrophytes and the Contribution of Epiphytic Microorganisms to the Removal Process.

Science.gov (United States)

Zhang, Guosen; Wang, Yu; Jiang, Jinhui; Yang, Shao

2017-06-01

Bisphenol A (BPA), a typical endocrine disruptor, has been found in global aquatic environments, causing great concern. The capabilities of five common submerged macrophytes to remove BPA from water and the contributions of epiphytic microorganisms were investigated. Macrophytes removed 62%-100% of total BPA (5 mg/L) over 12 days; much higher rates than that observed in the control (2%, F = 261.511, p = 0.000). Ceratophyllum demersum was the most efficient species. C. demersum samples from lakes with different water qualities showed no significant differences in BPA removal rates. Moreover, removal, inhibition or re-colonization of epiphytic microorganisms did not significantly change the BPA removal rates of C. demersum. Therefore, the contributions of epiphytic microorganisms to the BPA removal process were negligible. The rate of BPA accumulation in C. demersum was 0.1%, indicating that BPA was mainly biodegraded by the macrophyte. Hence, submerged macrophytes, rather than epiphytic microorganisms, substantially contribute to the biodegradation of BPA in water.

Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies - Effects of macrophytes

DEFF Research Database (Denmark)

Chen, Xijuan; Pauly, Udo; Rehfus, Stefan

2009-01-01

as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted...... into containers (lysimeters) with a size of 1 m × 1 m × 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under...... environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years...

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., ...

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

Biological control of phytoplankton by the subtropical submerged macrophytes Egeria densa and Potamogeton illinoensis: a mesocosm study

NARCIS (Netherlands)

Vanderstukken, M.; Mazzeo, N.; Colen, W.; Declerck, S.A.J.; Muylaert, K.

2011-01-01

1. In temperate regions, submerged macrophytes can hamper phytoplankton blooms. Such an effect could arise directly, for instance via allelopathy, or indirectly, via competition for nutrients or the positive interaction between submerged macrophytes and zooplankton grazing. However, there is some

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.

Elemental gradients in macrophytes from a reactor effluent gradient

International Nuclear Information System (INIS)

Grace, J.B.; Tilly, L.J.

1978-01-01

The tissues of submersed macrophtes from along the thermal gradient were analyzed for phosphorus to determine whether any pattern correspondent to standing crop distributions could be detected. Although water concentrations of phosphorus showed no detectable relationship to the thermal effluent, tissue concentrations of this element in submersed macrophytes declined with distance from the effluent entry point. The occurrence of this concentration pattern suggests that phosphorus availability is greater near the discharge. Because phosphorus is the element most often determined to limit aquatic productivity, its greater availability may partially account for the apparent enhancement of macrophte growth near the thermal discharge. A patter of macrophyte abundance which indicated enchancement related to the discharge gradient in the reactor-cooling reservoir, Par Pond is reported. Correlative data tended to implicate light and temperature as important in influencing the differential abundance pattern

Macrophytes and periphyton carbon subsidies to bacterioplankton and zooplankton in a shallow eutrophic lake in tropical China

NARCIS (Netherlands)

de Kluijver, A.; Ning, J.; Liu, Z.; Jeppesen, E.; Gulati, R.D.; Middelburg, J.J.

The subsidy of carbon derived from macrophytes and associated periphyton to bacterioplankton and zooplankton in subtropical shallow eutrophic Huizhou West Lake in China was analyzed using carbon stable isotope signatures. A restored part of the lake dominated by macrophytes was compared with an

Macrophytes and periphyton carbon subsidies to bacterioplankton and zooplankton in a shallow eutrophic lake in tropical China

NARCIS (Netherlands)

de Kluijver, A.; Ning, J.; Liu, Z.; Jeppesen, E.; Gulati, R.D.; Middelburg, J.J.

2015-01-01

The subsidy of carbon derived from macrophytes and associated periphyton to bacterioplankton and zooplankton in subtropical shallow eutrophic Huizhou West Lake in China was analyzed using carbon stable isotope signatures. A restored part of the lake dominated by macrophytes was compared with an

Macrophyte growth module for the SWAT model – impact of climate change and management on stream ecology

DEFF Research Database (Denmark)

Lu, Shenglan; Trolle, Dennis; Erfurt, Jytte

To access how multiple stressors affect the water quantity and quality and stream ecology at catchment scale under various management and climate change scenarios, we implemented macrophyte growth modules for the Soil and Water Assessment Tool version 2012 (SWAT). The macrophyte growth module...

SUBMERGED MACROPHYTE EFFECTS ON NUTRIENT EXCHANGES IN RIVERINE SEDIMENTS

Science.gov (United States)

Submersed macrophytes are important in nutrient cycling in marine and lacustrine systems, although their role in nutrient exchange in tidally-influenced riverine systems is not well studied. In the laboratory, plants significantly lowered porewater nutrient pools of riverine sedi...

The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

Science.gov (United States)

Bulla, C. K.; Gomes, Luiz Carlos; Miranda, Leandro E.; Agostinho, A. A.

2011-01-01

We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.

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

We examined the relationship between environmental factors and the richness of submerged macrophytes species in 73 Danish lakes, which are mainly small, shallow, and have mesotrophic to hypertrophic conditions. We found that mean species richness per lake was only 4.5 in acid lakes of low...... alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... 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...

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

Directory of Open Access Journals (Sweden)

Beatriz MODENUTTI

2011-08-01

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

Detection of Copper (II) and Cadmium (II) binding to dissolved organic matter from macrophyte decomposition by fluorescence excitation-emission matrix spectra combined with parallel factor analysis

International Nuclear Information System (INIS)

Yuan, Dong-hai; Guo, Xu-jing; Wen, Li; He, Lian-sheng; Wang, Jing-gang; Li, Jun-qi

2015-01-01

Fluorescence excitation-emission matrix (EEM) spectra coupled with parallel factor analysis (PARAFAC) was used to characterize dissolved organic matter (DOM) derived from macrophyte decomposition, and to study its complexation with Cu (II) and Cd (II). Both the protein-like and the humic-like components showed a marked quenching effect by Cu (II). Negligible quenching effects were found for Cd (II) by components 1, 5 and 6. The stability constants and the fraction of the binding fluorophores for humic-like components and Cu (II) can be influenced by macrophyte decomposition of various weight gradients in aquatic plants. Macrophyte decomposition within the scope of the appropriate aquatic phytomass can maximize the stability constant of DOM-metal complexes. A large amount of organic matter was introduced into the aquatic environment by macrophyte decomposition, suggesting that the potential risk of DOM as a carrier of heavy metal contamination in macrophytic lakes should not be ignored. - Highlights: • Macrophyte decomposition increases fluorescent DOM components in the upper sediment. • Protein-like components are quenched or enhanced by adding Cu (II) and Cd (II). • Macrophyte decomposition DOM can impact the affinity of Cu (II) and Cd (II). • The log K M and f values showed a marked change due to macrophyte decomposition. • Macrophyte decomposition can maximize the stability constant of DOM-Cu (II) complexes. - Macrophyte decomposition DOM can influence on the binding affinity of metal ions in macrophytic lakes

Effects of the herbicide metazachlor on macrophytes and ecosystem function in freshwater pond and stream mesocosms.

Science.gov (United States)

Mohr, S; Berghahn, R; Feibicke, M; Meinecke, S; Ottenströer, T; Schmiedling, I; Schmiediche, R; Schmidt, R

2007-05-01

The chloroacetamide metazachlor is a commonly used pre-emergent herbicide to inhibit growth of plants especially in rape culture. It occurs in surface and ground water due to spray-drift or run-off in concentrations up to 100 microgL(-1). Direct and indirect effects of metazachlor on aquatic macrophytes were investigated at oligo- to mesotrophic nutrient levels employing eight stream and eight pond indoor mesocosms. Five systems of each type were dosed once with 5, 20, 80, 200 and 500 microgL(-1) metazachlor and three ponds and three streams served as controls. Pronounced direct negative effects on macrophyte biomass of Potamogeton natans, Myriophyllum verticillatum and filamentous green algae as well as associated changes in water chemistry were detected in the course of the summer 2003 in both pond and stream mesocosms. Filamentous green algae dominated by Cladophora glomerata were the most sensitive organisms in both pond and stream systems with EC(50) ranging from 3 (streams) to 9 (ponds) microgL(-1) metazachlor. In the contaminated pond mesocosms with high toxicant concentrations (200 and 500 microgL(-1)), a species shift from filamentous green algae to the yellow-green alga Vaucheria spec. was detected. The herbicide effects for the different macrophyte species were partly masked by interspecific competition. No recovery of macrophytes was observed at the highest metazachlor concentrations in both pond and stream mesocosms until the end of the study after 140 and 170 days. Based on the lowest EC(50) value of 4 microgL(-1) for total macrophyte biomass, it is argued that single exposure of aquatic macrophytes to metazachlor to nominal concentrations >5 microgL(-1) is likely to have pronounced long-term effects on aquatic biota and ecosystem function.

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.

Can aquatic macrophytes be biofilters for gadolinium based contrasting agents?

Science.gov (United States)

Braun, Mihály; Zavanyi, Györgyi; Laczovics, Attila; Berényi, Ervin; Szabó, Sándor

2018-05-15

The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue concentration of Gd reached its maximum value between day one and four in L. gibba and C. demersum, respectively, and its volume was significantly higher in C. demersum than in L. gibba. In C. demersum, the open-chain ligand Omniscan causes two-times higher tissue Gd concentration than the macrocyclic ligand Dotarem. Gadolinium was released from Gd-treated duckweeds into the water as they were grown further in Gd-free nutrient solution. Tissue Gd concentration dropped by 50% in duckweed treated by Omniscan and by Dotarem within 1.9 and 2.9 days respectively. None of the macrophytes had a significant impact on the Gd concentration of water in low and medium concentration levels (1-256 μg L -1 ). Biofiltration of GBCA-s by common macrophytes could not be detected in our experiments. Therefore it seems that in constructed wetlands, aquatic plants are not able to reduce the concentration of GBCA-s in the water. Furthermore there is a low risk that these plants cause the

Biomechanical tactics of chiral growth in emergent aquatic macrophytes

Science.gov (United States)

Zhao, Zi-Long; Zhao, Hong-Ping; Li, Bing-Wei; Nie, Ben-Dian; Feng, Xi-Qiao; Gao, Huajian

2015-01-01

Through natural selection, many plant organs have evolved optimal morphologies at different length scales. However, the biomechanical strategies for different plant species to optimize their organ structures remain unclear. Here, we investigate several species of aquatic macrophytes living in the same natural environment but adopting distinctly different twisting chiral morphologies. To reveal the principle of chiral growth in these plants, we performed systematic observations and measurements of morphologies, multiscale structures, and mechanical properties of their slender emergent stalks or leaves. Theoretical modeling of pre-twisted beams in bending and buckling indicates that the different growth tactics of the plants can be strongly correlated with their biomechanical functions. It is shown that the twisting chirality of aquatic macrophytes can significantly improve their survivability against failure under both internal and external loads. The theoretical predictions for different chiral configurations are in excellent agreement with experimental measurements. PMID:26219724

Bacterial growth on macrophyte leachate and fate of bacterial production

International Nuclear Information System (INIS)

Findlay, S.; Carlough, L.; Crocker, M.T.; Gill, H.K.; Meyer, J.L.; Smith, P.J.

1986-01-01

The role bacteria play in transferring organic carbon to other trophic levels in aquatic ecosystems depends on the efficiency with which they convert dissolved organic [ 14 C]-labelled carbon into bacterial biomass and on the ability of consumers to graze bacteria. The authors have measured the conversion efficiency for bacteria growing on macrophyte-derived dissolved organic carbon and estimated the amount of bacterial production removed by grazing. Bacteria converted this DOC into new tissue with an efficiency of 53%, substantially higher than the apparent conversion efficiency of macrophyte-derived particulate organic carbon or other types of DOC. Two estimates of grazing indicate that the decline in bacterial numbers after the bloom was probably due to grazing by flagellates. These results show the significance of the bacterial link between DOC and other trophic levels

Salinity and pH effects on floating and emergent macrophytes in a constructed wetland.

Science.gov (United States)

Hadad, H R; Mufarrege, M M; Di Luca, G A; Maine, M A

2017-04-01

Salvinia herzogii, Pistia stratiotes and Eichhornia crassipes (floating species) were the dominant macrophytes in a constructed wetland (CW) over the first years of operation. Later, the emergent Typha domingensis displaced the floating species, becoming dominant. The industrial effluent treated at this CW showed high pH and salinity. The aim of this work was to study the tolerance of floating species and T. domingensis exposed to different pH and salinity treatments. Treatments at pH 8, 9, 10 and 11 and salinities of 2,000; 3,000; 4,000; 6,000; and 8,000 mg L -1 were performed. Floating macrophytes were unable to tolerate the studied pH and salinity ranges, while T. domingensis tolerated higher pH and salinity values. Many industrial effluents commonly show high pH and salinity. T. domingensis demonstrated to be a suitable macrophyte to treat this type of effluents.

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

International Nuclear Information System (INIS)

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

2010-01-01

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 (2.97 mg L -1 ), GA (2.65 mg L -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% (P < 0.05), respectively, after 24-h exposure, but no inhibition effect was found in S. capricornutum. The dark respiration and photosystem I (PSI) activities of M. aeruginosa were significantly increased by exposure to PA and GA (P < 0.05). Nevertheless, EA and CA had no influence on the electron 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

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

Energy Technology Data Exchange (ETDEWEB)

Zhu Junying [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu Biyun [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 (China); Wang Jing; Gao Yunni [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Wu Zhenbin, E-mail: wuzb@ihb.ac.cn [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072 (China)

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 (2.97 mg L{sup -1}), GA (2.65 mg L{sup -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% (P < 0.05), respectively, after 24-h exposure, but no inhibition effect was found in S. capricornutum. The dark respiration and photosystem I (PSI) activities of M. aeruginosa were significantly increased by exposure to PA and GA (P < 0.05). Nevertheless, EA and CA had no influence on the electron 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

Bimodality in stable isotope composition facilitates the tracing of carbon transfer from macrophytes to higher trophic levels

NARCIS (Netherlands)

Mendonca, R.; Kosten, S.; Lacerot, G.; Mazzeo, N.; Roland, F.; Ometto, J.P.; Paz, A.; Bueno, O.C.; Gomes, A.C.M.M.; Scheffer, M.

2013-01-01

Even though the suitability of macrophytes to act as a carbon source to food webs has been questioned by some studies, some others indicate that macrophyte-derived carbon may play an important role in the trophic transfer of organic matter in the food web of shallow lakes. To evaluate the importance

Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake.

Science.gov (United States)

Attermeyer, K; Flury, S; Jayakumar, R; Fiener, P; Steger, K; Arya, V; Wilken, F; van Geldern, R; Premke, K

2016-02-05

Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km(2)) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets.

Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake

Science.gov (United States)

Attermeyer, K.; Flury, S.; Jayakumar, R.; Fiener, P.; Steger, K.; Arya, V.; Wilken, F.; van Geldern, R.; Premke, K.

2016-02-01

Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km2) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets.

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.

[Isolation, Purification and Identification of Antialgal Activity Substances of Ethyl Acetate Extracts from the Submerged Macrophytes Potamogeton crispus].

Science.gov (United States)

Sun, Ying-ying; Su, Zhen-xia; Pu, Yin-fang; Xiao, Hui; Wang, Chang-hai

2015-10-01

Previous studies showed that ethyl acetate extracts from the submerged macrophytes Potamogeton crispus can significantly inhibit the growth of Karenia mikimitoi. Further, two antialgal activity compounds (1-2) were successfully isolated from this submerged macrophytes through a combination of silica gel column chromagraphy and repeated preparative thin-layer chromatography in this paper. These two antialgal activity compounds exhibited antialgal active against Karenia mikimitoi. Furthermore, their structure were identified on the basis of spectroscopic data: one flavonid named Trichodermatides B, and one alkaloid named 2-methylheptylisonicotinate. These two compounds were for the first time isolated from both Potamogeton crispus and submerged macrophytes.

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.

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

Répartition et valorisation des macrophytes envahissantes dans la ...

African Journals Online (AJOL)

... of Littoral (Cameroon) threatened by invasive macrophytes, an ecological study highlighting the ... The floristic inventory showed that 2 species (Eichhornia crassipes and Panicum ... This plant can thus be used for biogas or compost production ... Tanzania (19); Togo (1); Tunisia (2); Uganda (12); Zambia (2); Zimbabwe (12).

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.  

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.

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.

Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir

Directory of Open Access Journals (Sweden)

M. B. Cunha-Santino

Full Text Available Abstract Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL, the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species, Pontederiaceae (3 species and Onarograceae (3 genera were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell. Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw. Kunth, Eleocharis sp1, Eichhornia crassipes (Mart. Solms, Oxycaryum cubense (Poepp. & Kunth Lye always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%, followed by submersed rooted (24.5%, free floating (19.5%, floating rooted (9.7% and free submersed (0.3%. Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among

Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir.

Science.gov (United States)

Cunha-Santino, M B; Fushita, A T; Peret, A C; Bianchini-Junior, I

2016-05-03

Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at describing and comparing the incidence of aquatic macrophytes in a throughflowing, non-dendritic tropical reservoir. During February 2006 to November 2007, eight limnological surveys were performed quarterly within the Ourinhos Reservoir, and in the mouth areas of its tributaries. At the six sampling stations 30 variables were measured. The number of sites with plants varied between 21 and 38 and at the end of the 1st year the total richness was found. The sampling survey outcome the recognition of 18 species of aquatic macrophytes; Cyperaceae (2 genera and 1 species), Pontederiaceae (3 species) and Onarograceae (3 genera) were the families with higher diversity. Seven species (Typha domingensis Pers., Myriophyllum aquaticum (Vell.) Verdec, Salvinia auriculata Aubl., Eichhornia azurea (Sw.) Kunth, Eleocharis sp1, Eichhornia crassipes (Mart.) Solms, Oxycaryum cubense (Poepp. & Kunth) Lye) always were present and were more frequent in the sites. The occurrence of emergent species predominated (45.9%), followed by submersed rooted (24.5%), free floating (19.5%), floating rooted (9.7%) and free submersed (0.3%). Although limnological variables and the distribution of macrophytes have discriminated the same sampling points, the stepwise multiple linear regressions did not pointed out strong correspondences (or coherence) among the most constant and distributed macrophyte species and the selected limnological variables, as well the trophic statuses. Seeing the low relationship among limnological

Experimental evidence for enhanced top-down control of freshwater macrophytes with nutrient enrichment.

Science.gov (United States)

Bakker, Elisabeth S; Nolet, Bart A

2014-11-01

The abundance of primary producers is controlled by bottom-up and top-down forces. Despite the fact that there is consensus that the abundance of freshwater macrophytes is strongly influenced by the availability of resources for plant growth, the importance of top-down control by vertebrate consumers is debated, because field studies yield contrasting results. We hypothesized that these bottom-up and top-down forces may interact, and that consumer impact on macrophyte abundance depends on the nutrient status of the water body. To test this hypothesis, experimental ponds with submerged vegetation containing a mixture of species were subjected to a fertilization treatment and we introduced consumers (mallard ducks, for 8 days) on half of the ponds in a full factorial design. Over the whole 66-day experiment fertilized ponds became dominated by Elodea nuttallii and ponds without extra nutrients by Chara globularis. Nutrient addition significantly increased plant N and P concentrations. There was a strong interactive effect of duck presence and pond nutrient status: macrophyte biomass was reduced (by 50%) after the presence of the ducks on fertilized ponds, but not in the unfertilized ponds. We conclude that nutrient availability interacts with top-down control of submerged vegetation. This may be explained by higher plant palatability at higher nutrient levels, either by a higher plant nutrient concentration or by a shift towards dominance of more palatable plant species, resulting in higher consumer pressure. Including nutrient availability may offer a framework to explain part of the contrasting field observations of consumer control of macrophyte abundance.

The distribution of radionuclides between the sediments and macrophytes in the cooling pond of the Ignalina NPP - The Distribution of Radionuclides in Freshwater Hydro Ecosystem's Bottom Sediments and Macrophytes depending on the Ecological Conditions

International Nuclear Information System (INIS)

Marciulioniene, D.; Jefanova, O.; Mazeika, J.

2014-01-01

The distribution of 137 Cs, 60 Co, 54 Mn in the aquatory of lake Drukshiai (the monitoring stations), the coastal area of this lake, the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP was analyzed on the basis of long-term (1988-2009) investigations of radionuclides specific activity in bottom sediments and macrophytes, also the ability of radionuclides falling into lake Drukshiai from the Ignalina NPP through effluents channels was assessed. It was established that 137 Cs, 60 Co and 54 Mn in the bottom sediments and the macrophytes were distributed quite differently in the monitoring stations of lake Drukshiai and the coastal area as well as in the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP. The different characteristics of the sediments, various ecological conditions, as well as the existing anthropogenic environmental factors and the different in the ecological groups of the plants could have had impact on the distribution of 137 Cs, 60 Co and 54 Mn in the bottom sediments and the aquatic plants in lake Drukshiai and the effluents channels of the Ignalina NPP. The 137 Cs, 60 Co and 54 Mn specific activity's values were significantly higher in macrophytes from the industrial drainage systems channel of Ignalina NPP than in macrophytes from the cooling water channel. Nevertheless the specific activities level of these radionuclides differed only slightly in the macrophytes from the areas which were impacted by the effluents channels of the Ignalina NPP. This can be explained by the fact that the phyto-remediation (as the form of auto-purification) of these effluents from the radionuclides had been present in the industrial drainage systems channel of Ignalina NPP before entering the water into lake Drukshiai. (authors)

In situ experiments to determine the uptake of copper by the aquatic macrophyte Najas tenuifolia R.Br

International Nuclear Information System (INIS)

Hart, B.T.; Jones, M.J.; Breen, P.

1984-01-01

In situ experiments, in which ionic copper was added to an enclosed area of the aquatic macrophyte Najas tenuifolia R.Br., showed that this plant can rapidly (in around six hours) take up considerable amounts of the added copper. Epiphytes (and their associated microfauna) present on this macrophyte took up the added copper even more rapidly, but also seemed to release the copper equally fast. At the end of the three day experiment 30% to 60% of the added copper was associated with the macrophytes and 15% to 20% was still in the water column. The remainder of the copper was associated with the 'epiphyte component', the sediments and probably also the walls of the plastic enclosure

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 ...

Environmental study of some metals on several aquatic macrophytes

African Journals Online (AJOL)

Administrator

2011-09-26

Sep 26, 2011 ... Concentration of Fe, Mn, Cu and Pb (mgkg-1 dry weight) in leaves, stems and roots of five macrophytes (BTS = Bidens tripartitus - stem, BTL = Bidens tripartitus – leaf, PAS = Polygonum amphibium - stem, PAL = Polygonum amphibium – leaf, LES = Lycopus europaeus - stem, LEL = Lycopus europaeus ...

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 (pVenice, macrophytes, lipid peroxidation.

AMEG: the new SETAC advisory group on auqatic macrophyte ecotoxicology

NARCIS (Netherlands)

Arts, G.H.P.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M.A.

2010-01-01

ntroduction 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

Exocellular electron transfer in anaerobic microbial communities.

Science.gov (United States)

Stams, Alfons J M; de Bok, Frank A M; Plugge, Caroline M; van Eekert, Miriam H A; Dolfing, Jan; Schraa, Gosse

2006-03-01

Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory syntrophic consortia of proton-reducing acetogenic bacteria and hydrogen-consuming methanogenic archaea. Anaerobic microorganisms that use insoluble electron acceptors for growth, such as iron- and manganese-oxide as well as inert graphite electrodes in microbial fuel cells, also transfer electrons exocellularly. Soluble compounds, like humic substances, quinones, phenazines and riboflavin, can function as exocellular electron mediators enhancing this type of anaerobic respiration. However, direct electron transfer by cell-cell contact is important as well. This review addresses the mechanisms of exocellular electron transfer in anaerobic microbial communities. There are fundamental differences but also similarities between electron transfer to another microorganism or to an insoluble electron acceptor. The physical separation of the electron donor and electron acceptor metabolism allows energy conservation in compounds as methane and hydrogen or as electricity. Furthermore, this separation is essential in the donation or acceptance of electrons in some environmental technological processes, e.g. soil remediation, wastewater purification and corrosion.

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 ...

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.

Effects of four fungicides on nine non-target submersed macrophytes

NARCIS (Netherlands)

Belgers, J.D.M.; Aalderink, G.H.; Brink, van den P.J.

2009-01-01

We tested the sensitivity of nine submersed macrophyte species to the fungicides chlorothalonil, pentachlorophenol, fluazinam, and carbendazim. Endpoints determined 3 weeks after the start of the treatment were based on shoot and root growth in water. Carbendazim proved not or only moderately toxic

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.

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

Energy Technology Data Exchange (ETDEWEB)

Lewander, M.

1995-06-01

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

Differential photosynthetic and morphological adaptations to low light affect depth distribution of two submersed macrophytes in lakes.

Science.gov (United States)

Chen, Jianfeng; Cao, Te; Zhang, Xiaolin; Xi, Yilong; Ni, Leyi; Jeppesen, Erik

2016-10-03

To evaluate the relative importance of photosynthetic versus morphological adaptations of submersed macrophytes to low light intensity in lakes, rapid light curves (RLCs), morphological parameters, relative growth rate (RGR), clonal reproduction and abundance of two submersed macrophytes (Potamogeton maackianus and Vallisneria natans) were examined under 2.8%, 7.1%, 17.1% and 39.5% ambient light in a field and outdoor experimental study. The plants increased their initial slope of RLCs (α) and decreased their minimum saturating irradiance (E k ) and maximum relative electron transport rate (ETRm) of RLCs under low light stress, but V. natans was more sensitive in RLCs than P. maackianus. Accordingly, the RGR, plant height and abundance of P. maackianus were higher in the high light regimes (shallow water) but lower in the low light regimes than those of V. natans. At the 2.8% ambient light, V. natans produced ramets and thus fulfilled its population expansion, in contrast to P. maackianus. The results revealed that P. maackianus as a canopy-former mainly elongated its shoot length towards the water surface to compensate for the low light conditions, however, it became limited in severe low light stress conditions. V. natans as a rosette adapted to low light stress mainly through photosynthetic adjustments and superior to severely low light than shoot elongation.

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

Chemical warfare in freshwater, allelopathic 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

[The distribution of artificial radionuclides in the biomass of macrophytes of the Yenisei River].

Science.gov (United States)

Zotina, T A

2009-01-01

The Yenisei River is contaminated with artificial radionuclides due to the operation of the Mining-and-Chemical Combine (MCC), Rosatom, producing weapon grade plutonium for several decades. Artificial radionuclides including activation isotopes and transuranics, are detected in the biomass of submerged aquatic plants of the river. We investigated the distribution of artificial radionuclides in the biomass of macrophytes from radioactively contaminated part of the Yenisei River with chemical fractionation techniques. Artificial radionuclides were detected in extracellular and intracellular compartments of the macrophytes. The distribution of radionuclides among the biomass fractions differed essentially. 54Mn was preferably in mobile, exchangeable form compared to other isotopes. Essential portion of 137Cs was in non exchangeable form. Significant activity of artificial radionuclides was detected in the particles of suspended matter of the river, attached to the plant surfaces. Radioactive isotopes were distributed among biomass fractions similar to stable isotopes. The distribution of potassium and 137Cs differed essentially. On the basis of the results obtained the assumptions on the further migration of radionuclides accumulated by aquatic macrophytes in the Yenisei River have been done.

Forecasting the impact of an invasive macrophyte species in the littoral zone through aquatic insect species composition

Directory of Open Access Journals (Sweden)

Hugo H. L. Saulino

2017-11-01

Full Text Available ABSTRACT Invasive macrophytes threaten freshwater ecosystem biodiversity. We analyzed the impact of the invasive white ginger lily (Hedychium coronarium J. König, Zingiberaceae on aquatic insect assemblages living in the littoral zone of a tropical reservoir. We took aquatic insect samples in the littoral zone on four main vegetal profile banks: white ginger monotypic bank, forest partially invaded, native macrophyte monotypic bank and riparian forest. At each vegetal bank, we measured abiotic variables such as dissolved oxygen, pH, water temperature and depth. We analyzed the aquatic insects through abundance, richness and Simpson diversity. We used the non-Metric Multidimensional Scaling (nMDS analysis to analyze the spatial distribution of each assemblage, and Analysis of similarities (ANOSIM to verify differences amongst dissimilarity distances. Additionally, we analyzed the main taxa associated with invasive macrophytes through indicator species analyses using IndVal index. We observed that the invasive macrophyte banks presented higher abundance of associated specimens, as well as lower dissimilarity of aquatic insect assemblages. Additionally, invasive macrophytes shifted the water pH and littoral depth of reservoir banks. The IndVal index indicated eight aquatic insects as indicator species. Labrundinia unicolor Silva, 2013, Ablabesmyia depaulai Neubern, 2013 and Diastatops Rambur, 1842 were indicator species on banks. We concluded that invasion of white ginger lily caused loss of shallow littoral habitat and altered the pH of the surrounding water probably by high decomposition rate and high production of plant biomass. We suggest the use of species of aquatic insects as indicator species to monitor white ginger lily impact in freshwater systems.

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...

Estimating cyclopoid copepod species richness and geographical distribution (Crustacea across a large hydrographical basin: comparing between samples from water column (plankton and macrophyte stands

Directory of Open Access Journals (Sweden)

Gilmar Perbiche-Neves

2014-06-01

Full Text Available Species richness and geographical distribution of Cyclopoida freshwater copepods were analyzed along the "La Plata" River basin. Ninety-six samples were taken from 24 sampling sites, twelve sites for zooplankton in open waters and twelve sites for zooplankton within macrophyte stands, including reservoirs and lotic stretches. There were, on average, three species per sample in the plankton compared to five per sample in macrophytes. Six species were exclusive to the plankton, 10 to macrophyte stands, and 17 were common to both. Only one species was found in similar proportions in plankton and macrophytes, while five species were widely found in plankton, and thirteen in macrophytes. The distinction between species from open water zooplankton and macrophytes was supported by nonmetric multidimensional analysis. There was no distinct pattern of endemicity within the basin, and double sampling contributes to this result. This lack of sub-regional faunal differentiation is in accordance with other studies that have shown that cyclopoids generally have wide geographical distribution in the Neotropics and that some species there are cosmopolitan. This contrasts with other freshwater copepods such as Calanoida and some Harpacticoida. We conclude that sampling plankton and macrophytes together provided a more accurate estimate of the richness and geographical distribution of these organisms than sampling in either one of those zones alone.

Landscapes of facilitation: how self-organized patchiness of aquatic macrophytes promotes diversity in streams.

Science.gov (United States)

Cornacchia, Loreta; van de Koppel, Johan; van der Wal, Daphne; Wharton, Geraldene; Puijalon, Sara; Bouma, Tjeerd J

2018-04-01

Spatial heterogeneity plays a crucial role in the coexistence of species. Despite recognition of the importance of self-organization in creating environmental heterogeneity in otherwise uniform landscapes, the effects of such self-organized pattern formation in promoting coexistence through facilitation are still unknown. In this study, we investigated the effects of pattern formation on species interactions and community spatial structure in ecosystems with limited underlying environmental heterogeneity, using self-organized patchiness of the aquatic macrophyte Callitriche platycarpa in streams as a model system. Our theoretical model predicted that pattern formation in aquatic vegetation - due to feedback interactions between plant growth, water flow and sedimentation processes - could promote species coexistence, by creating heterogeneous flow conditions inside and around the plant patches. The spatial plant patterns predicted by our model agreed with field observations at the reach scale in naturally vegetated rivers, where we found a significant spatial aggregation of two macrophyte species around C. platycarpa. Field transplantation experiments showed that C. platycarpa had a positive effect on the growth of both beneficiary species, and the intensity of this facilitative effect was correlated with the heterogeneous hydrodynamic conditions created within and around C. platycarpa patches. Our results emphasize the importance of self-organized patchiness in promoting species coexistence by creating a landscape of facilitation, where new niches and facilitative effects arise in different locations. Understanding the interplay between competition and facilitation is therefore essential for successful management of biodiversity in many ecosystems. © 2018 The Authors Ecology published by Wiley Periodicals, Inc. on behalf of Ecological Society of America.

Temporal changes in spatial patterns of submersed macrophytes in two impounded reaches of the Upper Mississippi River, USA, 1998-2009

Science.gov (United States)

De Jager, Nathan R.; Yin, Yao

2011-01-01

We examined temporal changes in spatial patterns of submersed aquatic macrophytes during a recent three-fold increase in macrophyte abundance and in response to the cumulative effects of management actions (island construction and water level management) and changes in regional environmental conditions (turbidity) in two navigation pools of the Upper Mississippi River, Pool 8 (managed) and Pool 13 (unmanaged). We used cross-correlograms to quantify changes in the degree and range of spatial correlation between submersed macrophytes and depth across the impounded portions of the two pools from 1998-2009. Along with increases in abundance, we observed gradual expansion of submersed macrophytes into deeper water in both pools. However, we detected no temporal change in spatial patterns in Pool 13, where the range of spatial correlation was ~ 1500-2500 m in length in the downriver direction and ~ 500-1000 m in length in the crossriver direction. We initially detected similar ranges of spatial correlation in Pool 8, but over time the range of correlation in the cross river direction increased from ~ 500 m in 1998 to ~ 2000 m by 2009. Thus, the expansion of submersed macrophytes into deeper water areas in Pool 8 appears to have occurred in the cross-river direction and led to increases in patch size and a more symmetrical patch configuration. Hence, very similar temporal changes in submersed macrophyte abundance corresponded with different diffusion dynamics and spatial patterns in the two pools. We hypothesize that management actions altered spatial patterns of depth, water flow and/or wind fetch and led to the differences in spatial patterns reported here.

Fish assemblage dynamics in a Neotropical floodplain relative to aquatic macrophytes and the homogenizing effect of a flood pulse

Science.gov (United States)

Gomes, L.C.; Bulla, C. K.; Agostinho, A. A.; Vasconcelos, L. P.; Miranda, Leandro E.

2012-01-01

The presence of aquatic macrophytes is a key factor in the selection of habitats by fish in floodplain lakes because these plants enhance the physical and biological complexities of aquatic habitats. The seasonal flood pulse may influence this interaction, but there is no information in the literature about the effects that flood events may have on macrophytes assemblages and its associated effects on fish assemblages. Thus, this article aimed to investigate whether species richness, evenness and similarities in fish assemblage composition differed between littoral areas vegetated with macrophytes and unvegetated areas, before and after a flood. We sampled three lakes in the floodplain of the upper Paraná River basin. Sampling was conducted before (December 2004 and January 2005) and after (early March, late March and May 2005) a flood event. Overall, species richness and evenness were higher in macrophytes-covered areas. Before the flood, the composition of fish assemblages was distinct when comparing vegetated and unvegetated areas. After the flood, the similarity in fish assemblage composition was higher, indicating a homogenization effect of floods for fish inhabiting littoral areas of floodplain lakes. After the flood, opportunistic species dominated the fish assemblages in aquatic macrophytes, apparently restructuring assemblages in the littoral, restarting a succession process. Thus, the observed homogenization effect of the flood could minimize biological interactions and could induce fish assemblages to begin a new process of structurization.

Impact of Invertebrate Herbivory on Native Aquatic Macrophytes

Science.gov (United States)

2007-08-01

this macroalga occupied the entire water column, it may have had a competitive advantage for light over V. americana, which grew closer to the...dry biomass of five macrophyte species between two treatments ; an insecticide treatment to remove invertebrate herbivores, and a control where the...Heitmeyer and Vohs 1984, Dibble et al. 1996), improve water clarity and quality, and reduce rates of shoreline erosion and sediment resuspension (Smart

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

Temporal changes of aquatic macrophytes vegetation in a Iowland groundwater feed eutrophic course (Klátovské rameno, Slovakia

Directory of Open Access Journals (Sweden)

Helena Oťahel'ová

2011-01-01

Full Text Available Klátovské rameno is the lowland slow-flowing groundwater feed eutrophic tributary of the Malý Dunaj River (Danube Plain, where our study of temporal changes of aquatic macrophytes vegetation was realised in 1999 and 2005. For survey of aquatic vascular macrophytes the Kohler’s method (Janauer 2003 was used, which is compliant with European standard EN 14184. Altogether 35 aquatic macrophyte species were recorded during the survey. Nuphar lutea persisted as the most dominant species in 1996 and 2005. Species diversity increased slightly after the nine years: ten species immigrated to the watercourse. The changes in species abundance have shown weak differences, however the abundance of Sparganium emersum has increased markedly. Alien species Elodea canadensis and both S. emersum and Hydrocharis morsus-ranae significantly enlarged their distribution in the stream. The ecological quality of the river, based on the aquatic macrophytes assessment criteria, was slightly impaired after nine years, but still 90% of its studied course has a high or good ecological status.

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.

Submersed macrophytes as indicators of the nutrient burden of Lake Constance (Untersee)

International Nuclear Information System (INIS)

Schmieder, K.

1992-01-01

Most of the submersed species react sensitively to changes in the site conditions during the investigation period; this shows the high value of submersed macrophytes as biological indicators of water pollution. (orig./EF) [de

Emergent and floating-leaved macrophytes as refuge for zooplankton in a eutrophic temperate lake without submerged vegetation

DEFF Research Database (Denmark)

Cazzanelli, Matteo; Perlt, Trine Warming; Christoffersen, Kirsten Seestern

2008-01-01

Several studies have shown that submerged macrophytes provide a refuge for zooplankton against fish predation, whereas the role of emergent and floating-leaved species, which are often dominant in eutrophic turbid lakes, is far less investigated. Zooplankton density in open water and amongst....... As a consequence, especially in turbid lakes, the ecological role of these functional types of vegetation, and not merely that of submerged macrophyte species, should be taken into consideration....

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.

A preliminary study of the feasibility of detecting the floating macrophytes by means of digital processing of MSS/LANDSAT data

Science.gov (United States)

Valeriano, D. D. (Principal Investigator)

1984-01-01

The feasibility of mapping the floating macrophytes (mostly water hyacinth: (Eichornia crassipes) in the Salto Grande reservoir in Americana, SP, by means of digital processing of MSS/LANDSAT data is described. The area occupied by the macrophytes was extracted by exclusion after the merging of two thematic masks representing the area of vegetation free water surface. One of the masks was obtained from a date when the vegetal cover is insignificant, while the other represents a large infestation episode. The utilization of digital processing of MSS/LANDSAT data techniques for the documentation of macrophytes infestation is feasible only when the phenomenon occurs in large areas.

Influence of Disturbance on Habitats and Biological Communities in Lowland Streams

DEFF Research Database (Denmark)

Pedersen, Morten Lauge; Friberg, N.

2009-01-01

). The results indicate that disturbance cascades through the stream ecosystem, primarily meditated by changes in macrophyte communities that are essential providers of habitat in unshaded lowland streams in which other structural elements, as coarse inorganic substrates and woody debris, are scarce...

Macrophyte and pH buffering updates to the Klamath River water-quality model upstream of Keno Dam, Oregon

Science.gov (United States)

Sullivan, Annett B.; Rounds, Stewart A.; Asbill-Case, Jessica R.; Deas, Michael L.

2013-01-01

A hydrodynamic, water temperature, and water-quality model of the Link River to Keno Dam reach of the upper Klamath River was updated to account for macrophytes and enhanced pH buffering from dissolved organic matter, ammonia, and orthophosphorus. Macrophytes had been observed in this reach by field personnel, so macrophyte field data were collected in summer and fall (June-October) 2011 to provide a dataset to guide the inclusion of macrophytes in the model. Three types of macrophytes were most common: pondweed (Potamogeton species), coontail (Ceratophyllum demersum), and common waterweed (Elodea canadensis). Pondweed was found throughout the Link River to Keno Dam reach in early summer with densities declining by mid-summer and fall. Coontail and common waterweed were more common in the lower reach near Keno Dam and were at highest density in summer. All species were most dense in shallow water (less than 2 meters deep) near shore. The highest estimated dry weight biomass for any sample during the study was 202 grams per square meter for coontail in August. Guided by field results, three macrophyte groups were incorporated into the CE-QUAL-W2 model for calendar years 2006-09. The CE-QUAL-W2 model code was adjusted to allow the user to initialize macrophyte populations spatially across the model grid. The default CE-QUAL-W2 model includes pH buffering by carbonates, but does not include pH buffering by organic matter, ammonia, or orthophosphorus. These three constituents, especially dissolved organic matter, are present in the upper Klamath River at concentrations that provide substantial pH buffering capacity. In this study, CE-QUAL-W2 was updated to include this enhanced buffering capacity in the simulation of pH. Acid dissociation constants for ammonium and phosphoric acid were taken from the literature. For dissolved organic matter, the number of organic acid groups and each group's acid dissociation constant (Ka) and site density (moles of sites per mole of

Enhanced phosphorus reduction in simulated eutrophic water: a comparative study of submerged macrophytes, sediment microbial fuel cells, and their combination.

Science.gov (United States)

Xu, Peng; Xiao, Enrong; Xu, Dan; Li, Juan; Zhang, Yi; Dai, Zhigang; Zhou, Qiaohong; Wu, Zhenbin

2018-05-01

The phosphorus reduction in water column was attempted by integrating sediment microbial fuel cells (SMFCs) with the submerged macrophyte Vallisneria spiralis. A comparative study was conducted to treat simulated water rich in phosphate with a control and three treatments: SMFC alone (SMFC), submerged macrophytes alone (macophyte), and combined macrophytes and fuel cells (M-SMFC). All treatments promoted phosphorus flux from the water column to sediments. Maximum phosphorus reduction was obtained in proportion to the highest stable phosphorus level in sediments in M-SMFC. For the initial phosphate concentrations of 0.2, 1, 2, and 4 mg/L, average phosphate values in the overlying water during four phases decreased by 33.3% (25.0%, 8.3%), 30.8% (5.1%, 17.9%), 36.5% (27.8%, 15.7%), and 36.2% (0.7%, 22.1%) for M-SMFC (macrophyte, SMFC), compared with the control. With macrophyte treatment, the obvious phosphorus release from sediments was observed during the declining period. However, such phenomenon was significantly inhibited with M-SMFC. The electrogenesis bacteria achieved stronger phosphorus adsorption and assimilation was significantly enriched on the closed-circuit anodes. The higher abundance of Geobacter and Pseudomonas in M-SMFC might in part explain the highest phosphorus reduction in the water column. M-SMFC treatment could be promising to control the phosphorus in eutrophic water bodies.

Impacts of Mechanical Macrophyte Removal Devices on Sediment Scouring in Littoral Habitats: II. Experimental Operation in the Littoral Zone of Eau Galle Reservoir, Wisconsin

National Research Council Canada - National Science Library

James, William F; Wright, David I; Barko, John W; Eakin, Harry L

2006-01-01

... in Eau Galle Reservoir, Wisconsin. Mechanical macrophyte removal devices are an attractive, low-cost means of removing macrophytes in specific areas without herbicides or repeated mechanical harvesting...

Macroinvertebrate communities associated with littoral zone habitats and the influence of environmental factors in Malilangwe Reservoir, Zimbabwe

Directory of Open Access Journals (Sweden)

Dalu T.

2012-10-01

Full Text Available The aim of our study was to investigate macroinvertebrate communities so as to understand factors and processes structuring macroinvertebrate communities in a small reservoir, Malilangwe reservoir over seven months (April to October. Sampling was performed by active sweep netting and searching soil sediments. Water temperature, conductivity, dissolved oxygen, pH, ammonia, nitrogen, phosphorus, chemical oxygen demand and macrophyte cover were determined. In total, forty-two macroinvertebrate families belonging to 10 orders were identified amongst 13 macrophyte species and sediments. Thiaridae and Physidae (Mollusca were the dominant and most abundant taxa (57.71% and there were followed by the Hemiptera (27.31%. High indices for sites 1 to 3 for the Simpsons index, the Shannon-Weaver index and evenness were recorded, while low indices were observed for sites 4 to 5, with significant differences being observed among the study site using the Kruskal-Wallis ANOVA test (p < 0.05. Redundancy Analysis revealed that among environmental factors, hydrologically linked parameters such as conductivity, water level and macrophyte cover had the strongest influence on macroinvertebrate distribution.

The zooplankton community of Lake Abo Zaabal, a newly-formed ...

African Journals Online (AJOL)

Cladocera were seldom recorded. Hexarthra, Brachionus and Rotaria were the dominant rotifer taxa. Several characteristics — including the community composition, the dominance of small ciliates and nauplii, the abundance of Cyanobacteria, and the absence of macrophytes — indicated that it is a severely eutrophic lake.

The distribution of radionuclides between the sediments and macrophytes in the cooling pond of the Ignalina NPP - The Distribution of Radionuclides in Freshwater Hydro Ecosystem's Bottom Sediments and Macrophytes depending on the Ecological Conditions

Energy Technology Data Exchange (ETDEWEB)

Marciulioniene, D.; Jefanova, O.; Mazeika, J. [Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius, Lietuva (Lithuania)

2014-07-01

The distribution of {sup 137}Cs, {sup 60}Co, {sup 54}Mn in the aquatory of lake Drukshiai (the monitoring stations), the coastal area of this lake, the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP was analyzed on the basis of long-term (1988-2009) investigations of radionuclides specific activity in bottom sediments and macrophytes, also the ability of radionuclides falling into lake Drukshiai from the Ignalina NPP through effluents channels was assessed. It was established that {sup 137}Cs, {sup 60}Co and {sup 54}Mn in the bottom sediments and the macrophytes were distributed quite differently in the monitoring stations of lake Drukshiai and the coastal area as well as in the industrial drainage systems channel of the Ignalina NPP and the cooling water channel of the Ignalina NPP. The different characteristics of the sediments, various ecological conditions, as well as the existing anthropogenic environmental factors and the different in the ecological groups of the plants could have had impact on the distribution of {sup 137}Cs, {sup 60}Co and {sup 54}Mn in the bottom sediments and the aquatic plants in lake Drukshiai and the effluents channels of the Ignalina NPP. The {sup 137}Cs, {sup 60}Co and {sup 54}Mn specific activity's values were significantly higher in macrophytes from the industrial drainage systems channel of Ignalina NPP than in macrophytes from the cooling water channel. Nevertheless the specific activities level of these radionuclides differed only slightly in the macrophytes from the areas which were impacted by the effluents channels of the Ignalina NPP. This can be explained by the fact that the phyto-remediation (as the form of auto-purification) of these effluents from the radionuclides had been present in the industrial drainage systems channel of Ignalina NPP before entering the water into lake Drukshiai. (authors)

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

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 ...

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.

Microcystin production in epiphytic cyanobacteria on submerged macrophytes.

Science.gov (United States)

Mohamed, Zakaria A; Al Shehri, Abdulrahman M

2010-06-15

Cyanotoxins have been largely studied in planktonic and benthic cyanobacteria, but microcystin (MCYST) production in epiphytic cyanobacteria has not been reported yet. The present study reports for the first time the MCYST production in epiphytic cyanobacteria on submerged macrophytes. During this study, four common submerged macrophytes in eutrophic pond in Saudi Arabia were surveyed for the presence of toxic epiphytic cyanobacteria. The results showed that chlorophyll-a and total biovolume of epiphytic cyanobacteria differed significantly among submerged plants with highest values obtained in Stratiotes aloides and lowest in Elodea canadensis. Epiphytic materials collected from Ceratophyllum demersum and S. aloides had higher species diversities than materials collected from E. canadensis and Myriophyllum verticillatum. The cyanobacteria, Merismopedia tenuissima and Leptolyngbya boryana were recorded with a high abundance in epiphytic materials collected from all submerged macrohpytes. Based on Enzyme-linked immunosorbent assay (ELISA), these two species were found to produce MCYSTs (MCYSTs) with concentrations of 1438 and 630 microg g(-1) dry weight, respectively. HPLC analysis of the methanolic extracts of the two species showed that M. tenuissima extract contained MCYST-RR and -LR/demethyl LR plus 3 minor unidentified MCYSTs, while L. boryana extract contained MCYST-YR, -LR/demethyl LR, and 2 minor unidentified MCYSTs. This study suggests that epiphytic species should be considered during monitoring of toxic cyanobacteria in water sources. 2010 Elsevier Ltd. All rights reserved.

Spatial patterns of heavy metal accumulation in sediments and macrophytes of Bellandur wetland, Bangalore.

Science.gov (United States)

Ramachandra, T V; Sudarshan, P B; Mahesh, M K; Vinay, S

2018-01-15

Heavy metals are one among the toxic chemicals and accumulation in sediments and plants has been posing serious health impacts. Wetlands aid as kidneys of the landscape and help in remediation through uptake of nutrients, heavy metals and other contaminants. The analyses of macrophytes and sediment samples help in evaluating pollution status in aquatic environment. In this study concentration of six heavy metals (Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb) and Zinc (Zn)) were assessed in sediment and dominant macrophyte samples collected from Bellandur Lake, largest Lake of Bangalore, India. Sediment samples reveal of heavy metals in the inlet regions and shore samples. The accumulation of metals in sediments were in the order of Zn > Cu > Cr > Pb > Ni > Cd. All metals exceeded the critical limits of metals in the sediment. Concentration of different metals in the macrophyte samples ranked as: Cr > Cu > Zn > Pb > Ni > Cd. Chromium and Copper were found to be more than critical range. Typha angustata had the higher accumulation of all metals except chromium. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Influence of Coal Ash Leachates and Emergent Macrophytes on Water Quality in Wetland Microcosms

Data.gov (United States)

U.S. Environmental Protection Agency — Influence of Coal Ash Leachates and Emergent Macrophytes on Water Quality in Wetland Microcosms. This dataset is associated with the following publication: Olson,...

The impact of an industrial effluent on the water quality, submersed macrophytes and benthic macroinvertebrates in a dammed river of Central Spain.

Science.gov (United States)

Gonzalo, Cristina; Camargo, Julio A

2013-10-01

This research was conducted in the middle Duratón River (Central Spain), in the vicinity of Burgomillodo Reservoir. An industrial effluent enters the river 300 m downstream from the dam. Fluoride and turbidity levels significantly increased downstream from the effluent, these levels being to some extent affected by differential water releases from the dam. The community of submersed macrophytes exhibited slighter responses and, accordingly, lower discriminatory power than the community of benthic macroinvertebrates, this indicating that metrics and indices based on macroinvertebrates may be more suitable for the biological monitoring of water pollution and habitat degradation in dammed rivers receiving industrial effluents. However, in relation to fluoride bioaccumulation at the organism level, macrophytes (Fontinalis antipyretica and Potamogeton pectinatus) were as suitable bioindicators of fluoride pollution as macroinvertebrates (Ancylus fluviatilis and Pacifastacus leniusculus). Fluoride bioaccumulation in both hard and soft tissues of these aquatic organisms could be used as suitable bioindicator of fluoride pollution (even lower than 1 mg F(-)L(-1)) in freshwater ecosystems. Echinogammarus calvus exhibited a great sensitivity to the toxicity of fluoride ions, with a 96 h LC₅₀ of 7.5 mg F(-)L(-1) and an estimated safe concentration of 0.56 mg F(-)L(-1). The great capacity of E. calvus to take up and retain fluoride during exposures to fluoride ions would be a major cause of its great sensitivity to fluoride toxicity. It is concluded that the observed fluoride pollution might be partly responsible for the absence of this native amphipod downstream from the industrial effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Uranium accumulation by aquatic macrophyte, Pistia stratiotes

International Nuclear Information System (INIS)

Bhainsa, K.C.; D'Souza, S.F.

2012-01-01

Uranium accumulation by aquatic macrophyte, Pistia stratiotes from aqueous solution was investigated in laboratory condition. The objective was to evaluate the uranium accumulation potential and adopt the plant in uranium containing medium to improve its uptake capacity. The plant was found to tolerate and grow in the pH range of 3-7. Accumulation of uranium improved with increasing pH and the plant could remove 70% uranium from the medium (20 mg/L) within 24 hours of incubation at pH 5-6. Uptake of uranium on either side of this pH range decreased

Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies--effects of macrophytes.

Science.gov (United States)

Chen, Xijuan; Pauly, Udo; Rehfus, Stefan; Bester, Kai

2009-10-15

Sludge reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Europe since 1988. Although reed beds are considered as a low cost and low contamination method in reducing volume, breaking down organic matter and increasing the density of sludge, it is not yet clear whether this enhanced biological treatment is suitable for degradation of organic micro-pollutants such as personal care products. Within this project the effect of biological sludge treatment in a reed bed on reducing the concentrations of the fragrances HHCB, AHTN, OTNE was studied as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted into containers (lysimeters) with a size of 1 m x 1 m x 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years for reed beds, an assessment was made for the whole life time.

Distribution of stable and radioactive metals among the biomass compartments of the macrophytes of the Yenisei river and estimation of the dose rate

International Nuclear Information System (INIS)

Zotina, T.A.; Bolsunovskiy, A.Ya.; Sukovatyj, A.G.

2008-01-01

Artificial radioactive metals are annually detected in the biomass of submerged macrophytes in the zone radioactive contamination of the Yenisei river. It has been shown by other authors that metals are not uniformly distributed in the biomass of aquatic macrophytes. In this research the distribution of stable and radioactive isotopes of metals was investigated among the biomass compartments of the macrophytes from the Yenisei river with chemical fractionation technique. Dose rates from the intra- and extracellular radionuclides have been estimated. According to the data obtained the distribution of metals among intra- and extracellular compartments was different. The major portion of Co, Mn and Zn was accumulated in the biomass in more mobile form, than Cr and Fe. Artificial radioactive isotopes were detected in the same compartments as stable metals. Essential portion of artificial radionuclides and stable metals was detected in the particles of seston, attached to the surface of the macrophytes.

Comparability of river quality assessment using macrophytes: a multi-step procedure to overcome biogeographical differences.

Science.gov (United States)

Aguiar, F C; Segurado, P; Urbanič, G; Cambra, J; Chauvin, C; Ciadamidaro, S; Dörflinger, G; Ferreira, J; Germ, M; Manolaki, P; Minciardi, M R; Munné, A; Papastergiadou, E; Ferreira, M T

2014-04-01

This paper exposes a new methodological approach to solve the problem of intercalibrating river quality national methods when a common metric is lacking and most of the countries share the same Water Framework Directive (WFD) assessment method. We provide recommendations for similar works in future concerning the assessment of ecological accuracy and highlight the importance of a good common ground to make feasible the scientific work beyond the intercalibration. The approach herein presented was applied to highly seasonal rivers of the Mediterranean Geographical Intercalibration Group for the Biological Quality Element Macrophytes. The Mediterranean Group of river macrophytes involved seven countries and two assessment methods with similar acquisition data and assessment concept: the Macrophyte Biological Index for Rivers (IBMR) for Cyprus, France, Greece, Italy, Portugal and Spain, and the River Macrophyte Index (RMI) for Slovenia. Database included 318 sites of which 78 were considered as benchmarks. The boundary harmonization was performed for common WFD-assessment methods (all countries except Slovenia) using the median of the Good/Moderate and High/Good boundaries of all countries. Then, whenever possible, the Slovenian method, RMI was computed for the entire database. The IBMR was also computed for the Slovenian sites and was regressed against RMI in order to check the relatedness of methods (R(2)=0.45; p<0.00001) and to convert RMI boundaries into the IBMR scale. The boundary bias of RMI was computed using direct comparison of classification and the median boundary values following boundary harmonization. The average absolute class differences after harmonization is 26% and the percentage of classifications differing by half of a quality class is also small (16.4%). This multi-step approach to the intercalibration was endorsed by the WFD Regulatory Committee. © 2013 Elsevier B.V. All rights reserved.

Climate-related differences in the dominance of submerged macrophytes in shallow lakes

NARCIS (Netherlands)

Kosten, S.; Kamarainen, A.; Jeppesen, E.; Nes, van E.H.; Peeters, E.T.H.M.; Lacerot, G.; Scheffer, M.

2009-01-01

It has been suggested that shallow lakes in warm climates have a higher probability of being turbid, rather than macrophyte dominated, compared with lakes in cooler climates, but little field evidence exists to evaluate this hypothesis. We analyzed data from 782 lake years in different climate zones

Macrophytes as bioindicators of heavy metal pollution in estuarine and coastal environments.

Science.gov (United States)

Farias, D R; Hurd, C L; Eriksen, R S; Macleod, C K

2018-03-01

The Derwent estuary, in Tasmania (Australia), is highly contaminated with heavy metals with significant levels in both sediments and benthic fauna. However, little is known about metal content in benthic primary producers. We characterized metal content (Arsenic, Cadmium, Copper, Lead, Selenium and Zinc) in twelve species of macrophyte, including red, green, and brown algae, and seagrasses, from the Derwent. The metals, arsenic, copper, lead, and Zinc were detected in all of the macrophytes assessed, but the levels differed between species. Seagrasses accumulated the highest concentrations of all metals; with Zn levels being particularly high in the seagrass Ruppia megacarpa (from the upper Estuary) and Pb was detected in Zostera muelleri (from the middle estuary). Ulva australis was ubiquitous throughout the middle-lower estuary and accumulated Zn in relatively high concentrations. The findings suggest that analysis of multiple species may be necessary for a comprehensive understanding of estuary-wide metal pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kinetics of Cr(III) and Cr(VI) removal from water by two floating macrophytes.

Science.gov (United States)

Maine, M A; Hadad, H R; Sánchez, G; Caffaratti, S; Pedro, M C

2016-01-01

The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L(-1) of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work.

The role of emergent vegetation in structuring aquatic insect communities in peatland drainage ditches

NARCIS (Netherlands)

Whatley, M.H.; van Loon, E.E.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.

2014-01-01

Availability of macrophyte habitat is recognized as an important driver of aquatic insect communities in peatland drainage ditches; however, eutrophication can lead to the decline of submerged vegetation. While emergent vegetation is able to persist in eutrophicated ditches, vegetation removal,

Phytoremediation of anatoxin-a by aquatic macrophyte Lemna trisulca L.

Science.gov (United States)

Kaminski, Ariel; Bober, Beata; Chrapusta, Ewelina; Bialczyk, Jan

2014-10-01

The neurotoxin anatoxin-a (ANTX-a), one of the most common cyanotoxin, poses a health risk to people and can be lethal to aquatic organisms. This paper presents results on its bioremediation by the aquatic macrophyte Lemna trisulca. We show that the plant is resistant to the harmful impact of toxin and is capable of removing ANTX-a from water. Some of the ANTX-a concentrations which were used in our experiments were much higher than those found in natural conditions. The exposition of L. trisulca to 2.5 μg ANTX-a/mL did not affect its biomass accumulation within 24 d. Significant decreases in biomass content by 21% and 30% were demonstrated in samples cultivated in media containing 12.5 μg ANTX-a/mL after 18 and 24 day of experiment, respectively. One gram of fresh weight (f.w.) of L. trisulca cultured for 14 d in the media containing 50 μg ANTX-a removed 95% of the initial toxin concentration; for media with 250 μg ANTX-a, 86% was removed. In tests of ANTX-a binding stability and degradation we transferred the macrophyte to fresh media without added toxin; within 14 d the content of accumulated ANTX-a in the macrophyte decreased by 76% (from initial 19.3 μg ANTX-a/gf.w.), 71% (from 37.3 μg ANTX-a/g f.w.) and 47% (from 63.7 μg ANTX-a/g f.w.). The quantity of ANTX-a released to media was minimal: from 3.5% to 5.1% of the initial bioaccumulated value. The data show that part of the ANTX-a was degraded. Mass spectra analyses did not indicate transformation of ANTX-a to already known forms. These findings suggest that L. trisulca has much potential as a phytoremediation agent for stabilization of aquatic environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity

International Nuclear Information System (INIS)

Hanson, Mark L.; Solomon, Keith R.

2004-01-01

Haloacetic acids (HAAs) are contaminants of aquatic ecosystems with numerous sources, both anthropogenic and natural. The toxicity of HAAs to aquatic plants is generally uncharacterized. Laboratory tests were conducted with three macrophytes (Lemna gibba, Myriophyllum sibiricum and Myriophyllum spicatum) to assess the toxicity of five HAAs. Myriophyllum spp. has been proposed as required test species for pesticide registration in North America, but few studies have been conducted under standard test conditions. The HAAs in the present experiments were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). MCA was the most toxic to Myriophyllum spp. with EC 50 values ranging from 8 to 12.4 mg/l depending on the endpoint, followed by DCA (EC 50 range 62-722.5 mg/l), TCA (EC 50 range 49.5-1702.6 mg/l), CDFA (EC 50 range 105.3 to >10,000 mg/l) and with TFA (EC 50 range 222.1 to 10,000 mg/l) the least toxic. Generally, L. gibba was less sensitive to HAA toxicity than Myriophyllum spp., with the difference in toxicity between them approximately threefold. The range of toxicity within Myriophyllum spp. was normally less than twofold. Statistically, plant length and node number were the most sensitive endpoints as they had the lowest observed coefficients of variation, but they were not the most sensitive to HAA toxicity. Toxicological sensitivity of endpoints varied depending on the measure of effect chosen and the HAA, with morphological endpoints usually an order of magnitude more sensitive than pigments for all plant species. Overall, mass and root measures tended to be the most sensitive indicators of HAA toxicity. The data from this paper were subsequently used in an ecological risk assessment for HAAs and aquatic plants. The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series

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

Molecular characterization of macrophyte-derived dissolved organic matters and their implications for lakes

Science.gov (United States)

Chemical properties of whole organic matter (OM) and its dissolved organic matter (DOM) fraction from six dominant macrophytes in Lake Dianchi were comparatively characterized, and their environmental implications were discussed. Significant differences in chemical composition of the OM samples were...

Fish associated with aquatic macrophytes in the Chacororé-Sinhá Mariana Lake system and Mutum River, Pantanal of Mato Grosso, Brazil.

Science.gov (United States)

Pacheco, E B; Da-Silva, C J

2009-02-01

On the left bank of the Cuibá River, one of the main tributaries of the Pantanal in Mato Grosso, are located the Chacororé and Sinhá Mariana Lakes and the Mutum River, the littoral regions of which are covered with aquatic macrophytes, dominated by the species Eichhornia crassipes and Eichhornia azurea. To examine the ichthyofauna associated with this vegetation, in the year 2003, 3510 fish were collected, distributed among 83 species, and the limnological variables verified near the macrophyte stands where they were sampled. The most abundant and richest order was the Characiformes, followed by the Gymnotiformes and Siluriformes. Analysis of similarity showed a very low, or null, index that the limnological conditions and morphology of the aquatic macrophyte species provide habitat sufficiently homogeneous to give. The limnological conditions and morphology of the aquatic macrophyte species provide a sufficient habitat heterogeneity to give very low, or null, index values. Thus, environmental conservation measures should be more effective in promoting the conservation of the species, given the high levels of biological diversity found in the habitats studied.

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 NH 3 -N and organic nitrogen while those from cattail litter included organic nitrogen and NO 3 - -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.

A simple equation for describing the temperature dependent growth of free-floating macrophytes

NARCIS (Netherlands)

Heide, van Tj.; Roijackers, R.M.M.; Nes, van E.H.; Peeters, E.T.H.M.

2006-01-01

Temperature is one of the most important factors determining growth rates of free-floating macrophytes in the field. To analyse and predict temperature dependent growth rates of these pleustophytes, modelling may play an important role. Several equations have been published for describing

Genotoxicity evaluation of the insecticide endosulfan in the wetland macrophyte Bidens laevis L

International Nuclear Information System (INIS)

Perez, Debora J.; Menone, Mirta L.; Camadro, Elsa L.; Moreno, Victor J.

2008-01-01

The frequency of micronuclei (MN) and chromosome aberrations in anaphase-telophase (CAAT) was determined in root tips of the wetland macrophyte Bidens laevis exposed to environmentally relevant concentrations of endosulfan (0.01, 0.02, 0.5 and 5 μg/L) for 48 h. MN frequency varied from 0 in negative controls and plants exposed to 0.01 μg/L endosulfan to 0-3 in plants exposed to 5 μg/L. Moreover, a significant concentration-dependent increase of CAAT was observed. The higher proportion of laggards and vagrand chromosomes observed at 5 μg/L would indicate that endosulfan interacts with the spindle interrupting normal chromosome migration. Endosulfan resulted genotoxic to B. laevis, a species of potential value for bioassays and in situ monitoring of environmental contamination by pesticides. - Endosulfan causes a concentration-dependent increase of chromosome aberrations in the macrophyte Bidens laevis

Application of Elovich equation on uptake kinetics of 137Cs by living freshwater macrophytes - a short duration laboratory study

International Nuclear Information System (INIS)

Jaison, T.J.; Patra, A.K.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Application of Elovich equation on uptake kinetics of 137 Cs by two living macrophytes during controlled experiments on short duration exposure is studied. Compliance to 2 nd order kinetics indicates the mechanism could be chemi-sorption, involving polar functional groups present on the extracelluar surface of the macrophytes. Data analysis suggests that Myriophyllum s. exhibits faster adsorption rate than Hydrilla v. As Myriophyllum s. exhibits better kinetics than Hydrilla v., former could be a better natural adsorbing media for 137 Cs. (author)

How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products.

Science.gov (United States)

Hommen, Udo; Schmitt, Walter; Heine, Simon; Brock, Theo Cm; Duquesne, Sabine; Manson, Phil; Meregalli, Giovanna; Ochoa-Acuña, Hugo; van Vliet, Peter; Arts, Gertie

2016-01-01

This case study of the Society of Environmental Toxicology and Chemistry (SETAC) workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard European Union (EU) risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analyzed using effect models for 2 aquatic macrophytes, the free-floating standard test species Lemna sp., and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests, whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for 2 exposure scenarios, while confirming the risk associated for the third. Uncertainties related to the experimental and the modeling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that 1) ecological scenarios be developed that are also

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.

A meta-analysis of water quality and aquatic macrophyte responses in 18 lakes treated with lanthanum modified bentonite (Phoslock(®)).

Science.gov (United States)

Spears, Bryan M; Mackay, Eleanor B; Yasseri, Said; Gunn, Iain D M; Waters, Kate E; Andrews, Christopher; Cole, Stephanie; De Ville, Mitzi; Kelly, Andrea; Meis, Sebastian; Moore, Alanna L; Nürnberg, Gertrud K; van Oosterhout, Frank; Pitt, Jo-Anne; Madgwick, Genevieve; Woods, Helen J; Lürling, Miquel

2016-06-15

398 cm to 506 cm, respectively. Aquatic macrophyte species numbers and maximum colonisation depths increased following La-bentonite application from a median of 5.5 species to 7.0 species and a median of 1.8 m to 2.5 m, respectively. The aquatic macrophyte responses varied significantly between lakes. La-bentonite application resulted in a general improvement in water quality leading to an improvement in the aquatic macrophyte community within 24 months. However, because, the responses were highly site-specific, we stress the need for comprehensive pre- and post-application assessments of processes driving ecological structure and function in candidate lakes to inform future use of this and similar products. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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.

Exocellular electron transfer in anaerobic microbial communities

NARCIS (Netherlands)

Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

2006-01-01

Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

Floating macrophytes on the wastewater treatment: a state of the art review Macrófitas flotantes en el tratamiento de aguas residuales: una revisión del estado del arte

OpenAIRE

Jorge Martelo; Jaime A Lara Borrero

2012-01-01

The wastewater treatments with floating macrophytes have proven effective in the remediation of waters with nutrient content, organic matter and toxic substances such as arsenic, zinc, cadmium, copper, lead, chromium, and mercury. Its importance lies in its ability to be used in rural communities due to their low consumption of conventional energy and practicality in the assembly and operation of treatment systems. Still, it has not been clarified thoroughly the processes taking place in the pur...

Arsenic levels in the soils and macrophytes of the 'Entremuros' after the Aznalcollar mine spill

International Nuclear Information System (INIS)

Taggart, M.A.; Carlisle, M.; Pain, D.J.; Williams, R.; Green, D.; Osborn, D.; Meharg, A.A.

2005-01-01

In April 1998, a holding lagoon containing pyrite ore processing waste rich in arsenic, failed and released 5-6 million m 3 of highly polluting sludge and acidic water. Over 2700 ha of the internationally important Don-tilde ana National and Natural Parks were contaminated. The area of Natural Park to sustain the greatest impact was known as the Entremuros. This paper presents 0-5 cm soil monitoring data from the Entremuros, from sampling campaigns 6 and 18 months after the disaster; as well as macrophyte root, rhizome and stem data from samples taken 18 months after the spill. Results show a clear, decreasing, north-south arsenic soil pollution trend, both 6 and 18 months after the spill, and suggest a small reduction in total soil arsenic levels occurred over time; although a significant increase in extractable arsenic is also noted. The two macrophytes (Typha dominguensis and Scirpus maritimus) studied herein are not accumulating arsenic in stem parts, however, accumulation of arsenic on iron plaque on the roots of these plants may be occurring. Further work is recommended in order to determine the ecotoxicological significance of this process in relation to the avian food-chains of Don-tilde ana, and elsewhere. - Capsule: Arsenic associated with iron plaque on macrophyte roots may pose an ecotoxicological risk to certain herbivores

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

OpenAIRE

Roger Paulo Mormul; Fernando Alves Ferreira; Thaisa Sala Michelan; Priscilla Carvalho; Marcio José Silveira; Sidinei Magela Thomaz

2010-01-01

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 ...

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.

Ultraviolet-induced responses in two species of climax tropical marine macrophytes.

Science.gov (United States)

Detrés, Y; Armstrong, R A; Connelly, X M

2001-09-01

In tropical regions nominal reductions in stratospheric ozone could be detrimental to marine organisms that live near their upper tolerance levels of ultraviolet (UV) radiation and temperature. Well-known plant responses to UV include inhibition of photosynthesis, reductions in chlorophyll content, morphological changes and production of UV absorbing compounds such as flavonoids. An assessment of the effects and responses of two tropical marine macrophytes to full solar radiation and solar radiation depleted of UV were conducted in southwestern Puerto Rico. Changes in concentration of photosynthetic and photoprotective pigments, and in leaf optical properties of the red mangrove Rhizophora mangle and the seagrass Thalassia testudinum, were evaluated in field exclusion experiments. Rhizophora mangle exposed to full solar radiation showed lower leaf reflectance and a shift of 5 nm in the inflection point of the red edge. Thalassia testudinum samples excluded from UV had significant increases in total chlorophyll and carotenoid concentrations. These marine macrophytes showed increments in their concentration of UV-B absorbing compounds with exposure to UV radiation. Results indicate that even minor increases in UV radiation at low latitudes could have significant effects on the pigment composition of these climax species.

Trace element concentrations in freshwater mussels and macrophytes as related to those in their environment

Directory of Open Access Journals (Sweden)

Gian Maria BEONE

2003-02-01

Full Text Available This study was primarily designed to contribute to the debate "Do accumulator species reflect the element contamination level of their environment?" This research was carried out: 1 to know the distribution of 15 trace elements and calcium in shell and soft tissues of three species of freshwater mussels and macrophytes; 2 to compare the accumulation capacity of each trace element by mussels and by eight species of macrophytes and 3 to test the relationships between the metal concentrations in the mussels and macrophytes and those in water and sediments. The variability of element residues in the mussels is the major limit to accumulator monitoring. The most important causes are: seasonal cycle, physical environment and biological factors such as the size, age and growth rate. This research was designed to eliminate the consequence of variability deriving from the season and the environment. To this end the mussels and macrophytes were collected at the same time from the same habitat: Ranco Bay, Lago Maggiore, Northern Italy. In addition, the element concentrations in more size-classes of the most abundant mussel species (Unio pictorum and Dreissena polymorpha were measured. Trace elements were analyzed by Inductive Coupled Plasma-Mass Spectrometry (ICP-MS. By arranging the data in sequences of decreasing element concentrations in the organisms as well as in water and sediments, we were able to compare the accumulating ability of the tested species and evaluate their capacity to reflect environmental availability. Neither the sequences in the shell nor those in the tissues were similar to the sequence in the water. The differences between the sequences of the mussel tissues and those of the sediments were less striking than those between shells and sediments. Similar results were obtained by macrophytes. In conclusion, the results of this study (which mimics the monitoring practice prove that bioaccumulators cannot be used to evaluate the

Temperature-dependent toxicity of artemisinin toward the macrophyte Lemna minor and the algae Pseudokirchneriella subcapitata

DEFF Research Database (Denmark)

Jessing, Karina Knudsmark; Andresen, Marianne; Cedergreen, Nina

2014-01-01

- and groundwater. To make better risk assessments of A. annua which is cultivated under varying climatic conditions, the temperature-dependent toxicity of artemisinin toward the green algae Pseudokirchneriella subcapitata and the macrophyte Lemna minor was evaluated at temperatures ranging from 10 to 30°C....... To include a possible effect of temperature on the degradation rate of artemisinin, artemisinin concentrations were measured during the experiment and toxicity was related to the time-weighted averages of exposure concentrations. The toxicity of artemisinin toward the macrophyte L. minor and the algae P....... subcapitata increased with increasing growth rates, and we conclude that bioavailability plays a minor role in the observed relation between temperature and toxicity of artemisinin. The obtained results are important for possible future risk assessment of A. annua cultivation....

Remote sensing of macrophyte morphological traits: Implications for the management of shallow lakes

Directory of Open Access Journals (Sweden)

Paolo Villa

2017-03-01

Full Text Available Macrophytes are important elements of freshwater ecosystems, fulfilling a pivotal role in biogeochemical cycles. The synoptic capabilities provided by remote sensing make it a powerful tool for monitoring aquatic vegetation characteristics and the functional status of shallow lake systems in which they occur. The latest generation of airborne and spaceborne imaging sensors can be effectively exploited for mapping morphologically – and physiologically – relevant vegetation features based on their canopy spectral response. The objectives of this study were to calibrate semi-empirical models for mapping macrophyte morphological traits (i.e., fractional cover, leaf area index and above-water biomass from hyperspectral data, and to investigate the capabilities of remote sensing in supporting macrophyte monitoring and management. We calibrated spectral models using in situ reflectance and morphological trait measures and applied them to airborne hyperspectral imaging data, acquired over two shallow European water bodies (Lake Hídvégi, in Hungary, and Mantua lakes system, in Italy in two key phenological phases. Maps of morphological traits were produced covering a broad range of aquatic plant types (submerged, floating, and emergent, common to temperate and continental regions, with an error level of 5.4% for fractional cover, 0.10 m2 m-2 for leaf area index, and 0.06 kg m-2 for above-water biomass. Based on these maps, we discuss how remote sensing could support monitoring strategies and shallow lake management with reference to our two case studies: i.e., by providing insight into spatial and species-wise variability, by assessing nutrient uptake by aquatic plants, and by identifying hotspot areas where invasive species could become a threat to ecosystem functioning and service provision.

The Use of Aquatic Macrophyte Ecotoxicological Assays in Monitoring Coastal Effluent Discharges in Southern Australia

Energy Technology Data Exchange (ETDEWEB)

Burridge, T.R.; Karistianos, M.; Bidwell, J

1999-01-01

Germination inhibition of zoospores of the aquatic, brown algal macrophyte Ecklonia radiata was employed to assess the toxicity of sewage effluents under short to long term exposure and under modified salinity conditions. The rate of germination inhibition was determined for exposure times between 2 and 48 h in salinity modified and unmodified regimes and under reduced salinity conditions alone. The results indicated that rate of germination inhibition increased with duration of exposure to sewage effluents and to salinity reduction alone, and that response to the effluents may be enhanced under conditions of reduced salinity. Whilst the effect of primary treated effluent was primarily that of toxicity, secondary treated effluent effects appeared to be primarily that of reduced salinity although at a greater rate than would be expected for salinity reduction alone. The assay is suggested to provide a mechanism for monitoring sewage effluent quality and to monitor potential impacts of sewage effluent discharge on kelp communities in southern Australia.

The Use of Aquatic Macrophyte Ecotoxicological Assays in Monitoring Coastal Effluent Discharges in Southern Australia

International Nuclear Information System (INIS)

Burridge, T.R.; Karistianos, M.; Bidwell, J.

1999-01-01

Germination inhibition of zoospores of the aquatic, brown algal macrophyte Ecklonia radiata was employed to assess the toxicity of sewage effluents under short to long term exposure and under modified salinity conditions. The rate of germination inhibition was determined for exposure times between 2 and 48 h in salinity modified and unmodified regimes and under reduced salinity conditions alone. The results indicated that rate of germination inhibition increased with duration of exposure to sewage effluents and to salinity reduction alone, and that response to the effluents may be enhanced under conditions of reduced salinity. Whilst the effect of primary treated effluent was primarily that of toxicity, secondary treated effluent effects appeared to be primarily that of reduced salinity although at a greater rate than would be expected for salinity reduction alone. The assay is suggested to provide a mechanism for monitoring sewage effluent quality and to monitor potential impacts of sewage effluent discharge on kelp communities in southern Australia

Invertebrate herbivory on floating-leaf macrophytes at the northeast of Argentina: should the damage be taken into account in estimations of plant biomass?

Science.gov (United States)

Martínez, Fedra S; Franceschini, Celeste

2018-01-01

We assessed the damage produced by invertebrate herbivores per leaf lamina and per m2 of populations floating-leaf macrophytes of Neotropical wetlands in the growth and decay periods, and assessed if the damage produced by the herbivores should be taken into account in the estimations of plant biomass of these macrophytes or not. The biomass removed per lamina and per m2 was higher during the growth period than in decay period in Nymphoides indica and Hydrocleys nymphoides, while Nymphaea prolifera had low values of herbivory in growth period. During decay period this plant is only present as vegetative propagules. According to the values of biomass removed per m2 of N. indica, underestimation up to 17.69% should be produced in cases that herbivory do not should be taking account to evaluate these plant parameters on this macrophyte. Therefore, for the study of biomass and productivity in the study area, we suggest the use of corrected lamina biomass after estimating the biomass removed by herbivores on N. indica. The values of damage in N. indica emphasize the importance of this macrophyte as a food resource for invertebrate herbivores in the trophic networks of the Neotropical wetlands.

The effects of cadmium pulse dosing on physiological traits and growth of the submerged macrophyte Vallisneria spinulosa and phytoplankton biomass: a mesocosm study.

Science.gov (United States)

Liu, Hui; Cao, Yu; Li, Wei; Zhang, Zhao; Jeppesen, Erik; Wang, Wei

2017-06-01

Pulse inputs of heavy metals are expected to increase with a higher frequency of extreme climate events (heavy rain), leading to stronger erosion of contaminated and fertilized farmland soils to freshwaters, with potentially adverse effects on lake ecosystems. We conducted a 5-month mesocosm study to elucidate the responses of the submerged macrophyte Vallisneria spinulosa and phytoplankton to four different doses of cadmium (Cd): 0 (control), 0.05, 0.5, and 5 g m -2 (CK, I, II, and III, respectively) under mesotrophic conditions. We found that total phosphorus concentrations were larger in the three Cd pulse treatments, whereas total nitrogen concentrations did not differ among the four treatments. The contents of chlorophyll a and soluble sugar in macrophyte leaves decreased in III, and total biomass, ramet number, plant height, and total stolon length of macrophytes were lower in both II and III. In contrast, abundances of the three main phytoplankton taxa-Cyanophyta, Chlorophyta, and Bacillariophyta-did not differ among treatments. Total phytoplankton biomass was, however, marginally lower in CK than in the Cd treatments. We conclude that exposure to strong Cd pulses led to significantly reduced growth of macrophytes, while no obvious effect appeared for phytoplankton.

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.

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.

Effects of dissolved organic matter leaching from macrophyte litter on black water events in shallow lakes.

Science.gov (United States)

He, Yuhong; Song, Na; Jiang, He-Long

2018-04-01

In recent years, the black water phenomenon has become an environmental event in eutrophic shallow lakes in China, leading to deterioration of lake ecosystems and potable water crises. Decomposition of macrophyte debris has been verified as a key inducement for black water events. In this study, the effects of the decomposition of dissolved organic matter (Kottelat et al., WASP 187:343-351, 2008) derived from macrophyte leachate on the occurrence of black water events are investigated to clarify the detailed mechanisms involved. Results show that dissolved organic matter (DOM) is composed of a trace of chromophoric DOM and mostly non-chromophoric dissolved organic matter (CDOM). DOM decomposition is accompanied by varied concentration of CDOM components, generation of organic particles, and increased microbial concentrations. These processes increase water chroma only during initial 48 h, so the intensified water color cannot be maintained by DOM decomposition alone. During DOM decomposition, microorganisms first consume non-CDOM, increasing the relative CDOM concentration and turning the water color to black (or brown). Simultaneously, tryptophan and aromatic proteins, which are major ingredients of CDOM, enhance UV light absorption, further aggravating the macroscopic phenomenon of black color. Our results show that DOM leached from decayed macrophytes promotes or even triggers the occurrence of black water events and should be taken more seriously in the future.

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....... 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...

Removal of nutrients and veterinary antibiotics from swine wastewater by a constructed macrophyte floating bed system.

Science.gov (United States)

Xian, Qiming; Hu, Lixia; Chen, Hancheng; Chang, Zhizhou; Zou, Huixian

2010-12-01

The potential of three varieties of Italian ryegrass (Lolium multiflorum Lam.), Dryan, Tachimasari and Waseyutaka, to improve the water quality of swine wastewater was evaluated using a constructed macrophyte floating bed system. With respect to reductions in levels of nutrients, chemical oxygen demand (COD), and sulfonamide antimicrobials (SAs, including sulfadiazine, sulfamethazine, and sulfamethoxazole), Dryan performed better than Tachimasari and Waseyutaka. For Dryan, total N was reduced by 84.0%, total P by 90.4%, COD by 83.4% and sulfonamide antimicrobials by 91.8-99.5%. Similar results were observed for Tachimasari and Waseyutaka. The results indicated that the treatment of swine wastewater using the constructed macrophyte floating bed system was effective in the removal of nutrients and veterinary antibiotics. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

The cross-ecosystem impact of deer on an endangered submerged macrophyte, Ranunculus nipponicus var. submersus

Directory of Open Access Journals (Sweden)

Hino Takafumi

2015-07-01

Full Text Available Macrophytes are a critical component of freshwater ecosystems and are often eaten by cervids. However, the impact of cervids on macrophytes is not well known. In this study, we investigated the effect of sika deer (Cervus nippon yesoensis on the endangered macrophyte Ranunculus nipponicus var. submersus in a spring stream in southwestern Hokkaido, Japan. We monitored the frequency of stream habitat use by deer by using sensor cameras in photography mode for four seasons. We also monitored deer feeding behavior on R. nipponicus var. submersus using sensor cameras in movie mode. To quantitatively evaluate the impact of deer on R. nipponicus var. submersus, we conducted a field experiment in which deer were excluded from part of the stream. We selected 10 pairs of adjacent patches of R. nipponicus var. submersus and set up exclosures covering one patch in each pair. We assessed the frequency of deer feeding and trampling on the control patches using the sensor cameras in photography mode and measured the mean macrophyte stem length in the exclosure and control patches every month for four seasons. To compare abiotic conditions between the exclosure and control patches, we investigated canopy openness, water depth, water temperature, electrical conductivity, pH, current velocity, and water quality at each patch during the growing season. The frequency of deer in the stream habitat was higher from spring to summer than in other seasons. Direct evidence of deer feeding behavior on R. nipponicus var. submersus was recorded using the sensor cameras. Deer often fed on and trampled on the control patches, particularly from spring to summer. The R. nipponicus var. submersus stem length was longer in the exclosure patches than in control patches (P 0.189. Stem growth of R. nipponicus var. submersus differed among seasons (P <0.001, and was low from winter to spring. In addition, exclosure and seasonality significantly affected stem length (P <0.001, and the

Using linoleic acid embedded cellulose acetate membranes to in situ monitor polycyclic aromatic hydrocarbons in lakes and predict their bioavailability to submerged macrophytes.

Science.gov (United States)

Tao, Yuqiang; Xue, Bin; Yao, Shuchun

2015-05-19

To date no passive sampler has been used to predict bioavailability of contaminants to macrophytes. Here a novel passive sampler, linoleic acid embedded cellulose acetate membrane (LAECAM), was developed and used to in situ measure the freely dissolved concentrations of ten polycyclic aromatic hydrocarbons in the sediment porewaters and the water columns of two lakes in both winter and summer and predict their bioavailability to the shoots of resident submerged macrophytes (Potamogeton malainus, Myriophyllum spicata, Najas minor All., and Vallisneria natans (Lour.) Hara). PAH sampling by LAECAMs could reach equilibrium within 21 days. The influence of temperature on LAECAM-water partition coefficients was 0.0008-0.0116 log units/°C. The method of LAECAM was comparable with the active sampling methods of liquid-liquid extraction combined with fDOC adjustment, centrifugation/solid-phase extraction (SPE), and filtration/SPE but had several advantages. After lipid normalization, concentrations of the PAHs in LAECAMs were not significantly different from those in the macrophytes. In contrast, concentrations of the PAHs in the triolein containing passive sampler (TECAM) deployed simultaneously with LAECAM were much higher. The results suggest that linoleic acid is more suitable than triolein as the model lipid for passive samplers to predict bioavailability of PAHs to submerged macrophytes.

Evaluation of the feeding preference between the aquatic macrophytes Egeria densa and Chara indica by the invasive mollusk Melanoides tuberculata.

Science.gov (United States)

Medeiros, E L; Henry-Silva, G G

2017-01-01

This study evaluated the feeding preference of the invasive mollusk Melaniudes tuberculata between the aquatic macrophytes Egeria densa and Chara indica. The experiment consisted of twelve experimental units (glass aquariums) each of which contained three liters of water and three compartments. Fragments of E. densa and C. indica were placed in separate compartments within each unit; the third compartment, which did not contain macrophytes, was used as the control. Twenty Melanoides tuberculata individuals were placed in each unit and monitored hourly over the course of 24 hours for preferential movements. Physical and chemical water variables were measured at the beginning and end of the experiment. Habitat complexity was determined through collected macrophyte fragments and determined using the Fractop program. After 24 hours, the highest average number of individuals was observed in the treatment with Chara indica (ten individuals), which differed significantly from the treatment with E. densa (four individuals) and the control treatment (two individuals). The number of individuals between the E. densa and control treatment were similar. M. tuberculata showed a clear feeding preference for C. indica.

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.

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

Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

Science.gov (United States)

Yam, Rita S. W.; Fan, Yen-Tzu; Wang, Tzu-Ting

2016-01-01

Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents. PMID:26927135

Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

Directory of Open Access Journals (Sweden)

Rita S. W. Yam

2016-02-01

Full Text Available Pomacea canaliculata (Ampullariidae has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.

Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands.

Science.gov (United States)

Yam, Rita S W; Fan, Yen-Tzu; Wang, Tzu-Ting

2016-02-24

Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.

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 ( 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. 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 .

Temperature dependence of UV radiation effects in Arctic and temperate isolates of three red macrophytes

NARCIS (Netherlands)

van de Poll, W.H.; Eggert, A.; Buma, A.G.J.; Breeman, Arno

The temperature dependence of UV effects was studied for Arctic and temperate isolates of the red macrophytes Palmaria palmata, Coccotylus truncatus and Phycodrys rubens. The effects of daily repeated artificial ultraviolet B and A radiation (UVBR: 280-320 nm, UVAR: 320-400 nm) treatments were

Effect of lighting conditions of coastal zone of Knyaginya lake on composition of macrophyte biohydrocenoses

Directory of Open Access Journals (Sweden)

B. O. Baranovsky

2005-10-01

Full Text Available In articlе the stuffs of researches of influence of a mode of illuminating intensity of coastal zone of a different exposition flood-land of lake Knyaginya (valley Samara on composition of highest aqueous green and macrozoobentos macrophytes biogeocenose are submitted.

Effects of contrasting omnivorous fish on submerged macrophyte biomass in temperate lakes: a mesocosm experiment

NARCIS (Netherlands)

Dorenbosch, M.; Bakker, E.S.

2012-01-01

1.Freshwater fish can affect aquatic vegetation directly by consuming macrophytes or indirectly by changing water quality. However, most fish in the temperate climate zone have an omnivorous diet. The impact of fish as aquatic herbivores in temperate climates therefore remains unclear and depends on

Arsenic levels in the soils and macrophytes of the 'Entremuros' after the Aznalcollar mine spill

Energy Technology Data Exchange (ETDEWEB)

Taggart, M.A. [Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, Aberdeen AB24 3UU (United Kingdom)]. E-mail: mark.taggart@abdn.ac.uk; Carlisle, M. [Department of Geography and Environment, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Pain, D.J. [RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL (United Kingdom); Williams, R. [RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL (United Kingdom); Green, D. [Department of Geography and Environment, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Osborn, D. [Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS (United Kingdom); Meharg, A.A. [Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, Aberdeen AB24 3UU (United Kingdom)

2005-01-01

In April 1998, a holding lagoon containing pyrite ore processing waste rich in arsenic, failed and released 5-6 million m{sup 3} of highly polluting sludge and acidic water. Over 2700 ha of the internationally important Don-tilde ana National and Natural Parks were contaminated. The area of Natural Park to sustain the greatest impact was known as the Entremuros. This paper presents 0-5 cm soil monitoring data from the Entremuros, from sampling campaigns 6 and 18 months after the disaster; as well as macrophyte root, rhizome and stem data from samples taken 18 months after the spill. Results show a clear, decreasing, north-south arsenic soil pollution trend, both 6 and 18 months after the spill, and suggest a small reduction in total soil arsenic levels occurred over time; although a significant increase in extractable arsenic is also noted. The two macrophytes (Typha dominguensis and Scirpus maritimus) studied herein are not accumulating arsenic in stem parts, however, accumulation of arsenic on iron plaque on the roots of these plants may be occurring. Further work is recommended in order to determine the ecotoxicological significance of this process in relation to the avian food-chains of Don-tilde ana, and elsewhere. - Capsule: Arsenic associated with iron plaque on macrophyte roots may pose an ecotoxicological risk to certain herbivores.

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

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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

2016-01-01

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/OCH 3 and COO/N–C=O increasing, which may be owing to the insoluble compounds including C functional groups of alkyl-C, NCH/OCH 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 13 C NMR and solution 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.

Root biomass production in populations of six rooted macrophytes in response to Cu exposure: intra-specific variability versus constitutive-like tolerance.

Science.gov (United States)

Marchand, L; Nsanganwimana, F; Lamy, J B; Quintela-Sabaris, C; Gonnelli, C; Colzi, I; Fletcher, T; Oustrière, N; Kolbas, A; Kidd, P; Bordas, F; Newell, P; Alvarenga, P; Deletic, A; Mench, M

2014-10-01

Intra-specific variability of root biomass production (RP) of six rooted macrophytes, i.e. Juncus effusus, Phragmites australis, Schoenoplectus lacustris, Typha latifolia, Phalaris arundinacea, and Iris pseudacorus grown from clones, in response to Cu exposure was investigated. Root biomass production varied widely for all these macrophytes in control conditions (0.08 μM) according to the sampling site. Root biomass production of T. latifolia and I. pseudacorus in the 2.5-25 μM Cu range depended on the sampling location but not on the Cu dose in the growth medium. For P. australis, J. effusus, S. lacustris, and P. arundinacea, an intra-specific variability of RP depending on both the sampling location and the Cu-dose was evidenced. This intra-specific variability of RP depending on the sampling location and of Cu-tolerance for these last four species suggests that Cu constitutive tolerance for all rooted macrophytes is not a species-wide trait but it exhibits variability for some species. Copyright © 2014 Elsevier Ltd. All rights reserved.

Importance of groundwater and macrophytes for the nutrient balance at oligotrophic Lake Hampen, Denmark

DEFF Research Database (Denmark)

Ommen, Daniela Oliveira; Kidmose, Jacob Baarstrøm; Karan, Sachin

2012-01-01

input). The majority of the nitrogen is leached from the agricultural fields bordering the lake. Concentrations as high as 1750 µM nitrate were measured in the rhizosphere of the littoral zone at this location. It is estimated that the macrophytes are able to take up 1695 kg N yr-1 (~50 % of the input...

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

Kinetics of extracellular release of 14C-labelled organic carbon by submerged macrophytes

International Nuclear Information System (INIS)

Soendergaard, M.

1981-01-01

The release of extracellular organic carbon (EOC) by six submerged freswater macrophytes was measured in time course studies with a 14 C-technique. Incubation in light in an open water-flow system made it possible to assay the time courses of 14 C-fixation and the simultaneous release of labelled EOC. Heterotrophic utilization of the released products by epiphytic communities was measured. Two patterns of release kinetics were found: (1) Constant rates of release occurred during the incubations, (2) The rates still increased after 24 h of incubation. During the first hours of incubation the rates of release increased in all species. Elodea reached constant rates after 2-4 h and Littorella and Ceratophyllum demersum after about 20 h. In the experiments with C. submersum and Nitella the rates of release increased almost linearly during the entire incubation period. The kinetics of release were in agreement with the molecular weight distribution of the dissolved EOC measured with gel chromatography. Low molecular weight products ( 10000 Daltons) dominated the dissolved EOC released by C. submersum and Nitella. A large fraction (18-60%) of the total EOC could be recovered on filters with a pore size of 0.2 μm. This particulate fraction probably represents some abiotic removal. The quantities of relase were low in all species and did not exceed 0.9% of the photosynthetic carbon fixation. Heterotrophic uptake by the epiphytic communities was less than 10% of the EOC released. The results emphasize that the 14 C-labelling of extracellular products is a time dependent process. (author)

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.

Poster power brings together electronics community

CERN Multimedia

2006-01-01

An 'Electronics at CERN' poster session was displayed on the mezzanine in building 500 for two days from 30 November. The display consisted of 20 posters and brought together a wide range of electronic projects designed and assembled by CERN teams and other collaborators involved in the building of the LHC. This was the first time this event had been held. As its organiser John Evans (IT/DES) explained, 'the idea came from the experience of attending conferences outside CERN, where you may find projects from CERN you didn't know about. It's nice to bring them together so we can all benefit from the efforts made.' The work on show spanned different departments and experiments, ranging from microelectronics to equipment designed for giant magnets. The invited audience was equally broad and included engineers, physicists as well as the electronics community at CERN. An informal gathering of all the exhibitors also offered an opportunity to view and discuss the work over a cup of coffee. 'The poster session acts...

Ecological responses of epilithic diatoms and aquatic macrophytes to fish farm pollution in a Spanish river

Directory of Open Access Journals (Sweden)

Camargo, Julio A.

2007-12-01

Full Text Available We examined the ecological responses of epilithic diatoms and aquatic macrophytes to organic pollution and nutrient enrichment caused by a trout farm effluent in the upper Tajuña River (Guadalajara, Spain. Four sampling sites were selected over the study area: one site (S-1 placed upstream from the trout farm was used as a reference station; sampling sites S-2, S-3 and S-4 were set, respectively, about 10, 100 and 1000 metres downriver of the trout farm outlet. The river bottom was mainly stony with cobbles and pebbles at S-1, S-3 and S-4, but at S-2 it was covered by a thick layer of organic sediment. Although some macrophyte species (Apium nodiflorum, Groenlandia densa were either absent or fewer downstream of the farm, abundance (% coverage and diversity (number of species for the aquatic macrophyte community as a whole increased. In contrast, epilithic diatoms were completely absent at S-2, and some species (Diploneis parma, Fragilaria ulna, Gomphonema angustatum, Nitzschia dissipata were also absent at S-3 and S-4. Indeed, diatom diversity (number of species was lower at S-3 and S-4 than at S-1. However, diatom abundance (cells/cm2 was higher at S-3 and S-4 than at S-1. Biological indices for diatoms (IBD, TDI indicated a better water quality at S-1 than at S-3 and S-4, with a clear tendency to improve with distance from the fish farm. In contrast, biological indices of macrophytes (IM, IVAMG indicated a similar water quality at S-1, S-3 and S-4, but with bad water quality at S-2. We conclude that epilithic diatoms may be more useful than aquatic macrophytes for biological monitoring of fish farm pollution in fluvial ecosystems. However, as historical and seasonal factors may be relevant to understanding the distribution, abundance and diversity of primary producers in running waters, further studies on long-term seasonal changes are needed to improve the use of macrophyte and diatom indices in assessing fish farm pollution.En este trabajo

Macrophytes control on a stretch of the Ebro River flowing through the Asco Nuclear Power Plant

International Nuclear Information System (INIS)

Munte Clua, L.; Fernandez Alentorn, E.; Beltran Grau, A.

2010-01-01

The objective of this paper is to evaluate the time evolution of the different macrophytes populations in the stretch of the Ebro River between the town of Flix and the Asco Nuclear Power Plant, and the effects observed by the programmed flood for their control.

Macrobenthos of Vembanad estuary in relation to the deposition of degraded water fern Salvinia and other macrophytes

Digital Repository Service at National Institute of Oceanography (India)

Gopalan, U.K.; Meenakshikunjamma, P.P.; Vengayil, D.T.

Composition and seasonal abundance of macrobenthos in Vembanad estuary (India) seems to be influenced by the density of decaying macrophytes, especially the water fern Salvinia , deposited at the bottom of the estuary at the rate of 356.76 g/m super...

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

Science.gov (United States)

1989-11-01

seagrass ) and reported that it quickly colonized with algae and invertebrates that were on live plants. Rooke (1986) found considerable dif- ferences...al. (1982) observed that seagrass (Zostera marina) reduced current velocities inside the plant bed, but current velocities were actually higher over...hard-water lakes (Mickle and Wetzel 1978a, 1978b, 1979). Diurnal changes in photosynthesis rates within the boundary layer of macrophyte beds can cause a

Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry

OpenAIRE

Ieromina, O.; Musters, C. J. M.; Bodegom, P. M.; Peijnenburg, W. J. G. M.; Vijver, M. G.

2016-01-01

Analyzing functional species? characteristics (species traits) that represent physiological, life history and morphological characteristics of species help understanding the impacts of various stressors on aquatic communities at field conditions. This research aimed to study the combined effects of pesticides and other environmental factors (temperature, dissolved oxygen, dissolved organic carbon, floating macrophytes cover, phosphate, nitrite, and nitrate) on the trait modality distribution ...

Using Multispectral Sentinel-2 Data to Monitor Submerse Macrophytes

Science.gov (United States)

Wolf, Patrick; Roessler, Sebastian; Schneider, Thomas; Melzer, Arnulf

2012-04-01

Due to climate change and the involved temperatures of Bavarian freshwater lakes, the invasive submerse macrophytes Elodea nuttallii and Najas marina exhibit a massive expansion. To map these processes, a monitoring system based on remote sensing methods is under development. The main part of the monitoring system is a coupled reflection-/growth-model, which derives biometrical parameters for the EU water framework directive (WFD) by inversion of the reflectance spectra. For operational monitoring tasks a high revisiting time is necessary. Hence, the Sentinel-2 sensor might be very promising, as filling the gap between RapidEye and WorldView2 and between hyperspectral an aerial images. This paper outlines principles, methods and first results of the project.

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.

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.

Simulated bioavailability of phosphorus from aquatic macrophytes and hytoplankton by aqueous suspension and incubation with alkaline phosphatase

Science.gov (United States)

Bioavailability of phosphorus (P) in aquatic macrophytes and algae on lake eutrophication was studied by evaluation their P forms and quantities in their water suspensions and impact by alkaline phosphatase hydrolysis. using solution 31P-nuclear magnetic resonance (NMR). The laboratory suspension an...

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.

Macrophyte presence is an indicator of enhanced denitrification and nitrification in sediments of a temperate restored agricultural stream

Science.gov (United States)

Stream macrophytes are often removed with their sediments to deepen stream channels, stabilize channel banks, or provide habitat for target species. These sediments may support enhanced nitrogen processing. To evaluate sediment nitrogen processing, identify seasonal patterns, and...

Response of littoral macrophytes to water level fluctuations in a storage reservoir

Czech Academy of Sciences Publication Activity Database

Krolová, Monika; Čížková, Hana; Hejzlar, Josef; Poláková, S.

2013-01-01

Roč. 408, May (2013), 07p1-07p21 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GA206/09/1764; GA MŠk(CZ) 7E11059 Grant - others:EC ENV(CZ) FP7 244121 Program:FP7 Institutional research plan: CEZ:AV0Z60170517 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : littoral macrophytes * eulittoral * water level fluctuation * European Water Framework Directive * ecophases Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.622, year: 2013

Effect of Elodea nuttallii roots on bacterial communities and MMHg proportion in a Hg polluted sediment.

Science.gov (United States)

Regier, Nicole; Frey, Beat; Converse, Brandon; Roden, Eric; Grosse-Honebrink, Alexander; Bravo, Andrea Garcia; Cosio, Claudia

2012-01-01

The objective of this study was to assess the effect of a rooted macrophyte Elodea nuttallii on rhizosphere bacterial communities in Hg contaminated sediments. Specimens of E. nuttallii were exposed to sediments from the Hg contaminated Babeni reservoir (Olt River, Romania) in our microcosm. Plants were allowed to grow for two months until they occupied the entirety of the sediments. Total Hg and MMHg were analysed in sediments where an increased MMHg percentage of the total Hg in pore water of rhizosphere sediments was found. E. nuttallii roots also significantly changed the bacterial community structure in rhizosphere sediments compared to bulk sediments. Deltaproteobacteria dominated the rhizosphere bacterial community where members of Geobacteraceae within the Desulfuromonadales and Desulfobacteraceae were identified. Two bacterial operational taxonomic units (OTUs) which were phylogenetically related to sulfate-reducing bacteria (SRB) became abundant in the rhizosphere. We suggest that these phylotypes could be potentially methylating bacteria and might be responsible for the higher MMHg percentage of the total Hg in rhizosphere sediments. However, SRB were not significantly favoured in rhizosphere sediments as shown by qPCR. Our findings support the hypothesis that rooted macrophytes created a microenvironment favorable for Hg methylation. The presence of E. nuttallii in Hg contaminated sediments should therefore not be overlooked.

Effect of Elodea nuttallii roots on bacterial communities and MMHg proportion in a Hg polluted sediment.

Directory of Open Access Journals (Sweden)

Nicole Regier

Full Text Available The objective of this study was to assess the effect of a rooted macrophyte Elodea nuttallii on rhizosphere bacterial communities in Hg contaminated sediments. Specimens of E. nuttallii were exposed to sediments from the Hg contaminated Babeni reservoir (Olt River, Romania in our microcosm. Plants were allowed to grow for two months until they occupied the entirety of the sediments. Total Hg and MMHg were analysed in sediments where an increased MMHg percentage of the total Hg in pore water of rhizosphere sediments was found. E. nuttallii roots also significantly changed the bacterial community structure in rhizosphere sediments compared to bulk sediments. Deltaproteobacteria dominated the rhizosphere bacterial community where members of Geobacteraceae within the Desulfuromonadales and Desulfobacteraceae were identified. Two bacterial operational taxonomic units (OTUs which were phylogenetically related to sulfate-reducing bacteria (SRB became abundant in the rhizosphere. We suggest that these phylotypes could be potentially methylating bacteria and might be responsible for the higher MMHg percentage of the total Hg in rhizosphere sediments. However, SRB were not significantly favoured in rhizosphere sediments as shown by qPCR. Our findings support the hypothesis that rooted macrophytes created a microenvironment favorable for Hg methylation. The presence of E. nuttallii in Hg contaminated sediments should therefore not be overlooked.

Trade-off between drag reduction and light interception of macrophytes: comparing five aquatic plants with contrasting morphology

NARCIS (Netherlands)

Bal, K.D.; Bouma, T.J.; Buis, K.; Struyf, E.; Jonas, S.; Backx, H.; Meire, P.

2011-01-01

1. Macrophytes in running waters experience an often dynamic and harsh environment. To avoid breakage, plants have to reduce the experienced drag force. However, by reducing leaf area, photosynthetic production is less. Aquatic plants therefore have to find a balance between reducing drag and

Quantification of the impact of macrophytes on oxygen dynamics and nitrogen retention in a vegetated lowland river

NARCIS (Netherlands)

Desmet, N.J.S.; Van Belleghem, S.; Seuntjens, P.; Bouma, T.J.; Buis, K.; Meire, P.

2011-01-01

When macrophytes are growing in the river, the vegetation induces substantial changes to the water quality. Some effects are the result of direct interactions, such as photosynthetic activity or nutrient uptake, whereas others may be attributed to indirect effects of the water plants on

Growth of common brackish marsh macrophytes under altered hydrology and salinity regimes

Science.gov (United States)

Howard, Rebecca J.; Biagas, Janelda M.; Allain, Larry K.

2016-01-01

Coastal marsh plants are increasingly subject to physicochemical stressors under rising sea levels, and the maintenance of marsh ecological functions can depend on the ability of individual species and communities to tolerate or adapt to altered conditions. We conducted a greenhouse experiment to identify hydrology and salinity effects on growth of three common brackish marsh macrophytes of coastal Florida, USA: Distichlis spicata, Juncus roemerianus, and Spartina bakeri. The species were potted as monocultures and exposed to three salinities (0, 15, or 28 psu) and two hydrologic conditions (saturated, tidal) over 22 months. Final stem density of J. roemerianus and S. bakeri did not differ among treatments. In D. spicata, however, stem density was lowest at 28 psu and lower in tidal compared to saturated conditions. Mean stem height of all species was lowest at 28 psu. Aboveground biomass of J. roemerianus was not affected by the treatments, but in D. spicata andS. bakeri it was lowest at 28 psu. Results indicated that J. roemerianus was the most adaptable species and may, therefore, be more resilient to climate-change driven stressors. However, plant-plant interactions such as interspecific competition and facilitation can alter the response of individual species to environmental factors.

The influence of permanently submerged macrophytes on sediment mercury distribution, mobility and methylation potential in a brackish Norwegian fjord.

Science.gov (United States)

Olsen, Marianne; Schaanning, Morten Thorne; Braaten, Hans Fredrik Veiteberg; Eek, Espen; Moy, Frithjof E; Lydersen, Espen

2018-01-01

Macrophytes are shown to affect the microbial activity in different aqueous environments, with an altering of the sediment cycling of mercury (Hg) as a potential effect. Here, we investigated how a meadow with permanently submerged macrophytes in a contaminated brackish fjord in southern Norway influenced the conditions for sulfate reducing microbial activity, the methyl-Hg (MeHg) production and the availability of MeHg. Historically discharged Hg from a chlor-alkali plant (60-80tons, 1947-1987) was evident through high Hg concentrations (491mgTot-Hgkg -1 , 268μgMeHgkg -1 ) in intermediate sediment depths (10-20cm) outside of the meadow, with reduced concentrations within the meadow. Natural recovery of the fjord was revealed by lower sediment surface concentrations (1.9-15.5mgTot-Hgkg -1 , 1.3-3.2μgMeHgkg -1 ). Within the meadow, vertical gradients of sediment hydrogen sulfide (H 2 S) E h and pH suggested microbial sulfate reduction in 2-5cm depths, coinciding with peak values of relative MeHg levels (0.5% MeHg). We assume that MeHg production rates was stimulated by the supply and availability of organic carbon, microbial activity and a sulfide oxidizing agent (e.g. O 2 ) within the rhizosphere. Following this, % MeHg in sediment (0-5cm) within the meadow was approximately 10× higher compared to outside the meadow. Further, enhanced availability of MeHg within the meadow was demonstrated by significantly higher fluxes (p<0.01) from sediment to overlying water (0.1-0.6ngm -2 d -1 ) compared to sediment without macrophytes (0.02-0.2ngm -2 d -1 ). Considering the productivity and species richness typical for such habitats, submerged macrophyte meadows located within legacy Hg contaminated sediment sites may constitute important entry points for MeHg into food webs. Copyright © 2017 Elsevier B.V. All rights reserved.

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

DEFF Research Database (Denmark)

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

2016-01-01

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

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)

Electronic Communities: a Forum for Supporting Women Professionals and Students in Technical and Scientific Fields

Science.gov (United States)

Single, Peg Boyle; Muller, Carol B.; Cunningham, Christine M.; Single, Richard M.

In this article, we report on electronic discussion lists (e-lists) sponsored by MentorNet, the National Electronic Industrial Mentoring Network for Women in Engineering and Science. Using the Internet, the MentorNet program connects students in engineering and science with mentors working in industry. These e-lists are a feature of MentorNet's larger electronic mentoring program and were sponsored to foster the establishment of community among women engineering and science students and men and women professionals in those fields. This research supports the hypothesis that electronic communications can be used to develop community among engineering and science students and professionals and identifies factors influencing the emergence of electronic communities (e-communities). The e-lists that emerged into self-sustaining e-communities were focused on topic-based themes, such as balancing personal and work life, issues pertaining to women in engineering and science, and job searching. These e-communities were perceived to be safe places, embraced a diversity of opinions and experiences, and sanctioned personal and meaningful postings on the part of the participants. The e-communities maintained three to four simultaneous threaded discussions and were sustained by professionals who served as facilitators by seeding the e-lists with discussion topics. The e-lists were sponsored to provide women students participating in MentorNet with access to groups of technical and scientific professionals. In addition to providing benefits to the students, the e-lists also provided the professionals with opportunities to engage in peer mentoring with other, mostly female, technical and scientific professionals. We discuss the implications of our findings for developing e-communities and for serving the needs of women in technical and scientific fields.

The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

Directory of Open Access Journals (Sweden)

Cíntia Karen Bulla

2011-06-01

Full Text Available We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size. In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.Nesse trabalho as assembleias de peixes associadas a bancos de macrófitas flutuantes à deriva foram descritas. Além disso, foi considerado o possível papel desses bancos como vetores de dispersão no rio Ivinhema, importante tributário do alto rio Paraná, Brasil. Os peixes associados aos bancos à deriva foram amostrados no canal principal desse rio, entre os meses de Janeiro a Março de 2005, quando o vento e/ou o aumento no nível da água foram suficientes para transportar os bancos de macrófitas. Os peixes foram amostrados com uma rede flutuante (4 m de comprimento x 2 m de largura x 0,6 m de altura e 2 mm de tamanho de malha. No

Floating macrophytes on the wastewater treatment: a state of the art review Macrófitas flotantes en el tratamiento de aguas residuales: una revisión del estado del arte

Directory of Open Access Journals (Sweden)

Jorge Martelo

2012-06-01

Full Text Available The wastewater treatments with floating macrophytes have proven effective in the remediation of waters with nutrient content, organic matter and toxic substances such as arsenic, zinc, cadmium, copper, lead, chromium, and mercury. Its importance lies in its ability to be used in rural communities due to their low consumption of conventional energy and practicality in the assembly and operation of treatment systems. Still, it has not been clarified thoroughly the processes taking place in the purification of wastewater with floating macrophytes. This article attempts to review the existing literature on floating macrophytes, thus identifying the general aspects, advantages and disadvantages of using these plants for treating wastewater. Similarly, identify the most important background since the beginning of this application. There will be described models and design criteria mostly employed, rigorously reviewing removal efficiencies of different species of floating macrophytes. Finally it will be addressed as discussed current perspectives and future challenges for the development of this technique.Los tratamientos de aguas residuales que involucran macrófitas flotantes han demostrado ser eficientes en la remediación de aguas con contenidos de nutrientes, materia orgánica y sustancias toxicas como arsénico, zinc, cadmio, cobre, plomo, cromo, y mercurio. Su importancia radica en su aptitud para ser empleados en núcleos rurales debido a su bajo consumo de energía convencional y la practicidad en el montaje y operación de los sistemas de tratamiento. Aun así, todavía no se han esclarecido rigurosamente los procesos que tienen lugar en la depuración de aguas residuales con macrófitas flotantes. El presente artículo pretende hacer un recorrido por la literatura existente sobre macrófitas flotantes, identificando los aspectos generales, ventajas y desventajas del uso de estas plantas para depurar aguas residuales. De igual manera

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...

Field assessment of oxytetracycline exposure to the freshwater macrophytes Egeria densa Planch. and Ceratophyllum demersum L

International Nuclear Information System (INIS)

Hanson, M.L.; Knapp, C.W.; Graham, D.W.

2006-01-01

In a microcosm study, two aquatic macrophytes, Egeria densa and Ceratophyllum demersum were exposed to nominal concentrations of 0, 5, 20, 50, and 250 μg/L oxytetracycline (n = 3), plus 20 μg/L oxytetracycline amended with additional nitrogen (N) and phosphorus (P). Responses were monitored bi-weekly over a six-week exposure period. Both plant species exhibited a significant decline in growth in the 250 μg/L oxytetracycline and the N- and P-amended units. Decreased light penetration resulting from accumulating oxytetracycline by-products appears to be the primary modifier in the growth of these plants. Increased susceptibility to oxytetracycline exposure was noted in some paired plantings (e.g., E. densa root development), relative to individual plants in these treatments, however, no clear explanation for this response is available. Based on the toxicity data generated in this study, we estimate that current concentrations of oxytetracycline in freshwater environments do not pose a direct risk to E. densa and C. demersum. - Oxytetracycline did not pose a risk for two freshwater macrophytes

Field assessment of oxytetracycline exposure to the freshwater macrophytes Egeria densa Planch. and Ceratophyllum demersum L

Energy Technology Data Exchange (ETDEWEB)

Hanson, M L [Department of Environment and Geography, University of Manitoba, 118 Isbister Building, Winnipeg, Manitoba R3T 2N2 (Canada); Knapp, C W [Department of Civil, Environmental, and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States); Graham, D W [Department of Civil, Environmental, and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States)

2006-06-15

In a microcosm study, two aquatic macrophytes, Egeria densa and Ceratophyllum demersum were exposed to nominal concentrations of 0, 5, 20, 50, and 250 {mu}g/L oxytetracycline (n = 3), plus 20 {mu}g/L oxytetracycline amended with additional nitrogen (N) and phosphorus (P). Responses were monitored bi-weekly over a six-week exposure period. Both plant species exhibited a significant decline in growth in the 250 {mu}g/L oxytetracycline and the N- and P-amended units. Decreased light penetration resulting from accumulating oxytetracycline by-products appears to be the primary modifier in the growth of these plants. Increased susceptibility to oxytetracycline exposure was noted in some paired plantings (e.g., E. densa root development), relative to individual plants in these treatments, however, no clear explanation for this response is available. Based on the toxicity data generated in this study, we estimate that current concentrations of oxytetracycline in freshwater environments do not pose a direct risk to E. densa and C. demersum. - Oxytetracycline did not pose a risk for two freshwater macrophytes.

Polluting macrophytes Colombian lake Fúquene used as substrate by edible fungus Pleurotus ostreatus.

Science.gov (United States)

Martínez-Nieto, Patricia; García-Gómez, Gustavo; Mora-Ortiz, Laura; Robles-Camargo, George

2014-01-01

Invasive aquatic plants from Lake Fúquene (Cundinamarca, Colombia), water hyacinth (Eichhornia crassipes C. Mart.) and Brazilian elodea (Egeria densa Planch.) have been removed mechanically from the lake and can be used for edible mushrooms production. The growth of the oyster mushroom (Pleurotus ostreatus) on these aquatic macrophytes was investigated in order to evaluate the possible use of fruiting bodies and spent biomass in food production for human and animal nutrition, respectively. Treatments included: water hyacinth, Brazilian elodea, sawdust, rice hulls and their combinations, inoculated with P. ostreatus at 3%. Water hyacinth mixed with sawdust stimulated significantly fruiting bodies production (P = 3.3 × 10(-7)) with 71% biological efficacy, followed by water hyacinth with rice husk (55%) and elodea with rice husk (48%), all of these have protein contents between 26 and 47%. Loss of lignin (0.9-21.6%), cellulose (3.7-58.3%) and hemicellulose (1.9-53.8%) and increment in vitro digestibility (16.7-139.3%) and reducing sugars (73.4-838.4%) were observed in most treatments. Treatments spent biomass presented Relative Forage Values (RFV) from 46.1 to 232.4%. The results demonstrated the fungus degrading ability and its potential use in aquatic macrophytes conversion biomass into digestible ruminant feed as added value to the fruiting bodies production for human nutrition.

Oxidative stress responses of submerged macrophyte Vallisneria asiatica to different concentrations of cyanobacteria

Science.gov (United States)

Kang, Caixia; Kuba, Takahiro; Hao, Aimin; Iseri, Yasushi; Li, Chunjie; Zhang, Zhenjia

2015-03-01

In a 10-day aquarium experiment, this investigation examines macrophyte restoration in eutrophic Lake Taihu, the physiological effects of different plant biomass levels and of increasing natural cyanobacterial concentrations on a submerged macrophyte, Vallisneria asiatica. Cyanobacterial stress suppressed the superoxide dismutase (SOD) activity of the plant's leaves and induced the catalase (CAT) and peroxidase (POD) activities of its roots. The soluble protein content in V. asiatica decreased with an increase in natural cyanobacterial concentrations, whereas the malonaldehyde (MDA) increased significantly at chlorophyll a (Chl a) concentrations of 222 and 262 μg/L in water. V. asiatica adapted to the stress caused by cyanobacterial concentrations by adjusting its antioxidant defense system to remove the excessive reactive oxygen species when the algal Chl a concentration was >109 μg/L. Additionally, high biomass of V. asiatica (2 222 g FW/m2) can inhibit the reproduction of cyanobacteria more significantly than low biomass (1 111 g FW/m2). High biomass of V. asiatica increased the oxidative stress in an individual plant when the initial Chl a concentration in the water reached 222 and 262 μg/L, as expressed by the increased MDA in leaves, compared with low biomass of V. asiatica. This provides a basis for controlling cyanobacterial concentrations and V. asiatica biomass for the recovery of V. asiatica in eutrophic Lake Taihu.

Electronic Cigarette using in Surabaya’s Personal Vaporizer Community

Directory of Open Access Journals (Sweden)

Apsari Damayanti

2017-02-01

Full Text Available Electronic cigarette is devices capable of delivering nicotine in an aerosolized form. The number of electronic cigarette users is increasing. Data showed an Indonesia electronic cigarette user in 2010 to 2011 is 0,5%. This research was observasional decriptive study and used cross sectional design. This research was conducted to 31 Surabaya’s Personal Vaporizer members. The dependent variable in this study was electronic cigarette using, while independent variable were the knowledge, accessibility and family factor. Data were analyzed by prevalens ratio. The result showed that using of electronic cigarette mostly suffered by respondent age 26 to 35 years old was equal to 54,8%, male (96,8% and educational level was senior high school to university (100%, occupation was employee (71%, had a smoking history (93,6%, and using electronic cigarette for smoking cessation (80,6%. The analyzed with prevalens ratio showed that right knowlegde about electronic cigarette was a protective factor to being using electronic cigarette (PR=0,89, accessibility ≤ Rp 100.000 was a risk to being using electronic cigarette, and family was a protective factor to being using electronic cigarette (PR=0,95. From all variable which were studied, only accessibility that a risk factor with electronic cigarette using. Therefore, education about electronic cigarette haved to do and controlling toward electronic cigarette user needed to do.   Keywords : electronic cigarette, accessibility, community, knowledge, behavior

Why NASA and the Space Electronics Community Cares About Cyclotrons

Science.gov (United States)

LaBel, Kenneth A.

2017-01-01

NASA and the space community are faced with the harsh reality of operating electronic systems in the space radiation environment. Systems need to work reliably (as expected for as long as expected) and be available during critical operations such as docking or firing a thruster. This talk will provide a snapshot of the import of ground-based research on the radiation performance of electronics. Discussion topics include: 1) The space radiation environment hazard, 2) Radiation effects on electronics, 3) Simulation of effects with cyclotrons (and other sources), 4) Risk prediction for space missions, and, 5) Real-life examples of both ground-based testing and space-based anomalies and electronics performance. The talk will conclude with a discussion of the current state of radiation facilities in North America for ground-based electronics testing.

Spatio-temporal distribution of Diaphanosoma brachyurum (Cladocera: Sididae in freshwater reservoir ecosystems: importance of maximum water depth and macrophyte beds for avoidance of fish predation

Directory of Open Access Journals (Sweden)

Jong-Yun Choi

2014-10-01

Full Text Available In empirical studies, Cladocera is commonly utilized as a primary food source for predators such as fish, thus, predator avoidance are important strategies to sustain their population in freshwater ecosystems. In this study, we tested the hypothesis that water depth is an important factor in determining the spatial distribution of Diaphanosoma brachyurum Liévin, 1848 in response to fish predation. Quarterly monitoring was implemented at three water layers (i.e., water surface and middle and bottom layers in 21 reservoirs located in the southeastern part of South Korea. D. brachyurum individuals were frequently observed at the study sites and exhibited different spatial patterns of distribution in accordance with the maximum depth of the reservoirs. In the reservoirs with a maximum depth of more than 6 m, high densities of D. brachyurum were observed in the bottom layers; however, in the shallower reservoirs (maximum depth <6 m, D. brachyurum were concentrated in the surface layer. Moreover, during additional surveys, we observed a trend in which D. brachyurum densities increased as the maximum depth or macrophyte biomass increased. Gut contents analysis revealed that predatory fishes in each reservoir frequently consumed D. brachyurum; however, the consumption rate abruptly decreased in reservoirs where the maximum depth was more than 11 m or in the shallow reservoirs supporting a macrophyte bed. Interestingly, the reservoirs more than 11-m depth supported high densities of D. brachyurum in the bottom layer and in the surface macrophyte bed. Based on these results, reservoirs with a maximum depth of more than 11 m or those with a macrophyte bed may provide a refuge for D. brachyurum to avoid fish predation. Compared with other cladoceran species, D. brachyurum readily exploits various types of refugia (in this study, the deep layer or surface macrophyte bed, which may help explain why this species is abundant in various types of reservoirs.

Effect of lead toxicity on aquatic macrophyte Elodea canadensis Michx.

Science.gov (United States)

Dogan, Muhittin; Saygideger, Saadet Demirors; Colak, Ugur

2009-08-01

Effects of Pb accumulation on the contents of chlorophylls (a and b), carotenoid, ascorbic acid (AsA), non-protein SH groups and protein were investigated in aquatic macrophyte Elodea canadensis. Pb accumulation in E. canadensis tissues increased with increasing metal concentrations. The increases at 1, 10 and 100 mg/L Pb are about 12.0, 44.6 and 71.1 times greater than control, respectively. Contents of chlorophylls, carotenoid and protein were adversely affected by Pb accumulation. Induction of non-protein SH groups and AsA showed that Pb accumulation caused oxidative stress. It is also possible that increased non-protein SH groups by Pb accumulation may be due to their role in Pb detoxification.

Progressive recovery of a tropical deforested stream community after a flash flood

Directory of Open Access Journals (Sweden)

Lucas Cerqueira Marques

2013-06-01

Full Text Available AIM: In this study, we evaluated and compared community attributes from a tropical deforested stream, located in a pasture area, in a period before (PRED I and three times after (POSD I, II, and III a flash flood, in order to investigate the existence of temporal modifications in community structure that suggests return to conditions previous to the flash flood. METHODS: Biota samples included algae, macrophytes, macroinvertebrates, and fish assemblages. Changes in stream physical structure we also evaluated. Similarity of the aquatic biota between pre and post-disturbance periods was examined by exploratory ordination, known as Non-Metric Multidimensional Scaling associated with Cluster Analysis, using quantitative and presence/absence Bray-Curtis similarity coefficients. Presence and absence data were used for multivariate correlation analysis (Relate Analysis in order to investigate taxonomic composition similarity of biota between pre and post-disturbance periods. RESULTS: Our results evidenced channel simplification and an expressive decrease in richness and abundance of all taxa right after the flood, followed by subsequent increases of these parameters in the next three samples, indicating trends towards stream community recovery. Bray-Curtis similarity coefficients evidenced a greater community structure disparity among the period right after the flood and the subsequent ones. Multivariate correlation analysis evidenced a greater correlation between macroinvertebrates and algae/macrophytes, demonstrating the narrow relation between their recolonization dynamics. CONCLUSIONS: Despite overall community structure tended to return to previous conditions, recolonization after the flood was much slower than that reported in literature. Finally, the remarkably high flood impact along with the slow recolonization could be a result of the historical presence of anthropic impacts in the region, such as siltation, riparian forest complete depletion

[Effects of two submerged macrophytes on dissolved inorganic nitrogen in overlying water and interstitial water].

Science.gov (United States)

Yang, Wen-Bin; Li, Yang; Sun, Gong-Xian

2014-06-01

Ceratophyllum demersum (C. demersum) and Vallisneria spiralis L. (V. spiralis L.) were studied as model submerged macrophytes. The effects of the submerged macrophytes on the forms and concentration of the dissolved inorganic nitrogen (DIN) in the overlying water and the interstitial water, as well as the diffusion flux of DIN in the water-sediment interface were investigated by batch simulation experiment. The results indicated that the removal effect of DIN in the overlying water was better than that in the interstitial water by submerged macrophytes. The removal efficiency of DIN in the overlying water and the interstitial water followed the order of NO2(-) -N > NH4(+) -N > NO3(-) -N. The removal rate of DIN by C. demersum was higher than that of V. spiralis L. in the overlying water, while the result was converse in the interstitial water. C. demersum and V. spiralis L. decreased the diffusion flux of NH4(+) -N and NO2(-) -N, and increased the diffusion flux of NO3(-) -N significantly. Consequently, NO3(-) -N replaced NH4(+) -N and became the main form of DIN, which diffused from the interstitial water to the overlying water. The impact of the diffusion flux of NO3(-) -N between C. demersum and V. spiralis L. showed no significant difference, and the result was the same for NH4(+) -N. C. demersum and V. spiralis L. increased the width of variation of the three nitrogen forms to total DIN in the overlying water and the interstitial water, the influence on the ratio of DIN by C. demersum was greater than that of V. spiralis L. in the overlying water, while the result was opposite in the interstitial water. In general, C. demersum had more influence in the overlying water, while V. spiralis L. had more influence in the interstitial water, and the influence of DIN diffusion flux was not significant.

Growth Control of Cyanobacteria by Three Submerged Macrophytes

Science.gov (United States)

Wang, Haiou; Zhong, Guangrong; Yan, Hai; Liu, Hu; Wang, Yao; Zhang, Chun

2012-01-01

Abstract To illustrate the control of harmful cyanobacterial growth and the removal of nutritients from fresh water, three submerged macrophytes were grown in the raw water of Guishui Lake. Lindernia rotundifolia, Hygrophila stricta, and Cryptocoryne crispatula were grown together in situ to assess their effectiveness in nutrient removal in microcosms. Results revealed the inhibitory effects of these species on cyanobacterial growth. In addition, water quality in the planted microcosms showed improvement when compared to the water quality of the unplanted microcosm. At all treatments studied, the chemical oxygen demand in the planted microcosms was lower than that in the unplanted microcosms, and the removal rate of all the nitrogen and phosphate in the planted microcosms was better than that of the microcosm without plants. Our study offers a useful algal control method for the lakes or reservoirs that suffer from harmful cyanobacterial blooms. PMID:22693412

異なる酸素条件下で沈水植物（コカナダモ、エビモ）の生長、栄養塩吸収およびいくつかの生化学的パラメータに対するアンモニウムイオン濃度の影響について

OpenAIRE

TANJEENA, ZAMAN

2013-01-01

Submerged macrophytes are important functional and structural elements of aquatic ecosystems, and fulfill several important functions in these systems. They can be regarded as key species; changes in the macrophyte community can have major consequences for the aquatic ecosystems. Many different types of submerged aquatic macrophytes have been identified globally. Most submerged aquatic macrophytes belong to the families Ceratophyllaceae, Haloragaceae, Hydrocharitaceae, Nymphaeaceae and Potam...

pH gradients in the diffusive boundary layer of subarctic macrophytes

KAUST Repository

Hendriks, Iris E.; Duarte, Carlos M.; Marbà , Nú ria; Krause-Jensen, Dorte

2017-01-01

Highly productive macrophytes produce diurnal and seasonal cycles in CO concentrations modulated by metabolic activity, which cause discrepancies between pH in the bulk water and near seaweed blades, especially when entering the diffusion boundary layer (DBL). Calcifying epiphytic organisms living in this environment are therefore exposed to a different pH environment than that of the water column. To evaluate the actual pH environment on blade surfaces, we measured the thickness of the DBL and pH gradients within it for six subarctic macrophytes: Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, Zostera marina, Saccharina longicruris, and Agarum clathratum. We measured pH under laboratory conditions at ambient temperatures (2–3 °C) and slow, stable flow over the blade surface at five light intensities (dark, 30, 50, 100 and 200 µmol photons m s). Boundary layer thickness ranged between 511 and 1632 µm, while the maximum difference in pH (∆pH) between the blade surface and the water column ranged between 0.4 ± 0.14 (average ± SE; Zostera) and 1.2 ± 0.13 (average ± SE; Ulva) pH units. These differences in pH are larger than predictions for pH changes in the bulk water by the end of the century. A simple quadratic model best described the relationship between light intensity and maximum ∆pH, pointing at relatively low optimum PAR of between 28 and 139 µmol photons m s to reach maximum ∆pH. Elevated pH at the blade surface may provide chemical “refugia” for calcifying epiphytic organisms, especially during summer at higher latitudes where photoperiods are long.

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.

pH gradients in the diffusive boundary layer of subarctic macrophytes

KAUST Repository

Hendriks, Iris E.

2017-06-20

Highly productive macrophytes produce diurnal and seasonal cycles in CO concentrations modulated by metabolic activity, which cause discrepancies between pH in the bulk water and near seaweed blades, especially when entering the diffusion boundary layer (DBL). Calcifying epiphytic organisms living in this environment are therefore exposed to a different pH environment than that of the water column. To evaluate the actual pH environment on blade surfaces, we measured the thickness of the DBL and pH gradients within it for six subarctic macrophytes: Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, Zostera marina, Saccharina longicruris, and Agarum clathratum. We measured pH under laboratory conditions at ambient temperatures (2–3 °C) and slow, stable flow over the blade surface at five light intensities (dark, 30, 50, 100 and 200 µmol photons m s). Boundary layer thickness ranged between 511 and 1632 µm, while the maximum difference in pH (∆pH) between the blade surface and the water column ranged between 0.4 ± 0.14 (average ± SE; Zostera) and 1.2 ± 0.13 (average ± SE; Ulva) pH units. These differences in pH are larger than predictions for pH changes in the bulk water by the end of the century. A simple quadratic model best described the relationship between light intensity and maximum ∆pH, pointing at relatively low optimum PAR of between 28 and 139 µmol photons m s to reach maximum ∆pH. Elevated pH at the blade surface may provide chemical “refugia” for calcifying epiphytic organisms, especially during summer at higher latitudes where photoperiods are long.

Increasing phytoplankton-available phosphorus and inhibition of macrophyte on phytoplankton bloom.

Science.gov (United States)

Dai, Yanran; Wu, Juan; Ma, Xiaohang; Zhong, Fei; Cui, Naxin; Cheng, Shuiping

2017-02-01

We assembled mesocosms to address the coherent mechanisms that an increasing phosphorus (P) concentration in water columns coupled with the phytoplankton bloom and identify the performance gap of regulating phytoplankton growth between two macrophyte species, Ceratophyllum demersum L. and Vallisneria spiralis L. Intense alkaline phosphatase activities (APA) were observed in the unplanted control, with their predominant part, phytoplankton APA (accounting for up to 44.7% of the total APA), and another large share, bacterial APA. These correspond with the large average concentration of total phosphorus (TP), total dissolved phosphorus (TDP) and soluble reactive (SRP) as well as high phytoplankton density in the water column. The consistency among P concentrations, phytoplankton density and APA, together with the positive impact of phytoplankton density on total APA revealed by the structural equation modelling (SEM), indicates that facilitated APA levels in water is an essential strategy for phytoplankton to enhance the available P. Furthermore, a positive interaction between phytoplankton APA and bacteria APA was detected, suggesting a potential collaboration between phytoplankton and bacteria to boost available P content in the water column. Both macrophyte species had a prominent performance on regulating phytoplankton proliferation. The phytoplankton density and quantum yield in C. demersum systems were all significantly lower (33.8% and 24.0%) than those in V. spiralis systems. Additionally, a greater decoupling effect of C. demersum on the relationship between P, APA, phytoplankton density, bacteria dynamic and quantum yield was revealed by SEM. These results imply that the preferred tactic of different species could lead to the performance gap. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

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...

Uptake and elimination kinetics of perfluoroalkyl substances in submerged and free-floating aquatic macrophytes: Results of mesocosm experiments with Echinodorus horemanii and Eichhornia crassipes.

Science.gov (United States)

Pi, N; Ng, J Z; Kelly, B C

2017-06-15

Studies investigating the bioaccumulation behavior of perfluoroalkyl substances (PFASs) in aquatic macrophytes are limited. The present study involved controlled mesocosm experiments to assess uptake and elimination rate constants (k u, k e ), bioconcentration factors (BCFs) and translocation factors (TFs) of several perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) in two aquatic plant species, including one submerged species (Echinodorus horemanii) and one free-floating species (Eichhornia crassipes). The results indicated all PFASs were readily accumulated in these aquatic macrophytes. k u and BCFs increased with increasing perfluoroalkyl chain length. For PFCAs and PFSAs with identical perfluoroalkyl chain length, the corresponding PFSA exhibited higher bioaccumulation potential. On a whole-plant basis, the bioaccumulation potential of PFASs in submerged and free-floating macrophytes were comparable, indicating sorption to plant biomass is similar in the different species. Conversely, when considering accumulation in foliage, BCFs in the free-floating macrophyte were substantially lower compared to submerged species, especially for longer-chain PFASs. Compounds with shorter perfluoroalkyl chain length (PFBS, PFPeA and PFHxA) exhibited preferential translocation to leaf tissue (TFs >1). BCFs exhibited a sigmoidal relationship with pefluoroalkyl chain length, membrane-water distribution coefficients (D mw ), protein-water distribution coefficients (D pw ) and organic-water partition coefficients (K oc ). For these trends, maximum BCF values were exhibited by long-chain PFCAs, with a log D mw , log D pw and log K oc of 6.47, 5.72 and 5.04, respectively. These findings are useful for future design and implementation of phytoremediation systems, as well for future develop of mechanistic models for predicting the environmental fate and distribution of these contaminants of concern. Copyright © 2017. Published by Elsevier Ltd.

Pilot Trial of an Electronic Family Medical History in US Faith-Based Communities.

Science.gov (United States)

Newcomb, Patricia; Canclini, Sharon; Cauble, Denise; Raudonis, Barbara; Golden, Paulette

2014-07-01

In spite of the acknowledged importance of collecting family health information, methods of collecting, organizing, and storage of pedigree data are not uniformly utilized in practice, though several electronic tools have been developed for the purpose. Using electronic tools to gather health information may empower individuals to take responsibility in managing their family health history. The purpose of this study was to describe the feasibility and outcomes of introducing small groups to the My Family Health Portrait tool in faith-based communities using faith community nurses (FCNs). This pilot project adopted a mixed methods approach to assess the potential of an educational intervention delivered by FCNs for increasing the use of electronic technologies for organizing and storing family health histories among the general public. Treatment and control groups were recruited from four faith-based communities in north Texas using a parallel-groups quasi-experimental design. Qualitative data were gleaned from field notes made by investigators interacting with FCNs and observing their teaching. A majority of respondents believed that knowing one's health history and passing it on to family and medical personnel is important. Those receiving face-to-face instruction on the electronic tool were significantly more likely to have written down family health information than the control group who received only an informational handout (χ(2) = 5.96, P = .015). Barriers to teaching about and using the electronic tool included FCNs' lack of facility with computers in the educational context and FCN and respondent mistrust of electronic storage for family health information. © The Author(s) 2014.

Use of native aquatic macrophytes in the reduction of organic matter from dairy effluents.

Science.gov (United States)

Queiroz, Rita de Cássia Souza de; Andrade, Rodrigo Santos; Dantas, Isadora Rosário; Ribeiro, Vinícius de Souza; Neto, Luciano Brito Rodrigues; Almeida Neto, José Adolfo de

2017-08-03

Considering the diversity and the unexplored potential of regional aquatic flora, this study aimed to identify and analyze the potential of native aquatic macrophytes to reduce the organic matter of dairy wastewater (DW) using experimental constructed wetlands. The dairy wastewater (DW) had an average chemical oxygen demand (COD) of 7414.63 mg/L and then was diluted to 3133.16 mg/L (D1) and to 2506.53 mg/L (D2). Total solids, COD, temperature, and pH analyses were performed, and the biochemical oxygen demand (BOD) was estimated from the COD values. The best performance in the reduction of the organic matter was observed for Polygonum sp. (87.5% COD and 79.6% BOD) and Eichhornia paniculata (90% COD and 83.7% BOD) at dilution D1, on the 8th day of the experiment. However, the highest total solids removal was observed for Polygonum sp. (32.2%), on the 4th day, at dilution D2. The total solid (TS) concentration has also increased starting from the 8th day of the experiment was observed which may have been due to the development of mosquito larvae and their mechanical removal by sieving, thus changing the steady state of the experimental systems. The macrophytes Polygonum sp. and E. paniculata were considered suitable for the reduction of organic matter of DW using constructed wetlands.

Coexistence of fish species in a large lowland river: food niche partitioning between small-sized percids, cyprinids and sticklebacks in submersed macrophytes.

Science.gov (United States)

Dukowska, Małgorzata; Grzybkowska, Maria

2014-01-01

In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes. Chironomidae dominated in the diet of the percids. However, ruffe consumed mostly benthic chironomids, while perch epiphytic chironomids and zooplankton. The diet of dace resembled that in fast flowing water although this rheophilic species occurred at unusual density there. The generalist roach displayed the lowest gut fullness coefficient values and widest niche breadth; consequently, intraspecific rather than interspecific competition decided the fate of roach. Three-spined stickleback differed from the other fishes by consuming epiphytic simuliids and fish eggs. The diet overlap between fishes reaching higher gut fullness coefficient values was rather low when the food associated with the submersed aquatic macrophytes was most abundant; this is congruent with the niche overlap hypothesis that maximal tolerable niche overlap can be higher in less intensely competitive conditions.

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.

Community-based blood pressure measurement by non-health workers using electronic devices: a validation study

OpenAIRE

Daniel D. Reidpath; Mei Lee Ling; Shajahan Yasin; Kanason Rajagobal; Pascale Allotey

2012-01-01

Introduction: Population monitoring and screening of blood pressure is an important part of any population health strategy. Qualified health workers are expensive and often unavailable for screening. Non-health workers with electronic blood pressure monitors are increasingly used in community-based research. This approach is unvalidated. In a poor, urban community we compared blood pressure measurements taken by non-health workers using electronic devices against qualified health workers usin...

Implementing an electronic hand hygiene monitoring system: Lessons learned from community hospitals.

Science.gov (United States)

Edmisten, Catherine; Hall, Charles; Kernizan, Lorna; Korwek, Kimberly; Preston, Aaron; Rhoades, Evan; Shah, Shalin; Spight, Lori; Stradi, Silvia; Wellman, Sonia; Zygadlo, Scott

2017-08-01

Measuring and providing feedback about hand hygiene (HH) compliance is a complicated process. Electronic HH monitoring systems have been proposed as a possible solution; however, there is little information available about how to successfully implement and maintain these systems for maximum benefit in community hospitals. An electronic HH monitoring system was implemented in 3 community hospitals by teams at each facility with support from the system vendor. Compliance rates were measured by the electronic monitoring system. The implementation challenges, solutions, and drivers of success were monitored within each facility. The electronic HH monitoring systems tracked on average more than 220,000 compliant HH events per facility per month, with an average monthly compliance rate >85%. The sharing of best practices between facilities was valuable in addressing challenges encountered during implementation and maintaining a high rate of use. Drivers of success included a collaborative environment, leadership commitment, using data to drive improvement, consistent and constant messaging, staff empowerment, and patient involvement. Realizing the full benefit of investments in electronic HH monitoring systems requires careful consideration of implementation strategies, planning for ongoing support and maintenance, and presenting data in a meaningful way to empower and inspire staff. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Stable nitrogen isotope ratios of macrophytes and associated periphyton along a nitrate gradient in two subtropical, spring-fed streams

DEFF Research Database (Denmark)

De Brabandere, Loreto; Frazer, Thomas K.; Montoya, Joseph P.

2007-01-01

, macrophytes and periphyton as a consequence of isotopic fractionation associated with preferential use of 14NO3-. This hypothesis was tested in two spring-fed river systems, the Chassahowitzka and Homosassa rivers, along Florida’s central Gulf of Mexico coast. 3. In general, d15N values of nitrate...

Accumulation and effects of copper on aquatic macrophytes Potamogeton pectinatus L.: Potential application to environmental monitoring and phytoremediation.

Science.gov (United States)

Costa, Marcela Brandão; Tavares, Francesca Valêncio; Martinez, Claudia Bueno; Colares, Ioni Gonçalves; Martins, Camila de Martinez Gaspar

2018-07-15

This study investigated the ability of Potamogeton pectinatus L. to accumulate copper and its effects on plants. In accumulation tests, macrophytes were exposed (96 h) to different copper concentrations (0-1000 µM) and the metal was measured in media and plant tissues (roots, stems and leaves) to determine the bioconcentration factor (BCF). Plants accumulated high concentrations of copper in a dose-dependent manner and roots was the main organ for copper accumulation. However, the more copper increased in water, the more BCF values decreased. It may be due to either saturation of copper uptake or down-regulation of metal uptake by plants. In the physiological and morphological analyses, plants were kept (96 h) in Hoagland nutrient solution without copper, in full Hoagland solution (0.5 µM Cu) and in Hoagland medium with copper from 1 to 100 µM. The absence and the presence of copper above to 1 µM inhibited photosynthesis. Chlorophylls and carotenoid levels also decreased with the excess of copper, a fact that may have affected the photosystem II-dependent of chlorophyll and caused photosynthesis suppression. Only macrophytes at 10 µM Cu showed decrease in length and number of leaves on the 10th day of the test, when they died. Chlorosis and necrosis were observed in control groups and groups with extra copper, but not in Hoalgand group. Overall, the macrophyte P. pectinatus can be considered a suitable plant for monitoring environments contaminated by copper, based on results of copper accumulation in the plant, decrease in pigment concentration and presence of chlorosis and necrosis. However, values of BCF based on fresh water tissues was not proper to indicate the use of P. pectinatus for cleaning environments contaminated by copper. Copyright © 2018 Elsevier Inc. All rights reserved.

Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat

Directory of Open Access Journals (Sweden)

Jerome eBabauta

2014-01-01

Full Text Available Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode with tip size ~20 µm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.

Localized electron transfer rates and microelectrode-based enrichment of microbial communities within a phototrophic microbial mat.

Science.gov (United States)

Babauta, Jerome T; Atci, Erhan; Ha, Phuc T; Lindemann, Stephen R; Ewing, Timothy; Call, Douglas R; Fredrickson, James K; Beyenal, Haluk

2014-01-01

Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH, and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 μm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode at depth in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.

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 ...

Bar-coded pyrosequencing reveals the responses of PBDE-degrading microbial communities to electron donor amendments.

Directory of Open Access Journals (Sweden)

Meiying Xu

Full Text Available Polybrominated diphenyl ethers (PBDEs can be reductively degraded by microorganisms under anaerobic conditions. However, little is known about the effect of electron donors on microbial communities involved in PBDEs degradation. Here we employed 454 Titanium pyrosequencing to examine the phylogenetic diversity, composition, structure and dynamics of microbial communities from microcosms under the conditions of different electron donor amendments. The community structures in each of the five alternate electron donor enrichments were significantly shifted in comparison with those of the control microcosm. Commonly existing OTUs between the treatment and control consortia increased from 5 to 17 and more than 50% of OTUs increased around 13.7 to 186 times at least in one of the microcosms after 90-days enrichment. Although the microbial communities at different taxonomic levels were significantly changed by different environmental variable groups in redundancy analysis, significant correlations were observed between the microbial communities and PBDE congener profiles. The lesser-brominated PBDE congeners, tri-BDE congener (BDE-32 and hexa-BDE, were identified as the key factors shaping the microbial community structures at OTU level. Some rare populations, including the known dechlorinating bacterium, Dehalobacter, showed significant positive-correlation with the amounts of PBDE congeners in the consortia. The same results were also observed on some unclassified bacteria. These results suggest that PBDEs-degrading microbial communities can be successfully enriched, and their structures and compositions can be manipulated through adjusting the environmental parameters.

Flow Management to Control Excessive Growth of Macrophytes - An Assessment Based on Habitat Suitability Modeling.

Science.gov (United States)

Ochs, Konstantin; Rivaes, Rui P; Ferreira, Teresa; Egger, Gregory

2018-01-01

Mediterranean rivers in intensive agricultural watersheds usually display outgrowths of macrophytes - notably alien species - due to a combination of high concentrations of nutrients in the water runoff and low flows resulting from water abstraction for irrigation. Standard mechanical and chemical control is used to mitigate the problems associated with excessive growth of plant biomass: mainly less drainage capacity and higher flood risk. However, such control measures are cost and labor-intensive and do not present long-term efficiency. Although the high sensitivity of aquatic vegetation to instream hydraulic conditions is well known, management approaches based on flow management remain relatively unexplored. The aim of our study was therefore to apply physical habitat simulation techniques promoted by the Instream Flow Incremental Method (IFIM) to aquatic macrophytes - the first time it has been applied in this context - in order to model shifts in habitat suitability under different flow scenarios in the Sorraia river in central Portugal. We used this approach to test whether the risk of invasion and channel encroachment by nuisance species can be controlled by setting minimum annual flows. We used 960 randomly distributed survey points to analyze the habitat suitability for the most important aquatic species (including the invasive Brazilian milfoil Myriophyllum aquaticum , Sparganium erectum , and Potamogeton crispus ) in regard to the physical parameters 'flow velocity,' 'water depth,' and 'substrate size'. We chose the lowest discharge period of the year in order to assess the hydraulic conditions while disturbances were at a low-point, thus allowing aquatic vegetation establishment and subsistence. We then used the two-dimensional hydraulic River2D software to model the potential habitat availability for different flow conditions based on the site-specific habitat suitability index for each physical parameter and species. Our results show that the growth

Sediment denitrification and nitrification is enhanced by the presence of macrophytes in a restored agricultural stream, Black Earth Creek, WI USA

Science.gov (United States)

Restoration of habitats that support microbial processing can enhance nitrate removal in agricultural streams. Macrophytes are common both in-stream and in the wetted fringe of agricultural stream systems, but are often removed in restoration to increase stream velocity or stabil...

Decreasing but still significant facilitation effect of cold-season macrophytes on wetlands purification function during cold winter.

Science.gov (United States)

Zou, Xiangxu; Zhang, Hui; Zuo, Jie; Wang, Penghe; Zhao, Dehua; An, Shuqing

2016-06-01

To identify the facilitation effect of a cool-season aquatic macrophyte (FEam) for use in effluent purification via constructed floating wetlands (CFWs) and to determine the possible pathways used during a winter period with an average temperature of less than 5 °C, pilot-scale CFWs were planted with the cold-season macrophyte Oenanthe clecumbens and were operated as batch systems. Although some leaves withered, the roots retained relatively high levels of activity during the winter, which had average air and water temperatures of 3.63 and 5.04 °C, respectively. The N and P removal efficiencies in CFWs decreased significantly in winter relative to those in late autumn. The presence of cool-season plants resulted in significant improvements in N and P removal, with a FEam of 15.23-25.86% in winter. Microbial N removal accounted for 71.57% of the total N removed in winter, and the decrease in plant uptake was the dominant factor in the wintertime decrease in N removal relative to that in late autumn. These results demonstrate the importance of cold-season plants in CFWs for the treatment of secondary effluent during cold winters.

Influence of a carp invasion on the zooplankton community in Laguna Medina, a Mediterranean shallow lake

OpenAIRE

Norbert, Florian; López-Luque, raquel; Ospina-Álvarez, Natalia; Hufnagel, Levente; Green, Andy J.

2016-01-01

The common carp (Cyprinus carpio) is a highly invasive species and an ecological engineer. It has been repeatedly shown to increase nutrient concentrations and phytoplankton biomass while destroying submerged macrophytes, although there are few studies from the Mediterranean region. We studied its impact on the zooplankton community in Laguna de Medina lake, a shallow lake in Jerez de la Frontera, south-west Spain. Carp were removed with rotenone in 2007 but returned in 2010-2011. ...

Effects of dredging and macrophyte management on the fish species composition in an old Neotropical reservoir

Directory of Open Access Journals (Sweden)

André Luiz Henríques Esguícero

2017-03-01

Full Text Available Abstract: Aim: As part of the remodeling of an almost century-old dam, in the Rio Jacaré-Guaçu, the dredging and management of macrophytes were carried out in the Gavião Peixoto Reservoir (São Paulo State, Brazil. Data for the reservoir and a river stretch upstream the reservoir were compared, for evaluating the effects of the management procedures. Methods The fish fauna and physical and chemical factors were studied during five years, before (2005-2006 and after the recovery procedures (2007-2009, once a year, during the rainy season. Fishes were caught by gill nets, 10 m long and 1.5, 4, and 6 cm-mesh between adjacent knots. Results After the management procedures, the values of pH and dissolved oxygen increased in the reservoir, whereas conductivity decreased, bringing them closer to those of the upstream stretch. Species richness, diversity, and Catch per Unit Effort in number and biomass, increased in the reservoir after the management. Conclusions After the recovery procedures, the composition of the fish fauna in the reservoir was similar to that of the upstream stretch. The dredging and management of macrophytes in the reservoir benefited the fish fauna diversity, through improvement in water quality and space expansion.

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.

TraLaLa Blip: Community Music for the Electronically Abled

Science.gov (United States)

Reimann, Randolf

2012-01-01

This article presents a personal reflection on the use of electronic music as a vehicle for community music in a disability setting. In order to do this, I draw on my experiences as the founder, facilitator, producer, tutor, sound artist and musician of TraLaLa Blip. I established the group in 2008, after having worked with people with…

Mass development of monospecific submerged macrophyte vegetation after the restoration of shallow lakes: roles of light, sediment nutrient levels, and propagule density

NARCIS (Netherlands)

Verhofstad, M.J.J.M.; Alirangues, Marta Maria; Reichman, Erik; van Donk, E.; Lamers, L.P.M.; Bakker, E.S.

2017-01-01

Abstract After restoration, eutrophicated shallow freshwaters may show mass development of only one or two submerged macrophyte species, lowering biodiversity and hampering recreation. It is unclear which environmental factors govern this high percentage of the volume inhabited (PVI11 PVI: The

Mass development of monospecific submerged macrophyte vegetation after the restoration of shallow lakes: Roles of light, sediment nutrient levels, and propagule density

NARCIS (Netherlands)

Verhofstad, M.J.J.M.; Alirangues Núñez, M. M.; Reichman, E. P.; van Donk, E.; Lamers, L. P.M.; Bakker, E. S.

2017-01-01

After restoration, eutrophicated shallow freshwaters may show mass development of only one or two submerged macrophyte species, lowering biodiversity and hampering recreation. It is unclear which environmental factors govern this high percentage of the volume inhabited (PVI2) by submerged

Prevalence and usage of printed and electronic drug references and patient medication records in community pharmacies in Malaysia.

Science.gov (United States)

Usir, Ezlina; Lua, Pei Lin; Majeed, Abu Bakar Abdul

2012-06-01

This study aimed to determine the availability and usage of printed and electronic references and Patient Medication Record in community pharmacy. It was conducted for over 3 months from 15 January to 30 April 2007. Ninety-three pharmacies participated. Structured questionnaires were mailed to community pharmacies. Six weeks later a reminder was sent to all non responders, who were given another six weeks to return the completed questionnaire. Outcomes were analyzed using descriptive statistics and chi-square test of independence. Almost all the pharmacies (96.8%) have at least Monthly Index of Medical Specialties (MIMS) while 78.5% have at least MIMS ANNUAL in their stores. Only about a third (31.2%) of the pharmacies were equipped with online facilities of which the majority referred to medical websites (88.9%) with only a minority (11.1%) referring to electronic journals. More than half (59.1%) of the pharmacists kept Patient Medication Record profiles with 49.1% storing it in paper, 41.8% electronically and 9.1% in both printed and electronic versions. In general, prevalence and usage of electronic references in community pharmacies were rather low. Efforts should be increased to encourage wider usage of electronic references and Patient Medication Records in community pharmacies to facilitate pharmaceutical care.

Flow Management to Control Excessive Growth of Macrophytes – An Assessment Based on Habitat Suitability Modeling

Science.gov (United States)

Ochs, Konstantin; Rivaes, Rui P.; Ferreira, Teresa; Egger, Gregory

2018-01-01

Mediterranean rivers in intensive agricultural watersheds usually display outgrowths of macrophytes – notably alien species – due to a combination of high concentrations of nutrients in the water runoff and low flows resulting from water abstraction for irrigation. Standard mechanical and chemical control is used to mitigate the problems associated with excessive growth of plant biomass: mainly less drainage capacity and higher flood risk. However, such control measures are cost and labor-intensive and do not present long-term efficiency. Although the high sensitivity of aquatic vegetation to instream hydraulic conditions is well known, management approaches based on flow management remain relatively unexplored. The aim of our study was therefore to apply physical habitat simulation techniques promoted by the Instream Flow Incremental Method (IFIM) to aquatic macrophytes – the first time it has been applied in this context – in order to model shifts in habitat suitability under different flow scenarios in the Sorraia river in central Portugal. We used this approach to test whether the risk of invasion and channel encroachment by nuisance species can be controlled by setting minimum annual flows. We used 960 randomly distributed survey points to analyze the habitat suitability for the most important aquatic species (including the invasive Brazilian milfoil Myriophyllum aquaticum, Sparganium erectum, and Potamogeton crispus) in regard to the physical parameters ‘flow velocity,’ ‘water depth,’ and ‘substrate size’. We chose the lowest discharge period of the year in order to assess the hydraulic conditions while disturbances were at a low-point, thus allowing aquatic vegetation establishment and subsistence. We then used the two-dimensional hydraulic River2D software to model the potential habitat availability for different flow conditions based on the site-specific habitat suitability index for each physical parameter and species. Our results show

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.

.85 Co 16.7 20.6 12.8 23 Table: 2I: Heavy metal concentrations in Nelymbium speciosum Heavy metal (? g/g dry wt.) Nelymbium speciosum Root (0.0505) Stem (0.0504) Leaf (0.0503) Flower.... The metals are thereby made available to grazing moluscs and, thus, reintroduced into the food web via fish to birds and humans. In addition, macrophytes in shallow coastal zones function as living filters for nutrients and metals that become bound...

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.

ENVIRONMENTAL FACTORS INFLUENCING THE VEGETATION IN MIDDLE-SIZED STREAMS IN LATVIA

Directory of Open Access Journals (Sweden)

L. GRINBERGA

2011-04-01

Full Text Available In this study the species diversity and distribution of macrophytes in 131 surveyed sites of middle-sized streams of Latvia were investigated. The aim of the study was to determine the composition of macrophyte vegetation in Latvian streams in relation to the environmental factors (stream width, water depth, substrate type, shading and flow velocity. On the basis of these factors, five major groups of streams were distinguished representing mutually different typical macrophyte communities – (1 fast flowing streams on gravelly and stony substrate, (2 slow flowing streams on gravelly and stony substrate, (3 fast flowing streams on sandy substrate, (4 slow flowing streams on sandy substrate, and (5 streams with soft, silty substrate. Totally, 47 macrophyte taxa were found in the streams. The most common macrophyte species were Nuphar lutea found in 65% of all sites, followed by Sparganium emersum (64%, S. erectum s.l. (48%, Phalaris arundinacea (50%, Alisma plantago-aquatica (54% and Lemna minor (41%. The highest species richness (22 was found in slow flowing streams with gravelly substrate. Species-poor macrophyte communities were characteristic for fast flowing streams on sandy substrate.

ENVIRONMENTAL FACTORS INFLUENCING THE VEGETATION IN MIDDLE-SIZED STREAMS IN LATVIA

Directory of Open Access Journals (Sweden)

L. GRINBERGA

2011-01-01

Full Text Available In this study the species diversity and distribution of macrophytes in 131 surveyed sites of middle-sized streams of Latvia were investigated. The aim of the study was to determine the composition of macrophyte vegetation in Latvian streams in relation to the environmental factors (stream width, water depth, substrate type, shading and flow velocity. On the basis of these factors, five major groups of streams were distinguished representing mutually different typical macrophyte communities – (1 fast flowing streams on gravelly and stony substrate, (2 slow flowing streams on gravelly and stony substrate, (3 fast flowing streams on sandy substrate, (4 slow flowing streams on sandy substrate, and (5 streams with soft, silty substrate. Totally, 47 macrophyte taxa were found in the streams. The most common macrophyte species were Nuphar lutea found in 65% of all sites, followed by Sparganium emersum (64%, S. erectum s.l. (48%, Phalaris arundinacea (50%, Alisma plantago-aquatica (54% and Lemna minor (41%. The highest species richness (22 was found in slow flowing streams with gravelly substrate. Species-poor macrophyte communities were characteristic for fast flowing streams on sandy substrate.

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

DEFF Research Database (Denmark)

Kiørboe, Thomas

1980-01-01

waterfowl plant consumption in the entire area (1400 ha) was estimated as 283 t ash-free dry wt, representing about 30% (15-60%) of the annual macrophyte production (968 t ash-free dry wt), or nearly half the maximum biomass. In spite of this high percentage, the direct effect of grazing could...

Mowing Submerged Macrophytes in Shallow Lakes with Alternative Stable States: Battling the Good Guys?

Science.gov (United States)

Kuiper, Jan J.; Verhofstad, Michiel J. J. M.; Louwers, Evelien L. M.; Bakker, Elisabeth S.; Brederveld, Robert J.; van Gerven, Luuk P. A.; Janssen, Annette B. G.; de Klein, Jeroen J. M.; Mooij, Wolf M.

2017-04-01

Submerged macrophytes play an important role in maintaining good water quality in shallow lakes. Yet extensive stands easily interfere with various services provided by these lakes, and harvesting is increasingly applied as a management measure. Because shallow lakes may possess alternative stable states over a wide range of environmental conditions, designing a successful mowing strategy is challenging, given the important role of macrophytes in stabilizing the clear water state. In this study, the integrated ecosystem model PCLake is used to explore the consequences of mowing, in terms of reducing nuisance and ecosystem stability, for a wide range of external nutrient loadings, mowing intensities and timings. Elodea is used as a model species. Additionally, we use PCLake to estimate how much phosphorus is removed with the harvested biomass, and evaluate the long-term effect of harvesting. Our model indicates that mowing can temporarily reduce nuisance caused by submerged plants in the first weeks after cutting, particularly when external nutrient loading is fairly low. The risk of instigating a regime shift can be tempered by mowing halfway the growing season when the resilience of the system is highest, as our model showed. Up to half of the phosphorus entering the system can potentially be removed along with the harvested biomass. As a result, prolonged mowing can prevent an oligo—to mesotrophic lake from becoming eutrophic to a certain extent, as our model shows that the critical nutrient loading, where the lake shifts to the turbid phytoplankton-dominated state, can be slightly increased.

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.

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.

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

Science.gov (United States)

Bottino, Flávia; Cunha-Santino, Marcela Bianchessi; Bianchini, Irineu

2016-01-01

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. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Effect of alkaline pretreatment on mesophilic and thermophilic anaerobic digestion of a submerged macrophyte: Inhibition and recovery against dissolved lignin during semi-continuous operation.

Science.gov (United States)

Koyama, Mitsuhiko; Watanabe, Keiko; Kurosawa, Norio; Ishikawa, Kanako; Ban, Syuhei; Toda, Tatsuki

2017-08-01

The long-term effect of alkaline pretreatment on semi-continuous anaerobic digestion (AD) of the lignin-rich submerged macrophyte Potamogeton maackianus was investigated using mesophilic and thermophilic conditions. In pretreated reactors, dissolved lignin accumulated to high levels. CH 4 production under the pretreated condition was higher than that of the untreated condition, but decreased from Days 22 (mesophilic) and 42 (thermophilic). However, CH 4 production subsequently recovered, although dissolved lignin accumulated. Further, the change in the microbial community was observed between conditions. These results suggest that dissolved lignin temporarily inhibited AD, although acclimatization to dissolved lignin occurred during long-term operation. During the steady state period, mesophilic conditions achieved a 42% increase in the CH 4 yield using pretreatment, while thermophilic conditions yielded an 8% increment. Because volatile fatty acids accumulated even after acclimatization during the thermophilic pretreated condition and was discharged with the effluent, improvement of the methanogenic step would enable enhanced CH 4 recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Decomposition of macrophytes with uniformly C-14-labelled plant material

International Nuclear Information System (INIS)

Blake, G.

1979-01-01

Uniform labelling of plant such as macrophytes is relatively difficult to obtain. In my experiments I used samples of ripe stems and leaves of labelled maize which had grown for 110 days in a 14 Co 2 atmosphere. These samples were laid in a glass bowl for in situ and in vitro experiments under similar conditions of light and temperature. The aim of this study was to determine the shift of carbon through chosen compartments of a core (water, sediments, bacteria, invertebrates, atmosphere) and to understand the mineralization process with type of particulate organic matter. At low temperature (7 0 C), leaching of organic matter in the first 5 days increases bacteria activity, then radioactivity-incorporation level declines to the 60th day; CO 2 production was measured during experiments and was varying between 60% and 75% of used carbon of the tissue. (orig.) [de

[Experimental investigations of 211Am accumulation by macrophytes of the Yenisei River].

Science.gov (United States)

Bolsunovskiĭ, A Ia; Zotina, T A

2002-01-01

Experiments were carried out in which 241Am was added to water samples containing macrophytes of the Yenisei River, and the radionuclide absorption rates and concentration factors were determined for the plants. It has been shown that the water moss (Fontinalis antipyretica) has a higher capacity to accumulate 241Am than the Canadian pondweed (Elodea canadensis) does. The laboratory experiments revealed that the capacity of dead biomass of the Canadian pondweed to accumulate 241Am is twice higher than that of living biomass. In contrast, no significant increase in 241Am accumulation by dead biomass of the water moss has been recorded. The transuranic element 241Am was firmly fixed by the plant biomass and was not released into water in the course of long-duration experiments.

Methane emission from natural wetlands: interplay between emergent macrophytes and soil microbial processes. A mini-review

Science.gov (United States)

Laanbroek, Hendrikus J.

2010-01-01

Background According to the Intergovernmental Panel on Climate Change (IPCC) 2007, natural wetlands contribute 20–39 % to the global emission of methane. The range in the estimated percentage of the contribution of these systems to the total release of this greenhouse gas is large due to differences in the nature of the emitting vegetation including the soil microbiota that interfere with the production and consumption of methane. Scope Methane is a dominant end-product of anaerobic mineralization processes. When all electron acceptors except carbon dioxide are used by the microbial community, methanogenesis is the ultimate pathway to mineralize organic carbon compounds. Emergent wetland plants play an important role in the emission of methane to the atmosphere. They produce the carbon necessary for the production of methane, but also facilitate the release of methane by the possession of a system of interconnected internal gas lacunas. Aquatic macrophytes are commonly adapted to oxygen-limited conditions as they prevail in flooded or waterlogged soils. By this system, oxygen is transported to the underground parts of the plants. Part of the oxygen transported downwards is released in the root zone, where it sustains a number of beneficial oxidation processes. Through the pores from which oxygen escapes from the plant into the root zone, methane can enter the plant aerenchyma system and subsequently be emitted into the atmosphere. Part of the oxygen released into the root zone can be used to oxidize methane before it enters the atmosphere. However, the oxygen can also be used to regenerate alternative electron acceptors. The continuous supply of alternative electron acceptors will diminish the role of methanogenesis in the anaerobic mineralization processes in the root zone and therefore repress the production and emission of methane. The role of alternative element cycles in the inhibition of methanogenesis is discussed. Conclusions The role of the nitrogen

The Community Integration Questionnaire - Revised: Australian normative data and measurement of electronic social networking.

Science.gov (United States)

Callaway, Libby; Winkler, Dianne; Tippett, Alice; Herd, Natalie; Migliorini, Christine; Willer, Barry

2016-06-01

Consideration of the relationship between meaningful participation, health and wellbeing underpins occupational therapy intervention, and drives measurement of community integration following acquired brain injury (ABI). However, utility of community integration measures has been limited to date by lack of normative data against which to compare outcomes, and none examine the growing use of electronic social networking (ESN) for social participation. This research had four aims: (i) develop and pilot items assessing ESN to add to the Community Integration Questionnaire, producing the Community Integration Questionnaire-Revised (CIQ-R); (ii) examine factor structure of the CIQ-R; (iii) collect Australian CIQ-R normative data; and (iv) assess test-retest reliability of the revised measure. Australia. A convenience sample of adults without ABI (N = 124) was used to develop and pilot ESN items. A representative general population sample of adults without ABI aged 18-64 years (N = 1973) was recruited to gather normative CIQ-R data. Cross-sectional survey. Demographic items and the CIQ-R. The CIQ-R demonstrated acceptable psychometric properties, with minor modification to the original scoring based on the factor analyses provided. Large representative general population CIQ-R normative data have been established, detailing contribution of a range of independent demographic variables to community integration. The addition of electronic social networking items to the CIQ-R offers a contemporary method of assessing community integration following ABI. Normative CIQ-R data enhance the understanding of community integration in the general population, allowing occupational therapists and other clinicians to make more meaningful comparisons between groups. © 2016 Occupational Therapy Australia.

Interactions between piscivores, zooplanktivores and zooplankton in submerged macrophytes : Preliminary observations from enclosure and pond experiments

DEFF Research Database (Denmark)

Jacobsen, Lene; Perrow, M.R.; Landkildehus, F.

1997-01-01

behavioural changes of zooplanktivores has received little attention, even though this may be an important mechanism in enhancing the stability of submerged macrophytes in shallow lakes. Preliminary observations from an unreplicated large-scale field enclosure experiment and a replicated pond experiment...... and the presence of zooplanktivores typically changed the habitat selection of cladoceran zooplankton. In the case of piscivore/zooplanktivore interactions, the risk of predation was enough to generate clear responses even where the losses to predation were low. However, only in the enclosure experiment...

Peculiar features of the Chernobyl release plutonium and americium accumulation by macrophytes of water systems in Gomel region

International Nuclear Information System (INIS)

Kudryashov, V.P.; Gaponenko, V.I.; Zubareva, A.V.

2008-01-01

Investigation of transuranian elements 239Pu, 240Pu, 241Am, as well as 137Cs and 90Sr after Chernobyl accident release adsorption and accumulation by the macrophytes of water systems in Gomel region of the Republic of Belarus was realized. Noted biological diversity in accumulation of radionuclides by the terrain flora was also typical for the higher aquatic plants. Research results showed that the degree of accumulation depended on the morphophysiological peculiarities of each plant body. Various indices of radionuclide accumulation coefficient for each analysed transuranian element were stated in one and the same aquatic media with the equal physical and chemical properties. Accumulation of transuranian elements by macrophytes was determined by the peculiar properties of radionuclides as chemical elements and by the forms of their existence in the aqueous media. In one and the same analysed plant of the certain water system the accumulation coefficients of different radionuclides differed. Similarity in concentrations of different radionuclides in all studied water systems was analysed. Research results showed that accumulation indices of comparatively easity determined 137Cs could help to determine the relative concentration of other radionuclides which could be analyzed with more difficulties (90 Sr, and especially 239Pu, 240Pu, 241Am)

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.

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.

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.

Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

International Nuclear Information System (INIS)

Coelho-Souza, Sergio A.; Guimaraes, Jean R.D.; Miranda, Marcio R.; Poirier, Hugo; Mauro, Jane B.N.; Lucotte, Marc; Mergler, Donna

2011-01-01

Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ 13 C, δ 15 N and bacterial heterotrophic production as 3 H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me 203 Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me 203 Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ 13 C. The discriminant analysis showed a significant difference in periphyton δ 15 N, δ 13 C and THg between seasons, where the rainy season presented higher δ 15 N and the wet period lighter δ 13 C, lower THg values and higher Me 203 Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: → During rainy season mercury (Hg 2+ ) is carried out from terrestrial to aquatic systems by runoff. → Macrophyte roots accumulates Hg 2+ from suspended particulate matter (SPM). → Hg methylation increases during the wet season. → Flooded forest is a source of labile organic carbon and bioavailable Hg. → Macrophytes decompose during the dry season and made up terrestrial soil.

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.

Long-term hydrologic effects on marsh plant community structure in the southern Everglades

Science.gov (United States)

Busch, David E.; Loftus, W.F.; Bass, O.L.

1998-01-01

Although large-scale transformation of Everglades landscapes has occurred during the past century, the patterns of association among hydrologic factors and southern Everglades freshwater marsh vegetation have not been well-defined. We used a 10-year data base on the aquatic biota of Shark Slough to classify vegetation and describe plant community change in intermediate- to long-hydroperiod Everglades marshes. Study area marsh vegetation was quantitatively grouped into associations dominated by 1) Cladium jamaicense, 2) a group of emergents including Eleocharis cellulosa, Sagittaria lancifolia, and Rhyncospora tracyi, 3) taxa associated with algal mats (Utricularia spp. and Bacopa caroliniana), and 4) the grasses Panicum hemitomon and Paspalidium geminatum. During the decade evaluated, the range of water depths that characterized our study sites approached both extremes depicted in the 40-year hydrologic record for the region. Water depths were near the long-term average during the mid-1980s, declined sharply during a late 1980s drought, and underwent a prolonged increase from 1991 through 1995. Overall macrophyte cover varied inversely with water depth, while the response of periphyton was more complex. An ordination analysis, based on plant species abundance, revealed that study area vegetation structure was associated with hydrologic patterns. Marsh plant community structure showed evidence of cyclic interannual variation corresponding to hydrologic change over the decade evaluated. Lower water depths, the occurrence of marl substrates, and high periphyton cover were correlated. These factors contributed to reduced macrophyte cover in portions of the study area from which water had been diverted.

Distribution and abundance of submerged aquatic macrophytes in a reactor cooling reservoir

Energy Technology Data Exchange (ETDEWEB)

Grace, J.B.

1977-08-01

Measurements of ash-free dry weight were used to characterize the effects of a heated effluent on submerged macrophytes in a reactor cooling reservoir. The species which were most abundant during the summers of 1974 and 1975 were Myriophyllum spicatum L. and Eleocharis acicularis (L.) R. and S. Examination of the vertical distribution of the shoot biomass of Myriophyllum revealed that plants in heated areas grew closer to the water surface than plants in unheated areas. The biomass of the second most abundant species, Eleocharis acicularis, was less at 0.5 m depths in heated areas (more than 5C/sup 0/ warmer than unheated areas) than at equal depths in unheated areas. Species diversity was greater at heated locations because of a greater equitability (i.e., evenness of distribution of biomass) among species.

Recovery of lake vegetation following reduced eutrophication and acidification

DEFF Research Database (Denmark)

Båstrup-Spohr, Lars; Sand-Jensen, Kaj; Olesen, Sissel C. H.

2017-01-01

in pollution control has been successful in terms of markedly improving water quality of lakes and, with a time lag, macrophyte species richness. Although relatively common species have spread across lakes and resulted in homogenised macrophyte communities, continued efforts to reduce pollution could ensure...

Introduction of electronic referral from community associated with more timely review by secondary services.

Science.gov (United States)

Warren, J; White, S; Day, K J; Gu, Y; Pollock, M

2011-01-01

Electronic referral (eReferral) from community into public secondary healthcare services was introduced to 30 referring general medical practices and 28 hospital based services in late 2007. To measure the extent of uptake of eReferral and its association with changes in referral processing. Analysis of transactional data from the eReferral message service and the patient information management system of the affected hospital; interview of clinical, operational and management stakeholders. eReferral use rose steadily to 1000 transactions per month in 2008, thereafter showing moderate growth to 1200 per month in 2010. Rate of eReferral from the community in 2010 is estimated at 56% of total referrals to the hospital from general practice, and as 71% of referrals from those having done at least one referral electronically. Referral latency from letter date to hospital triage improves significantly from 2007 to 2009 (psystem usability issues. With eReferrals, a referral's status can be checked, and its content read, by any authorized user at any time. The period of eReferral uptake was associated with significant speed-up in referral processing without changes in staffing levels. The eReferral system provides a foundation for further innovation in the community-secondary interface, such as electronic decision support and shared care planning systems. We observed substantial rapid voluntary uptake of eReferrals associated with faster, more reliable and more transparent referral processing.

Global sale of tobacco products and electronic nicotine delivery systems in community pharmacies.

Science.gov (United States)

Hudmon, Karen Suchanek; Elkhadragy, Nervana; Kusynová, Zuzana; Besançon, Luc; Brock, Tina Penick; Corelli, Robin L

2017-12-01

To estimate the proportion of countries/territories that allow sales of tobacco products and electronic nicotine delivery systems (ENDS) in community pharmacies. International Pharmaceutical Federation (FIP) member organisations were contacted by email and asked to respond to a two-item survey assessing whether their country/territory allowed sales of (a) tobacco products and (b) ENDS in community pharmacies. Of 95 countries/territories contacted, responses were received from 60 (63.2%). Seven countries (11.7%) reported that tobacco products were sold in community pharmacies, and 11 countries (18.3%) reported that ENDS were sold in community pharmacies. Among the FIP member organisations, there are few countries that allow the sale of tobacco products and ENDS in community pharmacies, with ENDS being more likely than tobacco products to be sold. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Ecological Stoichiometry Characteristics of Aquatic Macrophytes in the Decomposition Process%水生植物分解过程中生态化学计量学特征研究

Institute of Scientific and Technical Information of China (English)

张雷燕; 关保华; 程寒飞; 詹茂华

2017-01-01

Plant matter from three macrophytes from different environments was dried and analyzed over time to in-vestigate macrophyte stoichiometry during decomposition and the effect of environment on macrophyte stoichiometry . A floating plant, Lemna minor, and two submerged plants, Vallisneria natans and Potamogeton malaianus, were prepared and placed in three water environments:Treatment A:beaker with 200 mL tap water +3 cm of sediment in a greenhouse;Treatment B: beaker with 200 mL tap water in a greenhouse; Treatment C: in situ in a pond. Each treatment was run in triplicate with six plants per trial.Each week for five weeks, one plant was randomly se-lected from each treatment for determination of dry weight, TN, TC and TP.The C/N range in the three macro-phytes was 7.43-10.06, much lower than the global level of 22.5, and the C/P range was 43.09-91.77, sig-nificantly higher than the global level of 23.2.The results indicate that, with the same assimilation capacity of C, the utilization efficiency of N is higher than that of P.The N/P range (4.71-9.24) in the three macrophytes was lower than the global level of 14, showing that N was the limiting nutrient for the macrophytes.Furthermore, the submerged plants V.natans, and P.malaianus exhibited similar C/N ratios in the greenhouse and under natural conditions, indicating a consistent release rate of C and N from the submerged macrophytes and implying a small environmental effect.However, the C/N ratio of L.minor varied markedly between treatments, implying a large environmental effect.The C/N ratio in L.minor and V.natans increased rapidly at the beginning, indicating that the release rate of N from both macrophytes was higher than the release rate of C.The C/P and N/P ratio in the three macrophytes increased rapidly in the first week and the ratios varied significantly among the three groups.This indicates that the P release rate from the three macrophytes was higher than the release rates of C and N during the first

What is left? Macrophyte meadows and Atlantic herring (Clupea harengus) spawning sites in the Greifswalder Bodden, Baltic Sea

Science.gov (United States)

Kanstinger, Philipp; Beher, Jutta; Grenzdörffer, Görres; Hammer, Cornelius; Huebert, Klaus B.; Stepputis, Daniel; Peck, Myron A.

2018-02-01

Coastal zones are productive areas of marine ecosystems which are also hotspots of anthropogenic activities causing habitat degradation. In the southwest Baltic Sea, eutrophication is thought to have caused the massive reduction in submerged macrophytes observed in recent decades. Here, we surveyed the submarine vegetation and examined locations of spawning of herring (Clupea harengus) in the Greifswalder Bodden, one of the most important reproductive habitats of the Western Baltic Spring Spawner herring stock (WBSS). This stock deposits eggs onto submerged vegetation and changes in macrophyte coverage are expected to influence the availability of reproductive habitat. Aerial, underwater video tows and SCUBA surveys conducted in spring 2009 revealed that only ∼7% of the lagoon was vegetated. Herring eggs were observed on 12 of 32 SCUBA transects, at depths between 0.2 and 5 m and were attached to a variety of spermatophyte and algae species but not to stones or mussels. A classification tree model indicated that spawning sites were strongly associated with the vegetation cover within a 100- and 500-m radius, implying that herring schools preferentially spawn on dense and large underwater meadows. Only ∼5% of the lagoon now falls into this vegetation category. Despite 20 years of efforts to reduce eutrophication, no increase in macroalgae and spermatophyte vegetation towards the historical level of 90% coverage in the area is apparent.

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

Science.gov (United States)

LIU, S. S.; Zhu, Y.; Meng, W.; Wu, F.

2016-12-01

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 13C NMR and solution 31P 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.

Updated records and range expansion of alien marine macrophytes in Greece (2009

Directory of Open Access Journals (Sweden)

K. TSIAMIS

2010-02-01

Full Text Available In the present study the list of alien marine macrophytes already recorded on Greek coasts has been revised in the light of recent studies and new observations. In comparison  to 2008, the total number consists of 32 taxa, and the classification as established, casual and debatable species has been modified, with a total of 14, 5 and 13 species respectively. An interesting increase in established species from 9 taxa in 2008 to 14 taxa in 2009 is noted. With 23 taxa listed, Rhodobionta is the best represented group, followed by Chlorobionta (4 taxa and Chromobionta (4 taxa, while seagrasses (Streptobionta are represented by only one species. Several new records, one new entry and two putative additions are considered here, while two other taxa previously assumed introduced are excluded from the list of aliens.

Performance of free water surface flow constructed wetland with floating aquatic macrophytes

Directory of Open Access Journals (Sweden)

C. Soler

2018-04-01

Full Text Available The aim of this study was to evaluate the behavior of constructed wetlands with aquatic macrophytes in decreasing the concentration of pollutants from urban effluents. A pilot-scale system with two coverages of floating plants and two hydraulic residence times, working with continuous flow laminar was built. The lower concentration of chemical oxygen demand and biological oxygen demand, were obtained with the lower coverage and higher hydraulic residence times. With little influence of the variables on the concentration of total nitrogen and total suspended solids, being the significant response for total phosphorus with the lowest plant coverage. There was a highly significant removal of total coliforms, regardless of coverage and in favor of higher hydraulic residence times. The use of free water surface wetlands is auspicious for sanitary control, showing low incidence on total nitrogen and total phosphorus.

Response and recovery of the macrophytes Elodea canadensis and Myriophyllum spicatum following a pulse exposure to the herbicide iofensulfuron-sodium in outdoor stream mesocosms.

Science.gov (United States)

Wieczorek, Matthias V; Bakanov, Nikita; Lagadic, Laurent; Bruns, Eric; Schulz, Ralf

2017-04-01

Interest in stream mesocosms has recently revived for higher tier aquatic macrophyte risk assessment of plant protection products mainly because 1) the highest predicted environmental concentrations for the assessment of effects are frequently derived from stream scenarios, and 2) they allow an effect assessment using stream-typical pulse exposures. Therefore, the present stream mesocosm study used an herbicide pulse exposure and evaluated the responses of Elodea canadensis and Myriophyllum spicatum. Macrophytes were exposed for 24 h to 1 μg/L, 3 μg/L, 10 μg/L, and 30 μg/L of the herbicide iofensulfuron-sodium with a subsequent recovery period of 42 d. Biological endpoints were growth rates of the main, side, and total shoot length, the shoot number, the maximum root length, and the dry weight. The total shoot length was identified as the most sensitive endpoint; the growth rate of the total shoot length was inhibited by up to 66% and 45% in M. spicatum and E. canadensis, respectively. The lowest no observed effect concentrations (NOECs) were observed at day 7 and/or day 14 after herbicide treatment and were 1 μg/L for M. spicatum and 3 μg/L for E. canadensis. The no-observed-ecologically-adverse-effect concentrations (NOEAECs) were 10 μg/L and 30 μg/L for M. spicatum and E. canadensis, respectively. Such or similar mesocosm designs are useful to simulate typical stream exposures and estimate herbicide effects on aquatic macrophytes in stream systems. Environ Toxicol Chem 2017;36:1090-1100. © 2016 SETAC. © 2016 SETAC.

Iplt--image processing library and toolkit for the electron microscopy community.

Science.gov (United States)

Philippsen, Ansgar; Schenk, Andreas D; Stahlberg, Henning; Engel, Andreas

2003-01-01

We present the foundation for establishing a modular, collaborative, integrated, open-source architecture for image processing of electron microscopy images, named iplt. It is designed around object oriented paradigms and implemented using the programming languages C++ and Python. In many aspects it deviates from classical image processing approaches. This paper intends to motivate developers within the community to participate in this on-going project. The iplt homepage can be found at http://www.iplt.org.

Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

Energy Technology Data Exchange (ETDEWEB)

Coelho-Souza, Sergio A., E-mail: sacs@biof.ufrj.br [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Guimaraes, Jean R.D.; Miranda, Marcio R. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Poirier, Hugo [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mauro, Jane B.N. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Lucotte, Marc [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mergler, Donna [CINBIOSE, UQaM, CP 8888, succ. Centre-ville, Montreal, H3C 3P8 (Canada)

2011-06-15

Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, {delta}{sup 13}C, {delta}{sup 15}N and bacterial heterotrophic production as {sup 3}H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me{sup 203}Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me{sup 203}Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and {delta}{sup 13}C. The discriminant analysis showed a significant difference in periphyton {delta}{sup 15}N, {delta}{sup 13}C and THg between seasons, where the rainy season presented higher {delta}{sup 15}N and the wet period lighter {delta}{sup 13}C, lower THg values and higher Me{sup 203}Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: {yields} During rainy season mercury (Hg{sup 2+}) is carried out from terrestrial to aquatic systems by runoff. {yields} Macrophyte roots accumulates Hg{sup 2+} from suspended particulate matter (SPM). {yields} Hg methylation increases during the wet season. {yields} Flooded forest is a source of labile organic carbon and bioavailable Hg. {yields} Macrophytes

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.

2016-11-01

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 < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes.

Nutrient uptake from liquid digestate using ornamental aquatic macrophytes (Canna indica, Iris pseudacorus, Typha latifolia) in a constructed wetland system

Science.gov (United States)

Ediviani, W.; Priadi, C. R.; Moersidik, S. S.

2018-05-01

Indonesia has implemented energy recovery from organic (food) waste by anaerobic digestion method, but the digestate was commonly treated only by composting, and still as a separated treatment (not integrated into a resource recovery system). Whilst not getting any pretreatment, the digestate was disposed to the environment and then act as a pollutant. Yet it contains nutrients which could be recovered as a nutrient source for plants. The study was about how ornamental aquatic macrophytes could uptake nitrogen from liquid digestate in a constructed wetland method. Canna indica, Iris pseudacorus, and Typha latifolia were the experimented ornamental aquatic macrophytes used to uptake the nutrient (nitrogen—N) from liquid digestate. The study showed that the highest N uptake was done by C. indica (25.1%) which has the highest biomass increment as well (80.5%). Effluent quality improvement also shown by N removal by C. indica (68.5—76.4% TN), I. pseudacorus (61.8—71.3% TN), and T. latifolia (61.6—74.5%). This research proved that C. indica has the performance for the N uptake, best N removal efficiency, with a great growth rate as well. This system using C. indica could also improve the water quality of the effluent and add the aesthetic of environment.

The effect of β-N-methylamino-L-alanine (BMAA) on oxidative stress response enzymes of the macrophyte Ceratophyllum demersum.

Science.gov (United States)

Esterhuizen-Londt, M; Pflugmacher, S; Downing, T G

2011-04-01

Cyanobacteria are known to produce bioactive secondary metabolites such as hepatotoxins, cytotoxins and neurotoxins. The newly recognized neurotoxin β-N-methylamino-L-alanine (BMAA) is a naturally occurring non-protein amino acid found in the majority of cyanobacterial genera tested. Evidence that exists for implication of BMAA in neurodegenerative disorders relies on bioaccumulation and biomagnification from symbiotic cyanobacteria. Uptake and accumulation of free BMAA by various non-symbiotic organisms, including aquatic macrophytes, has been documented but to date limited evidence of ecotoxicology exists. We therefore investigated the effect of BMAA on the oxidative stress responses of the macrophyte, Ceratophyllum demersum. Markers for oxidative stress in this study are the antioxidative enzymes superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase and glutathione reductase. We found that BMAA had an inhibitory effect on all the oxidative stress response enzymes tested in plants exposed to BMAA. However enzymes not related to oxidative stress response were not affected by BMAA in in vitro experiments. Binding studies in the presence of BMAA showed reduced enzyme specific activity over time compared to the control. This study shows that BMAA causes oxidative stress indirectly as it inhibits antioxidant enzymes required to combat reactive oxygen species that cause damage to cells. Further investigations are required to fully understand the inhibitory effect of BMAA on these enzymes. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Using Electronic Portfolio to Promote Professional Learning Community for Pre-Service Early Childhood Teachers at Alquds University

Science.gov (United States)

Khales, Buad

2016-01-01

The present study aims to explore whether the electronic portfolio can influence pre-service teachers' education and to examine how professional learning communities develop through electronic portfolios. To achieve this, twenty-four student-teachers taking a course in early childhood education at Al-Quds University participated in a study to…

Micropropagation of Myriophyllum alterniflorum (Haloragaceae) for stream rehabilitation: first in vitro culture and reintroduction assays of a heavy-metal hyperaccumulator immersed macrophyte.

Science.gov (United States)

Delmail, David; Labrousse, Pascal; Hourdin, Philippe; Larcher, Laure; Moesch, Christian; Botineau, Michel

2013-01-01

Nowadays, submersed aquatic macrophytes play a key role in stream ecology and they are often used as biomonitors of freshwater quality. So, these plants appear as natural candidates to stream rehabilitation experiments. Among them, the stream macrophyte Myriophyllum alterniflorum is used recently as biomonitor and is potentially useful for the restoration of heavy-metal contaminated localities. The best way to obtain a mass production of watermilfoil plants is micropropagation. We developed in vitro culture of M. alterniflorum and the effects of five media on the plant development were assessed. Five morphological and four physiological endpoints were examined leading to the recommendation of the Murashige and Skoog medium for ecotoxicological studies on chlorophyllous parts, and of the Gaudet medium for root cytotoxicity and phytoremediation studies. Micropropagated clones were acclimatized in a synthetic medium and in situ reintroduction was performed efficiently. This is the first report of micropropagated plants transplantation in streams. The successful establishment of watermilfoil beds even in polluted areas strongly suggested that ecological restoration using micropropagated watermilfoil is a promising biotechnology for phytoremediation and rehabilitation of degraded areas. Moreover, high bioconcentration factors evidenced that watermilfoil hyperaccumulates Cd and Cu, and could be potentially used in phytoremediation studies.

Electronic Personal Health Record Use Among Nurses in the Nursing Informatics Community.

Science.gov (United States)

Gartrell, Kyungsook; Trinkoff, Alison M; Storr, Carla L; Wilson, Marisa L

2015-07-01

An electronic personal health record is a patient-centric tool that enables patients to securely access, manage, and share their health information with healthcare providers. It is presumed the nursing informatics community would be early adopters of electronic personal health record, yet no studies have been identified that examine the personal adoption of electronic personal health record's for their own healthcare. For this study, we sampled nurse members of the American Medical Informatics Association and the Healthcare Information and Management Systems Society with 183 responding. Multiple logistic regression analysis was used to identify those factors associated with electronic personal health record use. Overall, 72% were electronic personal health record users. Users tended to be older (aged >50 years), be more highly educated (72% master's or doctoral degrees), and hold positions as clinical informatics specialists or chief nursing informatics officers. Those whose healthcare providers used electronic health records were significantly more likely to use electronic personal health records (odds ratio, 5.99; 95% confidence interval, 1.40-25.61). Electronic personal health record users were significantly less concerned about privacy of health information online than nonusers (odds ratio, 0.32; 95% confidence interval, 0.14-0.70) adjusted for ethnicity, race, and practice region. Informatics nurses, with their patient-centered view of technology, are in prime position to influence development of electronic personal health records. Our findings can inform policy efforts to encourage informatics and other professional nursing groups to become leaders and users of electronic personal health record; such use could help them endorse and engage patients to use electronic personal health records. Having champions with expertise in and enthusiasm for the new technology can promote the adoptionof electronic personal health records among healthcare providers as well as

High performance liquid chromatography profiling of health-promoting phytochemicals and evaluation of antioxidant, anti-lipoxygenase, iron chelating and anti-glucosidase activities of wetland macrophytes.

Science.gov (United States)

Ooh, Keng-Fei; Ong, Hean-Chooi; Wong, Fai-Chu; Sit, Nam-Weng; Chai, Tsun-Thai

2014-08-01

The phytochemistry and bioactivity of wetland macrophytes are underexplored. Plants are known as the natural sources of phytochemical beneficial to health. The objective of this study is to analyze the phytochemical profiles and bioactivities of 10 extracts prepared from different plant parts of wetland macrophytes Hanguana malayana, Ludwigia adscendens and Monochoria hastata. High performance liquid chromatography (HPLC) was used to analyze the phytochemical profile of the extracts. Antioxidant assay such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide (NO) radical scavenging activity and ferric reducing antioxidant power were performed. Bioactivity assays carried out were anti-lipoxygenase, anti-glucosidase, and iron chelating. Leaf extract of L. adscendens had the highest 2,2-diphenyl-1-picrylhydrazyl (half of maximal effective concentration [EC50] =0.97 mg/mL) and NO (EC50 = 0.31 mg/mL) scavenging activities. The extract also exhibited the highest iron chelating (EC50 = 3.24 mg/mL) and anti-glucosidase (EC50 = 27.5 μg/mL) activities. The anti-glucosidase activity of L. adscendens leaf extract was comparable or superior to those of acarbose, myricetin and quercetin. Correlation between iron chelating and radical scavenging activities among the extracts implies the presence of dual-function phytoconstituents with concurrent iron chelating and radical scavenging activities. HPLC analysis revealed the presence of p-coumaric acid (p-CA), gallic acid (GA) and myricetin in all or most extracts. M. hastata fruit and leaf extracts had the highest p-hydroxybenzoic acid content. Antioxidant and anti-glucosidase activities of the extracts were correlated with p-CA, GA, and myricetin contents. Our study demonstrated that wetland macrophytes H. malayana, L. adscendens and M. hastata are potential sources of health-promoting phytochemicals with potent therapeutically-relevant bioactivities.

High performance liquid chromatography profiling of health-promoting phytochemicals and evaluation of antioxidant, anti-lipoxygenase, iron chelating and anti-glucosidase activities of wetland macrophytes

Science.gov (United States)

Ooh, Keng-Fei; Ong, Hean-Chooi; Wong, Fai-Chu; Sit, Nam-Weng; Chai, Tsun-Thai

2014-01-01

Background: The phytochemistry and bioactivity of wetland macrophytes are underexplored. Plants are known as the natural sources of phytochemical beneficial to health. Objective: The objective of this study is to analyze the phytochemical profiles and bioactivities of 10 extracts prepared from different plant parts of wetland macrophytes Hanguana malayana, Ludwigia adscendens and Monochoria hastata. Materials and Methods: High performance liquid chromatography (HPLC) was used to analyze the phytochemical profile of the extracts. Antioxidant assay such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide (NO) radical scavenging activity and ferric reducing antioxidant power were performed. Bioactivity assays carried out were anti-lipoxygenase, anti-glucosidase, and iron chelating. Results: Leaf extract of L. adscendens had the highest 2,2-diphenyl-1-picrylhydrazyl (half of maximal effective concentration [EC50] =0.97 mg/mL) and NO (EC50 = 0.31 mg/mL) scavenging activities. The extract also exhibited the highest iron chelating (EC50 = 3.24 mg/mL) and anti-glucosidase (EC50 = 27.5 μg/mL) activities. The anti-glucosidase activity of L. adscendens leaf extract was comparable or superior to those of acarbose, myricetin and quercetin. Correlation between iron chelating and radical scavenging activities among the extracts implies the presence of dual-function phytoconstituents with concurrent iron chelating and radical scavenging activities. HPLC analysis revealed the presence of p-coumaric acid (p-CA), gallic acid (GA) and myricetin in all or most extracts. M. hastata fruit and leaf extracts had the highest p-hydroxybenzoic acid content. Antioxidant and anti-glucosidase activities of the extracts were correlated with p-CA, GA, and myricetin contents. Conclusion: Our study demonstrated that wetland macrophytes H. malayana, L. adscendens and M. hastata are potential sources of health-promoting phytochemicals with potent therapeutically-relevant bioactivities. PMID:25298659

Exploring the Use of Electronic Mobile Technologies among Distance Learners in Rural Communities for Safe and Disruptive Learning

Science.gov (United States)

Ntloedibe-Kuswani, Gomang Seratwa

2013-01-01

Several studies indicated the potential of electronic mobile technologies in reaching (safe learning) under-served communities and engaging (disruptive learning) disadvantaged peoples affording them learning experiences. However, the potential benefits of (electronic mobile learning) e-mobile learning have not been well understood from the…

The Electronic Health Literacy and Utilization of Technology for Health in a Remote Hawaiian Community: Lana'i.

Science.gov (United States)

Witten, Nash Ak; Humphry, Joseph

2018-03-01

The Lana'i Community Health Center (LCHC) like other health care organizations, is striving to implement technology-enabled care (TEC) in the clinical setting. TEC includes such technological innovations as patient portals, mobile phone applications, wearable health sensors, and telehealth. This study examines the utilization of communication technology by members of the Lana'i community and LCHC staff and board members in the home and in their daily lives and evaluates the community's electronic health literacy. Quantitative surveys and qualitative focus groups were utilized. These revealed that members of the Lana'i community and LCHC staff and board members regularly utilize technology, in the form of smart cell phones, WiFi, and internet texting. This community has integrated technology into their daily lives, even though they live on an isolated island with 3,102 people; however, despite this integration, the electronic health literacy of this population appears insufficient for proper understanding and utilization of TEC, limiting the potential of patient portals or remote monitoring of patient generated data for chronic disease prevention and management without additional education and mentoring. It is therefore in the best interest of the LCHC and other health organizations wishing to implement TEC in a rural community such as Lana'i to include a strong educational component with use of TEC, and perhaps establish a mentor/partnership program for the highly-challenged patient.

Effects of two-hour exposure to environmental and high concentrations of methylmercury on the transcriptome of the macrophyte Elodea nuttallii.

Science.gov (United States)

Beauvais-Flück, Rebecca; Slaveykova, Vera I; Cosio, Claudia

2018-01-01

The effects of two methylmercury (CH 3 Hg + , MeHg) concentrations, representative of environmental level and extreme contamination, were investigated on the macrophyte Elodea nuttallii during a 2h-exposure combining transcriptomic (RNA-Seq), physiological endpoints (pigment contents, activity of anti-oxidative stress enzymes) and bioaccumulation. Exposure to MeHg induced the up- and down-regulation of numerous genes (4389 and 16853 for 10ngL -1 and 10μgL -1 MeHg exposure, respectively) involved in sugar, amino acid and secondary metabolism (e.g. cinnamic acid, flavonoids) at both concentrations. Genes coding for photosynthesis, membrane integrity, metal homeostasis, water transport and anti-oxidative enzymes were additionally up- and down-regulated at the higher concentration. At the physiological level, exposure to both MeHg concentrations resulted in a strong increase of anthocyanin content in shoots. Chlorophyll content and antioxidant enzyme activities were unchanged. The data suggest that the macrophyte was able to efficiently cope with the stress resulting from MeHg exposure, possibly by using anthocyanin as anti-oxidant and S-rich amino acids (such as cysteine and methionine) as chelators. Transcriptomics analysis enabled gaining novel insights on molecular effects of MeHg in primary producers, which are one of the main entry pathway of hazardous MeHg in aquatic food webs. Copyright © 2017 Elsevier B.V. All rights reserved.

Suitability of macrophytes for nutrient removal from surface flow constructed wetlands receiving secondary treated sewage effluent in Queensland, Australia.

Science.gov (United States)

Greenway, M

2003-01-01

From a botanical perspective the major difference between waste stabilisation ponds and wetlands is the dominance of algae or floating plants in the former and emergent plants in the latter. Algae, floating and submerged plants remove nutrients directly from the water column whereas emergent species remove nutrients from the sediment. Water depth is a crucial factor in determining which plant types will become established. Surface flow constructed wetlands offer the greatest potential to grow a wide variety of different types of macrophytes. In assessing the suitability of plant species for nutrient removal, consideration must be given not only to nutrient uptake for growth but also storage of nutrients as plant biomass. A survey of macrophytes in 15 surface flow constructed wetlands treating secondary effluent was conducted in Queensland; 63 native species and 14 introduced species were found. Emergent species have been able to tolerate deeper water than in their natural environment and permanent waterlogging. All species grew well in the higher nutrient enriched wastewater. Submerged, floating leaved-attached and free floating species had the highest tissue nutrient content, followed by aquatic creepers. All these species remove nutrients from the water column. Emergent species had lower nutrient content but a greater biomass and were therefore able to store more nutrients per unit area of wetland. In order to maximise the efficiency of constructed wetlands for nutrient removal, a range of species should be used. Native species should be selected in preference to introduced/exotic species.

Ibuprofen removal in horizontal subsurface flow constructed wetlands: treatment performance and fungal community dynamics.

Science.gov (United States)

Zhang, Dongqing; Luo, Jinxue; Lee, Zarraz May Ping; Gersberg, Richard M; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

2016-01-01

The treatment performance of ibuprofen (IBP)-enriched wastewater by horizontal subsurface flow constructed wetlands planted with cattail (Typha angustifolia) and unplanted control mesocosms was investigated. Removal efficiencies of IBP were significantly (p fungal community in these wetland systems. The overall diversity of the fungal community was reduced under the IBP exposure. Taxonomic analysis revealed that 62.2% of the fungal sequences were affiliated with Basidiomycota, followed by Ascomycota (37.4%) at the phylum level. Uncultured fungus (48.2%), Chaetomium sp. (14.2%), Aspergillus sp. (12.4%), Trichoderma sp. (5.7%), Cladosporium sp. (5.4%), and Emericellopsis sp. (5.2%) were identified as dominant genera. At the genus level, a distinct profile of the fungal community in the IBP-enriched mesocosms was observed as compared to the control beds, and as well specific fungal genera were enhanced in the planted beds, regardless of IBP enrichment. However, despite these differences, the composition of the fungal community (as measured by Bray-Curtis similarity) was mostly unaffected by the significant IBP enrichment. On the other hand, a consistent similarity pattern of fungal community structure in the planted mesocosms suggests that the presence of higher macrophytes in the wetland systems may well help shape the fungal community structure.

Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

Directory of Open Access Journals (Sweden)

Yang Zamin K

2010-05-01

Full Text Available Abstract Background Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. Results qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. Conclusions The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.

Absorption characteristics of compound heavy metals vanadium, chromium, and cadmium in water by emergent macrophytes and its combinations.

Science.gov (United States)

Lin, Hai; Liu, Junfei; Dong, Yingbo; Ren, Kaiqiang; Zhang, Yu

2018-04-20

The aim of the present study was to investigate three kinds of emergent macrophytes, i.e., Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb and their combination patterns on their removal efficiency of compound heavy metals (vanadium, chromium, and cadmium) from synthetic aqueous. The results showed that the optimal single-species for compound heavy metals removal was Acorus calamus L. and during experiment period, the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 52.4, 46.8, and 90.0%, respectively. Combination C (the quality ratio of Acorus calamus L., Phragmites communis Trin., and Alternanthera philoxeroides (Mart.) Griseb is 2:1:1) had the highest removal efficiency on compound heavy metals among three groups and the average removal efficiency of V 5+ , Cr 6+ , and Cd 2+ was 18.0, 70.0, and 95.1%, respectively. The highest efficiency of combination C on V 5+ removal was lower than single Alternanthera philoxeroides (Mart.) Griseb group; this may be an existing antagonism in different plants. Heavy metals of V 5+ , Cr 6+ , and Cd 2+ had an obviously positive effect on SOD, CAT, and POD of emergent macrophytes. From these results, we conclude that in a phytoremediation for the removal of compound heavy metals where V was dominated pollution in water, the use of Acorus calamus L. species rather than a mixture of several plants should be suggested. When heavy metal pollution was dominated by Cr and Cd, group C rather than a single plant species should be used.

Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

Science.gov (United States)

Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

2013-05-01

Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

Core Community Specifications for Electron Microprobe Operating Systems: Software, Quality Control, and Data Management Issues

Science.gov (United States)

Fournelle, John; Carpenter, Paul

2006-01-01

Modem electron microprobe systems have become increasingly sophisticated. These systems utilize either UNIX or PC computer systems for measurement, automation, and data reduction. These systems have undergone major improvements in processing, storage, display, and communications, due to increased capabilities of hardware and software. Instrument specifications are typically utilized at the time of purchase and concentrate on hardware performance. The microanalysis community includes analysts, researchers, software developers, and manufacturers, who could benefit from exchange of ideas and the ultimate development of core community specifications (CCS) for hardware and software components of microprobe instrumentation and operating systems.

Influence of Bicarbonate, Sulfate, and Electron Donors on Biological reduction of Uranium and Microbial Community Composition

Energy Technology Data Exchange (ETDEWEB)

Luo, Wensui [ORNL; Zhou, Jizhong [ORNL; Wu, Weimin [ORNL; Yan, Tingfen [ORNL; Criddle, Craig [ORNL; Jardine, Philip M [ORNL; Gu, Baohua [ORNL

2007-01-01

A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 mM or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and geoundwater geochemistry alter microbial communities responsible for U(VI) reduction.

Influence of bicarbonate, sulfate, and electron donors on biological reduction of uranium and microbial community composition

Energy Technology Data Exchange (ETDEWEB)

Luo Wensui [Oak Ridge Inst. for Science and Education, TN (United States); Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Wu Wei-Min; Criddle, C.S. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; Yan Tingfen [Oak Ridge Inst. for Science and Education, TN (United States); Jardine, P.M.; Gu Baohua [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Zhou Jizhong [Oklahoma Univ., Norman, OK (United States). Dept. of Botany and Microbiology

2007-12-15

A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low-bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high-bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and groundwater geochemistry alter microbial communities responsible for U(VI) reduction. (orig.)

The role of macrophytes in habitat structuring in aquatic ecosystems: methods of measurement, causes and consequences on animal assemblages' composition and biodiversity O papel das macrófitas na estruturação de habitat em ambientes aquáticos: métodos de medida, causas e consequências para a composição das assembléias animais e biodiversidade

Directory of Open Access Journals (Sweden)

Sidinei Magela Thomaz

2010-06-01

Full Text Available Aquatic macrophytes play an important role in structuring communities in aquatic environments. These plants provide physical structure, increase habitat complexity and heterogeneity and affect various organisms like invertebrates, fishes and waterbirds. The complexity provided by macrophytes has been exhaustively studied in aquatic environments. However, macrophyte complexity has rarely been measured in a standardized fashion, making comparisons among different studies and the establishment of general conclusions difficult. To address this issue, this review is focused on questions related to the habitat structural complexity provided by these plants, exploring: i how complexity has been viewed by ecologists, with an emphasis on macrophyte studies; ii the pros and cons of several methods used to quantify plant complexity; iii the consequences of habitat structuring by macrophytes on invertebrates and fish and possible causes, mediated by habitat complexity, that lead to changes in these animal assemblages; iv potential impacts of non-native macrophyte species on habitat complexity and v the importance of complexity provided by macrophytes to management strategies for maintaining aquatic biodiversity. We examined literature produced in both temperate and tropical regions, but prioritized the latter. We found a great variety of habitat complexity measurements that are applied to aquatic macrophytes to understand their influence on attached animal assemblages. A lack of standardization (considering the wide range of techniques and scales of resolution used limits comparisons between different studies exploring this subject, in which biological samples and physical substrates were used to explore these relationships. Macrophytes affect animal assemblages and promote biodiversity through a chain of mechanisms, related to habitat complexity, that involve the availability of shelter and feeding sites. Invasive macrophyte species may modify habitat

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...... and distributional patterns corresponded well with the long-term (weeks) results obtained, but with some important deviations. The long-term responses of the two species to low temperature (12 °C) were more similar than expected. In contrast, high temperature (35 °C), which stimulated photosynthesis in C. submersum...... in the short term, inhibited photosynthesis in the long term and resulted in lower growth rates of C. submersum, both compared to C. demersum and to growth rates at intermediate temperatures (18 and 25 °C). 3. The long-term acclimation strategy differed between the two species. Ceratophyllum demersum achieved...

Phenol toxicity to the aquatic macrophyte Lemna paucicostata

Energy Technology Data Exchange (ETDEWEB)

Park, Ji-Sook [Division of Life Science, University of Incheon, Incheon 406-840 (Korea, Republic of); Brown, Murray T. [School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon PL4 8AA (United Kingdom); Han, Taejun, E-mail: hanalgae@hanmail.net [Division of Life Science, University of Incheon, Incheon 406-840 (Korea, Republic of); Institute of Green Environmental Research, University of Incheon, Incheon 406-840 (Korea, Republic of)

2012-01-15

Phenol is a ubiquitous environmental pollutant and a widely used reference toxicant for many bioassays. However, little information is available regarding the toxic effects of phenol on aquatic macrophytes. Seventy-two hour bioassays, with different end-points, were carried out to assess phenol toxicity in Lemna paucicostata. A concentration-dependent decline in frond multiplication and colony disintegration was observed, with 11.38 and 22.76 {mu}M phenol resulting in browning of fronds and colony disintegration, respectively. Growth of fronds, as measured by changes in surface area, was significantly inhibited with EC{sub 50} value of 2.70 {mu}M. When pulse amplitude modulated chlorophyll a (Chl a) fluorescence imaging (i-PAM) was employed, the maximum quantum yield of PS II (F{sub v}/F{sub m}) significantly declined with increasing phenol concentrations with resultant EC{sub 50} of 1.91 {mu}M and coefficients of variation (CVs) generated for the EC{sub 50} values of less than 4.7%. A gradual increase in fluorescence emissions from chlorophylls a and b and pheophytin up to a concentration of 2.85 {mu}M was found but declined markedly at higher concentrations. The significant correlation between the F{sub v}/F{sub m} and surface growth rate data implies that the former is an appropriate biomarker of whole plant toxicity. Using imaging Chl a fluorescence on L. paucicostata provides a rapid, sensitive and reliable method for assessing the toxic risks posed by phenol to aquatic ecosystems and has practical applications for municipal and industrial waste water management.

Phenol toxicity to the aquatic macrophyte Lemna paucicostata

International Nuclear Information System (INIS)

Park, Ji-Sook; Brown, Murray T.; Han, Taejun

2012-01-01

Phenol is a ubiquitous environmental pollutant and a widely used reference toxicant for many bioassays. However, little information is available regarding the toxic effects of phenol on aquatic macrophytes. Seventy-two hour bioassays, with different end-points, were carried out to assess phenol toxicity in Lemna paucicostata. A concentration-dependent decline in frond multiplication and colony disintegration was observed, with 11.38 and 22.76 μM phenol resulting in browning of fronds and colony disintegration, respectively. Growth of fronds, as measured by changes in surface area, was significantly inhibited with EC 50 value of 2.70 μM. When pulse amplitude modulated chlorophyll a (Chl a) fluorescence imaging (i-PAM) was employed, the maximum quantum yield of PS II (F v /F m ) significantly declined with increasing phenol concentrations with resultant EC 50 of 1.91 μM and coefficients of variation (CVs) generated for the EC 50 values of less than 4.7%. A gradual increase in fluorescence emissions from chlorophylls a and b and pheophytin up to a concentration of 2.85 μM was found but declined markedly at higher concentrations. The significant correlation between the F v /F m and surface growth rate data implies that the former is an appropriate biomarker of whole plant toxicity. Using imaging Chl a fluorescence on L. paucicostata provides a rapid, sensitive and reliable method for assessing the toxic risks posed by phenol to aquatic ecosystems and has practical applications for municipal and industrial waste water management.

Temporal variations in methane emissions from emergent aquatic macrophytes in two boreonemoral lakes.

Science.gov (United States)

Milberg, Per; Törnqvist, Lina; Westerberg, Lars M; Bastviken, David

2017-07-01

Methane (CH 4 ) emissions via emergent aquatic macrophytes can contribute substantially to the global CH 4 balance. We addressed temporal variability in CH 4 flux by using the static chamber approach to quantify fluxes from plots dominated by two species considered to differ in flux transport mechanisms ( Phragmites australis , Carex rostrata ). Temporal variability in daily mean emissions from early June to early October was substantial. The variable that best explained this variation was air temperature. Regular and consistent diel changes were absent and therefore less relevant to include when estimating or modelling CH 4 emissions. Methane emissions per m 2 from nearby plots were similar for Phragmites australis and Carex rostrata indicating that CH 4 production in the system influenced emissions more than the species identity. This study indicates that previously observed diel patterns and species-effects on emissions require further evaluation to support improved local and regional CH 4 flux assessments.

The Need Of A Phenological Spectral Library Of Submersed Macrophytes For Lake Monitoring

Science.gov (United States)

Wolf, Patrick; Robler, Sebastian; Schneider, Thomas; Melzer, Arnulf

2013-12-01

Submersed macrophytes are bio-indicators for water quality. For plant monitoring by remote sensing, in-situ reflectance measurements are necessary. Hence, systematic measurements were carried out at Lake Starnberg and Lake Tegernsee (Germany) in the year 2011. Besides two wide-spread species (Chara spp. and Potamogeton perfoliatus), the invasive species Elodea nuttallii and Najas marina were investigated. Remote sensing reflectances were calculated from downwelling irradiance and upwelling radiance. Those were collected with RAMSES spectroradiometers (320nm-950nm, 3.3nm step). As data collection took place several times, changes in the spectral responses within the growing season were detected and could be linked to population density, growing height, biomass and pigmentation. Additionally, a stable sampling method and a processing chain for the in-situ reflectance measurements were developed. Part of the processing was a water column correction, including WASI (water colour simulator). Principal component analysis showed separability of sediment from vegetation and species differentiation.

Metal concentrations in aquatic macrophytes as influenced by soil and acidification

Science.gov (United States)

Sparling, D.W.; Lowe, T.P.

1998-01-01

Bioavailability of metals to aquatic plants is dependent on many factors including ambient metal concentration, pH of soil or water, concentration of ligands, competition with other metals for binding sites, and mode of exposure. Plants may be exposed to metals through water, air, or soil, depending on growth form. This paper examines the influence of soil type under two regimens of water acidification on metal uptake by four species of aquatic macrophytes: smartweed (Polygonum sagittatum), burreed (Sparganium americanum), pondweed (Potamogeton diversifolius), and bladderwort (Utricularia vulgaris) in constructed, experimentally acidified wetlands. Soil types consisted of a comparatively high-metal clay or a lower-metal sandy loam. Each pond was either acidified to pH ca. 4.85.3 or allowed to remain circumneutral. Metal concentrations tended to be higher in the submerged bladderwort and pondweed than in the emergent burreed and smartweed. Soils were important to plant metal concentrations in all species, but especially in the emergents. Acidification influenced plant concentrations of some metals and was especially important in the submerged pondweed. Bioaccumulation of metals occurred for Mn, B, Sr, Ba, and Zn, compared to soil concentrations.

The Influence of Macrophytes on Sediment Resuspension and the Effect of Associated Nutrients in a Shallow and Large Lake (Lake Taihu, China)

Science.gov (United States)

Zhu, Mengyuan; Zhu, Guangwei; Nurminen, Leena; Wu, Tingfeng; Deng, Jianming; Zhang, Yunlin; Qin, Boqiang; Ventelä, Anne-Mari

2015-01-01

A yearlong campaign to examine sediment resuspension was conducted in large, shallow and eutrophic Lake Taihu, China, to investigate the influence of vegetation on sediment resuspension and its nutrient effects. The study was conducted at 6 sites located in both phytoplankton-dominated zone and macrophyte-dominated zone of the lake, lasting for a total of 13 months, with collections made at two-week intervals. Sediment resuspension in Taihu, with a two-week high average rate of 1771 g·m-2·d-1 and a yearly average rate of 377 g·m-2·d-1, is much stronger than in many other lakes worldwide, as Taihu is quite shallow and contains a long fetch. The occurrence of macrophytes, however, provided quite strong abatement of sediment resuspension, which may reduce the sediment resuspension rate up to 29-fold. The contribution of nitrogen and phosphorus to the water column from sediment resuspension was estimated as 0.34 mg·L-1 and 0.051 mg·L-1 in the phytoplankton-dominated zone. Sediment resuspension also largely reduced transparency and then stimulated phytoplankton growth. Therefore, sediment resuspension may be one of the most important factors delaying the recovery of eutrophic Lake Taihu, and the influence of sediment resuspension on water quality must also be taken into account by the lake managers when they determine the restoration target. PMID:26030094

Community-based blood pressure measurement by non-health workers using electronic devices: a validation study

Directory of Open Access Journals (Sweden)

Daniel D. Reidpath

2012-06-01

Full Text Available Introduction: Population monitoring and screening of blood pressure is an important part of any population health strategy. Qualified health workers are expensive and often unavailable for screening. Non-health workers with electronic blood pressure monitors are increasingly used in community-based research. This approach is unvalidated. In a poor, urban community we compared blood pressure measurements taken by non-health workers using electronic devices against qualified health workers using mercury sphygmomanometers. Method: Fifty-six adult volunteers participated in the research. Data were collected by five qualified health workers, and six non-health workers. Participants were randomly allocated to have their blood pressure measured on four consecutive occasions by alternating a qualified health worker with a non-health worker. Descriptive statistics and graphs, and mixed effects linear models to account for the repeated measurement were used in the analysis. Results: Blood pressure readings by non-health workers were more reliable than those taken by qualified health workers. There was no significant difference between the readings taken by qualified health workers and those taken by non-health workers for systolic blood pressure. Non-health workers were, on average, 5–7 mmHg lower in their measures of blood pressure than the qualified health workers (95%HPD: −2.9 to −10.0 for diastolic blood pressure. Conclusion: The results provide empirical evidence that supports the practice of non-health workers using electronic devices for BP measurement in community-based research and screening. Non-health workers recorded blood pressures that differed from qualified health workers by no more than 10 mmHg. The approach is promising, but more research is needed to establish the generalisability of the results.

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.

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.

Influence of inlet water on the biotic and abiotic variables in a fish pond

Directory of Open Access Journals (Sweden)

L. H. Sipaúba-Tavares

Full Text Available Abstract The effects of treated and untreated water inlets with macrophytes on the improvement of water quality and zooplankton community were evaluated in a fish pond with continuous water flow. Water and zooplankton samples were retrieved at four sites during nine months. There were differences (p<0.01 between inlet water from fish pond and inlet water from canal with macrophytes, featuring higher concentrations of nutrient load, mainly TAN and TP in the former. The inlet water from fish pond contained a higher number of abundant species (9 species, whilst the water supply from the canal with macrophytes had a greater richness (31 species of zooplankton species. Results showed that inlet water without macrophytes directly affected the characteristics of the water column and the dominance of zooplankton species such as Thermocyclops decipiens, and greater abundance of Rotifera species. Since aquatic plants in the inlet water of fish pond analyzed showed lower allochthonous material loads from the previous fish pond, the management adopted with macrophytes may be applied to avoid eutrophication risks, common in farm ponds.

Comparative Evaluation of Anaerobic Bacterial Communities Associated with Roots of Submerged Macrophytes Growing in Marine or Brackish Water Sediments

Science.gov (United States)

Sediment microbial communities are important for seagrass growth and carbon cycling, however relatively few studies have addressed the composition of prokaryotic communities in seagrass bed sediments. Selective media were used enumerate culturable anaerobic bacteria associated ...

"Community vital signs": incorporating geocoded social determinants into electronic records to promote patient and population health.

Science.gov (United States)

Bazemore, Andrew W; Cottrell, Erika K; Gold, Rachel; Hughes, Lauren S; Phillips, Robert L; Angier, Heather; Burdick, Timothy E; Carrozza, Mark A; DeVoe, Jennifer E

2016-03-01

Social determinants of health significantly impact morbidity and mortality; however, physicians lack ready access to this information in patient care and population management. Just as traditional vital signs give providers a biometric assessment of any patient, "community vital signs" (Community VS) can provide an aggregated overview of the social and environmental factors impacting patient health. Knowing Community VS could inform clinical recommendations for individual patients, facilitate referrals to community services, and expand understanding of factors impacting treatment adherence and health outcomes. This information could also help care teams target disease prevention initiatives and other health improvement efforts for clinic panels and populations. Given the proliferation of big data, geospatial technologies, and democratization of data, the time has come to integrate Community VS into the electronic health record (EHR). Here, the authors describe (i) historical precedent for this concept, (ii) opportunities to expand upon these historical foundations, and (iii) a novel approach to EHR integration. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Public Health Community Platform, Electronic Case Reporting, and the Digital Bridge.

Science.gov (United States)

Cooney, Mary Ann; Iademarco, Michael F; Huang, Monica; MacKenzie, William R; Davidson, Arthur J

At the intersection of new technology advancements, ever-changing health policy, and fiscal constraints, public health agencies seek to leverage modern technical innovations and benefit from a more comprehensive and cooperative approach to transforming public health, health care, and other data into action. State health agencies recognized a way to advance population health was to integrate public health with clinical health data through electronic infectious disease case reporting. The Public Health Community Platform (PHCP) concept of bidirectional data flow and knowledge management became the foundation to build a cloud-based system connecting electronic health records to public health data for a select initial set of notifiable conditions. With challenges faced and lessons learned, significant progress was made and the PHCP grew into the Digital Bridge, a national governance model for systems change, bringing together software vendors, public health, and health care. As the model and technology advance together, opportunities to advance future connectivity solutions for both health care and public health will emerge.

Change of trace elements content in sewage water under the influence of hydrophilic macrophytes

International Nuclear Information System (INIS)

Akhmed-Ogly, K V; Savichev, O G

2014-01-01

According to the researches carried out by authors in 2013, the estimate of the effectiveness of domestic sewage treatment with the help of hydrophilic vegetation was received. It has been shown that if sewage is treated with the help of macrophytes, copper and lead concentration reduces. Thus, if the volume of sewage treated by reed mace is 500 ml and 1 l, lead concentration decreases 5 and 3,5 times, if sewage is treated by reed, lead concentration decreases 2,5 times in both cases; if sewage is treated by reed mace copper concentration decreases 0,9 and 1,8 times (if the volume of sewage is 500 ml and 1 l), if sewage is treated by reed, copper concentration decreases 1,4 and 1,5 times respectively. The conclusion has been drawn: in West Siberia it is possible to use the shallow reservoirs with natural aeration and hydrophilic vegetation for effective sewage treatment from such heavy metals as lead and copper

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.

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.

A continuous-flow system for measuring in vitro oxygen and nitrogen metabolism in separated stream communities

DEFF Research Database (Denmark)

Prahl, C.; Jeppesen, E.; Sand-Jensen, Kaj

1991-01-01

on the stream bank, consists of several macrophyte and sediment chambers equipped with a double-flow system that ensures an internal water velocity close to that in the stream and which, by continuously renewing the water, mimics diel fluctuation in stream temperature and water chemistry. Water temperature...... production and dark respiration occurred at similar rates (6-7g O2 m-2 day-1), net balance being about zero. Inorganic nitrogen was consumed both by the sediment and to a greater extent by the macrophytes, the diel average consumption being 1g N m-2 day-1. 3. The sum of the activity in the macrophyte...... and sediment chambers corresponded to the overall activity of the stream section as determined by upstream/downstream mass balance. This indicates that the results obtained with the continuous-flow chambers realistically describe the oxygen and the nitrogen metabolism of the stream....

Isolation and identification of a phytotoxic substance from the emergent macrophyte Centrostachys aquatica.

Science.gov (United States)

Bich, Tran Thi Ngoc; Kato-Noguchi, Hisashi

2014-12-01

Centrostachys aquatica is a perennial emergent macrophyte in marshy places and in rivers. The species was recorded in Senegal and Nigeria, but widespread in tropical Africa, and South and East Asia. Aqueous methanol extracts C. aquatica was found to be toxic to several plant species. However, no phytotoxic substance has been reported in this species. Therefore, we investigated phytotoxic activity and searched for phytotoxic substances with allelopathic activity in C. aquatica. An aqueous methanol extract of C. aquatica inhibited the growth of roots and hypocotyls of cress (Lepidium sativum). The extract was then purified by several chromatographic runs and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as loliolide. Loliolide inhibited cress root and hypocotyl growth at concentrations greater than 0.03 μM. The concentrations required for 50% growth inhibition of cress roots and hypocotyls was 0.18 and 0.15 μM, respectively. These results suggest that loliolide is a phytotoxic substance and may contribute to the allelopathic effect caused by C. aquatica.

Foliar uptake of 137Cs from the water column by aquatic macrophytes

International Nuclear Information System (INIS)

Kelly, M.S.; Pinder, J.E. III

1996-01-01

A transplant experiment was performed to determine the relative importances of root uptake from the sediments and foliar uptake from the water column in determining the accumulation of 137 Cs by aquatic macrophytes. Uncontaminated individuals of three species, Brasenia schreberi, Nymphaea odorata and Nymphoides cordata, were transplanted into pots containing either contaminated sediments (i.e. 1.2 Bq 137 Cs g -1 dry mass) or uncontaminated sediments (i.e. -1 dry mass) and immersed in Pond B, a former reactor cooling pond where 137 Cs concentrations in surface waters range from 0.4 to 0.8 Bq liter -1 . The plants is uncontaminated sediments rapidly accumulated 137 Cs from the water column and after 35 days of immersion had 137 Cs concentrations in leaves that were: (1) not statistically significantly different from those for plants in contaminated sediments; and (2) similar to those for the same species growing naturally in Pond B. The similarity in 137 Cs concentrations between naturally-occurring plants and those in pots with uncontaminated sediments suggests that foliar uptake from the water column is the principal mode of Cs accumulation by these species in Pond B. (author)

Oxidative stress mediated toxicity of TiO2 nanoparticles after a concentration and time dependent exposure of the aquatic macrophyte Hydrilla verticillata.

Science.gov (United States)

Spengler, Annette; Wanninger, Lena; Pflugmacher, Stephan

2017-09-01

The present study focused on oxidative stress effects in the aquatic macrophyte Hydrilla verticillata after exposure to titanium dioxide nanoparticles (TiO 2 -NPs). Experiments were conducted with different TiO 2 -NPs and concentrations (0.1 mg/L and 10 mg/L) in a time-dependent manner (0 h, 24 h, 48 h, 96 h, 168 h). To assess various levels of the oxidative stress response in H. verticillata, the level of hydrogen peroxide (H 2 O 2 ), the ratio of reduced to oxidized glutathione (GSH/GSSG), and activities of the antioxidative enzymes catalase (CAT) and glutathione reductase (GR) were evaluated. Study results imply oxidative stress effects after TiO 2 -NP exposure as adaptations in plant metabolism became apparent to counteract increased ROS formation. All TiO 2 -NPs caused elevated activities of the enzymes CAT and GR. Moreover, decreased ratios of GSH/GSSG indicated an activation of GSH-dependent pathways counteracting ROS formation. Plants exposed to a bulk-sized control revealed a size-dependent influence on the antioxidative stress response. As H 2 O 2 level increases were solely detected after exposure to 10 mg/L TiO 2 -NPs and nano-exposed plants showed normalization in its antioxidative stress response after 168h of exposure, it can be suggested that macrophytes are able to cope with currently predicted low-level exposures to TiO 2 -NPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Establishing Functional Relationships between Abiotic Environment, Macrophyte Coverage, Resource Gradients and the Distribution of Mytilus trossulus in a Brackish Non-Tidal Environment.

Directory of Open Access Journals (Sweden)

Jonne Kotta

Full Text Available Benthic suspension feeding mussels are an important functional guild in coastal and estuarine ecosystems. To date we lack information on how various environmental gradients and biotic interactions separately and interactively shape the distribution patterns of mussels in non-tidal environments. Opposing to tidal environments, mussels inhabit solely subtidal zone in non-tidal waterbodies and, thereby, driving factors for mussel populations are expected to differ from the tidal areas. In the present study, we used the boosted regression tree modelling (BRT, an ensemble method for statistical techniques and machine learning, in order to explain the distribution and biomass of the suspension feeding mussel Mytilus trossulus in the non-tidal Baltic Sea. BRT models suggested that (1 distribution patterns of M. trossulus are largely driven by separate effects of direct environmental gradients and partly by interactive effects of resource gradients with direct environmental gradients. (2 Within its suitable habitat range, however, resource gradients had an important role in shaping the biomass distribution of M. trossulus. (3 Contrary to tidal areas, mussels were not competitively superior over macrophytes with patterns indicating either facilitative interactions between mussels and macrophytes or co-variance due to common stressor. To conclude, direct environmental gradients seem to define the distribution pattern of M. trossulus, and within the favourable distribution range, resource gradients in interaction with direct environmental gradients are expected to set the biomass level of mussels.

Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes.

Science.gov (United States)

Ren, Ge; Ma, Anzhou; Zhang, Yanfen; Deng, Ye; Zheng, Guodong; Zhuang, Xuliang; Zhuang, Guoqiang; Fortin, Danielle

2018-04-06

Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane-cycling microbes and their partners being observed in the iron/sulfate-rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane-rich environments. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Characterization of water quality and biological communities, Fish Creek, Teton County, Wyoming, 2007-2011