Macrophytes Research Papers - Academia.edu (original) (raw)

Total mercury (T-Hg) and organic mercury (mainly methylmercury, MeHg) concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish) of the shallow and eutrophic Lake Candia (Turin, Northern Italy) were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 µg kg -1 d.w.), zooplankton (77 µg kg -1 d.w.), Unio pictorum mancus (37.9 µg kg -1 d.w.), macrophytes (28.9 µg kg -1 d.w.). The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 µg m -2 . The importance of mercury biomagnification is also discussed.

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- Limnology, Multidisciplinary, Macrophytes, FISH

Paleoenvironmental reconstruction combining data from diatom, pollen, macrophytic, and archaeological analyses had not been attempted previously for coastal Peru. We analyzed two radiocarbondated sediment cores extracted from the "sacred" Urpi Kocha Lagoon at the pre-Hispanic religious center of Pachacamac (ca. AD 350e1533), near Lima, to characterize the paleoenvironment of the site. The data reveal an environmental history characterized by alternating periods of severe drought and catastrophic flood. Recurrent pulses with distinctive sediment, diatom, pollen, and macrophytic characteristics reflecting variations in water depth, substrate, turbidity and salinity, usually contain a thick basal sandy storm deposit overlain by thin organic accumulations of peat, gyttja, and snails. The most intense of these disturbance pulses, when correlated with pollen, plant macrofossils, radiocarbon dates, and regional proxy data, provide local evidence of four major floods associated with sustained, catastrophic El Niño events, tsunamis and/or severe storms in the Andean highlands over the last 2000 years.

- by Lee Ann Newsom
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- Archaeology, Geochemistry, Archaeological Science, Paleoecology

The main aim of this study, which is based on cover-abundance values of 20 species of floatingleaved and submersed macrophytes collected in 18 lakes located within the River Po catchment basin (Italy), is to investigate the relationships between lake-scale environmental features (including morphology, hydrology, trophic state and water quality variables) and the changes in species composition and species richness in macrophyte communities. The findings reveal that the main changes in community composition of the pondweed communities, identified by principal component analysis, could be effectively explained by a newly introduced morpho-hydrological parameter (the theoretical laminar water renewal rate -R L ) and by the trophic state of the lakes, expressed as Carlson's trophic state index (TSI). The results of the multivariate analyses performed also show that the grouping of species is strictly related to growth-form traits. In particular, floating-leaved and submerged macrophytes appeared mutually exclusive in dominating different habitat types defined on the basis of the R L -TSI framework. An increasing trend in species richness was also observed in relation to R L . The possibility of using the bivariate R L -TSI framework for the identification of habitat utilisation patterns by single species was also investigated, and cover-abundance prediction maps based on the R L -TSI framework were produced for several macrophyte species. Observations in another system characterised by high spatial heterogeneity for hydrological and trophic conditions, support the predictions in terms of growth-form prevalence, species richness and single species cover-abundance (where available), and also suggest a more refined application of the proposed approach. Gaertn.; NLUT -Nuphar luteum L. Sibth & Sm; NALB -Nymphaaea alba L.; NPEL -Nymphoides peltata; PAMP -Polygonum amphybium L.; PCRI -Potamogeton crispus L.; PLUC -Potamogeton lucens L.; PPEC -Potamogeton pectinatus L.; PPER -Potamogeton perfoliatus L.; PPUS -Potamogeton pusillus L.; RTRI -Ranunculus trichophyllus Chaix;TNAT -Trapa natans L.; VSPI -Vallisneria spiralis L.; ZPAL -Zannichellia palustris L.

- by Alessandro Ludovisi
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- Earth Sciences, Water quality, Principal Component Analysis, Hydrobiology

Resumo -É apresentado o levantamento florístico de Cabombaceae do estado da Bahia, Brasil. Foram reconhecidas quatro espécies do gênero Cabomba: C. aquatica, C. caroliniana, C. furcata e C. haynesii. O tratamento inclui descrição dos táxons, além de chave de identificação, ilustrações e comentários para as espécies. Palavras-chave adicionais: Brasil, Cabomba, florística, plantas aquáticas, taxonomia.

- by Francisco de Assis R Santos
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- Aquatic botany, Aquatic Plants, Macrophytes, Aquatic Macrophytes

1. The effect of total nitrogen (TN) and phosphorus (TP) loading on trophic structure and water clarity was studied during summer in 24 field enclosures fixed in, and kept open to, the sediment in a shallow lake. The experiment involved a control treatment and five treatments to which nutrients were added: (i) high phosphorus, (ii) moderate nitrogen, (iii) high nitrogen, (iv) high phosphorus and moderate nitrogen and (v) high phosphorus and high nitrogen. To reduce zooplankton grazers, 1 + fish (Perca fluviatilis L.) were stocked in all enclosures at a density of 3.7 individuals m )2 . 2. With the addition of phosphorus, chlorophyll a and the total biovolume of phytoplankton rose significantly at moderate and high nitrogen. Cyanobacteria or chlorophytes dominated in all enclosures to which we added phosphorus as well as in the high nitrogen treatment, while cryptophytes dominated in the moderate nitrogen enclosures and the controls. 3. At the end of the experiment, the biomass of the submerged macrophytes Elodea canadensis and Potamogeton sp. was significantly lower in the dual treatments (TN, TP) than in single nutrient treatments and controls and the water clarity declined. The shift to a turbid state with low plant coverage occurred at TN >2 mg N L )1 and TP >0.13-0.2 mg P L )1 . These results concur with a survey of Danish shallow lakes, showing that high macrophyte coverage occurred only when summer mean TN was below 2 mg N L )1 , irrespective of the concentration of TP, which ranged between 0.03 and 1.2 mg P L )1 . 4. Zooplankton biomass and the zooplankton : phytoplankton biomass ratio, and probably also the grazing pressure on phytoplankton, remained overall low in all treatments, reflecting the high fish abundance chosen for the experiment. We saw no response to nutrition addition in total zooplankton biomass, indicating that the loss of plants and a shift to the turbid state did not result from changes in zooplankton grazing. Shading by phytoplankton and periphyton was probably the key factor. 5. Nitrogen may play a far more important role than previously appreciated in the loss of submerged macrophytes at increased nutrient loading and for the delay in the reestablishment of the nutrient loading reduction. We cannot yet specify, however, a

- by Erik Jeppesen
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- Freshwater Biology, Hydrobiology, Biological Sciences, Phosphorus

Wetlands are among the most productive ecosystem in the world, comparable to rain forest and coral reefs. They are repositories of diverse species of microbes, plants, insects, amphibians, reptiles and mammals. Wetlands are "Biological rearing heaven" which provide immense food that attract many animal species for completion of their life cycle. The present paper deals with an eco-taxonomic study of a wetland named "Chupisar", in short "Chupi" which lies in the proximity (23 о 32'882"N and 88 о 15'269"E) of the holy river Ganga (Ganges)

- by Mobina Parveen
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- Botany, Conservation Biology, Ecology, Macrophytes

Macrófitas flotantes en el tratamiento de aguas residuales: una revisión del estado del arte Floating macrophytes on the wastewater treatment: a state of the art review Macrófitas flutuantes no tratamento deáguas residuais: uma revisão do... more

The first aim of this invited literature review is critically to review and evaluate hydrological, physical and biochemical processes within natural and constructed wetlands. The second aim is to contribute the thoughts of the authors to the discussion with the help of a case study focusing on gully pot liquor treatment. The performances of constructed treatment wetlands with and without

- by Miklas Scholz
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- Environmental Studies, Water quality, Environmental Management, Multidisciplinary

The presence of macrophytes is one of the most conspicuous features of wetlands and their presence distinguishes constructed wetlands from unplanted soil filters or lagoons. The macrophytes growing in constructed wetlands have several properties in relation to the treatment process that make them an essential component of the design. However, only several roles of macrophytes apply to constructed wetlands with horizontal subsurface flow (HF CWs). The plants used in HF CWs designed for wastewater treatment should therefore: (1) be tolerant of high organic and nutrient loadings, (2) have rich belowground organs (i.e. roots and rhizomes) in order to provide substrate for attached bacteria and oxygenation (even very limited) of areas adjacent to roots and rhizomes and (3) have high aboveground biomass for winter insulation in cold and temperate regions and for nutrient removal via harvesting. The comparison of treatment efficiency of vegetated HF CWs and unplanted filters is not unanimous but most studies have shown that systems with plants achieve higher treatment efficiency. The vegetation has mostly a positive effect, i.e. supports higher treatment efficiency, for organics and nutrients like nitrogen and phosphorus. By far the most frequently used plant around the globe is Phragmites australis (Common reed). Species of the genera Typha (latifolia, angustifolia, domingensis, orientalis and glauca) and Scirpus (e.g. lacustris, validus, californicus and acutus) spp. are other commonly used species. In many countries, and especially in the tropics and subtropics, local plants including ornamental species are used for HF CWs.

- by J. Vymazal
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- Earth Sciences, Wastewater Treatment, Biological Sciences, Phosphorus

This paper critically reviews the published works on lake restoration in north-western Europe, with the aim to highlight the causes of failures of lake biomanipulation, and to identify the main bottlenecks that have impeded progress. More importantly, we explore the prospects of applying new ecotechnological measures to lakes with a focus on shallow lakes. These complementary measures are: (1) reduction of sediment resuspension; (2) water-level management; and (3) the use in shallow lakes of bivalves as effective grazers on lake seston, especially when cyanobacteria are dominant. If the sustainability of the positive effects of biomanipulation is considered over a decade, there are probably more cases of failures than successes. The failures can be ascribed to several bottlenecks that include: (1) inadequate reduction of allochthonous phosphorus (P) and an increase in autochthonous P inputs, i.e. release of P from the lake sediments following reductions of external P inputs; (2) poor edibility of filamentous and colonial cyanobacteria to daphnids; (3) inadequate coverage of the lake area by macrophytes partly due to foraging on the macrophytes by both fish and birds; (4) ineffective reduction of planktivorous fish biomass and our inability to maintain the fish mass to a 'low level' for longer periods; and (5) failure of northern pike (Esox lucius) after its transplantation to the lakes to develop a population level that can control planktivorous fish to desired low levels. Three potentially complementary ecotechnological measures are discussed. The first such measure concerns prevention of sediment resuspension in lakes by creating islands in order to minimise the wind fetch to reduce the wave amplitude. The second measure involves allowing greater water-level fluctuations (WLF) in lakes as planned in lowland countries like the Netherlands; WLF are likely to allow more space for water, and may lead to improved water quality and higher biodiversity. The third ecotechnological measure relates to grazer populations that complement herbivorous zooplankton to regulate phytoplankton, particularly to control cyanobacterial blooms. For this, the bivalve Dreissena polymorpha appears to be a good potential candidate for grazing on phytoplankton, especially in shallow eutrophic lakes that are dominated by filamentous and toxic cyanobacteria (e.g. Planktothrix agardhii and Microcystis aeruginosa).

- by Ellen Donk
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- Western Europe, Water quality, Ecology, Phosphorus

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 structure and thus influence associated organisms. In this sense, they are suitable as the main focus of management strategies aimed at biodiversity restoration and conservation.

- by Eduardo R Cunha and +1
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- Diversity, Fractals, Macrophytes, Habitat complexity

This study in Lake Iro was focused on estimating macrophytic diversity, identifying plant groups, assessing potential threats to this vegetation, and determining the physico-chemical composition of water. Vegetation analysis was done by transect technology and plant group typology by the Braun-blanquetiste phytosociological method. The estimation of various diversity indices and the discrimination of different plant groups were made using the PAST software. Several materials were used to determine water quality. There were 30 species distributed among 21 genera and 12 families, of which 96,42% were Angiosperms and 3,58% were Pteridophytes. The best represented families were Poaceae, Fabaceae and Cyperaceae. The most frequent and present species on almost all transects were : Echinochloa colona, Echinochloa stagnina, Neptunia oleracea, Ceratophyllum demersum and Pistia stratioites. There were 6 groupings, some of which can be integrated into existing syntaxons in other lake ecosystems. Water quality was generally favorable to the development of aquatic species, but often polluted in areas of high frequency. Pressures on Lake Iro’s phytocenosis indicate the vulnerability of this ecosystem.

- by European Scientific Journal ESJ
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- Plant Ecology, Floristics, Macrophytes

SUMMARY 1. In some shallow lakes, Daphnia and other important pelagic consumers of phytoplankton undergo diel horizontal migration (DHM) into macrophytes or other structures in the littoral zone. Some authors have suggested that DHM reduces predation by fishes on Daphnia and other cladocerans, resulting in a lower phytoplankton biomass in shallow lakes than would occur without DHM. The costs and benefits of DHM, and its potential implications in biomanipulation, are relatively unknown, however. 2. In this review, we compare studies ...

- by Erik Jeppesen
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- Crustacea, Freshwater Biology, Biological Sciences, Environmental Sciences

Data on aquatic and emergent vegetation, morphology and water quality from 274 Polish lowland lakes surveyed in the years 1996-2009 were used to validate the preliminary typology of Polish lakes based on macrophytes and to indicate the environmental parameters which most significantly determine the vegetation patterns in lakes under various morphological conditions. In highly alkaline lowland lakes representing non-disturbed conditions the key determinants influencing the vegetation patterns were mean depth and the shape of the littoral. Three morphological lake types were distinguished: shallow (<3.5 m), deep, and additionally, within the latter, deep ribbon-shaped, with a clearly elongated base and steep bed slopes. The lake types varied in their vegetation patterns developed under non-disturbed conditions. In the shallow lakes, the share of the phytolittoral in the total lake area (%phytol) was the highest (40-100%, 72.3% on average) and the maximum colonisation depth (C max ) the lowest (3.2 m as the maximum) compared to the lakes from both deep types. In the ribbon-shaped deep lakes, %phytol and the plant coverage (%cover) were the lowest, the proportion of submerged vegetation was extraordinarily high (over 90%) and the emergent vegetation was extremely sparsely developed (<6%) compared to the lakes of the two other types.

- by Agnieszka Kolada
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- Typology, Biological Sciences, Environmental Sciences, Macrophytes

THE AQUATIC MACROPHYTE Ceratophyllum demersum IMMOBILIZES Au NANOPARTICLES AFTER THEIR ADDITION TO WATER [aquatic higher plants, macrophytes, water purification, water treatment, biotechnology, nanomaterials, biosorption, gold];... more

- by Sergei Ostroumov
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- Biosorption, Aquatic Plants, Macrophytes, Gold Nanoparticles

The objective of the study was to evaluate the phytoremediation potential of three aquatic macrophytes (Commelina cyanea, Phragmites australis and Water Hyacinth (Eichhornia crassipes)) for treatment of municipal wastewater collected from Federal University of Technology, Akure (Nigeria). Laboratory scale of three constructed wetlands of dimensions 0.43 m x 0.93 m x 0.36 m in width, length and depth respectively, were developed to mimic natural conditions and was operated for a single experimental run with each macrophte at different retention time of 6, 9 and 12 days. These aquatic macrophytes were planted in separate ponds. Domestic wastewater from undergraduate students' hostel was introduced to the ponds. The raw wastewater sample and treated wastewater samples were analysed using standard laboratory methods for physical (Turbidity and Dissolved solids), chemical (pH, Nitrate, Nitrite, Phosphate, Sulphate Chemical Oxygen Demand and Biochemical Oxygen Demand) and bacteriological (Coliform bacteria) parameters. Results showed substantial diminutions in all parameters treated with the phytoremediators during the course of the study. Asides the three plants effectively removing Nitrate, Nitrite, phosphate and Sulphate pollutants, Phragmites australis gave the highest removal efciency for Phosphate (85.8%), Water hyacinth gave the highest removal efciency for pH (11.5%), Biochemical Oxygen Demand and Coliform bacteria and Commelina cyanea gave the highest removal efciency for turbidity (96.9%) and dissolved solids (82.9%) parameters of the domestic wastewater samples. The overall results of the phytoremediation studies indicate that the purication effectiveness of the three aquatic macrophytes were spontaneous, feasible and remarkable.

1. Submerged plant richness is a key element in determining the ecological quality of freshwater systems; it has often been reduced or completely lost.2. The submerged and floating-leaved macrophyte communities of 60 shallow lakes in Poland and the U.K. have been surveyed and species richness related to environmental factors by general linearised models.3. Nitrogen, and more specifically winter nitrate, concentrations were most important in explaining species richness with which they were inversely correlated. Phosphorus was subsidiary. Such an inverse relationship is consistent with findings in terrestrial communities. Polish lakes, with less intensively farmed catchments, had greater richness than the U.K. lakes.4. The richest U.K. communities were associated with winter nitrate-N concentrations of up to about 1–2 mg L−1 and may correspond with ‘good’ ecological quality under the terms of the European Water Framework Directive. Current concentrations in European lowlands are often much higher.

- by Cassandra James
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- Management, Freshwater Biology, Agriculture, Eutrophication

This work focuses on an integrated approach for lake ecological status assessment, elaborated according to the requirements of the European Water Framework Directive (WFD). Data from five lowland and semi-mountain lakes in Bulgaria (Southeast Europe) collected from two years (2011-2012) form the basis for an integrated assessment and the definition of reference conditions. Several metrics were applied in combination, to classify lakes into five ecological status classes. Assemblages of aquatic organisms: phytoplankton, macrophytes and benthic macroinvertebrates, together with 11 supporting physico-chemical parameters were studied. The assessed unique conditions suggested that reference conditions of Bulgarian lakes have natural variability. This first baseline study illustrated specific cases within the lake types that should be assessed in details before providing standardized classification systems in compliance with the requirements of WFD.

- by Emilia Varadinova and +1
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- Macrophytes, Environmental protection

This article starts with a brief description of the origin and eutrophication of shallow Dutch lakes, followed by a review of the various lake restoration techniques in use and the results obtained. Most freshwater lakes in the Netherlands are very shallow (<2 m), and owe their origins to large-scale dredging and removal of peat during the early 17th century. They vary in area from a few hectares to a few thousand hectares, and are generally found in the northern and western part of the country. Most of them lie in the catchment areas of the major rivers: the Rhine, the Meuse and the Schelde. Because of their natural and aesthetic value, these lakes fulfil a recreational function. The lakes are important to the hydrology, water balance and agriculture in the surrounding polder country. The external input to the lakes of phosphorus (P) and nitrogen (N) and of polluted waters from the rivers and canals have been the major cause of eutrophication, which began during the 1950s. In addition, more recently climate changes, habitat fragmentation and biotic exploitation of many of these waters have probably led to loss of resilience and thus to accelerated eutrophication. Lake eutrophication is manifested essentially in the poor under-water light climate with high turbidity (Secchi-disc, 20-40 cm) caused usually by cyanobacterial blooms (e.g. Oscillatoria sp.), and loss of littoral vegetation. Despite recent perceptible reductions in external P inputs, non-point sources, especially of N from agriculture, still remain high and constitute a major challenge to the lake restorers. Lake recovery is also invariably afflicted by in-lake nutrient sources. These include P loading from the P-rich sediments, mineralization in the water and release by the foraging and metabolic activities of the abundant benthivorous and planktivorous fish, mainly bream (Abramis brama).

- by Ellen Donk
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- Earth Sciences, Climate Change, Water quality, Biological Sciences

Eutrophication constitutes a serious threat to many European lakes and many approaches have been used during the past 20-30 years to improve lake water quality. Results from the various lake restoration initiatives are diverse and the... more

- by Erik Jeppesen
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- Water quality, Ecology, Applied Ecology, Eutrophication

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

- by Kevin Wood
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- Botany, Zoology, Environmental Science, Ecosystems Ecology

Data on phytoplankton, macrophytes, ben-thic invertebrates and fish from more than 2000 lakes in 22 European countries were used to develop and test metrics for assessing the ecological status of European lakes as required by the Water Framework Directive. The strongest and most sensitive of the 11 metrics responding to eutrophication pressure were phyto-plankton chlorophyll a, a taxonomic composition trophic index and a functional traits index, the macrophyte intercalibration taxonomic composition metric and a Nordic lake fish index. Intermediate response was found for a cyanobacterial bloom intensity index (Cyano), the Ellenberg macrophyte index and a multimetric index for benthic invertebrates. The latter also responded to hydromorpholog-ical pressure. The metrics provide information on primary and secondary impacts of eutrophication in the pelagic and the littoral zone of lakes. Several of these metrics were used as common metrics in the intercalibration of national assessment systems or have been incorporated directly into the national systems. New biological metrics have been developed

- by Sandra Poikane
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- Aquatic Ecology, Phytoplankton Ecology, Ecology, Fish Ecology

Sewage treatment is posing serious techno-economic problems in cities, particularly in underdeveloped countries. A new technology, sewage purification by water hyacinth (Eichhornia crassipes), is a feasible solution. This paper studied the suitability and efficacy of water hyacinth in domestic sewage treatment. The study was carried out in the Department of Agricultural and Biosystems Engineering. Three treatments of water hyacinth replicated two times were used in the study. These treatments include no water hyacinth (control), 1kg and 2kg water hyacinth plant density cultures. The system was designed based on Completely Randomized Design (CRD). Sewage samples were collected during the growth of water hyacinth. Purification of water
hyacinth on sewage was rapid during the first three weeks in the sewage cultured with water hyacinth (especially 2kg water hyacinth plant density) and there was low absorption in nutrients in the last two weeks when attaining maturity. Parameters such as Cl-, Fe, Cu, Mn, Pb, K, F-, Nitrate and Sulphate were drastically reduced from 9mg/l to 3.33 mg/l, 1.25 mg/l to 0.36 mg/l, 0.3mg/l to 0 mg/l, 0.5mg/l to 0.08mg/l, 0.2mg/l to 0.01 mg/l, 1.7 mg/l to 0.17mg/l, 0.7 mg/l to 0.08mg/l, 8.6mg/l to 0.03mg/l, 17.5mg/l to 6.20 mg/l respectively throughout the course of the study. Also, the 2kg water hyacinth plant density cultured in the sewage purifies more compared to the 1kg water hyacinth plant density which is moderate and minimal in the control.

- by Fidelis O . AJIBADE and +1
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- Engineering, Environmental Engineering, Agricultural Engineering, Chemical Engineering

The species diversity and distribution of rotifers between different habitats (elodeids, helophytes and open water) of 34 field and 31 forest ponds, differing in regard to origin, size, depth, macrophyte cover, overshading and the... more

- by Natalia Kuczyńska-kippen
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- Ecology, Hydrobiology, Macrophytes, Community Structure
- by Iain Gunn
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- Botany, Plant Biology, Aquatic botany, Survey Methods

Multiple stressors to a shallow lake ecosystem have the ability to control the relative stability of alternative states (clear, macrophyte-dominated or turbid, algaldominated). As a consequence, the use of remedial biomanipulations to induce trophic cascades and shift a turbid lake to a clear state is often only a temporary solution. Here we show the instability of short-term manipulations in the shallow Lake Christina (Minnesota, USA) is governed by the long-term state following a regime shift in the lake. During the modern, managed period of the lake, three top-down manipulations (fish kills) were undertaken inducing temporary (5-10 years) unstable clear-water states. Paleoecological remains of diatoms, along with proxies of primary production (total chlorophyll a and total organic carbon accumulation rate) and trophic state (total P) from sediment records clearly show a single regime shift in the lake during the early 1950s; following this shift, the functioning of the lake ecosystem is dominated by a persistent turbid state. We find that multiple stressors contributed to the regime shift. First, the lake began to eutrophy (from agricultural land use and/or increased waterfowl populations), leading to a dramatic increase in primary production. Soon after, the construction of a dam in 1936 effectively doubled the depth of the lake, compounded by increases in regional humidity; this resulted in an increase in planktivorous and benthivorous fish reducing phytoplankton grazers. These factors further conspired to increase the stability of a turbid regime during the modern managed period, such that switches to a clear-water state were inherently unstable and the lake consistently returned to a turbid state. We conclude that while top-down manipulations have had measurable impacts on the lake state, they have not been effective in providing a return to an ecosystem similar to the stable historical period. Our work offers an example of a well-studied ecosystem forced by multiple stressors into a new long-term managed period, where manipulated clearwater states are temporary, managed features.

- by Thomas J.s Carlson
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- Paleolimnology, Biological Sciences, Lakes, Environmental Sciences

— The Total Petroleum Hydrocarbon (TPH) in the bottom sediments and aquatic macrophytes of the River Nun at AmasomaAxises was investigated in December, 2017. This was done to establish the existing levels of TPH in the River in order to ascertain the degree of its threat to the environment. Benthic samples were collected close to the shore with the aid of a hand trowel and put in aluminum foils, while macrophyte samples were collected by hand pulling and transported in plastic bags for laboratory analysis. Data were subjected to statistical analysis using the Microsoft Excell ® tool pack. Regression analysis was employed in order to determine the correlation between TPH in bottom sediments with that in plant tissues (leaf, stem and root). Analysis of variance was employed at the 95% confidence level to determine the degree of significance in interaction of TPH between sediments and macrophyte tissues and between macrophyte tissues (leaf, stem, and root). Duncan multiple range test was use to compare means. The bioaccumulation factor (BAF) was calculated for TPH in order to estimate the absorption rate of TPH between sediments and plant tissues (leaf, stem and root). Results indicate that TPH were recorded in sediments and plant tissues. TPH concentrations were greater in plant tissues than in sediments. Concentration of TPH showed concentrations indicating that root> stem> leaf in most stations. The relationships between the TPH attributes indicated strong association between Leaves and stem (r 2 = 0.92). Strong negative association was also observed between sediment and stem (r 2 =-0.83) while sediment and leaves (r 2 =-0.64) had moderate negative relationship. It can be concluded that the River Nun at AmasomaAxises is mildly polluted due to land based activities and therefore there is a need to enact water use regulatory ordinances to protect its ecology. Sediment organisms and plants are vital links to man in the food chain. This may portend danger in the future.

- by Agriculture Journal IJOEAR
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- Macrophytes, Sediments, Total Petroleum Hydrocarbon

"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 se identifican los antecedentes de mayor relevancia desde los inicios de esta aplicación. Serán descritos los modelos de diseño con macrófitas y los criterios generalmente aceptados, revisando rigurosamente las eficiencias de remoción de distintas especies de macrófitas flotantes. Por último serán abordadas según lo analizado las perspectivas actuales y retos futuros para el desarrollo de esta técnica"

- by Revista Ingeniería y Ciencia and +2
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- Macrophytes and heavy metal phytoremediation, Water and wastewater treatment, Biology, Water Treatment
- by Ana Picado
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- Ecotoxicology, Wastewater Treatment, Macrophytes

Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International Symposium on Aquatic Plants, held in Edinburgh in September 2015, brought together 120 delegates from 28 countries and six continents. This special issue of Hydrobiologia includes a select number of papers on aspects of aquatic plants, covering a wide range of species, systems and issues. In this paper, we present an overview of current trends and future directions in aquatic plant research in the early twenty first century. Our understanding of aquatic plant biology, the range of scientific issues being addressed and the range of techniques available to researchers have all arguably never been greater; however, substantial challenges exist to the conservation and management of both aquatic plants and the ecosystems in which they are found. The range of countries and continents represented by conference delegates and authors of papers in the special issue illustrates the global relevance of aquatic plant research in the early twenty first century but also the many challenges that this burgeoning scientific discipline must address.

- by Kevin Wood
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- Botany, Environmental Science, Ecosystems Ecology, Plant Ecology
- by Ágnes Irma György
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- Earth Sciences, Hydrobiology, Eutrophication, Biological Sciences

Basándose en que los procesos de biomonitorización aportan información muy valiosa sobre los impactos en organismos y consecuentemente en el estado ecológico de los ecosistemas, la Directiva Marco del Agua (WFD; Unión Europea, 2000) incorpora el uso de indicadores biológicos y métricas para la evaluación del estado ecológico de las masas de agua.

- by Manuel Toro
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- Macrophytes

Chydorus sphaericus, a cladoceran characterized by a wide range of distribution, is often numerous in various water habitats. Its body size is a consequence of environmental characteristics and physiology. The aim of the study focused on the distribution of body size and densities of C. sphaericus in relation to environmental conditions represented by: (i) habitat types (elodeids, helophytes, and the open water); (ii) specific pond types (forest and field); (iii) pond size (surface area); (iv) the presence/lack of fish; and (v) physicochemical factors. Similar to large daphnids, in the case of the examined small water bodies, fish presence was responsible for a reduction of the body size of C. sphaericus in the zone of open water. More abundant crustacean communities and the presence of larger specimens were found among macrophytes, which indicated that aquatic vegetation offered optimal growth conditions as well as an effective refuge against fish predation. These facts reflect the necessity for maintaining a varied mosaic of habitats even in small water bodies such as the examined ponds. We found that not only the abundance of C. sphaericus but also its body size can be used as an bioindicator of environmental conditions as it preferred small and eutrophic ponds, particularly those with complex macrophyte cover (such as elodeids). Furthermore, the abundance pattern of zooplankton dominant species was affected by elodeids and fish presence as well as by the area of the ponds.

- by Natalia Kuczyńska-kippen and +1
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- Ecology, Hydrobiology, Macrophytes, Zooplankton
- by V. Plášek
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- Evolutionary Biology, Plant Biology, Bryology, Aquatic Plants

Shallow polymictic lakes are very abundant in many regions of the world, they are more numerous than deep lakes and are of great importance especially in densely populated areas even when small. Their ecology differs from stratified lakes in many ways. During the eutrophication process, lakes may change from a clear water, macrophyte dominated state to an algal dominated state, a process known as the concept of 'alternative stable equilibria'. The usefulness of this concept as a descriptor for the eutrophication process and as the basis for rehabilitation of lakes is tested on long-term data from two contrasting case study sites using a novel multivariate bubble-plot technique. In one case the concept proved to be useful and successful while it could not be applied to a large shallow turbid lake. The equilibrium concept is then generalised using further examples. Shallow lakes which are either macrophyte dominated or light limited because of high inorganic background turbidity have ratios of total phosphorus (TP) to algal Chlorophyll-a at or below 3:1. Deep oligotrophic or algal dominated lakes in contrast exhibit ratios between 3:1 and 1:1. Alternative stable equilibria of macrophyte or algal domination can occur within the same water-body at various locations, at different times of the year or during trophic development.

- by Erik Jeppesen
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- Management, Earth Sciences, Environmental Management, Eutrophication

1. Zooplankton may react differently to chemical signals produced by macrophytes in shallow systems. They may be attracted by macrophytes, as the plants may be used as a refuge against predators, or the plants may have a repellent effect (e.g. when the plants are a habitat for numerous invertebrate predators or fish). In fishless Patagonian ponds, the structural complexity provided by macrophytes modulates the rate of predation on zooplankton by the invertebrate predator Mesostoma ehrenbergii (Turbellaria). 2. We performed a field study to analyse the coexistence of M. ehrenbergii and three of its prey (two copepods, the calanoid Boeckella gracilis and the cyclopoid Acanthocyclops robustus, and the cladoceran Ceriodaphnia dubia) in four ponds. In two of the ponds, we carried out day and night sampling to evaluate the influence of macrophytes on the distribution of these zooplankters. 3. In laboratory experiments, we analysed the response of the zooplankters to the chemical signals produced by macrophytes (the emergent Juncus pallescens and the submerged Myriophyllum quitense), the predator M. ehrenbergii and the 'alarm signal' provided by a homogenate of conspecifics. 4. Our field studies demonstrated the coexistence of M. ehrenbergii and the selected prey in different seasons and that A. robustus and C. dubia choose the vegetated area (a mixed bed of J. pallescens and M. quitense) over the non-vegetated area. The habitat choice experiments indicated that the presence of M. ehrenbergii may directly affect the habitat selection of B. gracilis, because this zooplankter swam away from the predator. In addition, Mesostoma may indirectly affect the habitat selection of the cyclopoid copepod A. robustus and the cladoceran C. dubia as both zooplankters exhibited a negative response to the alarm signal produced by crushed conspecifics. 5. The presence of the submerged M. quitense did not affect the horizontal movements of any of the zooplankters studied. In contrast, the emergent macrophyte J. pallescens elicited a positive response of B. gracilis, suggesting that this aquatic plant may act as a predation refuge. 6. Our results suggest that predator avoidance behaviour can occur in fishless environments in response to a tactile invertebrate predator like Mesostoma. In addition, the refuge effect of emergent macrophytes, enhancing the survival of pelagic zooplankters, may act as a key factor in stabilizing predator-prey interactions in fishless Patagonian ponds, as has been widely recorded in northern temperate lakes with fish.

- by Esteban Balseiro
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- Freshwater Biology, Biological Sciences, Environmental Sciences, Macrophytes

We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes δ 13 C and δ 15 N, six trophic chains were identified during a previous study. Four are based on only one source: seston, organic matter from the bottom sediment, periphyton and macrophytes. Two are based on mixed sources (seston and periphyton in one case, periphyton and macrophytes in the other). During sampling, we found only one taxon that had surface sediment organic matter as food source and very few taxa whose trophic source was constituted by macrophytes. The periphyton was the most important source during all seasons; it produced the longest chain, with three trophic positions. Whatever the season and trophic source, all collected macroinvertebrates contained methyl mercury and the latter was biomagnified in all trophic chains that we identified. The biomagnification of methylmercury through invertebrate trophic chains accurately reflected the existence and length of these chains. Biomagnification was virtually non-existent in the sediment-based chain, low and restricted to the dry season in the macrophyte-based chain. It was significant in the seston-based chain, but limited by the existence of only two trophic levels and restricted to the wet season. Finally, it was very effective in the periphyton-based chain, which offers the highest rate of contamination of the source but, above all, the largest number of trophic levels.

- by Eduardo Perez Dominguez
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- Invertebrates, Bolivia, Multidisciplinary, Periphyton

Les marais de Smir (M'diq, nord-ouest du Maroc) représentent la seule zone humide de la façade méditerranéenne du Rif occidental. L'inventaire floristique a mis en évidence une importante richesse floristique estimée à 88 espèces hygrophiles. Les principales formations végétales ont été identifiées et leur écologie a été approchée. L'estimation de la biomasse maximale aérienne chez 13 formations hygrophiles a mis en évidence des groupes à biomasses faible (84 g/m 2 ), moyenne (1076 g/m 2 ) et élevée (2233 g/m 2 ). Le développement de ces différentes formations est discuté en fonction des conditions stationnelles et des impacts des principales perturbations subies par le site. Le niveau remarquable de la diversité floristique observée ainsi que la diversité des habitats dans ce site nécessitent une mise en place de mesures urgentes de protection.

- by Ater Mohammed
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- Wetlands, Macrophytes, Population Density, Wetland Flora

We evaluated the abundance patterns of Gammarus fasciatus and Echinogammarus ischnus in dreissenid and macrophyte areas in Hatchery Bay, Lake Erie before (1997) and after round goby (2001, 2002) invaded the area. Total amphipod abundance was higher before round goby invasion in both habitats. In mussel beds, E. ischnus abundance was similar or significantly higher than G. fasciatus. In macrophytes, G. fasciatus was significantly more abundant than E. ischnus. In laboratory experiments, we compared amphipod survivorship and growth when fed mussel feces and pseudofeces (F+P) or macrophytes with epiphytes (M+E). Gammarus fasciatus survivorship and growth were higher when fed F+P than M+E. Echinogammarus ischnus showed similar survivorship under both diets, but significantly higher growth when fed M+E than F+P. Therefore inter-habitat differences in food resources cannot explain the abundance patterns observed in the lake. We also estimated the relative vulnerability of G. fasciatus and E. ischnus to yellow perch (Perca flavescens) and round goby (Neogobius melanostomus) predation in laboratory feeding trials using mussel colonies or macrophyte beds as substrate. Both fish strongly preferred E. ischnus in macrophytes, but consumed relatively more G. fasciatus than E. ischnus in dreissenid habitats. Our results suggest that dreissenid establishment may have facilitated the invasion of E. ischnus. However, habitat-specific differences in vulnerability to fish predation may mediate the coexistence of G. fasciatus and E. ischnus by minimizing expansion of E. ischnus to macrophyte areas. Our results also suggest that round goby invasion can alter amphipod abundance patterns in Lake Erie.

- by María José González
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- Environmental Engineering, Great Lakes, Species Coexistence, Macrophytes

Distribution of Cornops aquaticum, C. brevipenne, C. frenatum and C. paraguayense is given for Latin America and the Caribbean Islands, along with native host plants and other plants that are repeatedly attacked. A database has been produced following new examinations of museum specimens. Occurrences are depicted in maps arranged to collecting localities and biogeographic provinces.

- by Marcos Lhano
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- Zoology, Biological Control, Latin America, Macrophytes

Our study aimed to test the ability of aquatic plants to use bicarbonate when acclimated to three different bicarbonate concentrations. To this end, we performed experiments with the three species Ceratophyllum demersum, Egeria densa, Lagarosiphon major to determine photosynthetic rates under varying bicarbonate concentrations. We measured bicarbonate use efficiency, photosynthetic performance and respiration. For all species, our results revealed that photosynthetic rates were highest in replicates grown at low alkalinity. Thus, E. densa had approx. five times higher rates at low (264 ± 15 mol O 2 g −1 DW h −1 ) than at high alkalinity (50 ± 27 mol O 2 g −1 DW h −1 ), C. demersum had three times higher rates (336 ± 95 and 120 ± 31 mol O 2 g −1 DW h −1 ), and L. major doubled its rates at low alkalinity (634 ± 114 and 322 ± 119 mol O 2 g −1 DW h −1 ). Similar results were obtained for bicarbonate use efficiency by E. densa (136 ± 44 and 43 ± 10 mol O 2 mequiv. L −1 g −1 DW h −1 ) and L. major (244 ± 29 and 82 ± 24 mol O 2 mequiv. L −1 g −1 DW h −1 ). As to C. demersum, efficiency was high but unaffected by alkalinity, indicating high adaptation ability to varied alkalinities. A pH drift experiment supported these results. Overall, our results suggest that the three globally widespread worldwide species of our study adapt to low inorganic carbon availability by increasing their efficiency of bicarbonate use.

- by Annette Baattrup-pedersen
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- Photosynthesis, Plant Biology, Aquatic botany, Macrophytes
- by Martin Dokulil
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- Management, Earth Sciences, Climate Change, Environmental Management