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The widespread existence and persistence of antibiotics in the aquatic environment, and their extensive ecological risks, have attracted considerable attention. The objective of this study was to evaluate the occurrence and distribution of 25 antibiotics in environmental and biological samples from Poyang Lake Basin in China. SPE–HPLC–MS/MS was used to quantify the concentrations in different matrices. The total concentrations ranged from 144 to 933 ng/L in the water and 346 to 1154 ng/g in the sediment. In the spatial distribution analysis of this basin, the concentrations in the Ganjiang River were generally higher than those in Poyang Lake. The seasonal distribution in the wet and dry seasons showed comparatively higher concentrations during the dry season than the wet season. Additionally, antibiotics were found in various hydrophytes and animals, and the bioconcentration factor values followed the order: emergent plants > floating plants > submerged plants and benthic organisms > ducks > fish. Moreover, correlations among different matrices showed that antibiotics in viviparid snails were significantly positively correlated with those in ducks, and negatively correlated with those in carps, indicating the transmission relationship through the food chain. The results showed the trophic transfer of antibiotics in the food web and their potential environmental impacts on Poyang Lake Basin need constant attention. [Display omitted] • Antibiotics in Ganjiang River were higher than that in Poyang Lake. • K ow and pK a values of antibiotics were critical to their concentrations. • Viviparid snails were significantly correlated with ducks and carps. • Macrolides presented the main ecology risk factors to Poyang Lake Basin. [ABSTRACT FROM AUTHOR]

The construction of four large reservoirs for hydroelectric power generation in the main channel of the Paraná River and many others in the tributaries has eliminated important wetlands, except over an area of ∼2000 km2 between the reservoirs of the UHE Engenheiro Sérgio Motta (Porto Primavera) and the Itaipu. The up-river reservoirs created large changes in the river's hydrology and in its loads of suspended, bed and dissolved material. A detailed assessment of the impact of these changes requires a description and classification of the floodplain's different subunits, called macrohabitats, according to hydrological, hydromorphological, and vegetational parameters. The classification system presented herein is hierarchical and is embedded in the classifications of Brazilian wetlands. The system differentiates the Paraná River floodplain into 6 functional units, 13 subclasses, and 23 macrohabitats, which are presented in this paper. Changes in hydrology have reduced the flood amplitude, frequency and permanence, and thus confined the macrohabitats to an area currently subjected to a regular flood pulse of ∼3 m rather than the previous ∼6 m. The gradual terrestrialization of macrohabitats at the upper end of the flood gradient is expected, accompanied by a loss of macrohabitats at its lower end because of long-term flooding. The retention of sediments and dissolved nutrients in the reservoirs will lead to the oligotrophication of aquatic macrohabitats, the degradation of near-channel hydromorphic structures and their vegetation, and a general reduction of overall primary production in the floodplain, which may extend also to higher trophic levels. [ABSTRACT FROM AUTHOR]

[Display omitted] • Full life-cycle utilization of hydrophytes in CWs is discussed. • Nitrogen removal and GHGs reduction in CWs are simultaneously evaluated. • Optimization of plant species composition is a key to improve CW performance. • Construction of an ideal CW system from the viewpoint of hydrophytes is proposed. With the prominence of global climate change and proposal of carbon reduction concept, how to maximize the comprehensive effect of nitrogen removal and greenhouse gases (GHGs) reduction in constructed wetlands (CWs) has become crucial. As indispensable biological component of CWs, hydrophytes have received extensive attention owing to their application potential. This review comprehensively evaluates the functions of hydrophytes in nitrogen removal and GHGs reduction in CWs in terms of plants themselves, plant-mediated microbes and plant residues (hydrophyte carbon sources and hydrophyte-derived biochars). On this basis, the strategies for constructing an ideal CW system are put forward from the perspective of full life-cycle utilization of hydrophytes. Finally, considering the variability of plant species composition in CWs, outlooks for future research are specifically proposed. This review provides guidance and novel perspectives for the full life-cycle utilization of hydrophytes in CWs, as well as for the construction of an ideal CW system. [ABSTRACT FROM AUTHOR]

Direct or incidental ingestion of fruits or seeds by freshwater turtles can facilitate seed dispersal within and between bodies of water. Here, we evaluate Chrysemys picta (Eastern painted turtles) as a dispersal mode for hydrophytes and aimed to determine: 1) factors that drive diversity and abundance of egested seeds, 2) if certain regionally-common seed taxa more frequently occur in feces, and 3) assess the viability of seeds that passed through the turtle digestive system. Close to half of the turtles captured were found to egest seeds with a high proportion of these seeds (85–94%) apparently unaffected by the digestive process. In all, 5859 seeds (ranging from 1 to 1081 per feces) were recovered representing four plant taxa. Most seeds recovered from either pond, in terms of overall quantity, density, and frequency, were those of the locally-common Nymphaea odorata , followed by Nuphar variegata , suggesting these items may be actively targeted as food items. Analyses indicate neither turtle sex nor health had an effect on overall seed number or seed richness of feces. While germination levels varied by turtle and locality, defecated N. odorata seeds were capable of germinating at high capacities. When compared to control, however, trials suggest C. picta ingestion has an inhibitory effect. Our evidence supports a complementary bi-modal dispersal system implicating the mobile C. picta with hydrochory to enhance the transport of aquatic plants like N. odorata . The seed treatment and high mobility afforded by C. picta makes it an effective vector to overcome interpond limitations of hydrochory and ichthyochory, and potential seed mistreatment by some waterbirds. [ABSTRACT FROM AUTHOR]

We hypothesize that the physical features of river habitats and anthropogenic hydromorphological alterations influence macrophyte communities and lead to habitat fragmentation. Sampling included 1081 contiguous survey units positioned in the main channel and side arms along 588 km of the Danube River, along its middle course. To identify habitat fragments, Multivariate Regression Tree analysis (MRT) was applied on macrophyte and environmental data. Indicator species analyses were combined with MRT. To identify habitat fragments on a scale larger than final MRT groups, we set thresholds for an MRT complexity parameter. We identified 20 fine, 7 medium, and 3 large scale habitat fragments. Damming was the main fragmentation agent. Macrophyte communities show continuous variation at all scales of habitat fragmentation. High species diversity indicates major anthropogenic alteration of the river's hydrology and decline of the natural riparian zone. Future studies of the macrophyte communities, and their habitat fragmentation must include more factors (e.g. nutrient status, physicochemical quality of the water, etc.), as well as assessment of the importance of tributaries. [ABSTRACT FROM AUTHOR]

Highlights • Water bodies of Drava River have high species richness of macrophytes and dytiscids. • Different beetle species were affected by different hydrophyte species. • Correct macrophyte management can positively affect Dytiscidae species richness. Abstract Here, we examine the relationships between the macrophyte community structure and the presence and abundance of the water beetle family Dytiscidae in 35 water bodies along the Drava River (Slovenia). In addition, selected water quality parameters were examined. The surveyed water bodies differed in altitude, type, size and distance from the Drava River. With the exception of a weak size effect on the water beetles, these parameters did not significantly affect the community structure. For hydrophyte plants, the community structure was significantly related to water quality parameters, which explained 38% (p ≤ 0.05) of the variability of species presence and abundance. For the water beetles, the oxygen concentration, and the sodium, potassium and chlorine ion concentrations were significant, together explaining 24% (p ≤ 0.05) of the species variability. Redundancy analysis revealed the importance of the presence and abundance of the low-growth plant species Potamogeton trychoides for the occurrence of Cybister lateralimarginalis, Dytiscus marginalis, Graphoderus cinereus, Graphoderus austriacus, Hydaticus seminiger and Acilius canaliculatus , while other water beetle species were more related to floating leaf plant species. Altogether, the presence and abundance of hydrophytes explained 35% of the variability of the Dytiscidae water beetle species presence and abundance. This study demonstrates the importance of selected natant plant species and submerged plant species, with low-growth forms for the occurrence of large and medium sized Dytiscidae water beetle species. Therefore, correct management of the macrophyte vegetation can positively affect the richness of these Dytiscidae species. [ABSTRACT FROM AUTHOR]

An important aspect of constructed wetlands design for landfill leachate treatment is the assessment of landfill leachate phytotoxicity. Intravital methods of plants response observation are required both for lab scale toxicity testing and field examination of plants state. The study examined the toxic influence of two types of landfill leachate from landfill in Zakurzewo (L1) and landfill in Wola Pawłowska (L2) on five plant species: reed Phragmites australis (Cav.) Trin. ex Steud, manna grass Glyceria maxima (Hartm.) Holmb., bulrush Schoenoplectus lacustris (L.) Palla, sweet flag Acorus calamus L., and miscanthus Miscanthus floridulus (Labill) Warb. Transpiration measurement was used as indicator of plants response. The lowest effective concentration causing the toxic effect (LOEC) for each leachate type and plant species was estimated. Plants with the highest resistance to toxic factors found in landfill leachate were: sweet flag, bulrush, and reed. The LOEC values for these plants were, respectively, 17%, 16%, 9% in case of leachate L1 and 21%, 18%, 14% in case of L2. Leachate L1 was more toxic than L2 due to a higher pH value under similar ammonia nitrogen content, i.e. pH 8.74 vs. pH 8.00. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) are frequently detected in wastewaters, especially in industrial discharges. Phytoremediation is one of the promising low cost, environmental friendly and efficient technique to remove HMs from industrial wastewater. The current research was carried out to investigate the ability of constructed wetland (CW) for the removal of HMs including copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni) and chromium (Cr) from local wastewater of industries by using two local common hydrophytes species Pistia stratiotes and Lemna Gibba. After 45 days cultivation, the concentration of HMs reduced to 0.25–0.90 mg/L and 0.78–1.4 mg/L from 5 mg/L for Lemna gibba and Pistia stratiotes , respectively. The HMs removal efficiency ranged from 82% to 95% for Lemna gibba and 72%–84.4% for Pistia stratiotes. The accumulation of HMs in roots are always higher than that in aerial part including stems and leaves for both plants. The accumulation of HMs in roots of Lemna gibba ranged from 4.3 to 4.7 mg/kg and, 1.85–3.9 mg/kg in aerial part. The corresponding values were 3.9–4.7 mg/kg and, 1.75–3.3 mg/kg for Pistia stratiotes. Results of health risk models including the average daily intake (ADI), hazard quotient (HQ) and cancer risk (CR) models indicated lower health risk of water after treatment than before treatment water. Result indicated the selected hydrophytes could be applied for HMs treatment from contaminated water. [ABSTRACT FROM AUTHOR]

Highlights: [•] Isolation and identification of root exudates from five hydrophytes in CWs. [•] Coliphages T4 and f2 were well removed by root extracts of P. hydropiper. [•] The EC50 of P. hydropiper root on coliphages T4 and f2 was 0.6 and 7.6mgL−1, respectively. [•] The IR of saturated n-butanol phase on T4 and f2 was found to be the strongest. [ABSTRACT FROM AUTHOR]

Abstract: Understanding of species–habitat relationship is fundamental to effective conservation planning and management. We studied the association of Little Grebe abundance with habitat parameters at Kallar Kahar Lake, District Chakwal, Punjab, Pakistan, from September 2010 to July 2011. Bird population density data, vegetation and physico-chemical parameters were collected along three strips from different areas of the lake based on habitat variability. The association of Little Grebe abundance with physico-chemical parameters of water was determined using simple linear regression. The physico-chemical parameters differed significantly (P <0.05) among the three strips. Water temperature and turbidity were negatively related while pH and depth were positively related with grebe population. We concluded that the species more frequently occurred in shallow water habitats with preponderance of reed vegetation, slightly high alkalinity, low water temperature and low turbidity. The reed vegetation such as Phragmites and Typha provided shelter and nesting sites while open water had abundant planktons and crustaceans, algae such as Spirogyra spp. and submerged vegetation such as Chara spp. provided foraging sites. Threats to the species included eutrophication, fluctuation in the water level and littering by visitors which need to be addressed through appropriate management interventions. [Copyright &y& Elsevier]

Abstract: Petiole anatomy of the north-eastern Brazilian species Echinodorus glandulosus, E. palaefolius, E. pubescens, E. subalatus, E. lanceolatus and E. paniculatus were examined. All species had petioles with an epidermis composed of tabular cells with thin walls. The chlorenchyma just below the epidermis alternates with collateral vascular bundles. The interior of the petiole is filled by aerenchyma with ample open spaces or lacunas. The lacunas are bridged at intervals by plates, or by diaphragm-like linkages. There are lactiferous ducts and groups of fibres throughout the entire length of the petiole, but more frequently in the chlorenchyma. Important taxonomic characteristics for the genus Echinodorus include the shape and outline of the petiole in transversal section, the presence of winged extensions, and the number of vascular bundle arcs. Exceptions occur in E. lanceolatus and E. paniculatus, whose petioles have similar anatomic patterns. A comparative chart of the petiole anatomic characteristics analyzed is presented. [Copyright &y& Elsevier]

Abstract: Of the 20 plant species of hydrophytes screened for Arbuscular Mycorrhizal (AM) fungal root colonization, 10 aquatic plants (out of 14 species) and five marshy plants (out of six species) were found to be mycorrhizal, while the remaining species were non mycorrhizal. Vesicular colonization occurred in 12 plant species while arbuscular colonization was restricted to only three plant species. A rooted submerged pteridophyte viz., Isoetes coromandelina L. was found to be mycorrhizal exhibiting vesicular colonization. In all, two genera viz., Glomus and Scutellospora, the former being dominant, were recorded. The most common AM fungal species Glomus claroideum was recovered from 14 plant species. [Copyright &y& Elsevier]

Concentrations of heavy metals (Cd, Pb, Cr, Ni, Zn and Cu) were measured in bottom sediments, water and Typha angustifolia and Potamogeton pectinatus in Sultan Marsh. Sultan Marsh is one of the largest and most important wetlands in Turkey, Middle East and Europe, embodying saline and fresh water ecosystems and providing a shelter for 426 bird species. The organs of T. angustifolia have a larger quantity of the measured elements than the P. pectinatus. Considerably higher contents of Cd were found rather than in helophytes (P. pectinatus) in submerged plant (=emergent, T. angustifolia) species. The percentage of Cd in plant tissues points to a certain degree of water pollution in Sultan Mash. Analyses of water, bottom sediments and plant samples indicated that the Marsh were polluted with Pb, Cd, and partly with Cu and Zn. All sampling sites in the study area basin are generally more or less polluted when compared with the control values. Strong positive correlation was found between concentrations of Pb in water and in plants. Ni and Pb were accumulated by plants at a higher rate from bottom sediments than from water. Leaves of T. angustifolia accumulated less heavy metal than the corresponding roots. There was a significant relationship between Cd concentration in samples of plants and water pH value. It has been found that the tissues of T. angustifolia accumulate more heavy metals than the tissues of P. pectinatus. Therefore, all plants can be used as a biological indicator while determining environmental pressures; however, T. angustifolia is proved more appropriate for such studies. [Copyright &y& Elsevier]

The extent to which invasive aquatic plants move via accidental inclusion in aquatic plant orders or sale of prohibited species is unknown. Forty orders were placed to 34 aquatic plant vendors across the US between May and September 2001 to determine the prevalence of movement into Minnesota via horticultural trade. Federal noxious weeds or Minnesota prohibited exotic species were acquired 92% of the time they were ordered and included Alternanthera sessilis, Butomus umbellata, Hydrocharis morsus-ranae, Potamogeton crispus, and Lythrum salicaria. Ninety three percent of orders received from aquatic plant vendors contained a plant or animal species not specifically requested; 10% of these purchases contained federal noxious weeds or Minnesota exotic species. Lemna minor was the most common incidental receipt found per taxa and per purchase, although Hydrilla verticillata, Lythrum salicaria, Salvinia molesta, and Potamogeton crispus (all prohibited taxa) were also found. Misidentified plants were found in 18% of the orders; unordered seeds in 43%. The sale and transport of prohibited aquatic plants likely presents the greatest risk associated with the aquatic plant trade. Other important factors include misidentification leading to the unintentional sale of invasive plants and the incidental inclusion of species during translocation. [Copyright &y& Elsevier]

Investigations were carried out to evaluate if hydrophytes (viz. Ceratophyllum, Wolffia, and Hydrilla) can be used as markers to assess the level of heavy metal pollution in aquatic bodies. The potential of these hydrophytes for lipid peroxidation and accumulation of proline in response to cadmium (Cd2+) pollution was studied. Hydrophytes were raised in artificial pond water (APW) supplemented with various levels of Cd2+. Interestingly, unlike mesophytes none of the hydrophytes showed ability to accumulate proline. Infact, in response to Cd2+ pollution hydrophytes exhibited a decline in proline levels in comparison to controls but mesophytes (viz. Brassica juncea, Vigna radiata and Triticum aestivum) showed progressive increase in the level of proline with increase in the extent of Cd2+ pollution. Mesophytes showed six to nine-fold increase in the level of proline in response to 1 mM Cd2+. The potential of the above hydrophytes for lipid peroxidation was also low under Cd2+ stress. In contrast, as expected a significant enhancement in the lipid peroxidation was observed in all three mesophytes in response to their exposure to Cd2+. About two-fold increase in production of malondialdehyde (a cytotoxic product of lipid peroxidation) was recorded in mesophytes exposed to 1 mM Cd2+. However, a decline in chlorophyll (Chl a and Chl b) levels was recorded in response to Cd2+pollution both in hydrophytes as well as mesophytes. In summary, hydrophytes neither have potential to accumulate proline nor have ability to accelerate lipid peroxidation under heavy metal stress. This suggests that the adaptive mechanism(s) existing in hydrophytes to tackle heavy metal stress is distinct from that in mesophytes. [Copyright &y& Elsevier]

• Few broad-scale patterns are well-studied for aquatic macrophytes. • Local environmental predictors were important for freshwater plants at broad-scales. • Several knowledge gaps on macroecology of freshwater plants were identified. • Lack of lotic studies and databases of species traits and phylogeny were found. • Additional macroecological investigations on freshwater plants are clearly needed. Broad-scale studies of species distributions and diversity have contributed to the emergence of general macroecological rules. These rules are typically founded on research using well-known terrestrial taxa as models and it is thus uncertain whether aquatic macrophytes follow these macroecological rules. Our purpose is to draw together available information from broad-scale research on aquatic macrophytes growing in lakes, ponds, wetlands, rivers and streams. We summarize how different macroecological rules fit the patterns shown by freshwater plants at various spatial scales. Finally, we outline future actions which should be taken to advance macroecological research on freshwater plants. Our review suggested that some macroecological patterns are relatively well-evidenced for aquatic macrophytes, whereas little information exists for others. We found, for example, that the species richness-latitude relationship follows a unimodal pattern, and species turnover prevails over species nestedness, whereas higher nestedness-related richness differences are found in low beta diversity regions. Contrary to terrestrial plants, climate or history seem not to be dominant determinants explaining these broad-scale patterns; instead local explanatory variables (e.g., water quality, such as alkalinity and nutrients, and hydromorphology) are often important for freshwater plants. We identified several knowledge gaps related, for example, to a smaller number of studies in lotic habitats, compared with lentic habitats, lack of spatially-adequate aquatic plant studies, deficiency of comprehensive species traits databases for aquatic macrophytes, and absence of a true phylogeny comprising most freshwater plant lineages. We hope this review will encourage the undertaking of additional macroecological investigations on freshwater plants across broad spatial and temporal scales. [ABSTRACT FROM AUTHOR]

• Playas support plant species not found in surrounding agricultural watersheds. • Plant abundance, richness, and diversity were unaffected by rainfall and land use change. • Projected future precipitation benefited native plant species richness. • Greatest native species richness occurred under control nitrogen loading (0 mg-N/L). Playa wetlands in the Great Plains, USA support a wide variety of plant species not found elsewhere in this agriculturally-dominated region due to the ephemeral presence of standing water and hydric soils within playas. If longer dry periods occur due to climate change or if changes in surrounding land use alter sediment accumulation rates and water storage capacity in playas, plant communities could experience decreased diversity, with lasting effects on ecosystem services provided by playas in the Great Plains and at a continental-level in North America. We quantified potential changes in playa wetland plant community composition associated with predicted changes in precipitation and land use in the Great Plains through the end of the 21st century. We conducted two six-month greenhouse experiments mimicking field conditions using intact mesocosms collected from playas in Nebraska and Texas. In the precipitation experiment, treatments derived from historical precipitation observations and three future moderate emissions (CMIP5 RCP4.5) downscaled climate projections were applied to mesocosms. For the land use experiment, treatments were simulated by nitrogen (N) applications to soil ranging from 0 to 100 mg-N L-1 with each precipitation event under historical rainfall patterns, representing increasing and decreasing area in agricultural use in playa watersheds. Plant communities tended to shift toward more native species under projected future climate conditions, but as N runoff increased, native species richness decreased. Agricultural land-use surrounding playas may have a greater effect on wetland plant communities than future alterations to hydrology based on climate change in the Great Plains; thus, efforts to reduce nutrient runoff into playas would likely mitigate loss in ecosystem function in the coming decades. [ABSTRACT FROM AUTHOR]