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1

Chambers, Patricia A., Robert E. DeWreede, Elizabeth A. Irlandi, and Herbert Vandermeulen. "Management issues in aquatic macrophyte ecology: a Canadian perspective." Canadian Journal of Botany 77, no. 4 (September 28, 1999): 471–87. http://dx.doi.org/10.1139/b99-092.

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During the past few decades, attempts to manage excessive abundance of freshwater macrophytes, decreasing abundance of marine eelgrass (Zostera marina L.), and abundance and diversity of seaweeds have yielded modest successes, some short-term recoveries, and other complete failures. As many broad principles apply to the management of all aquatic plants, the aim of this paper was to synthesize the issues and provide direction for the management of freshwater rooted macrophytes, eelgrass, and marine macrophytic algae and place them in a Canadian context. Specifically, we examine biomass and landscape objectives for macrophyte management, assess the role of environmental manipulation for the management of macrophyte assemblages, and provide direction for managing macrophyte assemblages within the context of ecosystem sustainability. Finally, we advocate that, given the unexpected outcomes that may arise from uncontrolled events (e.g., weather, inherent variability in life history characteristics), management interventions should be designed in such a way that it is possible to make valid conclusions about the outcome of any given management action (i.e., design the management action to be a scientific experiment).Key words: macrophyte, algae, eelgrass, herbivores, nutrients, landscape ecology.
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2

Cahoon, Lawrence B., Michael A. Boller, Marc O. de Labry, Chandler A. Kosh, Matthew D. McDowell, Jessica E. Nixon, Robin L. Taylor, and Rebecca J. Wilson. "Phosphorus Partitioning in a Storm Water Pond." Journal of North Carolina Academy of Science 131, no. 2 (December 1, 2015): 25–28. http://dx.doi.org/10.7572/2167-5872-131.2.25.

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Abstract Storm water ponds are commonly employed to trap sediments, nutrients and other pollutants in non-point runoff. Aquatic macrophytes are thought to offer enhanced nutrient control via nutrient uptake and other processes. This study sampled and compared the phosphorus contents of water, sediment, and a dominant macrophyte, Stuckenia pectinata (Sago Pond Weed), in a storm water detention pond in the fall of 2013 and 2014. Phosphorus concentrations [ug P (g material)−1] were much higher in macrophyte tissues than in sediment and water, but the areal amounts of phosphorus (mg P m−2) bound in these three forms were ranked differently: sediment>>water>macrophyte, with macrophyte-bound P accounting for only <1–2% of total P in this pond. Macrophyte management may, therefore, have only marginal effectiveness in nutrient control by storm water detention ponds, although macrophytes support a variety of other ecosystem services.
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3

Lalonde, Sophie, and John A. Downing. "Phytofaun of Eleven Macrophyte Beds of Differing Trophic Status, Depth, and Composition." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 5 (May 1, 1992): 992–1000. http://dx.doi.org/10.1139/f92-111.

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Macrophyte beds in 11 lakes of differing trophic conditions were sampled intensively to examine the influence of macrophyte abundance and composition, epiphyton biomass, phytoplankton concentration, and water depth on the abundance of phytophilous invertebrates. Numerical abundance and biomass of phytofaunal taxa were only weakly correlated. Phytofauna biomass ranged from 17 to 270 mg dry mass∙g macrophyte dry mass−1(1–29 g dry mass∙m−2) among the macrophyte beds. Multiple regression analysis showed that total phytofaunal biomass was positively correlated with the biomass of the three primary producers in the littoral zone: macrophytes, epiphyton, and phytoplankton. Phytofauna biomasses in deeper macrophyte beds or near the water surface were lower than those found in shallower water or near the sediment surface. Correlations of phytofauna biomass with macrophytes, epiphyton, and depth varied somewhat among phytofaunal taxa. The phytofauna biomass was often dominated by chironomid larvae, but gastropods, water mites, and oligochaetes were also important components of the phytofauna biomass. Small crustaceans such as cladocerans and copepods frequently were numerically dominant but usually composed only a small fraction of the biomass. Preference of various invertebrate taxonomic groups for particular species of aquatic macrophyte was slight.
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4

Riddin, T., and J. B. Adams. "Predicting macrophyte states in a small temporarily open/closed estuary." Marine and Freshwater Research 63, no. 7 (2012): 616. http://dx.doi.org/10.1071/mf11224.

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Temporarily open/closed estuaries (TOCEs) shift between abiotic states associated with mouth status. The aim of this study was to assess whether macrophyte states could be identified based on the dominant cover abundance of different species representative of specific habitats. A 5-year dataset of monthly macrophyte cover was assessed for the East Kleinemonde Estuary in South Africa. Three macrophyte states were identified: namely open and tidal (predominantly intertidal salt marsh); closed and low water level (predominantly salt marsh); and closed and high water level (with submerged macrophytes). The threshold water level for the change from salt marsh to submerged macrophytes was 1.6 m above mean sea level (amsl). A fourth state where macroalgae were dominant was identified for high salinity conditions (above 30 PSU). It was then possible to examine simulated water level data for different inflow scenarios to determine how often these macrophyte states occurred. Available macrophyte habitat was also calculated for different water levels using a spatial model written in Modelbuilder (ArcGIS 9.3.1). Both methods used to predict available macrophyte habitats are rapid, requiring only information on the elevation range of the main habitats, as well as present distribution and bathymetric maps. These predictive techniques are useful in the determination of the ecological water requirements of small estuaries.
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5

Silva, Suelen Cristina Alves da, Armando Carlos Cervi, Cleusa Bona, and André Andrian Padial. "Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication." Acta Limnologica Brasiliensia 26, no. 2 (June 2014): 129–42. http://dx.doi.org/10.1590/s2179-975x2014000200004.

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AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i) through two‑way ANOVAs considering the stand extent (m) and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand); and ii) through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.
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6

Hu, Wen, Weiwei Wei, Chun Ye, Chunhua Li, Ye Zheng, Xiaogang Shi, Manqi Chang, and Hongsen Chen. "Determining the Optimal Biomass of Macrophytes during the Ecological Restoration Process of Eutrophic Shallow Lakes." Water 13, no. 21 (November 8, 2021): 3142. http://dx.doi.org/10.3390/w13213142.

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Many studies have shown that macrophytes play a significant role in controlling eutrophication; however, only a few of these are based on macrophyte biomass. Based on the growth characteristic of macrophytes, we propose an approach for the assessment of the optimal biomass of macrophytes in the decay and growth periods in Lake Datong (a shallow lake), using a lake ecological model. The results showed that the pollution load of the lake should be reduced by 50% while conforming to the Environmental Quality Standards for Surface Water (EQSSW) Class Ⅲ. In contrast, with an increase in the pollution load of 5%, the results indicate that the lake may deteriorate to a turbid state over the next few years. The macrophyte biomass should be harvested during the decay period, when 80% biomass is beneficial to the water quality of the eutrophic shallow lake. Based on macrophyte simulation from 2020–2024, the wet biomass of macrophytes should be controlled at 5.5 kg/m2. The current macrophyte biomass in Lake Datong is four-fold higher than the simulated optimal biomass. This study provides a reference for the adequate ecological restoration of the lake and its subsequent maintenance, as well as scientific support for improving the comprehensive evaluation standard of healthy lakes and the theoretical basis of lake ecological restoration.
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7

Vis, Chantal, Christiane Hudon, and Richard Carignan. "Influence of the vertical structure of macrophyte stands on epiphyte community metabolism." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 5 (May 1, 2006): 1014–26. http://dx.doi.org/10.1139/f06-021.

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The physical structure of submerged aquatic plant communities differentially influences the availability of light and substratum in the water column and, thus, the functional role of epiphytes growing on macrophytes. We examined the depth distribution of photosynthesis and respiration of epiphyte communities within macrophyte stands of contrasting growth forms over a 2-year period in Lake Saint-Pierre (St. Lawrence River). To do so, we used a modelling approach, combining laboratory measurements of photosynthesis and respiration with field data of macrophyte and epiphyte biomass and vertical light attenuation. In stands dominated by canopy-forming macrophytes, shading resulted in strong vertical gradients in epiphyte metabolism, with a positive net oxygen balance in the canopy and a negative net oxygen balance in the bottom portion of the stand. In low-growing macrophyte stands, the net oxygen balance of epiphytes was either positive or negative, depending on water transparency and depth. Epiphyte communities had a daily negative net oxygen balance under light conditions below ~10% of surface light intensity. Areal production simulations demonstrated that neglecting variations in the vertical distribution of epiphytes, macrophytes, and light within macrophyte stands can result in errors in areal production estimates of >100%.
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8

Debastiani-Júnior, J. R., L. M. A. Elmoor-Loureiro, and M. G. Nogueira. "Habitat architecture influencing microcrustaceans composition: a case study on freshwater Cladocera (Crustacea Branchiopoda)." Brazilian Journal of Biology 76, no. 1 (January 22, 2016): 93–100. http://dx.doi.org/10.1590/1519-6984.13514.

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Abstract Environmental complexity is considered a key factor for diversity enhancement in aquatic ecosystems. Macrophyte stands are a major contributor for this complexity due to their differential architectures. Nevertheless, the influence of distinct aquatic habitat architectures (with different types of macrophytes or without them) on microcrustaceans’ taxa composition, usually found in macrophyte colonized water bodies, is underexplored in limnological studies. The main objective of this study was to analyze this influence by comparing the Cladocera composition among four habitat architectures: (1) fluctuant macrophytes, (2) rooted emergent macrophytes, (3) submerged macrophytes and (4) the limnetic zone of oxbow lakes associated to a large subtropical reservoir. Wide compositional variation was observed. Fluctuant macrophytes exhibited the richest Cladocera assemblage, dominated by Chydoridae. Submerged and rooted emergent macrophytes had the most similar assemblages between them. The most distinctive fauna was found in the limnetic zone, dominated by Bosminidae. Probable differences in resource availability in each sampled habitat architecture are considered as the driving factor for the Cladocera composition variation. We concluded that for a complete inventory of a given local fauna, it is imperative to take into account the aquatic habitat architecture, including macrophyte stands, in the data sampling design.
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9

Zeng, Jin, Yuanqi Bian, Peng Xing, and Qinglong L. Wu. "Macrophyte Species Drive the Variation of Bacterioplankton Community Composition in a Shallow Freshwater Lake." Applied and Environmental Microbiology 78, no. 1 (October 28, 2011): 177–84. http://dx.doi.org/10.1128/aem.05117-11.

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ABSTRACTMacrophytes play an important role in structuring aquatic ecosystems. In this study, we explored whether macrophyte species are involved in determining the bacterioplankton community composition (BCC) in shallow freshwater lakes. The BCC in field areas dominated by different macrophyte species in Taihu Lake, a large, shallow freshwater lake, was investigated over a 1-year period. Subsequently, microcosm experiments were conducted to determine if single species of different types of macrophytes in an isolated environment would alter the BCC. Denaturing gradient gel electrophoresis (DGGE), followed by cloning and sequence analysis of selected samples, was employed to analyze the BCC. The DGGE results of the field investigations indicated that the BCC changed significantly from season to season and that the presence of different macrophyte species resulted in lower BCC similarities in the summer and fall. LIBSHUFF analysis of selected clone libraries from the summer demonstrated different BCCs in the water column surrounding different macrophytes. Relative to the field observations, the microcosm studies indicated that the BCC differed more pronouncedly when associated with different species of macrophytes, which was also supported by LIBSHUFF analysis of the selected clone libraries. Overall, this study suggested that macrophyte species might be an important factor in determining the composition of bacterial communities in this shallow freshwater lake and that the species-specific influence of macrophytes on BCC is variable with the season and distance.
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10

Vermaire, Jesse C., Yves T. Prairie, and Irene Gregory-Eaves. "Diatom-inferred decline of macrophyte abundance in lakes of southern Quebec, Canada." Canadian Journal of Fisheries and Aquatic Sciences 69, no. 3 (March 2012): 511–24. http://dx.doi.org/10.1139/f2011-169.

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Submerged macrophytes play a central role in lake ecosystem functioning; however, their long-term dynamics are poorly understood. We have used the paleolimnological top–bottom approach to reconstruct changes in whole-lake macrophyte biomass between predisturbance and present-day conditions in 37 southern Quebec lakes. Estimates of whole-lake macrophyte biomass were produced using a diatom-based multivariate regression tree model (MRT) and modern analogue approach. Both approaches indicated an overall pattern of declining macrophyte abundance in the region. Based on MRT analysis, 80% of study lakes were classified as historically being in the macrophyte-dominated state, but now only 43% of the lakes are currently in this state. The lakes that shifted MRT group were found to have significantly (p = 0.03) greater building densities in their catchments compared with lakes that did not shift state. These results suggest that human impacts, primarily nutrient inputs and water level fluctuations, have played a role in reducing macrophyte abundance in southern Quebec lakes. Because submerged macrophyte beds help stabilize lake ecosystems and act as a phosphorus sink, a reduction in whole-lake macrophyte biomass could make lake ecosystems more susceptible to eutrophication.
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11

Bareuther, Mischa, Michael Klinge, and Andreas Buerkert. "Spatio-Temporal Dynamics of Algae and Macrophyte Cover in Urban Lakes: A Remote Sensing Analysis of Bellandur and Varthur Wetlands in Bengaluru, India." Remote Sensing 12, no. 22 (November 23, 2020): 3843. http://dx.doi.org/10.3390/rs12223843.

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Rapid urbanization processes and indiscriminate disposal of urban wastewaters are major causes for anthropogenic lake-sediment deposition and eutrophication. However, information about the spatial and temporal variation of macrophyte and phytoplankton distribution as indicators for water contamination is limited. To gain insights into the dynamics, we analyzed lake-cover changes of Bellandur and Varthur Lake in the S-Indian megacity of Bengaluru for the post-rainy seasons of the years 2002–2019. Supervised maximum likelihood classifications were conducted on 62 freely available, true-color satellite images in order to distinguish between macrophytes, algae, and free water surface. The image-derived results were verified by supervised classification and manual mapping of two simultaneously recorded multispectral satellite images (Sentinel-2 and WorldView-2). Seasonal interrelations between macrophytes and algae distribution were similar for both lakes. The increase in macrophyte cover during post-rainy season negatively correlated with algal abundance. Macrophyte expansion progressively suppressed algae development at both lakes, reflective of increasing eutrophication caused by on-going wastewater input. Seasonal variation in precipitation, wind direction, and temperature seemed to trigger intra-annual shifts of macrophytes and algae while similar macrophyte spread intensities during the post-monsoon season indicated independence of nutrient loads in the lake water.
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12

del Pozo, Rocío, Camino Fernández-Aláez, and Margarita Fernández-Aláez. "The relative importance of natural and anthropogenic effects on community composition of aquatic macrophytes in Mediterranean ponds." Marine and Freshwater Research 62, no. 2 (2011): 101. http://dx.doi.org/10.1071/mf10125.

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To detect when changes in response to stressors are occurring, biomonitoring programs require an understanding of shifts in biota that occur in response to anthropogenic and natural effects. Aquatic plants are expected to reflect the environmental conditions of ponds and, according to the European Water Framework Directive, macrophytes should be considered in ecological status assessments of inland surface waters. We assessed the relative importance of natural and anthropogenic impacts on submerged, emergent and floating-leaved macrophytes in 44 ponds in Duero river basin (North Iberian Plateau). Constrained canonical ordinations included 15 taxa of submerged macrophytes and 24 species of emergent and floating-leaved macrophytes. Although the proportion of variation explained by all selected variables was relatively low (37%), we found that submerged community composition reflected the influence of natural (habitat and biotic variables) and anthropogenic effects. However, emergent and floating-leaved macrophytes were not influenced by biotic variables. Variance partitioning showed that degradation category was the best predictor of both submerged macrophytes and emergent and floating-leaved macrophyte composition. However, submerged macrophytes were more affected by chemical variables, whereas emergent and floating-leaved macrophyte composition was best explained by land-use variables. The results of this study support the use of macrophyte communities as effective indicators of the ecological status of Mediterranean ponds.
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13

Briggs, SV, and MT Maher. "Limnological studies of waterfowl habitat in south-western New South Wales. II. Aquatic macrophyte productivity." Marine and Freshwater Research 36, no. 5 (1985): 707. http://dx.doi.org/10.1071/mf9850707.

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Aquatic macrophyte productivity and soil organic matter were measured in two impermanent wetlands in south-western New South Wales. Macrophyte biomasses (≤463 g dry wt m-2) were similar to or higher than those in submerged communities elsewhere. Macrophyte productivities in both wetlands were greatest in the year following reflooding. But even in that year, macrophyte productivity in Lake Merrimajeel (the only wetland for which data are available) was considerably less than soil organic reserves before reflooding. It is suggested that these soil organic reserves directly contribute to the relationship between wetland flooding and waterfowl breeding, while macrophytes contribute indirectly by providing detritus for invertebrates. It is recommended that wetlands managed for waterfowl breeding should periodically dry out and reflood.
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14

Yu, Jinlei, Manli Xia, Wei Zhen, Hu He, Ruijie Shen, Baohua Guan, and Zhengwen Liu. "A small omnivore fish (Acheilognathus macropterus) reduces both growth and biomass of submerged macrophytes: implications for shallow lake restoration." Knowledge & Management of Aquatic Ecosystems, no. 421 (2020): 34. http://dx.doi.org/10.1051/kmae/2020028.

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Transplantation of submerged macrophytes has been widely used to improve water quality in restoring shallow lakes in China. However, in some lakes, small omnivorous fish predominated the fish assemblages and fed mainly on submerged macrophytes. Despite significant research examining grazing selectivity in herbivorous fishes, macrophyte feeding preferences of small omnivorous fishes are poorly understood. We conducted a mesocosm experiment to examine the effects of a prolific small omnivorous bitterling fish Acheilognathus macropterus on the relative growth rate (RGR) and biomass of submerged macrophytes (Ceratophyllum demersum, Myriophyllum spicatum, Vallisneria denseserrulata, and Hydrilla verticillata). Our results showed that the presence of A. macropterus significantly increased nutrient concentrations (e.g. total nitrogen and total phosphorus). The RGR of C. demersum in the bitterling-present treatment was significantly lower than the controls, in the presence of other macrophyte species. Further, total biomass of the four species of macrophytes in the fish-present mesocosms was markedly lower than in the fish-absent treatment, suggesting considerable consumption of macrophytes by bitterling. Moreover, the percent biomass of V. denserrulata and H. verticillata were significantly enhanced by the presence of bitterling. Our findings suggest that A. macropterus may increase nutrient concentrations through excretion and reduce the biomass and RGR of certain submerged macrophytes which may shift macrophyte community structure via selective grazing.
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15

Lodge, David M., and James G. Lorman. "Reductions in Submersed Macrophyte Biomass and Species Richness by the Crayfish Orconectes rusticus." Canadian Journal of Fisheries and Aquatic Sciences 44, no. 3 (March 1, 1987): 591–97. http://dx.doi.org/10.1139/f87-072.

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We conducted five 4- to 12-wk in situ enclosure–exclosure experiments in four macrophyte assemblages in three northern Wisconsin lakes to test the impact of grazing by the crayfish Orconectes rusticus. Size of cages and cageless controls ranged from 1 to 3 m2. Adult crayfish reduced total macrophyte biomass in two experiments and reduced species richness in three experiments. The natural occurrence of crayfish in the study lakes ranged from 1 to 223 g live crayfish∙m−2. Crayfish abundance of 19 g∙m−2 reduced total macrophyte biomass 64%, while abundance >140 g∙m−2 eliminated all macrophytes. Decline in species richness and comparison of species abundance over time suggested that crayfish grazed selectively. Both consumptive and nonconsumptive destruction by crayfish caused macrophyte decline. Single-stemmed species were more susceptible to destruction than rosulate or branched species. Our results suggest that crayfish play an important role in structuring the macrophyte and invertebrate communities that they inhabit.
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16

Gao, Yiming, Chunyu Yin, Yu Zhao, Zhengwen Liu, Pingping Liu, Wei Zhen, Yaohui Hu, Jinlei Yu, Zhaoxia Wang, and Baohua Guan. "Effects of Diversity, Coverage and Biomass of Submerged Macrophytes on Nutrient Concentrations, Water Clarity and Phytoplankton Biomass in Two Restored Shallow Lakes." Water 12, no. 5 (May 16, 2020): 1425. http://dx.doi.org/10.3390/w12051425.

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Transplantation of submerged macrophytes to restore shallow lakes has been used as an effective measure to maintain a clear water state. Water quality is highly correlated with submerged macrophytes community, however, the relationships between water quality and the diversity, coverage and biomass of submerged macrophytes are, so far, not yet well studied. We analyzed the correlations of nutrient concentrations, water clarity and phytoplankton biomass with the metrics of submerged macrophytes community in two Chinese restored shallow subtropical lakes, Lake Wuli (Wuli-E, 5 ha) and Lake Qinhu (Qin-E, 8 ha). A similar biomass of submerged macrophytes was transplanted into each lake, while both the species richness and coverage of macrophytes in Qin-E were lower than Wuli-E. After a 1–2-year restoration, the diversity almost had no change, but the biomass density and coverage decreased in Wuli-E. As for Qin-E, the coverage of submerged macrophytes increased but biomass density and diversity decreased. The dominance of canopy-forming submerged macrophyte species Myriophyllum spicatum was observed in Qin-E and less meadow-forming biomass and species was observed than that in Wuli-E. Moreover, it was also observed that Wuli-E had a better water quality than that of Qin-E after transplantation. Path analysis results showed that macrophyte coverage and the diversity related to meadow-forming species (e.g., Vallisneria spinulosa) had strong effects on enhancing clarity and reducing nutrient concentrations. But the high biomass density accompanied by the canopy-forming species like M. spicatum was unfavorable for controlling nutrients. Our results provide important insight into the different roles that macrophyte diversity, biomass and coverage play in improving water clarity and controlling nutrient concentrations. This new knowledge will be instrumental in implementing more effective lake restoration, especially using macrophyte transplantation as a restoration tool in warm shallow lakes.
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17

Albertoni, Edélti Faria, Cleber Palma-Silva, Claudio Rossano Trindade Trindade, and Leonardo Marques Furlanetto. "Field evidence of the influence of aquatic macrophytes on water quality in a shallow eutrophic lake over a 13-year period." Acta Limnologica Brasiliensia 26, no. 2 (June 2014): 176–85. http://dx.doi.org/10.1590/s2179-975x2014000200008.

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AIM: The main objective of this work is to describe the changes in water characteristics of a shallow subtropical lake, in periods with and without growing of macrophytes, related to periods of clear-macrophyte dominance and turbid-phytoplankton dominance states. METHODS: The study was conducted in Biguás Lake, in the south coastal plain of Brazil (32° 04' 43" S and 52° 10' 03" W). Samplings were carried out monthly between October 2000 and November 2013. The limnological variables measured in the water column were dissolved oxygen (DO), water temperature, pH, electrical conductivity (EC), chlorophyll-a, total nitrogen (TN), total phosphorous (TP) and suspended material (SM). Data were grouped according to periods with macrophyte growth dominance (MD) and without macrophytes, with phytoplankton dominance (PD), and applied t- tests among TP, TN, Chlorophyll-a and SM. During macrophyte growth we estimated the coverage (%) and biomass variation of plants. RESULTS: Over the 13 years, the lake was well oxygenated, alkaline, and with a temperature variation according to subtropical seasonality. The lower values of all of the limnological variables were verified during periods of macrophyte growth, characterizing periods of clear and turbid waters. CONCLUSIONS: The influence of aquatic macrophytes in improving water quality in this shallow lake during the studied period, reducing nutrient concentrations, chlorophyll-a and suspended material in water, favoring the maintenance of a clear water state, was verified.
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18

Budka, Anna. "How many indicator species are required to assess the ecological status of a river?" Oceanological and Hydrobiological Studies 48, no. 1 (March 26, 2019): 1–12. http://dx.doi.org/10.1515/ohs-2019-0001.

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Abstract The presented research focused on macrophytes, which constitute a primary element in the assessment of the ecological status of surface waters following the guidelines of the Water Framework Directive. In Poland, such assessments are conducted using the Macrophyte Index for Rivers (MIR). The objective of this study was to characterize macrophyte species in rivers in terms of their information value in the assessment of the ecological status of rivers. The macrophyte survey was carried out at 100 river sites in the lowland area of Poland. Botanical data were used to verify the completeness of samples (the number of taxa). In the presented research, the information provided by each species was controlled. Entropy was used as the main part of information analysis. This analysis showed that the adoption of a standard approach in the studies of river macrophytes is likely to provide sample underestimation (with missing species). This may potentially lead to incorrect determination of MIR and thus result in a wrong environmental decision. On this basis, a sample completeness criterion was developed. Using this criterion, the average value of information for macrophyte species in medium-sized lowland rivers is suffcient to be considered representative.
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Chick, John H., and Carole C. Mclvor. "Patterns in the Abundance and Composition of Fishes among Beds of Different Macrophytes: Viewing a Littoral Zone as a Landscape." Canadian Journal of Fisheries and Aquatic Sciences 51, no. 12 (December 1, 1994): 2873–82. http://dx.doi.org/10.1139/f94-286.

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To determine if the density, biomass, species density (number of fish species per square metre), and species composition of juvenile and forage fish (fish ≤ 100 mm SL) differed among macrophyte types, we sampled fishes monthly from beds of Hydrilla verticillata, Panicum hemitomon, and Potamogeton illinoensis in two areas of Lake Okeechobee, Florida, from December 1989 to December 1990. Fish density and biomass differed significantly among the three macrophytes despite our design having relatively low statistical power to detect such differences. Densities and biomass were highest in H. verticillata (196 fish∙m−2, 30 g∙m−2), intermediate in P. hemitomon (60 fish∙m−2, 12 g∙m−2), and lowest in P. illinoensis (31 fish∙m−2, 6 g∙m−2). Trends among macrophytes were consistent throughout the year despite significant variation among months. Fish species density did not vary significantly among macrophyte types. However, the relative abundances of fishes differed significantly among macrophyte types. Patterns in fish abundance and relative species composition led us to infer that beds of different macrophyte types constitute distinct microhabitats for fish and structure the littoral zone of Lake Okeechobee into a mosaic landscape.
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20

Son, Se-Hwan, Soon-Jik Kwon, Ji-Hyeok Im, Seong-Ki Kim, Dongsoo Kong, and Jong-Yun Choi. "Aquatic Macrophytes Determine the Spatial Distribution of Invertebrates in a Shallow Reservoir." Water 13, no. 11 (May 22, 2021): 1455. http://dx.doi.org/10.3390/w13111455.

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Aquatic macrophytes determine the physical structure of many microhabitats in water and strongly influence the distribution of various aquatic animals. In this study, we analyzed the main microhabitat characteristics that affected the spatial distribution of invertebrates in shallow wetlands of South Korea (Jangcheok Reservoir). Environmental variables, macrophyte biomass, and invertebrate groups were used to analyze invertebrate distribution using a self-organizing map (SOM). Thirteen invertebrate groups were mapped onto the SOM, and each group was compared with the distribution of environmental variables and macrophyte biomass. Based on a U-matrix, five clusters were categorized according to Euclidean distance on the SOM. Invertebrate groups were closely related to macrophyte biomass. In particular, Lymnaeidae, Physidae, Viviparidae, Ecnomidae, and Hydrophilidae were abundant in quadrats with a high cover of Paspalum distichum and Nelumbo nucifera. Bithyniidae and Coenagrionidae were strongly associated with Trapa japonica and Hydrocharis dubia, whereas Planorbidae, Corduliidae, and Hydrophilidae were abundant with a high cover of Typha orientalis. Similar habitat preferences were found in a survey of gastropod distribution on the surface of each macrophyte species. The results clearly indicated that invertebrate distribution clusters were related to the spatial distribution of aquatic macrophytes in a shallow wetland.
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Rosenthal, Sadie K., Samantha S. Stevens, and David M. Lodge. "Whole-lake effects of invasive crayfish (Orconectes spp.) and the potential for restoration." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 6 (June 1, 2006): 1276–85. http://dx.doi.org/10.1139/f06-037.

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Effects of invasive species are often extrapolated to whole systems based on small-scale, short-term, and (or) single-system studies. For example, previous laboratory studies and in-lake cage experiments suggest that invasive crayfish Orconectes rusticus and O. propinquus reduce macrophyte and snail abundance in north temperate lakes, and snapshot lake surveys provide supporting evidence. Still, these impacts have not been demonstrated in multiple whole lakes over time. Thus, in summer of 2003, we resurveyed benthic invertebrates and macrophytes in lakes originally surveyed by the Michigan Department of Natural Resources in the late 1930s. Our multilake survey supports the macrophyte results from small-scale and comparative studies: macrophyte species richness and abundance declined significantly in invaded lakes relative to uninvaded lakes. We next conducted a laboratory seed-bank study to examine the potential for macrophyte restoration in a lake occupied by rusty crayfish for at least 15 years. Only two macrophyte species (Najas flexilis and Chara spp.) germinated from sediments from the invaded lake compared with eight species from reference sediments. This suggests that invaded lakes may have depauperate seed banks and that restoration of invaded macrophyte communities may require manual planting, even if crayfish could be removed.
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Stocks, Jerom R., Michael P. Rodgers, Joe B. Pera, and Dean M. Gilligan. "Monitoring aquatic plants: An evaluation of hydroacoustic, on-site digitising and airborne remote sensing techniques." Knowledge & Management of Aquatic Ecosystems, no. 420 (2019): 27. http://dx.doi.org/10.1051/kmae/2019016.

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Aquatic macrophytes are often monitored to detect change in ecosystem function and state, as well as assessing the effectiveness of invasive aquatic plant management. This study compares seven methodologies to monitor the distribution and abundances of aquatic macrophytes. Four line transect methodologies and three spatial mapping techniques were employed in parallel over a broad turbidity gradient in two lentic habitats of south-eastern Australia. The methodologies examined included hydroacoustic surveys, on-site digitising, and digitisation of airborne remote sensing imagery. Variation in estimates of macrophyte coverage were observed between methodologies. Consistency in the collection and interpretation of data was greatest for the line transect methodologies and the digitisation of satellite imagery. Duel-frequency identification sonar proved to be an effective novel hydroacoustic technique to monitor macrophyte abundances over broad spatial scales. Single beam sonar transects was also an objective, repeatable and scalable methodology. Videography and on-site handheld PDA mapping were of limited utility due to restrictions imposed by turbidity. The utility of sidescan sonar could be improved when used in conjunction with on-site handheld PDA mapping. This study outlines important considerations when selecting a methodology to monitor macrophyte distribution and abundance. Results indicate that no one specific method can be employed across all macrophyte monitoring studies. The method or combination of methods employed during macrophyte monitoring studies is dependent upon the study objectives, budget and environmental conditions of the study site.
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Pelicice, Fernando Mayer, Sidinei Magela Thomaz, and Angelo Antonio Agostinho. "Simple relationships to predict attributes of fish assemblages in patches of submerged macrophytes." Neotropical Ichthyology 6, no. 4 (December 2008): 543–50. http://dx.doi.org/10.1590/s1679-62252008000400001.

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Submerged macrophytes play an important role in structuring habitats and, therefore, in determining patterns of aquatic biodiversity. Because these plants are widespread in shallow areas of many Neotropical reservoirs, the present work investigated if variables related to habitat structure, measured in patches of submerged macrophytes (Egeria densa and E. najas), can be used to predict fish assemblage attributes (fish density and species richness). Based on patch characteristics at fine spatial extents (macrophyte patches within reservoir arms), we considered plant biomass, volume and proportional volume (i.e. percentage of macrophyte volume in the water column) as potential predictors. Fish and macrophytes were sampled with a 1-m² throw trap in littoral habitats of Rosana Reservoir, Paranapanema River, and simple correlation analyses were performed. Fish richness and abundance were highly correlated with all variables (R = 0.53 to 0.90), a relationship consistently observed in all sites. When compared to biomass, plant volume and proportional volume did not yield stronger correlations. We observed stronger correlations when E. densa and E. najas patches were analyzed separately (mono-specificity), probably because particular effects of each macrophyte on habitat structuring were removed (e.g. unnoticed morphological differences or unknown effects on habitat quality). The high R values observed in all pairwise relationships are uncommon in ecological studies, highlighting the predictive potential of variables related to habitat structure. These results suggest that, at small spatial extents, macrophyte biomass may represent an interesting predictor of fish density and richness in reservoirs with extensive colonization of submerged plants.
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Fischel, Andrea, Marit-Solveig Seidenkrantz, and Bent Vad Odgaard. "Benthic foraminiferal assemblages and test accumulation in coastal microhabitats on San Salvador, Bahamas." Journal of Micropalaeontology 37, no. 2 (November 14, 2018): 499–518. http://dx.doi.org/10.5194/jm-37-499-2018.

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Abstract. Benthic foraminiferal populations were studied in a shallow bay of San Salvador Island, the Bahamas. Surface sediments and marine macrophytes were collected from 14 sample sites along a 500 m transect at Grahams Harbour to investigate the foraminiferal assemblage in each microhabitat and to test the link between dead foraminiferal test accumulation patterns and living epiphytic and sedimentary foraminiferal assemblages, macrophyte distribution, and environmental gradients. The analyses include grain size measurements, macrophyte biomass quantification, and qualitative and quantitative studies of benthic foraminifera. The foraminifera found attached to macrophytes differed between macrophyte habitats. However, a correlation between these living communities and the dead assemblages in the sediments at the same sites could not be observed. Principal component analysis (PCA) and redundancy analysis (RDA) suggest that the presence of the macroalgae Halimeda explains 16 % of the residual faunal variation in the dead foraminiferal assemblage after the effects of sorting according to fall speed are partialled out. The RDA also reflects a positive correlation between foraminifera larger than 1.0 mm in diameter and the 0.25–0.5 mm sediment grain size, indicating sedimentological processes as the main factor controlling the sedimentary epiphytic foraminiferal assemblages. These sedimentary processes overprint most effects of ecological features or macrophyte-specific association.
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Temmink, Ralph J. M., Martijn Dorenbosch, Leon P. M. Lamers, Alfons J. P. Smolders, Winnie Rip, Wouter Lengkeek, Karin Didderen, Gregory S. Fivash, Tjeerd J. Bouma, and Tjisse van der Heide. "Growth forms and life-history strategies predict the occurrence of aquatic macrophytes in relation to environmental factors in a shallow peat lake complex." Hydrobiologia 848, no. 17 (May 27, 2021): 3987–99. http://dx.doi.org/10.1007/s10750-021-04618-6.

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AbstractAquatic ecosystems provide vital services, and macrophytes play a critical role in their functioning. Conceptual models indicate that in shallow lakes, plants with different growth strategies are expected to inhabit contrasting habitats. For shallow peat lakes, characterized by incohesive sediments, roles of growth forms, life-history strategies and environmental factors in determining the occurrence of aquatic vegetation remain unknown. In a field survey, we sampled 64 points in a peat lake complex and related macrophyte occurrence to growth forms (floating-leaved rooted and submerged), life-history strategies for overwintering (turions, seeds, rhizomes) and environmental factors (water depth, fetch, and porewater nutrients). Our survey showed that macrophyte occurrence relates to water depth, wind-fetch, and nutrients, and depends on growth form and life-history strategies. Specifically, rooted floating-leaved macrophytes occur at lower wind-fetch/shallower waters. Submerged macrophytes occur from low to greater wind-fetch/water depth, depending on life-history strategies; macrophytes with rhizomes occur at greater wind-fetch/depth relative to species that overwinter with seeds or turions. We conclude that growth form and life-history strategies for overwintering predict macrophytes occurrence regarding environmental factors in peat lakes. Therefore, we propose an adapted model for macrophyte occurrence for such lakes. Altogether, these results may aid in species-selection to revegetate peat lakes depending on its environment.
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Bini, L. M., L. G. Oliveira, D. C. Souza, P. Carvalho, and M. P. Pinto. "Patterns of the aquatic macrophyte cover in Cachoeira Dourada Reservoir (GO-MG)." Brazilian Journal of Biology 65, no. 1 (February 2005): 19–24. http://dx.doi.org/10.1590/s1519-69842005000100004.

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The relationship between the aquatic macrophyte cover in upper segments of tributaries and this cover in these tributaries but near the reservoir's main body was tested. Sixteen taxa belonging to 12 families of aquatic macrophytes were recorded in Cachoeira Dourada Reservoir. The most frequent species were Eichhornia azurea (frequency of occurrence = 92%; n = 37 sites) and E. crassipes (44%). Upper segments of the tributaries were the main areas colonized by these aquatic macrophytes. The positive relationship between the aquatic macrophyte cover between the upper and lower segments of tributaries indicates the importance of dispersion in the colonization of the arms and the reservoir's main body.
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Ray, A. M., A. J. Rebertus, and H. L. Ray. "Macrophyte succession in Minnesota beaver ponds." Canadian Journal of Botany 79, no. 4 (April 1, 2001): 487–99. http://dx.doi.org/10.1139/b01-018.

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Beavers (Castor canadensis Kuhl.) are keystone species that dramatically alter nutrient cycles and food webs in aquatic and terrestrial ecosystems by modifying their hydrology and selectively removing riparian trees. We documented macrophyte succession in 36 beaver ponds ranging from 4 to over 40 years old. We used impounded bogs, because they were isolated from other waterbodies and less prone to washout. Richness and diversity increased linearly in ponds during the first four decades. Pond age and the product of pond size and the number of neighboring ponds in a 0.25-km radius explained 64% (p = 0.001) of the variation in richness. Compositional trends were best explained by propagule dispersal traits. Initial colonists included vagile species, like free-floating macrophytes and desirable foods for waterfowl, like the narrow-leaved pondweeds. Ponds of intermediate age (11–40 years) had the highest diversity, with both floating-leaved and submersed life forms represented. Two community types were identified in older ponds: one characterized by dense lily pad cover and the other characterized by a rich assemblage of Potamogeton. By developing a predictive model for macrophyte succession in beaver ponds, we provide a basis for studying a variety of ecological processes and organisms that depend on macrophytes in these regionally abundant habitats.Key words: macrophyte, succession, beaver, bogs, Minnesota, pond.
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28

Carter, D. R., S. Carter, and J. L. Allen. "Submerged Macrophyte Control Using Plastic Blankets." Water Science and Technology 29, no. 4 (February 1, 1994): 119–26. http://dx.doi.org/10.2166/wst.1994.0172.

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Penrith Lakes Scheme is concerned with the rehabilitation of gravel pits to create a system of large recreational lakes. A potential submerged macrophyte problem has been identified in an existing man-made lake. The need to control the macrophytes is dependent on the proposed end use of the lakes and the potential area of invasion. A variety of control options were assessed. Plastic blankets were tested to determine their effectiveness in controlling macrophyte growth specifically in swimming and boat access areas. Comparisons of clear, black and black woven blankets were conducted. Experiments revealed that 90% of the plants under the black and black woven blankets died within six weeks. Under clear blankets plants were reduced by between 20%-90%. Analysis showed that significant interactions occurred between sites and treatments and times, from which it can be inferred that none are independent of each other. Success in the reduction of macrophytes appears dependent on such factors as plant species, sediment accumulation and light reduction.
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Zhenbin, Wu, Xia Yicheng, Deng Jiaqi, Kuang Qijun, Zhan Facui, and Chen Xitao. "Studies on Wastewater Treatment by Means of Integrated Biological Pond System: Design and Function of Macrophytes." Water Science and Technology 27, no. 1 (January 1, 1993): 97–105. http://dx.doi.org/10.2166/wst.1993.0025.

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A biological treatment pond system to purify municipal wastewater from a medium-sized city has been operated for 3 years and gained good results, Macrophytes took a very important part in this system. The macrophyte ponds and zones were designed spacially and periodically different to test their purification efficiencies. The purifing system was divided into three functional zones: purifing zone, effluent upgrading zone and multi-utilization zone. Macrophytes were planted in several subzones in series in some ponds. The experiments showed that the multi-macrophyte zone system revealed greater purification efficiencies than those of traditional oxidation ponds as well as general macrophyte ponds. The system reached high reductions of COD, BOD, TSS, TN and TP.The activity of mutagenic agents and numbers of virus and bacteria were significantly decreased during the process of purification. The effluent fron the system was greatly upgraded and could be used in fishery and agriculture. The harvested macrophytes from the purifing zone and effluent upgrading zone could be put into the multi-utilization zone as feed, fertilizer, biogas, etc. The idea of resourcization of wastewater was being put into practice. The studies also showed that some macrophytes revealed strong ability to inhibit algae growth not because of light, nutrient and space competition. These results had been used in the treatment system design and gained expected effeets. Plant harvesting did not yield dramatic effects on reductions of the main pollutants, though it did affect remarkably the biomass productivity of the macrophytes.
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Bubíková, Kateřina, and Richard Hrivnák. "Relationships of macrophyte species richness and environment in different water body types in the Central European region." Annales de Limnologie - International Journal of Limnology 54 (2018): 35. http://dx.doi.org/10.1051/limn/2018027.

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Individual types of waterbodies are characterised by their specific environmental conditions controlling growth of aquatic macrophytes. We focused on effects of environmental factors on macrophyte species richness in canals, ponds, rivers and streams within Central European region. We employed generalised linear models (GLM) to assess separately overall macrophyte species data and data on wetland species (true aquatic plants and helophytes). No significant difference was revealed by comparing species richness among water body types, though canals were the richest water bodies and streams supported the lowest diversity of macrophytes. The models for all the waterbodies, except streams, contained at least two variables and the explained variability ranged from 37% to 77%. The most recurring variables were the coverage of fine substrate, turbidity, shading by bank and shore trees and shrubs, and altitude. Nevertheless, no obvious pattern of factors was observed for particular water body types. Our study confirmed that aquatic macrophyte species richness is shaped by a complexity of factors and necessity of targeting survey and further generalisation of results not only on one specific water body.
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Moura-Falcão, Rafael Henrique de, Ariadne do Nascimento Moura, and Cihelio Alves Amorim. "Growth of Microcystis strains isolated from environments with the presence and absence of submerged macrophytes in coexistence with Ceratophyllum demersum." Acta Scientiarum. Biological Sciences 43 (November 30, 2021): e57734. http://dx.doi.org/10.4025/actascibiolsci.v43i1.57734.

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Cyanobacterial blooms can cause severe ecological and health problems in drinking water reservoirs. To alleviate this problem, allelopathically active submerged macrophytes can be used to reduce cyanobacterial growth. Accordingly, this study aimed to evaluate the sensitivity of strains of the Microcystis aeruginosa complex isolated from reservoirs with the presence and absence of submerged macrophytes to the allelochemicals of Ceratophyllum demersum. A coexistence experiment was carried out between the submerged macrophyte C. demersum and four Microcystis strains, with two treatments for each strain, one in coexistence with the submerged macrophyte (7 g L-1) and control (in the absence of the macrophyte). Two strains of M. aeruginosa (BMIUFRPE-06 and BMIUFRPE-07) and two of M. panniformis (BMIUFRPE-08 and BMIUFRPE-09) were used, which were isolated from Cajueiro (with submerged macrophytes) and Tapacurá (without submerged macrophytes) reservoirs, respectively. The biomass of Microcystis strains from the reservoir without macrophytes (BMIUFRPE-08 and BMIUFRPE-09) was significantly inhibited in 96% (T-test: p < 0.01) and 74% (T-test: p< 0.05), when compared to the control, respectively, with lower values of growth rates (ANOVA: p < 0.05). The strains isolated from the reservoir with macrophytes (BMIUFRPE-06 and BMIUFRPE-07) showed a growth delay (biomass reductions of 44 and 58%, respectively) in the coexistence treatment but without significant difference from the control on the sixth day of the experiment (biomass - T-test: p > 0.05; growth rate - ANOVA: p > 0.05). These results suggest that strains isolated from environments with submerged macrophytes are less sensitive to allelochemicals of these plants, as these strains may be adapted to the coexistence with submerged macrophytes.
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Hrivnák, Richard, Helena Oťaheľová, and Dušan Gömöry. "Seasonal dynamics of macrophyte abundance in two regulated streams." Open Life Sciences 4, no. 2 (June 1, 2009): 241–49. http://dx.doi.org/10.2478/s11535-009-0004-6.

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AbstractThis study analysed seasonal dynamics of macrophyte abundance in two perennial lowland regulated streams (Stream 1 and 2) in the Danube basin (Slovakia). Assessments of macrophyte abundance and environmental characteristics were accomplished 7 times during the vegetation period in 2005 within a 100 m long section. Statistically significant differences in total abundance of macrophytes as well as an abundance of macrophyte groups (hydrophytes, amphiphytes, helophytes) and Potamogeton nodosus were detected among months within the vegetation period. Abundance fluctuations for individual macrophyte groups and species were moderate in Stream 1 and much stronger in Stream 2. Only amphiphytes showed bimodal temporal distribution in Stream 1, but the abundance of this group was low, reflecting more or less random occurrence of species in vegetation period. Multiple linear regression revealed that water depths and air temperature are the most significant environmental variables affecting the seasonal pattern of total as well as dominating group abundance in Stream 1 and 2, respectively. In all cases, abundances are significantly influenced by the abundance of the respective group in the preceding month. Culmination time differed between streams for all macrophyte groups except helophytes. Total abundance culminated 0.57 month later in the Stream 1 compared to Stream 2.
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Damtew, Yohannes Tefera, Boud Verbeiren, Aymere Awoke, and Ludwig Triest. "Satellite Imageries and Field Data of Macrophytes Reveal a Regime Shift of a Tropical Lake (Lake Ziway, Ethiopia)." Water 13, no. 4 (February 3, 2021): 396. http://dx.doi.org/10.3390/w13040396.

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Lake Ziway is one of the largest freshwater lakes located in the central Ethiopian rift valley. The lake shoreline is dominated by macrophytes which play an important role in immobilizing run-off pollution, stabilize sediments and support biodiversity. Monitoring the spatio-temporal changes of great lakes requires standardized methods. The aim of this study was to assess the current and long-term trends of macrophyte distribution, surface water area and the water level of Lake Ziway using remote sensing images from 1986 to 2016 with additional hydro-meteorological data. A supervised image classification with classification enhancement using Normalized Difference Aquatic Vegetation Index (NDAVI) and Normalized Difference Vegetation Index (NDVI) was applied. The classification based on NDAVI revealed eight target classes which were identified with an overall producer’s accuracy of 79.6%. Contemporary open water and macrophyte fringes occupied most of the study area with a total area of 407.4 km2 and 60.1 km2, respectively. The findings also revealed a regime shift in the mean water level of the lake and a decline in macrophyte distribution. The long-term water surface area of Lake Ziway also decreased between 1986 and 2016. The changes in water level could be explained by climate variability in the region and strong anthropogenic disturbance. A decline in water level was also associated with lowered surface water area, lakeward retreated macrophyte fringes and enhanced landward encroachment of mudflats, and resulted in a succession of macrophytes with semi-terrestrial vegetations.
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Ghirardi, Nicola, Mariano Bresciani, Gary Free, Monica Pinardi, Rossano Bolpagni, and Claudia Giardino. "Evaluation of Macrophyte Community Dynamics (2015–2020) in Southern Lake Garda (Italy) from Sentinel-2 Data." Applied Sciences 12, no. 5 (March 4, 2022): 2693. http://dx.doi.org/10.3390/app12052693.

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Macrophytes are of fundamental importance to the functioning of lake ecosystems. They provide structure, habitat, and a food source and are a required component in monitoring programs of lake ecological quality. The key aim of this study is to document the variation in spatial extent and density of macrophytes seasonally between 2015 and 2020 of the Sirmione Peninsula (Lake Garda, Italy), using Sentinel-2 imagery. In addition to this, our results were compared to previous data from imaging spectrometry; individual parameters affecting macrophyte communities were tested, and the possible effect of the COVID-19 lockdown on macrophyte colonization was evaluated. Satellite images allowed the mapping of the spatiotemporal dynamics of submerged rooted macrophytes in order to support monitoring of the shallow water ecosystem under study. Substantial changes were found in both spatial extent and density over the period from 2015 to 2020, particularly in 2019 when there was almost a complete absence of dense macrophytes. Variables found to influence the amount of macrophytes included transparency, chlorophyll–a, water level, winter wave height, and grazing by herbivores. A separate analysis focusing on areas associated with boat transit found a recovery in macrophyte coverage during the period of COVID-19 lockdown. The outcome of the study highlights a decline in the density of the macrophytes and a shift towards deeper areas compared to the situation in 1997. The area examined is part of an internationally important site containing the highest abundance and diversity of overwintering water birds in Italy. Exploiting satellite data at high frequency provided an insight to understand the dynamic changes and interactions with herbivorous birds, environmental factors, and anthropogenic pressures, revealing a delicately balanced and threatened ecosystem.
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Lumpkin, Will P., Kincade R. Stirek, and Lee A. Dyer. "Macrophyte Diversity and Complexity Reduce Larval Mosquito Abundance." Journal of Medical Entomology 57, no. 4 (February 1, 2020): 1041–48. http://dx.doi.org/10.1093/jme/tjaa012.

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Abstract The role of aquatic arthropod diversity and community interactions of larval mosquitoes are important for understanding mosquito population dynamics. We tested the effects of aquatic macrophyte diversity and habitat structural complexity in shaping the predator and competitor invertebrate communities associated with mosquito larvae. Experimental mesocosms were planted with live aquatic macrophytes and allowed to be naturally colonized by local invertebrates. Results indicated a positive effect of macrophyte diversity on competitor diversity and a negative effect on predator diversity. In turn, predator diversity negatively impacted mosquito abundance through a direct effect, while competitor diversity showed an indirect negative effect on mosquito larval abundance through its positive effect on predator diversity. The enhancement of aquatic macrophyte diversity and structural complexity has practical applications for the reduction of mosquito populations in managed systems where complete source elimination is not possible.
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Buseva, Zh F., Gazerani Farahani, Yu K. Veras, A. A. Kolmakova, and N. N. Sushchik. "STOICHIOMETRIC COMPOSITION OF SESTON IN LITTORAL AND PELAGIAL ZONES OF SHALLOW LAKE OBSTERNO (BELARUS)." Doklady of the National Academy of Sciences of Belarus 62, no. 3 (June 30, 2018): 304–10. http://dx.doi.org/10.29235/1561-8323-2018-62-3-304-310.

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We estimated the seston elemental composition (C, N, P) and its ratio in pelagic and littoral zones of mesotrophic shallow Lake Obsterno during two contrasting seasons, as well as the influence of macrophyte beds on the seston stoichiometry. In the both pelagial and littoral zones in summer the C: N ratio was small, 4.62 and 7.05 respectively. But it increased slightly during autumn to 5.66 in pelagic samples against 8.33 in littoral ones. The large N : P ratio and the small phosphorus content specially in the macrophyte covered littoral zone equal to 57.7 in July against 22.47 in September suggest a high level of phosphorus limitation in the littoral locations as a possible mediated reason suppressing zooplankton abundance in sumabundance in sum in summer. Our results in the both pelagial and littoral habitat showed a highly P limited situation in which the N : P ratio was larger in littoral with macrophyte than in pelagial zones. The obtained data of littoral seston stoichiometry were recorded for the first time and exceeded the classical Redfield ratio. The elemental imbalance between macrophyte covered littoral and pelagial suggest that nutrients, especially P, are more limiting in macrophyte beds in summer due to the resource competition between phytoplankton and macrophytes for nutrients, a poor food quality, low zooplankton abundance, as well as its poor taxon-specific elemental ratio in summer.
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Xu, Z. H., X. A. Yin, and Z. F. Yang. "An optimisation approach for shallow lake restoration through macrophyte management." Hydrology and Earth System Sciences 18, no. 6 (June 17, 2014): 2167–76. http://dx.doi.org/10.5194/hess-18-2167-2014.

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Abstract. Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of a lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality), rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area) and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.
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Xu, Z. H., X. A. Yin, and Z. F. Yang. "An optimisation approach for shallow lake restoration through macrophyte management." Hydrology and Earth System Sciences Discussions 11, no. 1 (January 16, 2014): 807–32. http://dx.doi.org/10.5194/hessd-11-807-2014.

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Abstract. Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality), rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area) and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.
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Lewin, Iga, and Krzysztof Szoszkiewicz. "Drivers of macrophyte development in rivers in an agricultural area: indicative species reactions." Open Life Sciences 7, no. 4 (August 1, 2012): 731–40. http://dx.doi.org/10.2478/s11535-012-0053-0.

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AbstractThe ecological drivers of macrophyte development in a lowland agricultural area were tested based on a 2008 survey on the Wkra River catchment. Our survey was carried out in the rivers of an agricultural area with relatively high concentrations of both nitrates and phosphates in the water. By using the Polish macrophyte method, we were able to calculate several botanical metrics. Canonical ordination analyses used to relate biological data to environmental variables such as physical and chemical parameters of water, surface water velocity or river width, were carried out using CANOCO for Windows. Redundancy analysis (RDA) showed that pH and alkalinity were the parameters best correlated with the distribution of macrophytes and values of macrophyte indices. The recorded values of the Macrophyte Index for River in the Wkra River and its tributaries reflected their good and moderate ecological status (the Water Framework Directive scale). Despite the fact that nutrient concentrations in the water were relatively high and that most of the sites represented eutrophic conditions, the results of this survey showed that non-nutrient parameters may play an important role in explaining aquatic plant occurrence in rivers that have been subjected to eutrophication.
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40

CRUZ, C., A. F. SILVA, F. P. VENTURINI, N. GARLICH, R. L. C. M. PITELLI, and R. A. PITELLI. "FOOD PREFERENCE AND CONSUMPTION OF AQUATIC MACROPHYTES SUBMERGED BY SNAIL Pomacea canaliculata." Planta Daninha 33, no. 3 (September 2015): 433–39. http://dx.doi.org/10.1590/s0100-83582015000300006.

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ABSTRACTThe objective of this study was to evaluate the consumption potential, food preference and use of snail Pomacea canaliculata as a biocontrol agent of four submerged aquatic macrophytes (Ceratophyllumdemersum, Egeriadensa, Egerianajas and Hydrilla verticillata). Two experiments were performed. In the first experiment, the introduction of a snail took place and 10 grams of each macrophyte in plastic containers with 1 liter of water. The assessments of consumption by the snail were performed at each 48 hours, during 12 days. The second experiment was performed in 600 liters microcosms containing five snails in each experimental unit. Fifty grams of each macrophyte were offered the snails at the same time, adding the same amounts after seven, 14, 21 and 30 days. On both trials, the most consumed macrophyte by the P.canaliculata was H.verticillata (7.64 ± 1.0 g 48 h and 50 ± 0.18 g) respectively, significantly differing from the others. However, in the absence of H.verticilata, E.najas and E.densa were consumed. The preference of P.canaliculata for H.verticillata is very interesting, because this plant is exotic and problematic in Brazil, and the snail is one more tool for biological management of submerged aquatic macrophyte H.verticillata.
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41

Van Goethem, Ryan R., Casey J. Huckins, and Amy M. Marcarelli. "Effects of Invasive Watermilfoil on Primary Production in Littoral Zones of North-Temperate Lakes." Diversity 12, no. 2 (February 19, 2020): 82. http://dx.doi.org/10.3390/d12020082.

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Species invasions are changing aquatic ecosystems worldwide. Submerged aquatic macrophytes control lake ecosystem processes through their direct and indirect interactions with other primary producers, but how these interactions may be altered by macrophyte species invasions in temperate lakes is poorly understood. We addressed whether invasive watermilfoil (IWM) altered standing crops and gross primary production (GPP) of other littoral primary producers (macrophytes, phytoplankton, attached algae, and periphyton) in littoral zones of six Michigan lakes through a paired-plot comparison study of sites with IWM (standardized abundance 7–56%) compared to those with little or no IWM (standardized abundance 0–2%). We found that primary producer standing crops and the GPP of epiphytes, phytoplankton, and benthic periphyton were variable among lakes and not significantly different between paired study plots. Macrophyte standing crops predicted rates of benthic periphyton GPP, and standing crops of all other primary producers across all study plots. Overall, our results suggest that the effects of IWM on other primary producers in littoral zones may be lake-specific, and are likely dependent on the density of IWM, or whether it is functionally similar to other native species that it replaces or co-exists with. Moreover, in lakes where IWM is established but does not dominate macrophyte assemblages, the effects on littoral zone productivity may be minimal. Instead, overall macrophyte biomass is the primary factor controlling the rates of production and biomass of the other littoral zone primary producers, as has long been understood and observed in lake ecosystems.
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42

Stephan, Lígia R., Beatrix E. Beisner, Samuel G. M. Oliveira, and Maria Stela M. Castilho-Noll. "Influence of Eichhornia crassipes (Mart) Solms on a Tropical Microcrustacean Community Based on Taxonomic and Functional Trait Diversity." Water 11, no. 11 (November 19, 2019): 2423. http://dx.doi.org/10.3390/w11112423.

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Macrophytes are important structural attributes of freshwater ponds and wetlands, affecting zooplankton community composition. One of the best-known macrophytes in the world is Eichhornia crassipes, which, due to its high reproductive rate, can quickly occupy large areas of aquatic environments. However, there have been few assessments of the direct effect of this macrophyte, in the absence of predators, for tropical zooplankton communities. The aim of this study was to evaluate the influence of E. crassipes on microcrustacean community structure using species and functional diversity, the latter providing an important tool to evaluate the response to changes in resource availability along an environment gradient. We also evaluated which functional traits were favored when the structural niche offered by submerged parts of the macrophytes was present. We conducted a 30 day mesocosm experiment (117 m3) with and without the presence of floating macrophytes (Eichhornia crassipes) inserted along one edge of the mesocosms. Treatment effects on microcrustacean density and community structure using taxonomic and functional classification approaches were assessed. There was a positive association between macrophyte presence and microcrustacean diversity for both diversity types, showing that the presence of macrophytes enhanced the niche availability for the microcrustacean community, likely through changes to resource diversity through habitat structure provision. In the presence of macrophytes, the abundance of species with the following feeding traits increased: burrowing, benthic habitat preference, and herbivore–detritivore and omnivore–carnivore trophic groups. Results showed that the species capable of using the niche offered by submerged macrophyte structures had benthic traits, enabling their co-existence with species possessing primarily pelagic traits. Using a functional approach, our study demonstrated that Eichhornia crassipes can structure microcrustacean communities and promote diversity, likely via increased habitat diversity, which enables the co-existence of species possessing different adaptations to acquiring resources available in the environment.
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43

Gichuki, John, Reuben Omondi, Priscillar Boera, Tom Okorut, Ally Said Matano, Tsuma Jembe, and Ayub Ofulla. "Water HyacinthEichhornia crassipes(Mart.) Solms-Laubach Dynamics and Succession in the Nyanza Gulf of Lake Victoria (East Africa): Implications for Water Quality and Biodiversity Conservation." Scientific World Journal 2012 (2012): 1–10. http://dx.doi.org/10.1100/2012/106429.

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This study, conducted in Nyanza Gulf of Lake Victoria, assessed ecological succession and dynamic status of water hyacinth. Results show that water hyacinth is the genesis of macrophyte succession. On establishment, water hyacinth mats are first invaded by native emergent macrophytes,Ipomoea aquaticaForsk., andEnydra fluctuansLour., during early stages of succession. This is followed by hippo grassVossia cuspidata(Roxb.) Griff. in mid- and late stages whose population peaks during climax stages of succession with concomitant decrease in water hyacinth biomass. Hippo grass depends on water hyacinth for buoyancy, anchorage, and nutrients. The study concludes that macrophyte succession alters aquatic biodiversity and that, since water hyacinth infestation and attendant succession are a symptom of broader watershed management and pollution problems, aquatic macrophyte control should include reduction of nutrient loads and implementing multifaceted approach that incorporates biological agents, mechanical/manual control with utilization of harvested weed for cottage industry by local communities.
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44

Singh, R. P., Ying He Jiang, and Xiao Peng Wen. "Phosphorus Removal Efficiency of Different Media and Macrophyte in Constructed Wetland." Advanced Materials Research 113-116 (June 2010): 2368–72. http://dx.doi.org/10.4028/www.scientific.net/amr.113-116.2368.

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Constructed wetlands are very useful for the removal of nutrients from treated municipal wastewater. Use of different kinds of media and macrophytes improves the efficiency of nutrient removal of constructed wetlands. Three different media (pulverized ash bricks, shale and gravel) and common reed (Phragmites spp.) were used for present research work. This macrophyte is a local weed and easily available. Uses of different media with macrophyte are very efficient for nutrient removal from treated municipal wastewater. Out of these three media used for present research pulverized fly ash bricks media was most efficient for removal of phosphorus in constructed wetland.
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45

Thomaz, SM, P. Carvalho, AA Padial, and JT Kobayashi. "Temporal and spatial patterns of aquatic macrophyte diversity in the Upper Paraná River floodplain." Brazilian Journal of Biology 69, no. 2 suppl (June 2009): 617–25. http://dx.doi.org/10.1590/s1519-69842009000300016.

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Although the importance of long-term data has been emphasized by ecologists in recent years, little is known about how communities may change over time. In this study, we describe the general patterns of aquatic macrophyte diversity in the Paraná River floodplain observed during six years of study. Temporal changes in community composition were also evaluated. Data on the presence or absence of aquatic macrophytes were collected between March 2002 and March 2008, in six lakes associated with three rivers. Different analytical strategies were used to evaluate the dynamics of aquatic macrophyte communities between the different systems in the floodplain. The composition of aquatic macrophytes differed among the rivers, mainly with respect to the different vegetation life forms (floating, submersed, emergent and rooted with floating stems). The temporal similarity of species composition during the six years and the beta-diversity index indicated that the month-to-month species turnover was, in general, lower in the connected lakes, which are directly influenced by the river. Probably the water level fluctuation is a selective force that contributes to maintaining diversity or richness. Our findings indicated the importance of abiotic characteristics and connectivity of the lakes in determining macrophyte composition and community stability over a long time frame.
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46

Gillefalk, Mikael, Christiane Herzog, and Sabine Hilt. "Phosphorus Availability and Growth of Benthic Primary Producers in Littoral Lake Sediments: Are Differences Linked to Induced Bank Filtration?" Water 11, no. 5 (May 27, 2019): 1111. http://dx.doi.org/10.3390/w11051111.

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Submerged macrophytes and periphyton are benthic primary producers that play an important role for several ecosystem functions of lakes. Their growth often depends on the availability of phosphorus (P) in sediments and overlying water. This P availability is assumed to potentially be affected by induced bank filtration (IBF), a cost-effective method for drinking water production. In this study, we tested whether littoral sediments sampled at sites with high and low influence of IBF in a temperate eutrophic lake used for bank filtration since more than 100 years affects periphyton and macrophyte growth. Sediments differed in aerobic desorbed water-soluble phosphorus (PH2O) and iron (Fe) content and the growth of macrophytes in sediments with a high impact of IBF was lower compared to sediments with low impact of IBF. We also found that P addition to the nutrient solution increased periphyton growth and that periphyton limited macrophyte growth. While these results point to a potential impact of IBF on P availability in sediments that can cascade to benthic primary producers, we could not prove mechanistic links between high rates of IBF and the lower macrophyte growth. Additional research to assure a sustainable application of this valuable drinking water production method is therefore needed.
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47

Bravo, Isabel, Francisco Rodríguez, Isabel Ramilo, and Julio Afonso-Carrillo. "Epibenthic Harmful Marine Dinoflagellates from Fuerteventura (Canary Islands), with Special Reference to the Ciguatoxin-Producing Gambierdiscus." Journal of Marine Science and Engineering 8, no. 11 (November 12, 2020): 909. http://dx.doi.org/10.3390/jmse8110909.

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The relationship between the ciguatoxin-producer benthic dinoflagellate Gambierdiscus and other epibenthic dinoflagellates in the Canary Islands was examined in macrophyte samples obtained from two locations of Fuerteventura Island in September 2016. The genera examined included Coolia, Gambierdiscus, Ostreopsis, Prorocentrum, Scrippsiella, Sinophysis, and Vulcanodinium. Distinct assemblages among these benthic dinoflagellates and preferential macroalgal communities were observed. Vulcanodinium showed the highest cell concentrations (81.6 × 103 cells gr−1 wet weight macrophyte), followed by Ostreopsis (25.2 × 103 cells gr−1 wet weight macrophyte). These two species were most represented at a station (Playitas) characterized by turfy Rhodophytes. In turn, Gambierdiscus (3.8 × 103 cells gr−1 wet weight macrophyte) and Sinophysis (2.6 × 103 cells gr−1 wet weight macrophyte) were mostly found in a second station (Cotillo) dominated by Rhodophytes and Phaeophytes. The influence of macrophyte’s thallus architecture on the abundance of dinoflagellates was observed. Filamentous morphotypes followed by macroalgae arranged in entangled clumps presented more richness of epiphytic dinoflagellates. Morphometric analysis was applied to Gambierdiscus specimens. By large, G. excentricus was the most abundant species and G. australes occupied the second place. The toxigenic potential of some of the genera/species distributed in the benthic habitats of the Canary coasts, together with the already known presence of ciguatera in the region, merits future studies on possible transmission of their toxins in the marine food chain.
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48

Peternel, Andrej, Alenka Gaberščik, Igor Zelnik, Matej Holcar, and Mateja Germ. "Long-Term Changes in Macrophyte Distribution and Abundance in a Lowland River." Plants 11, no. 3 (January 31, 2022): 401. http://dx.doi.org/10.3390/plants11030401.

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The aim of this study was to reveal the changes of macrophyte community over time and along the course of the Ižica River. In 1996, 2000, and 2016, we surveyed the distribution and abundance of macrophyte species in the lowland Ižica River, which originates in the town of Ig and then flows through an agricultural landscape. We calculated the River Macrophyte Index (RMI), which reflects the ecological status of the river. In 2016, ecomorphological conditions of the river, using the Riparian, Channel and Environmental inventory, were also assessed. In just 10.5 km of the river, we identified 27 taxa of macrophytes, among which Potamogeton natans, Sagittaria sagittifolia, and P. perfoliatus were the most abundant. Detrended correspondence analysis showed that, in 1996, the surveyed stretches differed more according to macrophyte composition than in the following years. The assessed environmental parameters explained 43% of the variability of the macrophyte species; riverbank stability explained 20%, riverbed structure 10%, while vegetation type of the riparian zone and bottom type explained 7 and 5%, respectively. The species composition of the macrophyte community revealed significant changes over the years of the riverine ecosystem. Comparison of RMIs in 1996 revealed better conditions in the upper and middle part of the river, while in 2016, the situation was the opposite, since the conditions in the upper part deteriorated significantly over time, while the lower part of the river had the best ecological status. These changes may be due to a considerable increase in the population of the settlement Ig, while better status in the lower course of the river may be a consequence of improvements in the infrastructure and the use of sustainable agricultural practices in the catchment due to the establishment of a formal area of protection.
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49

Klein, J. C., and M. Verlaque. "Experimental removal of the invasive Caulerpa racemosa triggers partial assemblage recovery." Journal of the Marine Biological Association of the United Kingdom 91, no. 1 (July 5, 2010): 117–25. http://dx.doi.org/10.1017/s0025315410000792.

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The invasive species Caulerpa racemosa var. cylindracea represents a serious threat to the diversity of benthic assemblages in the Mediterranean Sea. In the present study, a removal experiment was carried out to test whether, after 18 months of C. racemosa var. cylindracea exclusion, the macrophyte assemblage resembled a non-invaded assemblage. The results show that in the assemblage invaded by C. racemosa var. cylindracea the number of species, macrophyte cover, Shannon diversity and Pielou's evenness were lower than in the non-invaded assemblage. Erect perennial species were particularly affected and other introduced species were significantly reduced or completely excluded. After 18 months of removal/exclusion of C. racemosa var. cylindracea, only partial recovery of the macrophyte assemblage could be observed. Species numbers, total cover and erect perennial species cover were still significantly lower than in the non-invaded plots. However Shannon diversity and Pielou's evenness had reached comparable levels. In contrast to native macrophytes, the total cover of other introduced species reached a level comparable to the non-invaded plots. In summary, the present study revealed that after 18 months of C. racemosa var. cylindracea exclusion: (i) only partial recovery of the macrophyte assemblage occurred; and (ii) the development of other invasive species was favoured by the absence of C. racemosa var. cylindracea (Sisyphus effect).
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50

Wehr, John D., Dale A. Holen, Molli M. MacDonald, and Sean P. Lonergan. "Effects of different organic carbon sources on a freshwater plankton community." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 9 (September 1, 1998): 2150–60. http://dx.doi.org/10.1139/f98-098.

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We examined effects of terrestrial and aquatic detritus on optical, chemical, and biological properties of a planktonic food web in mesotrophic Calder Lake, New York. The 5400-L mesocosms received detritus from terrestrial leaves or aquatic macrophytes (added 1-2 mg dissolved organic C/L). Terrestrial detritus had significant effects on UV-B absorbance (OD250 twofold greater), but humic substances (OD440) remained low. Both C sources resulted in 40% declines in oxygen saturation and two- to threefold increases in dissolved inorganic and total P but no effects on NH4+ or NO3-. Bacterial growth was stimulated by 20% in systems receiving macrophyte C but declined by 50% in systems with terrestrial C. Initially, controls had >60% greater chlorophyll a concentrations than C-amended systems, but mesocosms with macrophyte C exhibited the greatest chlorophyll a concentrations after day 10. Autotrophic nanoflagellates <20 µm (Chrysochromulina parva, Ochromonas) increased in controls but were inhibited in C-amended systems. Cyanobacteria (Coelosphaerium naeglianum, Anabaena, Dactylococcopsis acicularis) numbers increased in mesocosms with macrophyte C; densities of most algal taxa declined in terrestrial-supplemented systems, except certain flagellates (Synura, Cryptomonas, Ceratium hirundinella), which were enhanced. Abundances of heterotrophic nanoflagellates, rotifers, Daphnia pulicaria, and copepod nauplii were stimulated by macrophyte C; only the copepod Mesocyclops edax increased following addition of terrestrial C.
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