Effects of Diversity, Coverage and Biomass of Submerged Macrophytes on Nutrient Concentrations, Water Clarity and Phytoplankton Biomass in Two Restored Shallow Lakes

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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Management Strategies for Eutrophication and Macrophyte Growth in Two Urban Lakes in Saint-Bruno, Quebec

Water Quality Research Journal ◽

10.2166/wqrj.1992.026 ◽

1992 ◽

Vol 27 (2) ◽

pp. 383-402

Author(s):

Roland Leduc ◽

M. Robin Anderson

Keyword(s):

Water Quality ◽

Shallow Lakes ◽

Myriophyllum Spicatum ◽

Management Strategies ◽

Quality Parameters ◽

Source Control ◽

Partial Control ◽

Technical Feasibility ◽

Sampling Locations ◽

Macrophyte Growth

Abstract Two small, shallow lakes (Ruisseau and Village lakes), located in Saint-Bruno near Montreal (Québec), were studied in 1987 to determine the extent of, and to propose alleviation solutions to eutrophication and to macrophyte growth. Flows and various water quality parameters were monitored in the influents and in the lakes, and macrophytes were harvested at four different locations in Village Lake. Both lakes were found to be highly eutrophic. The dominant plant specie was found to be Myriophyllum spicatum. Biomass densities were high with values of 206, 212 and 395 g/m2 at three of these sampling locations. A number of alternatives which could mitigate eutrophication and the presence of macrophytes are discussed in terms of technical feasibility and cost. Source control of nutrients, along with citizens involvement, and partial control of macrophytes were recommended management strategies.

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Epiphytic diatoms and water quality in shallow lakes: the neutral substrate hypothesis revisited

Marine and Freshwater Research ◽

10.1071/mf10018 ◽

2010 ◽

Vol 61 (12) ◽

pp. 1457 ◽

Cited By ~ 17

Author(s):

Cristina Cejudo-Figueiras ◽

Irene Álvarez-Blanco ◽

Eloy Bécares ◽

Saúl Blanco

Keyword(s):

Water Quality ◽

Quality Assessment ◽

Shallow Lakes ◽

Water Quality Assessment ◽

Trophic Levels ◽

Nutrient Concentrations ◽

North West ◽

Epiphytic Diatoms ◽

Diatom Indices ◽

Diatom Communities

For bioassessment of freshwaters, diatom indices have been mainly used in streams although their applicability in shallow lakes has been demonstrated in several studies. However, the influence of sampling substrata on periphytic diatom communities and on the ecological quality inferred from them has been paid little attention. In this paper, we test the ‘neutral substrate hypothesis’, which predicts no relevant influence of host plant type on their epiphytic community. Nineteen shallow permanent lakes from north-west Spain were studied and classified into three trophic levels. Epiphytic diatom communities growing on three different macrophytes for each trophic level were sampled and analysed. We assess: (1) which of the most common diatom indices provides a reliable water quality assessment, (2) how different plant substrata influence the diatom communities growing on them and (3) how these differences affect water quality assessment. Similarity tests showed significant differences in the composition of diatom assemblages among nutrient concentrations and host macrophytes. In contrast, ANOVA results for selected diatom-based metrics showed significant differences among trophic levels but not between different plant substrata. This supports the use of epiphytic diatoms as biological indicators for shallow lakes irrespective of the dominant macrophyte.

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Predicting Lake Eutrophication Responses to Multiple Scenarios of Lake Restoration: A Three-Dimensional Modeling Approach

Water ◽

10.3390/w10080994 ◽

2018 ◽

Vol 10 (8) ◽

pp. 994 ◽

Cited By ~ 9

Author(s):

Yanping Wang ◽

Weiping Hu ◽

Zhaoliang Peng ◽

Ye Zeng ◽

Karsten Rinke

Keyword(s):

Water Quality ◽

Drinking Water ◽

Three Dimensional ◽

Water Transfer ◽

Nutrient Concentrations ◽

Observation Data ◽

Nutrient Reduction ◽

Effective Measure ◽

The Impact ◽

Restoration Measures

To improve the water quality and alleviate the eutrophication of Lake Yangchenghu, the third largest freshwater body within the Lake Taihu basin in China and an important source of drinking water, nutrient reduction strategies should be urgently addressed by decision makers, since virtually no improvement of water quality has taken place since the mid-1990s. Due to the lack of sufficient observation data and simulation results, a vertically compressed three-dimensional numerical model, the EcoTaihu model, was used to study the impact of three restoration measures on the water quality—namely, total nitrogen (TN), total phosphorus (TP) and biomass of phytoplankton (BP)—of Lake Yangchenghu: (i) total nutrient reduction, (ii) intensification of flushing by water transfer, and (iii) spatial adjustment of inflow channels. In particular, the spatial effects of the three restoration measures on the water quality were investigated. The results showed that the EcoTaihu model is applicable to other shallow lakes in China. The water quality responses to the different restoration scenarios showed significant spatio-temporal differences. The reduction of nutrient loads from inflows appeared to be the most effective measure for controlling the eutrophication and algal blooms in Lake Yangchenghu. The effectiveness of water transfer on the improvement of water quality for TN and TP was more influenced by the differences of nutrient concentrations between the transferred water and lake water, rather than flow rate, since no proportionate increase of improvement was observable in the case of larger transferred rates (60 m3 s−1). The spatial narrowing of inflowing rivers in the southwestern lake could preferentially improve the water quality in the southern bay of the western lake, but would also result in a deterioration trend of water quality in the total lake and drinking water abstraction areas.

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Effects of Sediments Phosphorus Inactivation on the Life Strategies of Myriophyllum spicatum: Implications for Lake Restoration

Water ◽

10.3390/w13152112 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2112

Author(s):

Zhenmei Lin ◽

Chen Zhong ◽

Guolong Yu ◽

Yishu Fu ◽

Baohua Guan ◽

...

Keyword(s):

Shallow Lakes ◽

Root Biomass ◽

Submerged Macrophytes ◽

Myriophyllum Spicatum ◽

Morphological Characteristics ◽

Shoot Biomass ◽

Lake Ecosystem ◽

Total Biomass ◽

Life Strategies ◽

Eutrophic Lakes

Eutrophication often results in the loss of submerged vegetation in shallow lakes and turns the lake to be a turbid state. Recovery of submerged macrophytes is the key in the restoration of shallow eutrophic lakes to create a clear water state. However, internal loading control was considered as the critical process for the recovery of submerged macrophytes in shallow lakes after the external nutrient reduction. Phoslock® (Lanthanum modified bentonite) is a useful passivation material in controlling the internal loadings (release of phosphorus from the sediments), which was applied to restore the eutrophic lakes. However, the effects of Phoslock® on the growth and life strategies of submerged macrophytes are less focused so far. In the present study, we studied the responses in the growth and morphological characteristics of Myriophyllum spicatum to the addition of Phoslock® to the sediments. Our results showed that the addition of Phoslock® significantly decreased the contents of bioavailable forms of phosphorus in the sediments, such as redox-sensitive phosphorus bound to Fe and Mn compounds (BD–P), phosphorus bound to aluminum (Al–P) and organic phosphorus (Org–P). However, the concentration of the non-bioavailable forms of phosphorus in the sediments, such as calcium bound phosphorus (Ca–P), increased significantly in the Phoslock® treatments compared with the controls. At the end of the experiments, the total biomass, aboveground biomass and relative growth rate (RGR) of M. spicatum decreased significantly in the Phoslock® mesocosms compared with the controls. In contrast, the wet root biomass, root–shoot biomass ratio, root numbers and root length of M. spicatum were significantly higher in the Phoslock® treatments than that in the controls. Our results indicated that the growth of M. spicatum was suppressed by the addition of Phoslock®, and thus the biomass was decreased; however, the increase of root biomass might be beneficial to the inhibition of phosphorus release and resuspension of sediments and to the restoration of the lake ecosystem.

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A small omnivore fish (Acheilognathus macropterus) reduces both growth and biomass of submerged macrophytes: implications for shallow lake restoration

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2020028 ◽

2020 ◽

pp. 34

Author(s):

Jinlei Yu ◽

Manli Xia ◽

Wei Zhen ◽

Hu He ◽

Ruijie Shen ◽

...

Keyword(s):

Fish Assemblages ◽

Submerged Macrophytes ◽

Myriophyllum Spicatum ◽

Nutrient Concentrations ◽

Ceratophyllum Demersum ◽

Total Biomass ◽

Relative Growth ◽

Macrophyte Community ◽

Macrophyte Species ◽

Significant Research

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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Increased Nitrogen Loading Boosts Summer Phytoplankton Growth by Alterations in Resource and Zooplankton Control: A Mesocosm Study

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.772314 ◽

2021 ◽

Vol 9 ◽

Author(s):

Hu He ◽

Kunquan Chen ◽

Yingxun Du ◽

Kuanyi Li ◽

Zhengwen Liu ◽

...

Keyword(s):

Shallow Lakes ◽

Phytoplankton Biomass ◽

Nitrogen Loading ◽

Phytoplankton Growth ◽

N Addition ◽

Eutrophic Lakes ◽

Benthivorous Fish ◽

Subtropical Lakes ◽

Strategic Approach ◽

N Loading

The effectiveness of controlling nitrogen (N) to manage eutrophication of aquatic ecosystems remains debated. To understand the mechanisms behind phytoplankton growth in shallow lakes (resource and grazing effects) under contrasting N loading scenarios, we conducted a 70-days mesocosm experiment in summer. The mesocosms contain natural plankton communities deriving from a 10-cm layer of lake sediment and 450 L of lake water. We also added two juvenile crucian carp (Carassius carassius) in each mesocosm to simulate presence of the prevailing omni-benthivorous fish in subtropical lakes. Our results showed that N addition increased not only water N levels but also total phosphorus (TP) concentrations, which together elevated the phytoplankton biomass and caused strong dominance of cyanobacteria. Addition of N significantly lowered the herbivorous zooplankton to phytoplankton biomass ratio and promoted the phytoplankton yield per nutrient (Chl-a: TP or Chl-a: TN ratio), indicating that summer N addition likely also favored phytoplankton growth through reduced grazing by zooplankton. Accordingly, our study indicates that summer N loading may boost eutrophication via both changes in resource and grazing control in shallow lakes. Thus, alleviation of eutrophication in shallow eutrophic lakes requires a strategic approach to control both nutrients (N and P) appropriately.

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Omnivorous shrimp Neocaridina denticulata sinensis enhances the growth of submerged macrophyte Vallisneria denseserrulata

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2019025 ◽

2019 ◽

pp. 32 ◽

Cited By ~ 1

Author(s):

Jialiang Ye ◽

Yali Tang ◽

Xiufeng Zhang ◽

Ping Zhong ◽

Zhengwen Liu

Keyword(s):

Growth Rate ◽

Shallow Lakes ◽

Phytoplankton Biomass ◽

Leaf Surface ◽

Submerged Macrophytes ◽

Submerged Macrophyte ◽

Lake Eutrophication ◽

Shading Effects ◽

Neocaridina Denticulata ◽

Eutrophic Shallow Lakes

Lake eutrophication often causes declines and even losses of submerged macrophytes through the shading effects of increased periphyton and phytoplankton. The Chinese swamp shrimp Neocaridina denticulata sinensis Kemp (Decapoda, Atyidae) is a common omnivore in Chinese lakes, where its presence may impact both periphyton and phytoplankton, with previously unstudied consequences for submerged macrophytes. Here, using a mesocosm experiment, we studied the effect of N. d. sinensis on periphyton, phytoplankton and the submerged macrophyte Vallisneria denseserrulata. Results showed that in the presence of N. d. sinensis, the biomass of periphyton on the leaves of V. denseserrulata was significantly reduced, and that growth rate of V. denseserrulata increased. The presence of N. d. sinensis also significantly increased the total phosphorus concentrations in the water column and phytoplankton biomass (chlorophyll-a). The enhanced growth of V. denseserrulata is likely to be linked to improved light harvesting due to the reduced periphyton attached to their leaf surface. The results suggest that stocking with Chinese swamp shrimps may enhance the development of macrophytes in eutrophic shallow lakes.

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Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

Water Science & Technology ◽

10.2166/wst.1990.0021 ◽

1990 ◽

Vol 22 (5) ◽

pp. 137-144 ◽

Cited By ~ 3

Author(s):

M. T. Dokulil ◽

G. A. Janauer

Keyword(s):

Water Quality ◽

Control System ◽

Trophic Status ◽

High Water ◽

Nutrient Concentrations ◽

Nutrient Input ◽

Water Control ◽

Trophic Conditions ◽

River Danube ◽

High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

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Impact of Catchment Urbanisation on Lake Macquarie (Australia)

Water Science & Technology ◽

10.2166/wst.1989.0051 ◽

1989 ◽

Vol 21 (2) ◽

pp. 205-210 ◽

Cited By ~ 1

Author(s):

B. L. Simmons ◽

S. L. Trengove

Keyword(s):

Nutrient Enrichment ◽

Benthic Algae ◽

Water Clarity ◽

Nutrient Concentrations ◽

Lake Area ◽

Seagrass Beds ◽

Coastal Lake ◽

Aesthetic Quality ◽

Wastewater Disposal ◽

Coastal Lakes

Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge. The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased. Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.

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Long-Term (15 Years) Results of NPS Controls in an Agricultural Watershed upon a Receiving Lake's Water Quality

Water Science & Technology ◽

10.2166/wst.1993.0447 ◽

1993 ◽

Vol 28 (3-5) ◽

pp. 441-449 ◽

Cited By ~ 8

Author(s):

Paul J. Garrison ◽

Timothy R. Asplund

Keyword(s):

Water Quality ◽

Structural Changes ◽

Soil Phosphorus ◽

Water Clarity ◽

Management Control ◽

Agricultural Watershed ◽

Control Measures ◽

Phosphorus Loading ◽

Phosphorus Concentration ◽

White Clay

Nonpoint source controls were installed in a 1215 ha agricultural watershed in northeastern Wisconsin in the late 1970. Changes were made in handling of animal wastes and cropping practices to reduce runoff of sediment and nutrients. Modelling results predicted a reduction in phosphorus runoff of 30 percent. The water quality of White Clay Lake has worsened since the installation of NPS controls. The lake's phosphorus concentration has increased from a mean of 29 µg L−1 in the late 1970s to 44 µg L−1 in recent years. Water clarity has declined from 2.7 to 2.1 m and the mean summer chlorophyll levels have increased from 9 to 13 µg L−1 with peak values exceeding 40 µg L−1. Increased phosphorus loading is not the result of elevated precipitation but instead the failure of the control measures to sufficiently reduce P loading. Most of the effort was placed on structural changes while most of the P loading comes from cropland runoff. Further, soil phosphorus concentrations have increased because of artificial fertilizers and manure spreading. The White Clay Lake experience is discouraging since the majority of the polluters in this watershed utilized some NPS control practices, including 76 percent of the farms which installed waste management control facilities.

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