scholarly journals Seasonal dynamics of Zooplankton functional groups in relation to environmental variables in Xiquanyan Reservoir, Northeast China

Author(s):  
Patteson Chula Mwagona ◽  
Ma Chengxue ◽  
Yu Hongxian

In this study, the concept of functional feeding groups was used to classify and model the seasonal variation of zooplankton functional groups in relation to environmental variables. A total of 48 zooplankton species were observed in the reservoir and grouped into 8 functional groups. Both environmental variable and the biomass of zooplankton functional groups vary spatially and seasonally. Water temperature, water transparency, total nitrogen and nitrates were significantly higher in summer, while chlorophyll-a and ammonium were higher in autumn and spring, respectively. Biomass of zooplankton was significantly higher in summer (245.81 μg/L), followed by autumn (196.54 μg/L) and spring (54.25 μg/L). Group RF (rotifer filter feeders) dominated in spring, accounting for 80% of the total biomass. In summer and autumn, group RC (rotifer carnivore) and SCF (small copepods and cladocerans filter feeders) were the dominant, respectively. Total nitrogen, total phosphorus, ammonium, chlorophyll-a and water transparency were the major factor influencing zooplankton community. Group RF was positively influenced by ammonium and total phosphorus, while RC, SCF and MCF (middle copepods and cladocerans filter feeders) were positively correlated with chlorophyll-a. Top-down control of phytoplankton by groups RC, SCF and MCF in Xiquanyan reservoir is not strong enough to produce negative effect. Increase in predator size biomass did not strengthen top-down control on prey. It is quite clear that the zooplankton function groups of Xiquanyan reservoir followed a predictable seasonal pattern. This therefore highlights the significance of environmental variables in structuring plankton composition in the reservoir.

2014 ◽  
Vol 955-959 ◽  
pp. 1899-1902
Author(s):  
Su Chen ◽  
Lei Chao ◽  
Ning Chen ◽  
Lin Shan Wang ◽  
Xin Liu ◽  
...  

In this experiment, water hyacinth presents a good purification effect in five kinds of eutrophic waters with initial total nitrogen (TN) and total phosphorus (TP) concentrations in between 8.34~20.45 mg/L and 0.78~1.51 mg/L. After two weeks of purification, TN and TP concentrations of eutrophic waters are reduced to 1.78~5.68 mg/L and 0.25~0.312 mg/L, and TN and TP removal rates are 72.22~78.65% and 67.95~79.34%. Water hyacinth’s TN removal rate decreases as TN initial concentration increases; TP removal rate increases as TP initial concentration increases. Water hyacinth’s average total biomass in eutrophic water has increased by 0.944~1.084 kg/m2, and the average bio-dry-weight has increased by 0.0470~0.0547 kg/m2. The average total biomass and average bio-dry-weight of water hyacinth increase as the eutrophication deepens.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.


Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.


Author(s):  
Wojciech Ejankowski ◽  
Tomasz Lenard

<p>The physicochemical parameters of water, the concentration of chlorophyll-<em>a</em> and the submerged aquatic vegetation (SAV) were studied to evaluate the effects of different winter seasons on the biomass of macrophytes in shallow eutrophic lakes. We hypothesised that a lack of ice cover or early ice-out can influence the physicochemical parameters of water and thus change the conditions for the development of phytoplankton and SAV. The studies were conducted in four lakes of the Western Polesie region in mid-eastern Poland after mild winters with early ice-out (MW, 2011 and 2014) and after cold winters with late ice-out (CW, 2010, 2012 and 2013). The concentrations of soluble and total nitrogen, chlorophyll-<em>a</em> and the TN:TP ratio in the lakes were considerably higher, whereas the concentration of soluble and total phosphorus and water transparency were significantly lower after the MW compared with after the CW. No differences were found in water temperature, reaction and electrolytic conductivity. Low water turbidity linked with low concentration of chlorophyll-<em>a</em> after the CW resulted in increased water transparency and the total biomass of the SAV. The negative effect of the MW on the macrophyte species was stronger on more sensitive species (<em>Myriophyllum spicatum</em>,<em> Stratiotes aloides</em>) compared with shade tolerant <em>Ceratophyllum demersum</em>. Our findings show that the ice cover phenology affected by climate warming can change the balance between phytoplankton and benthic vegetation in shallow eutrophic lakes, acting as a shift between clear and turbid water states. We speculate that various responses of macrophyte species to changes in the water quality after two winter seasons (CW and MW) could cause alterations in the vegetation biomass, particularly the expansion of shade tolerance and the decline of light-demanding species after a series of mild winters.</p>


2014 ◽  
Vol 38 (2) ◽  
pp. 656-668 ◽  
Author(s):  
Karina Hacke Ribeiro ◽  
Nerilde Favaretto ◽  
Jeferson Dieckow ◽  
Luiz Cláudio de Paula Souza ◽  
Jean Paolo Gomes Minella ◽  
...  

Water degradation is strongly related to agricultural activity. The aim of this study was to evaluate the influence of land use and some environmental components on surface water quality in the Campestre catchment, located in Colombo, state of Parana, Brazil. Physical and chemical attributes were analyzed (total nitrogen, ammonium, nitrate, total phosphorus, electrical conductivity, pH, temperature, turbidity, total solids, biological oxygen demand, chemical oxygen demand and dissolved oxygen). Monthly samples of the river water were taken over one year at eight monitoring sites, distributed over three sub-basins. Overall, water quality was worse in the sub-basin with a higher percentage of agriculture, and was also affected by a lower percentage of native forest and permanent preservation area, and a larger drainage area. Water quality was also negatively affected by the presence of agriculture in the riparian zone. In the summer season, probably due to higher rainfall and intensive soil use, a higher concentration of total nitrogen and particulate nitrogen was observed, as well as higher electrical conductivity, pH and turbidity. All attributes, except for total phosphorus, were in compliance with Brazilian Conama Resolution Nº 357/2005 for freshwater class 1. However, it should be noted that these results referred to the base flow and did not represent a discharge condition since most of the water samples were not collected at or near the rainfall event.


2017 ◽  
Vol 14 (4) ◽  
pp. 692-706 ◽  
Author(s):  
Baghdad Science Journal

This study focused on benthic algae (epipelic and attached algae on concrete lining stream) in Bani-Hassan stream in Holly Karbala, Iraq. The qualitative and quantitative studies of benthic algae were done by collecting 240 samples from five sites in the study area for the period from December 2012 to November 2013. Also, the environmental variables of the stream were examined in term of temporary and spatial. The results showed that the stream was alkaline, hard, oligohaline and a well aerated. The total nitrogen to the total phosphorus (TN: TP) ratio indicates nitrogen limitation. 129 species of benthic algae belonging to 57 genera were identified. Bacillariophyceae (diatoms) was the predominant taxon (95 species) followed by Chlorophyceae (16 species), Cyanophyceae (14 species), Euglenophyceae (3 species) and Pyrophyceae (one species). Some genera were found throughout the study period: Nitzschia, Navicula, Cymbella, Gomphonema, Surirella, Cocconeis, Aulacoseira, Oscillatoria, Lyngbya, Spirulina, and ? Scenedesmus. Site 3 recorded the highest total number of algae in spring 2013, and the lowest total number was at site 5 in Autumn 2013. The chlorophyll-a concentration did not match the total number of algae.


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