Effects of bottom-up and top-down interactions on the productivity of Iyieke Lake, Afikpo North, Ebonyi State, south-east Nigeria

2020 ◽  
Vol 17 ◽  
pp. 6-12
Author(s):  
G.N. Nwonumara ◽  
O.O. Idumah

The bottom-up and top-down interactions of the abiotic and biotic components of Iyieke Lake were studied for eleven months covering a pre-flood, flood and post-flood periods. During the study, some water quality parameters were measured while plankton samples were collected for identification in the laboratory using standard method. The results of the water quality parameters measured showed that water temperature was highest (35.00R”C) in February. pH (7.10) and transparency (0.98 m) were highest in August. Highest TDS (28.0 mg/L) and conductivity (56.00 μS/cm) were recorded in March (pre-flood period) while dissolved oxygen level was lowest (4.00 mg/L) in the pre-flood period (February and March). Nitrate (0.18 mg/L) was highest in August (flood period) and phosphate (0.25 mg/L) at the two extreme periods (pre-flood and post flood). The depth of the lake was highest (3.2 m) in August which was the period of inundation. The phytoplankton (Bacillariophyta, Chlorophyta, Cyanobacteria) and zooplankton (Rotifera, Cladocera, Copepoda) of the lake were made of three divisions and taxa each, respectively. Bacillariophyta dominated among the phytoplankton while Rotifera was the most abundant among the zooplankton. The study revealed that nutrients and zooplankton grazing were the major factors that affected phytoplankton abundance and biomass during the study. Keywords: Flood; phytoplankton; Iyieke; water quality; zooplankton

2015 ◽  
Vol 21 ◽  
pp. 27-34 ◽  
Author(s):  
Md Lifat Rahi ◽  
Sarower E Mahfuj ◽  
Sk Shahinur Islam ◽  
S Saiful Islam ◽  
Wasim Sabbir

Context: Phytoplanktonic community structure in an aquatic body embodies the energy transfer through this phase and indicates the tropic status. Objectives: The present study was conducted to assess the phytoplankton abundance and species composition of Mouri River, Khulna, Bangladesh. Materials and Methods: Water samples were collected from six different stations once in a week for a period of 6 months (February- July) 2010. Results: In total 48 different species of 23 genus and 4 families were identified. Phytoplankton abundance varied from 805 to 1788 individuals/L in different stations. The highest abundance was observed for the family chlorophyceae that constituted 27-50.56% of the total phytoplankton biomass throughout the river. Highest number of phytoplankton species (22) was also recorded for the family chlorophyceae. The most diverse genus was Navicula (6). Some aspects of the water quality parameters were measured by regression analysis and significant correlations were also observed between water quality parameters and phytoplankton abundance. Water temperature, pH, DO, Free CO2, alkalinity, hardness, calcium and magnesium showed positive correlations with total phytoplankton abundance where as transparency, TDS, TSS, sulfate phosphate and nitrite showed negative correlations. Conclusion: In most of the cases, phytoplankton abundance and water quality parameters showed greater deviation from the optimum level. However, the results of the present experiment confirmed the polluted water of the river. DOI: http://dx.doi.org/10.3329/jbs.v21i0.22516 J. bio-sci. 21: 27-34, 2013


2015 ◽  
Vol 8 (1) ◽  
pp. 85-89
Author(s):  
F Zannat ◽  
MA Ali ◽  
MA Sattar

A study was conducted to evaluate the water quality parameters of pond water at Mymensingh Urban region. The water samples were collected from 30 ponds located at Mymensingh Urban Region during August to October 2010. The chemical analyses of water samples included pH, EC, Na, K, Ca, S, Mn and As were done by standard methods. The chemical properties in pond water were found pH 6.68 to 7.14, EC 227 to 700 ?Scm-1, Na 15.57 to 36.00 ppm, K 3.83 to 16.16 ppm, Ca 2.01 to 7.29 ppm, S 1.61 to 4.67 ppm, Mn 0.33 to 0.684 ppm and As 0.0011 to 0.0059 ppm. The pH values of water samples revealed that water samples were acidic to slightly alkaline in nature. The EC value revealed that water samples were medium salinity except one sample and also good for irrigation. According to drinking water standard Mn toxicity was detected in pond water. Considering Na, Ca and S ions pond water was safe for irrigation and aquaculture. In case of K ion, all the samples were suitable for irrigation but unsuitable for aquaculture.J. Environ. Sci. & Natural Resources, 8(1): 85-89 2015


2018 ◽  
Vol 69 (8) ◽  
pp. 2045-2049
Author(s):  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Ion Onutu

Monitoring of environmental factors allows the achievement of some important objectives regarding water quality, forecasting, warning and intervention. The aim of this paper is to investigate water quality parameters in some potential pollutant sources from northern, southern and east-southern areas of Romania. Surface water quality data for some selected chemical parameters were collected and analyzed at different points from March to May 2017.


1982 ◽  
Vol 14 (4-5) ◽  
pp. 43-58 ◽  
Author(s):  
M Rizet ◽  
J Mouchet

This study was conducted in order to understand the taste and odour problems that occurred in the Seine and the Marne rivers during the severe drought of 1976. Samples were taken every 15 days from several locations in the rivers themselves and from storage reservoirs upstream from Paris. Algae and actinomycetes were identified and counted. Metabolite concentrations were measured. These data were correlated with threshold odor numbers and bacteriological water quality parameters.


Water ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 507 ◽  
Author(s):  
Iván Vizcaíno ◽  
Enrique Carrera ◽  
Margarita Sanromán-Junquera ◽  
Sergio Muñoz-Romero ◽  
José Luis Rojo-Álvarez ◽  
...  

2021 ◽  
Vol 9 (5) ◽  
pp. 474
Author(s):  
René Rodríguez-Grimón ◽  
Nestor Hernando Campos ◽  
Ítalo Braga Castro

Since 2013, there has been an increase (>23%) in naval traffic using maritime routes and ports on the coastal fringe of Santa Marta, Colombia. Of major concern, and described by several studies, is the relationship between maritime traffic and coastal contamination. This study proposed a maritime traffic indicator considering the simultaneous effects of several relevant measurements of water quality parameters to estimate the impact of naval activity. The approach involved developing a model including the number of vessels, hull length, and permanence time in berths. In addition, water quality variables, considering climatic seasons, were used to verify association with maritime traffic and touristic activities. The high concentrations of total coliforms (TC) and dissolved/dispersed petroleum hydrocarbons in chrysene equivalents (DDPH) reported by the International Marina of Santa Marta (SM) were affected by the local anthropic activities, including tourism, naval traffic, and urban wastewater discharges. Moreover, our results suggest the occurrence of multiple chemical impacts within Tayrona National Natural Park (PNNT) affecting conservation goals. The estimation of the maritime traffic indicator proposed in this study may be an easy and more complete tool for future studies evaluating the impact of naval activities on environmental quality.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1547
Author(s):  
Jian Sha ◽  
Xue Li ◽  
Man Zhang ◽  
Zhong-Liang Wang

Accurate real-time water quality prediction is of great significance for local environmental managers to deal with upcoming events and emergencies to develop best management practices. In this study, the performances in real-time water quality forecasting based on different deep learning (DL) models with different input data pre-processing methods were compared. There were three popular DL models concerned, including the convolutional neural network (CNN), long short-term memory neural network (LSTM), and hybrid CNN–LSTM. Two types of input data were applied, including the original one-dimensional time series and the two-dimensional grey image based on the complete ensemble empirical mode decomposition algorithm with adaptive noise (CEEMDAN) decomposition. Each type of input data was used in each DL model to forecast the real-time monitoring water quality parameters of dissolved oxygen (DO) and total nitrogen (TN). The results showed that (1) the performances of CNN–LSTM were superior to the standalone model CNN and LSTM; (2) the models used CEEMDAN-based input data performed much better than the models used the original input data, while the improvements for non-periodic parameter TN were much greater than that for periodic parameter DO; and (3) the model accuracies gradually decreased with the increase of prediction steps, while the original input data decayed faster than the CEEMDAN-based input data and the non-periodic parameter TN decayed faster than the periodic parameter DO. Overall, the input data preprocessed by the CEEMDAN method could effectively improve the forecasting performances of deep learning models, and this improvement was especially significant for non-periodic parameters of TN.


Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1682
Author(s):  
Yoonja Kang ◽  
Yeongji Oh

The interactive roles of zooplankton grazing (top-down) and nutrient (bottom-up) processes on phytoplankton distribution in a temperate estuary were investigated via dilution and nutrient addition experiments. The responses of size-fractionated phytoplankton and major phytoplankton groups, as determined by flow cytometry, were examined in association with zooplankton grazing and nutrient availability. The summer bloom was attributed to nanoplankton, and microplankton was largely responsible for the winter bloom, whereas the picoplankton biomass was relatively consistent throughout the sampling periods, except for the fall. The nutrient addition experiments illustrated that nanoplankton responded more quickly to phosphate than the other groups in the summer, whereas microplankton had a faster response to most nutrients in the winter. The dilution experiments ascribed that the grazing mortality rates of eukaryotes were low compared to those of the other groups, whereas autotrophic cyanobacteria were more palatable to zooplankton than cryptophytes and eukaryotes. Our experimental results indicate that efficient escape from zooplankton grazing and fast response to nutrient availability synergistically caused the microplankton to bloom in the winter, whereas the bottom-up process (i.e., the phosphate effect) largely governed the nanoplankton bloom in the summer.


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