scholarly journals THE MODERN STATUS OF THE VELIKAYA RIVER DELTA ON THE STATE OF PRIMARY PRODUCERS

Author(s):  
Tatiana Drozdenko ◽  
Sergei Mikhalap ◽  
Kristina Mikhaylova ◽  
Anna Chernova

Primary producers are an integral part of freshwater ecosystems. Phytoplankton forms the basis of the trophic pyramid, participates in the formation of water quality and acts as a sensitive indicator of the state of the reservoir. The ability of macrophytes to accumulate mineral and organic substances makes them active participants in the self-purification of natural waters. Higher aquatic plants are characterized by conservatism to short-term changes in the environment, but changes in vegetation over the years may indicate anthropogenic transformation of ecosystems. The contribution to maintaining the stability of the functioning and biodiversity of the ecosystem makes phytoplankton and macrophytes compulsory research objects aimed at studying the state of water bodies. The aim of the work was the study of primary producers as bioindicators of the ecological status of the Velikaya river delta in the summer of 2018. As a result, 127 phytoplankton taxa from 8 phylums were found: Chlorophyta, Bacillariophyta, Cyanobacteria, Euglenophyta, Chrysophyta, Dinophyta, Cryptophyta, Charophyta. The species richness was dominated by the Chlorophyta (42.5%), Bacillariophyta (25.2%), Cyanobacteria (11.1%). According to the ecological and geographical analysis of the delta algaflora, cosmopolitan, freshwater, planktonic forms of microalgae dominate, preferring neutral and weakly alkaline waters. Water quality assessment revealed the beta-mesosaprobic nature of the waters, which indicates moderate pollution of the water area. In the composition of macrophytes, 43 species from 3 phylums were identified: Magnoliophyta, Equisetophyta, Chlorophyta. By species composition, angiosperms dominated (95.3%), of which 46.3% were dicotyledons and 53.7% - monocotyledons. Hygrophytes (34.9%) and hydrophytes (32.6%) prevailed in terms of ecological structure. The leading role in the overgrowing of the delta belonged to high-grass helophytes and rooting hydrophytes with leaves floating on the water. A total of 37 saprobiont flora were found. The total index of saprobity was 277 points.

Author(s):  
Tatiana Drozdenko ◽  
Sergei Mikhalap ◽  
Larisa Nikolskaya ◽  
Anna Chernova

The basis of the existence of freshwater ecosystems is phytoplankton, which produces most of the primary biological production, participates in repair processes and provides a wide range of ecosystem services. The short life cycle and high speed metabolism of microalgae make them ideal objects for ecological monitoring. The aim of the present study is to research the ecological state of the Velikaya river delta based on the species composition of phytoplankton community and some hydrochemical parameters. The sample collection for phytoplankton study and physicochemical measurements was carried out in summer 2016 at five stations representing different ecological locations of the Velikaya river delta. One hundred sixty five species taxa of microalgae belonging to 8 phylums were identified during the research: Bacillariophyta (37%), Chlorophyta (33.9%), Cyanophyta/Cyanobacteria (9.7%), Chrysophyta (6.1%), Euglenophyta (6.1%), Cryptophyta (3%), Dinophyta (3%), Xanthophyta (1.2%). The values of Shannon index indicate the average complexity of the microalgae communities structure. Values of Margalef index characterize the Velikaya river delta as an area of high species richness. Compared to the previous studies, a significant increase in the level of information diversity is observed, indicating an increase in the number of possible flows of substance and energy in the ecosystem. Dynamics of biogen substances in the water shows a slight increase of their concentrations. Ecological and geographical analysis proves that absolute dominance of cosmopolitan freshwater forms is typical for the algoflora of the Velikaya river delta. In relation to the pH-reaction inhabitants of neutral and slightly alkaline water dominate. Pantle–Buck saprobity index is applied for water quality assessment, which shows beta-mesosaprobic water quality in the ecosystem. Thus, the water of the Velikaya river delta could be referred to the category of moderately polluted water (class II of water quality). This is confirmed by the data of hydrochemical analysis.


2019 ◽  
Vol 11 (6) ◽  
pp. 1668 ◽  
Author(s):  
Daissy Milena Díaz-Casallas ◽  
Mario Fernando Castro-Fernández ◽  
Elvira Bocos ◽  
Carlos Enrique Montenegro-Marin ◽  
Rubén González Crespo

This article provides a deep analysis of the water quality at the upper basin of the Bogota River (Colombia) between 2008 and 2017. The Water Quality Index has been the indicator employed to determine the ecological status of the river. This index was chosen in order to normalize the analysis, given that it is commonly used by the Institute of Hydrology, Meteorology and Environmental Studies, a government agency of the Ministry of Environment and Sustainable Development of Colombia, to determine the state of surface effluents. The results obtained were organized in a double-entry matrix in order to relate the variables of the sample period and the sampling station. The research revealed an insufficient quality of water, demonstrating that the high stretch of the Bogota River basin has, in general, regular or acceptable water quality, while only five stations showed an acceptable status. Surprisingly, the stations located close to the wastewater treatment plants of the municipalities of Choconta, Suesca, Gachancipa, and Tocancipa, as well as Rio Negro, have a poor water quality, discharging a high load of contaminants into the river. Although great efforts have been made by Colombian authorities to restore the critical state of the majority of their aquatic ecosystems, recent implementation of policies and instruments have not shown significant achievements yet. For this reason, this study aims to present a powerful decision-tool for the monitoring and evaluation of correction measures implemented on this river basin. The data used in this research were provided by the Regional Autonomous Corporation of Cundinamarca.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Leo Posthuma ◽  
Michiel C. Zijp ◽  
Dick De Zwart ◽  
Dik Van de Meent ◽  
Lidija Globevnik ◽  
...  

Abstract Aquatic ecosystems are affected by man-made pressures, often causing combined impacts. The analysis of the impacts of chemical pollution is however commonly separate from that of other pressures and their impacts. This evolved from differences in the data available for applied ecology vis-à-vis applied ecotoxicology, which are field gradients and laboratory toxicity tests, respectively. With this study, we demonstrate that the current approach of chemical impact assessment, consisting of comparing measured concentrations to protective environmental quality standards for individual chemicals, is not optimal. In reply, and preparing for a method that would enable the comprehensive assessment and management of water quality pressures, we evaluate various quantitative chemical pollution pressure metrics for mixtures of chemicals in a case study with 24 priority substances of Europe-wide concern. We demonstrate why current methods are sub-optimal for water quality management prioritization and that chemical pollution currently imposes limitations to the ecological status of European surface waters. We discuss why management efforts may currently fail to restore a good ecological status, given that to date only 0.2% of the compounds in trade are considered in European water quality assessment and management.


Author(s):  

The object of the study were three different in their hydrological characteristics, as well as the degree of anthropogenic load on them (in the form of sewage from the adjacent territory), the area of the water area of the Volga reaches of the Kuibyshev Reservoir, where there are deposits of nonmetallic building materials. Studies were conducted during the vegetation period 2014-2015. They included physical/chemical studies and studies of the state of zooplankton. Total 311 samples of zooplankton were collected and processed. During the study, 30 species of zooplankton organisms were recorded: 7 species of Rotifera, 7 species of Copepoda and 16 species of Cladocera. The richest in terms of the quantitative diversity of species was No. 3 site. Prevalent in terms of number and biomass of organisms – site number 1. Quantitative indicators of zooplankton were observed in 2015 compared to 2014. This is explained by the fact that 2014 was warmer than 2015. The oxygen regime of 2014 was also better than that of 2015. The turbidity of water in 2014 was below the turbidity of water in 2015, the quality of water in the second year of research deteriorated compared to the first in a number of indicators, such as COD, compounds copper, zinc, manganese, oil products. The mid-vegetation indexes of saprobity for the indicated observation period make it possible to attribute these sections of the Volga reach of the Kuibyshev reservoir to the β-mesosaprobic zone, which corresponds to the third class of water quality - moderately polluted water. Proceeding from the obtained values of the Shannon and Pielu indices, the zooplankton of the studied sections of the Volga reaches of the Kuibyshev reservoir has a rather low species richness with a rigid type of dominance, which characterizes it as mesotrophic. The ratio of groups of organisms and the dominance of individual species indicates a deterioration in water quality over a two-year period of research, which is confirmed by the research conducted by the Federal State Unitary Enterprise «UGMS RT».


Author(s):  
Dmitrii B. Denisov ◽  
Anna L. Kosova

Large-scale diatom communities and diatom complexes of lake sediments researches in the Euro-Arctic region have been carried out. The high efficiency of bioindication of water quality and the state of ecosystems based on diatoms have been shown for the water quality assessment and anthropogenic loads rationing on water resources of high latitudes. Diatom assemblages from lake sediments of different types of aquatic ecosystems reflect the present-day warming of the Arctic climate and the effects of aerotechnogenic pollution. Diatom assemblages of surface (0–1 cm) layers of lake sediments could well serve for the integral assessment of the state of ecosystems and water quality. Diatoms diversity of the Green Belt of Fennoscandia in the territory of the Murmansk region has been investigated.


2020 ◽  
Vol 71 (1) ◽  
pp. 384-389
Author(s):  
Delia Nica-Badea ◽  
Simona Brandibur

Water quality criteria are all physicochemical and biological indicators that characterize a body of water. The current study aims at investigating the quality of two natural waters in the Gorj County sub-mountainous area (�u�i�a, Vaidei and Runc, capture Runc) used as drinking water sources of Targu-Jiu. Sampling and determinations use spectrophotometric, gravimetric, volumetric or electrometric techniques in accordance with standard methods (SR ISO and / or SR EN) for a series of physicochemical indicators analyzed between January - December 2017: thermal and acidification, oxygen regime, nutrients, salinity, relevant pollutants. Experimental values, annual averages related to the quality standards for potable water, ecological status and classification of water bodies, place the water of the two rivers in the drinking water category A1 and the first class of ecological quality. The Water Quality Index (WQI) for 9 selected parameters highlighted a sensitively close overall level of the water of the two rivers Susita (88) and Runc (85.2), the good quality category (7o-9o), reported to national quality standards for surface water which can be used for delivery as drinking water.The study of indicators of the two rivers in relation to national rules aligned with the European water requirements and research shows a high qualitative status corresponding to community uses.


2015 ◽  
Vol 15 (4) ◽  
pp. 155-164 ◽  
Author(s):  
Ewa A. Dembowska ◽  
Patrycja L. Pul

Abstract The routine evaluation of water quality is limited to lakes with the largest area. In Poland, only lakes with an area exceeding 50 hectares are monitored by the State Environmental Monitoring System. For many local communities, however, small lakes are more important. This applies mainly to areas with a small number of lakes, where even the smallest lakes are used for various purposes. This paper presents the results of phytoplankton analysis in a small and shallow lake used for recreation. The study was conducted at three sites located in different parts of the lake. A total of 122 algae taxa were identified in the phytoplankton, mainly diatoms and green algae. The most constant taxa in the lake were: Stephanodiscus hantzschii, Desmodesmus communis, Pediastrum tetras and Crucigenia tetrapedia. The average phytoplankton biomass was 37 mg l−1. The maximum biomass, almost 140 mg dm−3, was recorded in late July at the site located near the beach. At that time, there was a massive cyanobacterial bloom composed of Microcystis wesenbergii and Aphanizomenon issatschenkoi. Based on these studies, the lake should be classified as hypertrophic with bad ecological status. This lake should not be used for recreational purposes in the current state.


2019 ◽  
Vol 8 (2) ◽  
pp. 75-80
Author(s):  
Elena Aleksandrovna Shornikova

The following paper deals with a methodical approach and experience of water quality complex index ( Iwq ) use for the evaluation of ecological status of surface water bodies by results of rivers monitoring within the Middle Ob basin during 2002-2018. This index allows to use such primary information as results of water chemistry analyses, parameters of structure of microbial community and other available data obtained for each sample site on various water bodies within the basin. The main evaluation criterion for calculating this index is a degree of a deviation of each controlled indicator from average value of this indicator for all explored water area within the basin. Water bodies (or their sites) can be classified to 5 various classes of water quality using the calculated values of the index. Such a methodical approach allows to carry out comparative estimation of an ecological condition of water bodies and their sites within the area, to map the obtained data, to analyze possible reasons of deterioration of water ecosystem state, to manage decisions on their restoration. The paper presents the results of the water quality complex index use for rivers within the Middle Ob basin, calculated on the base of indicators of the chemical composition of water and number of bacteria of various ecological and trophic groups in the structure of microbial community.


2021 ◽  
Author(s):  
Sergey V. Kholodkevich ◽  
Maxim K. Motruk ◽  
Vasiliy A. Lyubimtsev ◽  
Olga N. Susloparova

The objects of bioindication of the ecological state were 3 channels of the Volga Delta, located both directly in Astrakhan and in the Astrakhan region. The aim of the work was to conduct a comparative bioelectronic diagnosis of the ecological state of the selected channels with different local anthropogenic loads, both by type and size, based on assessments of the functional state (health) of the bivalve mollusks Anodonta anatina living in them, estimated on the basis of an analysis of their cardiorhythm, measured using an original fiber-optic bioelectronic system. It was found that shellfish selected from different water areas, after 1hour functional load, restore the original heart rate for different times, but in the range from 117 to 166 minutes, which is typical for shellfish living in significantly polluted reservoirs of the same ecological status - "Bad". This characteristic of the water areas completely coincides with the characteristic of the ecological state of the channels of the Volga River Delta specified in the State Report "On the state and on Environmental Protection of the Russian Federation in 2017". The authors proposed and justified the possibility of using the water area of the Gandurino River as a conditional reference for the Volga Delta region. In this case, according to the value of the environmental quality coefficient EQR, the channels of the Urban Branch and the Small Channel can be attributed to the regional environmental status - "Good".


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