scholarly journals Hydrological/hydrochemical Characteristics of the Upper and Lower Volga Reservoirs during the Low-water Period

2014 ◽  
pp. 14-31
Author(s):  
Keyword(s):  
Organic Matter ◽  
Phosphorus Content ◽  
Biogenic Elements ◽  
Hydrochemical Characteristics ◽  
Allochthonous Organic Matter ◽  
Nitrogen And Phosphorus ◽  
Kuibyshev Reservoir ◽  
Large Cities ◽  
Lower Volga ◽  
Volga Reservoirs

This study of some hydrophysical and hydrochemical (biogenic elements, organic matter) parameters was conducted in the Rybinsk, Gorky, Cheboksary, Volga reservoirs and the Volga-Kama stretch of the Kuibyshev Reservoir during the most tense period of summer low-water. It is shown that during the low-water period differences in nitrogen and phosphorus content between the lacustrine and riverine parts of the Gorky reservoir, observed in spring time, smooth out. The load of allochthonous organic matter decreases and phosphates content increases downstream the cascade of these reservoirs. Water areas downstream large cities can be regarded areas of high environmental risk.

scholarly journals The Pollutants Distribution Types in the Middle and Lower Volga Water and Bottom Sediments

2017 ◽  
Author(s):  
Keyword(s):  
Bottom Sediments ◽  
Petroleum Products ◽  
Water Area ◽  
Content Increase ◽  
Kuibyshev Reservoir ◽  
Volga River ◽  
Metal Compounds ◽  
Lower Volga ◽  
Volga Reservoirs ◽  
Iron Manganese

The outcomes of hydro/chemical and soil 1800 km long surveying of the Volga River from Kazan to Astrakhan have been analyzed. Conjugated analysis of the organic (petroleum products, phenols, and pesticides) and non-organic (metals – Cd, Co, Pb, Ni, Zn, Cr, Mn, Fe, Al) pollutants and their proportion in the Middle and Lower Volga (Kuibyshev, Saratov and Volgograd reservoirs) and unregulated part of downstream water and bottom sediments has been carried out. To test a hypothesis on the system interaction of different types of pollutants content distribution in water and bottom sediments their spatially determined comparative assessment has been applied for the first time. Three main types of the pollutants distribution within the“water-bottom sediments” system have been singled out: depositing, transit, and active/passive self-purification types. The “transit” type of metals distribution is typical for Kuibyshev reservoir. It is characterized by the higher metals concentration in water and the absence of their content increase in bottom sediments. Zones of self-purification from metal compounds have been found in water areas of Saratov and Volgograd reservoirs, while depositing zones are typical for the Volga downstream where metals accumulation in sediments have been found. A considerable portion of pesticides and petroleum products supplied to the Volga reservoirs’ ecosystems is accumulated by bottom sediments. The most part of the Middle and Lower Volga water area is a zone of active selfpurification in terms of phenol compounds. It has been shown that when the Volga environmental conditions is assessed the indicators of copper, nickel, as well as iron, manganese, cadmium and petroleum products in bottom sediments are the most informative.

scholarly journals Features of the long-term dynamics of hydrochemical indicators of the Lower Volga reservoirs and the Ural River (on the example of the Saratov, Volgograd, Iriklinsky reservoirs)

2019 ◽  
Author(s):  
Keyword(s):  
Organic Matter ◽  
Spatial Dynamics ◽  
Geographical Location ◽  
Hydrochemical Regime ◽  
Chemical Indicators ◽  
Method Of Principal Components ◽  
Lower Volga ◽  
Volga Reservoirs ◽  
Flow Through

The article considers the long-term dynamics of organic matter, biogenic and toxic elements in the reservoirs of the Lower Volga (Saratov and Volgograd) and the Ural River (Iriklinskoe), differing in geographical location, morphometric and hydrological characteristics. In the Ural reservoir, in contrast to the Lower Volga reservoirs, lower concentrations of mineral nitrogen, silicon, as well as indicators characterizing allochtonic organic matter, and a higher level of total and easily oxidable organic matter are recorded. There are differences in the seasonal and spatial dynamics of the ingredients. Despite the differences in the hydrochemical regime of the reservoirs under study, the synchronicity of the main indicators characterizing the trophic status of the aquatic ecosystem (total, easily oxidable and allochthonic organic matter, and nitrate nitrogen), as well as the amount of water flow through the corresponding hydroelectric facilities was revealed. Studies of the structure of a multidimensional array of general hydro/chemical indicators by the method of principal components revealed the universality of the processes occurring in reservoir ecosystems, the basis of which is surface runoff and seasonal changes.

scholarly journals SIMULATION SCENARIO OF INTRODUCTION OF FISH WHITEBAIT WITH THE ACCOUNT OF BIOGENIC ELEMENTS DYNAMICS

2017 ◽  
pp. 20-29
Author(s):  
V. V. Michailov ◽  
A. Yu. Perevaryukha
Keyword(s):  
Organic Matter ◽  
Organic Phosphorus ◽  
Juvenile Fish ◽  
Optimal Growth ◽  
Biogenic Elements ◽  
Mortality Factors ◽  
Nitrogen And Phosphorus ◽  
Reproductive Process ◽  
Breeding Sites ◽  
Iterative Model

The article discusses the expansion of the previously formulated approach to modeling aspects of the reproductive cycle, taking into account the changes in the habitat and metamorphosis in the development of fish. Excessive accumulation of nutrients with prolonged use of a reservoir for artificial growth of juveniles or accelerated decomposition of organic nitrogen and phosphorus may in some cases affect the success of the reproductive process. This creates an indirect effect on long-term trends in population dynamics. In some cases, the increase in the influx of organic phosphorus further leads to a state of eutrophication and may affect the insufficient aeration of breeding sites, leading to hypoxia for hatched larvae. Even worsen the situation with the consumption of oxygen in the water at the mass destruction of eggs. Lack of organic matter leads to insufficient development of planktonic organisms for optimal growth of fishes. The system of survivability equations for calculation competing individuals of the generation is supplemented by a functional extension using an iterative model of biogenic elements dynamics, based on the analysis of processes in the ecosystem of Lake Chao. The block of the model for calculating the inflow and destruction of organic matter is synchronized with a continuous-discrete computational structure that takes into account the interrelated changes in mortality factors and the rate of development of juvenile fish during transitions between generalized ecological and physiological stages of development.

Fish farming in Denmark: environmental impact of regulative legislation

1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen
Keyword(s):  
Organic Matter ◽  
Environmental Impact ◽  
Freshwater Fish ◽  
Aquatic Environment ◽  
Action Plan ◽  
Fish Farming ◽  
Fish Farms ◽  
Nitrogen And Phosphorus ◽  
Local Impact ◽  
The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

Sources and distribution of allochthonous organic matter in surface sediment from the Seomjin River to the southern inner shelf of Korea

2017 ◽  
Vol 52 (4) ◽  
pp. 489-499
Author(s):  
Adegoke Olugboyega Badejo ◽  
Sangmin Hyun ◽  
Wonnyon Kim ◽  
Se-Jong Ju ◽  
Bareum Song
Keyword(s):  
Organic Matter ◽  
Surface Sediment ◽  
Allochthonous Organic Matter ◽  
Inner Shelf ◽  
Seomjin River
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