Begell House Inc.
Hydrobiological Journal
HYD
0018-8166
37
1
2001
A Simple Model of a Lake Ecosystem for the Study of Relationships between its Components
12
10.1615/HydrobJ.v37.i1.10
A.F.
Alimov
Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia
A. A.
Umnov
Institute of Zoology Russian Academy of Sciences St. Petersburg, Russia
A simple model of a lake ecosystem consisting of autotrophic and heterotrophic organisms, and also of organic matter both suspended in water and accumulated in bottom sediments, has been studied. The processes of production and decomposition of organic matter were simulated by using the general equations governing the main relationships in the ecosystem. It has been found that the capacity of the ecosystem for stabilization at the expense of the intra-ecosystem relationships is its main characteristics Production of the communities of heterotrophic organisms incorporated into the ecosystem may depend to a large extent on the structure of ration of animals. Production, P/B coefficients, and the efficiency of functioning of the ecosystem belong to its main characteristics. The values of Р/B coefficients and the efficiency of functioning of the ecosystem are higher than those of the populations and communities of hydrobionts. Simplification in the structure of an ecosystem is accompanied by the increase in values of P/B coefficients and the efficiency of its functioning.
Formation of the Structure of Algal Communities of the Desna River
11
10.1615/HydrobJ.v37.i1.20
T. N.
Sereda
Institute of Hydrobiology National Academy of Sciences of Ukraine Kiev, Ukraine
Based on the river continuum concept, the peculiarities and ecological conditions of formation of the structure of algal communities of the Desna river, and their spatial and temporal distribution have been studied.
Influence of Free Carbon Dioxide on the Viability of Phytophilous and Pelagophilous Fishes in Early Ontogeny
13
10.1615/HydrobJ.v37.i1.30
S. V.
Kruzhilina
Institute of Fishery, Ukrainian Academy of Agrarian Sciences, Kyiv, Ukraine
V. P.
Bil'ko
Institute of Hydrobiology, National Academy of Sciences of Ukraine, Kiev, Ukraine
It is shown experimentally that viability of fish embryos depends on the CO2 concentrations in aquatic medium at the period of fecundation and swelling of eggs. CO2 concentrations of 8-9 mg/L stimulated vitality of larvae of phytophilous fishes. Proceeding from the results obtained, the authors recommend the standards of CO2 concentrations at various dimensional stages of fish (in particular, white amur, white bullhead, bream) breeding in ponds.
Nutrition of Whiting (Merlangus merlangus euxinus (Nordmann) (Gadiformes, Gadidae) in Different Areas of the Black Sea
14
10.1615/HydrobJ.v37.i1.40
N. T.
Shevchenko
Institute of Biology of the Southern Seas National Academy of Sciences of Ukraine Sevastopol, Ukraine
The nutrition of whiting, Merlangus merlangus euxinus, in different parts of the Black Sea has been studied. The data on peculiarities of its food composition in different marine areas and seasons are analyzed.
A Method for Determining the Validity of Assessments of Abundance and Biomass of Phytoplankton Communities in the Black Sea
7
10.1615/HydrobJ.v37.i1.50
Yu. V.
Bryantseva
M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine,
2 Tereschenkivska Str., Kiev 01601, Ukraine
L. A.
Koval'chuk
Southern Research Institute of Fisheries and Oceanography Kerch, Crimea, Ukraine
The registration of environmental habitat areas and of statistical laws of the phytoplankton specific biomass and its abundance distribution makes possible to assess correctly the phytoplankton stock in the Black Sea on the base of traditional observations. Calculated average indices of specific abundance and biomass in different areas of the sea are recommended for optimization of the observation and monitoring system.
The Use of Infrared Spectroscopy for the Study of the Impact of Active Chlorine on Seawater and Communities of Periphyton Microorganisms
7
10.1615/HydrobJ.v37.i1.60
L. A.
Georga-Kopulos
Institute of Biology of the Southern Seas National Academy of Sciences of Ukraine Sevastopol, Ukraine
L. L.
Smimova
Institute of Biology of the Southern Seas National Academy of Sciences of Ukraine Sevastopol, Ukraine
The IR-spectroscopy results demonstrated that active chlorine in seawater increases the overall toxicity of environment. At low concentrations (up to 0.2 mg/L), this is a result of the formation of organochlorines, and in high concentrations — of peroxide fragments. The threshold concentration of active chlorine for a community of periphyton organisms is 3.0 mg/L; its further growth results in the irreversible oxidative destruction of organic matter of cenosis, and eventually to its death.
The Study of Benthic Microflora by a Near-bottom Disk
6
10.1615/HydrobJ.v37.i1.70
V. A.
Terekhova
Institute of Ecology of the Volga Basin Russian Academy of Science Tol'yatti, Russia
T. A.
Semenova
Institute of Ecology of the Volga Basin Russian Academy of Science Tol'yatti, Russia
A novel construction of a benthic disk was suggested to study development of two groups of aquatic fungi of benthic communities. A long-term exposure of bait-containing microboxes attached to the disk has revealed an intensive accumulation of biomass of typical aquatic oomycetes at the near-bottom level. Experiments with soil oomycetes demonstrated the ability of some of their species to develop both in water and in bottom sediments.
Bottom Sediments of Reservoirs as a Potential Source of Secondary Pollution of the Aquatic Environment by Heavy Metal Compounds
14
10.1615/HydrobJ.v37.i1.80
The article reports the results of long-term investigations of pollution of bottom sediments in the Dnieper water bodies by heavy metals. The most probable ways of heavy metals exchange between the bottom sediments and the contacting aquatic environment are considered. It is shown that the intensity of exchange processes depends not on the total content of heavy metals in bottom sediments, but rather on their existing forms in composition of both the solid substrata and interstitial solutions. The assessment is made of migration mobility of the investigated heavy metals and their exchange capacity.
Principles of Mathematical Modeling of Processes of Physicochemical and Biological Self-purification in Aquatic Ecosystems
25
10.1615/HydrobJ.v37.i1.90
V. I.
Lavryk
Kyiv-Mogyla National University Kyiv, Ukraine
The survey presented considers the factors acting in aquatic ecosystems and influencing the water quality of land surface waters. The significance and interaction of these factors are illustrated by imitative mathematical models developed by the author to analyze and forecast the dynamics of major indexes (components) of a hydroecosystem state.
The Structure and Composition of Pelagic Communities of the Estuarine Region of the Vita River
11
10.1615/HydrobJ.v37.i1.100
Yu. F.
Gromova
Institute of Hydrobiology, National Academy of Sciences of Ukraine Kyiv, 04210, Ukraine
The structure and composition of phytoplankton, zooplankton, and fish fauna of the estuarine region of the Vita river were studied. It has been found that periodic fluctuations in the direction and velocity of flow essentially influence the formation of plankton communities. The maximum quantitative indices of development of the biota were registered in semi-flowing water bodies. On the whole, plankton of the estuarine region is more diverse in its species composition than that registered in the river taken alone, and also than plankton occurring in the adjacent sections of the Kanev reservoir.
A Gradient Analysis of Algal Communities of an Urban River (on the Example of the Nivka River)
6
10.1615/HydrobJ.v37.i1.110
The peculiarities of formation of algal communities in urban watercourses were studied on the example of the Nivka river. The character and extent of anthropic load on an ecosystem have a dominant role in this process. The floristic spectrum of algae is simplified. For the most part, the complex of dominant species includes commonly occurring algae.
Ecological Standards of Water Quality for the Ros river
8
10.1615/HydrobJ.v37.i1.120
V. N.
Zhukinskiy
Institute of Hydrobiology, National Academy of Sciences of Ukraine, Kiev, Ukraine
Ecological standards of water quality (optimal and permissible values) for the Ros river were established in terms of the following indices: salt content, trophic and saprobic indices, and also the content of specific substances of toxic and radiation action. The modem state of water quality of the Ros river was assessed with regard to ecological standards for this river.