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Pavlov D. S. Mochek A. D. Borisenko E. S. Degtev A. I. Shakirov R. R. Degtev E. A. 《Journal of Ichthyology》2006,46(2):S125-S133
Distribution of fish in the Gornoslinkinskaya Riverbed Depression in the Irtysh is considered in relation to the time of day and to the season. Fish aggregations are characterized quantitatively and by their size and species composition. The major part of the fish population of the depression consists of fish juveniles. The biological significance of the riverbed depression is polyfunctional. The universal traits of the ecosystems of large river basins and mechanisms of their occupation by fish are discussed. 相似文献
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D. S. Pavlov A. D. Mochek E. S. Borisenko E. A. Degtev A. I. Degtev 《Journal of Ichthyology》2009,49(11):1021-1031
Distribution, composition, and movements of fish within the floodplain-riverbed complex of the Lower Irtysh are investigated.
The principal working tools were hydroacoustic computerized complexes for the detection of fish aggregations and of their
movements in the floodplain water course. Twenty-four-hour hydroacoustic observations revealed the predominantly crepuscular-nocturnal
type of activity of most fish and the mass downstream migration of juveniles at the onset of the night. Seasonal traits of
formation of fish aggregations on key biotopes of the Irtysh are revealed, and their biological harmony is shown. The necessity
that fish distribution should be analyzed as a dynamic phenomenon is shown. 相似文献
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D. S. Pavlov A. D. Mochek E. S. Borisenko A. I. Degtev E. A. Degtev 《Inland Water Biology》2011,4(2):223-231
The composition of fish, their location and movements in the channel, channel depressions, and flood waters of the lower reaches
of the Irtysh River are investigated. This study is conducted with computer sonar systems used for different purposes. Diurnal
and seasonal dynamics of movements of the fish and the abundance and composition of fish aggregations are revealed in the
studied sites. The biological unity of the fish community of the floodplain-channel complex is demonstrated. 相似文献
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An original method of taxonomic identification of fish (at the family level) by means of hydroacoustic equipment is elaborated.
The method is based on analysis of the form of instantaneous envelope of amplitudes of the acoustic signal reflected from
fish. Analysis of distribution of mass fish of different size over horizons of the water column is made on the deep-water
riverbed depression of the Irtysh and characteristics of their diurnal vertical migration are revealed. 相似文献
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“Netcor” computer-aided hydroacoustic system has been used to study the pattern of spawning migration in the Shuya River of
the Atlantic salmon Salmo Salar inhabiting Onega Lake. The migrants’ length frequency and abundance have been evaluated, and the pattern of their spawning
run, as referring to observation days and the time of day, has been determined. The data obtained with the use of the hydroacoustic
system have been compared with those from a fish-counting trap at a fish-counting barrier (FCB). Hydroacoustic systems have
been shown to perform better in studies of anadromous fish migration and in the determination of migrants’ abundance and the
cycling and direction of their movements. 相似文献
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Hydroacoustic characteristics of mass fish species of the Ob-Irtysh Basin are investigated for elaboration of instrumental methods of fish identification by the results of hydroacoustic surveys. Linear-logarithmic regression equations of average values of the acoustic “target strength” are obtained, depending on the body length and weight of located objects. Instant values of the form of the echo signal envelope of amplitudes of echo signals from fish are analyzed. The numerical values of their statistical parameters are obtained. The characteristics of the backscattering from different species may be used for the solution of practical tasks of identification of fish and estimation of bioresources on inland water bodies. 相似文献
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D. S. Pavlov A. D. Mochek E. S. Borisenko E. A. Degtev A. I. Degtev 《Journal of Ichthyology》2010,50(11):997-1001
An original method for estimation of the effect of bottom irregularities on density of fish aggregations is elaborated. Calculation
of the investigated relationship is based on material of surveys collected by an AsCor hydroacoustic complex and is made by
means of special software. With reference to a deep-water stretch of the Irtysh channel, the quantitative parameters of the
relationship between densities of fish aggregations and the index of bottom irregularity are revealed. The diagram of the
relationship between bottom irregularities and density of fish aggregations, the three-dimensional model of bottom relief
of the investigated water area, and echograms of fish aggregations on various stretches of the river are presented. 相似文献
9.
D. S. Pavlov A. D. Mochek E. S. Borisenko A. I. Degtev E. A. Degtev 《Journal of Ichthyology》2008,48(11):919-936
We present the results of ichthyological studies in principal channel depressions of the Irtysh developing the notions on
polyfunctional biological role of these formations. The study is made by means of a computerized hydroacoustic complex “Askor”.
Quantitative estimation of the size composition, abundance, density, and spatial distribution of fish on water area of channel
depressions in different seasons confirms the hypothesis of multifaceted biological significance of these formations. Universal
traits in the organization of fish aggregations, specificity of distribution, composition, and seasonal dynamics of the fish
population on the largest channel depressions of the Irtysh are revealed. 相似文献
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