Different qualities of bream populations in the reservoirs of Belarus | О разнокачественности популяций леща водоемов Беларуси
2010
Kostousov, V.G., National Academy of Sciences. Scientific and Practical Center of Animal Breeding (Belarus). Institute for Fish Industry | Rizevskij, V.K., National Academy of Sciences (Belarus). The Scientific and Practical Center for Bioresources
Different qualities of bream (Abramis) populations in reservoirs were studied in the conditions of the Republic of Belarus. It was show that intraspecies variability can be observed depending on the type of wetlands and is reflected in the differences of the growth rate, in puberty age and the age structure of stock. The greatest difference in attributes is typical in lentic water systems, the least one is typical for running water systems. In lakes the different qualities of bream populations are identified due to morphometric and trophic characteristics and regulated by the stock population number. Age content of bream catch was analysed according to the year. There were presented middle size-age indexes of bream growing from trade catches of ponds and channel erosion. There were presented average indexes of line and weight bream growing of different ponds. There was analysed the dynamics of bream ichtyomass with different growth rate and coefficient of natural mortality of 22%. Research results showed that different qualities of bream depended on adaptive character of population connection with particulars of morphometric and trophic pond characteristics and were established by relative school number and fish catching. There were the best conditions for growth in the ponds where intertidal zone square was not more than 20% from total square and long of beach profile was 2,5 of pond square.
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