Preliminary communication
OXYGEN DYNAMICS IN THE WATER OF CARP PONDS IN THE FUNCTION OF THE INTENSIFICATION OF PRODUCTION
Ljubica Debeljak
; Agronomski Fakultet u Zagrebu
Ž. Bebek
Krešo Fašaić
Abstract
The fisheries »D. Miholjac« was investigated in 9 nursery ponds with individual sizes of 8-10 ha. In nursery ponds A, B, C and D were cultured year old carp and in nursery ponds E, F, G, H and I were cultured carp fry. Investigated was the hydrochemical dynamics, plankton quantity and zoo benthos, as well as the relation betyeen the oxygen amount dissolved in the water the quick test of biochemical oxygen consumption (BPK-24 hours), production of fish and relative feeding coefficient in conditions with supplement food of grains and mixtures in the form of pastry.
The results of investigations are illustrated in Tables 1 and 2 and in Figures 1-3. At the time of investigation the hydrochemical conditions were satisfactory except for the quantity of dissolved oxygen and biochemical oxygen consumption (BPK-24 hours), which ranged from levels of 2.56 mg/l to 9.44 mg/l (30 to 111%) and from 1.2 mg/l-24 hours to 7.68 mg/l-24 hours.
A very marked correlation was established between the amount of dissolved oxygen, biochemical oxygen consumption, abundance of plankton, water transparency and the relative feeding coefficient. The growth rate values of biochemical oxygen consumption and the decrease of the amount of dissolved oxygen of the ponds in which the fish are supplemented with the food mixture resulted in an increase of the relative feeding coefficient and a decrease in the growth rate of fish.
Keywords
OXYGEN DYNAMICS; CARP PONDS; PRODUCTION
Hrčak ID:
76747
URI
Publication date:
1.3.1989.
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