Limnological investigations of a fish-pond supplied with sewage-water in the vicinity of Lake Balaton. I.

Ponyi, Jenő and Biró, Péter and Oláh, János and P.-Zánkai, Nóra and Tamás, Gizella and Csekei, Tibor and Kiss, György and Morvai, Tibor and Bancsi, István (1973) Limnological investigations of a fish-pond supplied with sewage-water in the vicinity of Lake Balaton. I. A Magyar Tudományos Akadémia Tihanyi Biológiai Kutatóintézetének évkönyve, 40. pp. 227-284. ISSN 0365-3005

Preview

Text 228_cut_MTA_TihanyiBiologiaiKutIntEvkonyve_40.pdf Download (35MB) | Preview

Abstract

1. The distribution of the total planktonic biomass is uneven in the transversal section of pond No. 1, namely it is about 4—7 percent lower in the vicinity of the inflow of sewage-water than at other places. 2. The zooplankton plays a secondary role in th e planktonic community during the warm-water period as compared to the algal biomass. 3. The almost complete absence of Daphnia species as well as these condary role of the other Cladocera during the summer season indicate a limited transfer of the algal biomass increased by the sewage-water along the food-chain. 4. On the basis of the bacterial biomass, pond No. 1 can be classified to be of high productivity and medium loading. 5. The boggy soil of the pond is rich in organic substances (N, P₂O₅) iron and sulphate ions. There exist a danger of th e formation of H₂S because of the O₂-shortage at the mud-surface during summer. 6. The data of production of the ponds testify that carp-production is generally high and apart from the varying mortality, it depends on the quantity and quality of the fishes planted as well as on the feeding. Pond No. 1 but the other two also are qualified to be of medium or low productivity. 7. The rate of growth of different fishes varied in pond No. 1; the increase of body weight and length of carp lagged that of other fishes. Its mortality was high, survival rate was low. 8. The slow growth of carp can be explained by th e poorness of the natural food of animal origin. 9. The white and spotty grass-carps consuming algae and small benthic animals displayed intense growth, showed a lower mortality and the best adaptation to the given circumstances.

Actions (login required)

Edit Item