L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 6. 1991 (Budapest, 1991)

Csányi, B.: Changes of the fish assemblages in the Kis-Balaton Reservoir between 1985 and 1989

CONCLUSIONS The basic purpose of the fish-faunistical research was to reveal the process of colonization. After two years of study our advise to reservoir management authorities was to let the stock reproduce itself and colonize new habitats without any control. The colonization and the diversification of the initial fish fauna was indicated in the second year already. This change was essential for the improvement of water quality and the nutrient uptake: the more diverse trophic network means the higher efficiency of nutrient removal. However, the responsible authorities decided to give the fishing licence to the Balaton Fishing Cooperative and the local permission to anglers after three years in order to promote the multilateral utilization of the reservoir. According to our opinion, this decision was made too early: 1. The stabilization of the fish fauna was not proved; 2. The detailed description of hydrobiological processes were not achieved. The important changes of the community structure indicated in our study support the need of controlled interventions. A comprehensive fish management strategy can be proposed only in case of detailed knowledge about the mass and energy transport processes taking place in the reservoir, including all kinds of important compartments of the biota. REFERENCES BERINKEY, L, (1972): Magyarország és a szomszédos területek édesvízi halai a Természettudományi Múzeum gyűjteményében (Süsswasserfische von Ungarn und der angenzenden Gebiete in der Sammlung des Ungarischen Naturwissenschaftlichen Museums). - Vertebr. Hung., 13: 3-24. BÍRÓ, P. (1990): Zárójelentés "A Kis-Balaton Védőrendszerben és a csatlakozó vízgyűjtő vizeiben a halállomány feltárása és a gazdasági hasznosítás lehetőségeinek megismerése" c, G-10 jelű OKKFT Program keretében végzett kutatásokról (1988-1990). Manuscript. CHESSEL, E. D. (1978): Description non paramétrique de la dispersion spatiale des individues d une espèce, p. 45-135. - In: J. M. & R. TOMASSONE (eds): Biométrie et écologie. Société français de Biométrie. COPR G.H. (1990): Experimental design in fluvial ichthyology. - Ann. Rep. F.BA.., 58:68-86. CSÁNYI, B., P. GULYÁS & J. NÉMETH (1989): Hydrobiological survey of the Kis-Balaton Reservoir. - In: J. SALÁNKI & S. HERODEK (eds): Conservation and Management of Lakes, Symp. Biol. Hung., 38 : 517-527. Akadémiai Kiadó, Budapest. GÉRARD, G. & P. BERTHET (1971): Sampling strategy in censusing patchy populations, p. 59-67. - In: G. P. PATIL, E. C. PILOU & W. E. WATERS (eds): Statistical Ecology. Penn. State Univ. Press, USA LEGENDRE, L & P. LEGENDRE (1983): Numerical Ecology. - Elsevier Sei. Publ. Co., Amsterdam, Oxford, New York. p. 1-419. MANN, R. H. K & T. PENCZAK (1986): Fish production in rivers: A review. PoL Arch. Hydrobiol., 33:233-247. NELVA, A., H. PERSAT & D. CHESSEL (1979): Une nouvelle méthode d'étude