QUALITY OF EFFLUENT WATER FROM EARTHERN FISH PONDS IN HUNGARY

The water quality of running water is determined mainly by the type of human activities within the catchment area, including fish culture. T he introduction of polyculture, the intensive application of fertilize rs, the use of manure and the development of fish-cum-duck culture hav e influenced water in fishponds and in pond effluents in both the grow ing and harvesting seasons. Natural waters serve as water supply for f ish production systems are characterized by an increased nutrient load . Government order No. 3/1984.(II.7.) OVH, based on the Government ord er No. 32/1964. (XII.13.) deals with the Water Utilization Act which i s concerned with the state requirements on release of industrial efflu ents. This Act divides the area of the country into 'zones of water qu ality protection', and determines the limits of pollution load for eac h water quality zone including penalties in case the limits prescribed in the Act are exceeded. Fish farms are also included into this Act. In 1988, a 2-year research programme was scarred to analyse the efflue nts of extensive and intensive gsh production syst ems from both envir onmental protection and economic standpoints. The goals of this resear ch programme were: (1) eo determine whether fish farm effluents meet t he state requirements given under Government order No. 3/1984.(II.7.) OVH at all times of the growing season and what pollution is caused in the recipient; (2) to describe the changes of water quality in the in flow and the outflow waters and in the recipient during the growing se ason and to collect data on possible water quality changes due to the seasonal drainage. These data should serve as a base for describing nu trient pathways in order to develop strategies for impact mitigation.