The influence intenzity of eutrophication on fishpond yield

Abstract

Fish ponds have been always built for purpose of fish farming and some additional functions. We evaluated fish farming operation (in years 1990-2007) on the Sykovec and Medlov pond in altitude 700 meters above sea level and Jaroslavicky dolni pond in altitude 200 m. The samples for hydrochemical and hydrobiological analyses were taken regularly at monthly intervals in 2008. We chose some parameters as a total nitrogen (NT), total phosphor (PT), chlorophyll-a and chemical oxygen demand (COD) and structure of phytoplankton which has an impact on fish production. We compared our result with former research work from 1996-1997. Higher levels of monitored parameters have got a negative effect on spectrum of fish kind in managed fishponds.