Recently NO3-N concentrations of the rivers that flow into the Kasumigaura lake have increased. The lake is much eutrophicated and is used as a source of water supply for Tsuchiura-city. Stocking density and NO3-N specific load have a high correlation (r=0.93). NO3-N concentrations increase corresponding to the increase of stocking density. In this area the livestock has a larger influence to the nitrogen concentration of the rivers than the land use.
The impact of stocking density and dietary carbon sources on the growth, oxidative status and stress markers of Nile tilapia (Oreochromis niloticus) reared under biofloc conditions
