Читать книгу Fundamentals of Aquatic Veterinary Medicine - Группа авторов - Страница 33

The nitrogen (N₂) biogeochemistry of aquaculture ponds is dominated by biological transformations of nitrogen added to ponds in the form of inorganic or organic fertilizers and formulated feeds. Nitrogen application in excess of pond assimilatory capacity can lead to the deterioration of water quality through the accumulation of nitrogenous compounds (e.g., ammonia and nitrite) toxic to the fauna. Principal sources of nitrogen include animal excretion and sediment flux derived from the mineralization of organic matter and molecular diffusion from reduced sediment, although cyanobacterial nitrogen fixation and atmospheric deposition are occasionally important.