Ionization of Ammonia in Seawater: Effects of Temperature, pH, and Salinity

Abstract

Previous studies have shown that the toxicity of ammonia to freshwater fishes depends on the ambient concentration of the un-ionized fraction (NH₃) and have quantified the percent NH₃ in solution as a function of temperature and pH. If NH₃ is also toxic to marine fishes, the effect of salinity on the ionization of ammonia must also be considered. The percent NH₃ over ranges of temperature, pH, and salinity common in seawater-culture situations is presented here. Key words: ammonia, ammonia analysis, ammonia ionization, ammonia toxicity, pH, salinity, temperature