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