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

Previous studies have shown that the toxicity of ammonia to freshwater fishes depends on the ambient concentration of the un-ionized fraction (NH 3 ) and have quantified the percent NH 3 in solution as a function of temperature and pH. If NH 3 is also toxic to marine fishes, the effect of salinity on the ionization of ammonia must also be considered. The percent NH 3 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