Toxicity of ammonia,nitrite ion,nitrate ion,and orthophosphate to Mercenaria mercenaria and Crassostrea virginica

The 96-h lethal tolerance limits of the hard clam Mercenaria mercenaria (Linné) and the oyster Crassostrea virginica (Gmelin) to ammonia, nitrite ion, nitrate ion, and orthophosphate were defined. Sublethal effects of the chemicals upon the rates at which the shellfish removed algal cells from suspension were also studied. In comparison with other marine and aquatic species which have been studied, hard clams and oysters are extremely tolerant.