Criteria for Aquatic Life DO
The water quality criterion for dissolved oxygen, therefore, takes these factors into account. Depending on the water temperature requirements for particular aquatic species at various life stages, the criteria values range from 5 to 9.5 mg/l, i.e. a minimum dissolved oxygen concentration of 5-6 mg/l for warm-water biota and 6.5-9.5 mg/l for cold-water biota. Higher oxygen concentrations are also relevant for early life stages. More details are given in Alabaster and Lloyd (1982) and the EPA (1976, 1986).