Haematological and physiological responses of brook charr, to untreated and limestone-neutralized acid mine drainage

Brook charr, Salvelinus fontinalis, exhibited depressed plasma sodium and elevated plasma glucose concentrations in untreated acid mine drainage effluent (AMD), at two dilutions. Plasma sodium and glucose concentrations remained stable in treated AMD, pulsed, fluidized beds of limestone and carbon-dioxide pre-treatment of influent, and in AMD-free water. Results indicate that effluents produced by this treatment system were not toxic to these fish, despite still containing moderate concentrations of manganese (3–4 mg l^-1 following dilution in exposure systems), and provide justification for field deployment and further biological testing of this treatment in the field.