Effect of beryllium on fish in acid water is analogous to aluminum toxicity

Abstract

Trace metals such as aluminum, when mobilized by acid deposition, may be important toxic agents in acidified waters. Beryllium is chemically similar to aluminum, and its solubility and aqueous speciation properties suggest that it may also be a problem in some acidic waters. Elevated beryllium levels have been found in some waters, but little is known of the potential toxic effects of beryllium in soft water at low pH. We exposed juvenile perch Perca fluviatilis and roach Rutilus rutilus to beryllium at two levels of pH. Beryllium concentrations of 10 μg/l or more caused increased mortality at pH 4.5 in perch, but only higher concentrations (>50 μg/l) were lethal at pH 5.5. In roach, beryllium concentrations ≥100 μg/l killed most fish within 96 h, regardless of pH. Beryllium also produced gill abnormalities similar to those caused by aluminum at concentrations as low as 10 μg/l. The abnormalities became more severe at higher beryllium levels, and included development of chloride cell apical crypts, increased mucus production, microridge loss, epithelial hyperplasia, and fusions of primary lamellae. The effects of beryllium and aluminum are similar, but beryllium causes gill damage at lower concentrations, suggesting that it may be an important, unrecognized contaminant in some acidic waters.