TOXICITY OF ACID ALUMINUM-RICH WATER TO 7 FRESH-WATER FISH SPECIES - A COMPARATIVE LABORATORY STUDY

The present study focuses on the relative sensitivity among freshwater fish species to aqueous aluminium. Seven common Scandinavian fish spe cies were exposed to acidic Al-rich water, acidic Al-poor water, and a pproximately neutral water as a control. The relative sensitivity amon g the species to an acute aluminium challenge was documented, and was in the following order : Atlantic salmon, Salmo salar, as the most sen sitive, then roach, Rutilus rutilus, minnow, Phoxinus phoxinus; perch, Perca fluviatilis; grayling, Thymallus thymallus, brown trout, Salmo trutta,. and Arctic char, Salvelinus alpinus, Substantial mortality wa s observed in all species when exposed to the Al-rich medium. Some mor tality was also observed in minnow, roach, and brown trout exposed to the acidic Al-poor medium and the control medium. A high resistance to aluminium was observed in Arctic char, while perch was found to be mo re sensitive to aluminium than expected and,for the first time, a toxi c response to aqueous aluminium in grayling was documented. Through co ntrolled experimental studies, the results confirm that aluminium is a n important factor in the toxicity of acidified waters to freshwater f ish species. (C) 1997 Elsevier Science Ltd.