The cyanide sensitivity of some aquatic species about the cyanide contamination of Tisza River

Abstract

The catastrophic cyanide contamination of Tisza River in 2000 (which came from Romania) was accompanied with a mass death of more than l’OOO tons of fish. Then, we have seen the needs to determine the 50 per cent lethal values (LC50) of potassium cyanide (KCN) for Palingenia longicauda larvae. Above this organism, we also determined this value for seven other invertebrate species and for three Teleost fishes. Furthermore, we have investigated the accumulation of some heavy metal ions in Palingenia longicauda larvae and in some other invertebrates. Our results show that among all creatures investigated so far, Palingenia longicauda larvae belong to the most sensitive organisms to the toxic effect of KCN. In spite of this, the organism survived the cyanide contamination much better than we have thought.
Another part of our program runs under the title “Efforts for the Resettling of Palingenia longicauda in Its Former Range in Hungarian and German Rivers”. This task needs a lot of preliminary investigations. Now it seems that the resettling of Palingenia longicauda could have, above pure nature conservation benefits, further favorable effects on the traffic of aquatic material as well.