A crucian carp Carassius carassius (L.) in Loch Rannoch, Scotland: further evidence of the threat posed to unique fish communities by introduction of alien fish species

1. This paper describes the discovery of a crucian carp Carassius carassius in Loch Rannoch, a species previously not recorded in this loch and only recorded in Scotland from five other lochs. 2. Establishment of fish species in a water body previously not containing that fish species can result in significant detrimental ecological changes within that water body, and once made, introductions are irreversible. 3. Given that such introductions are occurring with increased frequency it is recommended that (a) legislation is introduced to outlaw such translocations, and (b) parties with an interest in freshwater fish are educated to regard such translocations as unethical. (C) 1997 John Wiley & Sons, Ltd.