Exotic Fish In Australia
Numerous fish species have been released into the wild in Australia since European settlement commenced in 1778. Many of these species were deliberately introduced under government authority, a situation which would not be tolerated today.
Many of the species appear to have been introduced in the attempt to reproduce angling opportunities elsewhere and with little or no thought to the consequences for native fish.
Probably the best known are the salmonid group of which attempts have been made with varying success to establish populations of brown, rainbow and brook trout as well as Atlantic and Chinook salmon. Of these, brown trout have been the most successful in acclimatising to Australian conditions and rainbow trout are a close second being very widespread in cooler waters.
Also introduced for angling purposes have been redfin (English perch) and the coarse angling species carp, roach and tench.
One particularly problematic introduction has been that of the so-called mosquito fish, which did not even achieve the aim of those who introduced it and has caused considerable problems for small native species.
Several species have established populations as the result of liberations and escapes from aquarium use. The ubiquitous goldfish is widely distributed and, in the last decade or so, weather loach have made alarming in-roads in many waters. Also two species of cichlids (the black mangrove cichlid and the convict cichlid) have established self sustaining populations in the cooling pondage at the Hazelwood power station in Gippsland, Victoria.