Colour cartoon of man dumping aquarium fish into a river. He hopes no one is looking! There is growing community concern at both national and State level regarding the impact of exotic species such as carp (Cyprinus carpio) and tilapia (Oreochromis mossambicus and Tilapia mariae) on native fishes and their habitats.

While the impacts of such introductions are already serious in some parts of Queensland, it is apparent that there is potential for greater impact in the future if well-coordinated and directed action is not taken now.

A State Strategy for the control of exotic pest is being developed by the Department of Primary Industries.

Seventeen species of exotic fish are listed as noxious under the Fisheries Regulation 1995.

Hybrids of these noxious fish are also considered noxious.

This list was compiled in response to a call for a nationally consistent noxious fish list and as such there are a number of species that have never been recorded in Queensland waters but are a threat nationally.

In Queensland, three species or species groups have established significant self-maintaining populations - carp, tilapia and gambusia (mosquito fish).

Definitions

colour cartoon of an goldfish - an exotic pest fish In the Queensland Fisheries Regulation 1995, only 17 species of fish are declared noxious.

Therefore it was considered to be more inclusive to use the term 'exotic pest fish' to cover all exotic species that presently cause harm, or have the potential to cause harm to the native aquatic environment.

It is presently thought that the number of exotic finfish species recorded in the wild in Australia is at least 43 (Arthington et al. 1999).

Table 1. Species declared noxious under The Fisheries Act 1994 (Qld).

Common name	Scientific name
Bluegill	Lepomis spp.
Chinese weatherfish (weatherloach)	Misgurnus anguillicaudatus
Electric eel	Electrophorus electricus
Carp	Cyprinus carpio
Climbing perch	Anabus testudies
Grass carp	Ctenopharyngodon idella
Largemouth bass	Micropterus salmoides
Gambusia or mosquitofish	Gambusia spp.
Nile perch (live)	Lates niloticus
Parasitic or candiru or pencil catfish	Family Trichomycteridae
Pike cichlid	Crenicichla spp.
Snakehead	Channa spp.
Tiger catfish	Pseudoplatystoma fasciatum
Tigerfish (African)	Hydrocynus spp., subfamilies Hydrocinae and Alestinae
Tigerfish (South American) or trahira	Erythrinus, Hoplerythrinus and Hoplias spp.
Tilapia	Tilapia, Oreochromis or Sarotherodon spp.
Walking catfish	Family Clariidae
Piranhas, pacus and allies	Fish of family Serrasalmidae or subfamily Serrasalminae, except Meynnis spp. and Myleus rubrippinis

Species risk assessment

All 16 species that have established populations in Queensland waters should be considered to present some degree of risk, and their populations monitored to establish current distribution and trends in range expansion.

These species have been examined further using risk assessment criteria based on those found in the National Translocation Policy for Live Aquatic Organisms (1999).

These criteria have been modified slightly because the strategy will operate at the State level.

The results confirm that tilapia, carp and gambusia have the greatest potential to cause damage to native fishes and their habitats.

Some other species, for example some of the cichlids such as the red devil and the oscar, do show the potential to become pests. However, it would be inappropriate to label them as such until there is more information about their potential impacts.

back to home page |next page: Table 2 - species established in Queensland waters