Environmental issues

Pests and weeds

Plague minnows

Plague minnows (Gambusia holbrooki) were introduced into Australia in 1925 to control mosquitoes (although they proved ineffective at this). Since then, they have become widespread in the waterways of south-eastern Australia. They are also found in the coastal drainages of Queensland, some parts of the Northern Territory and Western Australia.

These introduced fish can reproduce rapidly, disperse widely and occupy diverse habitats. They have a variety of impacts on native environments, including:

  • eating frogspawn and attacking the tadpoles of native frogs
  • preying on aquatic macroinvertebrates
  • attacking, injuring and preying on native fish
  • competing with native animals for food.

Plague minnows should never be released into our waterways.

Predation by the plague minnow - threat abatement plan
This plan examines the impacts of plague minnows on native animals, particularly threatened frogs. It sets out the management actions that are necessary to abate this threat.

Predation by the plague minnow (Gambusia holbrooki) - key threatening process listing
The NSW Scientific Committee has declared plague minnows to be a 'key threatening process' in NSW. See its reasons for making this declaration.

Page last updated: 03 November 2011