Many fish species have been introduced into NSW waters over the past 200 years, both intentionally and accidentally. It's still happening today. These species arrive from interstate or overseas and invade marine or freshwater environments. Some species, including plants, animals and seaweeds, have established themselves in NSW and are now regarded as pests. For example, the invasive freshwater fish redfin perch Perca fluviatilis is listed as a noxious pest and is of major concern in NSW

Pest species can threaten indigenous aquatic and terrestrial life directly as predators and/or competitors for food or indirectly by altering their natural habitat. It's believed pests contribute to the decline of some threatened native species.

Introduced pathogens and parasites not detected by quarantine controls, can also threaten native biodiversity by causing diseases in native species.

Responsibility for the prevention and management of aquatic pests and diseases is shared between several State and Commonwealth government agencies. NSW DPI has responsibilities for the conservation and management of the fish and marine vegetation of NSW, and this includes the management of pest species and diseases.

IN THIS SECTION

• Freshwater pest fish
  Information about freshwater fish that are pests in NSW, their introduction, spread and impacts, and what NSW DPI is doing.
• Marine pests
  Information about pests in the marine and coastal environment, including the noxious seaweed Caulerpa taxifolia, pests carried in ballast water and as biofouling on boats, how to identify these species and what NSW DPI is doing.
• Aquatic animal health
  Information about diseases in fish and shellfish including QX oyster disease, Pacific Oyster Mortality Syndrome and nodavirus in Australian bass, and what is being done to better understand and manage these diseases.
• Reporting and responding to pests and diseases
  How to report suspected pest species, or unusual disease signs or unexplained deaths in cultured or wild fish. Also outlines how NSW DPI responds to pest and disease emergencies.
• Legislation and regulations
  Information on NSW noxious fish (including those that are banned), importation of fish from interstate, quarantine issues, and links to Aquaculture policies and permit requirements.
• Key contacts