Aquatic pests: marine and freshwater


Aquatic pests are harmful plants and animals that can be introduced to our waters from other countries or parts of Australia.

Aquatic pests include a wide range of salt and freshwater organisms from microscopic algae to species of seaweed, fish, barnacles, sea squirts, mussels and crabs.

Aquatic pests can significantly harm the Northern Territory's aquatic environment. 

They may threaten the biodiversity and native species, and affect commercial and recreational industries such as fishing, tourism, aquaculture and port operations.

Types of aquatic pests

This section provides information about all of the following, which are classes of pests under NT law:

  • aquatic pests
  • noxious fish
  • freshwater pests
  • marine (sea) pests.

Rules about aquatic pests

Marine pests can arrive on boats of all types and sizes. 

All boats coming in from overseas must be assessed for marine pests before they can enter any Darwin marina. 

Read about hull pest inspections for visiting boats.

Imported aquarium species can become pests if released, accidentally or deliberately, into natural waterways.

It is illegal to move any aquatic life from a water catchment or storage unit to another without authority.

Find out how to report aquatic pests and what to look out for.

Preventing aquatic pests

The NT Government's Aquatic Biosecurity Unit works with industry and community groups to monitor and manage the risk of new pests arriving in the NT.

This includes hull pest inspections for visiting boats, marine and freshwater pest control programs and a public awareness campaign of the affects of releasing non-native fish into NT waterways.

How you can prevent aquatic pests

To prevent both marine and freshwater pests becoming established, you should do all of the following:

  • regularly clean and check seawater systems on your boat.
  • anti-foul the hull of your boat every year
  • when cleaning your vessel or any gear, make sure no debris, including any organism, enters the water 
  • when out fishing, diving or boating, report aquatic pests including unusual aquatic growth or aquatic life in unnaturally high numbers
  • dispose of unwanted pond or aquarium fish humanely or check whether a local pet shop will take them - do not dump them in any waterway
  • prevent your outdoor ponds from overflowing during wet season rains
  • use attractive and colourful native fish and plants in your home aquarium and ponds.

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Last updated: 18 March 2016

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