Prevent the spread of invasive freshwater animals

How invasive freshwater animals (e.g. fish, snails, crayfish) spread

You introduce invasive freshwater animals to our waterways when you:

• dump aquarium animals into creeks and ponds (e.g. goldfish, sailfin mollies, guppies, platys, cichlids, apple snails)
• use them as sportfish (e.g. carp, salmon, perch, trout)
• use fish from other catchments as live bait (e.g. tilapia)
• stock the wrong fish for their natural area into dams and ponds which overflow into other waterways (e.g. banded grunter).

If you find a freshwater invasive animal that is not native to the area, call the Customer Service Centre on 13 25 23 or report it online.

How to prevent invasive freshwater animals being introduced to our waterways

Unless you have a permit, it’s an offence to stock your farm dam with fish that don’t occur naturally in your area. Stocking the wrong fish in your dam may lead to irreversible changes to local fish populations if the fish escape from your dam during floods.

You are allowed to put permitted freshwater species (i.e. not prohibited or restricted noxious fish or snails) into ornamental ponds, as long as they cannot escape during times of high rainfall. A better alternative would be to put native fish or snails in your outdoor ponds. Native fish are great for ponds as they control mosquitoes, have interesting colours and shapes, and some larger species, have their own personality.

Never dump your aquarium contents into waterways or flush them down the toilet, as the water will eventually end up in our waterways.

Recreational fishers

• Don't transfer invasive fish between waterways—don't use invasive fish as bait.
• Obtain a permit to stock fish. Buy fingerlings from a registered hatchery to minimise the chance of contamination with undesirable species.
• Don't return invasive fish to the water. If you catch an invasive fish, kill it humanely and dispose appropriately.
• Prevent unwanted hitchhikers—check, clean and dry your boats and gear between waterways.

Ornamental fish and snail enthusiasts and backyard pond owners

• Don't dump fish, snails or crayfish—give unwanted aquarium animals to friends or a pet shop instead of letting them go in the wild.
• Prevent accidental escapes—screen outdoor ponds to prevent overflow during heavy rains.
• If possible, keep native animals instead of exotics—contact your local aquarium or Customer Service Centre on 13 25 23 for information on local native fish or animal species.
• Find out the natural range of Queensland freshwater species.

Unwanted pets

If you no longer want fish, snails or crayfish that are in your aquarium, contact your local pet shop or aquarium who may take them. If not, Biosecurity Queensland advocates following ethical euthanasia protocols recommended by the 2001 ANZCCART publication Euthanasia of animals used for scientific purposes (PDF, 1.8kb). The most appropriate method for fish may involve stunning via a sharp blow to the back of the head causing brain destruction.

Do not transport fish between catchments to use as bait. Live bait may escape and dead bait may still be holding viable eggs.

Removing invasive freshwater animals once they have established

Once invasive fish or snails have established in a waterway, it’s very difficult—if not impossible—to remove them. It’s much better to prevent their introduction and/or spread by educating people about the negative impacts of invasive animals.

How you can help

To help stop the spread of invasive freshwater animals:

• Don’t keep or bring invasive animals (e.g. fish or snails) into Queensland.
• Avoid spreading invasive fish between waterways.
• Report sightings of invasive freshwater animals.