Feral fish

Why Target Feral Fish?

Since European settlement, the deliberate or accidental introduction of non-native fish into Australian freshwater ecosystems has resulted in the establishment of many populations of pest fish species. These species are broadly considered as 'pests' because they threaten native fish species, river health and aquatic ecosystems by:

1. Degrading or compounding the degradation of aquatic ecosystems by stirring up sediment, undermining river banks and increasing nutrient levels
2. Feeding on or destroying native aquatic plants
3. Competing for native fish food/habitat and preying on native fish or frog eggs
4. Spreading disease and parasites that can adversely impact native species.

Pests such as European carp (also called Common carp), Redfin perch, Eastern gambusia, Oriental weatherloach and Goldfish are listed as 'noxious' in NSW by the NSW Department of Primary Industries, and are listed as a pest species by the ACT Government.

These fish are found in many rivers, but exactly where they occur is poorly known.

Although we know roughly how these species are impacting our rivers, lakes and creek systems, we don’t have detailed catchment-wide data on where these pest fish are found or their numbers. We need your help to address this knowledge gap to better manage the effects of pest fish throughout our wonderful catchment. FeralFishScan is a community website managed by the Invasive Animals Cooperative Research Centre and dedicated to collecting evidence of feral fish in our freshwater rivers.

You can help by recording sightings of pest fish in the FeralFishScan community mapping facility for your catchment area. This data will then be available for everyone to see and use.

Report sightings of pest fish

Early detection of an aquatic pest population is critical! Once a pest fish has established in an area, it is very difficult, if not impossible to eradicate. In addition to recording your sightings on the FeralFishScan website, you can help by reporting it to the NSW Department of Primary Industries (DPI) Aquatic Biosecurity unit. For more information visit the DPI website, phone 02 4916 3877 (recorded 24 hour service), or email aquatic.pests@industry.nsw.gov.au

Healthy habitat = healthy native fish populations

Healthy habitat is critical to improving native fish populations. Native fish populations in the Murray–Darling Basin are estimated to be at just 10% of pre-European levels.

The DPI Conservation Action Unit rehabilitates fish habitat and native fish populations in NSW. Healthy habitats help native fish to be more resilient against the impacts of alien fish.

For more information on aquatic habitats and aquatic rehabilitation visit the DPI website or phone 02 6881 1270.

How to Identify Carp and other feral fish species

Do you know which fish species you've seen? There are 5 major feral fish species that live in the Upper Murrumbidgee catchment. They are:

• Common carp
• Redfin perch
• Eastern gambusia
• Oriental weatherloach and
• Goldfish

There are also some native species that can be easily mistaken for feral fish. The FeralFishScan website provides information on how to easily identify feral fish.

General information regarding all live fish in your possession

• Do not release any alien fish into a waterway – it is illegal.
• Design fishponds so that plants, snails, fish or eggs can not escape during heavy rains, and screen all overflow areas.
• Don’t return pest fish to the water – if you catch a pest fish dispatch it humanely and utilise or dispose of it appropriately.

More information

• Pest fish and diseases - DPI (NSW)
• To find out more about what is happening across Australia to control pest fish and protect native fish species, visit the Finterest website.
• Small fish guide