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:
- Degrading or compounding the degradation of aquatic ecosystems by stirring up sediment, undermining river banks and increasing nutrient levels
- Feeding on or destroying native aquatic plants
- Competing for native fish food/habitat and preying on native fish or frog eggs
- 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.
Once a pest becomes widely established, it is usually very difficult to eradicate. This is why it is critical to report sightings and to prevent the spread of pest fish into areas which we currently considered pest free. Where pest fish are firmly established, the focus is on trying to manage them and restore aquatic ecosystems, in order to tip the balance in favour of native fish and ecosystem health, which are interlinked.
To find out more about what is happening across Australia to control pest fish and protect native fish species, visit the Finterest website (click here)