The Good (or is that bad?): With a highly endemic fish fauna and a number of recently discovered species, and some pristine wilderness areas, Western Australia is good. However, over 20% of the freshwater or diadromous fishes appear on threatened species lists under national or state regulations (including ~half of the Southwestern Province’s fishes), and the list continues to grow. Long-term monitoring studies are assisting in the management of several species, including Balston’s Pygmy Perch (Nannatherina balstoni), Spotted Galaxias (Galaxias truttaceus), Freshwater Sawfish (Pristis pristis) and cave fishes.
The Bad (or is that ugly?): The number of bad fish species in Western Australia is climbing at almost at annual rate, with at least one recent invader, the Pearl Cichlid (Geophagus brasiliensis) spreading through estuaries and invading adjoining catchments. Some control events, such as the complete eradication of Redfin Perch (Perca fluviatilis) from a water supply reservoir have led to dramatic recolonisation of native species, while control programs for feral Goldfish (Carassius auratus) and other species have had some success in management outcomes and increased public awareness.
The Ugly: Along with bad fish came ugly things. In particularly, several introduced parasites have had severe impacts on native fishes. Although some native fishes are quite ugly, e.g. adult male Pouched Lamprey (Geotria australis), they can be good indicators of bad habitats.