The environmental and social values of the Yarra are related to it being home for a wide variety of plants and animals, especially indigenous species. However, the number and population of native species are severely affected by the spread of introduced species, notably weeds, exotic fish, domestic stock and feral animals. Nonetheless the circumstances vary widely along the river and across the catchment. In the older urban areas exotic garden plants and pet animals are valued by the community. On sporting fields and golf links, open mowed exotic grass is the norm. In agricultural areas, stock animals and food crops are intended. It is in the parks, bushland and the waterway itself where the objective is for only indigenous species.
Revegetation with indigenous plant species is being undertaken by many community groups and most local authorities, and there are numerous success stories. But the attractiveness of exotic plants and animals, and the fact that many out-compete native species are formidable barriers, such that it is doubtful whether the overall situation is improving.
All the flora and fauna of the Yarra catchment are indigenous species except:
