This paper provides a review of the current state of knowledge on the impacts of displaced/introduced fauna (fish and invertebrates) based on the OECD pressure-state-response model of state of the environment reporting. The review also reports on environmental indicators used to assess the state of Australian inland waters in relation to the impacts of displaced/introduced fauna. The two types of indicators discussed and used are direct/primary indicators and indirect/surrogate indicators. Direct indicators are those which show the physical, chemical, biological and ecological effects of introduced/displaced fauna. Indirect indicators provide information about activities or conditions which are likely to result in impacts, for example, rates of introduction of exotic/displaced fauna, and the geographic range and abundance of particular species. The review covers seven families and 18 species of introduced fish, displaced/introduced invertebrates (particularly Crustacea and gastropod Mollusca), translocation, and diseases of introduced fish and invertebrates. Effects due to displaced/introduced fauna include:

• physical and chemical impacts on inland waters, such as alteration or degradation of habitat and water quality;
• biological impacts on indigenous/endemic fauna, such as hybridisation or alterations to the genetic structure of populations, and disease transference associated with introduced and displaced fauna; and
• ecological impacts on indigenous/endemic fauna, such as effects on reproduction and survival, abundance, population structure and species distributions, as well as disruption of aquatic communities, and effects on ecosystem processes. The response of society to problems of introduced and displaced species can be divided into biological conservation and management, catchment management, water conservation and management, as well as water quality and management. The greatest hindrance to management of the problems caused by exotic/translocated biota is the lack of information on the species concerned and their interactions with indigenous species and communities.