Freshwater reserves in Australia: directions and challenges for the development of a comprehensive, adequate and representative system of protected areas James A. Fitzsimons 1, * & Hugh A. Robertson 2 1 Biogeographical Planning & Research Group, School of Ecology & Environment, Deakin University, 221 Burwood Highway, Burwood, VIC 3125, Australia 2 Current address: Riverland Local Action Planning Committees, PO Box 427, Berri, SA 5343, Australia (*Author for correspondence: E-mail: fitzsimo@deakin.edu.au) Key words: reservation status, reserve design, wetlands, ecosystem classification, conservation, freshwater protected areas Abstract The establishment of a system of protected areas that samples all ecosystems, including freshwater envi- ronments, in a comprehensive, adequate and representative (CAR) manner is regarded as a cornerstone for the conservation of biodiversity. There have been few quantitative assessments of the comprehensiveness, adequacy and representativeness of freshwater reserves in Australia. This paper reviews and quantifies the effect of classification of freshwater ecosystems for conservation planning, the importance of reservation status and protection measures for developing a CAR reserve system, and aspects of reserve design for freshwater ecosystems. We propose a strategic and iterative process that incorporates these measures to assist in the efficient and effective development of freshwater reserve systems worldwide. However, the provision of suitable water regimes for freshwater reserves presents further ecological and political chal- lenges, and even adequate reservation of freshwater ecosystems may not conserve constituent biodiversity without effective management. Introduction Freshwater ecosystems are recognised to be among the most threatened ecosystems in the world (Dugan, 1990; Abell, 2002; Saunders et al., 2002). The term ‘freshwater ecosystems’ for the purposes of this paper encompasses all inland aquatic eco- systems including rivers, wetlands, and ground- water systems as well as saline waters. An increasing human demand for supplies of fresh water, arable land and other natural resources is predicted (Baron et al., 2002). Consequently, the conservation of rivers, wetlands, estuaries, and other surface and groundwater ecosystems is a major challenge (Dugan, 1990). Anthropogenic pressures including river regulation, the develop- ment of agriculture, declining water quality, iso- lation from catchment processes, and degradation of riparian areas are continuing threats to fresh- water ecosystems in Australia (Walker, 1985; Boulton & Brock, 1999; Kingsford, 2000; Boulton et al., 2003). As for other ecosystem types, there is a range of mechanisms available for the protection and conservation of freshwater environments, including reservation, incentives for private land conservation, restoration, and other management actions. This paper focuses on one of these ap- proaches: the development of freshwater reserve systems to conserve biodiversity in these environ- ments. Internationally, the establishment of a com- prehensive, adequate, and representative (CAR) reserve system is a cornerstone for the conserva- tion of many terrestrial and aquatic ecosystems. These three objectives are defined by NRMMC (2005) where ‘comprehensive’ refers to inclusion of Hydrobiologia (2005) 552:87–97 Ó Springer 2005 D. Ryder, A. Boulton & P. De Deckker (eds), Conservation and Management of Australia’s Water Resources: 20/20 Vision or Blind Faith – A Tribute to the late Bill Williams DOI 10.1007/s10750-005-1507-4