Australia's coastline is characterised by intense habitation, use, and exploitation, the combination of which have posed many serious threats to the integrity of our extremely diverse marine and estuarine environments (Fairweather, 1990; McNeill, 1994). Because of Australia's extreme marine biodiversity, a conventional systematic means of classifying biogeographic regions for the purposes of ensuring that a national network of MPAs will be representative (such as that employed by IUCN in regionalising the South Pacific) may not be effective in this country (Kenchington and Bleakley, 1994; McNeill, 1994). It seems likely that a more comprehensive and data-based regionalisation of the Australian EEZ must be attempted.
As in most endeavours of this kind, the greatest hurdle to the development of such a strategy is the absence of information (McNeill, 1994). Fairweather and McNeill (1993) suggested that a complete inventory of Australia's coastal resources, incorporating oceanographic, geomorphic, ecological and genetic data, along with information about ecosystems, habitats and species, would be necessary before a truly scientifically credible selection of representative MPAs could be made. Clearly, this suggestion is impractical in the current (or indeed in any foreseeable) economic and environmental climate. A compromise must be made which balances the demands of a relatively small budget and the need for scientifically robust biodiversity data and analysis to achieve an ecologically relevant regionalisation of Australia that is useful to decision-makers.
The biogeography of Australia has a distinguished history, from Hedley's (1926) early work on zoogeography, refinements by Whitley (1932) to Bennett and Pope's (1960) classic biogeographic regionalisation and the more modern treatment of Wilson and Allen (1987) using benthic infauna data for inshore species.
Bennett and Pope (1960) distinguished two tropical provinces and three temperate provinces with an overlap of warm and cool temperate provinces occurring in the south-eastern Australian region encompassing Bass Strait and Tasmania. Wilson and Allen (1987) however did not find evidence to support the concept of a cool temperate province.
Knox (1963) classified Australian littoral zones into biogeographical provinces on the basis of physical and selected biological characteristics. He concluded that seven major provinces existed around the Australian coastline, with boundaries occurring in the vicinity of the Houtman Abrolhos Islands, in Torres Strait, at around 25oS on the Queensland coast, between Albany and Esperance in Western Australia, Robe in South Australia, and at an indeterminate location on the southern NSW - eastern Victorian coast. Bennett and Pope (1959) found that the littoral areas of Tasmania and southern Victoria together comprised a bioregion clearly separate from that of the rest of Australia. However, Wilson and Gillett (1971) on the basis of gastropod shell zoogeography proposed that there were only two real marine biogeographic zones in Australia, a northern tropical and a southern temperate region, with a broad overlap area in between.
In a driftnet catch-based study of pelagic fish of the south Pacific Ocean, Yatsu (1995) found that catch species composition could define subtropical, transitional and subantarctic regions. The transitional region, which Yatsu (1995) described as "an ecotone for nekton", occurred at around 40oS, though this position was strongly affected by seasonal migrations of epipelagic fishes.
In 1985 a national regionalisation based on Ray's (1976) work was adopted by a Council of Nature Conservation Ministers (CONCOM) - the so-called CONCOM regionalisation. The failure of the CONCOM regionalisation, in the decade or more of its existence, to substantially meet the needs of conservation agencies has resulted in the present effort. Whilst a consensus assessment of why CONCOM failed is not available, it is generally acknowledged that it is due to the disparity in the spatial scales of CONCOM and those of interest to managers of MPAs, and secondly, to the lack of scientific basis of the chosen CONCOM regions (Thackway, 1995).
The Bioregionalisation Project has attempted a scientifically credible bioregionalisation of Australia's marine environments. It aims to produce bioregions which are ecologically meaningful, at a scale useful for managers and planners, and which are comparable across the EEZ. By using a variety of biotic and abiotic features and by trialing a number of analysis techniques, the project also hopes to provide a framework for future and sorely-needed research into our marine environments.
Next Chapter: 8. Regionalisation Methodology