To arrest the attrition of biodiversity and other valued aspects of the natural world, we place much faith and hope in protected areas and other places managed for nature conservation (collectively “conservation areas”). If we look at where conservation areas are, across Australia and around the world, they tend to be concentrated in areas that have least value for extractive uses and, therefore, least need for protection (Pressey et al. 2000). This tendency for conservation areas to be residual to human requirements is reflected in conservation areas having one or more of these characteristics: infertile, rugged, arid, remote, poorly drained, high (and covered by ice or snow), disease prone, unsuitable for trawling, and unpromising for oil and gas exploration. Why is residual conservation a bad thing? The main reason is that the areas most in need of protection don’t get it, while the areas more prone to loss of their distinctive biodiversity and other natural values continue to languish. Related to this, each additional residual conservation area entails an irretrievable opportunity cost: loss elsewhere that could have been avoided but was not.
Common measures of the effectiveness of conservation areas hide the residual nature of conservation areas and wrongly infer that progress is being made. Measures of extent or percentages of regions covered by conservation areas are, in themselves, meaningless. They say nothing about how well conservation areas have achieved their role: to avoid the loss of natural values. Measures of representation are only slight improvements. An increase in representation of marine habitat types from 35 to 52 in an Australian marine bioregion is not necessarily an advance for conservation. Much depends on whether the additional 17 habitat types were the ones that most needed protection because they were most prone to depletion in the absence of conservation intervention.
More than 30 years ago, Jared Diamond (1976) wrote: “the question is not which refuge system contains more total species, but which contains more species that would be doomed to extinction in the absence of refuges”. Diamond was talking about the importance of distinguishing means from ends. Conservation areas are the means to the end of avoiding loss of biodiversity and other natural features. If we base our measures of conservation progress on means (conservation areas) and avoid measuring how well we have achieved our stated ends (avoided loss), there are few prospects for real conservation gains. Moreover, we will waste a great deal of money, skill and time on establishing conservation areas in places that are not real priorities for our limited resources. The way forward is to develop measures that reflect how well we have used conservation resources to avoid the loss of the things we purport to care about. Early steps have already been taken by researchers. Strong and rapid progress in practical, informative measures is possible, but only if the crucial importance of measuring avoided loss is accepted by policy-makers and used to guide further expansions of protected areas and other conservation actions.