TRaCK: Tropical Rivers and Coastal Knowledge

Science and knowledge that governments, communities, industries for sustainable use of Australia's tropical rivers and estuaries

Systematic conservation planning of eastern Australian rivers to manage and maintain bioregional variation in fish biodiversity

TitleSystematic conservation planning of eastern Australian rivers to manage and maintain bioregional variation in fish biodiversity
Publication TypeConference Participation
Year of Publication2009
AuthorsKennard, MJ, Hermoso, V, Linke, S, Olden, JD, Pusey, BJ, Stein, JL
Keywords5: Foodwebs and biodiversity
Abstract

Systematic conservation plans aim to efficiently select a comprehensive and representative set of areas to ensure the long-term persistence of species. Plans that maintain bioregional integrity of species distributions may offer the best chance of conserving critical ecological and evolutionary processes. Unfortunately, these principles have not been applied to freshwater biodiversity conservation in Australia. Here, we use a simulated annealing algorithm (implemented using Marxan software) to identify and prioritise a minimum set of river basins to represent bioregional variation in the distribution of 109 native fish species across 230 coastal river basins in eastern Australia. We evaluated a number of planning scenarios in which the costs (i.e. management and restoration costs) of including particular basins in a reserve design were estimated according to basin area, intensity of human disturbances, or number of introduced fish species in each basin. Multivariate regression trees identified distinct freshwater bioregions comprising river basins that were strongly concordant (model R2 > 0.75) in terms of their environmental characteristics (e.g. hydrology, basin topography) and fish species composition. Systematic conservation planning analyses revealed that overall a relatively small number (~20%) of basins need to be managed to preserve bioregional integrity, but their identity varied according to the cost surrogate used. In contrast, 14 basins with high species endemism were consistently selected despite their high potential costs. Analysis of conservation priorities over the entire region yielded less costly reserve designs (i.e. fewer basins required) than plans that maintain bioregional integrity, but these may be less effective in maintaining longterm evolutionary potential and adaptive capacity of species. Our broad-scale analysis provides an essential spatial context to underpin more detailed conservation assessments within high priority basins and a foundation for developing freshwater fish management strategies in a region of Australia expected to undergo considerable future anthropogenic environmental change.

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