'Biohyets': a method for displaying the extent and severity of environmental impacts

Bioindicators are often more sensitive indicators of both biodiversity and environmental change than abiotic pollution parameters. The responses of selected plants and animals to anthropogenic insults can be used to assess environmental responses at a variety of spatial and temporal scales. This study maps the response of key reptile, mammal, bird and plant species to airborne contaminants around a large mine and mineral processing operation at Olympic Dam in arid Australia. The responses of different bioindicators should ideally be integrated in order to comprehend overall trends in biological integrity adjacent to pollution sources. Assimilation of different bioindicator responses allows greater precision and geographic coverage of the monitored region and reduces potential distortion from unrelated biological or monitoring responses of individual indicator groups. A single, integrated measure of ecosystem health that overlays the responses of otherwise incompatible datasets, is also of more value to industrial operators and environmental regulators than several disparate responses. Biohyets, which are the contours of bioindicator index values derived from multiple biotic measurements, are here used to map variability in ecosystem health and to identify regions, response variables and disturbance parameters for more rigorous analysis.