Diving into spring biodiversity: A natural heritage assessment of Australia's Great Artesian Basin discharge wetlands

Abstract The Great Artesian Basin (GAB) is Australia’s largest groundwater resource and feeds thousands of springs in the country’s arid centre. GAB springs are globally important “time capsules” that support relictual species not found elsewhere on Earth, yet they are considerably threatened by ongoing water abstraction for pastoral, agricultural, and industrial practices. Biomonitoring and robust management plans are needed to prevent further extirpations of GAB-dependent taxa, but there remains a paucity of biodiversity and ecological knowledge in the literature. We conducted a comprehensive review of GAB spring biota for South Australia, the state containing the majority of springs. Almost 500 taxa are recorded from GAB springs and surrounding wetlands. Invertebrates represent the largest proportion of GAB endemics and biota overall, yet they are highly threatened and have not received adequate conservation attention. Community composition differs considerably among spring clusters, highlighting their intrinsic value as refugia for both endemics and cosmopolitan taxa. Further, several potential biodiversity hotspots have been overlooked in the literature and the true extent of GAB spring biodiversity is likely far greater than currently known. Our findings underscore the importance of freshwater sources in arid regions and the need for fundamental research in the face of ongoing human impacts.