Time capsules of biodiversity: Future research directions for groundwater-dependent ecosystems of the Great Artesian Basin

Abstract

The Great Artesian Basin of Australia represents one of the largest and deepest basins of freshwater on Earth. Thousands of springs fed by the Basin are scattered across Australia’s arid zone, often representing the sole sources of freshwater for thousands of kilometers. As “islands” in the desert, the springs support endemic fauna and flora that have undergone millions of years of evolution in almost total isolation. Here, we review the current body of knowledge surrounding Great Artesian Basin springs and their significance from ecological, evolutionary, and cultural perspectives using South Australian spring wetlands as a case study. We begin by identifying the status of these springs as critical sources of groundwater, the unique biodiversity they support, and their cultural significance to the Arabana people as Traditional Custodians of the land. We then summarize known threats to the springs and their biota, both exogenous and endogenous, and the potential impacts of such processes. Finally, considering the status of these at-risk habitats as time capsules of biodiversity, we discuss lessons that can be learnt from current conservation and management practices in South Australia. We propose key recommendations for improved biodiversity assessment and monitoring of Great Artesian Basin springs nationwide, including 1) enhanced legal protections for spring biota; 2) increased taxonomic funding and capacity; 3) improved biodiversity monitoring methods, and 4) opportunities for reciprocal knowledge-sharing with Aboriginal peoples when conducting biodiversity research.

A comprehensive review of South Australia’s Great Artesian Basin spring and discharge wetlands biota

“…All raw data associated with this paper are available via FigShare (Beasley-Hall et al, 2023a, 2023b. Tables Table 1: Records of likely local extinctions of fauna in the SA GAB springs.…”

“…Springs fed by the Great Artesian Basin are no exception and are, generally speaking, considerably threatened by a range of industrial and pastoral practices (Mudd, 2000; Fairfax & Fensham, 2002; Lewis & Harris, 2020). Substantial reductions in artesian pressure (hereafter drawdown) and spring flow have occurred as a result of the sinking of over 50,000 artificial boreholes and the direct abstraction of Basin water, both historically and in the present day (Mudd, 2000; Gotch et al, 2016; Great Artesian Basin Coordinating Committee, 2019; Beasley-Hall et al, 2023). Indeed, a complete cessation of flow has occurred for an estimated 800 springs across Australia (Andersen et al, 2016; Fensham et al, 2016).…”

“…The sinking of more than 50,000 artificial boreholes and the direct abstraction of Basin water have led to substantial reductions in artesian pressure (hereafter drawdown) and spring flow (Beasley-Hall et al, 2023c;Gotch et al, 2016;Great Artesian Basin Coordinating Committee, 2019;Mudd, 2000).…”

“…Springs fed by the GAB are no exception and are considerably threatened by a range of industrial and pastoral practices (Fairfax and Fensham, 2002; Lewis and Harris, 2020; Mudd, 2000). The sinking of more than 50,000 artificial boreholes and the direct abstraction of Basin water have led to substantial reductions in artesian pressure (hereafter drawdown ) and spring flow (Beasley-Hall et al, 2023c; Gotch et al, 2016; Great Artesian Basin Coordinating Committee, 2019; Mudd, 2000). A complete cessation of flow has occurred for an estimated 800 springs across Australia (Andersen et al, 2016; Fensham et al, 2016), and declines of endemic fauna have been documented as a result of this degradation of spring habitats (Fensham et al, 2010).…”

Mediterranean springs: Keystone ecosystems and biodiversity refugia threatened by global change

“…4) can help to close this gap.6 | CON CLUS IONSSpring ecosystems are interface habitats between subterranean and surface freshwater environments, and they harbor unique biodiversity favored by both surface and groundwater organism populations providing important ecological functions. However, they probably constitute one of the rarest, most fragile ecosystems threatened by the effects of global change and the overexploitation of water, which might impair their capability to function as "time capsules of biodiversity"(Beasley-Hall et al, 2023). This is particularly critical for Mediterranean springs where the combination of natural (drying) and anthropogenic disturbances jeopardize their biodiversity and the ecological functions and ecosystem services they provide.…”