The Coorong (Kurrangk), located at the terminus of the River Murray, is recognised under the Ramsar Convention as a Wetland of International Importance. The aquatic macrophyte community of the Coorong comprised of Ruppia tuberosa, Ruppia megacarpa, Althenia cylindrocarpa and other Ruppia spp. (collectively, the ‘Ruppia Community’), are the foundational primary producers of the system. Together these species underpin ecological function through the provision of habitat for fish and invertebrates, trophic resources for waterbirds, nutrient sequestration, sediment stabilisation and oxygenation, and water quality improvement.
During the Millennium Drought (2001–2010), prolonged periods of insufficient freshwater flows resulted in hypersaline and hypereutrophic conditions that severely disrupted the life cycle of the Ruppia Community. These conditions caused widespread depletion of seed banks and extensive declines in distribution and abundance, particularly in the southern Coorong.
Since 2021, intensive monitoring of the Ruppia Community and associated environmental variables has been undertaken across the Coorong. Monthly in situ observations have documented the chronology and extent of key life history stages over six years, encompassing a broad range of seasonal conditions including ecological responses to the third largest flood on record in the lower Murray (2022–2023).
Variation in water availability and salinity drives shifts in the life history strategies of the Ruppia Community. Characterising these relationships is essential for understanding the distribution, abundance and resilience of the Ruppia Community, and its response to future hydrological variability.