“It appears that Blue Lake has been an important climate ‘refuge’ for the freshwater biota of the region, and is in the same condition now as it was 7500 years ago. With appropriate management, the lake could continue relatively unchanged for hundreds, possibly thousands of years to come,” Dr Barr says.Project leader and co-author Dr John Tibby, also from the University of Adelaide, says the results of this research could affect decision making about utilising the freshwater aquifer of North Stradbroke Island as a source of fresh water for the mainland.
“Our study suggests that increased extraction of ground water represents one of the few obvious threats to the stability of Blue Lake. The threat this could pose to the lake’s status as a stable freshwater refuge needs serious consideration if the regional aquifer of North Stradbroke Island is to be contemplated,” Dr Tibby says.
Why is this location important?
Like other important sand mass systems in south-east Queensland, North Stradbroke Island contains significant groundwater resources which are accessed by local communities and mining companies. In addition, a significant volume of groundwater is exported to the mainland. While there is the potential for expanded groundwater use, so little is known about groundwater-dependent water bodies and ecosystems that expansion is suspended. Dependent ecosystems include freshwater and estuarine wetlands, mangrove and paperbark communities, and surface-water fauna. There is evidence that vegetation communities have been changing response to changing groundwater conditions. Several species are listed nationally as endangered and a number are endemic to the island.