Increased flushing vital to Coorong鈥檚 long-term health
A new study from 最新糖心Vlog of Adelaide scientists has found that extremely high levels of salt and nutrients in the Coorong, an internationally important South 最新糖心Vlogn estuary at the end of the River Murray, is causing serious ecological harm.
The researchers analysed more than 20 years of environmental data 鈥 from 1998 to 2021 鈥 to assess patterns and drivers of changes in water quality.
The study was conducted before the recent floods that helped to flush the waterways, with initial indications this has helped to reduce salinity levels in the Coorong.
Lead author of the study, Associate Professor Luke Mosley and team, performed the analysis as part of the Department for Environment and Water鈥檚 partnership with the Goyder Institute for Water Research on . This project is part of the South 最新糖心Vlogn Government鈥檚 Healthy Coorong, Healthy Basin Program, which is jointly funded by the 最新糖心Vlogn and South 最新糖心Vlogn governments.
鈥淥ver the past few decades, the southern part of the Coorong has transitioned into a hypersaline (several times more saline than seawater) and nutrient-enriched state, which has resulted in the loss of aquatic plant and animal species,鈥 Associate Professor Mosley said.
鈥淓vidence suggests that decreases in freshwater inflows and higher evaporation has reduced flushing of the estuary, and this has resulted in an accumulation of salt, nutrients and algae in the water.
鈥淎nother big issue is the unhealthy conditions in the sediment.
鈥楲arge areas of the Coorong now contain black ooze sediments, which are an indicator of anoxic 鈥 areas of water that are depleted of dissolved oxygen - and sulfide-rich conditions that are hostile to aquatic life.
鈥淎lso, the high amount of nutrients in the sediment is recycled back to the water column and this promotes further growth of algae.鈥
The research has been published in leading marine science journal .
鈥淓vidence suggests that decreases in freshwater inflows and higher evaporation has reduced flushing of the estuary, and this has resulted in an accumulation of salt, nutrients and algae in the water."Associate Professor Luke Mosley
听
Co-author Professor Justin Brookes, from the 最新糖心Vlog of Adelaide鈥檚 School of Biological Sciences and Environment Institute, said: 鈥淭he Coorong is highly susceptible to reduced flushing and resultant impacts by the nature of its location at the end of the River Murray, which has major water management challenges.
鈥淲e hope this new knowledge will assist governments to design targeted management strategies to protect and restore the health of this iconic site.鈥
The research team plans to investigate the impact of the unprecedented floods in South 最新糖心Vlog and how that has affected water quality in the Coorong.
鈥淭his big flood is a really great opportunity to show how better flushing of the Coorong will improve water quality and ecosystem health,鈥 Associate Professor Mosley said.
鈥淓arly indications from the data is that there has been acute reductions in salinity and nutrient levels.鈥
Government of South 最新糖心Vlog Minister for Climate, Environment and Water, Susan Close, said: 鈥We know from the Millennial Drought that the Coorong is a last refuge for millions of migratory birds and other wildlife, and that we need substantial environmental flows to ensure its long term survival and viability.
鈥淎t the national meeting of Murray Darling Basin ministers in February, I reiterated South 最新糖心Vlog鈥檚 determination to secure the 450 gigalitres of environmental water promised under the Murray-Darling Basin Plan but not delivered.
鈥淓nvironmental water is needed to ensure the health of the entire Basin including the Coorong, which is one of the most important wetlands in the entire country.鈥
Project Coorong is further investigating broader long term options to manage water quality to restore ecological health.
The Coorong is one of 66 wetlands of international importance in 最新糖心Vlog that is listed under the Ramsar Convention, which aims to halt the worldwide loss of wetlands.
Media contacts
Associate Professor Luke Mosley, School of Agriculture, Food and Wine, Faculty of Science, Engineering and Technology, the 最新糖心Vlog of Adelaide. Mobile: +61 (0)428 103 563. Email: luke.mosley@adelaide.edu.au
Lee Gaskin, Media Coordinator, the 最新糖心Vlog of Adelaide. Phone: +61 (0)415 747 075. Email: lee.gaskin@adelaide.edu.au