A threatened bird faces possible extinction if the health of the Murray-Darling Basin does not improve, animal groups say.
The Fairy Tern relies on a healthy Coorong for food and safe nesting but that is threatened by poor water management in the basin, Birds SA President John Gitsham says.
"We need to protect our natural environment and preserve our bird life, but the state and federal governments are ignoring science, putting commercial interests ahead of our unique and threatened species," Mr Gitsham said, as supporters gathered on Thursday in Adelaide to demand action.
The Fairy Tern is listed as a vulnerable species with a recent study recording an 82 per cent decline in the bird's population between 1985 and 2010.
"This is an urgent issue, the Fairy Tern is a gorgeous bird, beloved in South Australia," Mr Gitsham said.
The bird has a white body with light bluish wings and is native to Australia and New Zealand.
