The (constantly-shifting) mouth of the Murray-Darling river system is also the Coorong’s mouth.
If the Murray is “roaring”, its “fresh” water “flushes” the Coorong – Australia’s longest lagoon; if it is not “roaring”, the combined forces of incoming ocean water and evaporation of the lagoon’s water make the Coorong progressively more saline.
The Coorong’s southern lagoon – a long way south of the Murray – is usually hypersaline.
This post’s photos were both taken from the Coorong’s northern part, looking at the Pullen Spit, and across it to the Southern Ocean.
In effect, the Pullen Spit is the northern bank of the Murray’s mouth.