At Shark Bay in WA, we swim at Little Lagoon just out of the town of Denham. It is one and a half times more salty than normal sea water and it is impossible to stay on the bottom. On a warm afternoon, we and others are bobbing about like corks.
Nearby Shell Beach is home to millions of tiny Fragum cockle shells. They say there are 4000 per square metre but how did they arrive at that figure did they weigh them or count them? The water here is twice as salty as normal sea water. Any more salt and you’d be able to walk on it. There is an electric fence that crosses the peninsula at this point to keep the park free from feral cats, goats and foxes.