jp747 said..does this happen often at this place during the dry season? that's ruthless

Jimbob will be able to tell you with more authority, but my impression is this is the first time.
Previously the water level and salinity has been managed to help fish breed in there.
There's freshwater inputs and an ocean channel. But as Jimbob says the ocean channel is full of sand, and the freshwater was diverted to other lakes further west.
A great shame, this was one of the Australian premier GTC venues, maybe not the fastest in Australia, but all other divisions are possible.
Many sailors have several of their PBs here.