I now have a flock (yes a
flock) of black cormorants assaulting the dam so perhaps there are
some fish left. Will there be any tomorrow? We live in hope.

I've read that throwing old metal beds into dams is a good way of
protecting fish from cormoratns - apparently it gives the fish a
place to hide.

Nah. It just saves the place looking like a junkyard along with all the old
farm equipment, rusted cars and rolls of rusty wire.

D