These are FISH BEDS.

Our cove is full of them. The bass come in and make these bed to lay their eggs.

And when they hatch, this is where the heron and turtles and larger fish come to eat all the small fry they can, and where the small fry that dont get eaten hide out and try to blend in until they get big enough to head out into the open lake.

But for most, this is where their lives begin and end.