If an area of water has been fished out, all or most of the fish in it have been caught.

There's no point going to an area that's fished out.

There used to be crabs here, but it must be fished out now.

The best fishing holes soon get fished out.

They started encroaching on other areas once their own waters were fished out.

The tribe's traditional waterways had become fished out.

See also: fish verb (ANIMAL)