Great Blue Heron walking through an old rice field.

At one point this marsh pond was part of a rice plantation, pre civil war.

The fresh water is fed by an old trunk skimming a salt marsh. The genius of the thousand year old West African system is a wooden gate is just shifted slightly.  Fresh water, the top of the salt marsh water, flows into marshes and ponds leaving the salt behind.

Wading birds, and Alligators, want fresh, not salt water. Of course rice also grows in fresh water.