That river has a tendency to flood during the times that we get some heavy rains.
If you look at that photo where those cypress trees fork, that is where the water has risen to many times in the past, and you'll notice tops of some of those trees broken off.
Stocking of the park annually with trout that will die as the water warms and those that aren't caught will get eaten by the birds, other than that everything else is native and fends for itself.
You need to hang out a while over in the Bluegill section with those guys!
They fish all the rivers and creeks in the area, and they have no problem "catching" rather than just practice casting.
They mostly use the Bait of Champions and catch a plethora of species!