marco
A shallow place in a river is called a ford if it is used as a place to wade across to the other side. A shallow place can also be called a sandbar if the water does not cover all of the sand in a river or stream.
swamp
Shallow parts of the sea or ocean are called shoals or shallows. They are areas where the water depth is relatively shallow, making them potentially hazardous for navigation.
A shallow body of water that is separated from the open sea is called a lagoon. Lagoons are also commonly referred to as back reefs.
It's called SILT
riffle
creeks
swamp
Continental Shelf
A 'ford' which is a place where a river or other body of water is shallow enough to be crossed by wading.
A pool of shallow water connected to the sea is called a tide pool. There are some fish which live here and are known as offshore fish.
Lagoon