What is an estuary area rich in plant and animal life that forms?

The area you're describing is a mangrove forest.

Here's why:

* Estuary: Mangrove forests are found in estuaries, which are areas where freshwater rivers meet the saltwater ocean. This mixing of waters creates a unique environment.

* Rich in plant and animal life: Mangroves are highly productive ecosystems that support a vast array of plant and animal life. They provide shelter, breeding grounds, and food sources for countless species.

* Forms: Mangrove forests form in intertidal zones, areas that are alternately submerged and exposed by the tides. The mangrove trees are specially adapted to survive in these salty, oxygen-poor conditions.

In addition to mangrove forests, other areas that are rich in plant and animal life and form in estuaries include:

* Salt marshes: These are coastal wetlands dominated by grasses and other salt-tolerant plants.

* Seagrass meadows: These underwater meadows provide habitat for many marine creatures.

Let me know if you'd like more information about any of these ecosystems!