Estuaries are unique and productive ecosystems where freshwater from rivers and saltwater from the ocean mix. They provide a diverse range of habitats that support various plant and animal species. Here are the major zones typically found in estuarine habitats:

1. Intertidal Zone: This zone is located between the high and low tide marks. It experiences regular tidal fluctuations, and organisms here are adapted to withstand exposure to air during low tide and submersion during high tide.
2. Subtidal Zone: This zone is submerged under water at all times and is influenced by tidal currents. It may include channels, deeper areas, and submerged vegetation. Many fish species and bottom-dwelling organisms inhabit this zone.
3. Salt Marshes: Salt marshes are found in areas of low wave action and are dominated by salt-tolerant grasses and other herbaceous plants. They provide critical habitat for a variety of birds, fish, and invertebrates. Salt marshes act as buffers, filtering pollutants and protecting coastlines from erosion.
4. Mangrove Forests: Mangroves are trees and shrubs that thrive in the intertidal zones of estuaries. They have unique adaptations to survive in saltwater environments and provide important nursery habitats for juvenile fish, nesting sites for birds, and protection against coastal erosion.
5. Mudflats: Mudflats are areas of fine sediment that are exposed during low tide. They are characterized by soft, muddy substrates and are often rich in organic matter. Mudflats support a diverse community of burrowing organisms, including worms, clams, and small crustaceans.
6. Seagrass Beds: Seagrass beds are submerged underwater and consist of dense meadows of seagrasses. They provide food and shelter for a variety of organisms, including fish, turtles, and invertebrates. Seagrass beds also help stabilize sediments and improve water quality.
7. Estuarine Channels: These are the deeper, narrow channels within estuaries that are influenced by tidal currents. They provide important pathways for water circulation, nutrient transport, and migration of fish and other aquatic organisms.

Each of these zones within estuarine habitats plays a crucial role in supporting biodiversity, providing nursery grounds for fish, filtering water, and offering protection for coastal areas. The specific composition and characteristics of estuarine zones may vary depending on factors such as tidal range, climate, and geographical location.