While unconsolidated sediments are the most common habitat in estuaries, several habitats are key to the high productivity characteristic of an estuary. These habitat types include mangroves, saltmarshes, oyster reefs, and seagrass beds. All habitats support estuarine biodiversity and provide many organisms with nursery grounds, feeding areas, and tidal and predator protection. Some habitats such as mangroves anchor the sediment to help prevent sediment erosion and displacement.