Definission: Seagrass beds are highly diverse and productive ecosystems, and can harbour hundreds of associated species from all phyla. They partly create their own habitat: the leaves slow down water-currents increasing sedimentation, and the seagrass roots and rhizomes stabilize the seabed.
Definission: Expressions of the estuarine biome occur at wide lower courses of a rivers where they flow into a sea. Estuaries experience tidal flows and their water is a changing mixture of fresh and salt.