High bio-productivity ecosystems are distributed mainly along such near-shore waters, although they are many times smaller than those found offshore. They include, inter alia, tidal marshes, mangrove forests, estuaries, lagoons, small bays, coral reefs, deltas, sand beaches, islands, tidal mudflats, upwellings, soft and hard seabeds, and brackish aquacultural ponds. They have varying structures and functions, such as climate regulation, but are vital habitats and breeding grounds for thousands of marine species and waterfowl.