Mudflats are sedimentary intertidal habitats created by deposition in low energy coastal environments, particularly estuaries and other sheltered areas. The sediments generally consist of silts and clays with a high organic content. Mudflats frequently occur as part of the natural sequence of habitats between the subtidal zone and vegetated salt marshes or mangroves. Like most other intertidal habitats they dissipate wave energy and thus have an important role reducing the risk of erosion and flooding in the coastal zone. The mud (including the microbial and macroinvertebrate fauna associated with it) plays an important role in nutrient cycling. Mudflats are typically highly productive habitats supporting a high biomass but relatively low species diversity. The nature of the biota reflects the prevalent physico-chemical conditions.
The surface of the sediments may appear devoid of vegetation however they are often covered with dense mats of microalgae. These make a significant contribution to the stability of the sediments as the mucilage that they produce helps to bind particles together. Mudflats are very important habitats that support large numbers of birds and fish. They provide both feeding and resting areas for important populations of waders and waterfowl and also function as nursery areas for flatfish. They support numerous species of clams, polychaete worms, amphipods, and other invertebrates. They are critical habitats for their specialized residents. They provide foraging grounds for shorebirds, ducks, fish, and marine invertebrate predators, as well as spawning and nursery habitats for forage fish and juvenile crustaceans.
