Cohesive sediments
Cohesive sediment, or mud, is a mixture of clay particles, silt, (fine) sand, organic material, and water. It preferentially settles in low-energy environments such as sheltered coastlines, estuaries and harbours. Mud deposits give rise to highly bio-diverse and therefore ecologically valuable systems such as mud flats, mangroves and salt marshes. These ecosystems are not only ecologically important, but also play a role in coastal defenses. At the same time, sedimentation in navigation channels and harbour ports is an obvious negative aspect. A better understanding of mud transport and deposition is therefore important for ecologic, safety, and economic reasons.
Suspended mud particles influence the water quality, usually in a negative way. Mud particles reduce penetration of light in the water column, leading to reduced photosynthesis or primary production. In extreme cases, high mud suspensions may influence vertical mixing rates, resulting in anoxic conditions and thereby high mortality rates. Toxic contaminant may adhere to mud particles, influencing the fate and residence time of particles. On the other hand, a certain amount of mud in suspension may also limit the growth of algae in a positive way because it may prevent harmful algae blooms.


