Flocculation
Flocculation in coastal waterways is a process in which particles of clay and organic matter stick together, through chemical interactions with divalent calcium and magnesium ions, to form larger flake-like particles (flocs or floccules) that may come out of solution. Flocculation influences the transport of fine-grained sediment, and enhances its deposition rate [1]. Because particles belonging to various size classes can form flocs, the sediment that is deposited is often poorly sorted [2]. Flocculation contributes to the formation of a turbidity maximum in coastal waterways (Figure 1), and can also cause patches of nutrients to form on the seabed, providing food for micro-organisms.
Figure 1. Conceptual illustration of the flocculation process (modified from illustration in [4])
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- Webster, I.T., Ford, P.W., Robson, B., Margvelashvili, N., and Parslow, J.S. 2003. Conceptual Models of the Hydrodynamics, Fine-Sediment Dynamics, Biogeochemistry, and Primary Production in the Fitzroy Estuary. Cooperative Research Centre for Coastal Zone, Estuary & Waterway Management Technical Report #8.
