Popular instruments in the field, optical backscatter instruments (OBS) are used to measure suspended sediments. The sensitivity of OBS measurements in relation to grain size and the applicability of OBS measurements in mixed sediment environments is analysed.
Dredging activities often result in the suspension of sediment into the water column in the vicinity of the activity. Sediment release to the aquatic environment and the effects of this release are often the prime environmental concern associated with dredging.
Maintenance dredging is required in many estuaries worldwide to provide access to ports and inland waterways. A newly developed dredging module is able to capture the two fundamental processes necessary to model the long-term impacts of dredging on turbidity.
Dredging for a new port complex in a remarkable, protected marine environment required adherence to very specific thresholds and an intensive Environmental Management Plan (EMP) that included mobile monitoring as well as daily visual observations of turbidity levels around the dredging works and the disposal zone.