Monitoring wave-induced sediment resuspension

The objective of this paper is to quantify resuspension and bed load transport of bottom sediments, induced by fast ferry wakes and wind waves near Aegna jetty, Tallinn Bay, using in situ measurements of waves, resuspension and optical properties of sea water. A new autonomous experimental set of two PAR-sensors, anchored into the sea bed, was used to measure the underwater irradiation. Wakes usually caused a rapid increase of the optical density of sea water by up to 50% from its background value. The total impact of fast ferry waves in terms of resuspended sediment concentration has not been substantially reduced compared to measurements in the past. However, wind waves apparently are the main driving force for both sediment resuspension and transport in 3 m deep water.