Nearshore dredging in the Baltic Sea: Condition after cessation of activities and assessment of regeneration

Using hydro-acoustic survey techniques (side scan sonar and multibeam) high resolution bathymetric and acoustic images (sonographs) of former marine aggregate extractions from Tromper Wick (Rugen Island Baltic German Coast) were obtained These data together with ground truthing (underwater video and seabed sediment samples) are used to describe the present condition of marks generated by mining in terms of their morphology and superficial grain size distribution Different features (pits and furrows) generated by different extraction techniques (anchor suction dredging and trailer hopper suction dredging respectively) were detected at both of the study sites Tromper Wick I (sandy gravel seabed) and Tromper Wiek East (sandy seabed) Regeneration vanes depending upon the material extracted and the mining technique applied In general it is mind during the first years following the extraction becoming almost undetectable over a longer period of time However the marks ale still detectable after more than 10 year's since they were generated