By providing essential resources to replenish beaches, marine aggregates are a solution to coastal erosion rather than the cause of it. Such erosion is a natural process, driven by waves and currents that affect both beaches and cliffs.

One of the industry’s key objectives is to ensure that dredging does not affect such processes; for example by changing the wave climate or interfering with seabed sediment transport. Before permission to dredge is granted, careful analysis of waves and currents in the area is undertaken using hydrodynamic models.  Modelling is combined with an assessment of sediment transport to ensure that pathways to beaches or along the coastline are not disrupted.

Although dredging often occurs large distances offshore - eight kilometres or more - and commonly in water at least 20 metres deep, the industry still carries out detailed studies to determine the possible influence of dredging on natural processes. A conservative approach exaggerates the dredging and consequently over-estimates the possible impact. Permission would not be given if the experts felt there was the slightest threat.  As a further safety mechanism, monitoring of the seabed, and adjacent coast in sensitive areas, is also undertaken while dredging is carried out.

Ask an expert

You can get an expert view on the issue of whether dredging affects coastal erosion by watching a specially commissioned BMAPA video.

View video