Study reveals Baltic Sea impacts of ship wakes - Baltic Sea's Seabed Eroding as Ship Traffic Reshapes Underwater World

Ship traffic in the Baltic Sea is causing growing damage to the seabed and water layers. New studies reveal that large vessels create deep wakes, disrupting natural conditions far below the surface. Over time, these changes have reshaped parts of the seafloor and altered underwater ecosystems.

The movement of ships generates powerful wakes that stretch down to 12–16 metres. These forces break up the water's natural layers, changing how oxygen, nutrients, and dissolved metals move between deep and shallow zones. When the water mixes, it can stir up sediments laden with organic matter, pollutants, and nutrients long buried on the seabed.

The shear forces from passing vessels often exceed the limits that keep seabed sediments in place. As a result, small depressions form along shipping routes, sometimes affecting strips up to 60 metres wide. In the western Baltic, erosion from propeller wash has deepened fairways by 2–3 metres in key channels over recent decades.

Bathymetric surveys show the problem has worsened since the 1980s. Areas of severe seabed change have grown by 20–50% in depth, spreading from major ports like Kiel and Lübeck. Today, around 500 square kilometres of the seafloor show signs of traffic-related erosion.

The long-term effects of shipping are now visible across large sections of the Baltic's seabed. Fairways have deepened, sediment movement has increased, and the natural balance of the water column has shifted. These physical changes will continue to influence the region's underwater environment for years to come.