Study reveals Baltic Sea impacts of ship wakes - How Shipping Traffic Is Reshaping the Baltic Sea's Hidden Ecosystem

Shipping traffic in the western Baltic Sea is causing unseen changes beneath the waves. Large vessels passing through busy routes are disturbing the seabed and altering the water's natural layers. The effects stretch far beyond the ships themselves, impacting both the seafloor and the water column.

The movement of big ships creates powerful wakes that disrupt the Baltic's delicate balance. These wakes can reach depths of 12 to 16 metres, breaking up the natural separation between surface and bottom waters. As a result, oxygen, nutrients, and trace elements mix in ways that do not occur naturally.

The force of ship propellers also stirs up the seabed. Shear stresses from passing vessels exceed the limits that keep sediments in place, carving small depressions into the ocean floor. Along a ship's route, this disturbance can affect strips of seabed up to 60 metres wide.

When sediments shift, they release trapped materials into the water. Organic matter, pollutants, and nutrients—once buried—become mobile again. Over time, this constant churning changes how the seabed and water interact, though long-term data on these shifts remains scarce.

The western Baltic's busy shipping lanes continue to reshape the underwater environment. Sediment erosion and water mixing alter conditions for marine life, while mobilised pollutants pose further risks. Without detailed records, the full extent of these changes over decades remains unclear.