Artificial seaweed fronded mattress comprises of lines of polyethylene fronds attached to a concrete mattress, concrete block, grout bag, etc. When installed on the seabed, the polyethylene fronds float in the water like natural seaweed which increases the drag resistance of the current passing through. This action reduces the nearbed flow velocity and encourages soil deposition onto the mattress. permanent sand bank reinforced by the polyethylene fronds is gradually formed on the mattress, providing scour protection against localized seabed erosion, and maintain the stability of the subsea structures.