Port entrances and their deepened channels form an artificial element in a natural coastline. Sediment flows, habitats, marine life is influenced through construction and existence of hard elements and can affect coastal systems tens of miles away from the port itself. Aside from the physical changes, dredging and construction itself also cause a variety of negative effects; dumping ground for dredged materials burying sea life, suspended particles due to dredging, noise from marine construction works. Shipping activity brings several other concerns ranging from oil spills, dumping of waste, dissolving anti-fouling coatings, toxic emissions from the engines and mixing of ecosystems through release of ballast water. This is a selection of effects, but the range is diverse and impact is severe.