principal changes include modification and stabilisation of the inlets via the construction of long jetties and outer sea walls dredging of broader and deeper navigation channels to favour tanker cruise ship and container traffic land reclamation on marshy areas and fish farm development through the closing off of vast areas of the lagoon periphery to tidal excursion these modifications intensified during the latter part of the twentieth century to support the growth of industrial activities in the marghera area whose legacy left contaminants especially heavy metals and complex hydrocarbons in the various layers of lagoon sediment capodaglio et al human activities especially industrial production in marghera which extracted large volumes of groundwater have caused a further compaction of the soil