Complex sentence: Important activities are also underway to redress pollution in the industrial area of Porto Marghera, at the edge of the central lagoon: islands formerly used as dumps are being secured, the industrial canals are being consolidated and sealed, and polluted sediments are being removed.
Split into simpler sentences: Important activities are also underway to redress pollution in the industrial area of Porto Marghera, at the edge of the central lagoon. Islands formerly used as dumps are being secured; the industrial canals are being consolidated and sealed; and polluted sediments are being removed.