There is an extremely complex system of tides and currents. Both the Bight and the Sound are essentially marine bodies with tides and saltwater, but the Sound compared to the Atlantic is about 20-30% less saline (as an estuary), and the tide is about 3 hours later with as much as 70% more variation. Rivers add a fresher, non-tidal inflow although the tide and brackishness extend well up rivers The United States Army Corps of Engineers (USACE) coordinates the projects. In 2016 the USACE and the Port Authority of New York and New Jersey produced a comprehensive restoration plan for the harbour region, which included proposals to mitigate the effects of sea level rise through projects to restore natural areas.