Data collected since 1880 from shoreline sites generally show most of the loss of shoreline land along Long Island Sound occurring in areas where the geology is sandy – Norwalk to Milford and Guilford to Old Lyme. Barrier beaches tend to register the greatest losses. The huge long-term gain in New Haven and a smaller one in Bridgeport are the result of man-made development – the filling in of waterfront areas to increase land mass.

The short-term change, from 1983 to 2006, shows a far more pervasive loss of land.