Recession
From Beachapedia

Blockhauss of Capbreton (Landes, France) seen from the south. Built at the top of the dunes circa 1943, they are now underwater 2/3 of the time. It shows 200 meters of recession of the beach in 65 years.
Landward movement of the shoreline due to the loss of beach material and/or direct inundation of the land.