This question made me wonder: how much mass (or volume) of material is eroded by the sea each year? Of this mass, how much is deposited in the oceans? (As Michael pointed out in his answer, part of the eroded material can be redeposited on another part of the shoreline.)
The bottom line is: I wonder if the increase in sea level (and subsequent increase in coastal erosion) could lead to a positive feedback because of Archimedes principle. I'd like to calculate if the volume of material deposited in the oceans is enough to make the sea level rise, or if this effect is negligible.