Seawalls built to trap sand in the short term impair the natural seasonal
distribution of sand resulting, in the long run, in a net beach loss and in a
reduction of the island land mass.
* Boat channels blasted in the reef act as a sand trap; in time they fill with sand
which is no longer circulating around the island; in turn this sand is replaced by
other sand eroded from the vegetated edges, changing the size and shape of the
island and in time threatening the island’s integrity