As to tidepools and sandy beaches, California beaches build up naturally
when the waves are relatively gentle (summer) and erode when the waves are
rough (winter). Tidepools are better exposed during the winter. I suspect,
though, that Stephen MacMahan is describing a long-term trend in Oregon. If
so, that's intriguing.
 
Another relatively trash-free beach is Cumberland Island, Georgia, which
has already been mentioned a number of times on Conch-L. Cumberland Island
is a national seashore and has no bridge. Only a small number of people are
allowed on the island each day, so it is as close to pristine as you can
get on the US Atlantic seaboard.
 
I remember a series of articles in the Atoll Research Bulletin (60's or
70's), in which some researchers described one small rock after another in
the remoter parts of the Hawaiian chain. These islets had no inhabitants
other than birds, and no landings; it was hazardous just to be near them,
and some could only be studied from a distance. The scientists were trying
to describe all they could about islands that would probably not be studied
again for decades. Presumably they are pristine, and likely to remain so.
Any comments from our friends in Hawaii?
 
Andrew K. Rindsberg
Geological Survey of Alabama