When I was a little girl I used to be able to walk on my home beach in Port Stanley Ontario on Lake Erie and find buckets full of wonderful treasurers, now I can barely find 5 pieces. It's true in the spring that I can find lots, but each year it is less and less. Between plastic products and the responsible behaviour of recycling (which is a good thing) finding glass is rare now.
Here's an article that someone from the Art Festival pointed me to from the National Geographic early this summer. the article is written by Margaret G. Zackowitz. A short but worth while read.