mark of certification from the Forest Stewardship Council (FSC), and if you don't see one, press the retailer for more details. The National Resources Defense Council (NRDC) is a good source for information about tropical and other woods for which sustainability tends to be an issue.
those at a gift bazaar in Miami. Here is an interior design resource in Walton County, Florida that specializes in shells and shell interior decor. I'm sure the owner can probably find these for you. http://www.nuanceliving.com/