Esnandes is with Charron the key farming area of first class mussels. It was terribly damaged by the Xynthia storm of 2010 that destroyed most of the typical ‘carrelets’, the fishing structures you’ll see here. They’re all gone now. Some have been rebuilt but it’s not really like before.
The Ile de Ré is indeed a very touristic place although I never undertstood why actually. It’s just a boring, expensive & flat island to spend time on. Except for St Martin en Ré, the main city, there’s not much to see.