I found this site that makes flip-flops out of rubber fish. Here's why it's a bad idea:
1. Seal attacks
2. Shark attacks
3. Jellyfish attacks (they don't eat fish, but you can't run from them in those things)
4. Whale attacks
5. They are ugly
Note that the appearance of the shoes only made nr 5 on my list. My ordinary beach shoes are pretty ugly, but I can run away from anything that wants to amputate my feet in them. Sometimes I think we should poison the ocean and get it over and done with.