The question you raise here is whether they are an ETHICAL food. I guess, if you believe that oysters are sentient beings with a soul and it’s unethical to deny them their right to life, then no. However, if you don’t believe that but do want to eat in a way that minimises damage to the environment and pain to other animals then oysters seem to be a good choice. As you say, it’s a matter of individual conscience there.

I was going to mention that Peter Singer – who is a fiercely passionate advocate for animal rights and the vegan diet – has concluded that eating oysters is “probably OK”. But of course, being the expert you are, you already had that covered!

I recommend to readers the book The Ethics of What We Eat by Peter Singer and Jim Mason if they’re interested in the issue of ethical food. There is both an American and Australian edition. It’s fascinating and enlightening.