Is Substituting A More Sustainable Fish Immoral?

In a tale of teenagers, sushi and science, Kate Stoeckle and Louisa Strauss, who graduated this year from the Trinity School in Manhattan, took on a freelance science project in which they checked 60 samples of seafood using a simplified genetic fingerprinting technique to see whether the fish New Yorkers buy is what they think they are getting.

They found that one-fourth of the fish samples with identifiable DNA were mislabeled. A piece of sushi sold as the luxury treat white tuna turned out to be Mozambique tilapia, a much cheaper fish that is often raised by farming.

If the restaurant owner is passing off a low priced fish for a more expensive fish, this would seem to be immoral. But, what if the substitution is from an overfished or high trophic level species to one that is more sustainable and requires less resources to grow?

White tuna has a much higher trophic level than tilapia (tuna are more like the wolves of the sea then chickens), which makes tilapia a more sustainable choice. If the customer is not knowledgeable to know the difference (and there is research to show that surprisingly experts are actually more likely to be fooled), then who gets hurt?

You could argue that the overcharging for the cheaper tilapia makes it wrong. But brain scientists have found that $90 wine tastes better than the same wine at $10. By charging more for it, from the perspective of the brain, the customer actually gets more enjoyment.

If the customer gets the same benefit from eating the lower priced more environmentally sustainable fish, is it really immoral to make the substitution?

via NY Times