How can it look so good after that kind of journey? Much of the tilapia farmed in China is frozen and then treated with carbon monoxide, a gas that prevents meat and seafood from discoloring as it ages. When it is thawed, it looks like new.

Carbon monoxide-treated fish is safe to eat, but the treatment does deprive consumers of visual cues about the freshness and handling of the seafood they’re buying. And that could be especially important when the fish comes from China, where aquaculture is poorly regulated.

Read the complete blog from The New York Times.