Ask A Scientist: Why Are Salmon And Trout Pink?

Pay a visit to your local grocery store, and the seafood section is a virtual sea of white, with two notable exceptions: salmon and trout. These tasty fish boast a rich hue of pinkish orange. So what makes these two fish so special that they have these eye-popping colours?

Biologist Jóhannes Sturlaugsson has devoted his life to studying fish, so naturally we asked him.

“The flesh is pink because of the food they eat. The pinker the flesh is, this usually means they are eating more crustaceans. More than half of the salmon’s food in the sea is pelagic crustaceans. This also applies in rivers and lakes, where insects they eat also give them this colour. Salmon and trout that have a diet comprised mostly of fish tend to have less colourful flesh.”

Incidentally, this is the same reason why flamingos are pink. These birds are actually born with grey feathers, which turn gradually pink on account of canthaxanthin in their diet of brine shrimp. Unfortunately, there are no flamingos in Iceland, but you can at least witness the magic of canthaxanthin in Iceland’s grocery stores and restaurants, each time you purchase salmon and trout.