An Overview on How Diet Affects the Color of Salmon’s Flesh

Have you ever heard that if you eat a bunch of carrots, you’ll turn orange? Salmon end up orange, pink or even red for the same exact reason: carotenoids.These mighty plant pigments have the power to brighten flesh. And that they do. But the how depends on whether the salmon is wild or farmed.

Wild Salmon Gets Its Color From Its Diet

In the wild, salmon get their characteristic hue from the creatures they eat. Even as eggs, salmon are a shade of pink or orangish red. The unique color reflects this carnivore’s diet of shrimp and krill. Each species of salmon eats a different proportion of these carotenoid-rich crustaceans, which influences how pink or red they become. For example, sockeye and coho salmon tend to be the deepest in color, while pink salmon is, well, pinker.

Then there’s the special case of king salmon, which can carry a recessive trait that leads to white or ivory flesh. In the past, fishermen and women used to stay away from this oddity, but white-fleshed, wild-caught king salmon is now considered more of a delicacy. Now, does it taste the same as its more colorful counterpart? That’s up for debate.

Moving out of the wild and into the pens, farmed salmon is generally on the pinker side, also because of its diet, but not for the reasons you might expect.

How and Why Farmed Salmon Ends Up Pink

Typically raised in feedlots, farmed salmon don’t have access to the wild shrimp and krill that wild salmon eat. Instead, salmon farmers often use corn and soy pellets, as well as fish meal made from smaller species like mackerel to feed their salmon. And then there are other farms, which now use feed made out of insects (1). Without shrimp or krill, farmed salmon don’t consume naturally-occurring carotenoids. And no carotenoids would lead to greyish flesh -- not pink or red. So what’s the catch?

Well, many farmers end up adding synthetic astaxanthin, a naturally occurring compound in carotenoids, to their feed in order to achieve that pink color, so their farmed salmon better resembles wild-caught. Why bother taking this extra, costly step? Because it sells.

According to research conducted by DSM, a company that supplies dye to salmon farmers, different intensities of salmon dye appeal to different consumer bases. DSM even offers a “SalmoFan” to their clients — kind of like a paint wheel — to help salmon farmers determine how much pigment to use in their fish feed in order to achieve a certain shade of pink (2). Industry research conducted by a group of Norwegian academics shows that when offered the choice, consumers associate quality with color and would be willing to pay more for richer shades of pink (3).

If you’re curious, here are some tips on how to spot wild salmon vs. farmed because seafood fraud in the U.S. is real.

Salmon Are What They Eat

So there you have it. Farmed or wild, a salmon’s color resembles what it eats. Shrimp and krill for wild and synthetic astaxanthin for farmed.

If you're ready to buy some of the best wild-caught, sustainably harvested salmon on the planet, click here!