Salmon color: What are the different colors of salmon?
Salmon is an extremely popular fish for eating, a central part of many different dishes from cuisines around the world. Salmon are known for their vibrant pink, orange, and red hues that can be easily recognized on grocery store shelves and in dishes such as sushi or poke. Yet the reality is that if your dinner consists of farm-raised salmon, that trademark color is likely fake — the result of synthetic additives intended to make the fish’s flesh more palatable to consumers.
What are the different colors of salmon?
The color of salmon scales differs based on species. Many salmon have some silver scales, and these are generally complemented with other colors. Sockeye salmon, for example, are silver with a blue tinge when they are living in the ocean, but when they return to their spawning grounds they turn a bright red and their heads turn green — leading them to also go by the name red salmon.
The raw truth, however, is that typically when we are discussing the color of salmon we do not mean the color of their scales but rather the color of their flesh once they’ve been slaughtered and sliced. This is in stark contrast to most other animals. When we discuss the color of a dog, or even other animals that we consume as food such as cattle, we tend to talk about the color they appear when alive and not the color of their flesh.
In discussions of the color of salmon flesh there are four colors you might hear: white, pink, orange, and red. The amount of carotenoids, most commonly astaxanthin, that an individual fish consumes is generally the determining factor for the color of the fish’s flesh, with darker fish typically being worth more to the average consumer.
The color that we are most familiar with when it comes to salmon flesh is pink. The pink hue results from astaxanthin. In the wild, salmon obtain astaxanthin as a normal part of their diet, which consists of shrimp and krill that in turn consume microalgae and phytoplankton. These organisms produce astaxanthin naturally.
You may have noted that the flesh of farmed salmon in the stores is also pink. The diet of these fish is devoid of naturally occurring astaxanthin, as they are most often fed a dry kibble consisting of smaller fish and a variety of ingredients, often byproducts of other food production processes. To achieve the pink hue, farmers feed their fish a version of astaxanthin that is created synthetically using petrochemicals, as an additive to the kibble.
Salmon that have an orange hue to their flesh have consumed a larger amount of astaxanthin than the fish that have pink flesh, but less than those that appear red when killed and cut. For wild fish, whether their flesh is pink, orange, or red in hue is determined by how much astaxanthin they have been able to catch or find to consume as part of their natural diet, but for farmed fish astaxanthin is an additive. The company DSM provides a tool called SalmoFan that tells farmers how much synthetic astaxanthin to add to the feed of the fish they are raising in order to accomplish the desired color. This gives farmers the ability to essentially build-a-fish according to their specifications and market demand.
A red hue to salmon flesh means that while alive the fish ate a large amount of astaxanthin. Because of the high cost of synthetic astaxanthin, this color is typically found in wild-caught salmon. Farmers are likely to feed the fish they are raising enough of the additive to reach a pink or even orange color, but not enough to reach a deep red.
Wild-caught sockeye salmon are the species of salmon that most frequently have a deep red hue to their flesh. The primary habitat of sockeye salmon is near the Bering Sea, which is home to a large number of astaxanthin-containing krill, which the fish consume as a dietary staple. Species of salmon that tend to live further south, such as king and coho, usually have flesh that is a less vibrant orange or pink.
Gray or white
The flesh of farm-raised salmon would be gray if it weren’t for the addition of what is effectively a dye, to give the steaks and other cuts of the fish a pink hue. In captivity, salmon are not fed the same food they would eat in the wild but rather are most commonly given a kibble composed of fish and oils from smaller fish, gluten, chicken fat, and a hodgepodge of other ingredients. The farmer is also likely to be including synthetic astaxanthin as an additive. Synthetic astaxanthin is chemically different from the naturally occurring type, and has the primary purpose of dyeing the salmon’s flesh. The additive is very expensive for farmers, constituting about 20% of the total cost of feeding the salmon they are raising. Because consumers are not likely to purchase salmon that is not pink in color, farmers are forced to purchase and add the synthetic astaxanthin dye to the diet of their fish.
About 1 in 20 wild-caught Alaska king (or Chinook) salmon are white in hue. The lack of pink or red hue is due to their genetics and their resulting inability to metabolize the astaxanthin that they consume. Within recent history, when these fish were caught they would be sold for considerably less than their pink and red counterparts, but today they have been branded as “ivory” and are sold for a premium as a delicacy.
What is salmon’s real color?
The real color of salmon is the silver, pink, green, gray, black, and blue of their scales when they are swimming in the bodies of water that provide them with their natural habitats. The real color of their flesh can fall within a wide range, from white to pink to orange or even a rich, bright red. What is often not real is the color that results when farmed salmon are given additives to replicate the vibrant colors of their wild counterparts.
The flesh of salmon in the wild can be vibrant red, pale pink, or even white. The red hues are the result of diets rich in shrimp, krill, and other species that contain high levels of astaxanthin. A wild-caught salmon with white flesh is genetically unable to process the astaxanthin, so their flesh remains pale.
Farmed salmon are fed synthetic astaxanthin so that they resemble their wild counterparts in color. These fish are not given the fresh krill and shrimp caught by wild salmon but instead subsist on pellets made out of the unwanted parts of other animals, smaller fish, gluten, and other ingredients. Because this diet does not naturally lend itself to turning the flesh of the salmon pink or red, farmers also give the salmon synthetic astaxanthin on the assumption that consumers will not purchase salmon that is white or gray in color and are instead willing to pay considerably more for flesh that is a vibrant red.
What it means when your salmon has “color added”
There are a couple of different things that the term “color added” on salmon filets or other salmon products can tell us. The first is that the fish is farm raised. We know this because farmers have to offer additional additives to farmed fish to accomplish a pink, orange, or red hue, whereas wild-caught salmon achieves the same, or an even more vibrant, color simply by having the opportunity to consume their natural diet.
The other thing that “color added” on salmon means is that the fish have likely been fed a synthetic form of astaxanthin, as the diet they are offered lacks the ability to turn their flesh a color that consumers would purchase.
Is “color added” safe?
Though the color additives in farmed salmon are concerning, of perhaps greater concern are the conditions in which the fish are often raised and the high likelihood of contamination. They are packed tightly into small tanks or sea nets and are often exposed to excessive chemicals and disease. In fact, it’s possible that one meal of farmed Atlantic salmon a month can expose you to contaminant levels exceeding the standards set by the World Health Organization.
Salmon are well known for the vibrant hues of their flesh, but the reality is that in most cases this hue is the result of additives given to farmed fish because they are not offered the same foods that their wild counterparts are eating. Their diet and the addition of synthetic materials to enhance the color of their flesh is not the only concerning aspect of farming salmon. Farmed salmon are also likely to have been exposed to a variety of other contaminants and diseases. The best way to avoid these additives and contaminants is simply to leave salmon off your plate.