Ever pick up a beautifully pink salmon fillet at your local grocery store and wonder what makes that color so consistent, so perfect? That vibrant hue we’ve all come to associate with quality salmon isn’t always what nature intended. Let’s be real, most of us have no clue what happens behind the scenes before that fish lands on our plates. The story of farmed salmon and its signature pink color involves a chemical additive that’s become one of the aquaculture industry’s most closely guarded secrets. What you’re about to discover might change the way you look at that salmon dinner forever.
Without This Chemical, Your Salmon Would Be Gray
Here’s something that might shock you. Without astaxanthin in the diet, the flesh of farm-raised salmon is a grayish white. That’s right – the salmon you see in stores would naturally look more like a pale, unappealing beige or gray if farmers didn’t intervene. Without carotenoids, their flesh would look grey or beige, not pink or red, and you wouldn’t even be able to recognize these fillets as salmon.
Wild salmon get their natural pink to deep red color from eating krill, shrimp, and other small crustaceans in the ocean. Wild salmon take in astaxanthin from eating algae, krill, and other small crustaceans, which contain natural pigments called carotenoids. Farmed salmon, confined to pens and fed manufactured pellets, don’t have access to these natural food sources. So the aquaculture industry had to find another way to make their product marketable.
The Industry Uses a Color Chart to Pick the Perfect Pink
The SalmoFan color measurement scale by dsm-firmenich is recognized as the industry standard across the world for measuring salmon fillet color. Think about that for a moment. Salmon farmers literally choose the shade of pink they want their fish to be, much like you’d pick paint colors at a hardware store. 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.
This color fan ranges from pale salmon pink to bright orange-red, with numbered shades that farmers can target. There is variation in their target for the lowest acceptable colour, ranging from 24 to 27 on the SalmoFan scale and between 5 and 7 milligrams of astaxanthin per kilogram of fillet. The darker the desired color, the more astaxanthin must be added to the feed. Research shows that consumers are willing to pay more for darker-hued salmon, creating a financial incentive for farmers to amp up the pigment levels. Wealthy shoppers go for darker-hued salmon, which fetch up to $1 per pound more than lighter shades, and farmed salmon colored lower than 23 on SalmoFan to be “difficult to sell at any price”.
Synthetic vs. Natural Astaxanthin: A Critical Difference
According to one of the world’s leading manufacturers, AlgaTech, “essentially all” astaxanthin used in aquaculture is a petrochemical product. Yes, you read that correctly – petrochemical. The vast majority of farmed salmon are fed synthetic astaxanthin derived from petroleum-based chemicals, not natural sources. Chemical synthesis of astaxanthin is currently the most cost-effective, and thus its synthetic preparations have dominated over 95% of the feed market.
Natural astaxanthin exists, extracted from algae like Haematococcus pluvialis, but there’s a catch. Naturally-sourced astaxanthin is available – but it’s four times as expensive. This cost difference means most salmon farmers opt for the cheaper synthetic version. Synthetic astaxanthin comes in all three forms (RR, RS, and SS), and 25 percent of it is the naturally occurring SS form, and synthetic astaxanthin has not been specifically approved for direct human consumption, but it is legal to use in salmon feed. The molecular structure differs from natural astaxanthin, raising questions about how our bodies process it.
While more than 30 studies have been done on the safety of natural astaxanthin for direct human consumption, fewer have been done on direct consumption of synthetic astaxanthin, though the efficacy of natural astaxanthin has also been proven in over 100 studies. This gap in research is concerning. As natural and synthetic astaxanthin differ in their structure, it is not certain how long-term consumption of synthetic astaxanthin may affect human health.
Astaxanthin Is the Most Expensive Part of Salmon Feed
The pigmenting compound doesn’t come cheap, even in its synthetic form. It is the most expensive element of salmon feed, taking up nearly 20% of total fish feed costs according to research from 2011. This makes astaxanthin supplementation a significant investment for salmon farmers, yet they continue to use it because the alternative – selling gray salmon – simply isn’t viable in today’s market.
Controlling and optimizing the concentration of astaxanthin in fish food is time and labor intensive, requiring careful monitoring to achieve the desired color while managing costs. The entire process reveals how heavily industrialized salmon farming has become. Wild salmon contain roughly four times more astaxanthin than their farmed counterparts. Wild salmon have four times higher astaxanthin content than farmed salmon and contain natural astaxanthin instead of synthetic astaxanthin.
The Contamination Concerns Beyond Color
The synthetic astaxanthin issue is just one piece of a larger puzzle. Farmed salmon are fattier which means they can accumulate higher levels of toxins such as PCBs, and studies have found higher levels of these harmful chemicals in farmed salmon in some regions than in wild salmon. These persistent organic pollutants were banned decades ago but remain in the environment and concentrate in fish oils used in salmon feed.
Farm-raised Atlantic salmon had significantly higher levels of 13 toxins when compared with wild Pacific salmon according to a comprehensive 2004 study published in Science. Researchers at Arizona State University discovered increases in drug-resistant antibiotics in farmed seafood over the past 30 years, leading to concerns about increased risk of antibiotic resistance in humans. The cramped conditions in salmon farms create disease-prone environments that require chemical interventions to keep fish alive until harvest.
In Chile, the world’s second largest producer of salmon, aquaculture is considered the primary source of antibiotics residues in the coastal waters of northern Patagonia, and a higher adaptation to antibiotics was revealed by a greater proportion of multi-resistant bacteria isolated from the surface seawater of the salmon farming area. The environmental impact extends far beyond individual fish consumption, affecting entire marine ecosystems.
Looking at your next salmon purchase differently now? The pink color that signals freshness and quality to most consumers is actually a carefully engineered marketing strategy, one that relies on synthetic chemicals and industrial processes far removed from the pristine ocean imagery used in advertising. Wild salmon naturally accumulate astaxanthin through their diet, resulting in varied, authentic coloration that reflects their environment and what they’ve eaten. Farmed salmon, by contrast, are fed precise amounts of synthetic pigment to achieve uniform appearance. What matters most is knowing what you’re actually buying. Did you expect salmon farming to involve paint-by-numbers color selection and petroleum-derived additives?
