Is farmed salmon being "dyed"?

02 November 2016 | What's astaxanthin, and what's it doing in farmed salmon?

Pigment perfect

ABC's Four Corners program 'Big Fish', investigating the salmon farming industry in Tasmania, left consumers feeling rattled this week. 

Environmental and sustainability issues aside, what got many people talking on social media were claims of farmed fish being fed a synthetic pigment in order to achieve the pink colour we expect from salmon flesh.

For many, this information was an unwelcome revelation.

Why's salmon pink?

Wild salmon gets its distinctive pink flesh from a substance called astaxanthin, a pigment found in shrimp-like krill and other crustaceans that the salmon eats.  

The Four Corners program revealed that farmed fish are often fed a synthetic version of astaxanthin, without which they would be grey or off-white in colour. 

On its website, Tassal – the salmon fishery at the centre of the Four Corners report – writes that astaxanthin is not just a pigment. It plays a role in the fish's immune system, and is "added to the diets of farmed salmon to ensure our salmon are healthy and have all the nutrients they require and also that the flesh has the rich colour that our consumers seek." 

It assures readers that "Whilst astaxanthin is synthesised it must be stressed that this is a pure version of what is eaten by wild salmon, this is why we refer to it as nature-identical. The vast majority of farmed salmon around the world are fed diets with nature-identical astaxanthin." 

Need-to-know basis

But it's clear from the buzz around the issue that consumers aren't happy about being kept in the dark about what's going into their food. 

We asked members of our Facebook community if they were aware that supermarket salmon might be artificially coloured, and here are just a few of the comments we received:

Tell us what you think about astaxanthin in farmed salmon in the comments section.