The interview is part of a new series filmed by The Fish Site’s team at dsm-firmenich’s recent Global Aqua Days event in Athens. In it, Johnsen – whose family has been supplying synthetic astaxanthin to the aquaculture industry since the 1970s – discusses the benefits of the carotenoid compound with The Fish Site’s Moritz Mueller.
As Johnsen explains, while often perceived by consumers as a purely cosmetic additive, astaxanthin is far more than a pigment – it is essential for fish health, performance and reproduction.
In the early days of salmon farming, farmers supplemented feeds with shrimp byproducts as a natural source of astaxanthin. However, these proved inconsistent and insufficient. A breakthrough came in the 1970s, when the molecule was chemically isolated, enabling consistent large-scale production, and soon synthetic astaxanthin became the industry standard.
As Johnsen notes, astaxanthin serves as a powerful antioxidant – supporting growth, stress resistance, and immune function. In female salmon, for example, astaxanthin enhances egg viability and fry survival, while in males it contributes to skin colouration used in mating signals. It also helps fish manage environmental stressors by mobilizing antioxidant defences, especially during periods of rapid growth or seasonal temperature changes.
While there are several different sources of astaxanthin – namely synthetic, yeast-, or algae-derived – all have the same impact and, for consumers, astaxanthin contributes not only to salmon’s visual appeal but also to its nutritional profile.
The dsm-firmenich-sponsored series also includes interviews with Gorjan Nikolik, senior seafood analyst at Rabobank; Luis Fernando Auranguren, a leading figure in shrimp health and production, focusing on the health challenges facing shrimp farmers in Latin America; Brett Glencross, technical director of IFFO, comparing a range of aquafeed ingredients; John Costatino, COO of Manolin, focusing on technological innovations; as well as the company's own Corinne Bonadei, Sebastain Rider and Benedict Standen.
