Farm-raised salmon and trout may soon be fed tomatoes that were genetically modified with a bacterial gene.
Salmon and trout living in the wild eat foods, like crustaceans and insects, that naturally contain pigments. Those pigments turn their flesh pink or red. Farm-raised fish, on the other hand, don’t have access to those natural sources of food. Instead, they are often fed dry pellets that can contain a wide variety of ingredients, including: soy, corn, canola oil, poultry, and antibiotics.
Consequently, the flesh of farm-raised fish can be pale pink, white, or even gray. So, they are often fed dyes to make the fish look like wild-caught fish. The dyes are commonly derived from petroleum or more “natural” sources like algae or pulverized crustaceans.
But, now there’s a new option – a “natural” dye from genetically modified tomatoes.
Tomatoes naturally produce carotenoids, which give them a red color. But, the concentration wasn’t high enough to be used as a dye in fish food. So, scientist added bacterial DNA (associated with ketocarotenoid production) to a tomato, forcing it to produce more of the colorful compounds. But, the level of the coloring agent still wasn’t high enough. So, that genetically modified tomato was crossed with a tomato that is very high in beta-carotene. The result was a genetically modified tomato that produced high levels of the desired colorful compounds.
The genetically modified tomatoes were grown and freeze-dried in the United Kingdom and then shipped to Germany where they were turned into a powder and added to the feed for farmed trout.
What You Can Do:
1. Choose wild caught varieties of fish.
2. If you choose to eat farm-raised fish, ask which chemicals were used to color the flesh.