Scientists at the U.S. Department of Agriculture have created an all-vegetarian feed for nine carnivorous fish species that can be used in aquaculture applications, according to Yale Environment 360. They say the new feed is useful in replacing fishmeal and other food supplies that are being stretched to their limits in a growing aquaculture sector.
The new feed is made with plant materials and incorporates vitamin supplements to make sure fish get the kind of nourishment they need to have healthy growth.
“I was told by many (people) that fish require fishmeal because that’s what they eat in the natural world,” said Rick Barrows, a fish physiologist with the USDA’s Research Service and one of the feed’s developers, in the post. “But that’s just wrong.”
He says the all-vegetarian feed could also help in sustaining fish stocks that have been hurt by overfishing across the world. Some of those, including sardines, anchovies, menhaden and other forage fish, are being depleted, at least partially, to make fishmeal in the first place.
But other researchers prefer fishmeal to the new feed, noting that fishmeal is still less expensive and has long been seen as the ideal way to support growing fish.
“Predatory fish like salmon tend to thrive in an aquaculture environment where they are fed things that they would eat in nature — fats and protein from other fish,” said Robert Reigh, director of the Aquaculture Research Station at Louisiana State University, in the article. “If you feed them things that they are not attuned to metabolically and physiologically, then you can have problems with poor growth and health problems.”