Fish as Feed/Fish as Food

Anglers call carp “trash fish” because of their many tiny bones. The U.S. government calls carp an invasive species because it can take over and devastate every watery environment they enter.

“Invasive carp (bighead, black, silver, and grass carp) outcompete native fish for food and space, starting at the base of the ecosystem,” said Wendy Sealey, fish physiologist with ARS. Sealey conducts her research at the Bozeman Fish Technology Center, in Bozeman, MT.

To help curb their numbers, in 2013, researchers began testing whether carp could be used as a replacement for wild-caught fish in aquatic animal feeds. Fish meal is an important and expensive ingredient used in aquafeeds, with an annual production of approximately 5 million tons.

Not only can carp be used as a feed ingredient for hybrid striped bass and rainbow trout, targeted fishing lowered carp populations in the project areas. That’s important because there’s a new interest in the targeted fishing of carp, this time from the restaurant community.

Restauranteurs large and small are now serving up carp to their customers under the re-branded name of “copi.” Even the World Wildlife Fund is promoting carp as pet food. Reportedly, copi is a flavorful fish, despite its high number of fine bones.

“Projects like the initial ARS study are still relevant because the issue of invasive carp is ongoing and evolving,” Sealey said. “The collaborative approach of the research and resource agency groups displays hope for how the complex issues [of invasive carp] extend well beyond just the science and require diverse team/approaches to have true impact.”