Invasive river carp: From pest to opportunity

The water is placid as Mitchell Rosandich from the Illinois Department of Natural Resources and WWF’s Bex Young drift along the Mississippi River. But when their boat engine rumbles to life, hundreds of startled silver carp begin rocketing into the air. Onboard, the two try to dodge the rain of frenzied fish—and learn what it would take to create a viable consumer market for the species.

Besides being high-flying, silver carp are voracious, prolific, and unimpeded by any natural predator in North America. Since escaping aquaculture farms 50 years ago, they’ve overrun Midwestern rivers, crowding out native fish and disrupting food webs. Now, they’re barreling toward the Great Lakes, putting the planet’s largest freshwater system—and the livelihoods of commercial fishers—at risk.

“Invasive carp will likely never be entirely eradicated, but with increased fishing, they may be slowed enough to restore some ecosystems and spare the Great Lakes,” says Julia Kurnik, WWF’s senior director of Innovation Start-ups.

But how do you make it worthwhile to catch a bony fish for which Americans have little appetite?

The answer, according to Kurnik, could be pet food. Pet companies are on the hunt for alternative proteins, and carp is cheap, plentiful, and nutrient-rich. But brands won’t use the fish in products without a steady supply, and suppliers won’t invest in processing without a steady demand. So WWF is partnering with pet companies to build that market, a solution that could stave off environmental degradation and boost the economy—in essence, killing two fish with one stone.

WWF is grateful to John McDonnell for his visionary support, which is helping turn the threat of invasive carp into a model for sustainable economic growth.