An invasive fish becomes a tasty entree

Protecting the ecological health of the Chesapeake Bay requires many tools, and one of the most effective ones might soon be a dinner fork. 

The blue catfish – an invasive predator with few natural enemies – is overwhelming Virginia’s waterways, but researchers in the College of Agriculture and Life Sciences are working together to establish a market for them as a tasty and surprisingly nutritious food fish.

Blue catfish were first introduced to the Chesapeake Bay watershed in the 70s for sport fishing. With their tolerance for semi-salty water, a veritable smorgasbord of native species to eat, and few natural predators big enough to eat them, their populations surged. Today, it’s estimated the Chesapeake houses between 700 million and 1 billion pounds of blue catfish.

“At one processor in Tidewater, blue catfish have gone from less than 5 percent of the fish they purchased from local watermen each year to over 95 percent in less than 20 years,” said Mike Schwarz, director of the Virginia Seafood Agricultural Research and Extension Center (AREC). “There are so many now that they’re eating all of our blue crabs and clams, and now those valuable fisheries are being heavily impacted.”

State conservation agencies have tried to reduce their numbers through electrofishing, licensing incentives, and public education – to limited success. This is where Virginia Tech researchers like Schwarz see an opportunity.

“If we can make blue catfish commercially viable, we can create a market that manages the population through demand,” said Schwarz, who leads blue catfish research initiatives across Virginia Tech. “This is one of the bay’s biggest ecological and economic challenges, and we're bringing people, science, and industry to the same table to address it.”

Tasting the difference

Sean O’Keefe, professor in the Department of Food Science and Technology, is leading a project that aims to answer the single most important question required for a successful blue catfish market – do they taste good?

His team, which includes food science researchers David Kuhn, Yun Yin, and graduate student Taylor Peele, compared the taste of wild-caught blue catfish to farmed channel catfish, the variety most Americans are familiar with.

“We analyzed flavor compounds in both fish to establish the objective differences between them,” O’Keefe said. “After that, we needed to understand the subjective response consumers have to those properties, so Taylor ran sensory panels where volunteers tasted both fish and gave feedback.”

Their findings put to bed initial concerns that Americans might not deviate from the familiar flavor of channel catfish.

“We’re finding that the flavor is richer than farm-raised catfish,” O’Keefe said. “It has better long-chain fatty acids, and for people used to the taste of channel catfish, it was a refreshing change.”

Good for the Bay, good for you

It’s not just consumers’ tastebuds that blue catfish are good for. Their delectable flavor hides a surprisingly rich source of nutrients, according to Yiming Feng, associate professor in the Department of Biological Systems Engineering. 

Feng is leading an effort funded by the Virginia Department of Agricultural and Consumer Services’ (VDACS) Virginia Agricultural Council to study the nutritional quality of the fish. His team analyzed fillets sourced from processors in Virginia and Maryland and compared them to other common food fish.

They found that blue catfish has around 17 grams of protein per 100 grams of fish – higher than farmed channel catfish and comparable to salmon and cod. But they really shine when it comes to fat content, especially heart and brain healthy omega-3 fatty acids.

“The omega-3 content we’re getting is around 850 milligrams per 100 grams of fish,” Feng said. “That’s about five times higher than conventional catfish. Salmon, a strong omega-3 source, has about a thousand and something milligrams.”

This beats the American Heart Association’s daily omega-3 recommendation of 300 to 500 milligrams, which supports everything from improved cognition to lowered blood pressure.

From waste to worth

Haibo Huang, associate professor in the Department of Food Science and Technology, is working with Feng to address one of the most critical challenges in the commercialization of blue catfish: improving processing efficiency and profitability.

“Currently, 60 to 70 percent of the fish’s biomass is wasted,” Huang said. “Upcycling these wastes into value-added products can enhance the economic competitiveness of catfish processing.”

His team is exploring a number of these byproducts made from heads, tails, and skins – every part of the fish not taken for food. Their investigations include extracting collagen from the protein-rich skin for use in cosmetics and medical products and assessing whether antimicrobial compounds in the waste products could be used to help reduce food spoilage.

Expensive processing means expensive fillets in the grocery store, so Huang and Feng hope that by increasing the value of waste products from the current 10 cents per pound to their goal of 20 cents per pound, they can ultimately keep blue catfish fillets competitively priced on market shelves.

Collaborating with industry

Mike Hutt, executive director of the Virginia Marine Products Board, has worked closely with Schwarz to support blue catfish research and credits Virginia Tech with being the collaborative linchpin for so many statewide efforts.

“I appreciate what Michael and the folks at Virginia Tech are doing,” he said. “We’re all in this together, and the more they get people involved, the more ideas are thrown into the mix.”

One of the biggest remaining hurdles to commercial success, Hutt said, is consumer perception. Which is why he regularly brings blue catfish to trade shows, giving grocery buyers and chefs a taste of what the fish has to offer.

“The problem is getting everyone educated,” he said. “So, we let them taste it, and once they do that, it’s done. They’re sold.”