Figuring out what to do about the invasive northern snakeheads in Mid-Atlantic waterways has long perplexed state wildlife officials. Northern snakeheads, which are endemic to eastern Asia, reproduce prolifically, and then savagely protect their rapidly growing fry. Bass anglers throwing topwater frogs or flipping baits around vegetation often get an eye-opening experience when the brown, toothy fish absolutely crush their surface lures. However, the species negatively impact ecosystems as they prey on fish like shad and sunfish, creating ripple effects that impact larger game fish. Snakeheads have been in the United States for decades and used to be sold in pet stores, live fish food markets, and restaurants in several major cities. The interstate transport and possession of fish without a special permit have been banned since 2002.
Maryland Department of Natural Resources (MDNR) officials have been studying and trying to manage snakehead populations, along with invasive blue and flathead catfish, for years. In spring 2021, the agency operated a fish lift at the Conowingo Dam on the Susquehanna River to help native species during their migration while also trapping and removing snakeheads and flatheads. The project was a partnership between the MDNR, the dam owner, Exelon Corp, the Maryland Department of Agriculture, and local seafood wholesaler JJ McDonnell and Co. Besides removing the invasive fish from the Chesapeake Bay watershed, officials were able to add to their biological research data while also providing healthy meals to a local food bank.
Megan McGinn with the MDNR said that “approximately 2,000 pounds of northern snakehead were processed, which yielded 900 pounds of boneless filets. All were donated to the MD Food Bank for distribution. Each filet was individually vacuum-sealed, labeled, and frozen to ensure quality.”
This year’s effort was a pilot program that closed with the end of the spring migration. It is being evaluated for continuation in the future: “This initiative serves multiple goals, including controlling invasive fish species by harvesting them to minimize their impacts on the Chesapeake Bay ecosystem and providing protein-rich meals to those in need,” explained MDNR Secretary Jeannie Haddaway-Riccio. “We also will improve our collection of scientific data, which will help us better manage these invasives in the future.”
The fish lifts were installed on the east and west sides of the Conowingo Dam decades ago to allow the critical passage of migratory fish such as American shad and river herring. Exelon works closely with state and federal agencies to help these species access traditional spawning areas above the dam. One of the lifts was closed for spring 2021 to curb the movement of invasive species. The other has a series of gates and channels of water that attract and hold fish in a specialized hopper that was lifted over a sorting tank where biologists can quickly sort the fish. Shad, herring, and other native and game species were put into holding tanks and then trucked upstream to be released. Invasive snakeheads and catfish were removed.
“Despite the challenges invasive species have brought, we remain committed to working with MDNR on controlling this threat and operating in an environmentally responsible manner, including implementing creative solutions to ensure the safe passage of fish during the spawning season,” Conowingo Dam Plant Manager Dusty McKeown said.